cifs: always update the inode cache with the results from a FIND_*
[linux-2.6.git] / fs / cifs / readdir.c
1 /*
2  *   fs/cifs/readdir.c
3  *
4  *   Directory search handling
5  *
6  *   Copyright (C) International Business Machines  Corp., 2004, 2008
7  *   Copyright (C) Red Hat, Inc., 2011
8  *   Author(s): Steve French (sfrench@us.ibm.com)
9  *
10  *   This library is free software; you can redistribute it and/or modify
11  *   it under the terms of the GNU Lesser General Public License as published
12  *   by the Free Software Foundation; either version 2.1 of the License, or
13  *   (at your option) any later version.
14  *
15  *   This library is distributed in the hope that it will be useful,
16  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
17  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
18  *   the GNU Lesser General Public License for more details.
19  *
20  *   You should have received a copy of the GNU Lesser General Public License
21  *   along with this library; if not, write to the Free Software
22  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23  */
24 #include <linux/fs.h>
25 #include <linux/pagemap.h>
26 #include <linux/slab.h>
27 #include <linux/stat.h>
28 #include "cifspdu.h"
29 #include "cifsglob.h"
30 #include "cifsproto.h"
31 #include "cifs_unicode.h"
32 #include "cifs_debug.h"
33 #include "cifs_fs_sb.h"
34 #include "cifsfs.h"
35
36 /*
37  * To be safe - for UCS to UTF-8 with strings loaded with the rare long
38  * characters alloc more to account for such multibyte target UTF-8
39  * characters.
40  */
41 #define UNICODE_NAME_MAX ((4 * NAME_MAX) + 2)
42
43 #ifdef CONFIG_CIFS_DEBUG2
44 static void dump_cifs_file_struct(struct file *file, char *label)
45 {
46         struct cifsFileInfo *cf;
47
48         if (file) {
49                 cf = file->private_data;
50                 if (cf == NULL) {
51                         cFYI(1, "empty cifs private file data");
52                         return;
53                 }
54                 if (cf->invalidHandle)
55                         cFYI(1, "invalid handle");
56                 if (cf->srch_inf.endOfSearch)
57                         cFYI(1, "end of search");
58                 if (cf->srch_inf.emptyDir)
59                         cFYI(1, "empty dir");
60         }
61 }
62 #else
63 static inline void dump_cifs_file_struct(struct file *file, char *label)
64 {
65 }
66 #endif /* DEBUG2 */
67
68 /*
69  * Find the dentry that matches "name". If there isn't one, create one. If it's
70  * a negative dentry or the uniqueid changed, then drop it and recreate it.
71  */
72 static struct dentry *
73 cifs_readdir_lookup(struct dentry *parent, struct qstr *name,
74                     struct cifs_fattr *fattr)
75 {
76         struct dentry *dentry, *alias;
77         struct inode *inode;
78         struct super_block *sb = parent->d_inode->i_sb;
79
80         cFYI(1, "For %s", name->name);
81
82         if (parent->d_op && parent->d_op->d_hash)
83                 parent->d_op->d_hash(parent, parent->d_inode, name);
84         else
85                 name->hash = full_name_hash(name->name, name->len);
86
87         dentry = d_lookup(parent, name);
88         if (dentry) {
89                 inode = dentry->d_inode;
90                 /* update inode in place if i_ino didn't change */
91                 if (inode && CIFS_I(inode)->uniqueid == fattr->cf_uniqueid) {
92                         cifs_fattr_to_inode(inode, fattr);
93                         return dentry;
94                 }
95                 d_drop(dentry);
96                 dput(dentry);
97         }
98
99         dentry = d_alloc(parent, name);
100         if (dentry == NULL)
101                 return NULL;
102
103         inode = cifs_iget(sb, fattr);
104         if (!inode) {
105                 dput(dentry);
106                 return NULL;
107         }
108
109         alias = d_materialise_unique(dentry, inode);
110         if (alias != NULL) {
111                 dput(dentry);
112                 if (IS_ERR(alias))
113                         return NULL;
114                 dentry = alias;
115         }
116
117         return dentry;
118 }
119
120 static void
