cifs: check for NULL last_entry before calling cifs_save_resume_key
[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                 /* FIXME: check for inode number changes? */
90                 if (dentry->d_inode != NULL)
91                         return dentry;
92                 d_drop(dentry);
93                 dput(dentry);
94         }
95
96         dentry = d_alloc(parent, name);
97         if (dentry == NULL)
98                 return NULL;
99
100         inode = cifs_iget(sb, fattr);
101         if (!inode) {
102                 dput(dentry);
103                 return NULL;
104         }
105
106         alias = d_materialise_unique(dentry, inode);
107         if (alias != NULL) {
108                 dput(dentry);
109                 if (IS_ERR(alias))
110                         return NULL;
111                 dentry = alias;
112         }
113
114         return dentry;
115 }
116
117 static void
118 cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb)
119 {
120         fattr->cf_uid = cifs_sb->mnt_uid;
121         fattr->cf_gid = cifs_sb->mnt_gid;
122
123         if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
124                 fattr->cf_mode = S_IFDIR | cifs_sb->mnt_dir_mode;
125                 fattr->cf_dtype = DT_DIR;
126         } else {
127                 fattr->cf_mode = S_IFREG | cifs_sb->mnt_file_mode;
128                 fattr->cf_dtype = DT_REG;
129         }
130
131         if (fattr->cf_cifsattrs & ATTR_READONLY)
132                 fattr->cf_mode &= ~S_IWUGO;
133
134         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL &&
135             fattr->cf_cifsattrs & ATTR_SYSTEM) {
136                 if (fattr->cf_eof == 0)  {
137                         fattr->cf_mode &= ~S_IFMT;
138                         fattr->cf_mode |= S_IFIFO;
139                         fattr->cf_dtype = DT_FIFO;
140                 } else {
141                         /*
142                          * trying to get the type and mode via SFU can be slow,
143                          * so just call those regular files for now, and mark
144                          * for reval
145                          */
146                         fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
147                 }
148         }
149 }
150
151 static void
152 cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info,
153                        struct cifs_sb_info *cifs_sb)
154 {
155         memset(fattr, 0, sizeof(*fattr));
156         fattr->cf_cifsattrs = le32_to_cpu(info->ExtFileAttributes);
157         fattr->cf_eof = le64_to_cpu(info->EndOfFile);
158         fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
159         fattr->cf_createtime = le64_to_cpu(info->CreationTime);
160         fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
161         fattr->cf_ctime = cifs_NTtimeToUnix(info->ChangeTime);
162         fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);
163
164         cifs_fill_common_info(fattr, cifs_sb);
165 }
166
167 static void
168 cifs_std_info_to_fattr(struct cifs_fattr *fattr, FIND_FILE_STANDARD_INFO *info,
169                        struct cifs_sb_info *cifs_sb)
170 {
171         int offset = cifs_sb_master_tcon(cifs_sb)->ses->server->timeAdj;
172
173         memset(fattr, 0, sizeof(*fattr));
174         fattr->cf_atime = cnvrtDosUnixTm(info->LastAccessDate,
175                                             info->LastAccessTime, offset);
176         fattr->cf_ctime = cnvrtDosUnixTm(info->LastWriteDate,
177                                             info->LastWriteTime, offset);
178         fattr->cf_mtime = cnvrtDosUnixTm(info->LastWriteDate,
179                                             info->LastWriteTime, offset);
180
181         fattr->cf_cifsattrs = le16_to_cpu(info->Attributes);
182         fattr->cf_bytes = le32_to_cpu(info->AllocationSize);
183         fattr->cf_eof = le32_to_cpu(info->DataSize);
184
185         cifs_fill_common_info(fattr, cifs_sb);
186 }
187
188 /* BB eventually need to add the following helper function to
189       resolve NT_STATUS_STOPPED_ON_SYMLINK return code when
190       we try to do FindFirst on (NTFS) directory symlinks */
191 /*
192 int get_symlink_reparse_path(char *full_path, struct cifs_sb_info *cifs_sb,
193                              int xid)
