GNU Linux-libre 4.9.308-gnu1
[releases.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                         cifs_dbg(FYI, "empty cifs private file data\n");
52                         return;
53                 }
54                 if (cf->invalidHandle)
55                         cifs_dbg(FYI, "invalid handle\n");
56                 if (cf->srch_inf.endOfSearch)
57                         cifs_dbg(FYI, "end of search\n");
58                 if (cf->srch_inf.emptyDir)
59                         cifs_dbg(FYI, "empty dir\n");
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 or filetype(mode) changed,
73  * then drop it and recreate it.
74  */
75 static void
76 cifs_prime_dcache(struct dentry *parent, struct qstr *name,
77                     struct cifs_fattr *fattr)
78 {
79         struct dentry *dentry, *alias;
80         struct inode *inode;
81         struct super_block *sb = parent->d_sb;
82         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
83         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
84
85         cifs_dbg(FYI, "%s: for %s\n", __func__, name->name);
86
87         dentry = d_hash_and_lookup(parent, name);
88         if (!dentry) {
89                 /*
90                  * If we know that the inode will need to be revalidated
91                  * immediately, then don't create a new dentry for it.
92                  * We'll end up doing an on the wire call either way and
93                  * this spares us an invalidation.
94                  */
95                 if (fattr->cf_flags & CIFS_FATTR_NEED_REVAL)
96                         return;
97 retry:
98                 dentry = d_alloc_parallel(parent, name, &wq);
99         }
100         if (IS_ERR(dentry))
101                 return;
102         if (!d_in_lookup(dentry)) {
103                 inode = d_inode(dentry);
104                 if (inode) {
105                         if (d_mountpoint(dentry)) {
106                                 dput(dentry);
107                                 return;
108                         }
109                         /*
110                          * If we're generating inode numbers, then we don't
111                          * want to clobber the existing one with the one that
112                          * the readdir code created.
113                          */
114                         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM))
115                                 fattr->cf_uniqueid = CIFS_I(inode)->uniqueid;
116
117                         /* update inode in place
118                          * if both i_ino and i_mode didn't change */
119                         if (CIFS_I(inode)->uniqueid == fattr->cf_uniqueid &&
120                             (inode->i_mode & S_IFMT) ==
121                             (fattr->cf_mode & S_IFMT)) {
122                                 cifs_fattr_to_inode(inode, fattr);
123                                 dput(dentry);
124                                 return;
125                         }
126                 }
127                 d_invalidate(dentry);
128                 dput(dentry);
129                 goto retry;
130         } else {
131                 inode = cifs_iget(sb, fattr);
132                 if (!inode)
133                         inode = ERR_PTR(-ENOMEM);
134                 alias = d_splice_alias(inode, dentry);
135                 d_lookup_done(dentry);
136                 if (alias && !IS_ERR(alias))
137                         dput(alias);
138         }
139         dput(dentry);
140 }
141
142 static void
143 cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb)
144 {
145         fattr->cf_uid = cifs_sb->mnt_uid;
146         fattr->cf_gid = cifs_sb->mnt_gid;
147
148         if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
149                 fattr->cf_mode = S_IFDIR | cifs_sb->mnt_dir_mode;
150                 fattr->cf_dtype = DT_DIR;
151         } else {
152                 fattr->cf_mode = S_IFREG | cifs_sb->mnt_file_mode;
153                 fattr->cf_dtype = DT_REG;
154         }
155
156         /*
157          * We need to revalidate it further to make a decision about whether it
158          * is a symbolic link, DFS referral or a reparse point with a direct
159          * access like junctions, deduplicated files, NFS symlinks.