121 cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb)
122 {
123         fattr->cf_uid = cifs_sb->mnt_uid;
124         fattr->cf_gid = cifs_sb->mnt_gid;
125
126         if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
127                 fattr->cf_mode = S_IFDIR | cifs_sb->mnt_dir_mode;
128                 fattr->cf_dtype = DT_DIR;
129         } else {
130                 fattr->cf_mode = S_IFREG | cifs_sb->mnt_file_mode;
131                 fattr->cf_dtype = DT_REG;
132         }
133
134         if (fattr->cf_cifsattrs & ATTR_READONLY)
135                 fattr->cf_mode &= ~S_IWUGO;
136
137         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL &&
138             fattr->cf_cifsattrs & ATTR_SYSTEM) {
139                 if (fattr->cf_eof == 0)  {
140                         fattr->cf_mode &= ~S_IFMT;
141                         fattr->cf_mode |= S_IFIFO;
142                         fattr->cf_dtype = DT_FIFO;
143                 } else {
144                         /*
145                          * trying to get the type and mode via SFU can be slow,
146                          * so just call those regular files for now, and mark
147                          * for reval
148                          */
149                         fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
150                 }
151         }
152 }
153
154 static void
155 cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info,
156                        struct cifs_sb_info *cifs_sb)
157 {
158         memset(fattr, 0, sizeof(*fattr));
159         fattr->cf_cifsattrs = le32_to_cpu(info->ExtFileAttributes);
160         fattr->cf_eof = le64_to_cpu(info->EndOfFile);
161         fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
162         fattr->cf_createtime = le64_to_cpu(info->CreationTime);
163         fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
164         fattr->cf_ctime = cifs_NTtimeToUnix(info->ChangeTime);
165         fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);
166
167         cifs_fill_common_info(fattr, cifs_sb);
168 }
169
170 static void
171 cifs_std_info_to_fattr(struct cifs_fattr *fattr, FIND_FILE_STANDARD_INFO *info,
172                        struct cifs_sb_info *cifs_sb)
173 {
174         int offset = cifs_sb_master_tcon(cifs_sb)->ses->server->timeAdj;
175
176         memset(fattr, 0, sizeof(*fattr));
177         fattr->cf_atime = cnvrtDosUnixTm(info->LastAccessDate,
178                                             info->LastAccessTime, offset);
179         fattr->cf_ctime = cnvrtDosUnixTm(info->LastWriteDate,
180                                             info->LastWriteTime, offset);
181         fattr->cf_mtime = cnvrtDosUnixTm(info->LastWriteDate,
182                                             info->LastWriteTime, offset);
183
184         fattr->cf_cifsattrs = le16_to_cpu(info->Attributes);
185         fattr->cf_bytes = le32_to_cpu(info->AllocationSize);
186         fattr->cf_eof = le32_to_cpu(info->DataSize);
187
188         cifs_fill_common_info(fattr, cifs_sb);
189 }
190
191 /* BB eventually need to add the following helper function to
192       resolve NT_STATUS_STOPPED_ON_SYMLINK return code when
193       we try to do FindFirst on (NTFS) directory symlinks */
194 /*
195 int get_symlink_reparse_path(char *full_path, struct cifs_sb_info *cifs_sb,
196                              int xid)
197 {
198         __u16 fid;
199         int len;
200         int oplock = 0;
201         int rc;
202         struct cifs_tcon *ptcon = cifs_sb_tcon(cifs_sb);
203         char *tmpbuffer;
204
205         rc = CIFSSMBOpen(xid, ptcon, full_path, FILE_OPEN, GENERIC_READ,
206                         OPEN_REPARSE_POINT, &fid, &oplock, NULL,
207                         cifs_sb->local_nls,
208                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
209         if (!rc) {
210                 tmpbuffer = kmalloc(maxpath);
211                 rc = CIFSSMBQueryReparseLinkInfo(xid, ptcon, full_path,
212                                 tmpbuffer,
213                                 maxpath -1,
214                                 fid,
215                                 cifs_sb->local_nls);
