aboutsummaryrefslogtreecommitdiff
path: root/fs/cifs/misc.c
blob: c29d1aa2c54f30a76c25aa6ba843008b567ca96f (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
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
/*
 *   fs/cifs/misc.c
 *
 *   Copyright (C) International Business Machines  Corp., 2002,2008
 *   Author(s): Steve French (sfrench@us.ibm.com)
 *
 *   This library is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Lesser General Public License as published
 *   by the Free Software Foundation; either version 2.1 of the License, or
 *   (at your option) any later version.
 *
 *   This library is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *   the GNU Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with this library; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <linux/slab.h>
#include <linux/ctype.h>
#include <linux/mempool.h>
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_debug.h"
#include "smberr.h"
#include "nterr.h"
#include "cifs_unicode.h"

extern mempool_t *cifs_sm_req_poolp;
extern mempool_t *cifs_req_poolp;

/* The xid serves as a useful identifier for each incoming vfs request,
   in a similar way to the mid which is useful to track each sent smb,
   and CurrentXid can also provide a running counter (although it
   will eventually wrap past zero) of the total vfs operations handled
   since the cifs fs was mounted */

unsigned int
_GetXid(void)
{
	unsigned int xid;

	spin_lock(&GlobalMid_Lock);
	GlobalTotalActiveXid++;

	/* keep high water mark for number of simultaneous ops in filesystem */
	if (GlobalTotalActiveXid > GlobalMaxActiveXid)
		GlobalMaxActiveXid = GlobalTotalActiveXid;
	if (GlobalTotalActiveXid > 65000)
		cFYI(1, "warning: more than 65000 requests active");
	xid = GlobalCurrentXid++;
	spin_unlock(&GlobalMid_Lock);
	return xid;
}

void
_FreeXid(unsigned int xid)
{
	spin_lock(&GlobalMid_Lock);
	/* if (GlobalTotalActiveXid == 0)
		BUG(); */
	GlobalTotalActiveXid--;
	spin_unlock(&GlobalMid_Lock);
}

struct cifs_ses *
sesInfoAlloc(void)
{
	struct cifs_ses *ret_buf;

	ret_buf = kzalloc(sizeof(struct cifs_ses), GFP_KERNEL);
	if (ret_buf) {
		atomic_inc(&sesInfoAllocCount);
		ret_buf->status = CifsNew;
		++ret_buf->ses_count;
		INIT_LIST_HEAD(&ret_buf->smb_ses_list);
		INIT_LIST_HEAD(&ret_buf->tcon_list);
		mutex_init(&ret_buf->session_mutex);
	}
	return ret_buf;
}

void
sesInfoFree(struct cifs_ses *buf_to_free)
{
	if (buf_to_free == NULL) {
		cFYI(1, "Null buffer passed to sesInfoFree");
		return;
	}

	atomic_dec(&sesInfoAllocCount);
	kfree(buf_to_free->serverOS);
	kfree(buf_to_free->serverDomain);
	kfree(buf_to_free->serverNOS);
	if (buf_to_free->password) {
		memset(buf_to_free->password, 0, strlen(buf_to_free->password));
		kfree(buf_to_free->password);
	}
	kfree(buf_to_free->user_name);
	kfree(buf_to_free->domainName);
	kfree(buf_to_free);
}

struct cifs_tcon *
tconInfoAlloc(void)
{
	struct cifs_tcon *ret_buf;
	ret_buf = kzalloc(sizeof(struct cifs_tcon), GFP_KERNEL);
	if (ret_buf) {
		atomic_inc(&tconInfoAllocCount);
		ret_buf->tidStatus = CifsNew;
		++ret_buf->tc_count;
		INIT_LIST_HEAD(&ret_buf->openFileList);
		INIT_LIST_HEAD(&ret_buf->tcon_list);
#ifdef CONFIG_CIFS_STATS
		spin_lock_init(&ret_buf->stat_lock);
#endif
	}
	return ret_buf;
}

void
tconInfoFree(struct cifs_tcon *buf_to_free)
{
	if (buf_to_free == NULL) {
		cFYI(1, "Null buffer passed to tconInfoFree");
		return;
	}
	atomic_dec(&tconInfoAllocCount);
	kfree(buf_to_free->nativeFileSystem);
	if (buf_to_free->password) {
		memset(buf_to_free->password, 0, strlen(buf_to_free->password));
		kfree(buf_to_free->password);
	}
	kfree(buf_to_free);
}

struct smb_hdr *
cifs_buf_get(void)
{
	struct smb_hdr *ret_buf = NULL;

