fix "disabling echoes and oplocks" on SMB2 mounts
[linux-3.10.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  * Attempt to preload the dcache with the results from the FIND_FIRST/NEXT
70  *
71  * Find the dentry that matches "name". If there isn't one, create one. If it's
72  * a negative dentry or the uniqueid changed, then drop it and recreate it.
73  */
74 static void
75 cifs_prime_dcache(struct dentry *parent, struct qstr *name,
76                     struct cifs_fattr *fattr)
77 {
78         struct dentry *dentry, *alias;
79         struct inode *inode;
80         struct super_block *sb = parent->d_inode->i_sb;
81
82         cFYI(1, "%s: for %s", __func__, name->name);
83
84         if (parent->d_op && parent->d_op->d_hash)
85                 parent->d_op->d_hash(parent, parent->d_inode, name);
86         else
87                 name->hash = full_name_hash(name->name, name->len);
88
89         dentry = d_lookup(parent, name);
90         if (dentry) {
91                 int err;
92
93                 inode = dentry->d_inode;
94                 /* update inode in place if i_ino didn't change */
95                 if (inode && CIFS_I(inode)->uniqueid == fattr->cf_uniqueid) {
96                         cifs_fattr_to_inode(inode, fattr);
97                         goto out;
98                 }
99                 err = d_invalidate(dentry);
100                 dput(dentry);
101                 if (err)
102                         return;
103         }
104
105         dentry = d_alloc(parent, name);
106         if (!dentry)
107                 return;
108
109         inode = cifs_iget(sb, fattr);
110         if (!inode)
111                 goto out;
112
113         alias = d_materialise_unique(dentry, inode);
114         if (alias && !IS_ERR(alias))
115                 dput(alias);
116 out:
117         dput(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         /*
138          * We of course don't get ACL info in FIND_FIRST/NEXT results, so
139          * mark it for revalidation so that "ls -l" will look right. It might
140          * be super-slow, but if we don't do this then the ownership of files
141          * may look wrong since the inodes may not have timed out by the time
142          * "ls" does a stat() call on them.
143          */
144         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL)
145                 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
146
147         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL &&
148             fattr->cf_cifsattrs & ATTR_SYSTEM) {
149                 if (fattr->cf_eof == 0)  {
150                         fattr->cf_mode &= ~S_IFMT;
151                         fattr->cf_mode |= S_IFIFO;
152                         fattr->cf_dtype = DT_FIFO;
153                 } else {
154                         /*
155                          * trying to get the type and mode via SFU can be slow,
156                          * so just call those regular files for now, and mark
157                          * for reval
158                          */
159                         fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
160                 }
161         }
162 }
163
164 void
165 cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info,
166                        struct cifs_sb_info *cifs_sb)
167 {
168         memset(fattr, 0, sizeof(*fattr));
169         fattr->cf_cifsattrs = le32_to_cpu(info->ExtFileAttributes);
170         fattr->cf_eof = le64_to_cpu(info->EndOfFile);
171         fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
172         fattr->cf_createtime = le64_to_cpu(info->CreationTime);
173         fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
174         fattr->cf_ctime = cifs_NTtimeToUnix(info->ChangeTime);
175         fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);
176
177         cifs_fill_common_info(fattr, cifs_sb);
178 }
179
180 static void
181 cifs_std_info_to_fattr(struct cifs_fattr *fattr, FIND_FILE_STANDARD_INFO *info,
182                        struct cifs_sb_info *cifs_sb)
183 {
184         int offset = cifs_sb_master_tcon(cifs_sb)->ses->server->timeAdj;
185
186         memset(fattr, 0, sizeof(*fattr));
187         fattr->cf_atime = cnvrtDosUnixTm(info->LastAccessDate,
188                                             info->LastAccessTime, offset);
189         fattr->cf_ctime = cnvrtDosUnixTm(info->LastWriteDate,
