[CIFS] Fix scheduling while atomic when pending writes at file close time
[linux-2.6] / fs / cifs / readdir.c
1 /*
2  *   fs/cifs/readdir.c
3  *
4  *   Directory search handling
5  * 
6  *   Copyright (C) International Business Machines  Corp., 2004, 2005
7  *   Author(s): Steve French (sfrench@us.ibm.com)
8  *
9  *   This library is free software; you can redistribute it and/or modify
10  *   it under the terms of the GNU Lesser General Public License as published
11  *   by the Free Software Foundation; either version 2.1 of the License, or
12  *   (at your option) any later version.
13  *
14  *   This library is distributed in the hope that it will be useful,
15  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
16  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
17  *   the GNU Lesser General Public License for more details.
18  *
19  *   You should have received a copy of the GNU Lesser General Public License
20  *   along with this library; if not, write to the Free Software
21  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22  */
23 #include <linux/fs.h>
24 #include <linux/stat.h>
25 #include <linux/smp_lock.h>
26 #include "cifspdu.h"
27 #include "cifsglob.h"
28 #include "cifsproto.h"
29 #include "cifs_unicode.h"
30 #include "cifs_debug.h"
31 #include "cifs_fs_sb.h"
32 #include "cifsfs.h"
33
34 /* BB fixme - add debug wrappers around this function to disable it fixme BB */
35 /* static void dump_cifs_file_struct(struct file *file, char *label)
36 {
37         struct cifsFileInfo * cf;
38
39         if(file) {
40                 cf = file->private_data;
41                 if(cf == NULL) {
42                         cFYI(1,("empty cifs private file data"));
43                         return;
44                 }
45                 if(cf->invalidHandle) {
46                         cFYI(1,("invalid handle"));
47                 }
48                 if(cf->srch_inf.endOfSearch) {
49                         cFYI(1,("end of search"));
50                 }
51                 if(cf->srch_inf.emptyDir) {
52                         cFYI(1,("empty dir"));
53                 }
54                 
55         }
56 } */
57
58 /* Returns one if new inode created (which therefore needs to be hashed) */
59 /* Might check in the future if inode number changed so we can rehash inode */
60 static int construct_dentry(struct qstr *qstring, struct file *file,
61         struct inode **ptmp_inode, struct dentry **pnew_dentry)
62 {
63         struct dentry *tmp_dentry;
64         struct cifs_sb_info *cifs_sb;
65         struct cifsTconInfo *pTcon;
66         int rc = 0;
67
68         cFYI(1, ("For %s", qstring->name));
69         cifs_sb = CIFS_SB(file->f_dentry->d_sb);
70         pTcon = cifs_sb->tcon;
71
72         qstring->hash = full_name_hash(qstring->name, qstring->len);
73         tmp_dentry = d_lookup(file->f_dentry, qstring);
74         if (tmp_dentry) {
75                 cFYI(0, ("existing dentry with inode 0x%p", tmp_dentry->d_inode));
76                 *ptmp_inode = tmp_dentry->d_inode;
77 /* BB overwrite old name? i.e. tmp_dentry->d_name and tmp_dentry->d_name.len??*/
78                 if(*ptmp_inode == NULL) {
79                         *ptmp_inode = new_inode(file->f_dentry->d_sb);
80                         if(*ptmp_inode == NULL)
81                                 return rc;
82                         rc = 1;
83                         d_instantiate(tmp_dentry, *ptmp_inode);
84                 }
85         } else {
86                 tmp_dentry = d_alloc(file->f_dentry, qstring);
87                 if(tmp_dentry == NULL) {
88                         cERROR(1,("Failed allocating dentry"));
89                         *ptmp_inode = NULL;
90                         return rc;
91                 }
92
93                 *ptmp_inode = new_inode(file->f_dentry->d_sb);
94                 if (pTcon->nocase)
95                         tmp_dentry->d_op = &cifs_ci_dentry_ops;
96                 else
97                         tmp_dentry->d_op = &cifs_dentry_ops;
98                 if(*ptmp_inode == NULL)
99                         return rc;
100                 rc = 1;
101                 d_instantiate(tmp_dentry, *ptmp_inode);
102                 d_rehash(tmp_dentry);
103         }
104
105         tmp_dentry->d_time = jiffies;
106         *pnew_dentry = tmp_dentry;
107         return rc;
108 }
109
110 static void fill_in_inode(struct inode *tmp_inode,
111         FILE_DIRECTORY_INFO *pfindData, int *pobject_type, int isNewInode)
112 {
113         loff_t local_size;
114         struct timespec local_mtime;
115
116         struct cifsInodeInfo *cifsInfo = CIFS_I(tmp_inode);
117         struct cifs_sb_info *cifs_sb = CIFS_SB(tmp_inode->i_sb);
118         __u32 attr = le32_to_cpu(pfindData->ExtFileAttributes);
119         __u64 allocation_size = le64_to_cpu(pfindData->AllocationSize);
120         __u64 end_of_file = le64_to_cpu(pfindData->EndOfFile);
121
122         cifsInfo->cifsAttrs = attr;
123         cifsInfo->time = jiffies;
124
125         /* save mtime and size */
126         local_mtime = tmp_inode->i_mtime;
127         local_size  = tmp_inode->i_size;
128
129         /* Linux can not store file creation time unfortunately so ignore it */
130         tmp_inode->i_atime =
131             cifs_NTtimeToUnix(le64_to_cpu(pfindData->LastAccessTime));
132         tmp_inode->i_mtime =
133             cifs_NTtimeToUnix(le64_to_cpu(pfindData->LastWriteTime));
134         tmp_inode->i_ctime =
135             cifs_NTtimeToUnix(le64_to_cpu(pfindData->ChangeTime));
136         /* treat dos attribute of read-only as read-only mode bit e.g. 555? */
137         /* 2767 perms - indicate mandatory locking */
138                 /* BB fill in uid and gid here? with help from winbind? 
