bundle up Unix SET_PATH_INFO args into a struct and change name
[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         int dfsplen;
53         char *full_path;
54         char dirsep;
55         struct cifs_sb_info *cifs_sb;
56
57         if (direntry == NULL)
58                 return NULL;  /* not much we can do if dentry is freed and
59                 we need to reopen the file after it was closed implicitly
60                 when the server crashed */
61
62         cifs_sb = CIFS_SB(direntry->d_sb);
63         dirsep = CIFS_DIR_SEP(cifs_sb);
64         pplen = cifs_sb->prepathlen;
65         if (cifs_sb->tcon && (cifs_sb->tcon->Flags & SMB_SHARE_IS_IN_DFS))
66                 dfsplen = strnlen(cifs_sb->tcon->treeName, MAX_TREE_SIZE + 1);
67         else
68                 dfsplen = 0;
69 cifs_bp_rename_retry:
70         namelen = pplen + dfsplen;
71         for (temp = direntry; !IS_ROOT(temp);) {
72                 namelen += (1 + temp->d_name.len);
73                 temp = temp->d_parent;
74                 if (temp == NULL) {
75                         cERROR(1, ("corrupt dentry"));
76                         return NULL;
77                 }
78         }
79
80         full_path = kmalloc(namelen+1, GFP_KERNEL);
81         if (full_path == NULL)
82                 return full_path;
83         full_path[namelen] = 0; /* trailing null */
84         for (temp = direntry; !IS_ROOT(temp);) {
85                 namelen -= 1 + temp->d_name.len;
86                 if (namelen < 0) {
87                         break;
88                 } else {
89                         full_path[namelen] = dirsep;
90                         strncpy(full_path + namelen + 1, temp->d_name.name,
91                                 temp->d_name.len);
92                         cFYI(0, ("name: %s", full_path + namelen));
93                 }
94                 temp = temp->d_parent;
95                 if (temp == NULL) {
96                         cERROR(1, ("corrupt dentry"));
97                         kfree(full_path);
98                         return NULL;
99                 }
100         }
101         if (namelen != pplen + dfsplen) {
102                 cERROR(1,
103                        ("did not end path lookup where expected namelen is %d",
104                         namelen));
105                 /* presumably this is only possible if racing with a rename
106                 of one of the parent directories  (we can not lock the dentries
107                 above us to prevent this, but retrying should be harmless) */
108                 kfree(full_path);
109                 goto cifs_bp_rename_retry;
110         }
111         /* DIR_SEP already set for byte  0 / vs \ but not for
112            subsequent slashes in prepath which currently must
113            be entered the right way - not sure if there is an alternative
114            since the '\' is a valid posix character so we can not switch
115            those safely to '/' if any are found in the middle of the prepath */
116         /* BB test paths to Windows with '/' in the midst of prepath */
117
118         if (dfsplen) {
119                 strncpy(full_path, cifs_sb->tcon->treeName, dfsplen);
120                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) {
121                         int i;
122                         for (i = 0; i < dfsplen; i++) {
123                                 if (full_path[i] == '\\')
124                                         full_path[i] = '/';
125                         }
126                 }
127         }
128         strncpy(full_path + dfsplen, CIFS_SB(direntry->d_sb)->prepath, pplen);
129         return full_path;
130 }
131
132 /* Inode operations in similar order to how they appear in Linux file fs.h */
133
134 int
135 cifs_create(struct inode *inode, struct dentry *direntry, int mode,
136                 struct nameidata *nd)
137 {
138         int rc = -ENOENT;
139         int xid;
140         int create_options = CREATE_NOT_DIR;
141         int oplock = 0;
142         int desiredAccess = GENERIC_READ | GENERIC_WRITE;
143         __u16 fileHandle;
144         struct cifs_sb_info *cifs_sb;
145         struct cifsTconInfo *pTcon;
146         char *full_path = NULL;
147         FILE_ALL_INFO *buf = NULL;
148         struct inode *newinode = NULL;
149         struct cifsFileInfo *pCifsFile = NULL;
150         struct cifsInodeInfo *pCifsInode;
151         int disposition = FILE_OVERWRITE_IF;
152         bool write_only = false;
153
154         xid = GetXid();
155
156         cifs_sb = CIFS_SB(inode->i_sb);
157         pTcon = cifs_sb->tcon;
158
159         full_path = build_path_from_dentry(direntry);
160         if (full_path == NULL) {
161                 FreeXid(xid);
162                 return -ENOMEM;
163         }
164
165         if (nd && (nd->flags & LOOKUP_OPEN)) {
166                 int oflags = nd->intent.open.flags;
167
168                 desiredAccess = 0;
169                 if (oflags & FMODE_READ)
170                         desiredAccess |= GENERIC_READ;
171                 if (oflags & FMODE_WRITE) {
172                         desiredAccess |= GENERIC_WRITE;
173                         if (!(oflags & FMODE_READ))