194 {
195         __u16 fid;
196         int len;
197         int oplock = 0;
198         int rc;
199         struct cifs_tcon *ptcon = cifs_sb_tcon(cifs_sb);
200         char *tmpbuffer;
201
202         rc = CIFSSMBOpen(xid, ptcon, full_path, FILE_OPEN, GENERIC_READ,
203                         OPEN_REPARSE_POINT, &fid, &oplock, NULL,
204                         cifs_sb->local_nls,
205                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
206         if (!rc) {
207                 tmpbuffer = kmalloc(maxpath);
208                 rc = CIFSSMBQueryReparseLinkInfo(xid, ptcon, full_path,
209                                 tmpbuffer,
210                                 maxpath -1,
211                                 fid,
212                                 cifs_sb->local_nls);
213                 if (CIFSSMBClose(xid, ptcon, fid)) {
214                         cFYI(1, "Error closing temporary reparsepoint open");
215                 }
216         }
217 }
218  */
219
220 static int initiate_cifs_search(const int xid, struct file *file)
221 {
222         int rc = 0;
223         char *full_path = NULL;
224         struct cifsFileInfo *cifsFile;
225         struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
226         struct tcon_link *tlink = NULL;
227         struct cifs_tcon *pTcon;
228
229         if (file->private_data == NULL) {
230                 tlink = cifs_sb_tlink(cifs_sb);
231                 if (IS_ERR(tlink))
232                         return PTR_ERR(tlink);
233
234                 cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
235                 if (cifsFile == NULL) {
236                         rc = -ENOMEM;
237                         goto error_exit;
238                 }
239                 file->private_data = cifsFile;
240                 cifsFile->tlink = cifs_get_tlink(tlink);
241                 pTcon = tlink_tcon(tlink);
242         } else {
243                 cifsFile = file->private_data;
244                 pTcon = tlink_tcon(cifsFile->tlink);
245         }
246
247         cifsFile->invalidHandle = true;
248         cifsFile->srch_inf.endOfSearch = false;
249
250         full_path = build_path_from_dentry(file->f_path.dentry);
251         if (full_path == NULL) {
252                 rc = -ENOMEM;
253                 goto error_exit;
254         }
255
256         cFYI(1, "Full path: %s start at: %lld", full_path, file->f_pos);
257
258 ffirst_retry:
259         /* test for Unix extensions */
260         /* but now check for them on the share/mount not on the SMB session */
261 /*      if (pTcon->ses->capabilities & CAP_UNIX) { */
262         if (pTcon->unix_ext)
263                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
264         else if ((pTcon->ses->capabilities &
265                         (CAP_NT_SMBS | CAP_NT_FIND)) == 0) {
266                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD;
267         } else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
268                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
269         } else /* not srvinos - BB fixme add check for backlevel? */ {
270                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_DIRECTORY_INFO;
271         }
272
273         rc = CIFSFindFirst(xid, pTcon, full_path, cifs_sb->local_nls,
274                 &cifsFile->netfid, &cifsFile->srch_inf,
275                 cifs_sb->mnt_cifs_flags &
276                         CIFS_MOUNT_MAP_SPECIAL_CHR, CIFS_DIR_SEP(cifs_sb));
277         if (rc == 0)
278                 cifsFile->invalidHandle = false;
279         /* BB add following call to handle readdir on new NTFS symlink errors
280         else if STATUS_STOPPED_ON_SYMLINK
281                 call get_symlink_reparse_path and retry with new path */
282         else if ((rc == -EOPNOTSUPP) &&
283                 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
284                 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
285                 goto ffirst_retry;
286         }
287 error_exit:
288         kfree(full_path);
289         cifs_put_tlink(tlink);
290         return rc;
291 }
292
293 /* return length of unicode string in bytes */
294 static int cifs_unicode_bytelen(const char *str)
295 {
296         int len;