160          */
161         if (fattr->cf_cifsattrs & ATTR_REPARSE)
162                 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
163
164         /* non-unix readdir doesn't provide nlink */
165         fattr->cf_flags |= CIFS_FATTR_UNKNOWN_NLINK;
166
167         if (fattr->cf_cifsattrs & ATTR_READONLY)
168                 fattr->cf_mode &= ~S_IWUGO;
169
170         /*
171          * We of course don't get ACL info in FIND_FIRST/NEXT results, so
172          * mark it for revalidation so that "ls -l" will look right. It might
173          * be super-slow, but if we don't do this then the ownership of files
174          * may look wrong since the inodes may not have timed out by the time
175          * "ls" does a stat() call on them.
176          */
177         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL)
178                 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
179
180         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL &&
181             fattr->cf_cifsattrs & ATTR_SYSTEM) {
182                 if (fattr->cf_eof == 0)  {
183                         fattr->cf_mode &= ~S_IFMT;
184                         fattr->cf_mode |= S_IFIFO;
185                         fattr->cf_dtype = DT_FIFO;
186                 } else {
187                         /*
188                          * trying to get the type and mode via SFU can be slow,
189                          * so just call those regular files for now, and mark
190                          * for reval
191                          */
192                         fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
193                 }
194         }
195 }
196
197 void
198 cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info,
199                        struct cifs_sb_info *cifs_sb)
200 {
201         memset(fattr, 0, sizeof(*fattr));
202         fattr->cf_cifsattrs = le32_to_cpu(info->ExtFileAttributes);
203         fattr->cf_eof = le64_to_cpu(info->EndOfFile);
204         fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
205         fattr->cf_createtime = le64_to_cpu(info->CreationTime);
206         fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
207         fattr->cf_ctime = cifs_NTtimeToUnix(info->ChangeTime);
208         fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);
209
210         cifs_fill_common_info(fattr, cifs_sb);
211 }
212
213 static void
214 cifs_std_info_to_fattr(struct cifs_fattr *fattr, FIND_FILE_STANDARD_INFO *info,
215                        struct cifs_sb_info *cifs_sb)
216 {
217         int offset = cifs_sb_master_tcon(cifs_sb)->ses->server->timeAdj;
218
219         memset(fattr, 0, sizeof(*fattr));
220         fattr->cf_atime = cnvrtDosUnixTm(info->LastAccessDate,
221                                             info->LastAccessTime, offset);
222         fattr->cf_ctime = cnvrtDosUnixTm(info->LastWriteDate,
223                                             info->LastWriteTime, offset);
224         fattr->cf_mtime = cnvrtDosUnixTm(info->LastWriteDate,
225                                             info->LastWriteTime, offset);
226
227         fattr->cf_cifsattrs = le16_to_cpu(info->Attributes);
228         fattr->cf_bytes = le32_to_cpu(info->AllocationSize);
229         fattr->cf_eof = le32_to_cpu(info->DataSize);
230
231         cifs_fill_common_info(fattr, cifs_sb);
232 }
233
234 /* BB eventually need to add the following helper function to
235       resolve NT_STATUS_STOPPED_ON_SYMLINK return code when
236       we try to do FindFirst on (NTFS) directory symlinks */
237 /*
238 int get_symlink_reparse_path(char *full_path, struct cifs_sb_info *cifs_sb,
239                              unsigned int xid)
240 {
241         __u16 fid;
242         int len;
243         int oplock = 0;
244         int rc;
245         struct cifs_tcon *ptcon = cifs_sb_tcon(cifs_sb);
246         char *tmpbuffer;
247
248         rc = CIFSSMBOpen(xid, ptcon, full_path, FILE_OPEN, GENERIC_READ,
249                         OPEN_REPARSE_POINT, &fid, &oplock, NULL,
250                         cifs_sb->local_nls,
251                         cifs_remap(cifs_sb);
252         if (!rc) {
253                 tmpbuffer = kmalloc(maxpath);
254                 rc = CIFSSMBQueryReparseLinkInfo(xid, ptcon, full_path,
255                                 tmpbuffer,
256                                 maxpath -1,
257                                 fid,
258                                 cifs_sb->local_nls);