139                    or retrieve from NTFS stream extended attribute */
140         if (atomic_read(&cifsInfo->inUse) == 0) {
141                 tmp_inode->i_uid = cifs_sb->mnt_uid;
142                 tmp_inode->i_gid = cifs_sb->mnt_gid;
143                 /* set default mode. will override for dirs below */
144                 tmp_inode->i_mode = cifs_sb->mnt_file_mode;
145         } else {
146                 /* mask off the type bits since it gets set
147                 below and we do not want to get two type
148                 bits set */
149                 tmp_inode->i_mode &= ~S_IFMT;
150         }
151
152         if (attr & ATTR_DIRECTORY) {
153                 *pobject_type = DT_DIR;
154                 /* override default perms since we do not lock dirs */
155                 if(atomic_read(&cifsInfo->inUse) == 0) {
156                         tmp_inode->i_mode = cifs_sb->mnt_dir_mode;
157                 }
158                 tmp_inode->i_mode |= S_IFDIR;
159         } else if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) && 
160                    (attr & ATTR_SYSTEM)) {
161                 if (end_of_file == 0)  {
162                         *pobject_type = DT_FIFO;
163                         tmp_inode->i_mode |= S_IFIFO;
164                 } else {
165                         /* rather than get the type here, we mark the
166                         inode as needing revalidate and get the real type
167                         (blk vs chr vs. symlink) later ie in lookup */
168                         *pobject_type = DT_REG;
169                         tmp_inode->i_mode |= S_IFREG; 
170                         cifsInfo->time = 0;     
171                 }
172 /* we no longer mark these because we could not follow them */
173 /*        } else if (attr & ATTR_REPARSE) {
174                 *pobject_type = DT_LNK;
175                 tmp_inode->i_mode |= S_IFLNK; */
176         } else {
177                 *pobject_type = DT_REG;
178                 tmp_inode->i_mode |= S_IFREG;
179                 if (attr & ATTR_READONLY)
180                         tmp_inode->i_mode &= ~(S_IWUGO);
181         } /* could add code here - to validate if device or weird share type? */
182
183         /* can not fill in nlink here as in qpathinfo version and Unx search */
184         if (atomic_read(&cifsInfo->inUse) == 0) {
185                 atomic_set(&cifsInfo->inUse, 1);
186         }
187
188         if (is_size_safe_to_change(cifsInfo)) {
189                 /* can not safely change the file size here if the 
190                 client is writing to it due to potential races */
191                 i_size_write(tmp_inode, end_of_file);
192
193         /* 512 bytes (2**9) is the fake blocksize that must be used */
194         /* for this calculation, even though the reported blocksize is larger */
195                 tmp_inode->i_blocks = (512 - 1 + allocation_size) >> 9;
196         }
197
198         if (allocation_size < end_of_file)
199                 cFYI(1, ("May be sparse file, allocation less than file size"));
200         cFYI(1,
201              ("File Size %ld and blocks %ld and blocksize %ld",
202               (unsigned long)tmp_inode->i_size, tmp_inode->i_blocks,
203               tmp_inode->i_blksize));
204         if (S_ISREG(tmp_inode->i_mode)) {
205                 cFYI(1, ("File inode"));
206                 tmp_inode->i_op = &cifs_file_inode_ops;
207                 if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO) {
208                         if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
209                                 tmp_inode->i_fop = &cifs_file_direct_nobrl_ops;
210                         else
211                                 tmp_inode->i_fop = &cifs_file_direct_ops;
212                 
213                 } else if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
214                         tmp_inode->i_fop = &cifs_file_nobrl_ops;
215                 else
216                         tmp_inode->i_fop = &cifs_file_ops;
217                 if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
218                         tmp_inode->i_fop->lock = NULL;
219                 tmp_inode->i_data.a_ops = &cifs_addr_ops;
220                 if((cifs_sb->tcon) && (cifs_sb->tcon->ses) &&
221                    (cifs_sb->tcon->ses->server->maxBuf <
222                         4096 + MAX_CIFS_HDR_SIZE))
223                         tmp_inode->i_data.a_ops->readpages = NULL;
224                 if(isNewInode)
225                         return; /* No sense invalidating pages for new inode
226                                    since have not started caching readahead file
227                                    data yet */
228
229                 if (timespec_equal(&tmp_inode->i_mtime, &local_mtime) &&
230                         (local_size == tmp_inode->i_size)) {
231                         cFYI(1, ("inode exists but unchanged"));
232                 } else {
233                         /* file may have changed on server */
234                         cFYI(1, ("invalidate inode, readdir detected change"));
235                         invalidate_remote_inode(tmp_inode);
236                 }
237         } else if (S_ISDIR(tmp_inode->i_mode)) {
238                 cFYI(1, ("Directory inode"));
239                 tmp_inode->i_op = &cifs_dir_inode_ops;
240                 tmp_inode->i_fop = &cifs_dir_ops;
241         } else if (S_ISLNK(tmp_inode->i_mode)) {
242                 cFYI(1, ("Symbolic Link inode"));
243                 tmp_inode->i_op = &cifs_symlink_inode_ops;
244         } else {
245                 cFYI(1, ("Init special inode"));
246                 init_special_inode(tmp_inode, tmp_inode->i_mode,
247                                    tmp_inode->i_rdev);
248         }
249 }
250