190                                             info->LastWriteTime, offset);
191         fattr->cf_mtime = cnvrtDosUnixTm(info->LastWriteDate,
192                                             info->LastWriteTime, offset);
193
194         fattr->cf_cifsattrs = le16_to_cpu(info->Attributes);
195         fattr->cf_bytes = le32_to_cpu(info->AllocationSize);
196         fattr->cf_eof = le32_to_cpu(info->DataSize);
197
198         cifs_fill_common_info(fattr, cifs_sb);
199 }
200
201 /* BB eventually need to add the following helper function to
202       resolve NT_STATUS_STOPPED_ON_SYMLINK return code when
203       we try to do FindFirst on (NTFS) directory symlinks */
204 /*
205 int get_symlink_reparse_path(char *full_path, struct cifs_sb_info *cifs_sb,
206                              unsigned int xid)
207 {
208         __u16 fid;
209         int len;
210         int oplock = 0;
211         int rc;
212         struct cifs_tcon *ptcon = cifs_sb_tcon(cifs_sb);
213         char *tmpbuffer;
214
215         rc = CIFSSMBOpen(xid, ptcon, full_path, FILE_OPEN, GENERIC_READ,
216                         OPEN_REPARSE_POINT, &fid, &oplock, NULL,
217                         cifs_sb->local_nls,
218                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
219         if (!rc) {
220                 tmpbuffer = kmalloc(maxpath);
221                 rc = CIFSSMBQueryReparseLinkInfo(xid, ptcon, full_path,
222                                 tmpbuffer,
223                                 maxpath -1,
224                                 fid,
225                                 cifs_sb->local_nls);
226                 if (CIFSSMBClose(xid, ptcon, fid)) {
227                         cFYI(1, "Error closing temporary reparsepoint open");
228                 }
229         }
230 }
231  */
232
233 static int
234 initiate_cifs_search(const unsigned int xid, struct file *file)
235 {
236         __u16 search_flags;
237         int rc = 0;
238         char *full_path = NULL;
239         struct cifsFileInfo *cifsFile;
240         struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
241         struct tcon_link *tlink = NULL;
242         struct cifs_tcon *tcon;
243         struct TCP_Server_Info *server;
244
245         if (file->private_data == NULL) {
246                 tlink = cifs_sb_tlink(cifs_sb);
247                 if (IS_ERR(tlink))
248                         return PTR_ERR(tlink);
249
250                 cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
251                 if (cifsFile == NULL) {
252                         rc = -ENOMEM;
253                         goto error_exit;
254                 }
255                 file->private_data = cifsFile;
256                 cifsFile->tlink = cifs_get_tlink(tlink);
257                 tcon = tlink_tcon(tlink);
258         } else {
259                 cifsFile = file->private_data;
260                 tcon = tlink_tcon(cifsFile->tlink);
261         }
262
263         server = tcon->ses->server;
264
265         if (!server->ops->query_dir_first) {
266                 rc = -ENOSYS;
267                 goto error_exit;
268         }
269
270         cifsFile->invalidHandle = true;
271         cifsFile->srch_inf.endOfSearch = false;
272
273         full_path = build_path_from_dentry(file->f_path.dentry);
274         if (full_path == NULL) {
275                 rc = -ENOMEM;
276                 goto error_exit;
277         }
278
279         cFYI(1, "Full path: %s start at: %lld", full_path, file->f_pos);
280
281 ffirst_retry:
282         /* test for Unix extensions */
283         /* but now check for them on the share/mount not on the SMB session */
284         /* if (cap_unix(tcon->ses) { */
285         if (tcon->unix_ext)
286                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
287         else if ((tcon->ses->capabilities &
288                   tcon->ses->server->vals->cap_nt_find) == 0) {
289                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD;
290         } else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
291                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
292         } else /* not srvinos - BB fixme add check for backlevel? */ {
293                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_DIRECTORY_INFO;
294         }
295
296         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
297         if (backup_cred(cifs_sb))
298                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
