xref: /linux/fs/smb/server/vfs_cache.c (revision 55d0969c451159cff86949b38c39171cab962069)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2016 Namjae Jeon <linkinjeon@kernel.org>
4  * Copyright (C) 2019 Samsung Electronics Co., Ltd.
5  */
6 
7 #include <linux/fs.h>
8 #include <linux/filelock.h>
9 #include <linux/slab.h>
10 #include <linux/vmalloc.h>
11 #include <linux/kthread.h>
12 #include <linux/freezer.h>
13 
14 #include "glob.h"
15 #include "vfs_cache.h"
16 #include "oplock.h"
17 #include "vfs.h"
18 #include "connection.h"
19 #include "mgmt/tree_connect.h"
20 #include "mgmt/user_session.h"
21 #include "smb_common.h"
22 #include "server.h"
23 
24 #define S_DEL_PENDING			1
25 #define S_DEL_ON_CLS			2
26 #define S_DEL_ON_CLS_STREAM		8
27 
28 static unsigned int inode_hash_mask __read_mostly;
29 static unsigned int inode_hash_shift __read_mostly;
30 static struct hlist_head *inode_hashtable __read_mostly;
31 static DEFINE_RWLOCK(inode_hash_lock);
32 
33 static struct ksmbd_file_table global_ft;
34 static atomic_long_t fd_limit;
35 static struct kmem_cache *filp_cache;
36 
37 static bool durable_scavenger_running;
38 static DEFINE_MUTEX(durable_scavenger_lock);
39 static wait_queue_head_t dh_wq;
40 
41 void ksmbd_set_fd_limit(unsigned long limit)
42 {
43 	limit = min(limit, get_max_files());
44 	atomic_long_set(&fd_limit, limit);
45 }
46 
47 static bool fd_limit_depleted(void)
48 {
49 	long v = atomic_long_dec_return(&fd_limit);
50 
51 	if (v >= 0)
52 		return false;
53 	atomic_long_inc(&fd_limit);
54 	return true;
55 }
56 
57 static void fd_limit_close(void)
58 {
59 	atomic_long_inc(&fd_limit);
60 }
61 
62 /*
63  * INODE hash
64  */
65 
66 static unsigned long inode_hash(struct super_block *sb, unsigned long hashval)
67 {
68 	unsigned long tmp;
69 
70 	tmp = (hashval * (unsigned long)sb) ^ (GOLDEN_RATIO_PRIME + hashval) /
71 		L1_CACHE_BYTES;
72 	tmp = tmp ^ ((tmp ^ GOLDEN_RATIO_PRIME) >> inode_hash_shift);
73 	return tmp & inode_hash_mask;
74 }
75 
76 static struct ksmbd_inode *__ksmbd_inode_lookup(struct dentry *de)
77 {
78 	struct hlist_head *head = inode_hashtable +
79 		inode_hash(d_inode(de)->i_sb, (unsigned long)de);
80 	struct ksmbd_inode *ci = NULL, *ret_ci = NULL;
81 
82 	hlist_for_each_entry(ci, head, m_hash) {
83 		if (ci->m_de == de) {
84 			if (atomic_inc_not_zero(&ci->m_count))
85 				ret_ci = ci;
86 			break;
87 		}
88 	}
89 	return ret_ci;
90 }
91 
92 static struct ksmbd_inode *ksmbd_inode_lookup(struct ksmbd_file *fp)
93 {
94 	return __ksmbd_inode_lookup(fp->filp->f_path.dentry);
95 }
96 
97 struct ksmbd_inode *ksmbd_inode_lookup_lock(struct dentry *d)
98 {
99 	struct ksmbd_inode *ci;
100 
101 	read_lock(&inode_hash_lock);
102 	ci = __ksmbd_inode_lookup(d);
103 	read_unlock(&inode_hash_lock);
104 
105 	return ci;
106 }
107 
108 int ksmbd_query_inode_status(struct dentry *dentry)
109 {
110 	struct ksmbd_inode *ci;