259                 if (CIFSSMBClose(xid, ptcon, fid)) {
260                         cifs_dbg(FYI, "Error closing temporary reparsepoint open\n");
261                 }
262         }
263 }
264  */
265
266 static int
267 initiate_cifs_search(const unsigned int xid, struct file *file)
268 {
269         __u16 search_flags;
270         int rc = 0;
271         char *full_path = NULL;
272         struct cifsFileInfo *cifsFile;
273         struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
274         struct tcon_link *tlink = NULL;
275         struct cifs_tcon *tcon;
276         struct TCP_Server_Info *server;
277
278         if (file->private_data == NULL) {
279                 tlink = cifs_sb_tlink(cifs_sb);
280                 if (IS_ERR(tlink))
281                         return PTR_ERR(tlink);
282
283                 cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
284                 if (cifsFile == NULL) {
285                         rc = -ENOMEM;
286                         goto error_exit;
287                 }
288                 spin_lock_init(&cifsFile->file_info_lock);
289                 file->private_data = cifsFile;
290                 cifsFile->tlink = cifs_get_tlink(tlink);
291                 tcon = tlink_tcon(tlink);
292         } else {
293                 cifsFile = file->private_data;
294                 tcon = tlink_tcon(cifsFile->tlink);
295         }
296
297         server = tcon->ses->server;
298
299         if (!server->ops->query_dir_first) {
300                 rc = -ENOSYS;
301                 goto error_exit;
302         }
303
304         cifsFile->invalidHandle = true;
305         cifsFile->srch_inf.endOfSearch = false;
306
307         full_path = build_path_from_dentry(file_dentry(file));
308         if (full_path == NULL) {
309                 rc = -ENOMEM;
310                 goto error_exit;
311         }
312
313         cifs_dbg(FYI, "Full path: %s start at: %lld\n", full_path, file->f_pos);
314
315 ffirst_retry:
316         /* test for Unix extensions */
317         /* but now check for them on the share/mount not on the SMB session */
318         /* if (cap_unix(tcon->ses) { */
319         if (tcon->unix_ext)
320                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
321         else if ((tcon->ses->capabilities &
322                   tcon->ses->server->vals->cap_nt_find) == 0) {
323                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD;
324         } else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
325                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
326         } else /* not srvinos - BB fixme add check for backlevel? */ {
327                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_DIRECTORY_INFO;
328         }
329
330         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
331         if (backup_cred(cifs_sb))
332                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
333
334         rc = server->ops->query_dir_first(xid, tcon, full_path, cifs_sb,
335                                           &cifsFile->fid, search_flags,
336                                           &cifsFile->srch_inf);
337
338         if (rc == 0)
339                 cifsFile->invalidHandle = false;
340         /* BB add following call to handle readdir on new NTFS symlink errors
341         else if STATUS_STOPPED_ON_SYMLINK
342                 call get_symlink_reparse_path and retry with new path */
343         else if ((rc == -EOPNOTSUPP) &&
344                 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
345                 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
346                 goto ffirst_retry;
347         }
348 error_exit:
349         kfree(full_path);
350         cifs_put_tlink(tlink);
351         return rc;
352 }
353
354 /* return length of unicode string in bytes */
355 static int cifs_unicode_bytelen(const char *str)
356 {
357         int len;
358         const __le16 *ustr = (const __le16 *)str;
359
360         for (len = 0; len <= PATH_MAX; len++) {
361                 if (ustr[len] == 0)
362                         return len << 1;
363         }
364         cifs_dbg(FYI, "Unicode string longer than PATH_MAX found\n");
365         return len << 1;
366 }
367
368 static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
369 {
370         char *new_entry;
371         FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry;