299
300         rc = server->ops->query_dir_first(xid, tcon, full_path, cifs_sb,
301                                           &cifsFile->fid, search_flags,
302                                           &cifsFile->srch_inf);
303
304         if (rc == 0)
305                 cifsFile->invalidHandle = false;
306         /* BB add following call to handle readdir on new NTFS symlink errors
307         else if STATUS_STOPPED_ON_SYMLINK
308                 call get_symlink_reparse_path and retry with new path */
309         else if ((rc == -EOPNOTSUPP) &&
310                 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
311                 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
312                 goto ffirst_retry;
313         }
314 error_exit:
315         kfree(full_path);
316         cifs_put_tlink(tlink);
317         return rc;
318 }
319
320 /* return length of unicode string in bytes */
321 static int cifs_unicode_bytelen(const char *str)
322 {
323         int len;
324         const __le16 *ustr = (const __le16 *)str;
325
326         for (len = 0; len <= PATH_MAX; len++) {
327                 if (ustr[len] == 0)
328                         return len << 1;
329         }
330         cFYI(1, "Unicode string longer than PATH_MAX found");
331         return len << 1;
332 }
333
334 static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
335 {
336         char *new_entry;
337         FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry;
338
339         if (level == SMB_FIND_FILE_INFO_STANDARD) {
340                 FIND_FILE_STANDARD_INFO *pfData;
341                 pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo;
342
343                 new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) +
344                                 pfData->FileNameLength;
345         } else
346                 new_entry = old_entry + le32_to_cpu(pDirInfo->NextEntryOffset);
347         cFYI(1, "new entry %p old entry %p", new_entry, old_entry);
348         /* validate that new_entry is not past end of SMB */
349         if (new_entry >= end_of_smb) {
350                 cERROR(1, "search entry %p began after end of SMB %p old entry %p",
351                         new_entry, end_of_smb, old_entry);
352                 return NULL;
353         } else if (((level == SMB_FIND_FILE_INFO_STANDARD) &&
354                     (new_entry + sizeof(FIND_FILE_STANDARD_INFO) > end_of_smb))
355                   || ((level != SMB_FIND_FILE_INFO_STANDARD) &&
356                    (new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb)))  {
357                 cERROR(1, "search entry %p extends after end of SMB %p",
358                         new_entry, end_of_smb);
359                 return NULL;
360         } else
361                 return new_entry;
362
363 }
364
365 struct cifs_dirent {
366         const char      *name;
367         size_t          namelen;
368         u32             resume_key;
369         u64             ino;
370 };
371
372 static void cifs_fill_dirent_unix(struct cifs_dirent *de,
373                 const FILE_UNIX_INFO *info, bool is_unicode)
374 {
375         de->name = &info->FileName[0];
376         if (is_unicode)
377                 de->namelen = cifs_unicode_bytelen(de->name);
378         else
379                 de->namelen = strnlen(de->name, PATH_MAX);
380         de->resume_key = info->ResumeKey;
381         de->ino = le64_to_cpu(info->basic.UniqueId);
382 }
383
384 static void cifs_fill_dirent_dir(struct cifs_dirent *de,
385                 const FILE_DIRECTORY_INFO *info)
386 {
387         de->name = &info->FileName[0];
388         de->namelen = le32_to_cpu(info->FileNameLength);
389         de->resume_key = info->FileIndex;
390 }
391
392 static void cifs_fill_dirent_full(struct cifs_dirent *de,
393                 const FILE_FULL_DIRECTORY_INFO *info)
394 {
395         de->name = &info->FileName[0];
396         de->namelen = le32_to_cpu(info->FileNameLength);
397         de->resume_key = info->FileIndex;
398 }
399
400 static void cifs_fill_dirent_search(struct cifs_dirent *de,
401                 const SEARCH_ID_FULL_DIR_INFO *info)
402 {
403         de->name = &info->FileName[0];
404         de->namelen = le32_to_cpu(info->FileNameLength);
405         de->resume_key = info->FileIndex;
406         de->ino = le64_to_cpu(info->UniqueId);
407 }
408
409 static void cifs_fill_dirent_both(struct cifs_dirent *de,