216                 if (CIFSSMBClose(xid, ptcon, fid)) {
217                         cFYI(1, "Error closing temporary reparsepoint open");
218                 }
219         }
220 }
221  */
222
223 static int initiate_cifs_search(const int xid, struct file *file)
224 {
225         __u16 search_flags;
226         int rc = 0;
227         char *full_path = NULL;
228         struct cifsFileInfo *cifsFile;
229         struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
230         struct tcon_link *tlink = NULL;
231         struct cifs_tcon *pTcon;
232
233         if (file->private_data == NULL) {
234                 tlink = cifs_sb_tlink(cifs_sb);
235                 if (IS_ERR(tlink))
236                         return PTR_ERR(tlink);
237
238                 cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
239                 if (cifsFile == NULL) {
240                         rc = -ENOMEM;
241                         goto error_exit;
242                 }
243                 file->private_data = cifsFile;
244                 cifsFile->tlink = cifs_get_tlink(tlink);
245                 pTcon = tlink_tcon(tlink);
246         } else {
247                 cifsFile = file->private_data;
248                 pTcon = tlink_tcon(cifsFile->tlink);
249         }
250
251         cifsFile->invalidHandle = true;
252         cifsFile->srch_inf.endOfSearch = false;
253
254         full_path = build_path_from_dentry(file->f_path.dentry);
255         if (full_path == NULL) {
256                 rc = -ENOMEM;
257                 goto error_exit;
258         }
259
260         cFYI(1, "Full path: %s start at: %lld", full_path, file->f_pos);
261
262 ffirst_retry:
263         /* test for Unix extensions */
264         /* but now check for them on the share/mount not on the SMB session */
265 /*      if (pTcon->ses->capabilities & CAP_UNIX) { */
266         if (pTcon->unix_ext)
267                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
268         else if ((pTcon->ses->capabilities &
269                         (CAP_NT_SMBS | CAP_NT_FIND)) == 0) {
270                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD;
271         } else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
272                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
273         } else /* not srvinos - BB fixme add check for backlevel? */ {
274                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_DIRECTORY_INFO;
275         }
276
277         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
278         if (backup_cred(cifs_sb))
279                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
280
281         rc = CIFSFindFirst(xid, pTcon, full_path, cifs_sb->local_nls,
282                 &cifsFile->netfid, search_flags, &cifsFile->srch_inf,
283                 cifs_sb->mnt_cifs_flags &
284                         CIFS_MOUNT_MAP_SPECIAL_CHR, CIFS_DIR_SEP(cifs_sb));
285         if (rc == 0)
286                 cifsFile->invalidHandle = false;
287         /* BB add following call to handle readdir on new NTFS symlink errors
288         else if STATUS_STOPPED_ON_SYMLINK
289                 call get_symlink_reparse_path and retry with new path */
290         else if ((rc == -EOPNOTSUPP) &&
291                 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
292                 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
293                 goto ffirst_retry;
294         }
295 error_exit:
296         kfree(full_path);
297         cifs_put_tlink(tlink);
298         return rc;
299 }
300
301 /* return length of unicode string in bytes */
302 static int cifs_unicode_bytelen(const char *str)
303 {
304         int len;
305         const __le16 *ustr = (const __le16 *)str;
306
307         for (len = 0; len <= PATH_MAX; len++) {
308                 if (ustr[len] == 0)
309                         return len << 1;
310         }
311         cFYI(1, "Unicode string longer than PATH_MAX found");
312         return len << 1;
313 }
314
315 static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
316 {
317         char *new_entry;
318         FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry;
319