174                                 write_only = true;
175                 }
176
177                 if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
178                         disposition = FILE_CREATE;
179                 else if ((oflags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
180                         disposition = FILE_OVERWRITE_IF;
181                 else if ((oflags & O_CREAT) == O_CREAT)
182                         disposition = FILE_OPEN_IF;
183                 else
184                         cFYI(1, ("Create flag not set in create function"));
185         }
186
187         /* BB add processing to set equivalent of mode - e.g. via CreateX with
188            ACLs */
189         if (oplockEnabled)
190                 oplock = REQ_OPLOCK;
191
192         buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
193         if (buf == NULL) {
194                 kfree(full_path);
195                 FreeXid(xid);
196                 return -ENOMEM;
197         }
198
199         mode &= ~current->fs->umask;
200
201         /*
202          * if we're not using unix extensions, see if we need to set
203          * ATTR_READONLY on the create call
204          */
205         if (!pTcon->unix_ext && (mode & S_IWUGO) == 0)
206                 create_options |= CREATE_OPTION_READONLY;
207
208         if (cifs_sb->tcon->ses->capabilities & CAP_NT_SMBS)
209                 rc = CIFSSMBOpen(xid, pTcon, full_path, disposition,
210                          desiredAccess, create_options,
211                          &fileHandle, &oplock, buf, cifs_sb->local_nls,
212                          cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
213         else
214                 rc = -EIO; /* no NT SMB support fall into legacy open below */
215
216         if (rc == -EIO) {
217                 /* old server, retry the open legacy style */
218                 rc = SMBLegacyOpen(xid, pTcon, full_path, disposition,
219                         desiredAccess, create_options,
220                         &fileHandle, &oplock, buf, cifs_sb->local_nls,
221                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
222         }
223         if (rc) {
224                 cFYI(1, ("cifs_create returned 0x%x", rc));
225         } else {
226                 /* If Open reported that we actually created a file
227                 then we now have to set the mode if possible */
228                 if ((pTcon->unix_ext) && (oplock & CIFS_CREATE_ACTION)) {
229                         struct cifs_unix_set_info_args args = {
230                                 .mode   = mode,
231                                 .ctime  = NO_CHANGE_64,
232                                 .atime  = NO_CHANGE_64,
233                                 .mtime  = NO_CHANGE_64,
234                                 .device = 0,
235                         };
236
237                         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
238                                 args.uid = (__u64) current->fsuid;
239                                 args.gid = (__u64) current->fsgid;
240                         } else {
241                                 args.uid = NO_CHANGE_64;
242                                 args.gid = NO_CHANGE_64;
243                         }
244
245                         CIFSSMBUnixSetInfo(xid, pTcon, full_path, &args,
246                                 cifs_sb->local_nls,
247                                 cifs_sb->mnt_cifs_flags &
248                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
249                 } else {
250                         /* BB implement mode setting via Windows security
251                            descriptors e.g. */
252                         /* CIFSSMBWinSetPerms(xid,pTcon,path,mode,-1,-1,nls);*/
253
254                         /* Could set r/o dos attribute if mode & 0222 == 0 */
255                 }
256
257                 /* server might mask mode so we have to query for it */
258                 if (pTcon->unix_ext)
259                         rc = cifs_get_inode_info_unix(&newinode, full_path,
260                                                  inode->i_sb, xid);
261                 else {
262                         rc = cifs_get_inode_info(&newinode, full_path,
263                                                  buf, inode->i_sb, xid,
264                                                  &fileHandle);
265                         if (newinode) {
266                                 if (cifs_sb->mnt_cifs_flags &
267                                     CIFS_MOUNT_DYNPERM)
268                                         newinode->i_mode = mode;
269                                 if ((oplock & CIFS_CREATE_ACTION) &&
270                                     (cifs_sb->mnt_cifs_flags &
271                                      CIFS_MOUNT_SET_UID)) {
272                                         newinode->i_uid = current->fsuid;
273                                         newinode->i_gid = current->fsgid;
274                                 }
275                         }
276                 }
277
278                 if (rc != 0) {
279                         cFYI(1,
280                              ("Create worked but get_inode_info failed rc = %d",
