Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
[linux-2.6] / 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., 2002,2008
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 /* Inode operations in similar order to how they appear in 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         full_path = build_path_from_dentry(direntry);
141         if (full_path == NULL) {
142                 FreeXid(xid);
143                 return -ENOMEM;
144         }
145
146         if (nd && (nd->flags & LOOKUP_OPEN)) {
147                 int oflags = nd->intent.open.flags;
148
149                 desiredAccess = 0;
150                 if (oflags & FMODE_READ)
151                         desiredAccess |= GENERIC_READ;
152                 if (oflags & FMODE_WRITE) {
153                         desiredAccess |= GENERIC_WRITE;
154                         if (!(oflags & FMODE_READ))
155                                 write_only = TRUE;
156                 }
157
158                 if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
159                         disposition = FILE_CREATE;
160                 else if ((oflags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
161                         disposition = FILE_OVERWRITE_IF;
162                 else if ((oflags & O_CREAT) == O_CREAT)
163                         disposition = FILE_OPEN_IF;
164                 else
165                         cFYI(1, ("Create flag not set in create function"));
166         }
167
168         /* BB add processing to set equivalent of mode - e.g. via CreateX with
169            ACLs */
170         if (oplockEnabled)
171                 oplock = REQ_OPLOCK;
172
173         buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
174         if (buf == NULL) {
175                 kfree(full_path);
176                 FreeXid(xid);
177                 return -ENOMEM;
178         }
179         if (cifs_sb->tcon->ses->capabilities & CAP_NT_SMBS)
180                 rc = CIFSSMBOpen(xid, pTcon, full_path, disposition,
181                          desiredAccess, CREATE_NOT_DIR,
182                          &fileHandle, &oplock, buf, cifs_sb->local_nls,
183                          cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
184         else
185                 rc = -EIO; /* no NT SMB support fall into legacy open below */
186
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         }
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 ((pTcon->unix_ext) && (oplock & CIFS_CREATE_ACTION)) {
200                         mode &= ~current->fs->umask;
201                         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
202                                 CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
203                                         (__u64)current->fsuid,
204                                         (__u64)current->fsgid,
205                                         0 /* dev */,
206                                         cifs_sb->local_nls,
207                                         cifs_sb->mnt_cifs_flags &
208                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
209                         } else {
210                                 CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
211                                         (__u64)-1,
212                                         (__u64)-1,
213                                         0 /* dev */,
214                                         cifs_sb->local_nls,
215                                         cifs_sb->mnt_cifs_flags &
216                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
217                         }
218                 } else {
219                         /* BB implement mode setting via Windows security
220                            descriptors e.g. */
221                         /* CIFSSMBWinSetPerms(xid,pTcon,path,mode,-1,-1,nls);*/
222
223                         /* Could set r/o dos attribute if mode & 0222 == 0 */
224                 }
225
226                 /* server might mask mode so we have to query for it */
227                 if (pTcon->unix_ext)
228                         rc = cifs_get_inode_info_unix(&newinode, full_path,
229                                                  inode->i_sb, xid);
230                 else {
231                         rc = cifs_get_inode_info(&newinode, full_path,
232                                                  buf, inode->i_sb, xid);
233                         if (newinode) {
234                                 newinode->i_mode = mode;
235                                 if ((oplock & CIFS_CREATE_ACTION) &&
236                                     (cifs_sb->mnt_cifs_flags &
237                                      CIFS_MOUNT_SET_UID)) {
238                                         newinode->i_uid = current->fsuid;
239                                         newinode->i_gid = current->fsgid;
240                                 }
241                         }
242                 }
243
244                 if (rc != 0) {
245                         cFYI(1,
246                              ("Create worked but get_inode_info failed rc = %d",