/* We could use negotiated size instead of max_msgsize -
   but it may be more efficient to always alloc same size
   albeit slightly larger than necessary and maxbuffersize
   defaults to this and can not be bigger */
	ret_buf = mempool_alloc(cifs_req_poolp, GFP_NOFS);

	/* clear the first few header bytes */
	/* for most paths, more is cleared in header_assemble */
	if (ret_buf) {
		memset(ret_buf, 0, sizeof(struct smb_hdr) + 3);
		atomic_inc(&bufAllocCount);
#ifdef CONFIG_CIFS_STATS2
		atomic_inc(&totBufAllocCount);
#endif /* CONFIG_CIFS_STATS2 */
	}

	return ret_buf;
}

void
cifs_buf_release(void *buf_to_free)
{
	if (buf_to_free == NULL) {
		/* cFYI(1, "Null buffer passed to cifs_buf_release");*/
		return;
	}
	mempool_free(buf_to_free, cifs_req_poolp);

	atomic_dec(&bufAllocCount);
	return;
}

struct smb_hdr *
cifs_small_buf_get(void)
{
	struct smb_hdr *ret_buf = NULL;

/* We could use negotiated size instead of max_msgsize -
   but it may be more efficient to always alloc same size
   albeit slightly larger than necessary and maxbuffersize
   defaults to this and can not be bigger */
	ret_buf = mempool_alloc(cifs_sm_req_poolp, GFP_NOFS);
	if (ret_buf) {
	/* No need to clear memory here, cleared in header assemble */
	/*	memset(ret_buf, 0, sizeof(struct smb_hdr) + 27);*/
		atomic_inc(&smBufAllocCount);
#ifdef CONFIG_CIFS_STATS2
		atomic_inc(&totSmBufAllocCount);
#endif /* CONFIG_CIFS_STATS2 */

	}
	return ret_buf;
}

void
cifs_small_buf_release(void *buf_to_free)
{

	if (buf_to_free == NULL) {
		cFYI(1, "Null buffer passed to cifs_small_buf_release");
		return;
	}
	mempool_free(buf_to_free, cifs_sm_req_poolp);

	atomic_dec(&smBufAllocCount);
	return;
}

/*
 * Find a free multiplex id (SMB mid). Otherwise there could be
 * mid collisions which might cause problems, demultiplexing the
 * wrong response to this request. Multiplex ids could collide if
 * one of a series requests takes much longer than the others, or
 * if a very large number of long lived requests (byte range
 * locks or FindNotify requests) are pending. No more than
 * 64K-1 requests can be outstanding at one time. If no
 * mids are available, return zero. A future optimization
 * could make the combination of mids and uid the key we use
 * to demultiplex on (rather than mid alone).
 * In addition to the above check, the cifs demultiplex
 * code already used the command code as a secondary
 * check of the frame and if signing is negotiated the
 * response would be discarded if the mid were the same
 * but the signature was wrong. Since the mid is not put in the
 * pending queue until later (when it is about to be dispatched)
 * we do have to limit the number of outstanding requests
 * to somewhat less than 64K-1 although it is hard to imagine
 * so many threads being in the vfs at one time.
 */
__u64 GetNextMid(struct TCP_Server_Info *server)
{
	__u64 mid = 0;
	__u16 last_mid, cur_mid;
	bool collision;

	spin_lock(&GlobalMid_Lock);

	/* mid is 16 bit only for CIFS/SMB */
	cur_mid = (__u16)((server->CurrentMid) & 0xffff);
	/* we do not want to loop forever */
	last_mid = cur_mid;
	cur_mid++;