372
373         if (level == SMB_FIND_FILE_INFO_STANDARD) {
374                 FIND_FILE_STANDARD_INFO *pfData;
375                 pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo;
376
377                 new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) +
378                                 pfData->FileNameLength;
379         } else {
380                 u32 next_offset = le32_to_cpu(pDirInfo->NextEntryOffset);
381
382                 if (old_entry + next_offset < old_entry) {
383                         cifs_dbg(VFS, "invalid offset %u\n", next_offset);
384                         return NULL;
385                 }
386                 new_entry = old_entry + next_offset;
387         }
388         cifs_dbg(FYI, "new entry %p old entry %p\n", new_entry, old_entry);
389         /* validate that new_entry is not past end of SMB */
390         if (new_entry >= end_of_smb) {
391                 cifs_dbg(VFS, "search entry %p began after end of SMB %p old entry %p\n",
392                          new_entry, end_of_smb, old_entry);
393                 return NULL;
394         } else if (((level == SMB_FIND_FILE_INFO_STANDARD) &&
395                     (new_entry + sizeof(FIND_FILE_STANDARD_INFO) > end_of_smb))
396                   || ((level != SMB_FIND_FILE_INFO_STANDARD) &&
397                    (new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb)))  {
398                 cifs_dbg(VFS, "search entry %p extends after end of SMB %p\n",
399                          new_entry, end_of_smb);
400                 return NULL;
401         } else
402                 return new_entry;
403
404 }
405
406 struct cifs_dirent {
407         const char      *name;
408         size_t          namelen;
409         u32             resume_key;
410         u64             ino;
411 };
412
413 static void cifs_fill_dirent_unix(struct cifs_dirent *de,
414                 const FILE_UNIX_INFO *info, bool is_unicode)
415 {
416         de->name = &info->FileName[0];
417         if (is_unicode)
418                 de->namelen = cifs_unicode_bytelen(de->name);
419         else
420                 de->namelen = strnlen(de->name, PATH_MAX);
421         de->resume_key = info->ResumeKey;
422         de->ino = le64_to_cpu(info->basic.UniqueId);
423 }
424
425 static void cifs_fill_dirent_dir(struct cifs_dirent *de,
426                 const FILE_DIRECTORY_INFO *info)
427 {
428         de->name = &info->FileName[0];
429         de->namelen = le32_to_cpu(info->FileNameLength);
430         de->resume_key = info->FileIndex;
431 }
432
433 static void cifs_fill_dirent_full(struct cifs_dirent *de,
434                 const FILE_FULL_DIRECTORY_INFO *info)
435 {
436         de->name = &info->FileName[0];
437         de->namelen = le32_to_cpu(info->FileNameLength);
438         de->resume_key = info->FileIndex;
439 }
440
441 static void cifs_fill_dirent_search(struct cifs_dirent *de,
442                 const SEARCH_ID_FULL_DIR_INFO *info)
443 {
444         de->name = &info->FileName[0];
445         de->namelen = le32_to_cpu(info->FileNameLength);
446         de->resume_key = info->FileIndex;
447         de->ino = le64_to_cpu(info->UniqueId);
448 }
449
450 static void cifs_fill_dirent_both(struct cifs_dirent *de,
451                 const FILE_BOTH_DIRECTORY_INFO *info)
452 {
453         de->name = &info->FileName[0];
454         de->namelen = le32_to_cpu(info->FileNameLength);
455         de->resume_key = info->FileIndex;
456 }
457
458 static void cifs_fill_dirent_std(struct cifs_dirent *de,
459                 const FIND_FILE_STANDARD_INFO *info)
460 {
461         de->name = &info->FileName[0];
462         /* one byte length, no endianess conversion */
463         de->namelen = info->FileNameLength;
464         de->resume_key = info->ResumeKey;
465 }
466
467 static int cifs_fill_dirent(struct cifs_dirent *de, const void *info,
468                 u16 level, bool is_unicode)
469 {
470         memset(de, 0, sizeof(*de));
471
472         switch (level) {
473         case SMB_FIND_FILE_UNIX:
474                 cifs_fill_dirent_unix(de, info, is_unicode);
475                 break;
476         case SMB_FIND_FILE_DIRECTORY_INFO:
477                 cifs_fill_dirent_dir(de, info);
478                 break;
479         case SMB_FIND_FILE_FULL_DIRECTORY_INFO:
480                 cifs_fill_dirent_full(de, info);
481                 break;
482         case SMB_FIND_FILE_ID_FULL_DIR_INFO:
483                 cifs_fill_dirent_search(de, info);
484                 break;
485         case SMB_FIND_FILE_BOTH_DIRECTORY_INFO:
486                 cifs_fill_dirent_both(de, info);
487                 break;
488         case SMB_FIND_FILE_INFO_STANDARD:
489                 cifs_fill_dirent_std(de, info);
490                 break;
491         default:
492                 cifs_dbg(FYI, "Unknown findfirst level %d\n", level);
493                 return -EINVAL;
494         }
495
496         return 0;
497 }
498
499 #define UNICODE_DOT cpu_to_le16(0x2e)
500
501 /* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
502 static int cifs_entry_is_dot(struct cifs_dirent *de, bool is_unicode)
503 {
504         int rc = 0;
505
506         if (!de->name)
507                 return 0;
508
509         if (is_unicode) {
510                 __le16 *ufilename = (__le16 *)de->name;
511                 if (de->namelen == 2) {
512                         /* check for . */
513                         if (ufilename[0] == UNICODE_DOT)
514                                 rc = 1;
515                 } else if (de->namelen == 4) {
516                         /* check for .. */
517                         if (ufilename[0] == UNICODE_DOT &&
518                             ufilename[1] == UNICODE_DOT)
519                                 rc = 2;
520                 }
521         } else /* ASCII */ {
522                 if (de->namelen == 1) {
523                         if (de->name[0] == '.')
524                                 rc = 1;
525                 } else if (de->namelen == 2) {
526                         if (de->name[0] == '.' && de->name[1] == '.')
527                                 rc = 2;
528                 }
529         }
530
531         return rc;
532 }
533
534 /* Check if directory that we are searching has changed so we can decide
535    whether we can use the cached search results from the previous search */
536 static int is_dir_changed(struct file *file)
537 {
538         struct inode *inode = file_inode(file);
539         struct cifsInodeInfo *cifsInfo = CIFS_I(inode);
540
541         if (cifsInfo->time == 0)
542                 return 1; /* directory was changed, perhaps due to unlink */
543         else
544                 return 0;
545
546 }
547
548 static int cifs_save_resume_key(const char *current_entry,
549         struct cifsFileInfo *file_info)
550 {
551         struct cifs_dirent de;
552         int rc;
553
554         rc = cifs_fill_dirent(&de, current_entry, file_info->srch_inf.info_level,
555                               file_info->srch_inf.unicode);
556         if (!rc) {
557                 file_info->srch_inf.presume_name = de.name;
558                 file_info->srch_inf.resume_name_len = de.namelen;
559                 file_info->srch_inf.resume_key = de.resume_key;
560         }
561         return rc;
562 }
563
564 /*
565  * Find the corresponding entry in the search. Note that the SMB server returns
566  * search entries for . and .. which complicates logic here if we choose to
567  * parse for them and we do not assume that they are located in the findfirst
568  * return buffer. We start counting in the buffer with entry 2 and increment for
569  * every entry (do not increment for . or .. entry).
570  */
571 static int
572 find_cifs_entry(const unsigned int xid, struct cifs_tcon *tcon, loff_t pos,
573                 struct file *file, char **current_entry, int *num_to_ret)
574 {
575         __u16 search_flags;
576         int rc = 0;
577         int pos_in_buf = 0;
578         loff_t first_entry_in_buffer;
579         loff_t index_to_find = pos;
580         struct cifsFileInfo *cfile = file->private_data;
581         struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
582         struct TCP_Server_Info *server = tcon->ses->server;
583         /* check if index in the buffer */
584
585         if (!server->ops->query_dir_first || !server->ops->query_dir_next)
586                 return -ENOSYS;
587
588         if ((cfile == NULL) || (current_entry == NULL) || (num_to_ret == NULL))
589                 return -ENOENT;
590
591         *current_entry = NULL;
592         first_entry_in_buffer = cfile->srch_inf.index_of_last_entry -
593                                         cfile->srch_inf.entries_in_buffer;
594
595         /*
596          * If first entry in buf is zero then is first buffer
597          * in search response data which means it is likely . and ..
