f085db965788dbee306c1dc635c21002ac49bfad
[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., 2002,2005
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/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         char *full_path;
53         char dirsep;
54
55         if (direntry == NULL)
56                 return NULL;  /* not much we can do if dentry is freed and
57                 we need to reopen the file after it was closed implicitly
58                 when the server crashed */
59
60         dirsep = CIFS_DIR_SEP(CIFS_SB(direntry->d_sb));
61         pplen = CIFS_SB(direntry->d_sb)->prepathlen;
62 cifs_bp_rename_retry:
63         namelen = pplen;
64         for (temp = direntry; !IS_ROOT(temp);) {
65                 namelen += (1 + temp->d_name.len);
66                 temp = temp->d_parent;
67                 if (temp == NULL) {
68                         cERROR(1, ("corrupt dentry"));
69                         return NULL;
70                 }
71         }
72
73         full_path = kmalloc(namelen+1, GFP_KERNEL);
74         if (full_path == NULL)
75                 return full_path;
76         full_path[namelen] = 0; /* trailing null */
77         for (temp = direntry; !IS_ROOT(temp);) {
78                 namelen -= 1 + temp->d_name.len;
79                 if (namelen < 0) {
80                         break;
81                 } else {
82                         full_path[namelen] = dirsep;
83                         strncpy(full_path + namelen + 1, temp->d_name.name,
84                                 temp->d_name.len);
85                         cFYI(0, ("name: %s", full_path + namelen));
86                 }
87                 temp = temp->d_parent;
88                 if (temp == NULL) {
89                         cERROR(1, ("corrupt dentry"));
90                         kfree(full_path);
91                         return NULL;
92                 }
93         }
94         if (namelen != pplen) {
95                 cERROR(1,
96                        ("did not end path lookup where expected namelen is %d",
97                         namelen));
98                 /* presumably this is only possible if racing with a rename
99                 of one of the parent directories  (we can not lock the dentries
100                 above us to prevent this, but retrying should be harmless) */
101                 kfree(full_path);
102                 goto cifs_bp_rename_retry;
103         }
104         /* DIR_SEP already set for byte  0 / vs \ but not for
105            subsequent slashes in prepath which currently must
106            be entered the right way - not sure if there is an alternative
107            since the '\' is a valid posix character so we can not switch
108            those safely to '/' if any are found in the middle of the prepath */
109         /* BB test paths to Windows with '/' in the midst of prepath */
110         strncpy(full_path, CIFS_SB(direntry->d_sb)->prepath, pplen);
111         return full_path;
112 }
113
114 /* char * build_wildcard_path_from_dentry(struct dentry *direntry)
115 {
116         if(full_path == NULL)
117                 return full_path;
118
119         full_path[namelen] = '\\';
120         full_path[namelen+1] = '*';
121         full_path[namelen+2] = 0;
122 BB remove above eight lines BB */
123
124 /* Inode operations in similar order to how they appear in Linux file fs.h */
125
126 int
127 cifs_create(struct inode *inode, struct dentry *direntry, int mode,
128                 struct nameidata *nd)
129 {
130         int rc = -ENOENT;
131         int xid;
132         int oplock = 0;
133         int desiredAccess = GENERIC_READ | GENERIC_WRITE;
134         __u16 fileHandle;
135         struct cifs_sb_info *cifs_sb;
136         struct cifsTconInfo *pTcon;
137         char *full_path = NULL;
138         FILE_ALL_INFO * buf = NULL;
139         struct inode *newinode = NULL;
140         struct cifsFileInfo * pCifsFile = NULL;
141         struct cifsInodeInfo * pCifsInode;
142         int disposition = FILE_OVERWRITE_IF;
143         int write_only = FALSE;
144
145         xid = GetXid();
146
147         cifs_sb = CIFS_SB(inode->i_sb);
148         pTcon = cifs_sb->tcon;
149
150         full_path = build_path_from_dentry(direntry);
151         if (full_path == NULL) {
152                 FreeXid(xid);
153                 return -ENOMEM;
154         }
155
156         if (nd && (nd->flags & LOOKUP_OPEN)) {
157                 int oflags = nd->intent.open.flags;
158
159                 desiredAccess = 0;
160                 if (oflags & FMODE_READ)
161                         desiredAccess |= GENERIC_READ;
162                 if (oflags & FMODE_WRITE) {
163                         desiredAccess |= GENERIC_WRITE;
164                         if (!(oflags & FMODE_READ))
165                                 write_only = TRUE;
166                 }
167
168                 if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
169                         disposition = FILE_CREATE;
