Merge tag 'xtensa-next-20130710' of git://github.com/czankel/xtensa-linux
[platform/adaptation/renesas_rcar/renesas_kernel.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 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         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
82
83         cifs_dbg(FYI, "%s: for %s\n", __func__, name->name);
84
85         dentry = d_hash_and_lookup(parent, name);
86         if (unlikely(IS_ERR(dentry)))
87                 return;
88
89         if (dentry) {
90                 int err;
91
92                 inode = dentry->d_inode;
93                 if (inode) {
94                         /*
95                          * If we're generating inode numbers, then we don't
96                          * want to clobber the existing one with the one that
97                          * the readdir code created.
98                          */
99                         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM))
100                                 fattr->cf_uniqueid = CIFS_I(inode)->uniqueid;
101
102                         /* update inode in place if i_ino didn't change */
103                         if (CIFS_I(inode)->uniqueid == fattr->cf_uniqueid) {
104                                 cifs_fattr_to_inode(inode, fattr);
105                                 goto out;
106                         }
107                 }
108                 err = d_invalidate(dentry);
109                 dput(dentry);
110                 if (err)
111                         return;
112         }
113
114         dentry = d_alloc(parent, name);
115         if (!dentry)
116                 return;
117
118         inode = cifs_iget(sb, fattr);
119         if (!inode)
120                 goto out;
121
122         alias = d_materialise_unique(dentry, inode);
123         if (alias && !IS_ERR(alias))
124                 dput(alias);
125 out:
126         dput(dentry);
127 }
128
129 /*
130  * Is it possible that this directory might turn out to be a DFS referral
131  * once we go to try and use it?
132  */
133 static bool
134 cifs_dfs_is_possible(struct cifs_sb_info *cifs_sb)
135 {
136 #ifdef CONFIG_CIFS_DFS_UPCALL
137         struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
138
139         if (tcon->Flags & SMB_SHARE_IS_IN_DFS)
140                 return true;
141 #endif
142         return false;
143 }
144
145 static void
146 cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb)
147 {
148         fattr->cf_uid = cifs_sb->mnt_uid;
149         fattr->cf_gid = cifs_sb->mnt_gid;
150
151         if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
152                 fattr->cf_mode = S_IFDIR | cifs_sb->mnt_dir_mode;
153                 fattr->cf_dtype = DT_DIR;
154                 /*
155                  * Windows CIFS servers generally make DFS referrals look
156                  * like directories in FIND_* responses with the reparse
157                  * attribute flag also set (since DFS junctions are
158                  * reparse points). We must revalidate at least these
159                  * directory inodes before trying to use them (if
160                  * they are DFS we will get PATH_NOT_COVERED back
161                  * when queried directly and can then try to connect
162                  * to the DFS target)
163                  */
164                 if (cifs_dfs_is_possible(cifs_sb) &&
165                     (fattr->cf_cifsattrs & ATTR_REPARSE))
166                         fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
167         } else {
168                 fattr->cf_mode = S_IFREG | cifs_sb->mnt_file_mode;
169                 fattr->cf_dtype = DT_REG;
170         }
171
172         if (fattr->cf_cifsattrs & ATTR_READONLY)
173                 fattr->cf_mode &= ~S_IWUGO;
174
175         /*
176          * We of course don't get ACL info in FIND_FIRST/NEXT results, so
177          * mark it for revalidation so that "ls -l" will look right. It might
178          * be super-slow, but if we don't do this then the ownership of files
179          * may look wrong since the inodes may not have timed out by the time
180          * "ls" does a stat() call on them.