320         if (level == SMB_FIND_FILE_INFO_STANDARD) {
321                 FIND_FILE_STANDARD_INFO *pfData;
322                 pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo;
323
324                 new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) +
325                                 pfData->FileNameLength;
326         } else
327                 new_entry = old_entry + le32_to_cpu(pDirInfo->NextEntryOffset);
328         cFYI(1, "new entry %p old entry %p", new_entry, old_entry);
329         /* validate that new_entry is not past end of SMB */
330         if (new_entry >= end_of_smb) {
331                 cERROR(1, "search entry %p began after end of SMB %p old entry %p",
332                         new_entry, end_of_smb, old_entry);
333                 return NULL;
334         } else if (((level == SMB_FIND_FILE_INFO_STANDARD) &&
335                     (new_entry + sizeof(FIND_FILE_STANDARD_INFO) > end_of_smb))
336                   || ((level != SMB_FIND_FILE_INFO_STANDARD) &&
337                    (new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb)))  {
338                 cERROR(1, "search entry %p extends after end of SMB %p",
339                         new_entry, end_of_smb);
340                 return NULL;
341         } else
342                 return new_entry;
343
344 }
345
346 struct cifs_dirent {
347         const char      *name;
348         size_t          namelen;
349         u32             resume_key;
350         u64             ino;
351 };
352
353 static void cifs_fill_dirent_unix(struct cifs_dirent *de,
354                 const FILE_UNIX_INFO *info, bool is_unicode)
355 {
356         de->name = &info->FileName[0];
357         if (is_unicode)
358                 de->namelen = cifs_unicode_bytelen(de->name);
359         else
360                 de->namelen = strnlen(de->name, PATH_MAX);
361         de->resume_key = info->ResumeKey;
362         de->ino = le64_to_cpu(info->basic.UniqueId);
363 }
364
365 static void cifs_fill_dirent_dir(struct cifs_dirent *de,
366                 const FILE_DIRECTORY_INFO *info)
367 {
368         de->name = &info->FileName[0];
369         de->namelen = le32_to_cpu(info->FileNameLength);
370         de->resume_key = info->FileIndex;
371 }
372
373 static void cifs_fill_dirent_full(struct cifs_dirent *de,
374                 const FILE_FULL_DIRECTORY_INFO *info)
375 {
376         de->name = &info->FileName[0];
377         de->namelen = le32_to_cpu(info->FileNameLength);
378         de->resume_key = info->FileIndex;
379 }
380
381 static void cifs_fill_dirent_search(struct cifs_dirent *de,
382                 const SEARCH_ID_FULL_DIR_INFO *info)
383 {
384         de->name = &info->FileName[0];
385         de->namelen = le32_to_cpu(info->FileNameLength);
386         de->resume_key = info->FileIndex;
387         de->ino = le64_to_cpu(info->UniqueId);
388 }
389
390 static void cifs_fill_dirent_both(struct cifs_dirent *de,
391                 const FILE_BOTH_DIRECTORY_INFO *info)
392 {
393         de->name = &info->FileName[0];
394         de->namelen = le32_to_cpu(info->FileNameLength);
395         de->resume_key = info->FileIndex;
396 }
397
398 static void cifs_fill_dirent_std(struct cifs_dirent *de,
399                 const FIND_FILE_STANDARD_INFO *info)
400 {
401         de->name = &info->FileName[0];
402         /* one byte length, no endianess conversion */
403         de->namelen = info->FileNameLength;
404         de->resume_key = info->ResumeKey;
405 }
406
407 static int cifs_fill_dirent(struct cifs_dirent *de, const void *info,
408                 u16 level, bool is_unicode)
409 {
410         memset(de, 0, sizeof(*de));
411
412         switch (level) {
413         case SMB_FIND_FILE_UNIX:
414                 cifs_fill_dirent_unix(de, info, is_unicode);
415                 break;
416         case SMB_FIND_FILE_DIRECTORY_INFO:
417                 cifs_fill_dirent_dir(de, info);
418                 break;
419         case SMB_FIND_FILE_FULL_DIRECTORY_INFO:
420                 cifs_fill_dirent_full(de, info);
421                 break;
422         case SMB_FIND_FILE_ID_FULL_DIR_INFO:
423                 cifs_fill_dirent_search(de, info);
424                 break;
