[PATCH] cifs_create() fix
[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., 2002,2003
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
34 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 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 */
45 char *
46 build_path_from_dentry(struct dentry *direntry)
47 {
48         struct dentry *temp;
49         int namelen = 0;
50         char *full_path;
51
52         if(direntry == NULL)
53                 return NULL;  /* not much we can do if dentry is freed and
54                 we need to reopen the file after it was closed implicitly
55                 when the server crashed */
56
57 cifs_bp_rename_retry:
58         for (temp = direntry; !IS_ROOT(temp);) {
59                 namelen += (1 + temp->d_name.len);
60                 temp = temp->d_parent;
61                 if(temp == NULL) {
62                         cERROR(1,("corrupt dentry"));
63                         return NULL;
64                 }
65         }
66
67         full_path = kmalloc(namelen+1, GFP_KERNEL);
68         if(full_path == NULL)
69                 return full_path;
70         full_path[namelen] = 0; /* trailing null */
71
72         for (temp = direntry; !IS_ROOT(temp);) {
73                 namelen -= 1 + temp->d_name.len;
74                 if (namelen < 0) {
75                         break;
76                 } else {
77                         full_path[namelen] = '\\';
78                         strncpy(full_path + namelen + 1, temp->d_name.name,
79                                 temp->d_name.len);
80                         cFYI(0, (" name: %s ", full_path + namelen));
81                 }
82                 temp = temp->d_parent;
83                 if(temp == NULL) {
84                         cERROR(1,("corrupt dentry"));
85                         kfree(full_path);
86                         return NULL;
87                 }
88         }
89         if (namelen != 0) {
90                 cERROR(1,
91                        ("We did not end path lookup where we expected namelen is %d",
92                         namelen));
93                 /* presumably this is only possible if we were racing with a rename 
94                 of one of the parent directories  (we can not lock the dentries
95                 above us to prevent this, but retrying should be harmless) */
96                 kfree(full_path);
97                 namelen = 0;
98                 goto cifs_bp_rename_retry;
99         }
100
101         return full_path;
102 }
103
104 /* char * build_wildcard_path_from_dentry(struct dentry *direntry)
105 {
106         if(full_path == NULL)
107                 return full_path;
108
109         full_path[namelen] = '\\';
110         full_path[namelen+1] = '*';
111         full_path[namelen+2] = 0;
112 BB remove above eight lines BB */
113
114 /* Inode operations in similar order to how they appear in the Linux file fs.h */
115
116 int
117 cifs_create(struct inode *inode, struct dentry *direntry, int mode,
118                 struct nameidata *nd)
119 {
120         int rc = -ENOENT;
121         int xid;
122         int oplock = 0;
123         int desiredAccess = GENERIC_READ | GENERIC_WRITE;
124         __u16 fileHandle;
125         struct cifs_sb_info *cifs_sb;
126         struct cifsTconInfo *pTcon;
127         char *full_path = NULL;
128         FILE_ALL_INFO * buf = NULL;
129         struct inode *newinode = NULL;
130         struct cifsFileInfo * pCifsFile = NULL;
131         struct cifsInodeInfo * pCifsInode;
132         int disposition = FILE_OVERWRITE_IF;
133         int write_only = FALSE;
134
135         xid = GetXid();
136
137         cifs_sb = CIFS_SB(inode->i_sb);
138         pTcon = cifs_sb->tcon;
139
140         down(&direntry->d_sb->s_vfs_rename_sem);
141         full_path = build_path_from_dentry(direntry);
142         up(&direntry->d_sb->s_vfs_rename_sem);
143         if(full_path == NULL) {
144                 FreeXid(xid);
145                 return -ENOMEM;
146         }
147
148         if(nd && (nd->flags & LOOKUP_OPEN)) {
149                 int oflags = nd->intent.open.flags;
150
151                 desiredAccess = 0;
152                 if (oflags & FMODE_READ)
153                         desiredAccess |= GENERIC_READ;
154                 if (oflags & FMODE_WRITE) {
155                         desiredAccess |= GENERIC_WRITE;
156                         if (!(oflags & FMODE_READ))
157                                 write_only = TRUE;
158                 }
159
160                 if((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
161                         disposition = FILE_CREATE;
162                 else if((oflags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
163                         disposition = FILE_OVERWRITE_IF;
164                 else if((oflags & O_CREAT) == O_CREAT)
165                         disposition = FILE_OPEN_IF;
166                 else {
167                         cFYI(1,("Create flag not set in create function"));
168                 }
169         }
170
171         /* BB add processing to set equivalent of mode - e.g. via CreateX with ACLs */
172         if (oplockEnabled)
173                 oplock = REQ_OPLOCK;
174
175         buf = kmalloc(sizeof(FILE_ALL_INFO),GFP_KERNEL);
176         if(buf == NULL) {
177                 kfree(full_path);
178                 FreeXid(xid);
179                 return -ENOMEM;
180         }
181
182         rc = CIFSSMBOpen(xid, pTcon, full_path, disposition,
183                          desiredAccess, CREATE_NOT_DIR,
184                          &fileHandle, &oplock, buf, cifs_sb->local_nls,
185                          cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
186         if (rc) {
187                 cFYI(1, ("cifs_create returned 0x%x ", rc));