111 	int ret = KSMBD_INODE_STATUS_UNKNOWN;
112 
113 	read_lock(&inode_hash_lock);
114 	ci = __ksmbd_inode_lookup(dentry);
115 	if (ci) {
116 		ret = KSMBD_INODE_STATUS_OK;
117 		if (ci->m_flags & (S_DEL_PENDING | S_DEL_ON_CLS))
118 			ret = KSMBD_INODE_STATUS_PENDING_DELETE;
119 		atomic_dec(&ci->m_count);
120 	}
121 	read_unlock(&inode_hash_lock);
122 	return ret;
123 }
124 
125 bool ksmbd_inode_pending_delete(struct ksmbd_file *fp)
126 {
127 	return (fp->f_ci->m_flags & (S_DEL_PENDING | S_DEL_ON_CLS));
128 }
129 
130 void ksmbd_set_inode_pending_delete(struct ksmbd_file *fp)
131 {
132 	fp->f_ci->m_flags |= S_DEL_PENDING;
133 }
134 
135 void ksmbd_clear_inode_pending_delete(struct ksmbd_file *fp)
136 {
137 	fp->f_ci->m_flags &= ~S_DEL_PENDING;
138 }
139 
140 void ksmbd_fd_set_delete_on_close(struct ksmbd_file *fp,
141 				  int file_info)
142 {
143 	if (ksmbd_stream_fd(fp)) {
144 		fp->f_ci->m_flags |= S_DEL_ON_CLS_STREAM;
145 		return;
146 	}
147 
148 	fp->f_ci->m_flags |= S_DEL_ON_CLS;
149 }
150 
151 static void ksmbd_inode_hash(struct ksmbd_inode *ci)
152 {
153 	struct hlist_head *b = inode_hashtable +
154 		inode_hash(d_inode(ci->m_de)->i_sb, (unsigned long)ci->m_de);
155 
156 	hlist_add_head(&ci->m_hash, b);
157 }
158 
159 static void ksmbd_inode_unhash(struct ksmbd_inode *ci)
160 {
161 	write_lock(&inode_hash_lock);
162 	hlist_del_init(&ci->m_hash);
163 	write_unlock(&inode_hash_lock);
164 }
165 
166 static int ksmbd_inode_init(struct ksmbd_inode *ci, struct ksmbd_file *fp)
167 {
168 	atomic_set(&ci->m_count, 1);
169 	atomic_set(&ci->op_count, 0);
170 	atomic_set(&ci->sop_count, 0);
171 	ci->m_flags = 0;
172 	ci->m_fattr = 0;
173 	INIT_LIST_HEAD(&ci->m_fp_list);
174 	INIT_LIST_HEAD(&ci->m_op_list);
175 	init_rwsem(&ci->m_lock);
176 	ci->m_de = fp->filp->f_path.dentry;
177 	return 0;
178 }
179 
180 static struct ksmbd_inode *ksmbd_inode_get(struct ksmbd_file *fp)
181 {
182 	struct ksmbd_inode *ci, *tmpci;
183 	int rc;
184 
185 	read_lock(&inode_hash_lock);
186 	ci = ksmbd_inode_lookup(fp);
187 	read_unlock(&inode_hash_lock);
188 	if (ci)
189 		return ci;
190 
191 	ci = kmalloc(sizeof(struct ksmbd_inode), GFP_KERNEL);
192 	if (!ci)
193 		return NULL;
194 
195 	rc = ksmbd_inode_init(ci, fp);
196 	if (rc) {
197 		pr_err("inode initialized failed\n");
198 		kfree(ci);
199 		return NULL;
200 	}
201 
202 	write_lock(&inode_hash_lock);
203 	tmpci = ksmbd_inode_lookup(fp);
204 	if (!tmpci) {
205 		ksmbd_inode_hash(ci);
206 	} else {
207 		kfree(ci);
208 		ci = tmpci;
209 	}
210 	write_unlock(&inode_hash_lock);
211 	return ci;
212 }
213 
214 static void ksmbd_inode_free(struct ksmbd_inode *ci)
215 {
216 	ksmbd_inode_unhash(ci);
217 	kfree(ci);
218 }
219 
220 void ksmbd_inode_put(struct ksmbd_inode *ci)
221 {
222 	if (atomic_dec_and_test(&ci->m_count))
223 		ksmbd_inode_free(ci);
224 }
225 
226 int __init ksmbd_inode_hash_init(void)
227 {