281                               rc));
282                 } else {
283                         if (pTcon->nocase)
284                                 direntry->d_op = &cifs_ci_dentry_ops;
285                         else
286                                 direntry->d_op = &cifs_dentry_ops;
287                         d_instantiate(direntry, newinode);
288                 }
289                 if ((nd == NULL /* nfsd case - nfs srv does not set nd */) ||
290                         (!(nd->flags & LOOKUP_OPEN))) {
291                         /* mknod case - do not leave file open */
292                         CIFSSMBClose(xid, pTcon, fileHandle);
293                 } else if (newinode) {
294                         pCifsFile =
295                            kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
296
297                         if (pCifsFile == NULL)
298                                 goto cifs_create_out;
299                         pCifsFile->netfid = fileHandle;
300                         pCifsFile->pid = current->tgid;
301                         pCifsFile->pInode = newinode;
302                         pCifsFile->invalidHandle = false;
303                         pCifsFile->closePend     = false;
304                         init_MUTEX(&pCifsFile->fh_sem);
305                         mutex_init(&pCifsFile->lock_mutex);
306                         INIT_LIST_HEAD(&pCifsFile->llist);
307                         atomic_set(&pCifsFile->wrtPending, 0);
308
309                         /* set the following in open now
310                                 pCifsFile->pfile = file; */
311                         write_lock(&GlobalSMBSeslock);
312                         list_add(&pCifsFile->tlist, &pTcon->openFileList);
313                         pCifsInode = CIFS_I(newinode);
314                         if (pCifsInode) {
315                                 /* if readable file instance put first in list*/
316                                 if (write_only) {
317                                         list_add_tail(&pCifsFile->flist,
318                                                 &pCifsInode->openFileList);
319                                 } else {
320                                         list_add(&pCifsFile->flist,
321                                                 &pCifsInode->openFileList);
322                                 }
323                                 if ((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
324                                         pCifsInode->clientCanCacheAll = true;
325                                         pCifsInode->clientCanCacheRead = true;
326                                         cFYI(1, ("Exclusive Oplock inode %p",
327                                                 newinode));
328                                 } else if ((oplock & 0xF) == OPLOCK_READ)
329                                         pCifsInode->clientCanCacheRead = true;
330                         }
331                         write_unlock(&GlobalSMBSeslock);
332                 }
333         }
334 cifs_create_out:
335         kfree(buf);
336         kfree(full_path);
337         FreeXid(xid);
338         return rc;
339 }
340
341 int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode,
342                 dev_t device_number)
343 {
344         int rc = -EPERM;
345         int xid;
346         struct cifs_sb_info *cifs_sb;
347         struct cifsTconInfo *pTcon;
348         char *full_path = NULL;
349         struct inode *newinode = NULL;
350
351         if (!old_valid_dev(device_number))
352                 return -EINVAL;
353
354         xid = GetXid();
355
356         cifs_sb = CIFS_SB(inode->i_sb);
357         pTcon = cifs_sb->tcon;
358
359         full_path = build_path_from_dentry(direntry);
360         if (full_path == NULL)
361                 rc = -ENOMEM;
362         else if (pTcon->unix_ext) {
363                 struct cifs_unix_set_info_args args = {
364                         .mode   = mode & ~current->fs->umask,
365                         .ctime  = NO_CHANGE_64,
366                         .atime  = NO_CHANGE_64,
367                         .mtime  = NO_CHANGE_64,
368                         .device = device_number,
369                 };
370                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
371                         args.uid = (__u64) current->fsuid;
372                         args.gid = (__u64) current->fsgid;
373                 } else {
374                         args.uid = NO_CHANGE_64;
375                         args.gid = NO_CHANGE_64;
376                 }
377                 rc = CIFSSMBUnixSetInfo(xid, pTcon, full_path,
378                         &args, cifs_sb->local_nls,
379                         cifs_sb->mnt_cifs_flags &
380                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
381
382                 if (!rc) {
383                         rc = cifs_get_inode_info_unix(&newinode, full_path,
384                                                 inode->i_sb, xid);
385                         if (pTcon->nocase)
386                                 direntry->d_op = &cifs_ci_dentry_ops;
387                         else
