[CIFS] Fix oops in cifs_create when nfsd server exports cifs mount
[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                         mode &= ~current->fs->umask;
213                         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
214                                 CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
215                                         (__u64)current->fsuid,
216                                         (__u64)current->fsgid,
217                                         0 /* dev */,
218                                         cifs_sb->local_nls,
219                                         cifs_sb->mnt_cifs_flags &
220                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
221                         } else {
222                                 CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
223                                         (__u64)-1,
224                                         (__u64)-1,
225                                         0 /* dev */,
226                                         cifs_sb->local_nls,
227                                         cifs_sb->mnt_cifs_flags &
228                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
229                         }
230                 } else {
231                         /* BB implement mode setting via Windows security
232                            descriptors e.g. */
233                         /* CIFSSMBWinSetPerms(xid,pTcon,path,mode,-1,-1,nls);*/
234
235                         /* Could set r/o dos attribute if mode & 0222 == 0 */
236                 }
237
238         /* BB server might mask mode so we have to query for Unix case*/
239                 if (pTcon->ses->capabilities & CAP_UNIX)
240                         rc = cifs_get_inode_info_unix(&newinode, full_path,
241                                                  inode->i_sb, xid);
242                 else {
243                         rc = cifs_get_inode_info(&newinode, full_path,
244                                                  buf, inode->i_sb, xid);
245                         if (newinode) {
246                                 newinode->i_mode = mode;
247                                 if ((oplock & CIFS_CREATE_ACTION) &&
248                                     (cifs_sb->mnt_cifs_flags &
249                                      CIFS_MOUNT_SET_UID)) {
250                                         newinode->i_uid = current->fsuid;
251                                         newinode->i_gid = current->fsgid;
252                                 }
253                         }
254                 }
255
256                 if (rc != 0) {
257                         cFYI(1,
258                              ("Create worked but get_inode_info failed rc = %d",
259                               rc));
260                 } else {
261                         if (pTcon->nocase)
262                                 direntry->d_op = &cifs_ci_dentry_ops;
263                         else
264                                 direntry->d_op = &cifs_dentry_ops;
265                         d_instantiate(direntry, newinode);
266                 }
267                 if ((nd == NULL /* nfsd case - nfs srv does not set nd */) ||
268                         ((nd->flags & LOOKUP_OPEN) == FALSE)) {
269                         /* mknod case - do not leave file open */
270                         CIFSSMBClose(xid, pTcon, fileHandle);
271                 } else if (newinode) {
272                         pCifsFile =
273                            kzalloc(sizeof (struct cifsFileInfo), GFP_KERNEL);
274
275                         if (pCifsFile == NULL)
276                                 goto cifs_create_out;
277                         pCifsFile->netfid = fileHandle;
278                         pCifsFile->pid = current->tgid;
279                         pCifsFile->pInode = newinode;
280                         pCifsFile->invalidHandle = FALSE;
281                         pCifsFile->closePend     = FALSE;
282                         init_MUTEX(&pCifsFile->fh_sem);
283                         mutex_init(&pCifsFile->lock_mutex);
284                         INIT_LIST_HEAD(&pCifsFile->llist);
285                         atomic_set(&pCifsFile->wrtPending, 0);
286
287                         /* set the following in open now
288                                 pCifsFile->pfile = file; */
289                         write_lock(&GlobalSMBSeslock);
290                         list_add(&pCifsFile->tlist, &pTcon->openFileList);
291                         pCifsInode = CIFS_I(newinode);
292                         if (pCifsInode) {
293                                 /* if readable file instance put first in list*/
294                                 if (write_only == TRUE) {
295                                         list_add_tail(&pCifsFile->flist,
296                                                 &pCifsInode->openFileList);
297                                 } else {
298                                         list_add(&pCifsFile->flist,
299                                                 &pCifsInode->openFileList);
300                                 }
301                                 if ((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
302                                         pCifsInode->clientCanCacheAll = TRUE;
303                                         pCifsInode->clientCanCacheRead = TRUE;
304                                         cFYI(1, ("Exclusive Oplock inode %p",
305                                                 newinode));
306                                 } else if ((oplock & 0xF) == OPLOCK_READ)
307                                         pCifsInode->clientCanCacheRead = TRUE;
308                         }
309                         write_unlock(&GlobalSMBSeslock);
310                 }
311         }
312 cifs_create_out:
313         kfree(buf);
314         kfree(full_path);
315         FreeXid(xid);
316         return rc;
317 }
318
319 int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode,
320                 dev_t device_number)
321 {
322         int rc = -EPERM;
323         int xid;
324         struct cifs_sb_info *cifs_sb;
325         struct cifsTconInfo *pTcon;
326         char *full_path = NULL;
327         struct inode *newinode = NULL;
328
329         if (!old_valid_dev(device_number))
330                 return -EINVAL;
331
332         xid = GetXid();
333
334         cifs_sb = CIFS_SB(inode->i_sb);
335         pTcon = cifs_sb->tcon;
336
337         full_path = build_path_from_dentry(direntry);
