[PATCH] drivers/scsi/dpt_i2o.c: fix a NULL pointer dereference
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / cifs / dir.c
CommitLineData
1da177e4
LT
1/*
2 * fs/cifs/dir.c
3 *
4 * vfs operations that deal with dentries
5 *
6 * Copyright (C) International Business Machines Corp., 2002,2003
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
34void
35renew_parental_timestamps(struct dentry *direntry)
36{
37 /* BB check if there is a way to get the kernel to do this or if we really need this */
38 do {
39 direntry->d_time = jiffies;
40 direntry = direntry->d_parent;
41 } while (!IS_ROOT(direntry));
42}
43
44/* Note: caller must free return buffer */
45char *
46build_path_from_dentry(struct dentry *direntry)
47{
48 struct dentry *temp;
49 int namelen = 0;
50 char *full_path;
7f57356b 51 char dirsep = CIFS_DIR_SEP(CIFS_SB(direntry->d_sb));
1da177e4
LT
52
53 if(direntry == NULL)
54 return NULL; /* not much we can do if dentry is freed and
55 we need to reopen the file after it was closed implicitly
56 when the server crashed */
57
58cifs_bp_rename_retry:
59 for (temp = direntry; !IS_ROOT(temp);) {
60 namelen += (1 + temp->d_name.len);
61 temp = temp->d_parent;
62 if(temp == NULL) {
63 cERROR(1,("corrupt dentry"));
64 return NULL;
65 }
66 }
67
68 full_path = kmalloc(namelen+1, GFP_KERNEL);
69 if(full_path == NULL)
70 return full_path;
71 full_path[namelen] = 0; /* trailing null */
72
73 for (temp = direntry; !IS_ROOT(temp);) {
74 namelen -= 1 + temp->d_name.len;
75 if (namelen < 0) {
76 break;
77 } else {
7f57356b 78 full_path[namelen] = dirsep;
1da177e4
LT
79 strncpy(full_path + namelen + 1, temp->d_name.name,
80 temp->d_name.len);
81 cFYI(0, (" name: %s ", full_path + namelen));
82 }
83 temp = temp->d_parent;
84 if(temp == NULL) {
85 cERROR(1,("corrupt dentry"));
86 kfree(full_path);
87 return NULL;
88 }
89 }
90 if (namelen != 0) {
91 cERROR(1,
92 ("We did not end path lookup where we expected namelen is %d",
93 namelen));
94 /* presumably this is only possible if we were racing with a rename
95 of one of the parent directories (we can not lock the dentries
96 above us to prevent this, but retrying should be harmless) */
97 kfree(full_path);
98 namelen = 0;
99 goto cifs_bp_rename_retry;
100 }
101
102 return full_path;
103}
104
737b758c 105/* char * build_wildcard_path_from_dentry(struct dentry *direntry)
1da177e4 106{
1da177e4
LT
107 if(full_path == NULL)
108 return full_path;
109
110 full_path[namelen] = '\\';
111 full_path[namelen+1] = '*';
737b758c
SF
112 full_path[namelen+2] = 0;
113BB remove above eight lines BB */
1da177e4
LT
114
115/* Inode operations in similar order to how they appear in the Linux file fs.h */
116
117int
118cifs_create(struct inode *inode, struct dentry *direntry, int mode,
119 struct nameidata *nd)
120{
121 int rc = -ENOENT;
122 int xid;
123 int oplock = 0;
124 int desiredAccess = GENERIC_READ | GENERIC_WRITE;
125 __u16 fileHandle;
126 struct cifs_sb_info *cifs_sb;
127 struct cifsTconInfo *pTcon;
128 char *full_path = NULL;
129 FILE_ALL_INFO * buf = NULL;
130 struct inode *newinode = NULL;
131 struct cifsFileInfo * pCifsFile = NULL;
132 struct cifsInodeInfo * pCifsInode;
133 int disposition = FILE_OVERWRITE_IF;
134 int write_only = FALSE;
135
136 xid = GetXid();