247                               rc));
248                 } else {
249                         if (pTcon->nocase)
250                                 direntry->d_op = &cifs_ci_dentry_ops;
251                         else
252                                 direntry->d_op = &cifs_dentry_ops;
253                         d_instantiate(direntry, newinode);
254                 }
255                 if ((nd == NULL /* nfsd case - nfs srv does not set nd */) ||
256                         ((nd->flags & LOOKUP_OPEN) == FALSE)) {
257                         /* mknod case - do not leave file open */
258                         CIFSSMBClose(xid, pTcon, fileHandle);
259                 } else if (newinode) {
260                         pCifsFile =
261                            kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
262
263                         if (pCifsFile == NULL)
264                                 goto cifs_create_out;
265                         pCifsFile->netfid = fileHandle;
266                         pCifsFile->pid = current->tgid;
267                         pCifsFile->pInode = newinode;
268                         pCifsFile->invalidHandle = FALSE;
269                         pCifsFile->closePend     = FALSE;
270                         init_MUTEX(&pCifsFile->fh_sem);
271                         mutex_init(&pCifsFile->lock_mutex);
272                         INIT_LIST_HEAD(&pCifsFile->llist);
273                         atomic_set(&pCifsFile->wrtPending, 0);
274
275                         /* set the following in open now
276                                 pCifsFile->pfile = file; */
277                         write_lock(&GlobalSMBSeslock);
278                         list_add(&pCifsFile->tlist, &pTcon->openFileList);
279                         pCifsInode = CIFS_I(newinode);
280                         if (pCifsInode) {
281                                 /* if readable file instance put first in list*/
282                                 if (write_only == TRUE) {
283                                         list_add_tail(&pCifsFile->flist,
284                                                 &pCifsInode->openFileList);
285                                 } else {
286                                         list_add(&pCifsFile->flist,
287                                                 &pCifsInode->openFileList);
288                                 }
289                                 if ((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
290                                         pCifsInode->clientCanCacheAll = TRUE;
291                                         pCifsInode->clientCanCacheRead = TRUE;
292                                         cFYI(1, ("Exclusive Oplock inode %p",
293                                                 newinode));
294                                 } else if ((oplock & 0xF) == OPLOCK_READ)
295                                         pCifsInode->clientCanCacheRead = TRUE;
296                         }
297                         write_unlock(&GlobalSMBSeslock);
298                 }
299         }
300 cifs_create_out:
301         kfree(buf);
302         kfree(full_path);
303         FreeXid(xid);
304         return rc;
305 }
306
307 int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode,
308                 dev_t device_number)
309 {
310         int rc = -EPERM;
311         int xid;
312         struct cifs_sb_info *cifs_sb;
313         struct cifsTconInfo *pTcon;
314         char *full_path = NULL;
315         struct inode *newinode = NULL;
316
317         if (!old_valid_dev(device_number))
318                 return -EINVAL;
319
320         xid = GetXid();
321
322         cifs_sb = CIFS_SB(inode->i_sb);
323         pTcon = cifs_sb->tcon;
324
325         full_path = build_path_from_dentry(direntry);
326         if (full_path == NULL)
327                 rc = -ENOMEM;
328         else if (pTcon->unix_ext) {
329                 mode &= ~current->fs->umask;
330                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
331                         rc = CIFSSMBUnixSetPerms(xid, pTcon, full_path,
332                                 mode, (__u64)current->fsuid,
333                                 (__u64)current->fsgid,
334                                 device_number, cifs_sb->local_nls,
335                                 cifs_sb->mnt_cifs_flags &
336                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
337                 } else {
338                         rc = CIFSSMBUnixSetPerms(xid, pTcon,
339                                 full_path, mode, (__u64)-1, (__u64)-1,
340                                 device_number, cifs_sb->local_nls,
341                                 cifs_sb->mnt_cifs_flags &
342                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
343                 }
344
345                 if (!rc) {
346                         rc = cifs_get_inode_info_unix(&newinode, full_path,
347                                                 inode->i_sb, xid);
348                         if (pTcon->nocase)
349                                 direntry->d_op = &cifs_ci_dentry_ops;
350                         else