388                                 direntry->d_op = &cifs_dentry_ops;
389                         if (rc == 0)
390                                 d_instantiate(direntry, newinode);
391                 }
392         } else {
393                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) {
394                         int oplock = 0;
395                         u16 fileHandle;
396                         FILE_ALL_INFO *buf;
397
398                         cFYI(1, ("sfu compat create special file"));
399
400                         buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
401                         if (buf == NULL) {
402                                 kfree(full_path);
403                                 FreeXid(xid);
404                                 return -ENOMEM;
405                         }
406
407                         rc = CIFSSMBOpen(xid, pTcon, full_path,
408                                          FILE_CREATE, /* fail if exists */
409                                          GENERIC_WRITE /* BB would
410                                           WRITE_OWNER | WRITE_DAC be better? */,
411                                          /* Create a file and set the
412                                             file attribute to SYSTEM */
413                                          CREATE_NOT_DIR | CREATE_OPTION_SPECIAL,
414                                          &fileHandle, &oplock, buf,
415                                          cifs_sb->local_nls,
416                                          cifs_sb->mnt_cifs_flags &
417                                             CIFS_MOUNT_MAP_SPECIAL_CHR);
418
419                         /* BB FIXME - add handling for backlevel servers
420                            which need legacy open and check for all
421                            calls to SMBOpen for fallback to SMBLeagcyOpen */
422                         if (!rc) {
423                                 /* BB Do not bother to decode buf since no
424                                    local inode yet to put timestamps in,
425                                    but we can reuse it safely */
426                                 unsigned int bytes_written;
427                                 struct win_dev *pdev;
428                                 pdev = (struct win_dev *)buf;
429                                 if (S_ISCHR(mode)) {
430                                         memcpy(pdev->type, "IntxCHR", 8);
431                                         pdev->major =
432                                               cpu_to_le64(MAJOR(device_number));
433                                         pdev->minor =
434                                               cpu_to_le64(MINOR(device_number));
435                                         rc = CIFSSMBWrite(xid, pTcon,
436                                                 fileHandle,
437                                                 sizeof(struct win_dev),
438                                                 0, &bytes_written, (char *)pdev,
439                                                 NULL, 0);
440                                 } else if (S_ISBLK(mode)) {
441                                         memcpy(pdev->type, "IntxBLK", 8);
442                                         pdev->major =
443                                               cpu_to_le64(MAJOR(device_number));
444                                         pdev->minor =
445                                               cpu_to_le64(MINOR(device_number));
446                                         rc = CIFSSMBWrite(xid, pTcon,
447                                                 fileHandle,
448                                                 sizeof(struct win_dev),
449                                                 0, &bytes_written, (char *)pdev,
450                                                 NULL, 0);
451                                 } /* else if(S_ISFIFO */
452                                 CIFSSMBClose(xid, pTcon, fileHandle);
453                                 d_drop(direntry);
454                         }
455                         kfree(buf);
456                         /* add code here to set EAs */
457                 }
458         }
459
460         kfree(full_path);
461         FreeXid(xid);
462         return rc;
463 }
464
465
466 struct dentry *
467 cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
468             struct nameidata *nd)
469 {
470         int xid;
471         int rc = 0; /* to get around spurious gcc warning, set to zero here */
472         struct cifs_sb_info *cifs_sb;
473         struct cifsTconInfo *pTcon;
474         struct inode *newInode = NULL;
475         char *full_path = NULL;
476
477         xid = GetXid();
478
479         cFYI(1, (" parent inode = 0x%p name is: %s and dentry = 0x%p",
480               parent_dir_inode, direntry->d_name.name, direntry));
481
482         /* check whether path exists */
483
484         cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
485         pTcon = cifs_sb->tcon;
486
487         /*
488          * Don't allow the separator character in a path component.
489          * The VFS will not allow "/", but "\" is allowed by posix.
