summaryrefslogtreecommitdiff
path: root/fs/cifs/readdir.c
blob: d5e591fab4753bf48bde4e9d7883f1051d2dc280 (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
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
/*
 *   fs/cifs/readdir.c
 *
 *   Directory search handling
 *
 *   Copyright (C) International Business Machines  Corp., 2004, 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/fs.h>
#include <linux/pagemap.h>
#include <linux/slab.h>
#include <linux/stat.h>
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_unicode.h"
#include "cifs_debug.h"
#include "cifs_fs_sb.h"
#include "cifsfs.h"

/*
 * To be safe - for UCS to UTF-8 with strings loaded with the rare long
 * characters alloc more to account for such multibyte target UTF-8
 * characters.
 */
#define UNICODE_NAME_MAX ((4 * NAME_MAX) + 2)

#ifdef CONFIG_CIFS_DEBUG2
static void dump_cifs_file_struct(struct file *file, char *label)
{
	struct cifsFileInfo *cf;

	if (file) {
		cf = file->private_data;
		if (cf == NULL) {
			cFYI(1, "empty cifs private file data");
			return;
		}
		if (cf->invalidHandle)
			cFYI(1, "invalid handle");
		if (cf->srch_inf.endOfSearch)
			cFYI(1, "end of search");
		if (cf->srch_inf.emptyDir)
			cFYI(1, "empty dir");
	}
}
#else
static inline void dump_cifs_file_struct(struct file *file, char *label)
{
}
#endif /* DEBUG2 */

/*
 * Find the dentry that matches "name". If there isn't one, create one. If it's
 * a negative dentry or the uniqueid changed, then drop it and recreate it.
 */
static struct dentry *
cifs_readdir_lookup(struct dentry *parent, struct qstr *name,
		    struct cifs_fattr *fattr)
{
	struct dentry *dentry, *alias;
	struct inode *inode;
	struct super_block *sb = parent->d_inode->i_sb;

	cFYI(1, "For %s", name->name);

	if (parent->d_op && parent->d_op->d_hash)
		parent->d_op->d_hash(parent, name);
	else
		name->hash = full_name_hash(name->name, name->len);

	dentry = d_lookup(parent, name);
	if (dentry) {
		/* FIXME: check for inode number changes? */
		if (dentry->d_inode != NULL)
			return dentry;
		d_drop(dentry);
		dput(dentry);
	}

	dentry = d_alloc(parent, name);
	if (dentry == NULL)
		return NULL;

	inode = cifs_iget(sb, fattr);
	if (!inode) {
		dput(dentry);
		return NULL;
	}

	if (CIFS_SB(sb)->tcon->nocase)
		dentry->d_op = &cifs_ci_dentry_ops;
	else
		dentry->d_op = &cifs_dentry_ops;

	alias = d_materialise_unique(dentry, inode);
	if (alias != NULL) {
		dput(dentry);
		if (IS_ERR(alias))
			return NULL;
		dentry = alias;
	}

	return dentry;
}

static void
cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb)
{
	fattr->cf_uid = cifs_sb->mnt_uid;
	fattr->cf_gid = cifs_sb->mnt_gid;

	if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
		fattr->cf_mode = S_IFDIR | cifs_sb->mnt_dir_mode;
		fattr->cf_dtype = DT_DIR;
	} else {
		fattr->cf_mode = S_IFREG | cifs_sb->mnt_file_mode;
		fattr->cf_dtype = DT_REG;
	}

	if (fattr->cf_cifsattrs & ATTR_READONLY)
		fattr->cf_mode &= ~S_IWUGO;