251 static void unix_fill_in_inode(struct inode *tmp_inode,
252         FILE_UNIX_INFO *pfindData, int *pobject_type, int isNewInode)
253 {
254         loff_t local_size;
255         struct timespec local_mtime;
256
257         struct cifsInodeInfo *cifsInfo = CIFS_I(tmp_inode);
258         struct cifs_sb_info *cifs_sb = CIFS_SB(tmp_inode->i_sb);
259
260         __u32 type = le32_to_cpu(pfindData->Type);
261         __u64 num_of_bytes = le64_to_cpu(pfindData->NumOfBytes);
262         __u64 end_of_file = le64_to_cpu(pfindData->EndOfFile);
263         cifsInfo->time = jiffies;
264         atomic_inc(&cifsInfo->inUse);
265
266         /* save mtime and size */
267         local_mtime = tmp_inode->i_mtime;
268         local_size  = tmp_inode->i_size;
269
270         tmp_inode->i_atime =
271             cifs_NTtimeToUnix(le64_to_cpu(pfindData->LastAccessTime));
272         tmp_inode->i_mtime =
273             cifs_NTtimeToUnix(le64_to_cpu(pfindData->LastModificationTime));
274         tmp_inode->i_ctime =
275             cifs_NTtimeToUnix(le64_to_cpu(pfindData->LastStatusChange));
276
277         tmp_inode->i_mode = le64_to_cpu(pfindData->Permissions);
278         /* since we set the inode type below we need to mask off type
279            to avoid strange results if bits above were corrupt */
280         tmp_inode->i_mode &= ~S_IFMT;
281         if (type == UNIX_FILE) {
282                 *pobject_type = DT_REG;
283                 tmp_inode->i_mode |= S_IFREG;
284         } else if (type == UNIX_SYMLINK) {
285                 *pobject_type = DT_LNK;
286                 tmp_inode->i_mode |= S_IFLNK;
287         } else if (type == UNIX_DIR) {
288                 *pobject_type = DT_DIR;
289                 tmp_inode->i_mode |= S_IFDIR;
290         } else if (type == UNIX_CHARDEV) {
291                 *pobject_type = DT_CHR;
292                 tmp_inode->i_mode |= S_IFCHR;
293                 tmp_inode->i_rdev = MKDEV(le64_to_cpu(pfindData->DevMajor),
294                                 le64_to_cpu(pfindData->DevMinor) & MINORMASK);
295         } else if (type == UNIX_BLOCKDEV) {
296                 *pobject_type = DT_BLK;
297                 tmp_inode->i_mode |= S_IFBLK;
298                 tmp_inode->i_rdev = MKDEV(le64_to_cpu(pfindData->DevMajor),
299                                 le64_to_cpu(pfindData->DevMinor) & MINORMASK);
300         } else if (type == UNIX_FIFO) {
301                 *pobject_type = DT_FIFO;
302                 tmp_inode->i_mode |= S_IFIFO;
303         } else if (type == UNIX_SOCKET) {
304                 *pobject_type = DT_SOCK;
305                 tmp_inode->i_mode |= S_IFSOCK;
306         } else {
307                 /* safest to just call it a file */
308                 *pobject_type = DT_REG;
309                 tmp_inode->i_mode |= S_IFREG;
310                 cFYI(1,("unknown inode type %d",type)); 
311         }
312
313         tmp_inode->i_uid = le64_to_cpu(pfindData->Uid);
314         tmp_inode->i_gid = le64_to_cpu(pfindData->Gid);
315         tmp_inode->i_nlink = le64_to_cpu(pfindData->Nlinks);
316
317         if (is_size_safe_to_change(cifsInfo)) {
318                 /* can not safely change the file size here if the 
319                 client is writing to it due to potential races */
320                 i_size_write(tmp_inode,end_of_file);
321
322         /* 512 bytes (2**9) is the fake blocksize that must be used */
323         /* for this calculation, not the real blocksize */
324                 tmp_inode->i_blocks = (512 - 1 + num_of_bytes) >> 9;
325         }
326
327         if (S_ISREG(tmp_inode->i_mode)) {
328                 cFYI(1, ("File inode"));
329                 tmp_inode->i_op = &cifs_file_inode_ops;
330                 if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO)
331                         tmp_inode->i_fop = &cifs_file_direct_ops;
332                 else
333                         tmp_inode->i_fop = &cifs_file_ops;
334                 if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
335                         tmp_inode->i_fop->lock = NULL;
336                 tmp_inode->i_data.a_ops = &cifs_addr_ops;
337                 if((cifs_sb->tcon) && (cifs_sb->tcon->ses) &&
338                    (cifs_sb->tcon->ses->server->maxBuf < 
339                         4096 + MAX_CIFS_HDR_SIZE))
340                         tmp_inode->i_data.a_ops->readpages = NULL;
341
342                 if(isNewInode)
343                         return; /* No sense invalidating pages for new inode since we
344                                            have not started caching readahead file data yet */
345
346                 if (timespec_equal(&tmp_inode->i_mtime, &local_mtime) &&
347                         (local_size == tmp_inode->i_size)) {
348                         cFYI(1, ("inode exists but unchanged"));
349                 } else {
350                         /* file may have changed on server */
351                         cFYI(1, ("invalidate inode, readdir detected change"));
352                         invalidate_remote_inode(tmp_inode);
353                 }
354         } else if (S_ISDIR(tmp_inode->i_mode)) {
355                 cFYI(1, ("Directory inode"));
356                 tmp_inode->i_op = &cifs_dir_inode_ops;
357                 tmp_inode->i_fop = &cifs_dir_ops;
358         } else if (S_ISLNK(tmp_inode->i_mode)) {
359                 cFYI(1, ("Symbolic Link inode"));
360                 tmp_inode->i_op = &cifs_symlink_inode_ops;
361 /* tmp_inode->i_fop = *//* do not need to set to anything */
362         } else {
363                 cFYI(1, ("Special inode")); 
364                 init_special_inode(tmp_inode, tmp_inode->i_mode,
365                                    tmp_inode->i_rdev);
366         }
367 }
368
369 static int initiate_cifs_search(const int xid, struct file *file)