137
138 cifs_sb = CIFS_SB(inode->i_sb);
139 pTcon = cifs_sb->tcon;
140
141 down(&direntry->d_sb->s_vfs_rename_sem);
142 full_path = build_path_from_dentry(direntry);
143 up(&direntry->d_sb->s_vfs_rename_sem);
144 if(full_path == NULL) {
145 FreeXid(xid);
146 return -ENOMEM;
147 }
148
e08fc045
MS
149 if(nd && (nd->flags & LOOKUP_OPEN)) {
150 int oflags = nd->intent.open.flags;
151
152 desiredAccess = 0;
153 if (oflags & FMODE_READ)
154 desiredAccess |= GENERIC_READ;
155 if (oflags & FMODE_WRITE) {
156 desiredAccess |= GENERIC_WRITE;
157 if (!(oflags & FMODE_READ))
158 write_only = TRUE;
1da177e4
LT
159 }
160
e08fc045 161 if((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
1da177e4 162 disposition = FILE_CREATE;
e08fc045 163 else if((oflags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
1da177e4 164 disposition = FILE_OVERWRITE_IF;
e08fc045 165 else if((oflags & O_CREAT) == O_CREAT)
1da177e4
LT
166 disposition = FILE_OPEN_IF;
167 else {
168 cFYI(1,("Create flag not set in create function"));
169 }
170 }
171
172 /* BB add processing to set equivalent of mode - e.g. via CreateX with ACLs */
173 if (oplockEnabled)
174 oplock = REQ_OPLOCK;
175
176 buf = kmalloc(sizeof(FILE_ALL_INFO),GFP_KERNEL);
177 if(buf == NULL) {
178 kfree(full_path);
179 FreeXid(xid);
180 return -ENOMEM;
181 }
182
183 rc = CIFSSMBOpen(xid, pTcon, full_path, disposition,
184 desiredAccess, CREATE_NOT_DIR,
737b758c
SF
185 &fileHandle, &oplock, buf, cifs_sb->local_nls,
186 cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
a9d02ad4
SF
187 if(rc == -EIO) {
188 /* old server, retry the open legacy style */
189 rc = SMBLegacyOpen(xid, pTcon, full_path, disposition,
190 desiredAccess, CREATE_NOT_DIR,
191 &fileHandle, &oplock, buf, cifs_sb->local_nls,
192 cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
193 }
1da177e4
LT
194 if (rc) {
195 cFYI(1, ("cifs_create returned 0x%x ", rc));
196 } else {
197 /* If Open reported that we actually created a file
198 then we now have to set the mode if possible */
199 if ((cifs_sb->tcon->ses->capabilities & CAP_UNIX) &&
200 (oplock & CIFS_CREATE_ACTION))
201 if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
202 CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
203 (__u64)current->euid,
204 (__u64)current->egid,
205 0 /* dev */,
737b758c
SF
206 cifs_sb->local_nls,
207 cifs_sb->mnt_cifs_flags &
208 CIFS_MOUNT_MAP_SPECIAL_CHR);
1da177e4
LT
209 } else {
210 CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
211 (__u64)-1,
212 (__u64)-1,
213 0 /* dev */,
737b758c
SF
214 cifs_sb->local_nls,
215 cifs_sb->mnt_cifs_flags &
216 CIFS_MOUNT_MAP_SPECIAL_CHR);
1da177e4
LT
217 }
218 else {
d7245c2c 219 /* BB implement mode setting via Windows security descriptors */
1da177e4
LT
220 /* eg CIFSSMBWinSetPerms(xid,pTcon,full_path,mode,-1,-1,local_nls);*/
221 /* could set r/o dos attribute if mode & 0222 == 0 */
222 }
223
224 /* BB server might mask mode so we have to query for Unix case*/
225 if (pTcon->ses->capabilities & CAP_UNIX)
226 rc = cifs_get_inode_info_unix(&newinode, full_path,
227 inode->i_sb,xid);
228 else {
229 rc = cifs_get_inode_info(&newinode, full_path,
230 buf, inode->i_sb,xid);
231 if(newinode)
232 newinode->i_mode = mode;
233 }
234
235 if (rc != 0) {