	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL &&
	    fattr->cf_cifsattrs & ATTR_SYSTEM) {
		if (fattr->cf_eof == 0)  {
			fattr->cf_mode &= ~S_IFMT;
			fattr->cf_mode |= S_IFIFO;
			fattr->cf_dtype = DT_FIFO;
		} else {
			/*
			 * trying to get the type and mode via SFU can be slow,
			 * so just call those regular files for now, and mark
			 * for reval
			 */
			fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
		}
	}
}

static void
cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info,
		       struct cifs_sb_info *cifs_sb)
{
	memset(fattr, 0, sizeof(*fattr));
	fattr->cf_cifsattrs = le32_to_cpu(info->ExtFileAttributes);
	fattr->cf_eof = le64_to_cpu(info->EndOfFile);
	fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
	fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
	fattr->cf_ctime = cifs_NTtimeToUnix(info->ChangeTime);
	fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);

	cifs_fill_common_info(fattr, cifs_sb);
}

static void
cifs_std_info_to_fattr(struct cifs_fattr *fattr, FIND_FILE_STANDARD_INFO *info,
		       struct cifs_sb_info *cifs_sb)
{
	int offset = cifs_sb->tcon->ses->server->timeAdj;

	memset(fattr, 0, sizeof(*fattr));
	fattr->cf_atime = cnvrtDosUnixTm(info->LastAccessDate,
					    info->LastAccessTime, offset);
	fattr->cf_ctime = cnvrtDosUnixTm(info->LastWriteDate,
					    info->LastWriteTime, offset);
	fattr->cf_mtime = cnvrtDosUnixTm(info->LastWriteDate,
					    info->LastWriteTime, offset);

	fattr->cf_cifsattrs = le16_to_cpu(info->Attributes);
	fattr->cf_bytes = le32_to_cpu(info->AllocationSize);
	fattr->cf_eof = le32_to_cpu(info->DataSize);

	cifs_fill_common_info(fattr, cifs_sb);
}

/* BB eventually need to add the following helper function to
      resolve NT_STATUS_STOPPED_ON_SYMLINK return code when
      we try to do FindFirst on (NTFS) directory symlinks */
/*
int get_symlink_reparse_path(char *full_path, struct cifs_sb_info *cifs_sb,
			     int xid)
{
	__u16 fid;
	int len;
	int oplock = 0;
	int rc;
	struct cifsTconInfo *ptcon = cifs_sb->tcon;
	char *tmpbuffer;

	rc = CIFSSMBOpen(xid, ptcon, full_path, FILE_OPEN, GENERIC_READ,
			OPEN_REPARSE_POINT, &fid, &oplock, NULL,
			cifs_sb->local_nls,
			cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
	if (!rc) {
		tmpbuffer = kmalloc(maxpath);
		rc = CIFSSMBQueryReparseLinkInfo(xid, ptcon, full_path,
				tmpbuffer,
				maxpath -1,
				fid,
				cifs_sb->local_nls);
		if (CIFSSMBClose(xid, ptcon, fid)) {
			cFYI(1, "Error closing temporary reparsepoint open");
		}
	}
}
 */

static int initiate_cifs_search(const int xid, struct file *file)
{
	int rc = 0;
	char *full_path;
	struct cifsFileInfo *cifsFile;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;

	if (file->private_data == NULL) {
		file->private_data =
			kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
	}

	if (file->private_data == NULL)
		return -ENOMEM;
	cifsFile = file->private_data;
	cifsFile->invalidHandle = true;
	cifsFile->srch_inf.endOfSearch = false;

	cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
	if (cifs_sb == NULL)
		return -EINVAL;

	pTcon = cifs_sb->tcon;
	if (pTcon == NULL)
		return -EINVAL;

	full_path = build_path_from_dentry(file->f_path.dentry);

	if (full_path == NULL)
		return -ENOMEM;

	cFYI(1, "Full path: %s start at: %lld", full_path, file->f_pos);

ffirst_retry:
	/* test for Unix extensions */
	/* but now check for them on the share/mount not on the SMB session */
/*	if (pTcon->ses->capabilities & CAP_UNIX) { */
	if (pTcon->unix_ext)
		cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
	else if ((pTcon->ses->capabilities &
			(CAP_NT_SMBS | CAP_NT_FIND)) == 0) {
		cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD;
	} else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
		cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
	} else /* not srvinos - BB fixme add check for backlevel? */ {
		cifsFile->srch_inf.info_level = SMB_FIND_FILE_DIRECTORY_INFO;
	}