181          */
182         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL)
183                 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
184
185         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL &&
186             fattr->cf_cifsattrs & ATTR_SYSTEM) {
187                 if (fattr->cf_eof == 0)  {
188                         fattr->cf_mode &= ~S_IFMT;
189                         fattr->cf_mode |= S_IFIFO;
190                         fattr->cf_dtype = DT_FIFO;
191                 } else {
192                         /*
193                          * trying to get the type and mode via SFU can be slow,
194                          * so just call those regular files for now, and mark
195                          * for reval
196                          */
197                         fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
198                 }
199         }
200 }
201
202 void
203 cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info,
204                        struct cifs_sb_info *cifs_sb)
205 {
206         memset(fattr, 0, sizeof(*fattr));
207         fattr->cf_cifsattrs = le32_to_cpu(info->ExtFileAttributes);
208         fattr->cf_eof = le64_to_cpu(info->EndOfFile);
209         fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
210         fattr->cf_createtime = le64_to_cpu(info->CreationTime);
211         fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
212         fattr->cf_ctime = cifs_NTtimeToUnix(info->ChangeTime);
213         fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);
214
215         cifs_fill_common_info(fattr, cifs_sb);
216 }
217
218 static void
219 cifs_std_info_to_fattr(struct cifs_fattr *fattr, FIND_FILE_STANDARD_INFO *info,
220                        struct cifs_sb_info *cifs_sb)
221 {
222         int offset = cifs_sb_master_tcon(cifs_sb)->ses->server->timeAdj;
223
224         memset(fattr, 0, sizeof(*fattr));
225         fattr->cf_atime = cnvrtDosUnixTm(info->LastAccessDate,
226                                             info->LastAccessTime, offset);
227         fattr->cf_ctime = cnvrtDosUnixTm(info->LastWriteDate,
228                                             info->LastWriteTime, offset);
229         fattr->cf_mtime = cnvrtDosUnixTm(info->LastWriteDate,
230                                             info->LastWriteTime, offset);
231
232         fattr->cf_cifsattrs = le16_to_cpu(info->Attributes);
233         fattr->cf_bytes = le32_to_cpu(info->AllocationSize);
234         fattr->cf_eof = le32_to_cpu(info->DataSize);
235
236         cifs_fill_common_info(fattr, cifs_sb);
237 }
238
239 /* BB eventually need to add the following helper function to
240       resolve NT_STATUS_STOPPED_ON_SYMLINK return code when
241       we try to do FindFirst on (NTFS) directory symlinks */
242 /*
243 int get_symlink_reparse_path(char *full_path, struct cifs_sb_info *cifs_sb,
244                              unsigned int xid)
245 {
246         __u16 fid;
247         int len;
248         int oplock = 0;
249         int rc;
250         struct cifs_tcon *ptcon = cifs_sb_tcon(cifs_sb);
251         char *tmpbuffer;
252
253         rc = CIFSSMBOpen(xid, ptcon, full_path, FILE_OPEN, GENERIC_READ,
254                         OPEN_REPARSE_POINT, &fid, &oplock, NULL,
255                         cifs_sb->local_nls,
256                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
257         if (!rc) {
258                 tmpbuffer = kmalloc(maxpath);
259                 rc = CIFSSMBQueryReparseLinkInfo(xid, ptcon, full_path,
260                                 tmpbuffer,
261                                 maxpath -1,
262                                 fid,
263                                 cifs_sb->local_nls);
264                 if (CIFSSMBClose(xid, ptcon, fid)) {
265                         cifs_dbg(FYI, "Error closing temporary reparsepoint open\n");
266                 }
267         }
268 }
269  */
270
271 static int
272 initiate_cifs_search(const unsigned int xid, struct file *file)
273 {
274         __u16 search_flags;
275         int rc = 0;
276         char *full_path = NULL;
277         struct cifsFileInfo *cifsFile;
278         struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
279         struct tcon_link *tlink = NULL;
280         struct cifs_tcon *tcon;
281         struct TCP_Server_Info *server;
282
283         if (file->private_data == NULL) {
284                 tlink = cifs_sb_tlink(cifs_sb);
285                 if (IS_ERR(tlink))
286                         return PTR_ERR(tlink);
287
288                 cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
289                 if (cifsFile == NULL) {
290                         rc = -ENOMEM;
291                         goto error_exit;
292                 }
293                 file->private_data = cifsFile;
294                 cifsFile->tlink = cifs_get_tlink(tlink);
295                 tcon = tlink_tcon(tlink);
296         } else {
297                 cifsFile = file->private_data;
298                 tcon = tlink_tcon(cifsFile->tlink);
299         }
300
301         server = tcon->ses->server;
302
303         if (!server->ops->query_dir_first) {
