3f3538d4a1fad105c0a776ef5f6d6e18fef0ff6c
[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) {
149                 if ((nd->intent.open.flags & O_ACCMODE) == O_RDONLY)
150                         desiredAccess = GENERIC_READ;
151                 else if ((nd->intent.open.flags & O_ACCMODE) == O_WRONLY) {
152                         desiredAccess = GENERIC_WRITE;
153                         write_only = TRUE;
154                 } else if ((nd->intent.open.flags & O_ACCMODE) == O_RDWR) {
155                         /* GENERIC_ALL is too much permission to request */
156                         /* can cause unnecessary access denied on create */
157                         /* desiredAccess = GENERIC_ALL; */
158                         desiredAccess = GENERIC_READ | GENERIC_WRITE;
159                 }
160
161                 if((nd->intent.open.flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
162                         disposition = FILE_CREATE;
163                 else if((nd->intent.open.flags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
164                         disposition = FILE_OVERWRITE_IF;
165                 else if((nd->intent.open.flags & O_CREAT) == O_CREAT)
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,
185                          &fileHandle, &oplock, buf, cifs_sb->local_nls,
186                          cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
187         if (rc) {
188                 cFYI(1, ("cifs_create returned 0x%x ", rc));
189         } else {
190                 /* If Open reported that we actually created a file
191                 then we now have to set the mode if possible */
192                 if ((cifs_sb->tcon->ses->capabilities & CAP_UNIX) &&
193                         (oplock & CIFS_CREATE_ACTION))
194                         if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
195                                 CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
196                                         (__u64)current->euid,
197                                         (__u64)current->egid,
198                                         0 /* dev */,
199                                         cifs_sb->local_nls, 
200                                         cifs_sb->mnt_cifs_flags & 
201                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
202                         } else {
203                                 CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
204                                         (__u64)-1,
205                                         (__u64)-1,
206                                         0 /* dev */,
207                                         cifs_sb->local_nls,
208                                         cifs_sb->mnt_cifs_flags & 
209                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
210                         }
211                 else {
212                         /* BB implement via Windows security descriptors */
213                         /* eg CIFSSMBWinSetPerms(xid,pTcon,full_path,mode,-1,-1,local_nls);*/
214                         /* could set r/o dos attribute if mode & 0222 == 0 */
215                 }
216
217         /* BB server might mask mode so we have to query for Unix case*/
218                 if (pTcon->ses->capabilities & CAP_UNIX)
219                         rc = cifs_get_inode_info_unix(&newinode, full_path,
220                                                  inode->i_sb,xid);
221                 else {
222                         rc = cifs_get_inode_info(&newinode, full_path,
223                                                  buf, inode->i_sb,xid);
224                         if(newinode)
225                                 newinode->i_mode = mode;
226                 }
227
228                 if (rc != 0) {
229                         cFYI(1,("Create worked but get_inode_info failed with rc = %d",
230                               rc));
231                 } else {
232                         direntry->d_op = &cifs_dentry_ops;
233                         d_instantiate(direntry, newinode);
234                 }
235                 if((nd->flags & LOOKUP_OPEN) == FALSE) {
236                         /* mknod case - do not leave file open */
237                         CIFSSMBClose(xid, pTcon, fileHandle);
238                 } else if(newinode) {
239                         pCifsFile =
240                            kmalloc(sizeof (struct cifsFileInfo), GFP_KERNEL);
241                         
242                         if(pCifsFile == NULL)
243                                 goto cifs_create_out;
244                         memset((char *)pCifsFile, 0,
245                                sizeof (struct cifsFileInfo));
246                         pCifsFile->netfid = fileHandle;
247                         pCifsFile->pid = current->tgid;
248                         pCifsFile->pInode = newinode;
249                         pCifsFile->invalidHandle = FALSE;
250                         pCifsFile->closePend     = FALSE;
251                         init_MUTEX(&pCifsFile->fh_sem);
252                         /* set the following in open now 
253                                 pCifsFile->pfile = file; */
254                         write_lock(&GlobalSMBSeslock);
255                         list_add(&pCifsFile->tlist,&pTcon->openFileList);
256                         pCifsInode = CIFS_I(newinode);
257                         if(pCifsInode) {
258                                 /* if readable file instance put first in list*/
259                                 if (write_only == TRUE) {
260                                         list_add_tail(&pCifsFile->flist,
261                                                 &pCifsInode->openFileList);
262                                 } else {
263                                         list_add(&pCifsFile->flist,
264                                                 &pCifsInode->openFileList);
265                                 }
266                                 if((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
267                                         pCifsInode->clientCanCacheAll = TRUE;
268                                         pCifsInode->clientCanCacheRead = TRUE;
269                                         cFYI(1,("Exclusive Oplock for inode %p",
270                                                 newinode));
271                                 } else if((oplock & 0xF) == OPLOCK_READ)