598          * will be in this buffer, although some servers do not return
599          * . and .. for the root of a drive and for those we need
600          * to start two entries earlier.
601          */
602
603         dump_cifs_file_struct(file, "In fce ");
604         if (((index_to_find < cfile->srch_inf.index_of_last_entry) &&
605              is_dir_changed(file)) || (index_to_find < first_entry_in_buffer)) {
606                 /* close and restart search */
607                 cifs_dbg(FYI, "search backing up - close and restart search\n");
608                 spin_lock(&cfile->file_info_lock);
609                 if (server->ops->dir_needs_close(cfile)) {
610                         cfile->invalidHandle = true;
611                         spin_unlock(&cfile->file_info_lock);
612                         if (server->ops->close_dir)
613                                 server->ops->close_dir(xid, tcon, &cfile->fid);
614                 } else
615                         spin_unlock(&cfile->file_info_lock);
616                 if (cfile->srch_inf.ntwrk_buf_start) {
617                         cifs_dbg(FYI, "freeing SMB ff cache buf on search rewind\n");
618                         if (cfile->srch_inf.smallBuf)
619                                 cifs_small_buf_release(cfile->srch_inf.
620                                                 ntwrk_buf_start);
621                         else
622                                 cifs_buf_release(cfile->srch_inf.
623                                                 ntwrk_buf_start);
624                         cfile->srch_inf.ntwrk_buf_start = NULL;
625                 }
626                 rc = initiate_cifs_search(xid, file);
627                 if (rc) {
628                         cifs_dbg(FYI, "error %d reinitiating a search on rewind\n",
629                                  rc);
630                         return rc;
631                 }
632                 /* FindFirst/Next set last_entry to NULL on malformed reply */
633                 if (cfile->srch_inf.last_entry)
634                         cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
635         }
636
637         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
638         if (backup_cred(cifs_sb))
639                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
640
641         while ((index_to_find >= cfile->srch_inf.index_of_last_entry) &&
642                (rc == 0) && !cfile->srch_inf.endOfSearch) {
643                 cifs_dbg(FYI, "calling findnext2\n");
644                 rc = server->ops->query_dir_next(xid, tcon, &cfile->fid,
645                                                  search_flags,
646                                                  &cfile->srch_inf);
647                 /* FindFirst/Next set last_entry to NULL on malformed reply */
648                 if (cfile->srch_inf.last_entry)
649                         cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
650                 if (rc)
651                         return -ENOENT;
652         }
653         if (index_to_find < cfile->srch_inf.index_of_last_entry) {
654                 /* we found the buffer that contains the entry */
655                 /* scan and find it */
656                 int i;
657                 char *cur_ent;
658                 char *end_of_smb;
659
660                 if (cfile->srch_inf.ntwrk_buf_start == NULL) {
661                         cifs_dbg(VFS, "ntwrk_buf_start is NULL during readdir\n");
662                         return -EIO;
663                 }
664
665                 end_of_smb = cfile->srch_inf.ntwrk_buf_start +
666                         server->ops->calc_smb_size(
667                                         cfile->srch_inf.ntwrk_buf_start);
668
669                 cur_ent = cfile->srch_inf.srch_entries_start;
670                 first_entry_in_buffer = cfile->srch_inf.index_of_last_entry
671                                         - cfile->srch_inf.entries_in_buffer;
672                 pos_in_buf = index_to_find - first_entry_in_buffer;
673                 cifs_dbg(FYI, "found entry - pos_in_buf %d\n", pos_in_buf);
674
675                 for (i = 0; (i < (pos_in_buf)) && (cur_ent != NULL); i++) {
676                         /* go entry by entry figuring out which is first */
677                         cur_ent = nxt_dir_entry(cur_ent, end_of_smb,
678                                                 cfile->srch_inf.info_level);
679                 }
680                 if ((cur_ent == NULL) && (i < pos_in_buf)) {
681                         /* BB fixme - check if we should flag this error */
682                         cifs_dbg(VFS, "reached end of buf searching for pos in buf %d index to find %lld rc %d\n",
683                                  pos_in_buf, index_to_find, rc);