425         case SMB_FIND_FILE_BOTH_DIRECTORY_INFO:
426                 cifs_fill_dirent_both(de, info);
427                 break;
428         case SMB_FIND_FILE_INFO_STANDARD:
429                 cifs_fill_dirent_std(de, info);
430                 break;
431         default:
432                 cFYI(1, "Unknown findfirst level %d", level);
433                 return -EINVAL;
434         }
435
436         return 0;
437 }
438
439 #define UNICODE_DOT cpu_to_le16(0x2e)
440
441 /* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
442 static int cifs_entry_is_dot(struct cifs_dirent *de, bool is_unicode)
443 {
444         int rc = 0;
445
446         if (!de->name)
447                 return 0;
448
449         if (is_unicode) {
450                 __le16 *ufilename = (__le16 *)de->name;
451                 if (de->namelen == 2) {
452                         /* check for . */
453                         if (ufilename[0] == UNICODE_DOT)
454                                 rc = 1;
455                 } else if (de->namelen == 4) {
456                         /* check for .. */
457                         if (ufilename[0] == UNICODE_DOT &&
458                             ufilename[1] == UNICODE_DOT)
459                                 rc = 2;
460                 }
461         } else /* ASCII */ {
462                 if (de->namelen == 1) {
463                         if (de->name[0] == '.')
464                                 rc = 1;
465                 } else if (de->namelen == 2) {
466                         if (de->name[0] == '.' && de->name[1] == '.')
467                                 rc = 2;
468                 }
469         }
470
471         return rc;
472 }
473
474 /* Check if directory that we are searching has changed so we can decide
475    whether we can use the cached search results from the previous search */
476 static int is_dir_changed(struct file *file)
477 {
478         struct inode *inode = file->f_path.dentry->d_inode;
479         struct cifsInodeInfo *cifsInfo = CIFS_I(inode);
480
481         if (cifsInfo->time == 0)
482                 return 1; /* directory was changed, perhaps due to unlink */
483         else
484                 return 0;
485
486 }
487
488 static int cifs_save_resume_key(const char *current_entry,
489         struct cifsFileInfo *file_info)
490 {
491         struct cifs_dirent de;
492         int rc;
493
494         rc = cifs_fill_dirent(&de, current_entry, file_info->srch_inf.info_level,
495                               file_info->srch_inf.unicode);
496         if (!rc) {
497                 file_info->srch_inf.presume_name = de.name;
498                 file_info->srch_inf.resume_name_len = de.namelen;
499                 file_info->srch_inf.resume_key = de.resume_key;
500         }
501         return rc;
502 }
503
504 /* find the corresponding entry in the search */
505 /* Note that the SMB server returns search entries for . and .. which
506    complicates logic here if we choose to parse for them and we do not
507    assume that they are located in the findfirst return buffer.*/
508 /* We start counting in the buffer with entry 2 and increment for every
509    entry (do not increment for . or .. entry) */
510 static int find_cifs_entry(const int xid, struct cifs_tcon *pTcon,
511         struct file *file, char **ppCurrentEntry, int *num_to_ret)
512 {
513         __u16 search_flags;
514         int rc = 0;
515         int pos_in_buf = 0;
516         loff_t first_entry_in_buffer;
517         loff_t index_to_find = file->f_pos;
518         struct cifsFileInfo *cifsFile = file->private_data;
519         struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
520         /* check if index in the buffer */
521
522         if ((cifsFile == NULL) || (ppCurrentEntry == NULL) ||
523            (num_to_ret == NULL))
524                 return -ENOENT;
525
526         *ppCurrentEntry = NULL;
527         first_entry_in_buffer =
528                 cifsFile->srch_inf.index_of_last_entry -
529                         cifsFile->srch_inf.entries_in_buffer;
530
531         /* if first entry in buf is zero then is first buffer
532         in search response data which means it is likely . and ..