304                 rc = -ENOSYS;
305                 goto error_exit;
306         }
307
308         cifsFile->invalidHandle = true;
309         cifsFile->srch_inf.endOfSearch = false;
310
311         full_path = build_path_from_dentry(file->f_path.dentry);
312         if (full_path == NULL) {
313                 rc = -ENOMEM;
314                 goto error_exit;
315         }
316
317         cifs_dbg(FYI, "Full path: %s start at: %lld\n", full_path, file->f_pos);
318
319 ffirst_retry:
320         /* test for Unix extensions */
321         /* but now check for them on the share/mount not on the SMB session */
322         /* if (cap_unix(tcon->ses) { */
323         if (tcon->unix_ext)
324                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
325         else if ((tcon->ses->capabilities &
326                   tcon->ses->server->vals->cap_nt_find) == 0) {
327                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD;
328         } else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
329                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
330         } else /* not srvinos - BB fixme add check for backlevel? */ {
331                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_DIRECTORY_INFO;
332         }
333
334         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
335         if (backup_cred(cifs_sb))
336                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
337
338         rc = server->ops->query_dir_first(xid, tcon, full_path, cifs_sb,
339                                           &cifsFile->fid, search_flags,
340                                           &cifsFile->srch_inf);
341
342         if (rc == 0)
343                 cifsFile->invalidHandle = false;
344         /* BB add following call to handle readdir on new NTFS symlink errors
345         else if STATUS_STOPPED_ON_SYMLINK
346                 call get_symlink_reparse_path and retry with new path */
347         else if ((rc == -EOPNOTSUPP) &&
348                 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
349                 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
350                 goto ffirst_retry;
351         }
352 error_exit:
353         kfree(full_path);
354         cifs_put_tlink(tlink);
355         return rc;
356 }
357
358 /* return length of unicode string in bytes */
359 static int cifs_unicode_bytelen(const char *str)
360 {
361         int len;
362         const __le16 *ustr = (const __le16 *)str;
363
364         for (len = 0; len <= PATH_MAX; len++) {
365                 if (ustr[len] == 0)
366                         return len << 1;
367         }
368         cifs_dbg(FYI, "Unicode string longer than PATH_MAX found\n");
369         return len << 1;
370 }
371
372 static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
373 {
374         char *new_entry;
375         FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry;
376
377         if (level == SMB_FIND_FILE_INFO_STANDARD) {
378                 FIND_FILE_STANDARD_INFO *pfData;
379                 pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo;
380
381                 new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) +
382                                 pfData->FileNameLength;
383         } else
384                 new_entry = old_entry + le32_to_cpu(pDirInfo->NextEntryOffset);
385         cifs_dbg(FYI, "new entry %p old entry %p\n", new_entry, old_entry);
386         /* validate that new_entry is not past end of SMB */
387         if (new_entry >= end_of_smb) {
388                 cifs_dbg(VFS, "search entry %p began after end of SMB %p old entry %p\n",
389                          new_entry, end_of_smb, old_entry);
390                 return NULL;
391         } else if (((level == SMB_FIND_FILE_INFO_STANDARD) &&
392                     (new_entry + sizeof(FIND_FILE_STANDARD_INFO) > end_of_smb))
393                   || ((level != SMB_FIND_FILE_INFO_STANDARD) &&
394                    (new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb)))  {
395                 cifs_dbg(VFS, "search entry %p extends after end of SMB %p\n",
396                          new_entry, end_of_smb);
397                 return NULL;
398         } else
399                 return new_entry;
400
401 }
402
403 struct cifs_dirent {
404         const char      *name;
405         size_t          namelen;
406         u32             resume_key;
407         u64             ino;
408 };
409
410 static void cifs_fill_dirent_unix(struct cifs_dirent *de,
411                 const FILE_UNIX_INFO *info, bool is_unicode)
412 {
413         de->name = &info->FileName[0];
414         if (is_unicode)
415                 de->namelen = cifs_unicode_bytelen(de->name);
416         else
417                 de->namelen = strnlen(de->name, PATH_MAX);
418         de->resume_key = info->ResumeKey;
419         de->ino = le64_to_cpu(info->basic.UniqueId);
420 }
421
422 static void cifs_fill_dirent_dir(struct cifs_dirent *de,
423                 const FILE_DIRECTORY_INFO *info)
424 {
425         de->name = &info->FileName[0];
426         de->namelen = le32_to_cpu(info->FileNameLength);