351                                 direntry->d_op = &cifs_dentry_ops;
352                         if (rc == 0)
353                                 d_instantiate(direntry, newinode);
354                 }
355         } else {
356                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) {
357                         int oplock = 0;
358                         u16 fileHandle;
359                         FILE_ALL_INFO *buf;
360
361                         cFYI(1, ("sfu compat create special file"));
362
363                         buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
364                         if (buf == NULL) {
365                                 kfree(full_path);
366                                 FreeXid(xid);
367                                 return -ENOMEM;
368                         }
369
370                         rc = CIFSSMBOpen(xid, pTcon, full_path,
371                                          FILE_CREATE, /* fail if exists */
372                                          GENERIC_WRITE /* BB would
373                                           WRITE_OWNER | WRITE_DAC be better? */,
374                                          /* Create a file and set the
375                                             file attribute to SYSTEM */
376                                          CREATE_NOT_DIR | CREATE_OPTION_SPECIAL,
377                                          &fileHandle, &oplock, buf,
378                                          cifs_sb->local_nls,
379                                          cifs_sb->mnt_cifs_flags &
380                                             CIFS_MOUNT_MAP_SPECIAL_CHR);
381
382                         /* BB FIXME - add handling for backlevel servers
383                            which need legacy open and check for all
384                            calls to SMBOpen for fallback to SMBLeagcyOpen */
385                         if (!rc) {
386                                 /* BB Do not bother to decode buf since no
387                                    local inode yet to put timestamps in,
388                                    but we can reuse it safely */
389                                 unsigned int bytes_written;
390                                 struct win_dev *pdev;
391                                 pdev = (struct win_dev *)buf;
392                                 if (S_ISCHR(mode)) {
393                                         memcpy(pdev->type, "IntxCHR", 8);
394                                         pdev->major =
395                                               cpu_to_le64(MAJOR(device_number));
396                                         pdev->minor =
397                                               cpu_to_le64(MINOR(device_number));
398                                         rc = CIFSSMBWrite(xid, pTcon,
399                                                 fileHandle,
400                                                 sizeof(struct win_dev),
401                                                 0, &bytes_written, (char *)pdev,
402                                                 NULL, 0);
403                                 } else if (S_ISBLK(mode)) {
404                                         memcpy(pdev->type, "IntxBLK", 8);
405                                         pdev->major =
406                                               cpu_to_le64(MAJOR(device_number));
407                                         pdev->minor =
408                                               cpu_to_le64(MINOR(device_number));
409                                         rc = CIFSSMBWrite(xid, pTcon,
410                                                 fileHandle,
411                                                 sizeof(struct win_dev),
412                                                 0, &bytes_written, (char *)pdev,
413                                                 NULL, 0);
414                                 } /* else if(S_ISFIFO */
415                                 CIFSSMBClose(xid, pTcon, fileHandle);
416                                 d_drop(direntry);
417                         }
418                         kfree(buf);
419                         /* add code here to set EAs */
420                 }
421         }
422
423         kfree(full_path);
424         FreeXid(xid);
425         return rc;
426 }
427
428
429 struct dentry *
430 cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
431             struct nameidata *nd)
432 {
433         int xid;
434         int rc = 0; /* to get around spurious gcc warning, set to zero here */
435         struct cifs_sb_info *cifs_sb;
436         struct cifsTconInfo *pTcon;
437         struct inode *newInode = NULL;
438         char *full_path = NULL;
439
440         xid = GetXid();
441
442         cFYI(1, (" parent inode = 0x%p name is: %s and dentry = 0x%p",
443               parent_dir_inode, direntry->d_name.name, direntry));
444
445         /* check whether path exists */
446
447         cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
448         pTcon = cifs_sb->tcon;
449
450         /*
451          * Don't allow the separator character in a path component.
452          * The VFS will not allow "/", but "\" is allowed by posix.
