[CIFS] remove unused variables
[linux-2.6.git] / fs / cifs / dir.c
1 /*
2  *   fs/cifs/dir.c
3  *
4  *   vfs operations that deal with dentries
5  *
6  *   Copyright (C) International Business Machines  Corp., 2002,2008
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/slab.h>
26 #include <linux/namei.h>
27 #include "cifsfs.h"
28 #include "cifspdu.h"
29 #include "cifsglob.h"
30 #include "cifsproto.h"
31 #include "cifs_debug.h"
32 #include "cifs_fs_sb.h"
33
34 static void
35 renew_parental_timestamps(struct dentry *direntry)
36 {
37         /* BB check if there is a way to get the kernel to do this or if we
38            really need this */
39         do {
40                 direntry->d_time = jiffies;
41                 direntry = direntry->d_parent;
42         } while (!IS_ROOT(direntry));
43 }
44
45 /* Note: caller must free return buffer */
46 char *
47 build_path_from_dentry(struct dentry *direntry)
48 {
49         struct dentry *temp;
50         int namelen;
51         int pplen;
52         int dfsplen;
53         char *full_path;
54         char dirsep;
55         struct cifs_sb_info *cifs_sb;
56
57         if (direntry == NULL)
58                 return NULL;  /* not much we can do if dentry is freed and
59                 we need to reopen the file after it was closed implicitly
60                 when the server crashed */
61
62         cifs_sb = CIFS_SB(direntry->d_sb);
63         dirsep = CIFS_DIR_SEP(cifs_sb);
64         pplen = cifs_sb->prepathlen;
65         if (cifs_sb->tcon && (cifs_sb->tcon->Flags & SMB_SHARE_IS_IN_DFS))
66                 dfsplen = strnlen(cifs_sb->tcon->treeName, MAX_TREE_SIZE + 1);
67         else
68                 dfsplen = 0;
69 cifs_bp_rename_retry:
70         namelen = pplen + dfsplen;
71         for (temp = direntry; !IS_ROOT(temp);) {
72                 namelen += (1 + temp->d_name.len);
73                 temp = temp->d_parent;
74                 if (temp == NULL) {
75                         cERROR(1, ("corrupt dentry"));
76                         return NULL;
77                 }
78         }
79
80         full_path = kmalloc(namelen+1, GFP_KERNEL);
81         if (full_path == NULL)
82                 return full_path;
83         full_path[namelen] = 0; /* trailing null */
84         for (temp = direntry; !IS_ROOT(temp);) {
85                 namelen -= 1 + temp->d_name.len;
86                 if (namelen < 0) {
87                         break;
88                 } else {
89                         full_path[namelen] = dirsep;
90                         strncpy(full_path + namelen + 1, temp->d_name.name,
91                                 temp->d_name.len);
92                         cFYI(0, ("name: %s", full_path + namelen));
93                 }
94                 temp = temp->d_parent;
95                 if (temp == NULL) {
96                         cERROR(1, ("corrupt dentry"));
97                         kfree(full_path);
98                         return NULL;
99                 }
100         }
101         if (namelen != pplen + dfsplen) {
102                 cERROR(1,
103                        ("did not end path lookup where expected namelen is %d",
104                         namelen));
105                 /* presumably this is only possible if racing with a rename
106                 of one of the parent directories  (we can not lock the dentries
107                 above us to prevent this, but retrying should be harmless) */
108                 kfree(full_path);
109                 goto cifs_bp_rename_retry;
110         }
111         /* DIR_SEP already set for byte  0 / vs \ but not for
112            subsequent slashes in prepath which currently must
113            be entered the right way - not sure if there is an alternative
114            since the '\' is a valid posix character so we can not switch
115            those safely to '/' if any are found in the middle of the prepath */
116         /* BB test paths to Windows with '/' in the midst of prepath */
117
118         if (dfsplen) {
119                 strncpy(full_path, cifs_sb->tcon->treeName, dfsplen);
120                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) {
121                         int i;
122                         for (i = 0; i < dfsplen; i++) {
123                                 if (full_path[i] == '\\')
124                                         full_path[i] = '/';
125                         }
126                 }
127         }
128         strncpy(full_path + dfsplen, CIFS_SB(direntry->d_sb)->prepath, pplen);
129         return full_path;
130 }
131
132 /* Inode operations in similar order to how they appear in Linux file fs.h */
133
134 int
135 cifs_create(struct inode *inode, struct dentry *direntry, int mode,
136                 struct nameidata *nd)
137 {
138         int rc = -ENOENT;
139         int xid;
140         int create_options = CREATE_NOT_DIR;
141         int oplock = 0;
142         int desiredAccess = GENERIC_READ | GENERIC_WRITE;
143         __u16 fileHandle;
144         struct cifs_sb_info *cifs_sb;
145         struct cifsTconInfo *pTcon;
146         char *full_path = NULL;
147         FILE_ALL_INFO *buf = NULL;
148         struct inode *newinode = NULL;
149         struct cifsFileInfo *pCifsFile = NULL;
150         struct cifsInodeInfo *pCifsInode;
151         int disposition = FILE_OVERWRITE_IF;
152         bool write_only = false;
153
154         xid = GetXid();
155