370 {
371         int rc = 0;
372         char * full_path;
373         struct cifsFileInfo * cifsFile;
374         struct cifs_sb_info *cifs_sb;
375         struct cifsTconInfo *pTcon;
376
377         if(file->private_data == NULL) {
378                 file->private_data = 
379                         kmalloc(sizeof(struct cifsFileInfo),GFP_KERNEL);
380         }
381
382         if(file->private_data == NULL) {
383                 return -ENOMEM;
384         } else {
385                 memset(file->private_data,0,sizeof(struct cifsFileInfo));
386         }
387         cifsFile = file->private_data;
388         cifsFile->invalidHandle = TRUE;
389         cifsFile->srch_inf.endOfSearch = FALSE;
390
391         if(file->f_dentry == NULL)
392                 return -ENOENT;
393
394         cifs_sb = CIFS_SB(file->f_dentry->d_sb);
395         if(cifs_sb == NULL)
396                 return -EINVAL;
397
398         pTcon = cifs_sb->tcon;
399         if(pTcon == NULL)
400                 return -EINVAL;
401
402         down(&file->f_dentry->d_sb->s_vfs_rename_sem);
403         full_path = build_path_from_dentry(file->f_dentry);
404         up(&file->f_dentry->d_sb->s_vfs_rename_sem);
405
406         if(full_path == NULL) {
407                 return -ENOMEM;
408         }
409
410         cFYI(1, ("Full path: %s start at: %lld", full_path, file->f_pos));
411
412 ffirst_retry:
413         /* test for Unix extensions */
414         if (pTcon->ses->capabilities & CAP_UNIX) {
415                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX; 
416         } else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
417                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
418         } else /* not srvinos - BB fixme add check for backlevel? */ {
419                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_DIRECTORY_INFO;
420         }
421
422         rc = CIFSFindFirst(xid, pTcon,full_path,cifs_sb->local_nls,
423                 &cifsFile->netfid, &cifsFile->srch_inf,
424                 cifs_sb->mnt_cifs_flags & 
425                         CIFS_MOUNT_MAP_SPECIAL_CHR, CIFS_DIR_SEP(cifs_sb));
426         if(rc == 0)
427                 cifsFile->invalidHandle = FALSE;
428         if((rc == -EOPNOTSUPP) && 
429                 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
430                 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
431                 goto ffirst_retry;
432         }
433         kfree(full_path);
434         return rc;
435 }
436
437 /* return length of unicode string in bytes */
438 static int cifs_unicode_bytelen(char *str)
439 {
440         int len;
441         __le16 * ustr = (__le16 *)str;
442
443         for(len=0;len <= PATH_MAX;len++) {
444                 if(ustr[len] == 0)
445                         return len << 1;
446         }
447         cFYI(1,("Unicode string longer than PATH_MAX found"));
448         return len << 1;
449 }
450
451 static char *nxt_dir_entry(char *old_entry, char *end_of_smb)
452 {
453         char * new_entry;
454         FILE_DIRECTORY_INFO * pDirInfo = (FILE_DIRECTORY_INFO *)old_entry;
455
456         new_entry = old_entry + le32_to_cpu(pDirInfo->NextEntryOffset);
457         cFYI(1,("new entry %p old entry %p",new_entry,old_entry));
458         /* validate that new_entry is not past end of SMB */
459         if(new_entry >= end_of_smb) {
460                 cERROR(1,
461                       ("search entry %p began after end of SMB %p old entry %p",
462                         new_entry, end_of_smb, old_entry)); 
463                 return NULL;
464         } else if (new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb) {
465                 cERROR(1,("search entry %p extends after end of SMB %p",
466                         new_entry, end_of_smb));
467                 return NULL;
468         } else 
469                 return new_entry;
470
471 }
472
473 #define UNICODE_DOT cpu_to_le16(0x2e)
474
475 /* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
476 static int cifs_entry_is_dot(char *current_entry, struct cifsFileInfo *cfile)
477 {
478         int rc = 0;
479         char * filename = NULL;
480         int len = 0; 
481
482         if(cfile->srch_inf.info_level == 0x202) {
483                 FILE_UNIX_INFO * pFindData = (FILE_UNIX_INFO *)current_entry;
484                 filename = &pFindData->FileName[0];
485                 if(cfile->srch_inf.unicode) {
486                         len = cifs_unicode_bytelen(filename);
487                 } else {
488                         /* BB should we make this strnlen of PATH_MAX? */
489                         len = strnlen(filename, 5);
490                 }
491         } else if(cfile->srch_inf.info_level == 0x101) {
492                 FILE_DIRECTORY_INFO * pFindData = 
493                         (FILE_DIRECTORY_INFO *)current_entry;
494                 filename = &pFindData->FileName[0];
495                 len = le32_to_cpu(pFindData->FileNameLength);
496         } else if(cfile->srch_inf.info_level == 0x102) {
497                 FILE_FULL_DIRECTORY_INFO * pFindData = 
498                         (FILE_FULL_DIRECTORY_INFO *)current_entry;
499                 filename = &pFindData->FileName[0];
500                 len = le32_to_cpu(pFindData->FileNameLength);
501         } else if(cfile->srch_inf.info_level == 0x105) {
502                 SEARCH_ID_FULL_DIR_INFO * pFindData = 
503                         (SEARCH_ID_FULL_DIR_INFO *)current_entry;
504                 filename = &pFindData->FileName[0];
505                 len = le32_to_cpu(pFindData->FileNameLength);
506         } else if(cfile->srch_inf.info_level == 0x104) {
507                 FILE_BOTH_DIRECTORY_INFO * pFindData = 
508                         (FILE_BOTH_DIRECTORY_INFO *)current_entry;