684                 }
685                 rc = 0;
686                 *current_entry = cur_ent;
687         } else {
688                 cifs_dbg(FYI, "index not in buffer - could not findnext into it\n");
689                 return 0;
690         }
691
692         if (pos_in_buf >= cfile->srch_inf.entries_in_buffer) {
693                 cifs_dbg(FYI, "can not return entries pos_in_buf beyond last\n");
694                 *num_to_ret = 0;
695         } else
696                 *num_to_ret = cfile->srch_inf.entries_in_buffer - pos_in_buf;
697
698         return rc;
699 }
700
701 static int cifs_filldir(char *find_entry, struct file *file,
702                 struct dir_context *ctx,
703                 char *scratch_buf, unsigned int max_len)
704 {
705         struct cifsFileInfo *file_info = file->private_data;
706         struct super_block *sb = file_inode(file)->i_sb;
707         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
708         struct cifs_dirent de = { NULL, };
709         struct cifs_fattr fattr;
710         struct qstr name;
711         int rc = 0;
712         ino_t ino;
713
714         rc = cifs_fill_dirent(&de, find_entry, file_info->srch_inf.info_level,
715                               file_info->srch_inf.unicode);
716         if (rc)
717                 return rc;
718
719         if (de.namelen > max_len) {
720                 cifs_dbg(VFS, "bad search response length %zd past smb end\n",
721                          de.namelen);
722                 return -EINVAL;
723         }
724
725         /* skip . and .. since we added them first */
726         if (cifs_entry_is_dot(&de, file_info->srch_inf.unicode))
727                 return 0;
728
729         if (file_info->srch_inf.unicode) {
730                 struct nls_table *nlt = cifs_sb->local_nls;
731                 int map_type;
732
733                 map_type = cifs_remap(cifs_sb);
734                 name.name = scratch_buf;
735                 name.len =
736                         cifs_from_utf16((char *)name.name, (__le16 *)de.name,
737                                         UNICODE_NAME_MAX,
738                                         min_t(size_t, de.namelen,
739                                               (size_t)max_len), nlt, map_type);
740                 name.len -= nls_nullsize(nlt);
741         } else {
742                 name.name = de.name;
743                 name.len = de.namelen;
744         }
745
746         switch (file_info->srch_inf.info_level) {
747         case SMB_FIND_FILE_UNIX:
748                 cifs_unix_basic_to_fattr(&fattr,
749                                          &((FILE_UNIX_INFO *)find_entry)->basic,
750                                          cifs_sb);
751                 break;
752         case SMB_FIND_FILE_INFO_STANDARD:
753                 cifs_std_info_to_fattr(&fattr,
754                                        (FIND_FILE_STANDARD_INFO *)find_entry,
755                                        cifs_sb);
756                 break;
757         default:
758                 cifs_dir_info_to_fattr(&fattr,
759                                        (FILE_DIRECTORY_INFO *)find_entry,
760                                        cifs_sb);
761                 break;
762         }
763
764         if (de.ino && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
765                 fattr.cf_uniqueid = de.ino;
766         } else {
767                 fattr.cf_uniqueid = iunique(sb, ROOT_I);
768                 cifs_autodisable_serverino(cifs_sb);
769         }
770
771         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) &&
772             couldbe_mf_symlink(&fattr))
773                 /*
774                  * trying to get the type and mode can be slow,
775                  * so just call those regular files for now, and mark
776                  * for reval
777                  */
778                 fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
779
780         cifs_prime_dcache(file_dentry(file), &name, &fattr);
781
782         ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
783         return !dir_emit(ctx, name.name, name.len, ino, fattr.cf_dtype);
784 }
785
786
787 int cifs_readdir(struct file *file, struct dir_context *ctx)
788 {
789         int rc = 0;
790         unsigned int xid;
791         int i;
792         struct cifs_tcon *tcon;
793         struct cifsFileInfo *cifsFile = NULL;
794         char *current_entry;
795         int num_to_fill = 0;
796         char *tmp_buf = NULL;
797         char *end_of_smb;
798         unsigned int max_len;
799
800         xid = get_xid();
801
802         /*
803          * Ensure FindFirst doesn't fail before doing filldir() for '.' and
804          * '..'. Otherwise we won't be able to notify VFS in case of failure.