533         will be in this buffer, although some servers do not return
534         . and .. for the root of a drive and for those we need
535         to start two entries earlier */
536
537         dump_cifs_file_struct(file, "In fce ");
538         if (((index_to_find < cifsFile->srch_inf.index_of_last_entry) &&
539              is_dir_changed(file)) ||
540            (index_to_find < first_entry_in_buffer)) {
541                 /* close and restart search */
542                 cFYI(1, "search backing up - close and restart search");
543                 spin_lock(&cifs_file_list_lock);
544                 if (!cifsFile->srch_inf.endOfSearch &&
545                     !cifsFile->invalidHandle) {
546                         cifsFile->invalidHandle = true;
547                         spin_unlock(&cifs_file_list_lock);
548                         CIFSFindClose(xid, pTcon, cifsFile->netfid);
549                 } else
550                         spin_unlock(&cifs_file_list_lock);
551                 if (cifsFile->srch_inf.ntwrk_buf_start) {
552                         cFYI(1, "freeing SMB ff cache buf on search rewind");
553                         if (cifsFile->srch_inf.smallBuf)
554                                 cifs_small_buf_release(cifsFile->srch_inf.
555                                                 ntwrk_buf_start);
556                         else
557                                 cifs_buf_release(cifsFile->srch_inf.
558                                                 ntwrk_buf_start);
559                         cifsFile->srch_inf.ntwrk_buf_start = NULL;
560                 }
561                 rc = initiate_cifs_search(xid, file);
562                 if (rc) {
563                         cFYI(1, "error %d reinitiating a search on rewind",
564                                  rc);
565                         return rc;
566                 }
567                 /* FindFirst/Next set last_entry to NULL on malformed reply */
568                 if (cifsFile->srch_inf.last_entry)
569                         cifs_save_resume_key(cifsFile->srch_inf.last_entry,
570                                                 cifsFile);
571         }
572
573         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
574         if (backup_cred(cifs_sb))
575                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
576
577         while ((index_to_find >= cifsFile->srch_inf.index_of_last_entry) &&
578               (rc == 0) && !cifsFile->srch_inf.endOfSearch) {
579                 cFYI(1, "calling findnext2");
580                 rc = CIFSFindNext(xid, pTcon, cifsFile->netfid, search_flags,
581                                   &cifsFile->srch_inf);
582                 /* FindFirst/Next set last_entry to NULL on malformed reply */
583                 if (cifsFile->srch_inf.last_entry)
584                         cifs_save_resume_key(cifsFile->srch_inf.last_entry,
585                                                 cifsFile);
586                 if (rc)
587                         return -ENOENT;
588         }
589         if (index_to_find < cifsFile->srch_inf.index_of_last_entry) {
590                 /* we found the buffer that contains the entry */
591                 /* scan and find it */
592                 int i;
593                 char *current_entry;
594                 char *end_of_smb = cifsFile->srch_inf.ntwrk_buf_start +
595                         smbCalcSize((struct smb_hdr *)
596                                 cifsFile->srch_inf.ntwrk_buf_start);
597
598                 current_entry = cifsFile->srch_inf.srch_entries_start;
599                 first_entry_in_buffer = cifsFile->srch_inf.index_of_last_entry
600                                         - cifsFile->srch_inf.entries_in_buffer;
601                 pos_in_buf = index_to_find - first_entry_in_buffer;
602                 cFYI(1, "found entry - pos_in_buf %d", pos_in_buf);
603
604                 for (i = 0; (i < (pos_in_buf)) && (current_entry != NULL); i++) {
605                         /* go entry by entry figuring out which is first */
606                         current_entry = nxt_dir_entry(current_entry, end_of_smb,
607                                                 cifsFile->srch_inf.info_level);
608                 }
609                 if ((current_entry == NULL) && (i < pos_in_buf)) {
610                         /* BB fixme - check if we should flag this error */
611                         cERROR(1, "reached end of buf searching for pos in buf"
612                           " %d index to find %lld rc %d",
613                           pos_in_buf, index_to_find, rc);
614                 }
615                 rc = 0;
616                 *ppCurrentEntry = current_entry;
617         } else {