297         const __le16 *ustr = (const __le16 *)str;
298
299         for (len = 0; len <= PATH_MAX; len++) {
300                 if (ustr[len] == 0)
301                         return len << 1;
302         }
303         cFYI(1, "Unicode string longer than PATH_MAX found");
304         return len << 1;
305 }
306
307 static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
308 {
309         char *new_entry;
310         FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry;
311
312         if (level == SMB_FIND_FILE_INFO_STANDARD) {
313                 FIND_FILE_STANDARD_INFO *pfData;
314                 pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo;
315
316                 new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) +
317                                 pfData->FileNameLength;
318         } else
319                 new_entry = old_entry + le32_to_cpu(pDirInfo->NextEntryOffset);
320         cFYI(1, "new entry %p old entry %p", new_entry, old_entry);
321         /* validate that new_entry is not past end of SMB */
322         if (new_entry >= end_of_smb) {
323                 cERROR(1, "search entry %p began after end of SMB %p old entry %p",
324                         new_entry, end_of_smb, old_entry);
325                 return NULL;
326         } else if (((level == SMB_FIND_FILE_INFO_STANDARD) &&
327                     (new_entry + sizeof(FIND_FILE_STANDARD_INFO) > end_of_smb))
328                   || ((level != SMB_FIND_FILE_INFO_STANDARD) &&
329                    (new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb)))  {
330                 cERROR(1, "search entry %p extends after end of SMB %p",
331                         new_entry, end_of_smb);
332                 return NULL;
333         } else
334                 return new_entry;
335
336 }
337
338 struct cifs_dirent {
339         const char      *name;
340         size_t          namelen;
341         u32             resume_key;
342         u64             ino;
343 };
344
345 static void cifs_fill_dirent_unix(struct cifs_dirent *de,
346                 const FILE_UNIX_INFO *info, bool is_unicode)
347 {
348         de->name = &info->FileName[0];
349         if (is_unicode)
350                 de->namelen = cifs_unicode_bytelen(de->name);
351         else
352                 de->namelen = strnlen(de->name, PATH_MAX);
353         de->resume_key = info->ResumeKey;
354         de->ino = le64_to_cpu(info->basic.UniqueId);
355 }
356
357 static void cifs_fill_dirent_dir(struct cifs_dirent *de,
358                 const FILE_DIRECTORY_INFO *info)
359 {
360         de->name = &info->FileName[0];
361         de->namelen = le32_to_cpu(info->FileNameLength);
362         de->resume_key = info->FileIndex;
363 }
364
365 static void cifs_fill_dirent_full(struct cifs_dirent *de,
366                 const FILE_FULL_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_search(struct cifs_dirent *de,
374                 const SEARCH_ID_FULL_DIR_INFO *info)
375 {
376         de->name = &info->FileName[0];
377         de->namelen = le32_to_cpu(info->FileNameLength);
378         de->resume_key = info->FileIndex;
379         de->ino = le64_to_cpu(info->UniqueId);
380 }
381
382 static void cifs_fill_dirent_both(struct cifs_dirent *de,
383                 const FILE_BOTH_DIRECTORY_INFO *info)
384 {
385         de->name = &info->FileName[0];
386         de->namelen = le32_to_cpu(info->FileNameLength);
387         de->resume_key = info->FileIndex;
388 }
389
390 static void cifs_fill_dirent_std(struct cifs_dirent *de,
391                 const FIND_FILE_STANDARD_INFO *info)
392 {
393         de->name = &info->FileName[0];
394         /* one byte length, no endianess conversion */
395         de->namelen = info->FileNameLength;
396         de->resume_key = info->ResumeKey;
397 }
398
399 static int cifs_fill_dirent(struct cifs_dirent *de, const void *info,
400                 u16 level, bool is_unicode)
401 {
402         memset(de, 0, sizeof(*de));
403
404         switch (level) {
405         case SMB_FIND_FILE_UNIX:
406                 cifs_fill_dirent_unix(de, info, is_unicode);
407                 break;
408         case SMB_FIND_FILE_DIRECTORY_INFO:
409                 cifs_fill_dirent_dir(de, info);
410                 break;
411         case SMB_FIND_FILE_FULL_DIRECTORY_INFO:
412                 cifs_fill_dirent_full(de, info);
413                 break;
414         case SMB_FIND_FILE_ID_FULL_DIR_INFO:
415                 cifs_fill_dirent_search(de, info);
416                 break;
417         case SMB_FIND_FILE_BOTH_DIRECTORY_INFO:
418                 cifs_fill_dirent_both(de, info);
419                 break;
420         case SMB_FIND_FILE_INFO_STANDARD:
421                 cifs_fill_dirent_std(de, info);
422                 break;
423         default:
424                 cFYI(1, "Unknown findfirst level %d", level);
425                 return -EINVAL;
426         }
427
428         return 0;
429 }
430
431 #define UNICODE_DOT cpu_to_le16(0x2e)
432
433 /* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
434 static int cifs_entry_is_dot(struct cifs_dirent *de, bool is_unicode)
435 {
436         int rc = 0;
437
438         if (!de->name)
439                 return 0;
440
441         if (is_unicode) {
442                 __le16 *ufilename = (__le16 *)de->name;
443                 if (de->namelen == 2) {
444                         /* check for . */
445                         if (ufilename[0] == UNICODE_DOT)
446                                 rc = 1;
447                 } else if (de->namelen == 4) {
448                         /* check for .. */
449                         if (ufilename[0] == UNICODE_DOT &&
450                             ufilename[1] == UNICODE_DOT)
451                                 rc = 2;
452                 }
453         } else /* ASCII */ {
454                 if (de->namelen == 1) {
455                         if (de->name[0] == '.')
456                                 rc = 1;
457                 } else if (de->namelen == 2) {
458                         if (de->name[0] == '.' && de->name[1] == '.')
459                                 rc = 2;
460                 }
461         }
462
463         return rc;
464 }
465
466 /* Check if directory that we are searching has changed so we can decide
467    whether we can use the cached search results from the previous search */
468 static int is_dir_changed(struct file *file)
469 {
470         struct inode *inode = file->f_path.dentry->d_inode;
471         struct cifsInodeInfo *cifsInfo = CIFS_I(inode);
472
473         if (cifsInfo->time == 0)
474                 return 1; /* directory was changed, perhaps due to unlink */
475         else
476                 return 0;
477
478 }
479
480 static int cifs_save_resume_key(const char *current_entry,
481         struct cifsFileInfo *file_info)
482 {
483         struct cifs_dirent de;
484         int rc;
485
486         rc = cifs_fill_dirent(&de, current_entry, file_info->srch_inf.info_level,
487                               file_info->srch_inf.unicode);
488         if (!rc) {
489                 file_info->srch_inf.presume_name = de.name;
490                 file_info->srch_inf.resume_name_len = de.namelen;
491                 file_info->srch_inf.resume_key = de.resume_key;
492         }
493         return rc;
494 }
495
496 /* find the corresponding entry in the search */
497 /* Note that the SMB server returns search entries for . and .. which
498    complicates logic here if we choose to parse for them and we do not
499    assume that they are located in the findfirst return buffer.*/
500 /* We start counting in the buffer with entry 2 and increment for every
501    entry (do not increment for . or .. entry) */
502 static int find_cifs_entry(const int xid, struct cifs_tcon *pTcon,
503         struct file *file, char **ppCurrentEntry, int *num_to_ret)
504 {
505         int rc = 0;
506         int pos_in_buf = 0;
507         loff_t first_entry_in_buffer;
508         loff_t index_to_find = file->f_pos;
509         struct cifsFileInfo *cifsFile = file->private_data;
510         /* check if index in the buffer */
511
512         if ((cifsFile == NULL) || (ppCurrentEntry == NULL) ||
513            (num_to_ret == NULL))
514                 return -ENOENT;
515
516         *ppCurrentEntry = NULL;
517         first_entry_in_buffer =
518                 cifsFile->srch_inf.index_of_last_entry -
519                         cifsFile->srch_inf.entries_in_buffer;
520
521         /* if first entry in buf is zero then is first buffer
522         in search response data which means it is likely . and ..