410                 const FILE_BOTH_DIRECTORY_INFO *info)
411 {
412         de->name = &info->FileName[0];
413         de->namelen = le32_to_cpu(info->FileNameLength);
414         de->resume_key = info->FileIndex;
415 }
416
417 static void cifs_fill_dirent_std(struct cifs_dirent *de,
418                 const FIND_FILE_STANDARD_INFO *info)
419 {
420         de->name = &info->FileName[0];
421         /* one byte length, no endianess conversion */
422         de->namelen = info->FileNameLength;
423         de->resume_key = info->ResumeKey;
424 }
425
426 static int cifs_fill_dirent(struct cifs_dirent *de, const void *info,
427                 u16 level, bool is_unicode)
428 {
429         memset(de, 0, sizeof(*de));
430
431         switch (level) {
432         case SMB_FIND_FILE_UNIX:
433                 cifs_fill_dirent_unix(de, info, is_unicode);
434                 break;
435         case SMB_FIND_FILE_DIRECTORY_INFO:
436                 cifs_fill_dirent_dir(de, info);
437                 break;
438         case SMB_FIND_FILE_FULL_DIRECTORY_INFO:
439                 cifs_fill_dirent_full(de, info);
440                 break;
441         case SMB_FIND_FILE_ID_FULL_DIR_INFO:
442                 cifs_fill_dirent_search(de, info);
443                 break;
444         case SMB_FIND_FILE_BOTH_DIRECTORY_INFO:
445                 cifs_fill_dirent_both(de, info);
446                 break;
447         case SMB_FIND_FILE_INFO_STANDARD:
448                 cifs_fill_dirent_std(de, info);
449                 break;
450         default:
451                 cFYI(1, "Unknown findfirst level %d", level);
452                 return -EINVAL;
453         }
454
455         return 0;
456 }
457
458 #define UNICODE_DOT cpu_to_le16(0x2e)
459
460 /* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
461 static int cifs_entry_is_dot(struct cifs_dirent *de, bool is_unicode)
462 {
463         int rc = 0;
464
465         if (!de->name)
466                 return 0;
467
468         if (is_unicode) {
469                 __le16 *ufilename = (__le16 *)de->name;
470                 if (de->namelen == 2) {
471                         /* check for . */
472                         if (ufilename[0] == UNICODE_DOT)
473                                 rc = 1;
474                 } else if (de->namelen == 4) {
475                         /* check for .. */
476                         if (ufilename[0] == UNICODE_DOT &&
477                             ufilename[1] == UNICODE_DOT)
478                                 rc = 2;
479                 }
480         } else /* ASCII */ {
481                 if (de->namelen == 1) {
482                         if (de->name[0] == '.')
483                                 rc = 1;
484                 } else if (de->namelen == 2) {
485                         if (de->name[0] == '.' && de->name[1] == '.')
486                                 rc = 2;
487                 }
488         }
489
490         return rc;
491 }
492
493 /* Check if directory that we are searching has changed so we can decide
494    whether we can use the cached search results from the previous search */
495 static int is_dir_changed(struct file *file)
496 {
497         struct inode *inode = file->f_path.dentry->d_inode;
498         struct cifsInodeInfo *cifsInfo = CIFS_I(inode);
499
500         if (cifsInfo->time == 0)
501                 return 1; /* directory was changed, perhaps due to unlink */
502         else
503                 return 0;
504
505 }
506
507 static int cifs_save_resume_key(const char *current_entry,
508         struct cifsFileInfo *file_info)
509 {
510         struct cifs_dirent de;
511         int rc;
512
513         rc = cifs_fill_dirent(&de, current_entry, file_info->srch_inf.info_level,
514                               file_info->srch_inf.unicode);
515         if (!rc) {
516                 file_info->srch_inf.presume_name = de.name;
517                 file_info->srch_inf.resume_name_len = de.namelen;
518                 file_info->srch_inf.resume_key = de.resume_key;
519         }
520         return rc;
521 }
522
523 /*
524  * Find the corresponding entry in the search. Note that the SMB server returns
525  * search entries for . and .. which complicates logic here if we choose to
526  * parse for them and we do not assume that they are located in the findfirst
527  * return buffer. We start counting in the buffer with entry 2 and increment for
528  * every entry (do not increment for . or .. entry).