228 	unsigned int loop;
229 	unsigned long numentries = 16384;
230 	unsigned long bucketsize = sizeof(struct hlist_head);
231 	unsigned long size;
232 
233 	inode_hash_shift = ilog2(numentries);
234 	inode_hash_mask = (1 << inode_hash_shift) - 1;
235 
236 	size = bucketsize << inode_hash_shift;
237 
238 	/* init master fp hash table */
239 	inode_hashtable = vmalloc(size);
240 	if (!inode_hashtable)
241 		return -ENOMEM;
242 
243 	for (loop = 0; loop < (1U << inode_hash_shift); loop++)
244 		INIT_HLIST_HEAD(&inode_hashtable[loop]);
245 	return 0;
246 }
247 
248 void ksmbd_release_inode_hash(void)
249 {
250 	vfree(inode_hashtable);
251 }
252 
253 static void __ksmbd_inode_close(struct ksmbd_file *fp)
254 {
255 	struct ksmbd_inode *ci = fp->f_ci;
256 	int err;
257 	struct file *filp;
258 
259 	filp = fp->filp;
260 	if (ksmbd_stream_fd(fp) && (ci->m_flags & S_DEL_ON_CLS_STREAM)) {
261 		ci->m_flags &= ~S_DEL_ON_CLS_STREAM;
262 		err = ksmbd_vfs_remove_xattr(file_mnt_idmap(filp),
263 					     &filp->f_path,
264 					     fp->stream.name,
265 					     true);
266 		if (err)
267 			pr_err("remove xattr failed : %s\n",
268 			       fp->stream.name);
269 	}
270 
271 	if (atomic_dec_and_test(&ci->m_count)) {
272 		down_write(&ci->m_lock);
273 		if (ci->m_flags & (S_DEL_ON_CLS | S_DEL_PENDING)) {
274 			ci->m_flags &= ~(S_DEL_ON_CLS | S_DEL_PENDING);
275 			up_write(&ci->m_lock);
276 			ksmbd_vfs_unlink(filp);
277 			down_write(&ci->m_lock);
278 		}
279 		up_write(&ci->m_lock);
280 
281 		ksmbd_inode_free(ci);
282 	}
283 }
284 
285 static void __ksmbd_remove_durable_fd(struct ksmbd_file *fp)
286 {
287 	if (!has_file_id(fp->persistent_id))
288 		return;
289 
290 	idr_remove(global_ft.idr, fp->persistent_id);
291 }
292 
293 static void ksmbd_remove_durable_fd(struct ksmbd_file *fp)
294 {
295 	write_lock(&global_ft.lock);
296 	__ksmbd_remove_durable_fd(fp);
297 	write_unlock(&global_ft.lock);
298 	if (waitqueue_active(&dh_wq))
299 		wake_up(&dh_wq);
300 }
301 
302 static void __ksmbd_remove_fd(struct ksmbd_file_table *ft, struct ksmbd_file *fp)
303 {
304 	if (!has_file_id(fp->volatile_id))
305 		return;
306 
307 	down_write(&fp->f_ci->m_lock);
308 	list_del_init(&fp->node);
309 	up_write(&fp->f_ci->m_lock);
310 
311 	write_lock(&ft->lock);
312 	idr_remove(ft->idr, fp->volatile_id);
313 	write_unlock(&ft->lock);
314 }
315 
316 static void __ksmbd_close_fd(struct ksmbd_file_table *ft, struct ksmbd_file *fp)
317 {
318 	struct file *filp;
319 	struct ksmbd_lock *smb_lock, *tmp_lock;
320 
321 	fd_limit_close();
322 	ksmbd_remove_durable_fd(fp);
323 	if (ft)
324 		__ksmbd_remove_fd(ft, fp);
325 
326 	close_id_del_oplock(fp);
327 	filp = fp->filp;
328 
329 	__ksmbd_inode_close(fp);
330 	if (!IS_ERR_OR_NULL(filp))
331 		fput(filp);
332 
333 	/* because the reference count of fp is 0, it is guaranteed that
334 	 * there are not accesses to fp->lock_list.