618                 cFYI(1, "index not in buffer - could not findnext into it");
619                 return 0;
620         }
621
622         if (pos_in_buf >= cifsFile->srch_inf.entries_in_buffer) {
623                 cFYI(1, "can not return entries pos_in_buf beyond last");
624                 *num_to_ret = 0;
625         } else
626                 *num_to_ret = cifsFile->srch_inf.entries_in_buffer - pos_in_buf;
627
628         return rc;
629 }
630
631 static int cifs_filldir(char *find_entry, struct file *file, filldir_t filldir,
632                 void *dirent, char *scratch_buf, unsigned int max_len)
633 {
634         struct cifsFileInfo *file_info = file->private_data;
635         struct super_block *sb = file->f_path.dentry->d_sb;
636         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
637         struct cifs_dirent de = { NULL, };
638         struct cifs_fattr fattr;
639         struct dentry *dentry;
640         struct qstr name;
641         int rc = 0;
642         ino_t ino;
643
644         rc = cifs_fill_dirent(&de, find_entry, file_info->srch_inf.info_level,
645                               file_info->srch_inf.unicode);
646         if (rc)
647                 return rc;
648
649         if (de.namelen > max_len) {
650                 cERROR(1, "bad search response length %zd past smb end",
651                           de.namelen);
652                 return -EINVAL;
653         }
654
655         /* skip . and .. since we added them first */
656         if (cifs_entry_is_dot(&de, file_info->srch_inf.unicode))
657                 return 0;
658
659         if (file_info->srch_inf.unicode) {
660                 struct nls_table *nlt = cifs_sb->local_nls;
661
662                 name.name = scratch_buf;
663                 name.len =
664                         cifs_from_utf16((char *)name.name, (__le16 *)de.name,
665                                         UNICODE_NAME_MAX,
666                                         min_t(size_t, de.namelen,
667                                               (size_t)max_len), nlt,
668                                         cifs_sb->mnt_cifs_flags &
669                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
670                 name.len -= nls_nullsize(nlt);
671         } else {
672                 name.name = de.name;
673                 name.len = de.namelen;
674         }
675
676         switch (file_info->srch_inf.info_level) {
677         case SMB_FIND_FILE_UNIX:
678                 cifs_unix_basic_to_fattr(&fattr,
679                                          &((FILE_UNIX_INFO *)find_entry)->basic,
680                                          cifs_sb);
681                 break;
682         case SMB_FIND_FILE_INFO_STANDARD:
683                 cifs_std_info_to_fattr(&fattr,
684                                        (FIND_FILE_STANDARD_INFO *)find_entry,
685                                        cifs_sb);
686                 break;
687         default:
688                 cifs_dir_info_to_fattr(&fattr,
689                                        (FILE_DIRECTORY_INFO *)find_entry,
690                                        cifs_sb);
691                 break;
692         }
693
694         if (de.ino && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
695                 fattr.cf_uniqueid = de.ino;
696         } else {
697                 fattr.cf_uniqueid = iunique(sb, ROOT_I);
698                 cifs_autodisable_serverino(cifs_sb);
699         }
700
701         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) &&
702             CIFSCouldBeMFSymlink(&fattr))
703                 /*
704                  * trying to get the type and mode can be slow,
705                  * so just call those regular files for now, and mark
706                  * for reval
707                  */
708                 fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
709
710         ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
711         dentry = cifs_readdir_lookup(file->f_dentry, &name, &fattr);
712
713         rc = filldir(dirent, name.name, name.len, file->f_pos, ino,
714                      fattr.cf_dtype);
715
716         dput(dentry);
717         return rc;
718 }
719
720
721 int cifs_readdir(struct file *file, void *direntry, filldir_t filldir)
722 {
723         int rc = 0;
724         int xid, i;
725         struct cifs_tcon *pTcon;
726         struct cifsFileInfo *cifsFile = NULL;
727         char *current_entry;
728         int num_to_fill = 0;
729         char *tmp_buf = NULL;
730         char *end_of_smb;
731         unsigned int max_len;
732
733         xid = GetXid();
734
735         /*
736          * Ensure FindFirst doesn't fail before doing filldir() for '.' and
737          * '..'. Otherwise we won't be able to notify VFS in case of failure.