529  */
530 static int
531 find_cifs_entry(const unsigned int xid, struct cifs_tcon *tcon,
532                 struct file *file, char **current_entry, int *num_to_ret)
533 {
534         __u16 search_flags;
535         int rc = 0;
536         int pos_in_buf = 0;
537         loff_t first_entry_in_buffer;
538         loff_t index_to_find = file->f_pos;
539         struct cifsFileInfo *cfile = file->private_data;
540         struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
541         struct TCP_Server_Info *server = tcon->ses->server;
542         /* check if index in the buffer */
543
544         if (!server->ops->query_dir_first || !server->ops->query_dir_next)
545                 return -ENOSYS;
546
547         if ((cfile == NULL) || (current_entry == NULL) || (num_to_ret == NULL))
548                 return -ENOENT;
549
550         *current_entry = NULL;
551         first_entry_in_buffer = cfile->srch_inf.index_of_last_entry -
552                                         cfile->srch_inf.entries_in_buffer;
553
554         /*
555          * If first entry in buf is zero then is first buffer
556          * in search response data which means it is likely . and ..
557          * will be in this buffer, although some servers do not return
558          * . and .. for the root of a drive and for those we need
559          * to start two entries earlier.
560          */
561
562         dump_cifs_file_struct(file, "In fce ");
563         if (((index_to_find < cfile->srch_inf.index_of_last_entry) &&
564              is_dir_changed(file)) || (index_to_find < first_entry_in_buffer)) {
565                 /* close and restart search */
566                 cFYI(1, "search backing up - close and restart search");
567                 spin_lock(&cifs_file_list_lock);
568                 if (!cfile->srch_inf.endOfSearch && !cfile->invalidHandle) {
569                         cfile->invalidHandle = true;
570                         spin_unlock(&cifs_file_list_lock);
571                         if (server->ops->close)
572                                 server->ops->close(xid, tcon, &cfile->fid);
573                 } else
574                         spin_unlock(&cifs_file_list_lock);
575                 if (cfile->srch_inf.ntwrk_buf_start) {
576                         cFYI(1, "freeing SMB ff cache buf on search rewind");
577                         if (cfile->srch_inf.smallBuf)
578                                 cifs_small_buf_release(cfile->srch_inf.
579                                                 ntwrk_buf_start);
580                         else
581                                 cifs_buf_release(cfile->srch_inf.
582                                                 ntwrk_buf_start);
583                         cfile->srch_inf.ntwrk_buf_start = NULL;
584                 }
585                 rc = initiate_cifs_search(xid, file);
586                 if (rc) {
587                         cFYI(1, "error %d reinitiating a search on rewind",
588                                  rc);
589                         return rc;
590                 }
591                 /* FindFirst/Next set last_entry to NULL on malformed reply */
592                 if (cfile->srch_inf.last_entry)
593                         cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
594         }
595
596         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
597         if (backup_cred(cifs_sb))
598                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
599
600         while ((index_to_find >= cfile->srch_inf.index_of_last_entry) &&
601                (rc == 0) && !cfile->srch_inf.endOfSearch) {
602                 cFYI(1, "calling findnext2");
603                 rc = server->ops->query_dir_next(xid, tcon, &cfile->fid,
604                                                  search_flags,
605                                                  &cfile->srch_inf);
606                 /* FindFirst/Next set last_entry to NULL on malformed reply */
607                 if (cfile->srch_inf.last_entry)
608                         cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
609                 if (rc)
610                         return -ENOENT;
611         }
612         if (index_to_find < cfile->srch_inf.index_of_last_entry) {
613                 /* we found the buffer that contains the entry */
614                 /* scan and find it */
615                 int i;
616                 char *cur_ent;
617                 char *end_of_smb = cfile->srch_inf.ntwrk_buf_start +
618                         server->ops->calc_smb_size(
619                                         cfile->srch_inf.ntwrk_buf_start);
620
621                 cur_ent = cfile->srch_inf.srch_entries_start;
622                 first_entry_in_buffer = cfile->srch_inf.index_of_last_entry
623                                         - cfile->srch_inf.entries_in_buffer;
624                 pos_in_buf = index_to_find - first_entry_in_buffer;
625                 cFYI(1, "found entry - pos_in_buf %d", pos_in_buf);
626
627                 for (i = 0; (i < (pos_in_buf)) && (cur_ent != NULL); i++) {
628                         /* go entry by entry figuring out which is first */
629                         cur_ent = nxt_dir_entry(cur_ent, end_of_smb,