335 	 */
336 	list_for_each_entry_safe(smb_lock, tmp_lock, &fp->lock_list, flist) {
337 		spin_lock(&fp->conn->llist_lock);
338 		list_del(&smb_lock->clist);
339 		spin_unlock(&fp->conn->llist_lock);
340 
341 		list_del(&smb_lock->flist);
342 		locks_free_lock(smb_lock->fl);
343 		kfree(smb_lock);
344 	}
345 
346 	if (ksmbd_stream_fd(fp))
347 		kfree(fp->stream.name);
348 	kmem_cache_free(filp_cache, fp);
349 }
350 
351 static struct ksmbd_file *ksmbd_fp_get(struct ksmbd_file *fp)
352 {
353 	if (fp->f_state != FP_INITED)
354 		return NULL;
355 
356 	if (!atomic_inc_not_zero(&fp->refcount))
357 		return NULL;
358 	return fp;
359 }
360 
361 static struct ksmbd_file *__ksmbd_lookup_fd(struct ksmbd_file_table *ft,
362 					    u64 id)
363 {
364 	struct ksmbd_file *fp;
365 
366 	if (!has_file_id(id))
367 		return NULL;
368 
369 	read_lock(&ft->lock);
370 	fp = idr_find(ft->idr, id);
371 	if (fp)
372 		fp = ksmbd_fp_get(fp);
373 	read_unlock(&ft->lock);
374 	return fp;
375 }
376 
377 static void __put_fd_final(struct ksmbd_work *work, struct ksmbd_file *fp)
378 {
379 	__ksmbd_close_fd(&work->sess->file_table, fp);
380 	atomic_dec(&work->conn->stats.open_files_count);
381 }
382 
383 static void set_close_state_blocked_works(struct ksmbd_file *fp)
384 {
385 	struct ksmbd_work *cancel_work;
386 
387 	spin_lock(&fp->f_lock);
388 	list_for_each_entry(cancel_work, &fp->blocked_works,
389 				 fp_entry) {
390 		cancel_work->state = KSMBD_WORK_CLOSED;
391 		cancel_work->cancel_fn(cancel_work->cancel_argv);
392 	}
393 	spin_unlock(&fp->f_lock);
394 }
395 
396 int ksmbd_close_fd(struct ksmbd_work *work, u64 id)
397 {
398 	struct ksmbd_file	*fp;
399 	struct ksmbd_file_table	*ft;
400 
401 	if (!has_file_id(id))
402 		return 0;
403 
404 	ft = &work->sess->file_table;
405 	write_lock(&ft->lock);
406 	fp = idr_find(ft->idr, id);
407 	if (fp) {
408 		set_close_state_blocked_works(fp);
409 
410 		if (fp->f_state != FP_INITED)
411 			fp = NULL;
412 		else {
413 			fp->f_state = FP_CLOSED;
414 			if (!atomic_dec_and_test(&fp->refcount))
415 				fp = NULL;
416 		}
417 	}
418 	write_unlock(&ft->lock);
419 
420 	if (!fp)
421 		return -EINVAL;
422 
423 	__put_fd_final(work, fp);
424 	return 0;
425 }
426 
427 void ksmbd_fd_put(struct ksmbd_work *work, struct ksmbd_file *fp)
428 {
429 	if (!fp)
430 		return;
431 
432 	if (!atomic_dec_and_test(&fp->refcount))
433 		return;
434 	__put_fd_final(work, fp);
435 }
436 
437 static bool __sanity_check(struct ksmbd_tree_connect *tcon, struct ksmbd_file *fp)
438 {
439 	if (!fp)
440 		return false;
441 	if (fp->tcon != tcon)
442 		return false;
443 	return true;
444 }
445 
446 struct ksmbd_file *ksmbd_lookup_foreign_fd(struct ksmbd_work *work, u64 id)
447 {
448 	return __ksmbd_lookup_fd(&work->sess->file_table, id);
449 }
450 
451 struct ksmbd_file *ksmbd_lookup_fd_fast(struct ksmbd_work *work, u64 id)
452 {
453 	struct ksmbd_file *fp = __ksmbd_lookup_fd(&work->sess->file_table, id);
454 
455 	if (__sanity_check(work->tcon, fp))
456 		return fp;
457 
458 	ksmbd_fd_put(work, fp);
459 	return NULL;
460 }
461 
462 struct ksmbd_file *ksmbd_lookup_fd_slow(struct ksmbd_work *work, u64 id,
463 					u64 pid)
464 {
465 	struct ksmbd_file *fp;
466 
467 	if (!has_file_id(id)) {
468 		id = work->compound_fid;
469 		pid = work->compound_pfid;
470 	}
471 
472 	fp = __ksmbd_lookup_fd(&work->sess->file_table, id);
473 	if (!__sanity_check(work->tcon, fp)) {
474 		ksmbd_fd_put(work, fp);
475 		return NULL;