188         } else {
189                 /* If Open reported that we actually created a file
190                 then we now have to set the mode if possible */
191                 if ((cifs_sb->tcon->ses->capabilities & CAP_UNIX) &&
192                         (oplock & CIFS_CREATE_ACTION))
193                         if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
194                                 CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
195                                         (__u64)current->euid,
196                                         (__u64)current->egid,
197                                         0 /* dev */,
198                                         cifs_sb->local_nls, 
199                                         cifs_sb->mnt_cifs_flags & 
200                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
201                         } else {
202                                 CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
203                                         (__u64)-1,
204                                         (__u64)-1,
205                                         0 /* dev */,
206                                         cifs_sb->local_nls,
207                                         cifs_sb->mnt_cifs_flags & 
208                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
209                         }
210                 else {
211                         /* BB implement via Windows security descriptors */
212                         /* eg CIFSSMBWinSetPerms(xid,pTcon,full_path,mode,-1,-1,local_nls);*/
213                         /* could set r/o dos attribute if mode & 0222 == 0 */
214                 }
215
216         /* BB server might mask mode so we have to query for Unix case*/
217                 if (pTcon->ses->capabilities & CAP_UNIX)
218                         rc = cifs_get_inode_info_unix(&newinode, full_path,
219                                                  inode->i_sb,xid);
220                 else {
221                         rc = cifs_get_inode_info(&newinode, full_path,
222                                                  buf, inode->i_sb,xid);
223                         if(newinode)
224                                 newinode->i_mode = mode;
225                 }
226
227                 if (rc != 0) {
228                         cFYI(1,("Create worked but get_inode_info failed with rc = %d",
229                               rc));
230                 } else {
231                         direntry->d_op = &cifs_dentry_ops;
232                         d_instantiate(direntry, newinode);
233                 }
234                 if((nd->flags & LOOKUP_OPEN) == FALSE) {
235                         /* mknod case - do not leave file open */
236                         CIFSSMBClose(xid, pTcon, fileHandle);
237                 } else if(newinode) {
238                         pCifsFile =
239                            kmalloc(sizeof (struct cifsFileInfo), GFP_KERNEL);
240                         
241                         if(pCifsFile == NULL)
242                                 goto cifs_create_out;
243                         memset((char *)pCifsFile, 0,
244                                sizeof (struct cifsFileInfo));
245                         pCifsFile->netfid = fileHandle;
246                         pCifsFile->pid = current->tgid;
247                         pCifsFile->pInode = newinode;
248                         pCifsFile->invalidHandle = FALSE;
249                         pCifsFile->closePend     = FALSE;
250                         init_MUTEX(&pCifsFile->fh_sem);
251                         /* set the following in open now 
252                                 pCifsFile->pfile = file; */
253                         write_lock(&GlobalSMBSeslock);
254                         list_add(&pCifsFile->tlist,&pTcon->openFileList);
255                         pCifsInode = CIFS_I(newinode);
256                         if(pCifsInode) {
257                                 /* if readable file instance put first in list*/
258                                 if (write_only == TRUE) {
259                                         list_add_tail(&pCifsFile->flist,
260                                                 &pCifsInode->openFileList);
261                                 } else {
262                                         list_add(&pCifsFile->flist,
263                                                 &pCifsInode->openFileList);
264                                 }
265                                 if((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
266                                         pCifsInode->clientCanCacheAll = TRUE;
267                                         pCifsInode->clientCanCacheRead = TRUE;
268                                         cFYI(1,("Exclusive Oplock for inode %p",
269                                                 newinode));
270                                 } else if((oplock & 0xF) == OPLOCK_READ)
271                                         pCifsInode->clientCanCacheRead = TRUE;
272                         }
273                         write_unlock(&GlobalSMBSeslock);
274                 }
275         } 
276 cifs_create_out:
277         kfree(buf);
278         kfree(full_path);
279         FreeXid(xid);
280         return rc;
281 }
282
283 int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode, dev_t device_number) 
284 {
285         int rc = -EPERM;
286         int xid;
287         struct cifs_sb_info *cifs_sb;
288         struct cifsTconInfo *pTcon;
289         char *full_path = NULL;
290         struct inode * newinode = NULL;
291
292         if (!old_valid_dev(device_number))
293                 return -EINVAL;
294
295         xid = GetXid();
296