156         cifs_sb = CIFS_SB(inode->i_sb);
157         pTcon = cifs_sb->tcon;
158
159         full_path = build_path_from_dentry(direntry);
160         if (full_path == NULL) {
161                 FreeXid(xid);
162                 return -ENOMEM;
163         }
164
165         if (nd && (nd->flags & LOOKUP_OPEN)) {
166                 int oflags = nd->intent.open.flags;
167
168                 desiredAccess = 0;
169                 if (oflags & FMODE_READ)
170                         desiredAccess |= GENERIC_READ;
171                 if (oflags & FMODE_WRITE) {
172                         desiredAccess |= GENERIC_WRITE;
173                         if (!(oflags & FMODE_READ))
174                                 write_only = true;
175                 }
176
177                 if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
178                         disposition = FILE_CREATE;
179                 else if ((oflags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
180                         disposition = FILE_OVERWRITE_IF;
181                 else if ((oflags & O_CREAT) == O_CREAT)
182                         disposition = FILE_OPEN_IF;
183                 else
184                         cFYI(1, ("Create flag not set in create function"));
185         }
186
187         /* BB add processing to set equivalent of mode - e.g. via CreateX with
188            ACLs */
189         if (oplockEnabled)
190                 oplock = REQ_OPLOCK;
191
192         buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
193         if (buf == NULL) {
194                 kfree(full_path);
195                 FreeXid(xid);
196                 return -ENOMEM;
197         }
198
199         mode &= ~current->fs->umask;
200
201         /*
202          * if we're not using unix extensions, see if we need to set
203          * ATTR_READONLY on the create call
204          */
205         if (!pTcon->unix_ext && (mode & S_IWUGO) == 0)
206                 create_options |= CREATE_OPTION_READONLY;
207
208         if (cifs_sb->tcon->ses->capabilities & CAP_NT_SMBS)
209                 rc = CIFSSMBOpen(xid, pTcon, full_path, disposition,
210                          desiredAccess, create_options,
211                          &fileHandle, &oplock, buf, cifs_sb->local_nls,
212                          cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
213         else
214                 rc = -EIO; /* no NT SMB support fall into legacy open below */
215
216         if (rc == -EIO) {
217                 /* old server, retry the open legacy style */
218                 rc = SMBLegacyOpen(xid, pTcon, full_path, disposition,
219                         desiredAccess, create_options,
220                         &fileHandle, &oplock, buf, cifs_sb->local_nls,
221                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
222         }
223         if (rc) {
224                 cFYI(1, ("cifs_create returned 0x%x", rc));
225         } else {
226                 /* If Open reported that we actually created a file
227                 then we now have to set the mode if possible */
228                 if ((pTcon->unix_ext) && (oplock & CIFS_CREATE_ACTION)) {
229                         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
230                                 CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
231                                         (__u64)current->fsuid,
232                                         (__u64)current->fsgid,
233                                         0 /* dev */,
234                                         cifs_sb->local_nls,
235                                         cifs_sb->mnt_cifs_flags &
236                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
237                         } else {
238                                 CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
239                                         (__u64)-1,
240                                         (__u64)-1,
241                                         0 /* dev */,
242                                         cifs_sb->local_nls,
243                                         cifs_sb->mnt_cifs_flags &
244                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
245                         }
246                 } else {
247                         /* BB implement mode setting via Windows security
248                            descriptors e.g. */
249                         /* CIFSSMBWinSetPerms(xid,pTcon,path,mode,-1,-1,nls);*/
250
251                         /* Could set r/o dos attribute if mode & 0222 == 0 */
252                 }
253
254                 /* server might mask mode so we have to query for it */
255                 if (pTcon->unix_ext)
256                         rc = cifs_get_inode_info_unix(&newinode, full_path,
257                                                  inode->i_sb, xid);
258                 else {
259                         rc = cifs_get_inode_info(&newinode, full_path,
260                                                  buf, inode->i_sb, xid,
261                                                  &fileHandle);
262                         if (newinode) {
263                                 newinode->i_mode = mode;
264                                 if ((oplock & CIFS_CREATE_ACTION) &&
265                                     (cifs_sb->mnt_cifs_flags &