170                 else if ((oflags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
171                         disposition = FILE_OVERWRITE_IF;
172                 else if ((oflags & O_CREAT) == O_CREAT)
173                         disposition = FILE_OPEN_IF;
174                 else {
175                         cFYI(1, ("Create flag not set in create function"));
176                 }
177         }
178
179         /* BB add processing to set equivalent of mode - e.g. via CreateX with
180            ACLs */
181         if (oplockEnabled)
182                 oplock = REQ_OPLOCK;
183
184         buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
185         if (buf == NULL) {
186                 kfree(full_path);
187                 FreeXid(xid);
188                 return -ENOMEM;
189         }
190         if (cifs_sb->tcon->ses->capabilities & CAP_NT_SMBS)
191                 rc = CIFSSMBOpen(xid, pTcon, full_path, disposition,
192                          desiredAccess, CREATE_NOT_DIR,
193                          &fileHandle, &oplock, buf, cifs_sb->local_nls,
194                          cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
195         else
196                 rc = -EIO; /* no NT SMB support fall into legacy open below */
197
198         if (rc == -EIO) {
199                 /* old server, retry the open legacy style */
200                 rc = SMBLegacyOpen(xid, pTcon, full_path, disposition,
201                         desiredAccess, CREATE_NOT_DIR,
202                         &fileHandle, &oplock, buf, cifs_sb->local_nls,
203                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
204         }
205         if (rc) {
206                 cFYI(1, ("cifs_create returned 0x%x", rc));
207         } else {
208                 /* If Open reported that we actually created a file
209                 then we now have to set the mode if possible */
210                 if ((cifs_sb->tcon->ses->capabilities & CAP_UNIX) &&
211                         (oplock & CIFS_CREATE_ACTION))
212                         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
213                                 CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
214                                         (__u64)current->fsuid,
215                                         (__u64)current->fsgid,
216                                         0 /* dev */,
217                                         cifs_sb->local_nls,
218                                         cifs_sb->mnt_cifs_flags &
219                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
220                         } else {
221                                 CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
222                                         (__u64)-1,
223                                         (__u64)-1,
224                                         0 /* dev */,
225                                         cifs_sb->local_nls,
226                                         cifs_sb->mnt_cifs_flags &
227                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
228                         }
229                 else {
230                         /* BB implement mode setting via Windows security
231                            descriptors e.g. */
232                         /* CIFSSMBWinSetPerms(xid,pTcon,path,mode,-1,-1,nls);*/
233
234                         /* Could set r/o dos attribute if mode & 0222 == 0 */
235                 }
236
237         /* BB server might mask mode so we have to query for Unix case*/
238                 if (pTcon->ses->capabilities & CAP_UNIX)
239                         rc = cifs_get_inode_info_unix(&newinode, full_path,
240                                                  inode->i_sb, xid);
241                 else {
242                         rc = cifs_get_inode_info(&newinode, full_path,
243                                                  buf, inode->i_sb, xid);
244                         if (newinode) {
245                                 newinode->i_mode = mode;
246                                 if ((oplock & CIFS_CREATE_ACTION) &&
247                                     (cifs_sb->mnt_cifs_flags &
248                                      CIFS_MOUNT_SET_UID)) {
249                                         newinode->i_uid = current->fsuid;
250                                         newinode->i_gid = current->fsgid;
251                                 }
252                         }
253                 }
254
255                 if (rc != 0) {
256                         cFYI(1,
257                              ("Create worked but get_inode_info failed rc = %d",
258                               rc));
259                 } else {
260                         if (pTcon->nocase)
261                                 direntry->d_op = &cifs_ci_dentry_ops;
262                         else
263                                 direntry->d_op = &cifs_dentry_ops;