476 	}
477 	if (fp->persistent_id != pid) {
478 		ksmbd_fd_put(work, fp);
479 		return NULL;
480 	}
481 	return fp;
482 }
483 
484 struct ksmbd_file *ksmbd_lookup_global_fd(unsigned long long id)
485 {
486 	return __ksmbd_lookup_fd(&global_ft, id);
487 }
488 
489 struct ksmbd_file *ksmbd_lookup_durable_fd(unsigned long long id)
490 {
491 	struct ksmbd_file *fp;
492 
493 	fp = __ksmbd_lookup_fd(&global_ft, id);
494 	if (fp && (fp->conn ||
495 		   (fp->durable_scavenger_timeout &&
496 		    (fp->durable_scavenger_timeout <
497 		     jiffies_to_msecs(jiffies))))) {
498 		ksmbd_put_durable_fd(fp);
499 		fp = NULL;
500 	}
501 
502 	return fp;
503 }
504 
505 void ksmbd_put_durable_fd(struct ksmbd_file *fp)
506 {
507 	if (!atomic_dec_and_test(&fp->refcount))
508 		return;
509 
510 	__ksmbd_close_fd(NULL, fp);
511 }
512 
513 struct ksmbd_file *ksmbd_lookup_fd_cguid(char *cguid)
514 {
515 	struct ksmbd_file	*fp = NULL;
516 	unsigned int		id;
517 
518 	read_lock(&global_ft.lock);
519 	idr_for_each_entry(global_ft.idr, fp, id) {
520 		if (!memcmp(fp->create_guid,
521 			    cguid,
522 			    SMB2_CREATE_GUID_SIZE)) {
523 			fp = ksmbd_fp_get(fp);
524 			break;
525 		}
526 	}
527 	read_unlock(&global_ft.lock);
528 
529 	return fp;
530 }
531 
532 struct ksmbd_file *ksmbd_lookup_fd_inode(struct dentry *dentry)
533 {
534 	struct ksmbd_file	*lfp;
535 	struct ksmbd_inode	*ci;
536 	struct inode		*inode = d_inode(dentry);
537 
538 	read_lock(&inode_hash_lock);
539 	ci = __ksmbd_inode_lookup(dentry);
540 	read_unlock(&inode_hash_lock);
541 	if (!ci)
542 		return NULL;
543 
544 	down_read(&ci->m_lock);
545 	list_for_each_entry(lfp, &ci->m_fp_list, node) {
546 		if (inode == file_inode(lfp->filp)) {
547 			atomic_dec(&ci->m_count);
548 			lfp = ksmbd_fp_get(lfp);
549 			up_read(&ci->m_lock);
550 			return lfp;
551 		}
552 	}
553 	atomic_dec(&ci->m_count);
554 	up_read(&ci->m_lock);
555 	return NULL;
556 }
557 
558 #define OPEN_ID_TYPE_VOLATILE_ID	(0)
559 #define OPEN_ID_TYPE_PERSISTENT_ID	(1)
560 
561 static void __open_id_set(struct ksmbd_file *fp, u64 id, int type)
562 {
563 	if (type == OPEN_ID_TYPE_VOLATILE_ID)
564 		fp->volatile_id = id;
565 	if (type == OPEN_ID_TYPE_PERSISTENT_ID)
566 		fp->persistent_id = id;
567 }
568 
569 static int __open_id(struct ksmbd_file_table *ft, struct ksmbd_file *fp,
570 		     int type)
571 {
572 	u64			id = 0;
573 	int			ret;
574 
575 	if (type == OPEN_ID_TYPE_VOLATILE_ID && fd_limit_depleted()) {
576 		__open_id_set(fp, KSMBD_NO_FID, type);
577 		return -EMFILE;
578 	}
579 
580 	idr_preload(GFP_KERNEL);
581 	write_lock(&ft->lock);
582 	ret = idr_alloc_cyclic(ft->idr, fp, 0, INT_MAX - 1, GFP_NOWAIT);
583 	if (ret >= 0) {
584 		id = ret;
585 		ret = 0;
586 	} else {
587 		id = KSMBD_NO_FID;
588 		fd_limit_close();
589 	}
590 
591 	__open_id_set(fp, id, type);
592 	write_unlock(&ft->lock);
593 	idr_preload_end();
594 	return ret;
595 }
596 
597 unsigned int ksmbd_open_durable_fd(struct ksmbd_file *fp)
598 {
599 	__open_id(&global_ft, fp, OPEN_ID_TYPE_PERSISTENT_ID);
600 	return fp->persistent_id;
601 }
602 
603 struct ksmbd_file *ksmbd_open_fd(struct ksmbd_work *work, struct file *filp)
604 {
605 	struct ksmbd_file *fp;
606 	int ret;
607 
608 	fp = kmem_cache_zalloc(filp_cache, GFP_KERNEL);
609 	if (!fp) {
610 		pr_err("Failed to allocate memory\n");
611 		return ERR_PTR(-ENOMEM);
612 	}
613 
614 	INIT_LIST_HEAD(&fp->blocked_works);
615 	INIT_LIST_HEAD(&fp->node);