266                                      CIFS_MOUNT_SET_UID)) {
267                                         newinode->i_uid = current->fsuid;
268                                         newinode->i_gid = current->fsgid;
269                                 }
270                         }
271                 }
272
273                 if (rc != 0) {
274                         cFYI(1,
275                              ("Create worked but get_inode_info failed rc = %d",
276                               rc));
277                 } else {
278                         if (pTcon->nocase)
279                                 direntry->d_op = &cifs_ci_dentry_ops;
280                         else
281                                 direntry->d_op = &cifs_dentry_ops;
282                         d_instantiate(direntry, newinode);
283                 }
284                 if ((nd == NULL /* nfsd case - nfs srv does not set nd */) ||
285                         (!(nd->flags & LOOKUP_OPEN))) {
286                         /* mknod case - do not leave file open */
287                         CIFSSMBClose(xid, pTcon, fileHandle);
288                 } else if (newinode) {
289                         pCifsFile =
290                            kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
291
292                         if (pCifsFile == NULL)
293                                 goto cifs_create_out;
294                         pCifsFile->netfid = fileHandle;
295                         pCifsFile->pid = current->tgid;
296                         pCifsFile->pInode = newinode;
297                         pCifsFile->invalidHandle = false;
298                         pCifsFile->closePend     = false;
299                         init_MUTEX(&pCifsFile->fh_sem);
300                         mutex_init(&pCifsFile->lock_mutex);
301                         INIT_LIST_HEAD(&pCifsFile->llist);
302                         atomic_set(&pCifsFile->wrtPending, 0);
303
304                         /* set the following in open now
305                                 pCifsFile->pfile = file; */
306                         write_lock(&GlobalSMBSeslock);
307                         list_add(&pCifsFile->tlist, &pTcon->openFileList);
308                         pCifsInode = CIFS_I(newinode);
309                         if (pCifsInode) {
310                                 /* if readable file instance put first in list*/
311                                 if (write_only) {
312                                         list_add_tail(&pCifsFile->flist,
313                                                 &pCifsInode->openFileList);
314                                 } else {
315                                         list_add(&pCifsFile->flist,
316                                                 &pCifsInode->openFileList);
317                                 }
318                                 if ((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
319                                         pCifsInode->clientCanCacheAll = true;
320                                         pCifsInode->clientCanCacheRead = true;
321                                         cFYI(1, ("Exclusive Oplock inode %p",
322                                                 newinode));
323                                 } else if ((oplock & 0xF) == OPLOCK_READ)
324                                         pCifsInode->clientCanCacheRead = true;
325                         }
326                         write_unlock(&GlobalSMBSeslock);
327                 }
328         }
329 cifs_create_out:
330         kfree(buf);
331         kfree(full_path);
332         FreeXid(xid);
333         return rc;
334 }
335
336 int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode,
337                 dev_t device_number)
338 {
339         int rc = -EPERM;
340         int xid;
341         struct cifs_sb_info *cifs_sb;
342         struct cifsTconInfo *pTcon;
343         char *full_path = NULL;
344         struct inode *newinode = NULL;
345
346         if (!old_valid_dev(device_number))
347                 return -EINVAL;
348
349         xid = GetXid();
350
351         cifs_sb = CIFS_SB(inode->i_sb);
352         pTcon = cifs_sb->tcon;
353
354         full_path = build_path_from_dentry(direntry);
355         if (full_path == NULL)
356                 rc = -ENOMEM;
357         else if (pTcon->unix_ext) {
358                 mode &= ~current->fs->umask;
359                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
360                         rc = CIFSSMBUnixSetPerms(xid, pTcon, full_path,
361                                 mode, (__u64)current->fsuid,
362                                 (__u64)current->fsgid,
363                                 device_number, cifs_sb->local_nls,
364                                 cifs_sb->mnt_cifs_flags &
365                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
366                 } else {
367                         rc = CIFSSMBUnixSetPerms(xid, pTcon,
368                                 full_path, mode, (__u64)-1, (__u64)-1,
369                                 device_number, cifs_sb->local_nls,
370                                 cifs_sb->mnt_cifs_flags &
371                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
372                 }
373
374                 if (!rc) {
375                         rc = cifs_get_inode_info_unix(&newinode, full_path,
376                                                 inode->i_sb, xid);