427         de->resume_key = info->FileIndex;
428 }
429
430 static void cifs_fill_dirent_full(struct cifs_dirent *de,
431                 const FILE_FULL_DIRECTORY_INFO *info)
432 {
433         de->name = &info->FileName[0];
434         de->namelen = le32_to_cpu(info->FileNameLength);
435         de->resume_key = info->FileIndex;
436 }
437
438 static void cifs_fill_dirent_search(struct cifs_dirent *de,
439                 const SEARCH_ID_FULL_DIR_INFO *info)
440 {
441         de->name = &info->FileName[0];
442         de->namelen = le32_to_cpu(info->FileNameLength);
443         de->resume_key = info->FileIndex;
444         de->ino = le64_to_cpu(info->UniqueId);
445 }
446
447 static void cifs_fill_dirent_both(struct cifs_dirent *de,
448                 const FILE_BOTH_DIRECTORY_INFO *info)
449 {
450         de->name = &info->FileName[0];
451         de->namelen = le32_to_cpu(info->FileNameLength);
452         de->resume_key = info->FileIndex;
453 }
454
455 static void cifs_fill_dirent_std(struct cifs_dirent *de,
456                 const FIND_FILE_STANDARD_INFO *info)
457 {
458         de->name = &info->FileName[0];
459         /* one byte length, no endianess conversion */
460         de->namelen = info->FileNameLength;
461         de->resume_key = info->ResumeKey;
462 }
463
464 static int cifs_fill_dirent(struct cifs_dirent *de, const void *info,
465                 u16 level, bool is_unicode)
466 {
467         memset(de, 0, sizeof(*de));
468
469         switch (level) {
470         case SMB_FIND_FILE_UNIX:
471                 cifs_fill_dirent_unix(de, info, is_unicode);
472                 break;
473         case SMB_FIND_FILE_DIRECTORY_INFO:
474                 cifs_fill_dirent_dir(de, info);
475                 break;
476         case SMB_FIND_FILE_FULL_DIRECTORY_INFO:
477                 cifs_fill_dirent_full(de, info);
478                 break;
479         case SMB_FIND_FILE_ID_FULL_DIR_INFO:
480                 cifs_fill_dirent_search(de, info);
481                 break;
482         case SMB_FIND_FILE_BOTH_DIRECTORY_INFO:
483                 cifs_fill_dirent_both(de, info);
484                 break;
485         case SMB_FIND_FILE_INFO_STANDARD:
486                 cifs_fill_dirent_std(de, info);
487                 break;
488         default:
489                 cifs_dbg(FYI, "Unknown findfirst level %d\n", level);
490                 return -EINVAL;
491         }
492
493         return 0;
494 }
495
496 #define UNICODE_DOT cpu_to_le16(0x2e)
497
498 /* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
499 static int cifs_entry_is_dot(struct cifs_dirent *de, bool is_unicode)
500 {
501         int rc = 0;
502
503         if (!de->name)
504                 return 0;
505
506         if (is_unicode) {
507                 __le16 *ufilename = (__le16 *)de->name;
508                 if (de->namelen == 2) {
509                         /* check for . */
510                         if (ufilename[0] == UNICODE_DOT)
511                                 rc = 1;
512                 } else if (de->namelen == 4) {
513                         /* check for .. */
514                         if (ufilename[0] == UNICODE_DOT &&
515                             ufilename[1] == UNICODE_DOT)
516                                 rc = 2;
517                 }
518         } else /* ASCII */ {
519                 if (de->namelen == 1) {
520                         if (de->name[0] == '.')
521                                 rc = 1;
522                 } else if (de->namelen == 2) {
523                         if (de->name[0] == '.' && de->name[1] == '.')
524                                 rc = 2;
525                 }
526         }
527
528         return rc;
529 }
530
531 /* Check if directory that we are searching has changed so we can decide
532    whether we can use the cached search results from the previous search */
533 static int is_dir_changed(struct file *file)
534 {
535         struct inode *inode = file_inode(file);
536         struct cifsInodeInfo *cifsInfo = CIFS_I(inode);
537
538         if (cifsInfo->time == 0)
539                 return 1; /* directory was changed, perhaps due to unlink */
540         else
541                 return 0;
542
543 }
544
545 static int cifs_save_resume_key(const char *current_entry,
546         struct cifsFileInfo *file_info)
547 {
548         struct cifs_dirent de;
549         int rc;
550
551         rc = cifs_fill_dirent(&de, current_entry, file_info->srch_inf.info_level,
552                               file_info->srch_inf.unicode);
553         if (!rc) {
554                 file_info->srch_inf.presume_name = de.name;
555                 file_info->srch_inf.resume_name_len = de.namelen;
556                 file_info->srch_inf.resume_key = de.resume_key;
557         }
558         return rc;
559 }
560
561 /*
562  * Find the corresponding entry in the search. Note that the SMB server returns
563  * search entries for . and .. which complicates logic here if we choose to
564  * parse for them and we do not assume that they are located in the findfirst
565  * return buffer. We start counting in the buffer with entry 2 and increment for
566  * every entry (do not increment for . or .. entry).