509                 filename = &pFindData->FileName[0];
510                 len = le32_to_cpu(pFindData->FileNameLength);
511         } else {
512                 cFYI(1,("Unknown findfirst level %d",cfile->srch_inf.info_level));
513         }
514
515         if(filename) {
516                 if(cfile->srch_inf.unicode) {
517                         __le16 *ufilename = (__le16 *)filename;
518                         if(len == 2) {
519                                 /* check for . */
520                                 if(ufilename[0] == UNICODE_DOT)
521                                         rc = 1;
522                         } else if(len == 4) {
523                                 /* check for .. */
524                                 if((ufilename[0] == UNICODE_DOT)
525                                    &&(ufilename[1] == UNICODE_DOT))
526                                         rc = 2;
527                         }
528                 } else /* ASCII */ {
529                         if(len == 1) {
530                                 if(filename[0] == '.') 
531                                         rc = 1;
532                         } else if(len == 2) {
533                                 if((filename[0] == '.') && (filename[1] == '.')) 
534                                         rc = 2;
535                         }
536                 }
537         }
538
539         return rc;
540 }
541
542 /* Check if directory that we are searching has changed so we can decide
543    whether we can use the cached search results from the previous search */
544 static int is_dir_changed(struct file * file)
545 {
546         struct inode * inode;
547         struct cifsInodeInfo *cifsInfo;
548
549         if(file->f_dentry == NULL)
550                 return 0;
551
552         inode = file->f_dentry->d_inode;
553
554         if(inode == NULL)
555                 return 0;
556
557         cifsInfo = CIFS_I(inode);
558
559         if(cifsInfo->time == 0)
560                 return 1; /* directory was changed, perhaps due to unlink */
561         else
562                 return 0;
563
564 }
565
566 /* find the corresponding entry in the search */
567 /* Note that the SMB server returns search entries for . and .. which
568    complicates logic here if we choose to parse for them and we do not
569    assume that they are located in the findfirst return buffer.*/
570 /* We start counting in the buffer with entry 2 and increment for every
571    entry (do not increment for . or .. entry) */
572 static int find_cifs_entry(const int xid, struct cifsTconInfo *pTcon,
573         struct file *file, char **ppCurrentEntry, int *num_to_ret) 
574 {
575         int rc = 0;
576         int pos_in_buf = 0;
577         loff_t first_entry_in_buffer;
578         loff_t index_to_find = file->f_pos;
579         struct cifsFileInfo * cifsFile = file->private_data;
580         /* check if index in the buffer */
581         
582         if((cifsFile == NULL) || (ppCurrentEntry == NULL) || 
583            (num_to_ret == NULL))
584                 return -ENOENT;
585         
586         *ppCurrentEntry = NULL;
587         first_entry_in_buffer = 
588                 cifsFile->srch_inf.index_of_last_entry - 
589                         cifsFile->srch_inf.entries_in_buffer;
590 /*      dump_cifs_file_struct(file, "In fce ");*/
591         if(((index_to_find < cifsFile->srch_inf.index_of_last_entry) && 
592              is_dir_changed(file)) || 
593            (index_to_find < first_entry_in_buffer)) {
594                 /* close and restart search */
595                 cFYI(1,("search backing up - close and restart search"));
596                 cifsFile->invalidHandle = TRUE;
597                 CIFSFindClose(xid, pTcon, cifsFile->netfid);
598                 kfree(cifsFile->search_resume_name);
599                 cifsFile->search_resume_name = NULL;
600                 if(cifsFile->srch_inf.ntwrk_buf_start) {
601                         cFYI(1,("freeing SMB ff cache buf on search rewind"));
602                         cifs_buf_release(cifsFile->srch_inf.ntwrk_buf_start);
603                 }
604                 rc = initiate_cifs_search(xid,file);
605                 if(rc) {
606                         cFYI(1,("error %d reinitiating a search on rewind",rc));
607                         return rc;
608                 }
609         }
610
611         while((index_to_find >= cifsFile->srch_inf.index_of_last_entry) && 
612               (rc == 0) && (cifsFile->srch_inf.endOfSearch == FALSE)){
613                 cFYI(1,("calling findnext2"));
614                 rc = CIFSFindNext(xid,pTcon,cifsFile->netfid, 
615                                   &cifsFile->srch_inf);
616                 if(rc)
617                         return -ENOENT;
618         }
619         if(index_to_find < cifsFile->srch_inf.index_of_last_entry) {
620                 /* we found the buffer that contains the entry */
621                 /* scan and find it */
622                 int i;
623                 char * current_entry;
624                 char * end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + 
625                         smbCalcSize((struct smb_hdr *)
626                                 cifsFile->srch_inf.ntwrk_buf_start);
627                 first_entry_in_buffer = cifsFile->srch_inf.index_of_last_entry
628                                         - cifsFile->srch_inf.entries_in_buffer;
629                 pos_in_buf = index_to_find - first_entry_in_buffer;
630                 cFYI(1,("found entry - pos_in_buf %d",pos_in_buf)); 
631                 current_entry = cifsFile->srch_inf.srch_entries_start;
632                 for(i=0;(i<(pos_in_buf)) && (current_entry != NULL);i++) {
633                         /* go entry by entry figuring out which is first */
634                         /* if( . or ..)