4a6d87f1
SF
236 cFYI(1,
237 ("Create worked but get_inode_info failed rc = %d",
1da177e4
LT
238 rc));
239 } else {
b92327fe
SF
240 if (pTcon->nocase)
241 direntry->d_op = &cifs_ci_dentry_ops;
242 else
243 direntry->d_op = &cifs_dentry_ops;
1da177e4
LT
244 d_instantiate(direntry, newinode);
245 }
246 if((nd->flags & LOOKUP_OPEN) == FALSE) {
247 /* mknod case - do not leave file open */
248 CIFSSMBClose(xid, pTcon, fileHandle);
249 } else if(newinode) {
d14537f1 250 pCifsFile =
1da177e4 251 kmalloc(sizeof (struct cifsFileInfo), GFP_KERNEL);
d14537f1
SF
252
253 if(pCifsFile == NULL)
254 goto cifs_create_out;
255 memset((char *)pCifsFile, 0,
256 sizeof (struct cifsFileInfo));
257 pCifsFile->netfid = fileHandle;
258 pCifsFile->pid = current->tgid;
259 pCifsFile->pInode = newinode;
260 pCifsFile->invalidHandle = FALSE;
261 pCifsFile->closePend = FALSE;
262 init_MUTEX(&pCifsFile->fh_sem);
263 /* set the following in open now
264 pCifsFile->pfile = file; */
265 write_lock(&GlobalSMBSeslock);
266 list_add(&pCifsFile->tlist,&pTcon->openFileList);
267 pCifsInode = CIFS_I(newinode);
268 if(pCifsInode) {
1da177e4 269 /* if readable file instance put first in list*/
d14537f1
SF
270 if (write_only == TRUE) {
271 list_add_tail(&pCifsFile->flist,
272 &pCifsInode->openFileList);
273 } else {
274 list_add(&pCifsFile->flist,
275 &pCifsInode->openFileList);
1da177e4 276 }
d14537f1
SF
277 if((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
278 pCifsInode->clientCanCacheAll = TRUE;
279 pCifsInode->clientCanCacheRead = TRUE;
280 cFYI(1,("Exclusive Oplock for inode %p",
281 newinode));
282 } else if((oplock & 0xF) == OPLOCK_READ)
283 pCifsInode->clientCanCacheRead = TRUE;
1da177e4 284 }
d14537f1 285 write_unlock(&GlobalSMBSeslock);
1da177e4
LT
286 }
287 }
d14537f1
SF
288cifs_create_out:
289 kfree(buf);
290 kfree(full_path);
1da177e4 291 FreeXid(xid);
1da177e4
LT
292 return rc;
293}
294
86c96b4b
SF
295int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode,
296 dev_t device_number)
1da177e4
LT
297{
298 int rc = -EPERM;
299 int xid;
300 struct cifs_sb_info *cifs_sb;
301 struct cifsTconInfo *pTcon;
302 char *full_path = NULL;
303 struct inode * newinode = NULL;
304
305 if (!old_valid_dev(device_number))
306 return -EINVAL;
307
308 xid = GetXid();
309
310 cifs_sb = CIFS_SB(inode->i_sb);
311 pTcon = cifs_sb->tcon;
312
313 down(&direntry->d_sb->s_vfs_rename_sem);
314 full_path = build_path_from_dentry(direntry);
315 up(&direntry->d_sb->s_vfs_rename_sem);
316 if(full_path == NULL)
317 rc = -ENOMEM;
4a6d87f1 318 else if (pTcon->ses->capabilities & CAP_UNIX) {
1da177e4
LT
319 if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
320 rc = CIFSSMBUnixSetPerms(xid, pTcon, full_path,
321 mode,(__u64)current->euid,(__u64)current->egid,
737b758c
SF
322 device_number, cifs_sb->local_nls,
323 cifs_sb->mnt_cifs_flags &
324 CIFS_MOUNT_MAP_SPECIAL_CHR);
1da177e4
LT
325 } else {
326 rc = CIFSSMBUnixSetPerms(xid, pTcon,
327 full_path, mode, (__u64)-1, (__u64)-1,
737b758c
SF
328 device_number, cifs_sb->local_nls,
329 cifs_sb->mnt_cifs_flags &
330 CIFS_MOUNT_MAP_SPECIAL_CHR);
1da177e4
LT
331 }
332
333 if(!rc) {
334 rc = cifs_get_inode_info_unix(&newinode, full_path,
335 inode->i_sb,xid);
b92327fe
SF
336 if (pTcon->nocase)