567  */
568 static int
569 find_cifs_entry(const unsigned int xid, struct cifs_tcon *tcon, loff_t pos,
570                 struct file *file, char **current_entry, int *num_to_ret)
571 {
572         __u16 search_flags;
573         int rc = 0;
574         int pos_in_buf = 0;
575         loff_t first_entry_in_buffer;
576         loff_t index_to_find = pos;
577         struct cifsFileInfo *cfile = file->private_data;
578         struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
579         struct TCP_Server_Info *server = tcon->ses->server;
580         /* check if index in the buffer */
581
582         if (!server->ops->query_dir_first || !server->ops->query_dir_next)
583                 return -ENOSYS;
584
585         if ((cfile == NULL) || (current_entry == NULL) || (num_to_ret == NULL))
586                 return -ENOENT;
587
588         *current_entry = NULL;
589         first_entry_in_buffer = cfile->srch_inf.index_of_last_entry -
590                                         cfile->srch_inf.entries_in_buffer;
591
592         /*
593          * If first entry in buf is zero then is first buffer
594          * in search response data which means it is likely . and ..
595          * will be in this buffer, although some servers do not return
596          * . and .. for the root of a drive and for those we need
597          * to start two entries earlier.
598          */
599
600         dump_cifs_file_struct(file, "In fce ");
601         if (((index_to_find < cfile->srch_inf.index_of_last_entry) &&
602              is_dir_changed(file)) || (index_to_find < first_entry_in_buffer)) {
603                 /* close and restart search */
604                 cifs_dbg(FYI, "search backing up - close and restart search\n");
605                 spin_lock(&cifs_file_list_lock);
606                 if (!cfile->srch_inf.endOfSearch && !cfile->invalidHandle) {
607                         cfile->invalidHandle = true;
608                         spin_unlock(&cifs_file_list_lock);
609                         if (server->ops->close)
610                                 server->ops->close(xid, tcon, &cfile->fid);
611                 } else
612                         spin_unlock(&cifs_file_list_lock);
613                 if (cfile->srch_inf.ntwrk_buf_start) {
614                         cifs_dbg(FYI, "freeing SMB ff cache buf on search rewind\n");
615                         if (cfile->srch_inf.smallBuf)
616                                 cifs_small_buf_release(cfile->srch_inf.
617                                                 ntwrk_buf_start);
618                         else
619                                 cifs_buf_release(cfile->srch_inf.
620                                                 ntwrk_buf_start);
621                         cfile->srch_inf.ntwrk_buf_start = NULL;
622                 }
623                 rc = initiate_cifs_search(xid, file);
624                 if (rc) {
625                         cifs_dbg(FYI, "error %d reinitiating a search on rewind\n",
626                                  rc);
627                         return rc;
628                 }
629                 /* FindFirst/Next set last_entry to NULL on malformed reply */
630                 if (cfile->srch_inf.last_entry)
631                         cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
632         }
633
634         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
635         if (backup_cred(cifs_sb))
636                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
637
638         while ((index_to_find >= cfile->srch_inf.index_of_last_entry) &&
639                (rc == 0) && !cfile->srch_inf.endOfSearch) {
640                 cifs_dbg(FYI, "calling findnext2\n");
641                 rc = server->ops->query_dir_next(xid, tcon, &cfile->fid,
642                                                  search_flags,
643                                                  &cfile->srch_inf);
644                 /* FindFirst/Next set last_entry to NULL on malformed reply */
645                 if (cfile->srch_inf.last_entry)
646                         cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
647                 if (rc)
648                         return -ENOENT;
649         }
650         if (index_to_find < cfile->srch_inf.index_of_last_entry) {
651                 /* we found the buffer that contains the entry */
652                 /* scan and find it */
653                 int i;
654                 char *cur_ent;
655                 char *end_of_smb = cfile->srch_inf.ntwrk_buf_start +
656                         server->ops->calc_smb_size(
657                                         cfile->srch_inf.ntwrk_buf_start);
658
659                 cur_ent = cfile->srch_inf.srch_entries_start;
660                 first_entry_in_buffer = cfile->srch_inf.index_of_last_entry
661                                         - cfile->srch_inf.entries_in_buffer;
662                 pos_in_buf = index_to_find - first_entry_in_buffer;
663                 cifs_dbg(FYI, "found entry - pos_in_buf %d\n", pos_in_buf);
664
665                 for (i = 0; (i < (pos_in_buf)) && (cur_ent != NULL); i++) {
666                         /* go entry by entry figuring out which is first */
667                         cur_ent = nxt_dir_entry(cur_ent, end_of_smb,