738          */
739         if (file->private_data == NULL) {
740                 rc = initiate_cifs_search(xid, file);
741                 cFYI(1, "initiate cifs search rc %d", rc);
742                 if (rc)
743                         goto rddir2_exit;
744         }
745
746         switch ((int) file->f_pos) {
747         case 0:
748                 if (filldir(direntry, ".", 1, file->f_pos,
749                      file->f_path.dentry->d_inode->i_ino, DT_DIR) < 0) {
750                         cERROR(1, "Filldir for current dir failed");
751                         rc = -ENOMEM;
752                         break;
753                 }
754                 file->f_pos++;
755         case 1:
756                 if (filldir(direntry, "..", 2, file->f_pos,
757                      parent_ino(file->f_path.dentry), DT_DIR) < 0) {
758                         cERROR(1, "Filldir for parent dir failed");
759                         rc = -ENOMEM;
760                         break;
761                 }
762                 file->f_pos++;
763         default:
764                 /* 1) If search is active,
765                         is in current search buffer?
766                         if it before then restart search
767                         if after then keep searching till find it */
768
769                 if (file->private_data == NULL) {
770                         rc = -EINVAL;
771                         FreeXid(xid);
772                         return rc;
773                 }
774                 cifsFile = file->private_data;
775                 if (cifsFile->srch_inf.endOfSearch) {
776                         if (cifsFile->srch_inf.emptyDir) {
777                                 cFYI(1, "End of search, empty dir");
778                                 rc = 0;
779                                 break;
780                         }
781                 } /* else {
782                         cifsFile->invalidHandle = true;
783                         CIFSFindClose(xid, pTcon, cifsFile->netfid);
784                 } */
785
786                 pTcon = tlink_tcon(cifsFile->tlink);
787                 rc = find_cifs_entry(xid, pTcon, file,
788                                 &current_entry, &num_to_fill);
789                 if (rc) {
790                         cFYI(1, "fce error %d", rc);
791                         goto rddir2_exit;
792                 } else if (current_entry != NULL) {
793                         cFYI(1, "entry %lld found", file->f_pos);
794                 } else {
795                         cFYI(1, "could not find entry");
796                         goto rddir2_exit;
797                 }
798                 cFYI(1, "loop through %d times filling dir for net buf %p",
799                         num_to_fill, cifsFile->srch_inf.ntwrk_buf_start);
800                 max_len = smbCalcSize((struct smb_hdr *)
801                                 cifsFile->srch_inf.ntwrk_buf_start);
802                 end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len;
803
804                 tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL);
805                 if (tmp_buf == NULL) {
806                         rc = -ENOMEM;
807                         break;
808                 }
809
810                 for (i = 0; (i < num_to_fill) && (rc == 0); i++) {
811                         if (current_entry == NULL) {
812                                 /* evaluate whether this case is an error */
813                                 cERROR(1, "past SMB end,  num to fill %d i %d",
814                                           num_to_fill, i);
815                                 break;
816                         }
817                         /* if buggy server returns . and .. late do
818                         we want to check for that here? */
819                         rc = cifs_filldir(current_entry, file,
820                                         filldir, direntry, tmp_buf, max_len);
821                         if (rc == -EOVERFLOW) {
822                                 rc = 0;
823                                 break;
824                         }
825
826                         file->f_pos++;
827                         if (file->f_pos ==
828                                 cifsFile->srch_inf.index_of_last_entry) {
829                                 cFYI(1, "last entry in buf at pos %lld %s",
830                                         file->f_pos, tmp_buf);
831                                 cifs_save_resume_key(current_entry, cifsFile);
832                                 break;
833                         } else
834                                 current_entry =
835                                         nxt_dir_entry(current_entry, end_of_smb,
836                                                 cifsFile->srch_inf.info_level);
837                 }
838                 kfree(tmp_buf);
839                 break;
840         } /* end switch */
841
842 rddir2_exit:
843         FreeXid(xid);
844         return rc;
845 }