	rc = CIFSFindFirst(xid, pTcon, full_path, cifs_sb->local_nls,
		&cifsFile->netfid, &cifsFile->srch_inf,
		cifs_sb->mnt_cifs_flags &
			CIFS_MOUNT_MAP_SPECIAL_CHR, CIFS_DIR_SEP(cifs_sb));
	if (rc == 0)
		cifsFile->invalidHandle = false;
	/* BB add following call to handle readdir on new NTFS symlink errors
	else if STATUS_STOPPED_ON_SYMLINK
		call get_symlink_reparse_path and retry with new path */
	else if ((rc == -EOPNOTSUPP) &&
		(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
		goto ffirst_retry;
	}
	kfree(full_path);
	return rc;
}

/* return length of unicode string in bytes */
static int cifs_unicode_bytelen(char *str)
{
	int len;
	__le16 *ustr = (__le16 *)str;

	for (len = 0; len <= PATH_MAX; len++) {
		if (ustr[len] == 0)
			return len << 1;
	}
	cFYI(1, "Unicode string longer than PATH_MAX found");
	return len << 1;
}

static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
{
	char *new_entry;
	FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry;

	if (level == SMB_FIND_FILE_INFO_STANDARD) {
		FIND_FILE_STANDARD_INFO *pfData;
		pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo;

		new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) +
				pfData->FileNameLength;
	} else
		new_entry = old_entry + le32_to_cpu(pDirInfo->NextEntryOffset);
	cFYI(1, "new entry %p old entry %p", new_entry, old_entry);
	/* validate that new_entry is not past end of SMB */
	if (new_entry >= end_of_smb) {
		cERROR(1, "search entry %p began after end of SMB %p old entry %p",
			new_entry, end_of_smb, old_entry);
		return NULL;
	} else if (((level == SMB_FIND_FILE_INFO_STANDARD) &&
		    (new_entry + sizeof(FIND_FILE_STANDARD_INFO) > end_of_smb))
		  || ((level != SMB_FIND_FILE_INFO_STANDARD) &&
		   (new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb)))  {
		cERROR(1, "search entry %p extends after end of SMB %p",
			new_entry, end_of_smb);
		return NULL;
	} else
		return new_entry;

}

#define UNICODE_DOT cpu_to_le16(0x2e)

/* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
static int cifs_entry_is_dot(char *current_entry, struct cifsFileInfo *cfile)
{
	int rc = 0;
	char *filename = NULL;
	int len = 0;

	if (cfile->srch_inf.info_level == SMB_FIND_FILE_UNIX) {
		FILE_UNIX_INFO *pFindData = (FILE_UNIX_INFO *)current_entry;
		filename = &pFindData->FileName[0];
		if (cfile->srch_inf.unicode) {
			len = cifs_unicode_bytelen(filename);
		} else {
			/* BB should we make this strnlen of PATH_MAX? */
			len = strnlen(filename, 5);
		}
	} else if (cfile->srch_inf.info_level == SMB_FIND_FILE_DIRECTORY_INFO) {
		FILE_DIRECTORY_INFO *pFindData =
			(FILE_DIRECTORY_INFO *)current_entry;
		filename = &pFindData->FileName[0];
		len = le32_to_cpu(pFindData->FileNameLength);
	} else if (cfile->srch_inf.info_level ==
			SMB_FIND_FILE_FULL_DIRECTORY_INFO) {
		FILE_FULL_DIRECTORY_INFO *pFindData =
			(FILE_FULL_DIRECTORY_INFO *)current_entry;
		filename = &pFindData->FileName[0];
		len = le32_to_cpu(pFindData->FileNameLength);
	} else if (cfile->srch_inf.info_level ==
			SMB_FIND_FILE_ID_FULL_DIR_INFO) {
		SEARCH_ID_FULL_DIR_INFO *pFindData =
			(SEARCH_ID_FULL_DIR_INFO *)current_entry;
		filename = &pFindData->FileName[0];
		len = le32_to_cpu(pFindData->FileNameLength);
	} else if (cfile->srch_inf.info_level ==
			SMB_FIND_FILE_BOTH_DIRECTORY_INFO) {
		FILE_BOTH_DIRECTORY_INFO *pFindData =
			(FILE_BOTH_DIRECTORY_INFO *)current_entry;
		filename = &pFindData->FileName[0];
		len = le32_to_cpu(pFindData->FileNameLength);
	} else if (cfile->srch_inf.info_level == SMB_FIND_FILE_INFO_STANDARD) {
		FIND_FILE_STANDARD_INFO *pFindData =
			(FIND_FILE_STANDARD_INFO *)current_entry;
		filename = &pFindData->FileName[0];
		len = pFindData->FileNameLength;
	} else {
		cFYI(1, "Unknown findfirst level %d",
			 cfile->srch_inf.info_level);
	}