630                                                 cfile->srch_inf.info_level);
631                 }
632                 if ((cur_ent == NULL) && (i < pos_in_buf)) {
633                         /* BB fixme - check if we should flag this error */
634                         cERROR(1, "reached end of buf searching for pos in buf"
635                                   " %d index to find %lld rc %d", pos_in_buf,
636                                   index_to_find, rc);
637                 }
638                 rc = 0;
639                 *current_entry = cur_ent;
640         } else {
641                 cFYI(1, "index not in buffer - could not findnext into it");
642                 return 0;
643         }
644
645         if (pos_in_buf >= cfile->srch_inf.entries_in_buffer) {
646                 cFYI(1, "can not return entries pos_in_buf beyond last");
647                 *num_to_ret = 0;
648         } else
649                 *num_to_ret = cfile->srch_inf.entries_in_buffer - pos_in_buf;
650
651         return rc;
652 }
653
654 static int cifs_filldir(char *find_entry, struct file *file, filldir_t filldir,
655                 void *dirent, char *scratch_buf, unsigned int max_len)
656 {
657         struct cifsFileInfo *file_info = file->private_data;
658         struct super_block *sb = file->f_path.dentry->d_sb;
659         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
660         struct cifs_dirent de = { NULL, };
661         struct cifs_fattr fattr;
662         struct qstr name;
663         int rc = 0;
664         ino_t ino;
665
666         rc = cifs_fill_dirent(&de, find_entry, file_info->srch_inf.info_level,
667                               file_info->srch_inf.unicode);
668         if (rc)
669                 return rc;
670
671         if (de.namelen > max_len) {
672                 cERROR(1, "bad search response length %zd past smb end",
673                           de.namelen);
674                 return -EINVAL;
675         }
676
677         /* skip . and .. since we added them first */
678         if (cifs_entry_is_dot(&de, file_info->srch_inf.unicode))
679                 return 0;
680
681         if (file_info->srch_inf.unicode) {
682                 struct nls_table *nlt = cifs_sb->local_nls;
683
684                 name.name = scratch_buf;
685                 name.len =
686                         cifs_from_utf16((char *)name.name, (__le16 *)de.name,
687                                         UNICODE_NAME_MAX,
688                                         min_t(size_t, de.namelen,
689                                               (size_t)max_len), nlt,
690                                         cifs_sb->mnt_cifs_flags &
691                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
692                 name.len -= nls_nullsize(nlt);
693         } else {
694                 name.name = de.name;
695                 name.len = de.namelen;
696         }
697
698         switch (file_info->srch_inf.info_level) {
699         case SMB_FIND_FILE_UNIX:
700                 cifs_unix_basic_to_fattr(&fattr,
701                                          &((FILE_UNIX_INFO *)find_entry)->basic,
702                                          cifs_sb);
703                 break;
704         case SMB_FIND_FILE_INFO_STANDARD:
705                 cifs_std_info_to_fattr(&fattr,
706                                        (FIND_FILE_STANDARD_INFO *)find_entry,
707                                        cifs_sb);
708                 break;
709         default:
710                 cifs_dir_info_to_fattr(&fattr,
711                                        (FILE_DIRECTORY_INFO *)find_entry,
712                                        cifs_sb);
713                 break;
714         }
715
716         if (de.ino && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
717                 fattr.cf_uniqueid = de.ino;
718         } else {
719                 fattr.cf_uniqueid = iunique(sb, ROOT_I);
720                 cifs_autodisable_serverino(cifs_sb);
721         }
722
723         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) &&
724             CIFSCouldBeMFSymlink(&fattr))
725                 /*
726                  * trying to get the type and mode can be slow,
727                  * so just call those regular files for now, and mark
728                  * for reval
729                  */
730                 fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
731
732         cifs_prime_dcache(file->f_dentry, &name, &fattr);
733
734         ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
735         rc = filldir(dirent, name.name, name.len, file->f_pos, ino,
736                      fattr.cf_dtype);
737         return rc;
738 }
739
740
741 int cifs_readdir(struct file *file, void *direntry, filldir_t filldir)
742 {
743         int rc = 0;
744         unsigned int xid;
745         int i;
746         struct cifs_tcon *tcon;
747         struct cifsFileInfo *cifsFile = NULL;
748         char *current_entry;
749         int num_to_fill = 0;
750         char *tmp_buf = NULL;
751         char *end_of_smb;
752         unsigned int max_len;
753
754         xid = get_xid();
755
756         /*
757          * Ensure FindFirst doesn't fail before doing filldir() for '.' and
758          * '..'. Otherwise we won't be able to notify VFS in case of failure.