616 	INIT_LIST_HEAD(&fp->lock_list);
617 	spin_lock_init(&fp->f_lock);
618 	atomic_set(&fp->refcount, 1);
619 
620 	fp->filp		= filp;
621 	fp->conn		= work->conn;
622 	fp->tcon		= work->tcon;
623 	fp->volatile_id		= KSMBD_NO_FID;
624 	fp->persistent_id	= KSMBD_NO_FID;
625 	fp->f_state		= FP_NEW;
626 	fp->f_ci		= ksmbd_inode_get(fp);
627 
628 	if (!fp->f_ci) {
629 		ret = -ENOMEM;
630 		goto err_out;
631 	}
632 
633 	ret = __open_id(&work->sess->file_table, fp, OPEN_ID_TYPE_VOLATILE_ID);
634 	if (ret) {
635 		ksmbd_inode_put(fp->f_ci);
636 		goto err_out;
637 	}
638 
639 	atomic_inc(&work->conn->stats.open_files_count);
640 	return fp;
641 
642 err_out:
643 	kmem_cache_free(filp_cache, fp);
644 	return ERR_PTR(ret);
645 }
646 
647 void ksmbd_update_fstate(struct ksmbd_file_table *ft, struct ksmbd_file *fp,
648 			 unsigned int state)
649 {
650 	if (!fp)
651 		return;
652 
653 	write_lock(&ft->lock);
654 	fp->f_state = state;
655 	write_unlock(&ft->lock);
656 }
657 
658 static int
659 __close_file_table_ids(struct ksmbd_file_table *ft,
660 		       struct ksmbd_tree_connect *tcon,
661 		       bool (*skip)(struct ksmbd_tree_connect *tcon,
662 				    struct ksmbd_file *fp))
663 {
664 	unsigned int			id;
665 	struct ksmbd_file		*fp;
666 	int				num = 0;
667 
668 	idr_for_each_entry(ft->idr, fp, id) {
669 		if (skip(tcon, fp))
670 			continue;
671 
672 		set_close_state_blocked_works(fp);
673 
674 		if (!atomic_dec_and_test(&fp->refcount))
675 			continue;
676 		__ksmbd_close_fd(ft, fp);
677 		num++;
678 	}
679 	return num;
680 }
681 
682 static inline bool is_reconnectable(struct ksmbd_file *fp)
683 {
684 	struct oplock_info *opinfo = opinfo_get(fp);
685 	bool reconn = false;
686 
687 	if (!opinfo)
688 		return false;
689 
690 	if (opinfo->op_state != OPLOCK_STATE_NONE) {
691 		opinfo_put(opinfo);
692 		return false;
693 	}
694 
695 	if (fp->is_resilient || fp->is_persistent)
696 		reconn = true;
697 	else if (fp->is_durable && opinfo->is_lease &&
698 		 opinfo->o_lease->state & SMB2_LEASE_HANDLE_CACHING_LE)
699 		reconn = true;
700 
701 	else if (fp->is_durable && opinfo->level == SMB2_OPLOCK_LEVEL_BATCH)
702 		reconn = true;
703 
704 	opinfo_put(opinfo);
705 	return reconn;
706 }
707 
708 static bool tree_conn_fd_check(struct ksmbd_tree_connect *tcon,
709 			       struct ksmbd_file *fp)
710 {
711 	return fp->tcon != tcon;
712 }
713 
714 static bool ksmbd_durable_scavenger_alive(void)
715 {
716 	mutex_lock(&durable_scavenger_lock);
717 	if (!durable_scavenger_running) {
718 		mutex_unlock(&durable_scavenger_lock);
719 		return false;
720 	}
721 	mutex_unlock(&durable_scavenger_lock);
722 
723 	if (kthread_should_stop())
724 		return false;
725 
726 	if (idr_is_empty(global_ft.idr))
727 		return false;
728 
729 	return true;
730 }
731 
732 static void ksmbd_scavenger_dispose_dh(struct list_head *head)
733 {
734 	while (!list_empty(head)) {
735 		struct ksmbd_file *fp;
736 
737 		fp = list_first_entry(head, struct ksmbd_file, node);
738 		list_del_init(&fp->node);
739 		__ksmbd_close_fd(NULL, fp);
740 	}
741 }
742 
743 static int ksmbd_durable_scavenger(void *dummy)
744 {
745 	struct ksmbd_file *fp = NULL;
746 	unsigned int id;
747 	unsigned int min_timeout = 1;
748 	bool found_fp_timeout;
749 	LIST_HEAD(scavenger_list);
750 	unsigned long remaining_jiffies;
751 
752 	__module_get(THIS_MODULE);
753 
754 	set_freezable();
755 	while (ksmbd_durable_scavenger_alive()) {
756 		if (try_to_freeze())
757 			continue;