297         cifs_sb = CIFS_SB(inode->i_sb);
298         pTcon = cifs_sb->tcon;
299
300         down(&direntry->d_sb->s_vfs_rename_sem);
301         full_path = build_path_from_dentry(direntry);
302         up(&direntry->d_sb->s_vfs_rename_sem);
303         if(full_path == NULL)
304                 rc = -ENOMEM;
305         
306         if (full_path && (pTcon->ses->capabilities & CAP_UNIX)) {
307                 if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
308                         rc = CIFSSMBUnixSetPerms(xid, pTcon, full_path,
309                                 mode,(__u64)current->euid,(__u64)current->egid,
310                                 device_number, cifs_sb->local_nls,
311                                 cifs_sb->mnt_cifs_flags & 
312                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
313                 } else {
314                         rc = CIFSSMBUnixSetPerms(xid, pTcon,
315                                 full_path, mode, (__u64)-1, (__u64)-1,
316                                 device_number, cifs_sb->local_nls,
317                                 cifs_sb->mnt_cifs_flags & 
318                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
319                 }
320
321                 if(!rc) {
322                         rc = cifs_get_inode_info_unix(&newinode, full_path,
323                                                 inode->i_sb,xid);
324                         direntry->d_op = &cifs_dentry_ops;
325                         if(rc == 0)
326                                 d_instantiate(direntry, newinode);
327                 }
328         }
329
330         kfree(full_path);
331         FreeXid(xid);
332         return rc;
333 }
334
335
336 struct dentry *
337 cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry, struct nameidata *nd)
338 {
339         int xid;
340         int rc = 0; /* to get around spurious gcc warning, set to zero here */
341         struct cifs_sb_info *cifs_sb;
342         struct cifsTconInfo *pTcon;
343         struct inode *newInode = NULL;
344         char *full_path = NULL;
345
346         xid = GetXid();
347
348         cFYI(1,
349              (" parent inode = 0x%p name is: %s and dentry = 0x%p",
350               parent_dir_inode, direntry->d_name.name, direntry));
351
352         /* BB Add check of incoming data - e.g. frame not longer than maximum SMB - let server check the namelen BB */
353
354         /* check whether path exists */
355
356         cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
357         pTcon = cifs_sb->tcon;
358
359         /* can not grab the rename sem here since it would
360         deadlock in the cases (beginning of sys_rename itself)
361         in which we already have the sb rename sem */
362         full_path = build_path_from_dentry(direntry);
363         if(full_path == NULL) {
364                 FreeXid(xid);
365                 return ERR_PTR(-ENOMEM);
366         }
367
368         if (direntry->d_inode != NULL) {
369                 cFYI(1, (" non-NULL inode in lookup"));
370         } else {
371                 cFYI(1, (" NULL inode in lookup"));
372         }
373         cFYI(1,
374              (" Full path: %s inode = 0x%p", full_path, direntry->d_inode));
375
376         if (pTcon->ses->capabilities & CAP_UNIX)
377                 rc = cifs_get_inode_info_unix(&newInode, full_path,
378                                               parent_dir_inode->i_sb,xid);
379         else
380                 rc = cifs_get_inode_info(&newInode, full_path, NULL,
381                                          parent_dir_inode->i_sb,xid);
382
383         if ((rc == 0) && (newInode != NULL)) {
384                 direntry->d_op = &cifs_dentry_ops;
385                 d_add(direntry, newInode);
386
387                 /* since paths are not looked up by component - the parent directories are presumed to be good here */
388                 renew_parental_timestamps(direntry);
389
390         } else if (rc == -ENOENT) {
391                 rc = 0;
392                 d_add(direntry, NULL);
393         } else {
394                 cERROR(1,("Error 0x%x on cifs_get_inode_info in lookup of %s",
395                            rc,full_path));
396                 /* BB special case check for Access Denied - watch security 
397                 exposure of returning dir info implicitly via different rc 
398                 if file exists or not but no access BB */
399         }
400
401         kfree(full_path);
402         FreeXid(xid);
403         return ERR_PTR(rc);
404 }
405
406 static int
407 cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd)
408 {
409         int isValid = 1;
410
411 /*      lock_kernel(); *//* surely we do not want to lock the kernel for a whole network round trip which could take seconds */
412
413         if (direntry->d_inode) {
414                 if (cifs_revalidate(direntry)) {
415                         /* unlock_kernel(); */
416                         return 0;
417                 }
418         } else {
419                 cFYI(1,
420                      ("In cifs_d_revalidate with no inode but name = %s and dentry 0x%p",
421                       direntry->d_name.name, direntry));
422         }
423
424 /*    unlock_kernel(); */
425
426         return isValid;
427 }
428
429 /* static int cifs_d_delete(struct dentry *direntry)
430 {
431         int rc = 0;
432
433         cFYI(1, ("In cifs d_delete, name = %s", direntry->d_name.name));
434
435         return rc;
436 }     */
437
438 struct dentry_operations cifs_dentry_ops = {
439         .d_revalidate = cifs_d_revalidate,
440 /* d_delete:       cifs_d_delete,       *//* not needed except for debugging */
441         /* no need for d_hash, d_compare, d_release, d_iput ... yet. BB confirm this BB */
442 };