490          */
491         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)) {
492                 int i;
493                 for (i = 0; i < direntry->d_name.len; i++)
494                         if (direntry->d_name.name[i] == '\\') {
495                                 cFYI(1, ("Invalid file name"));
496                                 FreeXid(xid);
497                                 return ERR_PTR(-EINVAL);
498                         }
499         }
500
501         /* can not grab the rename sem here since it would
502         deadlock in the cases (beginning of sys_rename itself)
503         in which we already have the sb rename sem */
504         full_path = build_path_from_dentry(direntry);
505         if (full_path == NULL) {
506                 FreeXid(xid);
507                 return ERR_PTR(-ENOMEM);
508         }
509
510         if (direntry->d_inode != NULL) {
511                 cFYI(1, (" non-NULL inode in lookup"));
512         } else {
513                 cFYI(1, (" NULL inode in lookup"));
514         }
515         cFYI(1,
516              (" Full path: %s inode = 0x%p", full_path, direntry->d_inode));
517
518         if (pTcon->unix_ext)
519                 rc = cifs_get_inode_info_unix(&newInode, full_path,
520                                               parent_dir_inode->i_sb, xid);
521         else
522                 rc = cifs_get_inode_info(&newInode, full_path, NULL,
523                                          parent_dir_inode->i_sb, xid, NULL);
524
525         if ((rc == 0) && (newInode != NULL)) {
526                 if (pTcon->nocase)
527                         direntry->d_op = &cifs_ci_dentry_ops;
528                 else
529                         direntry->d_op = &cifs_dentry_ops;
530                 d_add(direntry, newInode);
531
532                 /* since paths are not looked up by component - the parent
533                    directories are presumed to be good here */
534                 renew_parental_timestamps(direntry);
535
536         } else if (rc == -ENOENT) {
537                 rc = 0;
538                 direntry->d_time = jiffies;
539                 if (pTcon->nocase)
540                         direntry->d_op = &cifs_ci_dentry_ops;
541                 else
542                         direntry->d_op = &cifs_dentry_ops;
543                 d_add(direntry, NULL);
544         /*      if it was once a directory (but how can we tell?) we could do
545                 shrink_dcache_parent(direntry); */
546         } else if (rc != -EACCES) {
547                 cERROR(1, ("Unexpected lookup error %d", rc));
548                 /* We special case check for Access Denied - since that
549                 is a common return code */
550         }
551
552         kfree(full_path);
553         FreeXid(xid);
554         return ERR_PTR(rc);
555 }
556
557 static int
558 cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd)
559 {
560         int isValid = 1;
561
562         if (direntry->d_inode) {
563                 if (cifs_revalidate(direntry))
564                         return 0;
565         } else {
566                 cFYI(1, ("neg dentry 0x%p name = %s",
567                          direntry, direntry->d_name.name));
568                 if (time_after(jiffies, direntry->d_time + HZ) ||
569                         !lookupCacheEnabled) {
570                         d_drop(direntry);
571                         isValid = 0;
572                 }
573         }
574
575         return isValid;
576 }
577
578 /* static int cifs_d_delete(struct dentry *direntry)
579 {
580         int rc = 0;
581
582         cFYI(1, ("In cifs d_delete, name = %s", direntry->d_name.name));
583
584         return rc;
585 }     */
586
587 struct dentry_operations cifs_dentry_ops = {
588         .d_revalidate = cifs_d_revalidate,
589 /* d_delete:       cifs_d_delete,      */ /* not needed except for debugging */
590 };
591
592 static int cifs_ci_hash(struct dentry *dentry, struct qstr *q)
593 {
594         struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;
595         unsigned long hash;
596         int i;
597
598         hash = init_name_hash();
599         for (i = 0; i < q->len; i++)
600                 hash = partial_name_hash(nls_tolower(codepage, q->name[i]),
601                                          hash);
602         q->hash = end_name_hash(hash);
603
604         return 0;
605 }
606
607 static int cifs_ci_compare(struct dentry *dentry, struct qstr *a,
608                            struct qstr *b)
609 {
610         struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;
611
612         if ((a->len == b->len) &&
613             (nls_strnicmp(codepage, a->name, b->name, a->len) == 0)) {
614                 /*
615                  * To preserve case, don't let an existing negative dentry's
616                  * case take precedence.  If a is not a negative dentry, this
617                  * should have no side effects
618                  */
619                 memcpy((void *)a->name, b->name, a->len);
620                 return 0;
621         }
622         return 1;
623 }
624
625 struct dentry_operations cifs_ci_dentry_ops = {
626         .d_revalidate = cifs_d_revalidate,
627         .d_hash = cifs_ci_hash,
628         .d_compare = cifs_ci_compare,
629 };