264                         d_instantiate(direntry, newinode);
265                 }
266                 if ((nd->flags & LOOKUP_OPEN) == FALSE) {
267                         /* mknod case - do not leave file open */
268                         CIFSSMBClose(xid, pTcon, fileHandle);
269                 } else if (newinode) {
270                         pCifsFile =
271                            kzalloc(sizeof (struct cifsFileInfo), GFP_KERNEL);
272
273                         if (pCifsFile == NULL)
274                                 goto cifs_create_out;
275                         pCifsFile->netfid = fileHandle;
276                         pCifsFile->pid = current->tgid;
277                         pCifsFile->pInode = newinode;
278                         pCifsFile->invalidHandle = FALSE;
279                         pCifsFile->closePend     = FALSE;
280                         init_MUTEX(&pCifsFile->fh_sem);
281                         mutex_init(&pCifsFile->lock_mutex);
282                         INIT_LIST_HEAD(&pCifsFile->llist);
283                         atomic_set(&pCifsFile->wrtPending, 0);
284
285                         /* set the following in open now
286                                 pCifsFile->pfile = file; */
287                         write_lock(&GlobalSMBSeslock);
288                         list_add(&pCifsFile->tlist, &pTcon->openFileList);
289                         pCifsInode = CIFS_I(newinode);
290                         if (pCifsInode) {
291                                 /* if readable file instance put first in list*/
292                                 if (write_only == TRUE) {
293                                         list_add_tail(&pCifsFile->flist,
294                                                 &pCifsInode->openFileList);
295                                 } else {
296                                         list_add(&pCifsFile->flist,
297                                                 &pCifsInode->openFileList);
298                                 }
299                                 if ((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
300                                         pCifsInode->clientCanCacheAll = TRUE;
301                                         pCifsInode->clientCanCacheRead = TRUE;
302                                         cFYI(1, ("Exclusive Oplock inode %p",
303                                                 newinode));
304                                 } else if ((oplock & 0xF) == OPLOCK_READ)
305                                         pCifsInode->clientCanCacheRead = TRUE;
306                         }
307                         write_unlock(&GlobalSMBSeslock);
308                 }
309         }
310 cifs_create_out:
311         kfree(buf);
312         kfree(full_path);
313         FreeXid(xid);
314         return rc;
315 }
316
317 int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode,
318                 dev_t device_number)
319 {
320         int rc = -EPERM;
321         int xid;
322         struct cifs_sb_info *cifs_sb;
323         struct cifsTconInfo *pTcon;
324         char *full_path = NULL;
325         struct inode * newinode = NULL;
326
327         if (!old_valid_dev(device_number))
328                 return -EINVAL;
329
330         xid = GetXid();
331
332         cifs_sb = CIFS_SB(inode->i_sb);
333         pTcon = cifs_sb->tcon;
334
335         full_path = build_path_from_dentry(direntry);
336         if (full_path == NULL)
337                 rc = -ENOMEM;
338         else if (pTcon->ses->capabilities & CAP_UNIX) {
339                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
340                         rc = CIFSSMBUnixSetPerms(xid, pTcon, full_path,
341                                 mode, (__u64)current->fsuid,
342                                 (__u64)current->fsgid,
343                                 device_number, cifs_sb->local_nls,
344                                 cifs_sb->mnt_cifs_flags &
345                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
346                 } else {
347                         rc = CIFSSMBUnixSetPerms(xid, pTcon,
348                                 full_path, mode, (__u64)-1, (__u64)-1,
349                                 device_number, cifs_sb->local_nls,
350                                 cifs_sb->mnt_cifs_flags &
351                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
352                 }
353
354                 if (!rc) {
355                         rc = cifs_get_inode_info_unix(&newinode, full_path,
356                                                 inode->i_sb, xid);
357                         if (pTcon->nocase)
358                                 direntry->d_op = &cifs_ci_dentry_ops;
359                         else
360                                 direntry->d_op = &cifs_dentry_ops;
361                         if (rc == 0)
362                                 d_instantiate(direntry, newinode);
363                 }
364         } else {