	if (filename) {
		if (cfile->srch_inf.unicode) {
			__le16 *ufilename = (__le16 *)filename;
			if (len == 2) {
				/* check for . */
				if (ufilename[0] == UNICODE_DOT)
					rc = 1;
			} else if (len == 4) {
				/* check for .. */
				if ((ufilename[0] == UNICODE_DOT)
				   && (ufilename[1] == UNICODE_DOT))
					rc = 2;
			}
		} else /* ASCII */ {
			if (len == 1) {
				if (filename[0] == '.')
					rc = 1;
			} else if (len == 2) {
				if ((filename[0] == '.') && (filename[1] == '.'))
					rc = 2;
			}
		}
	}

	return rc;
}

/* Check if directory that we are searching has changed so we can decide
   whether we can use the cached search results from the previous search */
static int is_dir_changed(struct file *file)
{
	struct inode *inode = file->f_path.dentry->d_inode;
	struct cifsInodeInfo *cifsInfo = CIFS_I(inode);

	if (cifsInfo->time == 0)
		return 1; /* directory was changed, perhaps due to unlink */
	else
		return 0;

}

static int cifs_save_resume_key(const char *current_entry,
	struct cifsFileInfo *cifsFile)
{
	int rc = 0;
	unsigned int len = 0;
	__u16 level;
	char *filename;

	if ((cifsFile == NULL) || (current_entry == NULL))
		return -EINVAL;

	level = cifsFile->srch_inf.info_level;

	if (level == SMB_FIND_FILE_UNIX) {
		FILE_UNIX_INFO *pFindData = (FILE_UNIX_INFO *)current_entry;

		filename = &pFindData->FileName[0];
		if (cifsFile->srch_inf.unicode) {
			len = cifs_unicode_bytelen(filename);
		} else {
			/* BB should we make this strnlen of PATH_MAX? */
			len = strnlen(filename, PATH_MAX);
		}
		cifsFile->srch_inf.resume_key = pFindData->ResumeKey;
	} else if (level == SMB_FIND_FILE_DIRECTORY_INFO) {
		FILE_DIRECTORY_INFO *pFindData =
			(FILE_DIRECTORY_INFO *)current_entry;
		filename = &pFindData->FileName[0];
		len = le32_to_cpu(pFindData->FileNameLength);
		cifsFile->srch_inf.resume_key = pFindData->FileIndex;
	} else if (level == SMB_FIND_FILE_FULL_DIRECTORY_INFO) {
		FILE_FULL_DIRECTORY_INFO *pFindData =
			(FILE_FULL_DIRECTORY_INFO *)current_entry;
		filename = &pFindData->FileName[0];
		len = le32_to_cpu(pFindData->FileNameLength);
		cifsFile->srch_inf.resume_key = pFindData->FileIndex;
	} else if (level == SMB_FIND_FILE_ID_FULL_DIR_INFO) {
		SEARCH_ID_FULL_DIR_INFO *pFindData =
			(SEARCH_ID_FULL_DIR_INFO *)current_entry;
		filename = &pFindData->FileName[0];
		len = le32_to_cpu(pFindData->FileNameLength);
		cifsFile->srch_inf.resume_key = pFindData->FileIndex;
	} else if (level == SMB_FIND_FILE_BOTH_DIRECTORY_INFO) {
		FILE_BOTH_DIRECTORY_INFO *pFindData =
			(FILE_BOTH_DIRECTORY_INFO *)current_entry;
		filename = &pFindData->FileName[0];
		len = le32_to_cpu(pFindData->FileNameLength);
		cifsFile->srch_inf.resume_key = pFindData->FileIndex;
	} else if (level == SMB_FIND_FILE_INFO_STANDARD) {
		FIND_FILE_STANDARD_INFO *pFindData =
			(FIND_FILE_STANDARD_INFO *)current_entry;
		filename = &pFindData->FileName[0];
		/* one byte length, no name conversion */
		len = (unsigned int)pFindData->FileNameLength;
		cifsFile->srch_inf.resume_key = pFindData->ResumeKey;
	} else {
		cFYI(1, "Unknown findfirst level %d", level);
		return -EINVAL;
	}
	cifsFile->srch_inf.resume_name_len = len;
	cifsFile->srch_inf.presume_name = filename;
	return rc;
}