523         will be in this buffer, although some servers do not return
524         . and .. for the root of a drive and for those we need
525         to start two entries earlier */
526
527         dump_cifs_file_struct(file, "In fce ");
528         if (((index_to_find < cifsFile->srch_inf.index_of_last_entry) &&
529              is_dir_changed(file)) ||
530            (index_to_find < first_entry_in_buffer)) {
531                 /* close and restart search */
532                 cFYI(1, "search backing up - close and restart search");
533                 spin_lock(&cifs_file_list_lock);
534                 if (!cifsFile->srch_inf.endOfSearch &&
535                     !cifsFile->invalidHandle) {
536                         cifsFile->invalidHandle = true;
537                         spin_unlock(&cifs_file_list_lock);
538                         CIFSFindClose(xid, pTcon, cifsFile->netfid);
539                 } else
540                         spin_unlock(&cifs_file_list_lock);
541                 if (cifsFile->srch_inf.ntwrk_buf_start) {
542                         cFYI(1, "freeing SMB ff cache buf on search rewind");
543                         if (cifsFile->srch_inf.smallBuf)
544                                 cifs_small_buf_release(cifsFile->srch_inf.
545                                                 ntwrk_buf_start);
546                         else
547                                 cifs_buf_release(cifsFile->srch_inf.
548                                                 ntwrk_buf_start);
549                         cifsFile->srch_inf.ntwrk_buf_start = NULL;
550                 }
551                 rc = initiate_cifs_search(xid, file);
552                 if (rc) {
553                         cFYI(1, "error %d reinitiating a search on rewind",
554                                  rc);
555                         return rc;
556                 }
557                 /* FindFirst/Next set last_entry to NULL on malformed reply */
558                 if (cifsFile->srch_inf.last_entry)
559                         cifs_save_resume_key(cifsFile->srch_inf.last_entry,
560                                                 cifsFile);
561         }
562
563         while ((index_to_find >= cifsFile->srch_inf.index_of_last_entry) &&
564               (rc == 0) && !cifsFile->srch_inf.endOfSearch) {
565                 cFYI(1, "calling findnext2");
566                 rc = CIFSFindNext(xid, pTcon, cifsFile->netfid,
567                                   &cifsFile->srch_inf);
568                 /* FindFirst/Next set last_entry to NULL on malformed reply */
569                 if (cifsFile->srch_inf.last_entry)
570                         cifs_save_resume_key(cifsFile->srch_inf.last_entry,
571                                                 cifsFile);
572                 if (rc)
573                         return -ENOENT;
574         }
575         if (index_to_find < cifsFile->srch_inf.index_of_last_entry) {
576                 /* we found the buffer that contains the entry */
577                 /* scan and find it */
578                 int i;
579                 char *current_entry;
580                 char *end_of_smb = cifsFile->srch_inf.ntwrk_buf_start +
581                         smbCalcSize((struct smb_hdr *)
582                                 cifsFile->srch_inf.ntwrk_buf_start);
583
584                 current_entry = cifsFile->srch_inf.srch_entries_start;
585                 first_entry_in_buffer = cifsFile->srch_inf.index_of_last_entry
586                                         - cifsFile->srch_inf.entries_in_buffer;
587                 pos_in_buf = index_to_find - first_entry_in_buffer;
588                 cFYI(1, "found entry - pos_in_buf %d", pos_in_buf);
589
590                 for (i = 0; (i < (pos_in_buf)) && (current_entry != NULL); i++) {
591                         /* go entry by entry figuring out which is first */
592                         current_entry = nxt_dir_entry(current_entry, end_of_smb,
593                                                 cifsFile->srch_inf.info_level);
594                 }
595                 if ((current_entry == NULL) && (i < pos_in_buf)) {
596                         /* BB fixme - check if we should flag this error */
597                         cERROR(1, "reached end of buf searching for pos in buf"
598                           " %d index to find %lld rc %d",
599                           pos_in_buf, index_to_find, rc);
600                 }
601                 rc = 0;
602                 *ppCurrentEntry = current_entry;
603         } else {
604                 cFYI(1, "index not in buffer - could not findnext into it");