337 direntry->d_op = &cifs_ci_dentry_ops;
338 else
339 direntry->d_op = &cifs_dentry_ops;
1da177e4
LT
340 if(rc == 0)
341 d_instantiate(direntry, newinode);
342 }
d7245c2c 343 } else {
eda3c029
SF
344 if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) {
345 int oplock = 0;
346 u16 fileHandle;
347 FILE_ALL_INFO * buf;
d7245c2c
SF
348
349 cFYI(1,("sfu compat create special file"));
d7245c2c 350
eda3c029
SF
351 buf = kmalloc(sizeof(FILE_ALL_INFO),GFP_KERNEL);
352 if(buf == NULL) {
353 kfree(full_path);
354 FreeXid(xid);
355 return -ENOMEM;
356 }
357
358 rc = CIFSSMBOpen(xid, pTcon, full_path,
359 FILE_CREATE, /* fail if exists */
360 GENERIC_WRITE /* BB would
361 WRITE_OWNER | WRITE_DAC be better? */,
362 /* Create a file and set the
363 file attribute to SYSTEM */
364 CREATE_NOT_DIR | CREATE_OPTION_SPECIAL,
365 &fileHandle, &oplock, buf,
366 cifs_sb->local_nls,
367 cifs_sb->mnt_cifs_flags &
368 CIFS_MOUNT_MAP_SPECIAL_CHR);
369
370 if(!rc) {
371 /* BB Do not bother to decode buf since no
86c96b4b
SF
372 local inode yet to put timestamps in,
373 but we can reuse it safely */
374 int bytes_written;
375 struct win_dev *pdev;
376 pdev = (struct win_dev *)buf;
377 if(S_ISCHR(mode)) {
378 memcpy(pdev->type, "IntxCHR", 8);
379 pdev->major =
380 cpu_to_le64(MAJOR(device_number));
381 pdev->minor =
382 cpu_to_le64(MINOR(device_number));
383 rc = CIFSSMBWrite(xid, pTcon,
384 fileHandle,
385 sizeof(struct win_dev),
386 0, &bytes_written, (char *)pdev,
387 NULL, 0);
388 } else if(S_ISBLK(mode)) {
389 memcpy(pdev->type, "IntxBLK", 8);
390 pdev->major =
391 cpu_to_le64(MAJOR(device_number));
392 pdev->minor =
393 cpu_to_le64(MINOR(device_number));
394 rc = CIFSSMBWrite(xid, pTcon,
395 fileHandle,
396 sizeof(struct win_dev),
397 0, &bytes_written, (char *)pdev,
398 NULL, 0);
399 } /* else if(S_ISFIFO */
eda3c029
SF
400 CIFSSMBClose(xid, pTcon, fileHandle);
401 d_drop(direntry);
402 }
403 kfree(buf);
d7245c2c
SF
404 /* add code here to set EAs */
405 }
1da177e4
LT
406 }
407
d14537f1 408 kfree(full_path);
1da177e4 409 FreeXid(xid);
1da177e4
LT
410 return rc;
411}
412
413
414struct dentry *
415cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry, struct nameidata *nd)
416{
417 int xid;
418 int rc = 0; /* to get around spurious gcc warning, set to zero here */
419 struct cifs_sb_info *cifs_sb;
420 struct cifsTconInfo *pTcon;
421 struct inode *newInode = NULL;
422 char *full_path = NULL;
423
424 xid = GetXid();
425
426 cFYI(1,
427 (" parent inode = 0x%p name is: %s and dentry = 0x%p",
428 parent_dir_inode, direntry->d_name.name, direntry));
429
430 /* BB Add check of incoming data - e.g. frame not longer than maximum SMB - let server check the namelen BB */
431
432 /* check whether path exists */
433
434 cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
435 pTcon = cifs_sb->tcon;
436
437 /* can not grab the rename sem here since it would
438 deadlock in the cases (beginning of sys_rename itself)
439 in which we already have the sb rename sem */
440 full_path = build_path_from_dentry(direntry);
441 if(full_path == NULL) {
442 FreeXid(xid);
443 return ERR_PTR(-ENOMEM);
444 }
445
446 if (direntry->d_inode != NULL) {
447 cFYI(1, (" non-NULL inode in lookup"));
448 } else {
449 cFYI(1, (" NULL inode in lookup"));