377                         if (pTcon->nocase)
378                                 direntry->d_op = &cifs_ci_dentry_ops;
379                         else
380                                 direntry->d_op = &cifs_dentry_ops;
381                         if (rc == 0)
382                                 d_instantiate(direntry, newinode);
383                 }
384         } else {
385                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) {
386                         int oplock = 0;
387                         u16 fileHandle;
388                         FILE_ALL_INFO *buf;
389
390                         cFYI(1, ("sfu compat create special file"));
391
392                         buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
393                         if (buf == NULL) {
394                                 kfree(full_path);
395                                 FreeXid(xid);
396                                 return -ENOMEM;
397                         }
398
399                         rc = CIFSSMBOpen(xid, pTcon, full_path,
400                                          FILE_CREATE, /* fail if exists */
401                                          GENERIC_WRITE /* BB would
402                                           WRITE_OWNER | WRITE_DAC be better? */,
403                                          /* Create a file and set the
404                                             file attribute to SYSTEM */
405                                          CREATE_NOT_DIR | CREATE_OPTION_SPECIAL,
406                                          &fileHandle, &oplock, buf,
407                                          cifs_sb->local_nls,
408                                          cifs_sb->mnt_cifs_flags &
409                                             CIFS_MOUNT_MAP_SPECIAL_CHR);
410
411                         /* BB FIXME - add handling for backlevel servers
412                            which need legacy open and check for all
413                            calls to SMBOpen for fallback to SMBLeagcyOpen */
414                         if (!rc) {
415                                 /* BB Do not bother to decode buf since no
416                                    local inode yet to put timestamps in,
417                                    but we can reuse it safely */
418                                 unsigned int bytes_written;
419                                 struct win_dev *pdev;
420                                 pdev = (struct win_dev *)buf;
421                                 if (S_ISCHR(mode)) {
422                                         memcpy(pdev->type, "IntxCHR", 8);
423                                         pdev->major =
424                                               cpu_to_le64(MAJOR(device_number));
425                                         pdev->minor =
426                                               cpu_to_le64(MINOR(device_number));
427                                         rc = CIFSSMBWrite(xid, pTcon,
428                                                 fileHandle,
429                                                 sizeof(struct win_dev),
430                                                 0, &bytes_written, (char *)pdev,
431                                                 NULL, 0);
432                                 } else if (S_ISBLK(mode)) {
433                                         memcpy(pdev->type, "IntxBLK", 8);
434                                         pdev->major =
435                                               cpu_to_le64(MAJOR(device_number));
436                                         pdev->minor =
437                                               cpu_to_le64(MINOR(device_number));
438                                         rc = CIFSSMBWrite(xid, pTcon,
439                                                 fileHandle,
440                                                 sizeof(struct win_dev),
441                                                 0, &bytes_written, (char *)pdev,
442                                                 NULL, 0);
443                                 } /* else if(S_ISFIFO */
444                                 CIFSSMBClose(xid, pTcon, fileHandle);
445                                 d_drop(direntry);
446                         }
447                         kfree(buf);
448                         /* add code here to set EAs */
449                 }
450         }
451
452         kfree(full_path);
453         FreeXid(xid);
454         return rc;
455 }
456
457
458 struct dentry *
459 cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
460             struct nameidata *nd)
461 {
462         int xid;
463         int rc = 0; /* to get around spurious gcc warning, set to zero here */
464         struct cifs_sb_info *cifs_sb;
465         struct cifsTconInfo *pTcon;
466         struct inode *newInode = NULL;
467         char *full_path = NULL;
468
469         xid = GetXid();
470
471         cFYI(1, (" parent inode = 0x%p name is: %s and dentry = 0x%p",
472               parent_dir_inode, direntry->d_name.name, direntry));
473
474         /* check whether path exists */
475
476         cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
477         pTcon = cifs_sb->tcon;
478
479         /*
480          * Don't allow the separator character in a path component.
481          * The VFS will not allow "/", but "\" is allowed by posix.