805          */
806         if (file->private_data == NULL) {
807                 rc = initiate_cifs_search(xid, file);
808                 cifs_dbg(FYI, "initiate cifs search rc %d\n", rc);
809                 if (rc)
810                         goto rddir2_exit;
811         }
812
813         if (!dir_emit_dots(file, ctx))
814                 goto rddir2_exit;
815
816         /* 1) If search is active,
817                 is in current search buffer?
818                 if it before then restart search
819                 if after then keep searching till find it */
820
821         cifsFile = file->private_data;
822         if (cifsFile->srch_inf.endOfSearch) {
823                 if (cifsFile->srch_inf.emptyDir) {
824                         cifs_dbg(FYI, "End of search, empty dir\n");
825                         rc = 0;
826                         goto rddir2_exit;
827                 }
828         } /* else {
829                 cifsFile->invalidHandle = true;
830                 tcon->ses->server->close(xid, tcon, &cifsFile->fid);
831         } */
832
833         tcon = tlink_tcon(cifsFile->tlink);
834         rc = find_cifs_entry(xid, tcon, ctx->pos, file, &current_entry,
835                              &num_to_fill);
836         if (rc) {
837                 cifs_dbg(FYI, "fce error %d\n", rc);
838                 goto rddir2_exit;
839         } else if (current_entry != NULL) {
840                 cifs_dbg(FYI, "entry %lld found\n", ctx->pos);
841         } else {
842                 cifs_dbg(FYI, "could not find entry\n");
843                 goto rddir2_exit;
844         }
845         cifs_dbg(FYI, "loop through %d times filling dir for net buf %p\n",
846                  num_to_fill, cifsFile->srch_inf.ntwrk_buf_start);
847         max_len = tcon->ses->server->ops->calc_smb_size(
848                         cifsFile->srch_inf.ntwrk_buf_start);
849         end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len;
850
851         tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL);
852         if (tmp_buf == NULL) {
853                 rc = -ENOMEM;
854                 goto rddir2_exit;
855         }
856
857         for (i = 0; i < num_to_fill; i++) {
858                 if (current_entry == NULL) {
859                         /* evaluate whether this case is an error */
860                         cifs_dbg(VFS, "past SMB end,  num to fill %d i %d\n",
861                                  num_to_fill, i);
862                         break;
863                 }
864                 /*
865                  * if buggy server returns . and .. late do we want to
866                  * check for that here?
867                  */
868                 *tmp_buf = 0;
869                 rc = cifs_filldir(current_entry, file, ctx,
870                                   tmp_buf, max_len);
871                 if (rc) {
872                         if (rc > 0)
873                                 rc = 0;
874                         break;
875                 }
876
877                 ctx->pos++;
878                 if (ctx->pos ==
879                         cifsFile->srch_inf.index_of_last_entry) {
880                         cifs_dbg(FYI, "last entry in buf at pos %lld %s\n",
881                                  ctx->pos, tmp_buf);
882                         cifs_save_resume_key(current_entry, cifsFile);
883                         break;
884                 } else
885                         current_entry =
886                                 nxt_dir_entry(current_entry, end_of_smb,
887                                         cifsFile->srch_inf.info_level);
888         }
889         kfree(tmp_buf);
890
891 rddir2_exit:
892         free_xid(xid);
893         return rc;
894 }