450 }
451 cFYI(1,
452 (" Full path: %s inode = 0x%p", full_path, direntry->d_inode));
453
454 if (pTcon->ses->capabilities & CAP_UNIX)
455 rc = cifs_get_inode_info_unix(&newInode, full_path,
456 parent_dir_inode->i_sb,xid);
457 else
458 rc = cifs_get_inode_info(&newInode, full_path, NULL,
459 parent_dir_inode->i_sb,xid);
460
461 if ((rc == 0) && (newInode != NULL)) {
b92327fe
SF
462 if (pTcon->nocase)
463 direntry->d_op = &cifs_ci_dentry_ops;
464 else
465 direntry->d_op = &cifs_dentry_ops;
1da177e4
LT
466 d_add(direntry, newInode);
467
468 /* since paths are not looked up by component - the parent directories are presumed to be good here */
469 renew_parental_timestamps(direntry);
470
471 } else if (rc == -ENOENT) {
472 rc = 0;
473 d_add(direntry, NULL);
474 } else {
b2aeb9d5
SF
475 cERROR(1,("Error 0x%x on cifs_get_inode_info in lookup of %s",
476 rc,full_path));
1da177e4
LT
477 /* BB special case check for Access Denied - watch security
478 exposure of returning dir info implicitly via different rc
479 if file exists or not but no access BB */
480 }
481
d14537f1 482 kfree(full_path);
1da177e4
LT
483 FreeXid(xid);
484 return ERR_PTR(rc);
485}
486
1da177e4
LT
487static int
488cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd)
489{
490 int isValid = 1;
491
492/* lock_kernel(); *//* surely we do not want to lock the kernel for a whole network round trip which could take seconds */
493
494 if (direntry->d_inode) {
495 if (cifs_revalidate(direntry)) {
496 /* unlock_kernel(); */
497 return 0;
498 }
499 } else {
500 cFYI(1,
501 ("In cifs_d_revalidate with no inode but name = %s and dentry 0x%p",
502 direntry->d_name.name, direntry));
503 }
504
505/* unlock_kernel(); */
506
507 return isValid;
508}
509
510/* static int cifs_d_delete(struct dentry *direntry)
511{
512 int rc = 0;
513
514 cFYI(1, ("In cifs d_delete, name = %s", direntry->d_name.name));
515
516 return rc;
517} */
518
519struct dentry_operations cifs_dentry_ops = {
520 .d_revalidate = cifs_d_revalidate,
521/* d_delete: cifs_d_delete, *//* not needed except for debugging */
522 /* no need for d_hash, d_compare, d_release, d_iput ... yet. BB confirm this BB */
523};
b92327fe
SF
524
525static int cifs_ci_hash(struct dentry *dentry, struct qstr *q)
526{
527 struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;
528 unsigned long hash;
529 int i;
530
531 hash = init_name_hash();
532 for (i = 0; i < q->len; i++)
533 hash = partial_name_hash(nls_tolower(codepage, q->name[i]),
534 hash);
535 q->hash = end_name_hash(hash);
536
537 return 0;
538}
539
540static int cifs_ci_compare(struct dentry *dentry, struct qstr *a,
541 struct qstr *b)
542{
543 struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;
544
545 if ((a->len == b->len) &&
546 (nls_strnicmp(codepage, a->name, b->name, a->len) == 0)) {
547 /*
548 * To preserve case, don't let an existing negative dentry's
549 * case take precedence. If a is not a negative dentry, this
550 * should have no side effects
551 */
552 memcpy((unsigned char *)a->name, b->name, a->len);
553 return 0;
554 }
555 return 1;
556}
557
558struct dentry_operations cifs_ci_dentry_ops = {
559 .d_revalidate = cifs_d_revalidate,
560 .d_hash = cifs_ci_hash,
561 .d_compare = cifs_ci_compare,
562};