453          */
454         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)) {
455                 int i;
456                 for (i = 0; i < direntry->d_name.len; i++)
457                         if (direntry->d_name.name[i] == '\\') {
458                                 cFYI(1, ("Invalid file name"));
459                                 FreeXid(xid);
460                                 return ERR_PTR(-EINVAL);
461                         }
462         }
463
464         /* can not grab the rename sem here since it would
465         deadlock in the cases (beginning of sys_rename itself)
466         in which we already have the sb rename sem */
467         full_path = build_path_from_dentry(direntry);
468         if (full_path == NULL) {
469                 FreeXid(xid);
470                 return ERR_PTR(-ENOMEM);
471         }
472
473         if (direntry->d_inode != NULL) {
474                 cFYI(1, (" non-NULL inode in lookup"));
475         } else {
476                 cFYI(1, (" NULL inode in lookup"));
477         }
478         cFYI(1,
479              (" Full path: %s inode = 0x%p", full_path, direntry->d_inode));
480
481         if (pTcon->unix_ext)
482                 rc = cifs_get_inode_info_unix(&newInode, full_path,
483                                               parent_dir_inode->i_sb, xid);
484         else
485                 rc = cifs_get_inode_info(&newInode, full_path, NULL,
486                                          parent_dir_inode->i_sb, xid);
487
488         if ((rc == 0) && (newInode != NULL)) {
489                 if (pTcon->nocase)
490                         direntry->d_op = &cifs_ci_dentry_ops;
491                 else
492                         direntry->d_op = &cifs_dentry_ops;
493                 d_add(direntry, newInode);
494
495                 /* since paths are not looked up by component - the parent
496                    directories are presumed to be good here */
497                 renew_parental_timestamps(direntry);
498
499         } else if (rc == -ENOENT) {
500                 rc = 0;
501                 direntry->d_time = jiffies;
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, NULL);
507         /*      if it was once a directory (but how can we tell?) we could do
508                 shrink_dcache_parent(direntry); */
509         } else if (rc != -EACCES) {
510                 cERROR(1, ("Unexpected lookup error %d", rc));
511                 /* We special case check for Access Denied - since that
512                 is a common return code */
513         }
514
515         kfree(full_path);
516         FreeXid(xid);
517         return ERR_PTR(rc);
518 }
519
520 static int
521 cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd)
522 {
523         int isValid = 1;
524
525         if (direntry->d_inode) {
526                 if (cifs_revalidate(direntry))
527                         return 0;
528         } else {
529                 cFYI(1, ("neg dentry 0x%p name = %s",
530                          direntry, direntry->d_name.name));
531                 if (time_after(jiffies, direntry->d_time + HZ) ||
532                         !lookupCacheEnabled) {
533                         d_drop(direntry);
534                         isValid = 0;
535                 }
536         }
537
538         return isValid;
539 }
540
541 /* static int cifs_d_delete(struct dentry *direntry)
542 {
543         int rc = 0;
544
545         cFYI(1, ("In cifs d_delete, name = %s", direntry->d_name.name));
546
547         return rc;
548 }     */
549
550 struct dentry_operations cifs_dentry_ops = {
551         .d_revalidate = cifs_d_revalidate,
552 /* d_delete:       cifs_d_delete,      */ /* not needed except for debugging */
553 };
554
555 static int cifs_ci_hash(struct dentry *dentry, struct qstr *q)
556 {
557         struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;
558         unsigned long hash;
559         int i;
560
561         hash = init_name_hash();
562         for (i = 0; i < q->len; i++)
563                 hash = partial_name_hash(nls_tolower(codepage, q->name[i]),
564                                          hash);
565         q->hash = end_name_hash(hash);
566
567         return 0;
568 }
569
570 static int cifs_ci_compare(struct dentry *dentry, struct qstr *a,
571                            struct qstr *b)
572 {
573         struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;
574
575         if ((a->len == b->len) &&
576             (nls_strnicmp(codepage, a->name, b->name, a->len) == 0)) {
577                 /*
578                  * To preserve case, don't let an existing negative dentry's
579                  * case take precedence.  If a is not a negative dentry, this
580                  * should have no side effects
581                  */
582                 memcpy(a->name, b->name, a->len);
583                 return 0;
584         }
585         return 1;
586 }
587
588 struct dentry_operations cifs_ci_dentry_ops = {
589         .d_revalidate = cifs_d_revalidate,
590         .d_hash = cifs_ci_hash,
591         .d_compare = cifs_ci_compare,
592 };