	/*
	 * This nested loop looks more expensive than it is.
	 * In practice the list of pending requests is short,
	 * fewer than 50, and the mids are likely to be unique
	 * on the first pass through the loop unless some request
	 * takes longer than the 64 thousand requests before it
	 * (and it would also have to have been a request that
	 * did not time out).
	 */
	while (cur_mid != last_mid) {
		struct mid_q_entry *mid_entry;
		unsigned int num_mids;

		collision = false;
		if (cur_mid == 0)
			cur_mid++;

		num_mids = 0;
		list_for_each_entry(mid_entry, &server->pending_mid_q, qhead) {
			++num_mids;
			if (mid_entry->mid == cur_mid &&
			    mid_entry->mid_state == MID_REQUEST_SUBMITTED) {
				/* This mid is in use, try a different one */
				collision = true;
				break;
			}
		}

		/*
		 * if we have more than 32k mids in the list, then something
		 * is very wrong. Possibly a local user is trying to DoS the
		 * box by issuing long-running calls and SIGKILL'ing them. If
		 * we get to 2^16 mids then we're in big trouble as this
		 * function could loop forever.
		 *
		 * Go ahead and assign out the mid in this situation, but force
		 * an eventual reconnect to clean out the pending_mid_q.
		 */
		if (num_mids > 32768)
			server->tcpStatus = CifsNeedReconnect;

		if (!collision) {
			mid = (__u64)cur_mid;
			server->CurrentMid = mid;
			break;
		}
		cur_mid++;
	}
	spin_unlock(&GlobalMid_Lock);
	return mid;
}

/* NB: MID can not be set if treeCon not passed in, in that
   case it is responsbility of caller to set the mid */
void
header_assemble(struct smb_hdr *buffer, char smb_command /* command */ ,
		const struct cifs_tcon *treeCon, int word_count
		/* length of fixed section (word count) in two byte units  */)
{
	struct list_head *temp_item;
	struct cifs_ses *ses;
	char *temp = (char *) buffer;

	memset(temp, 0, 256); /* bigger than MAX_CIFS_HDR_SIZE */

	buffer->smb_buf_length = cpu_to_be32(
	    (2 * word_count) + sizeof(struct smb_hdr) -
	    4 /*  RFC 1001 length field does not count */  +
	    2 /* for bcc field itself */) ;

	buffer->Protocol[0] = 0xFF;
	buffer->Protocol[1] = 'S';
	buffer->Protocol[2] = 'M';
	buffer->Protocol[3] = 'B';
	buffer->Command = smb_command;
	buffer->Flags = 0x00;	/* case sensitive */
	buffer->Flags2 = SMBFLG2_KNOWS_LONG_NAMES;
	buffer->Pid = cpu_to_le16((__u16)current->tgid);
	buffer->PidHigh = cpu_to_le16((__u16)(current->tgid >> 16));
	if (treeCon) {
		buffer->Tid = treeCon->tid;
		if (treeCon->ses) {
			if (treeCon->ses->capabilities & CAP_UNICODE)
				buffer->Flags2 |= SMBFLG2_UNICODE;
			if (treeCon->ses->capabilities & CAP_STATUS32)
				buffer->Flags2 |= SMBFLG2_ERR_STATUS;

			/* Uid is not converted */
			buffer->Uid = treeCon->ses->Suid;
			buffer->Mid = GetNextMid(treeCon->ses->server);
			if (multiuser_mount != 0) {
		/* For the multiuser case, there are few obvious technically  */
		/* possible mechanisms to match the local linux user (uid)    */
		/* to a valid remote smb user (smb_uid):		      */
		/* 	1) Query Winbind (or other local pam/nss daemon       */
		/* 	  for userid/password/logon_domain or credential      */
		/*      2) Query Winbind for uid to sid to username mapping   */
		/* 	   and see if we have a matching password for existing*/
		/*         session for that user perhas getting password by   */
		/*         adding a new pam_cifs module that stores passwords */
		/*         so that the cifs vfs can get at that for all logged*/
		/*	   on users					      */
		/*	3) (Which is the mechanism we have chosen)	      */
		/*	   Search through sessions to the same server for a   */
		/*	   a match on the uid that was passed in on mount     */
		/*         with the current processes uid (or euid?) and use  */
		/* 	   that smb uid.   If no existing smb session for     */
		/* 	   that uid found, use the default smb session ie     */
		/*         the smb session for the volume mounted which is    */
		/* 	   the same as would be used if the multiuser mount   */
		/* 	   flag were disabled.  */