365                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) {
366                         int oplock = 0;
367                         u16 fileHandle;
368                         FILE_ALL_INFO * buf;
369
370                         cFYI(1, ("sfu compat create special file"));
371
372                         buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
373                         if (buf == NULL) {
374                                 kfree(full_path);
375                                 FreeXid(xid);
376                                 return -ENOMEM;
377                         }
378
379                         rc = CIFSSMBOpen(xid, pTcon, full_path,
380                                          FILE_CREATE, /* fail if exists */
381                                          GENERIC_WRITE /* BB would
382                                           WRITE_OWNER | WRITE_DAC be better? */,
383                                          /* Create a file and set the
384                                             file attribute to SYSTEM */
385                                          CREATE_NOT_DIR | CREATE_OPTION_SPECIAL,
386                                          &fileHandle, &oplock, buf,
387                                          cifs_sb->local_nls,
388                                          cifs_sb->mnt_cifs_flags &
389                                             CIFS_MOUNT_MAP_SPECIAL_CHR);
390
391                         /* BB FIXME - add handling for backlevel servers
392                            which need legacy open and check for all
393                            calls to SMBOpen for fallback to SMBLeagcyOpen */
394                         if (!rc) {
395                                 /* BB Do not bother to decode buf since no
396                                    local inode yet to put timestamps in,
397                                    but we can reuse it safely */
398                                 int bytes_written;
399                                 struct win_dev *pdev;
400                                 pdev = (struct win_dev *)buf;
401                                 if (S_ISCHR(mode)) {
402                                         memcpy(pdev->type, "IntxCHR", 8);
403                                         pdev->major =
404                                               cpu_to_le64(MAJOR(device_number));
405                                         pdev->minor =
406                                               cpu_to_le64(MINOR(device_number));
407                                         rc = CIFSSMBWrite(xid, pTcon,
408                                                 fileHandle,
409                                                 sizeof(struct win_dev),
410                                                 0, &bytes_written, (char *)pdev,
411                                                 NULL, 0);
412                                 } else if (S_ISBLK(mode)) {
413                                         memcpy(pdev->type, "IntxBLK", 8);
414                                         pdev->major =
415                                               cpu_to_le64(MAJOR(device_number));
416                                         pdev->minor =
417                                               cpu_to_le64(MINOR(device_number));
418                                         rc = CIFSSMBWrite(xid, pTcon,
419                                                 fileHandle,
420                                                 sizeof(struct win_dev),
421                                                 0, &bytes_written, (char *)pdev,
422                                                 NULL, 0);
423                                 } /* else if(S_ISFIFO */
424                                 CIFSSMBClose(xid, pTcon, fileHandle);
425                                 d_drop(direntry);
426                         }
427                         kfree(buf);
428                         /* add code here to set EAs */
429                 }
430         }
431
432         kfree(full_path);
433         FreeXid(xid);
434         return rc;
435 }
436
437
438 struct dentry *
439 cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
440             struct nameidata *nd)
441 {
442         int xid;
443         int rc = 0; /* to get around spurious gcc warning, set to zero here */
444         struct cifs_sb_info *cifs_sb;
445         struct cifsTconInfo *pTcon;
446         struct inode *newInode = NULL;
447         char *full_path = NULL;
448
449         xid = GetXid();
450
451         cFYI(1,
452              (" parent inode = 0x%p name is: %s and dentry = 0x%p",
453               parent_dir_inode, direntry->d_name.name, direntry));
454
455         /* check whether path exists */
456
457         cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
458         pTcon = cifs_sb->tcon;
459
460         /*
461          * Don't allow the separator character in a path component.
462          * The VFS will not allow "/", but "\" is allowed by posix.