758 
759 		found_fp_timeout = false;
760 
761 		remaining_jiffies = wait_event_timeout(dh_wq,
762 				   ksmbd_durable_scavenger_alive() == false,
763 				   __msecs_to_jiffies(min_timeout));
764 		if (remaining_jiffies)
765 			min_timeout = jiffies_to_msecs(remaining_jiffies);
766 		else
767 			min_timeout = DURABLE_HANDLE_MAX_TIMEOUT;
768 
769 		write_lock(&global_ft.lock);
770 		idr_for_each_entry(global_ft.idr, fp, id) {
771 			if (!fp->durable_timeout)
772 				continue;
773 
774 			if (atomic_read(&fp->refcount) > 1 ||
775 			    fp->conn)
776 				continue;
777 
778 			found_fp_timeout = true;
779 			if (fp->durable_scavenger_timeout <=
780 			    jiffies_to_msecs(jiffies)) {
781 				__ksmbd_remove_durable_fd(fp);
782 				list_add(&fp->node, &scavenger_list);
783 			} else {
784 				unsigned long durable_timeout;
785 
786 				durable_timeout =
787 					fp->durable_scavenger_timeout -
788 						jiffies_to_msecs(jiffies);
789 
790 				if (min_timeout > durable_timeout)
791 					min_timeout = durable_timeout;
792 			}
793 		}
794 		write_unlock(&global_ft.lock);
795 
796 		ksmbd_scavenger_dispose_dh(&scavenger_list);
797 
798 		if (found_fp_timeout == false)
799 			break;
800 	}
801 
802 	mutex_lock(&durable_scavenger_lock);
803 	durable_scavenger_running = false;
804 	mutex_unlock(&durable_scavenger_lock);
805 
806 	module_put(THIS_MODULE);
807 
808 	return 0;
809 }
810 
811 void ksmbd_launch_ksmbd_durable_scavenger(void)
812 {
813 	if (!(server_conf.flags & KSMBD_GLOBAL_FLAG_DURABLE_HANDLE))
814 		return;
815 
816 	mutex_lock(&durable_scavenger_lock);
817 	if (durable_scavenger_running == true) {
818 		mutex_unlock(&durable_scavenger_lock);
819 		return;
820 	}
821 
822 	durable_scavenger_running = true;
823 
824 	server_conf.dh_task = kthread_run(ksmbd_durable_scavenger,
825 				     (void *)NULL, "ksmbd-durable-scavenger");
826 	if (IS_ERR(server_conf.dh_task))
827 		pr_err("cannot start conn thread, err : %ld\n",
828 		       PTR_ERR(server_conf.dh_task));
829 	mutex_unlock(&durable_scavenger_lock);
830 }
831 
832 void ksmbd_stop_durable_scavenger(void)
833 {
834 	if (!(server_conf.flags & KSMBD_GLOBAL_FLAG_DURABLE_HANDLE))
835 		return;
836 
837 	mutex_lock(&durable_scavenger_lock);
838 	if (!durable_scavenger_running) {
839 		mutex_unlock(&durable_scavenger_lock);
840 		return;
841 	}
842 
843 	durable_scavenger_running = false;
844 	if (waitqueue_active(&dh_wq))
845 		wake_up(&dh_wq);
846 	mutex_unlock(&durable_scavenger_lock);
847 	kthread_stop(server_conf.dh_task);
848 }
849 
850 static bool session_fd_check(struct ksmbd_tree_connect *tcon,
851 			     struct ksmbd_file *fp)
852 {
853 	struct ksmbd_inode *ci;
854 	struct oplock_info *op;
855 	struct ksmbd_conn *conn;
856 
857 	if (!is_reconnectable(fp))
858 		return false;
859 
860 	conn = fp->conn;
861 	ci = fp->f_ci;
862 	down_write(&ci->m_lock);
863 	list_for_each_entry_rcu(op, &ci->m_op_list, op_entry) {
864 		if (op->conn != conn)
865 			continue;
866 		if (op->conn && atomic_dec_and_test(&op->conn->refcnt))
867 			kfree(op->conn);
868 		op->conn = NULL;
869 	}
870 	up_write(&ci->m_lock);
871 
872 	fp->conn = NULL;
873 	fp->tcon = NULL;
874 	fp->volatile_id = KSMBD_NO_FID;
875 
876 	if (fp->durable_timeout)
877 		fp->durable_scavenger_timeout =
878 			jiffies_to_msecs(jiffies) + fp->durable_timeout;
879 
880 	return true;
881 }
882 
883 void ksmbd_close_tree_conn_fds(struct ksmbd_work *work)
884 {