		/*  BB Add support for establishing new tCon and SMB Session  */
		/*      with userid/password pairs found on the smb session   */
		/*	for other target tcp/ip addresses 		BB    */
				if (current_fsuid() != treeCon->ses->linux_uid) {
					cFYI(1, "Multiuser mode and UID "
						 "did not match tcon uid");
					spin_lock(&cifs_tcp_ses_lock);
					list_for_each(temp_item, &treeCon->ses->server->smb_ses_list) {
						ses = list_entry(temp_item, struct cifs_ses, smb_ses_list);
						if (ses->linux_uid == current_fsuid()) {
							if (ses->server == treeCon->ses->server) {
								cFYI(1, "found matching uid substitute right smb_uid");
								buffer->Uid = ses->Suid;
								break;
							} else {
				/* BB eventually call cifs_setup_session here */
								cFYI(1, "local UID found but no smb sess with this server exists");
							}
						}
					}
					spin_unlock(&cifs_tcp_ses_lock);
				}
			}
		}
		if (treeCon->Flags & SMB_SHARE_IS_IN_DFS)
			buffer->Flags2 |= SMBFLG2_DFS;
		if (treeCon->nocase)
			buffer->Flags  |= SMBFLG_CASELESS;
		if ((treeCon->ses) && (treeCon->ses->server))
			if (treeCon->ses->server->sec_mode &
			  (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
				buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
	}

/*  endian conversion of flags is now done just before sending */
	buffer->WordCount = (char) word_count;
	return;
}

static int
check_smb_hdr(struct smb_hdr *smb, __u16 mid)
{
	/* does it have the right SMB "signature" ? */
	if (*(__le32 *) smb->Protocol != cpu_to_le32(0x424d53ff)) {
		cERROR(1, "Bad protocol string signature header 0x%x",
			*(unsigned int *)smb->Protocol);
		return 1;
	}

	/* Make sure that message ids match */
	if (mid != smb->Mid) {
		cERROR(1, "Mids do not match. received=%u expected=%u",
			smb->Mid, mid);
		return 1;
	}

	/* if it's a response then accept */
	if (smb->Flags & SMBFLG_RESPONSE)
		return 0;

	/* only one valid case where server sends us request */
	if (smb->Command == SMB_COM_LOCKING_ANDX)
		return 0;

	cERROR(1, "Server sent request, not response. mid=%u", smb->Mid);
	return 1;
}

int
checkSMB(char *buf, unsigned int total_read)
{
	struct smb_hdr *smb = (struct smb_hdr *)buf;
	__u16 mid = smb->Mid;
	__u32 rfclen = be32_to_cpu(smb->smb_buf_length);
	__u32 clc_len;  /* calculated length */
	cFYI(0, "checkSMB Length: 0x%x, smb_buf_length: 0x%x",
		total_read, rfclen);

	/* is this frame too small to even get to a BCC? */
	if (total_read < 2 + sizeof(struct smb_hdr)) {
		if ((total_read >= sizeof(struct smb_hdr) - 1)
			    && (smb->Status.CifsError != 0)) {
			/* it's an error return */
			smb->WordCount = 0;
			/* some error cases do not return wct and bcc */
			return 0;
		} else if ((total_read == sizeof(struct smb_hdr) + 1) &&
				(smb->WordCount == 0)) {
			char *tmp = (char *)smb;
			/* Need to work around a bug in two servers here */
			/* First, check if the part of bcc they sent was zero */
			if (tmp[sizeof(struct smb_hdr)] == 0) {
				/* some servers return only half of bcc
				 * on simple responses (wct, bcc both zero)
				 * in particular have seen this on
				 * ulogoffX and FindClose. This leaves
				 * one byte of bcc potentially unitialized
				 */
				/* zero rest of bcc */
				tmp[sizeof(struct smb_hdr)+1] = 0;
				return 0;
			}
			cERROR(1, "rcvd invalid byte count (bcc)");
		} else {
			cERROR(1, "Length less than smb header size");
		}
		return -EIO;
	}