635                                 skip */
636                         rc = cifs_entry_is_dot(current_entry,cifsFile);
637                         if(rc == 1) /* is . or .. so skip */ {
638                                 cFYI(1,("Entry is .")); /* BB removeme BB */
639                                 /* continue; */
640                         } else if (rc == 2 ) {
641                                 cFYI(1,("Entry is ..")); /* BB removeme BB */
642                                 /* continue; */
643                         }
644                         current_entry = nxt_dir_entry(current_entry,end_of_smb);
645                 }
646                 if((current_entry == NULL) && (i < pos_in_buf)) {
647                         /* BB fixme - check if we should flag this error */
648                         cERROR(1,("reached end of buf searching for pos in buf"
649                           " %d index to find %lld rc %d",
650                           pos_in_buf,index_to_find,rc));
651                 }
652                 rc = 0;
653                 *ppCurrentEntry = current_entry;
654         } else {
655                 cFYI(1,("index not in buffer - could not findnext into it"));
656                 return 0;
657         }
658
659         if(pos_in_buf >= cifsFile->srch_inf.entries_in_buffer) {
660                 cFYI(1,("can not return entries pos_in_buf beyond last entry"));
661                 *num_to_ret = 0;
662         } else
663                 *num_to_ret = cifsFile->srch_inf.entries_in_buffer - pos_in_buf;
664
665         return rc;
666 }
667
668 /* inode num, inode type and filename returned */
669 static int cifs_get_name_from_search_buf(struct qstr *pqst,
670         char *current_entry, __u16 level, unsigned int unicode,
671         struct cifs_sb_info * cifs_sb, ino_t *pinum)
672 {
673         int rc = 0;
674         unsigned int len = 0;
675         char * filename;
676         struct nls_table * nlt = cifs_sb->local_nls;
677
678         *pinum = 0;
679
680         if(level == SMB_FIND_FILE_UNIX) {
681                 FILE_UNIX_INFO * pFindData = (FILE_UNIX_INFO *)current_entry;
682
683                 filename = &pFindData->FileName[0];
684                 if(unicode) {
685                         len = cifs_unicode_bytelen(filename);
686                 } else {
687                         /* BB should we make this strnlen of PATH_MAX? */
688                         len = strnlen(filename, PATH_MAX);
689                 }
690
691                 /* BB fixme - hash low and high 32 bits if not 64 bit arch BB fixme */
692                 if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)
693                         *pinum = pFindData->UniqueId;
694         } else if(level == SMB_FIND_FILE_DIRECTORY_INFO) {
695                 FILE_DIRECTORY_INFO * pFindData = 
696                         (FILE_DIRECTORY_INFO *)current_entry;
697                 filename = &pFindData->FileName[0];
698                 len = le32_to_cpu(pFindData->FileNameLength);
699         } else if(level == SMB_FIND_FILE_FULL_DIRECTORY_INFO) {
700                 FILE_FULL_DIRECTORY_INFO * pFindData = 
701                         (FILE_FULL_DIRECTORY_INFO *)current_entry;
702                 filename = &pFindData->FileName[0];
703                 len = le32_to_cpu(pFindData->FileNameLength);
704         } else if(level == SMB_FIND_FILE_ID_FULL_DIR_INFO) {
705                 SEARCH_ID_FULL_DIR_INFO * pFindData = 
706                         (SEARCH_ID_FULL_DIR_INFO *)current_entry;
707                 filename = &pFindData->FileName[0];
708                 len = le32_to_cpu(pFindData->FileNameLength);
709                 *pinum = pFindData->UniqueId;
710         } else if(level == SMB_FIND_FILE_BOTH_DIRECTORY_INFO) {
711                 FILE_BOTH_DIRECTORY_INFO * pFindData = 
712                         (FILE_BOTH_DIRECTORY_INFO *)current_entry;
713                 filename = &pFindData->FileName[0];
714                 len = le32_to_cpu(pFindData->FileNameLength);
715         } else {
716                 cFYI(1,("Unknown findfirst level %d",level));
717                 return -EINVAL;
718         }
719         if(unicode) {
720                 /* BB fixme - test with long names */
721                 /* Note converted filename can be longer than in unicode */
722                 if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR)
723                         pqst->len = cifs_convertUCSpath((char *)pqst->name,
724                                         (__le16 *)filename, len/2, nlt);
725                 else
726                         pqst->len = cifs_strfromUCS_le((char *)pqst->name,
727                                         (__le16 *)filename,len/2,nlt);
728         } else {
729                 pqst->name = filename;
730                 pqst->len = len;
731         }
732         pqst->hash = full_name_hash(pqst->name,pqst->len);
733 /*      cFYI(1,("filldir on %s",pqst->name));  */
734         return rc;
735 }
736
737 static int cifs_filldir(char *pfindEntry, struct file *file,
738         filldir_t filldir, void *direntry, char *scratch_buf)
739 {
740         int rc = 0;
741         struct qstr qstring;
742         struct cifsFileInfo * pCifsF;
743         unsigned obj_type;
744         ino_t  inum;
745         struct cifs_sb_info * cifs_sb;
746         struct inode *tmp_inode;
747         struct dentry *tmp_dentry;
748