/* find the corresponding entry in the search */
/* Note that the SMB server returns search entries for . and .. which
   complicates logic here if we choose to parse for them and we do not
   assume that they are located in the findfirst return buffer.*/
/* We start counting in the buffer with entry 2 and increment for every
   entry (do not increment for . or .. entry) */
static int find_cifs_entry(const int xid, struct cifsTconInfo *pTcon,
	struct file *file, char **ppCurrentEntry, int *num_to_ret)
{
	int rc = 0;
	int pos_in_buf = 0;
	loff_t first_entry_in_buffer;
	loff_t index_to_find = file->f_pos;
	struct cifsFileInfo *cifsFile = file->private_data;
	/* check if index in the buffer */

	if ((cifsFile == NULL) || (ppCurrentEntry == NULL) ||
	   (num_to_ret == NULL))
		return -ENOENT;

	*ppCurrentEntry = NULL;
	first_entry_in_buffer =
		cifsFile->srch_inf.index_of_last_entry -
			cifsFile->srch_inf.entries_in_buffer;

	/* if first entry in buf is zero then is first buffer
	in search response data which means it is likely . and ..
	will be in this buffer, although some servers do not return
	. and .. for the root of a drive and for those we need
	to start two entries earlier */

	dump_cifs_file_struct(file, "In fce ");
	if (((index_to_find < cifsFile->srch_inf.index_of_last_entry) &&
	     is_dir_changed(file)) ||
	   (index_to_find < first_entry_in_buffer)) {
		/* close and restart search */
		cFYI(1, "search backing up - close and restart search");
		write_lock(&GlobalSMBSeslock);
		if (!cifsFile->srch_inf.endOfSearch &&
		    !cifsFile->invalidHandle) {
			cifsFile->invalidHandle = true;
			write_unlock(&GlobalSMBSeslock);
			CIFSFindClose(xid, pTcon, cifsFile->netfid);
		} else
			write_unlock(&GlobalSMBSeslock);
		if (cifsFile->srch_inf.ntwrk_buf_start) {
			cFYI(1, "freeing SMB ff cache buf on search rewind");
			if (cifsFile->srch_inf.smallBuf)
				cifs_small_buf_release(cifsFile->srch_inf.
						ntwrk_buf_start);
			else
				cifs_buf_release(cifsFile->srch_inf.
						ntwrk_buf_start);
			cifsFile->srch_inf.ntwrk_buf_start = NULL;
		}
		rc = initiate_cifs_search(xid, file);
		if (rc) {
			cFYI(1, "error %d reinitiating a search on rewind",
				 rc);
			return rc;
		}
		cifs_save_resume_key(cifsFile->srch_inf.last_entry, cifsFile);
	}