	/* otherwise, there is enough to get to the BCC */
	if (check_smb_hdr(smb, mid))
		return -EIO;
	clc_len = smbCalcSize(smb);

	if (4 + rfclen != total_read) {
		cERROR(1, "Length read does not match RFC1001 length %d",
				rfclen);
		return -EIO;
	}

	if (4 + rfclen != clc_len) {
		/* check if bcc wrapped around for large read responses */
		if ((rfclen > 64 * 1024) && (rfclen > clc_len)) {
			/* check if lengths match mod 64K */
			if (((4 + rfclen) & 0xFFFF) == (clc_len & 0xFFFF))
				return 0; /* bcc wrapped */
		}
		cFYI(1, "Calculated size %u vs length %u mismatch for mid=%u",
				clc_len, 4 + rfclen, smb->Mid);

		if (4 + rfclen < clc_len) {
			cERROR(1, "RFC1001 size %u smaller than SMB for mid=%u",
					rfclen, smb->Mid);
			return -EIO;
		} else if (rfclen > clc_len + 512) {
			/*
			 * Some servers (Windows XP in particular) send more
			 * data than the lengths in the SMB packet would
			 * indicate on certain calls (byte range locks and
			 * trans2 find first calls in particular). While the
			 * client can handle such a frame by ignoring the
			 * trailing data, we choose limit the amount of extra
			 * data to 512 bytes.
			 */
			cERROR(1, "RFC1001 size %u more than 512 bytes larger "
				  "than SMB for mid=%u", rfclen, smb->Mid);
			return -EIO;
		}
	}
	return 0;
}

bool
is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv)
{
	struct smb_hdr *buf = (struct smb_hdr *)buffer;
	struct smb_com_lock_req *pSMB = (struct smb_com_lock_req *)buf;
	struct list_head *tmp, *tmp1, *tmp2;
	struct cifs_ses *ses;
	struct cifs_tcon *tcon;
	struct cifsInodeInfo *pCifsInode;
	struct cifsFileInfo *netfile;

	cFYI(1, "Checking for oplock break or dnotify response");
	if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) &&
	   (pSMB->hdr.Flags & SMBFLG_RESPONSE)) {
		struct smb_com_transaction_change_notify_rsp *pSMBr =
			(struct smb_com_transaction_change_notify_rsp *)buf;
		struct file_notify_information *pnotify;
		__u32 data_offset = 0;
		if (get_bcc(buf) > sizeof(struct file_notify_information)) {
			data_offset = le32_to_cpu(pSMBr->DataOffset);

			pnotify = (struct file_notify_information *)
				((char *)&pSMBr->hdr.Protocol + data_offset);
			cFYI(1, "dnotify on %s Action: 0x%x",
				 pnotify->FileName, pnotify->Action);
			/*   cifs_dump_mem("Rcvd notify Data: ",buf,
				sizeof(struct smb_hdr)+60); */
			return true;
		}
		if (pSMBr->hdr.Status.CifsError) {
			cFYI(1, "notify err 0x%d",
				pSMBr->hdr.Status.CifsError);
			return true;
		}
		return false;
	}
	if (pSMB->hdr.Command != SMB_COM_LOCKING_ANDX)
		return false;
	if (pSMB->hdr.Flags & SMBFLG_RESPONSE) {
		/* no sense logging error on invalid handle on oplock
		   break - harmless race between close request and oplock
		   break response is expected from time to time writing out
		   large dirty files cached on the client */
		if ((NT_STATUS_INVALID_HANDLE) ==
		   le32_to_cpu(pSMB->hdr.Status.CifsError)) {
			cFYI(1, "invalid handle on oplock break");
			return true;
		} else if (ERRbadfid ==
		   le16_to_cpu(pSMB->hdr.Status.DosError.Error)) {
			return true;
		} else {
			return false; /* on valid oplock brk we get "request" */
		}
	}
	if (pSMB->hdr.WordCount != 8)
		return false;

	cFYI(1, "oplock type 0x%d level 0x%d",
		 pSMB->LockType, pSMB->OplockLevel);
	if (!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE))
		return false;