749         /* get filename and len into qstring */
750         /* get dentry */
751         /* decide whether to create and populate ionde */
752         if((direntry == NULL) || (file == NULL))
753                 return -EINVAL;
754
755         pCifsF = file->private_data;
756         
757         if((scratch_buf == NULL) || (pfindEntry == NULL) || (pCifsF == NULL))
758                 return -ENOENT;
759
760         if(file->f_dentry == NULL)
761                 return -ENOENT;
762
763         cifs_sb = CIFS_SB(file->f_dentry->d_sb);
764
765         qstring.name = scratch_buf;
766         rc = cifs_get_name_from_search_buf(&qstring,pfindEntry,
767                         pCifsF->srch_inf.info_level,
768                         pCifsF->srch_inf.unicode,cifs_sb,
769                         &inum /* returned */);
770
771         if(rc)
772                 return rc;
773
774         rc = construct_dentry(&qstring,file,&tmp_inode, &tmp_dentry);
775         if((tmp_inode == NULL) || (tmp_dentry == NULL))
776                 return -ENOMEM;
777
778         if(rc) {
779                 /* inode created, we need to hash it with right inode number */
780                 if(inum != 0) {
781                         /* BB fixme - hash the 2 32 quantities bits together if necessary BB */
782                         tmp_inode->i_ino = inum;
783                 }
784                 insert_inode_hash(tmp_inode);
785         }
786
787         /* we pass in rc below, indicating whether it is a new inode,
788            so we can figure out whether to invalidate the inode cached
789            data if the file has changed */
790         if(pCifsF->srch_inf.info_level == SMB_FIND_FILE_UNIX) {
791                 unix_fill_in_inode(tmp_inode,
792                                    (FILE_UNIX_INFO *)pfindEntry,&obj_type, rc);
793         } else {
794                 fill_in_inode(tmp_inode,
795                               (FILE_DIRECTORY_INFO *)pfindEntry,&obj_type, rc);
796         }
797         
798         rc = filldir(direntry,qstring.name,qstring.len,file->f_pos,
799                      tmp_inode->i_ino,obj_type);
800         if(rc) {
801                 cFYI(1,("filldir rc = %d",rc));
802         }
803
804         dput(tmp_dentry);
805         return rc;
806 }
807
808 static int cifs_save_resume_key(const char *current_entry,
809         struct cifsFileInfo *cifsFile)
810 {
811         int rc = 0;
812         unsigned int len = 0;
813         __u16 level;
814         char * filename;
815
816         if((cifsFile == NULL) || (current_entry == NULL))
817                 return -EINVAL;
818
819         level = cifsFile->srch_inf.info_level;
820
821         if(level == SMB_FIND_FILE_UNIX) {
822                 FILE_UNIX_INFO * pFindData = (FILE_UNIX_INFO *)current_entry;
823
824                 filename = &pFindData->FileName[0];
825                 if(cifsFile->srch_inf.unicode) {
826                         len = cifs_unicode_bytelen(filename);
827                 } else {
828                         /* BB should we make this strnlen of PATH_MAX? */
829                         len = strnlen(filename, PATH_MAX);
830                 }
831                 cifsFile->srch_inf.resume_key = pFindData->ResumeKey;
832         } else if(level == SMB_FIND_FILE_DIRECTORY_INFO) {
833                 FILE_DIRECTORY_INFO * pFindData = 
834                         (FILE_DIRECTORY_INFO *)current_entry;
835                 filename = &pFindData->FileName[0];
836                 len = le32_to_cpu(pFindData->FileNameLength);
837                 cifsFile->srch_inf.resume_key = pFindData->FileIndex;
838         } else if(level == SMB_FIND_FILE_FULL_DIRECTORY_INFO) {
839                 FILE_FULL_DIRECTORY_INFO * pFindData = 
840                         (FILE_FULL_DIRECTORY_INFO *)current_entry;
841                 filename = &pFindData->FileName[0];
842                 len = le32_to_cpu(pFindData->FileNameLength);
843                 cifsFile->srch_inf.resume_key = pFindData->FileIndex;
844         } else if(level == SMB_FIND_FILE_ID_FULL_DIR_INFO) {
845                 SEARCH_ID_FULL_DIR_INFO * pFindData = 
846                         (SEARCH_ID_FULL_DIR_INFO *)current_entry;
847                 filename = &pFindData->FileName[0];
848                 len = le32_to_cpu(pFindData->FileNameLength);
849                 cifsFile->srch_inf.resume_key = pFindData->FileIndex;
850         } else if(level == SMB_FIND_FILE_BOTH_DIRECTORY_INFO) {
851                 FILE_BOTH_DIRECTORY_INFO * pFindData = 
852                         (FILE_BOTH_DIRECTORY_INFO *)current_entry;
853                 filename = &pFindData->FileName[0];
854                 len = le32_to_cpu(pFindData->FileNameLength);
855                 cifsFile->srch_inf.resume_key = pFindData->FileIndex;
856         } else {
857                 cFYI(1,("Unknown findfirst level %d",level));
858                 return -EINVAL;
859         }
860         cifsFile->srch_inf.resume_name_len = len;
861         cifsFile->srch_inf.presume_name = filename;
862         return rc;
863 }
864
865 int cifs_readdir(struct file *file, void *direntry, filldir_t filldir)
866 {
867         int rc = 0;
868         int xid,i;
869         struct cifs_sb_info *cifs_sb;
870         struct cifsTconInfo *pTcon;
871         struct cifsFileInfo *cifsFile = NULL;
872         char * current_entry;
873         int num_to_fill = 0;