	while ((index_to_find >= cifsFile->srch_inf.index_of_last_entry) &&
	      (rc == 0) && !cifsFile->srch_inf.endOfSearch) {
		cFYI(1, "calling findnext2");
		rc = CIFSFindNext(xid, pTcon, cifsFile->netfid,
				  &cifsFile->srch_inf);
		cifs_save_resume_key(cifsFile->srch_inf.last_entry, cifsFile);
		if (rc)
			return -ENOENT;
	}
	if (index_to_find < cifsFile->srch_inf.index_of_last_entry) {
		/* we found the buffer that contains the entry */
		/* scan and find it */
		int i;
		char *current_entry;
		char *end_of_smb = cifsFile->srch_inf.ntwrk_buf_start +
			smbCalcSize((struct smb_hdr *)
				cifsFile->srch_inf.ntwrk_buf_start);

		current_entry = cifsFile->srch_inf.srch_entries_start;
		first_entry_in_buffer = cifsFile->srch_inf.index_of_last_entry
					- cifsFile->srch_inf.entries_in_buffer;
		pos_in_buf = index_to_find - first_entry_in_buffer;
		cFYI(1, "found entry - pos_in_buf %d", pos_in_buf);

		for (i = 0; (i < (pos_in_buf)) && (current_entry != NULL); i++) {
			/* go entry by entry figuring out which is first */
			current_entry = nxt_dir_entry(current_entry, end_of_smb,
						cifsFile->srch_inf.info_level);
		}
		if ((current_entry == NULL) && (i < pos_in_buf)) {
			/* BB fixme - check if we should flag this error */
			cERROR(1, "reached end of buf searching for pos in buf"
			  " %d index to find %lld rc %d",
			  pos_in_buf, index_to_find, rc);
		}
		rc = 0;
		*ppCurrentEntry = current_entry;
	} else {
		cFYI(1, "index not in buffer - could not findnext into it");
		return 0;
	}

	if (pos_in_buf >= cifsFile->srch_inf.entries_in_buffer) {
		cFYI(1, "can not return entries pos_in_buf beyond last");
		*num_to_ret = 0;
	} else
		*num_to_ret = cifsFile->srch_inf.entries_in_buffer - pos_in_buf;

	return rc;
}

/* inode num, inode type and filename returned */
static int cifs_get_name_from_search_buf(struct qstr *pqst,
	char *current_entry, __u16 level, unsigned int unicode,
	struct cifs_sb_info *cifs_sb, unsigned int max_len, __u64 *pinum)
{
	int rc = 0;
	unsigned int len = 0;
	char *filename;
	struct nls_table *nlt = cifs_sb->local_nls;

	*pinum = 0;

	if (level == SMB_FIND_FILE_UNIX) {
		FILE_UNIX_INFO *pFindData = (FILE_UNIX_INFO *)current_entry;

		filename = &pFindData->FileName[0];
		if (unicode) {
			len = cifs_unicode_bytelen(filename);
		} else {
			/* BB should we make this strnlen of PATH_MAX? */
			len = strnlen(filename, PATH_MAX);
		}

		*pinum = le64_to_cpu(pFindData->basic.UniqueId);
	} else if (level == SMB_FIND_FILE_DIRECTORY_INFO) {
		FILE_DIRECTORY_INFO *pFindData =
			(FILE_DIRECTORY_INFO *)current_entry;
		filename = &pFindData->FileName[0];
		len = le32_to_cpu(pFindData->FileNameLength);
	} else if (level == SMB_FIND_FILE_FULL_DIRECTORY_INFO) {
		FILE_FULL_DIRECTORY_INFO *pFindData =
			(FILE_FULL_DIRECTORY_INFO *)current_entry;
		filename = &pFindData->FileName[0];
		len = le32_to_cpu(pFindData->FileNameLength);
	} else if (level == SMB_FIND_FILE_ID_FULL_DIR_INFO) {
		SEARCH_ID_FULL_DIR_INFO *pFindData =
			(SEARCH_ID_FULL_DIR_INFO *)current_entry;
		filename = &pFindData->FileName[0];
		len = le32_to_cpu(pFindData->FileNameLength);
		*pinum = le64_to_cpu(pFindData->UniqueId);
	} else if (level == SMB_FIND_FILE_BOTH_DIRECTORY_INFO) {
		FILE_BOTH_DIRECTORY_INFO *pFindData =
			(FILE_BOTH_DIRECTORY_INFO *)current_entry;
		filename = &pFindData->FileName[0];
		len = le32_to_cpu(pFindData->FileNameLength);
	} else if (level == SMB_FIND_FILE_INFO_STANDARD) {
		FIND_FILE_STANDARD_INFO *pFindData =
			(FIND_FILE_STANDARD_INFO *)current_entry;
		filename = &pFindData->FileName[0];
		/* one byte length, no name conversion */
		len = (unsigned int)pFindData->FileNameLength;
	} else {
		cFYI(1, "Unknown findfirst level %d", level);
		return -EINVAL;
	}