482          */
483         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)) {
484                 int i;
485                 for (i = 0; i < direntry->d_name.len; i++)
486                         if (direntry->d_name.name[i] == '\\') {
487                                 cFYI(1, ("Invalid file name"));
488                                 FreeXid(xid);
489                                 return ERR_PTR(-EINVAL);
490                         }
491         }
492
493         /* can not grab the rename sem here since it would
494         deadlock in the cases (beginning of sys_rename itself)
495         in which we already have the sb rename sem */
496         full_path = build_path_from_dentry(direntry);
497         if (full_path == NULL) {
498                 FreeXid(xid);
499                 return ERR_PTR(-ENOMEM);
500         }
501
502         if (direntry->d_inode != NULL) {
503                 cFYI(1, (" non-NULL inode in lookup"));
504         } else {
505                 cFYI(1, (" NULL inode in lookup"));
506         }
507         cFYI(1,
508              (" Full path: %s inode = 0x%p", full_path, direntry->d_inode));
509
510         if (pTcon->unix_ext)
511                 rc = cifs_get_inode_info_unix(&newInode, full_path,
512                                               parent_dir_inode->i_sb, xid);
513         else
514                 rc = cifs_get_inode_info(&newInode, full_path, NULL,
515                                          parent_dir_inode->i_sb, xid, NULL);
516
517         if ((rc == 0) && (newInode != NULL)) {
518                 if (pTcon->nocase)
519                         direntry->d_op = &cifs_ci_dentry_ops;
520                 else
521                         direntry->d_op = &cifs_dentry_ops;
522                 d_add(direntry, newInode);
523
524                 /* since paths are not looked up by component - the parent
525                    directories are presumed to be good here */
526                 renew_parental_timestamps(direntry);
527
528         } else if (rc == -ENOENT) {
529                 rc = 0;
530                 direntry->d_time = jiffies;
531                 if (pTcon->nocase)
532                         direntry->d_op = &cifs_ci_dentry_ops;
533                 else
534                         direntry->d_op = &cifs_dentry_ops;
535                 d_add(direntry, NULL);
536         /*      if it was once a directory (but how can we tell?) we could do
537                 shrink_dcache_parent(direntry); */
538         } else if (rc != -EACCES) {
539                 cERROR(1, ("Unexpected lookup error %d", rc));
540                 /* We special case check for Access Denied - since that
541                 is a common return code */
542         }
543
544         kfree(full_path);
545         FreeXid(xid);
546         return ERR_PTR(rc);
547 }
548
549 static int
550 cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd)
551 {
552         int isValid = 1;
553
554         if (direntry->d_inode) {
555                 if (cifs_revalidate(direntry))
556                         return 0;
557         } else {
558                 cFYI(1, ("neg dentry 0x%p name = %s",
559                          direntry, direntry->d_name.name));
560                 if (time_after(jiffies, direntry->d_time + HZ) ||
561                         !lookupCacheEnabled) {
562                         d_drop(direntry);
563                         isValid = 0;
564                 }
565         }
566
567         return isValid;
568 }
569
570 /* static int cifs_d_delete(struct dentry *direntry)
571 {
572         int rc = 0;
573
574         cFYI(1, ("In cifs d_delete, name = %s", direntry->d_name.name));
575
576         return rc;
577 }     */
578
579 struct dentry_operations cifs_dentry_ops = {
580         .d_revalidate = cifs_d_revalidate,
581 /* d_delete:       cifs_d_delete,      */ /* not needed except for debugging */
582 };
583
584 static int cifs_ci_hash(struct dentry *dentry, struct qstr *q)
585 {
586         struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;
587         unsigned long hash;
588         int i;
589
590         hash = init_name_hash();
591         for (i = 0; i < q->len; i++)
592                 hash = partial_name_hash(nls_tolower(codepage, q->name[i]),
593                                          hash);
594         q->hash = end_name_hash(hash);
595
596         return 0;
597 }
598
599 static int cifs_ci_compare(struct dentry *dentry, struct qstr *a,
600                            struct qstr *b)
601 {
602         struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;
603
604         if ((a->len == b->len) &&
605             (nls_strnicmp(codepage, a->name, b->name, a->len) == 0)) {
606                 /*
607                  * To preserve case, don't let an existing negative dentry's
608                  * case take precedence.  If a is not a negative dentry, this
609                  * should have no side effects
610                  */
611                 memcpy((void *)a->name, b->name, a->len);
612                 return 0;
613         }
614         return 1;
615 }
616
617 struct dentry_operations cifs_ci_dentry_ops = {
618         .d_revalidate = cifs_d_revalidate,
619         .d_hash = cifs_ci_hash,
620         .d_compare = cifs_ci_compare,
621 };