463          */
464         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)) {
465                 int i;
466                 for (i = 0; i < direntry->d_name.len; i++)
467                         if (direntry->d_name.name[i] == '\\') {
468                                 cFYI(1, ("Invalid file name"));
469                                 FreeXid(xid);
470                                 return ERR_PTR(-EINVAL);
471                         }
472         }
473
474         /* can not grab the rename sem here since it would
475         deadlock in the cases (beginning of sys_rename itself)
476         in which we already have the sb rename sem */
477         full_path = build_path_from_dentry(direntry);
478         if (full_path == NULL) {
479                 FreeXid(xid);
480                 return ERR_PTR(-ENOMEM);
481         }
482
483         if (direntry->d_inode != NULL) {
484                 cFYI(1, (" non-NULL inode in lookup"));
485         } else {
486                 cFYI(1, (" NULL inode in lookup"));
487         }
488         cFYI(1,
489              (" Full path: %s inode = 0x%p", full_path, direntry->d_inode));
490
491         if (pTcon->ses->capabilities & CAP_UNIX)
492                 rc = cifs_get_inode_info_unix(&newInode, full_path,
493                                               parent_dir_inode->i_sb, xid);
494         else
495                 rc = cifs_get_inode_info(&newInode, full_path, NULL,
496                                          parent_dir_inode->i_sb, xid);
497
498         if ((rc == 0) && (newInode != NULL)) {
499                 if (pTcon->nocase)
500                         direntry->d_op = &cifs_ci_dentry_ops;
501                 else
502                         direntry->d_op = &cifs_dentry_ops;
503                 d_add(direntry, newInode);
504
505                 /* since paths are not looked up by component - the parent
506                    directories are presumed to be good here */
507                 renew_parental_timestamps(direntry);
508
509         } else if (rc == -ENOENT) {
510                 rc = 0;
511                 direntry->d_time = jiffies;
512                 if (pTcon->nocase)
513                         direntry->d_op = &cifs_ci_dentry_ops;
514                 else
515                         direntry->d_op = &cifs_dentry_ops;
516                 d_add(direntry, NULL);
517         /*      if it was once a directory (but how can we tell?) we could do
518                 shrink_dcache_parent(direntry); */
519         } else {
520                 cERROR(1, ("Error 0x%x on cifs_get_inode_info in lookup of %s",
521                            rc, full_path));
522                 /* BB special case check for Access Denied - watch security
523                 exposure of returning dir info implicitly via different rc
524                 if file exists or not but no access BB */
525         }
526
527         kfree(full_path);
528         FreeXid(xid);
529         return ERR_PTR(rc);
530 }
531
532 static int
533 cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd)
534 {
535         int isValid = 1;
536
537         if (direntry->d_inode) {
538                 if (cifs_revalidate(direntry)) {
539                         return 0;
540                 }
541         } else {
542                 cFYI(1, ("neg dentry 0x%p name = %s",
543                          direntry, direntry->d_name.name));
544                 if (time_after(jiffies, direntry->d_time + HZ) ||
545                         !lookupCacheEnabled) {
546                         d_drop(direntry);
547                         isValid = 0;
548                 }
549         }
550
551         return isValid;
552 }
553
554 /* static int cifs_d_delete(struct dentry *direntry)
555 {
556         int rc = 0;
557
558         cFYI(1, ("In cifs d_delete, name = %s", direntry->d_name.name));
559
560         return rc;
561 }     */
562
563 struct dentry_operations cifs_dentry_ops = {
564         .d_revalidate = cifs_d_revalidate,
565 /* d_delete:       cifs_d_delete,      */ /* not needed except for debugging */
566 };
567
568 static int cifs_ci_hash(struct dentry *dentry, struct qstr *q)
569 {
570         struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;
571         unsigned long hash;
572         int i;
573
574         hash = init_name_hash();
575         for (i = 0; i < q->len; i++)
576                 hash = partial_name_hash(nls_tolower(codepage, q->name[i]),
577                                          hash);
578         q->hash = end_name_hash(hash);
579
580         return 0;
581 }
582
583 static int cifs_ci_compare(struct dentry *dentry, struct qstr *a,
584                            struct qstr *b)
585 {
586         struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;
587
588         if ((a->len == b->len) &&
589             (nls_strnicmp(codepage, a->name, b->name, a->len) == 0)) {
590                 /*
591                  * To preserve case, don't let an existing negative dentry's
592                  * case take precedence.  If a is not a negative dentry, this
593                  * should have no side effects
594                  */
595                 memcpy((unsigned char *)a->name, b->name, a->len);
596                 return 0;
597         }
598         return 1;
599 }
600
601 struct dentry_operations cifs_ci_dentry_ops = {
602         .d_revalidate = cifs_d_revalidate,
603         .d_hash = cifs_ci_hash,
604         .d_compare = cifs_ci_compare,
605 };