668                                                 cfile->srch_inf.info_level);
669                 }
670                 if ((cur_ent == NULL) && (i < pos_in_buf)) {
671                         /* BB fixme - check if we should flag this error */
672                         cifs_dbg(VFS, "reached end of buf searching for pos in buf %d index to find %lld rc %d\n",
673                                  pos_in_buf, index_to_find, rc);
674                 }
675                 rc = 0;
676                 *current_entry = cur_ent;
677         } else {
678                 cifs_dbg(FYI, "index not in buffer - could not findnext into it\n");
679                 return 0;
680         }
681
682         if (pos_in_buf >= cfile->srch_inf.entries_in_buffer) {
683                 cifs_dbg(FYI, "can not return entries pos_in_buf beyond last\n");
684                 *num_to_ret = 0;
685         } else
686                 *num_to_ret = cfile->srch_inf.entries_in_buffer - pos_in_buf;
687
688         return rc;
689 }
690
691 static int cifs_filldir(char *find_entry, struct file *file,
692                 struct dir_context *ctx,
693                 char *scratch_buf, unsigned int max_len)
694 {
695         struct cifsFileInfo *file_info = file->private_data;
696         struct super_block *sb = file->f_path.dentry->d_sb;
697         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
698         struct cifs_dirent de = { NULL, };
699         struct cifs_fattr fattr;
700         struct qstr name;
701         int rc = 0;
702         ino_t ino;
703
704         rc = cifs_fill_dirent(&de, find_entry, file_info->srch_inf.info_level,
705                               file_info->srch_inf.unicode);
706         if (rc)
707                 return rc;
708
709         if (de.namelen > max_len) {
710                 cifs_dbg(VFS, "bad search response length %zd past smb end\n",
711                          de.namelen);
712                 return -EINVAL;
713         }
714
715         /* skip . and .. since we added them first */
716         if (cifs_entry_is_dot(&de, file_info->srch_inf.unicode))
717                 return 0;
718
719         if (file_info->srch_inf.unicode) {
720                 struct nls_table *nlt = cifs_sb->local_nls;
721
722                 name.name = scratch_buf;
723                 name.len =
724                         cifs_from_utf16((char *)name.name, (__le16 *)de.name,
725                                         UNICODE_NAME_MAX,
726                                         min_t(size_t, de.namelen,
727                                               (size_t)max_len), nlt,
728                                         cifs_sb->mnt_cifs_flags &
729                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
730                 name.len -= nls_nullsize(nlt);
731         } else {
732                 name.name = de.name;
733                 name.len = de.namelen;
734         }
735
736         switch (file_info->srch_inf.info_level) {
737         case SMB_FIND_FILE_UNIX:
738                 cifs_unix_basic_to_fattr(&fattr,
739                                          &((FILE_UNIX_INFO *)find_entry)->basic,
740                                          cifs_sb);
741                 break;
742         case SMB_FIND_FILE_INFO_STANDARD:
743                 cifs_std_info_to_fattr(&fattr,
744                                        (FIND_FILE_STANDARD_INFO *)find_entry,
745                                        cifs_sb);
746                 break;
747         default:
748                 cifs_dir_info_to_fattr(&fattr,
749                                        (FILE_DIRECTORY_INFO *)find_entry,
750                                        cifs_sb);
751                 break;
752         }
753
754         if (de.ino && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
755                 fattr.cf_uniqueid = de.ino;
756         } else {
757                 fattr.cf_uniqueid = iunique(sb, ROOT_I);
758                 cifs_autodisable_serverino(cifs_sb);
759         }
760
761         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) &&
762             CIFSCouldBeMFSymlink(&fattr))
763                 /*
764                  * trying to get the type and mode can be slow,
765                  * so just call those regular files for now, and mark
766                  * for reval
767                  */
768                 fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
769
770         cifs_prime_dcache(file->f_dentry, &name, &fattr);
771
772         ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
773         return !dir_emit(ctx, name.name, name.len, ino, fattr.cf_dtype);
774 }
775
776
777 int cifs_readdir(struct file *file, struct dir_context *ctx)
778 {
779         int rc = 0;
780         unsigned int xid;
781         int i;
782         struct cifs_tcon *tcon;
783         struct cifsFileInfo *cifsFile = NULL;
784         char *current_entry;
785         int num_to_fill = 0;
786         char *tmp_buf = NULL;
787         char *end_of_smb;
788         unsigned int max_len;
789
790         xid = get_xid();
791
792         /*
793          * Ensure FindFirst doesn't fail before doing filldir() for '.' and
794          * '..'. Otherwise we won't be able to notify VFS in case of failure.