338         if (full_path == NULL)
339                 rc = -ENOMEM;
340         else if (pTcon->ses->capabilities & CAP_UNIX) {
341                 mode &= ~current->fs->umask;
342                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
343                         rc = CIFSSMBUnixSetPerms(xid, pTcon, full_path,
344                                 mode, (__u64)current->fsuid,
345                                 (__u64)current->fsgid,
346                                 device_number, cifs_sb->local_nls,
347                                 cifs_sb->mnt_cifs_flags &
348                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
349                 } else {
350                         rc = CIFSSMBUnixSetPerms(xid, pTcon,
351                                 full_path, mode, (__u64)-1, (__u64)-1,
352                                 device_number, cifs_sb->local_nls,
353                                 cifs_sb->mnt_cifs_flags &
354                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
355                 }
356
357                 if (!rc) {
358                         rc = cifs_get_inode_info_unix(&newinode, full_path,
359                                                 inode->i_sb, xid);
360                         if (pTcon->nocase)
361                                 direntry->d_op = &cifs_ci_dentry_ops;
362                         else
363                                 direntry->d_op = &cifs_dentry_ops;
364                         if (rc == 0)
365                                 d_instantiate(direntry, newinode);
366                 }
367         } else {
368                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) {
369                         int oplock = 0;
370                         u16 fileHandle;
371                         FILE_ALL_INFO * buf;
372
373                         cFYI(1, ("sfu compat create special file"));
374
375                         buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
376                         if (buf == NULL) {
377                                 kfree(full_path);
378                                 FreeXid(xid);
379                                 return -ENOMEM;
380                         }
381
382                         rc = CIFSSMBOpen(xid, pTcon, full_path,
383                                          FILE_CREATE, /* fail if exists */
384                                          GENERIC_WRITE /* BB would
385                                           WRITE_OWNER | WRITE_DAC be better? */,
386                                          /* Create a file and set the
387                                             file attribute to SYSTEM */
388                                          CREATE_NOT_DIR | CREATE_OPTION_SPECIAL,
389                                          &fileHandle, &oplock, buf,
390                                          cifs_sb->local_nls,
391                                          cifs_sb->mnt_cifs_flags &
392                                             CIFS_MOUNT_MAP_SPECIAL_CHR);
393
394                         /* BB FIXME - add handling for backlevel servers
395                            which need legacy open and check for all
396                            calls to SMBOpen for fallback to SMBLeagcyOpen */
397                         if (!rc) {
398                                 /* BB Do not bother to decode buf since no
399                                    local inode yet to put timestamps in,
400                                    but we can reuse it safely */
401                                 int bytes_written;
402                                 struct win_dev *pdev;
403                                 pdev = (struct win_dev *)buf;
404                                 if (S_ISCHR(mode)) {
405                                         memcpy(pdev->type, "IntxCHR", 8);
406                                         pdev->major =
407                                               cpu_to_le64(MAJOR(device_number));
408                                         pdev->minor =
409                                               cpu_to_le64(MINOR(device_number));
410                                         rc = CIFSSMBWrite(xid, pTcon,
411                                                 fileHandle,
412                                                 sizeof(struct win_dev),
413                                                 0, &bytes_written, (char *)pdev,
414                                                 NULL, 0);
415                                 } else if (S_ISBLK(mode)) {
416                                         memcpy(pdev->type, "IntxBLK", 8);
417                                         pdev->major =
418                                               cpu_to_le64(MAJOR(device_number));
419                                         pdev->minor =
420                                               cpu_to_le64(MINOR(device_number));
421                                         rc = CIFSSMBWrite(xid, pTcon,
422                                                 fileHandle,
423                                                 sizeof(struct win_dev),
424                                                 0, &bytes_written, (char *)pdev,
425                                                 NULL, 0);
426                                 } /* else if(S_ISFIFO */
427                                 CIFSSMBClose(xid, pTcon, fileHandle);
428                                 d_drop(direntry);
429                         }
430                         kfree(buf);
431                         /* add code here to set EAs */
432                 }
433         }
434
435         kfree(full_path);
436         FreeXid(xid);
437         return rc;
438 }
439
440
441 struct dentry *
442 cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
443             struct nameidata *nd)
444 {
445         int xid;
446         int rc = 0; /* to get around spurious gcc warning, set to zero here */
447         struct cifs_sb_info *cifs_sb;
448         struct cifsTconInfo *pTcon;
449         struct inode *newInode = NULL;
450         char *full_path = NULL;
451
452         xid = GetXid();
453
454         cFYI(1,
455              (" parent inode = 0x%p name is: %s and dentry = 0x%p",
456               parent_dir_inode, direntry->d_name.name, direntry));
457
458         /* check whether path exists */
459
460         cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
461         pTcon = cifs_sb->tcon;
462
463         /*
464          * Don't allow the separator character in a path component.