	/* look up tcon based on tid & uid */
	spin_lock(&cifs_tcp_ses_lock);
	list_for_each(tmp, &srv->smb_ses_list) {
		ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
		list_for_each(tmp1, &ses->tcon_list) {
			tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
			if (tcon->tid != buf->Tid)
				continue;

			cifs_stats_inc(&tcon->num_oplock_brks);
			spin_lock(&cifs_file_list_lock);
			list_for_each(tmp2, &tcon->openFileList) {
				netfile = list_entry(tmp2, struct cifsFileInfo,
						     tlist);
				if (pSMB->Fid != netfile->netfid)
					continue;

				cFYI(1, "file id match, oplock break");
				pCifsInode = CIFS_I(netfile->dentry->d_inode);

				cifs_set_oplock_level(pCifsInode,
					pSMB->OplockLevel ? OPLOCK_READ : 0);
				queue_work(cifsiod_wq,
					   &netfile->oplock_break);
				netfile->oplock_break_cancelled = false;

				spin_unlock(&cifs_file_list_lock);
				spin_unlock(&cifs_tcp_ses_lock);
				return true;
			}
			spin_unlock(&cifs_file_list_lock);
			spin_unlock(&cifs_tcp_ses_lock);
			cFYI(1, "No matching file for oplock break");
			return true;
		}
	}
	spin_unlock(&cifs_tcp_ses_lock);
	cFYI(1, "Can not process oplock break for non-existent connection");
	return true;
}

void
dump_smb(void *buf, int smb_buf_length)
{
	int i, j;
	char debug_line[17];
	unsigned char *buffer = buf;

	if (traceSMB == 0)
		return;

	for (i = 0, j = 0; i < smb_buf_length; i++, j++) {
		if (i % 8 == 0) {
			/* have reached the beginning of line */
			printk(KERN_DEBUG "| ");
			j = 0;
		}
		printk("%0#4x ", buffer[i]);
		debug_line[2 * j] = ' ';
		if (isprint(buffer[i]))
			debug_line[1 + (2 * j)] = buffer[i];
		else
			debug_line[1 + (2 * j)] = '_';

		if (i % 8 == 7) {
			/* reached end of line, time to print ascii */
			debug_line[16] = 0;
			printk(" | %s\n", debug_line);
		}
	}
	for (; j < 8; j++) {
		printk("     ");
		debug_line[2 * j] = ' ';
		debug_line[1 + (2 * j)] = ' ';
	}
	printk(" | %s\n", debug_line);
	return;
}

void
cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb)
{
	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
		cERROR(1, "Autodisabling the use of server inode numbers on "
			   "%s. This server doesn't seem to support them "
			   "properly. Hardlinks will not be recognized on this "
			   "mount. Consider mounting with the \"noserverino\" "
			   "option to silence this message.",
			   cifs_sb_master_tcon(cifs_sb)->treeName);
	}
}

void cifs_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock)
{
	oplock &= 0xF;

	if (oplock == OPLOCK_EXCLUSIVE) {
		cinode->clientCanCacheAll = true;
		cinode->clientCanCacheRead = true;
		cFYI(1, "Exclusive Oplock granted on inode %p",
		     &cinode->vfs_inode);
	} else if (oplock == OPLOCK_READ) {
		cinode->clientCanCacheAll = false;
		cinode->clientCanCacheRead = true;
		cFYI(1, "Level II Oplock granted on inode %p",
		    &cinode->vfs_inode);
	} else {
		cinode->clientCanCacheAll = false;
		cinode->clientCanCacheRead = false;
	}
}

bool
backup_cred(struct cifs_sb_info *cifs_sb)
{
	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID) {
		if (cifs_sb->mnt_backupuid == current_fsuid())
			return true;
	}
	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID) {
		if (in_group_p(cifs_sb->mnt_backupgid))
			return true;
	}

	return false;
}

void
cifs_add_credits(struct TCP_Server_Info *server, const unsigned int add)
{
	spin_lock(&server->req_lock);
	server->credits += add;
	server->in_flight--;
	spin_unlock(&server->req_lock);
	wake_up(&server->request_q);
}

void
cifs_set_credits(struct TCP_Server_Info *server, const int val)
{
	spin_lock(&server->req_lock);
	server->credits = val;
	server->oplocks = val > 1 ? enable_oplocks : false;
	spin_unlock(&server->req_lock);
}