	if (len > max_len) {
		cERROR(1, "bad search response length %d past smb end", len);
		return -EINVAL;
	}

	if (unicode) {
		pqst->len = cifs_from_ucs2((char *) pqst->name,
					   (__le16 *) filename,
					   UNICODE_NAME_MAX,
					   min(len, max_len), nlt,
					   cifs_sb->mnt_cifs_flags &
						CIFS_MOUNT_MAP_SPECIAL_CHR);
		pqst->len -= nls_nullsize(nlt);
	} else {
		pqst->name = filename;
		pqst->len = len;
	}
	return rc;
}

static int cifs_filldir(char *pfindEntry, struct file *file, filldir_t filldir,
			void *direntry, char *scratch_buf, unsigned int max_len)
{
	int rc = 0;
	struct qstr qstring;
	struct cifsFileInfo *pCifsF;
	u64    inum;
	ino_t  ino;
	struct super_block *sb;
	struct cifs_sb_info *cifs_sb;
	struct dentry *tmp_dentry;
	struct cifs_fattr fattr;

	/* get filename and len into qstring */
	/* get dentry */
	/* decide whether to create and populate ionde */
	if ((direntry == NULL) || (file == NULL))
		return -EINVAL;

	pCifsF = file->private_data;

	if ((scratch_buf == NULL) || (pfindEntry == NULL) || (pCifsF == NULL))
		return -ENOENT;

	rc = cifs_entry_is_dot(pfindEntry, pCifsF);
	/* skip . and .. since we added them first */
	if (rc != 0)
		return 0;

	sb = file->f_path.dentry->d_sb;
	cifs_sb = CIFS_SB(sb);

	qstring.name = scratch_buf;
	rc = cifs_get_name_from_search_buf(&qstring, pfindEntry,
			pCifsF->srch_inf.info_level,
			pCifsF->srch_inf.unicode, cifs_sb,
			max_len, &inum /* returned */);

	if (rc)
		return rc;

	if (pCifsF->srch_inf.info_level == SMB_FIND_FILE_UNIX)
		cifs_unix_basic_to_fattr(&fattr,
				 &((FILE_UNIX_INFO *) pfindEntry)->basic,
				 cifs_sb);
	else if (pCifsF->srch_inf.info_level == SMB_FIND_FILE_INFO_STANDARD)
		cifs_std_info_to_fattr(&fattr, (FIND_FILE_STANDARD_INFO *)
					pfindEntry, cifs_sb);
	else
		cifs_dir_info_to_fattr(&fattr, (FILE_DIRECTORY_INFO *)
					pfindEntry, cifs_sb);

	if (inum && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
		fattr.cf_uniqueid = inum;
	} else {
		fattr.cf_uniqueid = iunique(sb, ROOT_I);
		cifs_autodisable_serverino(cifs_sb);
	}

	ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
	tmp_dentry = cifs_readdir_lookup(file->f_dentry, &qstring, &fattr);

	rc = filldir(direntry, qstring.name, qstring.len, file->f_pos,
		     ino, fattr.cf_dtype);