874         char * tmp_buf = NULL;
875         char * end_of_smb;
876
877         xid = GetXid();
878
879         if(file->f_dentry == NULL) {
880                 FreeXid(xid);
881                 return -EIO;
882         }
883
884         cifs_sb = CIFS_SB(file->f_dentry->d_sb);
885         pTcon = cifs_sb->tcon;
886         if(pTcon == NULL)
887                 return -EINVAL;
888
889         switch ((int) file->f_pos) {
890         case 0:
891                 /*if (filldir(direntry, ".", 1, file->f_pos,
892                      file->f_dentry->d_inode->i_ino, DT_DIR) < 0) {
893                         cERROR(1, ("Filldir for current dir failed "));
894                         rc = -ENOMEM;
895                         break;
896                 }
897                 file->f_pos++; */
898         case 1:
899                 /* if (filldir(direntry, "..", 2, file->f_pos,
900                      file->f_dentry->d_parent->d_inode->i_ino, DT_DIR) < 0) {
901                         cERROR(1, ("Filldir for parent dir failed "));
902                         rc = -ENOMEM;
903                         break;
904                 }
905                 file->f_pos++; */
906         case 2:
907                 /* 1) If search is active, 
908                         is in current search buffer? 
909                         if it before then restart search
910                         if after then keep searching till find it */
911
912                 if(file->private_data == NULL) {
913                         rc = initiate_cifs_search(xid,file);
914                         cFYI(1,("initiate cifs search rc %d",rc));
915                         if(rc) {
916                                 FreeXid(xid);
917                                 return rc;
918                         }
919                 }
920         default:
921                 if(file->private_data == NULL) {
922                         rc = -EINVAL;
923                         FreeXid(xid);
924                         return rc;
925                 }
926                 cifsFile = file->private_data;
927                 if (cifsFile->srch_inf.endOfSearch) {
928                         if(cifsFile->srch_inf.emptyDir) {
929                                 cFYI(1, ("End of search, empty dir"));
930                                 rc = 0;
931                                 break;
932                         }
933                 } /* else {
934                         cifsFile->invalidHandle = TRUE;
935                         CIFSFindClose(xid, pTcon, cifsFile->netfid);
936                 } 
937                 kfree(cifsFile->search_resume_name);
938                 cifsFile->search_resume_name = NULL; */
939
940                 /* BB account for . and .. in f_pos as special case */
941
942                 rc = find_cifs_entry(xid,pTcon, file,
943                                 &current_entry,&num_to_fill);
944                 if(rc) {
945                         cFYI(1,("fce error %d",rc)); 
946                         goto rddir2_exit;
947                 } else if (current_entry != NULL) {
948                         cFYI(1,("entry %lld found",file->f_pos));
949                 } else {
950                         cFYI(1,("could not find entry"));
951                         goto rddir2_exit;
952                 }
953                 cFYI(1,("loop through %d times filling dir for net buf %p",
954                         num_to_fill,cifsFile->srch_inf.ntwrk_buf_start)); 
955                 end_of_smb = cifsFile->srch_inf.ntwrk_buf_start +
956                         smbCalcSize((struct smb_hdr *)
957                                     cifsFile->srch_inf.ntwrk_buf_start);
958                 /* To be safe - for UCS to UTF-8 with strings loaded
959                 with the rare long characters alloc more to account for
960                 such multibyte target UTF-8 characters. cifs_unicode.c,
961                 which actually does the conversion, has the same limit */
962                 tmp_buf = kmalloc((2 * NAME_MAX) + 4, GFP_KERNEL);
963                 for(i=0;(i<num_to_fill) && (rc == 0);i++) {
964                         if(current_entry == NULL) {
965                                 /* evaluate whether this case is an error */
966                                 cERROR(1,("past end of SMB num to fill %d i %d",
967                                           num_to_fill, i));
968                                 break;
969                         }
970
971                         rc = cifs_filldir(current_entry, file, 
972                                         filldir, direntry,tmp_buf);
973                         file->f_pos++;
974                         if(file->f_pos == cifsFile->srch_inf.index_of_last_entry) {
975                                 cFYI(1,("last entry in buf at pos %lld %s",
976                                         file->f_pos,tmp_buf)); /* BB removeme BB */
977                                 cifs_save_resume_key(current_entry,cifsFile);
978                                 break;
979                         } else 
980                                 current_entry = nxt_dir_entry(current_entry,
981                                                               end_of_smb);
982                 }
983                 kfree(tmp_buf);
984                 break;
985         } /* end switch */
986
987 rddir2_exit:
988         FreeXid(xid);
989         return rc;
990 }