465          * The VFS will not allow "/", but "\" is allowed by posix.
466          */
467         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)) {
468                 int i;
469                 for (i = 0; i < direntry->d_name.len; i++)
470                         if (direntry->d_name.name[i] == '\\') {
471                                 cFYI(1, ("Invalid file name"));
472                                 FreeXid(xid);
473                                 return ERR_PTR(-EINVAL);
474                         }
475         }
476
477         /* can not grab the rename sem here since it would
478         deadlock in the cases (beginning of sys_rename itself)
479         in which we already have the sb rename sem */
480         full_path = build_path_from_dentry(direntry);
481         if (full_path == NULL) {
482                 FreeXid(xid);
483                 return ERR_PTR(-ENOMEM);
484         }
485
486         if (direntry->d_inode != NULL) {
487                 cFYI(1, (" non-NULL inode in lookup"));
488         } else {
489                 cFYI(1, (" NULL inode in lookup"));
490         }
491         cFYI(1,
492              (" Full path: %s inode = 0x%p", full_path, direntry->d_inode));
493
494         if (pTcon->ses->capabilities & CAP_UNIX)
495                 rc = cifs_get_inode_info_unix(&newInode, full_path,
496                                               parent_dir_inode->i_sb, xid);
497         else
498                 rc = cifs_get_inode_info(&newInode, full_path, NULL,
499                                          parent_dir_inode->i_sb, xid);
500
501         if ((rc == 0) && (newInode != NULL)) {
502                 if (pTcon->nocase)
503                         direntry->d_op = &cifs_ci_dentry_ops;
504                 else
505                         direntry->d_op = &cifs_dentry_ops;
506                 d_add(direntry, newInode);
507
508                 /* since paths are not looked up by component - the parent
509                    directories are presumed to be good here */
510                 renew_parental_timestamps(direntry);
511
512         } else if (rc == -ENOENT) {
513                 rc = 0;
514                 direntry->d_time = jiffies;
515                 if (pTcon->nocase)
516                         direntry->d_op = &cifs_ci_dentry_ops;
517                 else
518                         direntry->d_op = &cifs_dentry_ops;
519                 d_add(direntry, NULL);
520         /*      if it was once a directory (but how can we tell?) we could do
521                 shrink_dcache_parent(direntry); */
522         } else {
523                 cERROR(1, ("Error 0x%x on cifs_get_inode_info in lookup of %s",
524                            rc, full_path));
525                 /* BB special case check for Access Denied - watch security
526                 exposure of returning dir info implicitly via different rc
527                 if file exists or not but no access BB */
528         }
529
530         kfree(full_path);
531         FreeXid(xid);
532         return ERR_PTR(rc);
533 }
534
535 static int
536 cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd)
537 {
538         int isValid = 1;
539
540         if (direntry->d_inode) {
541                 if (cifs_revalidate(direntry)) {
542                         return 0;
543                 }
544         } else {
545                 cFYI(1, ("neg dentry 0x%p name = %s",
546                          direntry, direntry->d_name.name));
547                 if (time_after(jiffies, direntry->d_time + HZ) ||
548                         !lookupCacheEnabled) {
549                         d_drop(direntry);
550                         isValid = 0;
551                 }
552         }
553
554         return isValid;
555 }
556
557 /* static int cifs_d_delete(struct dentry *direntry)
558 {
559         int rc = 0;
560
561         cFYI(1, ("In cifs d_delete, name = %s", direntry->d_name.name));
562
563         return rc;
564 }     */
565
566 struct dentry_operations cifs_dentry_ops = {
567         .d_revalidate = cifs_d_revalidate,
568 /* d_delete:       cifs_d_delete,      */ /* not needed except for debugging */
569 };
570
571 static int cifs_ci_hash(struct dentry *dentry, struct qstr *q)
572 {
573         struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;
574         unsigned long hash;
575         int i;
576
577         hash = init_name_hash();
578         for (i = 0; i < q->len; i++)
579                 hash = partial_name_hash(nls_tolower(codepage, q->name[i]),
580                                          hash);
581         q->hash = end_name_hash(hash);
582
583         return 0;
584 }
585
586 static int cifs_ci_compare(struct dentry *dentry, struct qstr *a,
587                            struct qstr *b)
588 {
589         struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;
590
591         if ((a->len == b->len) &&
592             (nls_strnicmp(codepage, a->name, b->name, a->len) == 0)) {
593                 /*
594                  * To preserve case, don't let an existing negative dentry's
595                  * case take precedence.  If a is not a negative dentry, this
596                  * should have no side effects
597                  */
598                 memcpy((unsigned char *)a->name, b->name, a->len);
599                 return 0;
600         }
601         return 1;
602 }
603
604 struct dentry_operations cifs_ci_dentry_ops = {
605         .d_revalidate = cifs_d_revalidate,
606         .d_hash = cifs_ci_hash,
607         .d_compare = cifs_ci_compare,
608 };