272                                         pCifsInode->clientCanCacheRead = TRUE;
273                         }
274                         write_unlock(&GlobalSMBSeslock);
275                 }
276         } 
277 cifs_create_out:
278         kfree(buf);
279         kfree(full_path);
280         FreeXid(xid);
281         return rc;
282 }
283
284 int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode, dev_t device_number) 
285 {
286         int rc = -EPERM;
287         int xid;
288         struct cifs_sb_info *cifs_sb;
289         struct cifsTconInfo *pTcon;
290         char *full_path = NULL;
291         struct inode * newinode = NULL;
292
293         if (!old_valid_dev(device_number))
294                 return -EINVAL;
295
296         xid = GetXid();
297
298         cifs_sb = CIFS_SB(inode->i_sb);
299         pTcon = cifs_sb->tcon;
300
301         down(&direntry->d_sb->s_vfs_rename_sem);
302         full_path = build_path_from_dentry(direntry);
303         up(&direntry->d_sb->s_vfs_rename_sem);
304         if(full_path == NULL)
305                 rc = -ENOMEM;
306         
307         if (full_path && (pTcon->ses->capabilities & CAP_UNIX)) {
308                 if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
309                         rc = CIFSSMBUnixSetPerms(xid, pTcon, full_path,
310                                 mode,(__u64)current->euid,(__u64)current->egid,
311                                 device_number, cifs_sb->local_nls,
312                                 cifs_sb->mnt_cifs_flags & 
313                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
314                 } else {
315                         rc = CIFSSMBUnixSetPerms(xid, pTcon,
316                                 full_path, mode, (__u64)-1, (__u64)-1,
317                                 device_number, cifs_sb->local_nls,
318                                 cifs_sb->mnt_cifs_flags & 
319                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
320                 }
321
322                 if(!rc) {
323                         rc = cifs_get_inode_info_unix(&newinode, full_path,
324                                                 inode->i_sb,xid);
325                         direntry->d_op = &cifs_dentry_ops;
326                         if(rc == 0)
327                                 d_instantiate(direntry, newinode);
328                 }
329         }
330
331         kfree(full_path);
332         FreeXid(xid);
333         return rc;
334 }
335
336
337 struct dentry *
338 cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry, struct nameidata *nd)
339 {
340         int xid;
341         int rc = 0; /* to get around spurious gcc warning, set to zero here */
342         struct cifs_sb_info *cifs_sb;
343         struct cifsTconInfo *pTcon;
344         struct inode *newInode = NULL;
345         char *full_path = NULL;
346
347         xid = GetXid();
348
349         cFYI(1,
350              (" parent inode = 0x%p name is: %s and dentry = 0x%p",
351               parent_dir_inode, direntry->d_name.name, direntry));
352
353         /* BB Add check of incoming data - e.g. frame not longer than maximum SMB - let server check the namelen BB */
354
355         /* check whether path exists */
356
357         cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
358         pTcon = cifs_sb->tcon;
359
360         /* can not grab the rename sem here since it would
361         deadlock in the cases (beginning of sys_rename itself)
362         in which we already have the sb rename sem */
363         full_path = build_path_from_dentry(direntry);
364         if(full_path == NULL) {
365                 FreeXid(xid);
366                 return ERR_PTR(-ENOMEM);
367         }
368
369         if (direntry->d_inode != NULL) {
370                 cFYI(1, (" non-NULL inode in lookup"));
371         } else {
372                 cFYI(1, (" NULL inode in lookup"));
373         }
374         cFYI(1,
375              (" Full path: %s inode = 0x%p", full_path, direntry->d_inode));
376
377         if (pTcon->ses->capabilities & CAP_UNIX)
378                 rc = cifs_get_inode_info_unix(&newInode, full_path,
379                                               parent_dir_inode->i_sb,xid);
380         else
381                 rc = cifs_get_inode_info(&newInode, full_path, NULL,
382                                          parent_dir_inode->i_sb,xid);
383
384         if ((rc == 0) && (newInode != NULL)) {
385                 direntry->d_op = &cifs_dentry_ops;
386                 d_add(direntry, newInode);
387
388                 /* since paths are not looked up by component - the parent directories are presumed to be good here */
389                 renew_parental_timestamps(direntry);
390
391         } else if (rc == -ENOENT) {
392                 rc = 0;
393                 d_add(direntry, NULL);
394         } else {
395                 cERROR(1,("Error 0x%x on cifs_get_inode_info in lookup of %s",
396                            rc,full_path));
397                 /* BB special case check for Access Denied - watch security 
398                 exposure of returning dir info implicitly via different rc 
399                 if file exists or not but no access BB */
400         }
401
402         kfree(full_path);
403         FreeXid(xid);
404         return ERR_PTR(rc);
405 }
406
407 static int
408 cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd)
409 {
410         int isValid = 1;
411
412 /*      lock_kernel(); *//* surely we do not want to lock the kernel for a whole network round trip which could take seconds */
413
414         if (direntry->d_inode) {
415                 if (cifs_revalidate(direntry)) {
416                         /* unlock_kernel(); */
417                         return 0;
418                 }
419         } else {
420                 cFYI(1,
421                      ("In cifs_d_revalidate with no inode but name = %s and dentry 0x%p",
422                       direntry->d_name.name, direntry));
423         }
424
425 /*    unlock_kernel(); */
426
427         return isValid;
428 }
429
430 /* static int cifs_d_delete(struct dentry *direntry)
431 {
432         int rc = 0;
433
434         cFYI(1, ("In cifs d_delete, name = %s", direntry->d_name.name));
435
436         return rc;
437 }     */
438
439 struct dentry_operations cifs_dentry_ops = {
440         .d_revalidate = cifs_d_revalidate,
441 /* d_delete:       cifs_d_delete,       *//* not needed except for debugging */
442         /* no need for d_hash, d_compare, d_release, d_iput ... yet. BB confirm this BB */
443 };