605                 return 0;
606         }
607
608         if (pos_in_buf >= cifsFile->srch_inf.entries_in_buffer) {
609                 cFYI(1, "can not return entries pos_in_buf beyond last");
610                 *num_to_ret = 0;
611         } else
612                 *num_to_ret = cifsFile->srch_inf.entries_in_buffer - pos_in_buf;
613
614         return rc;
615 }
616
617 static int cifs_filldir(char *find_entry, struct file *file, filldir_t filldir,
618                 void *dirent, char *scratch_buf, unsigned int max_len)
619 {
620         struct cifsFileInfo *file_info = file->private_data;
621         struct super_block *sb = file->f_path.dentry->d_sb;
622         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
623         struct cifs_dirent de = { NULL, };
624         struct cifs_fattr fattr;
625         struct dentry *dentry;
626         struct qstr name;
627         int rc = 0;
628         ino_t ino;
629
630         rc = cifs_fill_dirent(&de, find_entry, file_info->srch_inf.info_level,
631                               file_info->srch_inf.unicode);
632         if (rc)
633                 return rc;
634
635         if (de.namelen > max_len) {
636                 cERROR(1, "bad search response length %zd past smb end",
637                           de.namelen);
638                 return -EINVAL;
639         }
640
641         /* skip . and .. since we added them first */
642         if (cifs_entry_is_dot(&de, file_info->srch_inf.unicode))
643                 return 0;
644
645         if (file_info->srch_inf.unicode) {
646                 struct nls_table *nlt = cifs_sb->local_nls;
647
648                 name.name = scratch_buf;
649                 name.len =
650                         cifs_from_ucs2((char *)name.name, (__le16 *)de.name,
651                                        UNICODE_NAME_MAX,
652                                        min(de.namelen, (size_t)max_len), nlt,
653                                        cifs_sb->mnt_cifs_flags &
654                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
655                 name.len -= nls_nullsize(nlt);
656         } else {
657                 name.name = de.name;
658                 name.len = de.namelen;
659         }
660
661         switch (file_info->srch_inf.info_level) {
662         case SMB_FIND_FILE_UNIX:
663                 cifs_unix_basic_to_fattr(&fattr,
664                                          &((FILE_UNIX_INFO *)find_entry)->basic,
665                                          cifs_sb);
666                 break;
667         case SMB_FIND_FILE_INFO_STANDARD:
668                 cifs_std_info_to_fattr(&fattr,
669                                        (FIND_FILE_STANDARD_INFO *)find_entry,
670                                        cifs_sb);
671                 break;
672         default:
673                 cifs_dir_info_to_fattr(&fattr,
674                                        (FILE_DIRECTORY_INFO *)find_entry,
675                                        cifs_sb);
676                 break;
677         }
678
679         if (de.ino && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
680                 fattr.cf_uniqueid = de.ino;
681         } else {
682                 fattr.cf_uniqueid = iunique(sb, ROOT_I);
683                 cifs_autodisable_serverino(cifs_sb);
684         }
685
686         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) &&
687             CIFSCouldBeMFSymlink(&fattr))
688                 /*
689                  * trying to get the type and mode can be slow,
690                  * so just call those regular files for now, and mark
691                  * for reval
692                  */
693                 fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
694
695         ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
696         dentry = cifs_readdir_lookup(file->f_dentry, &name, &fattr);
697
698         rc = filldir(dirent, name.name, name.len, file->f_pos, ino,
699                      fattr.cf_dtype);
700
701         dput(dentry);
702         return rc;
703 }
704
705
706 int cifs_readdir(struct file *file, void *direntry, filldir_t filldir)
707 {
708         int rc = 0;
709         int xid, i;
710         struct cifs_tcon *pTcon;
711         struct cifsFileInfo *cifsFile = NULL;
712         char *current_entry;
713         int num_to_fill = 0;
714         char *tmp_buf = NULL;
715         char *end_of_smb;
716         unsigned int max_len;
717
718         xid = GetXid();
719
720         /*
721          * Ensure FindFirst doesn't fail before doing filldir() for '.' and
722          * '..'. Otherwise we won't be able to notify VFS in case of failure.