885 	int num = __close_file_table_ids(&work->sess->file_table,
886 					 work->tcon,
887 					 tree_conn_fd_check);
888 
889 	atomic_sub(num, &work->conn->stats.open_files_count);
890 }
891 
892 void ksmbd_close_session_fds(struct ksmbd_work *work)
893 {
894 	int num = __close_file_table_ids(&work->sess->file_table,
895 					 work->tcon,
896 					 session_fd_check);
897 
898 	atomic_sub(num, &work->conn->stats.open_files_count);
899 }
900 
901 int ksmbd_init_global_file_table(void)
902 {
903 	return ksmbd_init_file_table(&global_ft);
904 }
905 
906 void ksmbd_free_global_file_table(void)
907 {
908 	struct ksmbd_file	*fp = NULL;
909 	unsigned int		id;
910 
911 	idr_for_each_entry(global_ft.idr, fp, id) {
912 		ksmbd_remove_durable_fd(fp);
913 		__ksmbd_close_fd(NULL, fp);
914 	}
915 
916 	idr_destroy(global_ft.idr);
917 	kfree(global_ft.idr);
918 }
919 
920 int ksmbd_validate_name_reconnect(struct ksmbd_share_config *share,
921 				  struct ksmbd_file *fp, char *name)
922 {
923 	char *pathname, *ab_pathname;
924 	int ret = 0;
925 
926 	pathname = kmalloc(PATH_MAX, GFP_KERNEL);
927 	if (!pathname)
928 		return -EACCES;
929 
930 	ab_pathname = d_path(&fp->filp->f_path, pathname, PATH_MAX);
931 	if (IS_ERR(ab_pathname)) {
932 		kfree(pathname);
933 		return -EACCES;
934 	}
935 
936 	if (name && strcmp(&ab_pathname[share->path_sz + 1], name)) {
937 		ksmbd_debug(SMB, "invalid name reconnect %s\n", name);
938 		ret = -EINVAL;
939 	}
940 
941 	kfree(pathname);
942 
943 	return ret;
944 }
945 
946 int ksmbd_reopen_durable_fd(struct ksmbd_work *work, struct ksmbd_file *fp)
947 {
948 	struct ksmbd_inode *ci;
949 	struct oplock_info *op;
950 
951 	if (!fp->is_durable || fp->conn || fp->tcon) {
952 		pr_err("Invalid durable fd [%p:%p]\n", fp->conn, fp->tcon);
953 		return -EBADF;
954 	}
955 
956 	if (has_file_id(fp->volatile_id)) {
957 		pr_err("Still in use durable fd: %llu\n", fp->volatile_id);
958 		return -EBADF;
959 	}
960 
961 	fp->conn = work->conn;
962 	fp->tcon = work->tcon;
963 
964 	ci = fp->f_ci;
965 	down_write(&ci->m_lock);
966 	list_for_each_entry_rcu(op, &ci->m_op_list, op_entry) {
967 		if (op->conn)
968 			continue;
969 		op->conn = fp->conn;
970 		atomic_inc(&op->conn->refcnt);
971 	}
972 	up_write(&ci->m_lock);
973 
974 	fp->f_state = FP_NEW;
975 	__open_id(&work->sess->file_table, fp, OPEN_ID_TYPE_VOLATILE_ID);
976 	if (!has_file_id(fp->volatile_id)) {
977 		fp->conn = NULL;
978 		fp->tcon = NULL;
979 		return -EBADF;
980 	}
981 	return 0;
982 }
983 
984 int ksmbd_init_file_table(struct ksmbd_file_table *ft)
985 {
986 	ft->idr = kzalloc(sizeof(struct idr), GFP_KERNEL);
987 	if (!ft->idr)
988 		return -ENOMEM;
989 
990 	idr_init(ft->idr);
991 	rwlock_init(&ft->lock);
992 	return 0;
993 }
994 
995 void ksmbd_destroy_file_table(struct ksmbd_file_table *ft)
996 {
997 	if (!ft->idr)
998 		return;
999 
1000 	__close_file_table_ids(ft, NULL, session_fd_check);
1001 	idr_destroy(ft->idr);
1002 	kfree(ft->idr);
1003 	ft->idr = NULL;
1004 }
1005 
1006 int ksmbd_init_file_cache(void)
1007 {
1008 	filp_cache = kmem_cache_create("ksmbd_file_cache",
1009 				       sizeof(struct ksmbd_file), 0,
1010 				       SLAB_HWCACHE_ALIGN, NULL);
1011 	if (!filp_cache)
1012 		goto out;
1013 
1014 	init_waitqueue_head(&dh_wq);
1015 
1016 	return 0;
1017 
1018 out:
1019 	pr_err("failed to allocate file cache\n");
1020 	return -ENOMEM;
1021 }
1022 
1023 void ksmbd_exit_file_cache(void)
1024 {
1025 	kmem_cache_destroy(filp_cache);
1026 }
1027