795          */
796         if (file->private_data == NULL) {
797                 rc = initiate_cifs_search(xid, file);
798                 cifs_dbg(FYI, "initiate cifs search rc %d\n", rc);
799                 if (rc)
800                         goto rddir2_exit;
801         }
802
803         if (!dir_emit_dots(file, ctx))
804                 goto rddir2_exit;
805
806         /* 1) If search is active,
807                 is in current search buffer?
808                 if it before then restart search
809                 if after then keep searching till find it */
810
811         if (file->private_data == NULL) {
812                 rc = -EINVAL;
813                 goto rddir2_exit;
814         }
815         cifsFile = file->private_data;
816         if (cifsFile->srch_inf.endOfSearch) {
817                 if (cifsFile->srch_inf.emptyDir) {
818                         cifs_dbg(FYI, "End of search, empty dir\n");
819                         rc = 0;
820                         goto rddir2_exit;
821                 }
822         } /* else {
823                 cifsFile->invalidHandle = true;
824                 tcon->ses->server->close(xid, tcon, &cifsFile->fid);
825         } */
826
827         tcon = tlink_tcon(cifsFile->tlink);
828         rc = find_cifs_entry(xid, tcon, ctx->pos, file, &current_entry,
829                              &num_to_fill);
830         if (rc) {
831                 cifs_dbg(FYI, "fce error %d\n", rc);
832                 goto rddir2_exit;
833         } else if (current_entry != NULL) {
834                 cifs_dbg(FYI, "entry %lld found\n", ctx->pos);
835         } else {
836                 cifs_dbg(FYI, "could not find entry\n");
837                 goto rddir2_exit;
838         }
839         cifs_dbg(FYI, "loop through %d times filling dir for net buf %p\n",
840                  num_to_fill, cifsFile->srch_inf.ntwrk_buf_start);
841         max_len = tcon->ses->server->ops->calc_smb_size(
842                         cifsFile->srch_inf.ntwrk_buf_start);
843         end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len;
844
845         tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL);
846         if (tmp_buf == NULL) {
847                 rc = -ENOMEM;
848                 goto rddir2_exit;
849         }
850
851         for (i = 0; i < num_to_fill; i++) {
852                 if (current_entry == NULL) {
853                         /* evaluate whether this case is an error */
854                         cifs_dbg(VFS, "past SMB end,  num to fill %d i %d\n",
855                                  num_to_fill, i);
856                         break;
857                 }
858                 /*
859                  * if buggy server returns . and .. late do we want to
860                  * check for that here?
861                  */
862                 rc = cifs_filldir(current_entry, file, ctx,
863                                   tmp_buf, max_len);
864                 if (rc) {
865                         if (rc > 0)
866                                 rc = 0;
867                         break;
868                 }
869
870                 ctx->pos++;
871                 if (ctx->pos ==
872                         cifsFile->srch_inf.index_of_last_entry) {
873                         cifs_dbg(FYI, "last entry in buf at pos %lld %s\n",
874                                  ctx->pos, tmp_buf);
875                         cifs_save_resume_key(current_entry, cifsFile);
876                         break;
877                 } else
878                         current_entry =
879                                 nxt_dir_entry(current_entry, end_of_smb,
880                                         cifsFile->srch_inf.info_level);
881         }
882         kfree(tmp_buf);
883
884 rddir2_exit:
885         free_xid(xid);
886         return rc;
887 }