723          */
724         if (file->private_data == NULL) {
725                 rc = initiate_cifs_search(xid, file);
726                 cFYI(1, "initiate cifs search rc %d", rc);
727                 if (rc)
728                         goto rddir2_exit;
729         }
730
731         switch ((int) file->f_pos) {
732         case 0:
733                 if (filldir(direntry, ".", 1, file->f_pos,
734                      file->f_path.dentry->d_inode->i_ino, DT_DIR) < 0) {
735                         cERROR(1, "Filldir for current dir failed");
736                         rc = -ENOMEM;
737                         break;
738                 }
739                 file->f_pos++;
740         case 1:
741                 if (filldir(direntry, "..", 2, file->f_pos,
742                      parent_ino(file->f_path.dentry), DT_DIR) < 0) {
743                         cERROR(1, "Filldir for parent dir failed");
744                         rc = -ENOMEM;
745                         break;
746                 }
747                 file->f_pos++;
748         default:
749                 /* 1) If search is active,
750                         is in current search buffer?
751                         if it before then restart search
752                         if after then keep searching till find it */
753
754                 if (file->private_data == NULL) {
755                         rc = -EINVAL;
756                         FreeXid(xid);
757                         return rc;
758                 }
759                 cifsFile = file->private_data;
760                 if (cifsFile->srch_inf.endOfSearch) {
761                         if (cifsFile->srch_inf.emptyDir) {
762                                 cFYI(1, "End of search, empty dir");
763                                 rc = 0;
764                                 break;
765                         }
766                 } /* else {
767                         cifsFile->invalidHandle = true;
768                         CIFSFindClose(xid, pTcon, cifsFile->netfid);
769                 } */
770
771                 pTcon = tlink_tcon(cifsFile->tlink);
772                 rc = find_cifs_entry(xid, pTcon, file,
773                                 &current_entry, &num_to_fill);
774                 if (rc) {
775                         cFYI(1, "fce error %d", rc);
776                         goto rddir2_exit;
777                 } else if (current_entry != NULL) {
778                         cFYI(1, "entry %lld found", file->f_pos);
779                 } else {
780                         cFYI(1, "could not find entry");
781                         goto rddir2_exit;
782                 }
783                 cFYI(1, "loop through %d times filling dir for net buf %p",
784                         num_to_fill, cifsFile->srch_inf.ntwrk_buf_start);
785                 max_len = smbCalcSize((struct smb_hdr *)
786                                 cifsFile->srch_inf.ntwrk_buf_start);
787                 end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len;
788
789                 tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL);
790                 if (tmp_buf == NULL) {
791                         rc = -ENOMEM;
792                         break;
793                 }
794
795                 for (i = 0; (i < num_to_fill) && (rc == 0); i++) {
796                         if (current_entry == NULL) {
797                                 /* evaluate whether this case is an error */
798                                 cERROR(1, "past SMB end,  num to fill %d i %d",
799                                           num_to_fill, i);
800                                 break;
801                         }
802                         /* if buggy server returns . and .. late do
803                         we want to check for that here? */
804                         rc = cifs_filldir(current_entry, file,
805                                         filldir, direntry, tmp_buf, max_len);
806                         if (rc == -EOVERFLOW) {
807                                 rc = 0;
808                                 break;
809                         }
810
811                         file->f_pos++;
812                         if (file->f_pos ==
813                                 cifsFile->srch_inf.index_of_last_entry) {
814                                 cFYI(1, "last entry in buf at pos %lld %s",
815                                         file->f_pos, tmp_buf);
816                                 cifs_save_resume_key(current_entry, cifsFile);
817                                 break;
818                         } else
819                                 current_entry =
820                                         nxt_dir_entry(current_entry, end_of_smb,
821                                                 cifsFile->srch_inf.info_level);
822                 }
823                 kfree(tmp_buf);
824                 break;
825         } /* end switch */
826
827 rddir2_exit:
828         FreeXid(xid);
829         return rc;
830 }