	/*
	 * we can not return filldir errors to the caller since they are
	 * "normal" when the stat blocksize is too small - we return remapped
	 * error instead
	 *
	 * FIXME: This looks bogus. filldir returns -EOVERFLOW in the above
	 * case already. Why should we be clobbering other errors from it?
	 */
	if (rc) {
		cFYI(1, "filldir rc = %d", rc);
		rc = -EOVERFLOW;
	}
	dput(tmp_dentry);
	return rc;
}


int cifs_readdir(struct file *file, void *direntry, filldir_t filldir)
{
	int rc = 0;
	int xid, i;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	struct cifsFileInfo *cifsFile = NULL;
	char *current_entry;
	int num_to_fill = 0;
	char *tmp_buf = NULL;
	char *end_of_smb;
	unsigned int max_len;

	xid = GetXid();

	cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
	pTcon = cifs_sb->tcon;
	if (pTcon == NULL)
		return -EINVAL;

	switch ((int) file->f_pos) {
	case 0:
		if (filldir(direntry, ".", 1, file->f_pos,
		     file->f_path.dentry->d_inode->i_ino, DT_DIR) < 0) {
			cERROR(1, "Filldir for current dir failed");
			rc = -ENOMEM;
			break;
		}
		file->f_pos++;
	case 1:
		if (filldir(direntry, "..", 2, file->f_pos,
		     file->f_path.dentry->d_parent->d_inode->i_ino, DT_DIR) < 0) {
			cERROR(1, "Filldir for parent dir failed");
			rc = -ENOMEM;
			break;
		}
		file->f_pos++;
	default:
		/* 1) If search is active,
			is in current search buffer?
			if it before then restart search
			if after then keep searching till find it */

		if (file->private_data == NULL) {
			rc = initiate_cifs_search(xid, file);
			cFYI(1, "initiate cifs search rc %d", rc);
			if (rc) {
				FreeXid(xid);
				return rc;
			}
		}
		if (file->private_data == NULL) {
			rc = -EINVAL;
			FreeXid(xid);
			return rc;
		}
		cifsFile = file->private_data;
		if (cifsFile->srch_inf.endOfSearch) {
			if (cifsFile->srch_inf.emptyDir) {
				cFYI(1, "End of search, empty dir");
				rc = 0;
				break;
			}
		} /* else {
			cifsFile->invalidHandle = true;
			CIFSFindClose(xid, pTcon, cifsFile->netfid);
		} */

		rc = find_cifs_entry(xid, pTcon, file,
				&current_entry, &num_to_fill);
		if (rc) {
			cFYI(1, "fce error %d", rc);
			goto rddir2_exit;
		} else if (current_entry != NULL) {
			cFYI(1, "entry %lld found", file->f_pos);
		} else {
			cFYI(1, "could not find entry");
			goto rddir2_exit;
		}
		cFYI(1, "loop through %d times filling dir for net buf %p",
			num_to_fill, cifsFile->srch_inf.ntwrk_buf_start);
		max_len = smbCalcSize((struct smb_hdr *)
				cifsFile->srch_inf.ntwrk_buf_start);
		end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len;

		tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL);
		if (tmp_buf == NULL) {
			rc = -ENOMEM;
			break;
		}

		for (i = 0; (i < num_to_fill) && (rc == 0); i++) {
			if (current_entry == NULL) {
				/* evaluate whether this case is an error */
				cERROR(1, "past SMB end,  num to fill %d i %d",
					  num_to_fill, i);
				break;
			}
			/* if buggy server returns . and .. late do
			we want to check for that here? */
			rc = cifs_filldir(current_entry, file,
					filldir, direntry, tmp_buf, max_len);
			if (rc == -EOVERFLOW) {
				rc = 0;
				break;
			}

			file->f_pos++;
			if (file->f_pos ==
				cifsFile->srch_inf.index_of_last_entry) {
				cFYI(1, "last entry in buf at pos %lld %s",
					file->f_pos, tmp_buf);
				cifs_save_resume_key(current_entry, cifsFile);
				break;
			} else
				current_entry =
					nxt_dir_entry(current_entry, end_of_smb,
						cifsFile->srch_inf.info_level);
		}
		kfree(tmp_buf);
		break;
	} /* end switch */

rddir2_exit:
	FreeXid(xid);
	return rc;
}