759          */
760         if (file->private_data == NULL) {
761                 rc = initiate_cifs_search(xid, file);
762                 cFYI(1, "initiate cifs search rc %d", rc);
763                 if (rc)
764                         goto rddir2_exit;
765         }
766
767         switch ((int) file->f_pos) {
768         case 0:
769                 if (filldir(direntry, ".", 1, file->f_pos,
770                      file->f_path.dentry->d_inode->i_ino, DT_DIR) < 0) {
771                         cERROR(1, "Filldir for current dir failed");
772                         rc = -ENOMEM;
773                         break;
774                 }
775                 file->f_pos++;
776         case 1:
777                 if (filldir(direntry, "..", 2, file->f_pos,
778                      parent_ino(file->f_path.dentry), DT_DIR) < 0) {
779                         cERROR(1, "Filldir for parent dir failed");
780                         rc = -ENOMEM;
781                         break;
782                 }
783                 file->f_pos++;
784         default:
785                 /* 1) If search is active,
786                         is in current search buffer?
787                         if it before then restart search
788                         if after then keep searching till find it */
789
790                 if (file->private_data == NULL) {
791                         rc = -EINVAL;
792                         free_xid(xid);
793                         return rc;
794                 }
795                 cifsFile = file->private_data;
796                 if (cifsFile->srch_inf.endOfSearch) {
797                         if (cifsFile->srch_inf.emptyDir) {
798                                 cFYI(1, "End of search, empty dir");
799                                 rc = 0;
800                                 break;
801                         }
802                 } /* else {
803                         cifsFile->invalidHandle = true;
804                         tcon->ses->server->close(xid, tcon, &cifsFile->fid);
805                 } */
806
807                 tcon = tlink_tcon(cifsFile->tlink);
808                 rc = find_cifs_entry(xid, tcon, file, &current_entry,
809                                      &num_to_fill);
810                 if (rc) {
811                         cFYI(1, "fce error %d", rc);
812                         goto rddir2_exit;
813                 } else if (current_entry != NULL) {
814                         cFYI(1, "entry %lld found", file->f_pos);
815                 } else {
816                         cFYI(1, "could not find entry");
817                         goto rddir2_exit;
818                 }
819                 cFYI(1, "loop through %d times filling dir for net buf %p",
820                         num_to_fill, cifsFile->srch_inf.ntwrk_buf_start);
821                 max_len = tcon->ses->server->ops->calc_smb_size(
822                                 cifsFile->srch_inf.ntwrk_buf_start);
823                 end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len;
824
825                 tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL);
826                 if (tmp_buf == NULL) {
827                         rc = -ENOMEM;
828                         break;
829                 }
830
831                 for (i = 0; (i < num_to_fill) && (rc == 0); i++) {
832                         if (current_entry == NULL) {
833                                 /* evaluate whether this case is an error */
834                                 cERROR(1, "past SMB end,  num to fill %d i %d",
835                                           num_to_fill, i);
836                                 break;
837                         }
838                         /*
839                          * if buggy server returns . and .. late do we want to
840                          * check for that here?
841                          */
842                         rc = cifs_filldir(current_entry, file, filldir,
843                                           direntry, tmp_buf, max_len);
844                         if (rc == -EOVERFLOW) {
845                                 rc = 0;
846                                 break;
847                         }
848
849                         file->f_pos++;
850                         if (file->f_pos ==
851                                 cifsFile->srch_inf.index_of_last_entry) {
852                                 cFYI(1, "last entry in buf at pos %lld %s",
853                                         file->f_pos, tmp_buf);
854                                 cifs_save_resume_key(current_entry, cifsFile);
855                                 break;
856                         } else
857                                 current_entry =
858                                         nxt_dir_entry(current_entry, end_of_smb,
859                                                 cifsFile->srch_inf.info_level);
860                 }
861                 kfree(tmp_buf);
862                 break;
863         } /* end switch */
864
865 rddir2_exit:
866         free_xid(xid);
867         return rc;
868 }