1 /*
2 * fs/cifs/dir.c
3 *
4 * vfs operations that deal with dentries
5 *
6 * Copyright (C) International Business Machines Corp., 2002,2009
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 <linux/mount.h>
28 #include <linux/file.h>
29 #include "cifsfs.h"
30 #include "cifspdu.h"
31 #include "cifsglob.h"
32 #include "cifsproto.h"
33 #include "cifs_debug.h"
34 #include "cifs_fs_sb.h"
35 #include "cifs_unicode.h"
36
37 static void
renew_parental_timestamps(struct dentry * direntry)38 renew_parental_timestamps(struct dentry *direntry)
39 {
40 /* BB check if there is a way to get the kernel to do this or if we
41 really need this */
42 do {
43 cifs_set_time(direntry, jiffies);
44 direntry = direntry->d_parent;
45 } while (!IS_ROOT(direntry));
46 }
47
48 char *
cifs_build_path_to_root(struct smb_vol * vol,struct cifs_sb_info * cifs_sb,struct cifs_tcon * tcon,int add_treename)49 cifs_build_path_to_root(struct smb_vol *vol, struct cifs_sb_info *cifs_sb,
50 struct cifs_tcon *tcon, int add_treename)
51 {
52 int pplen = vol->prepath ? strlen(vol->prepath) + 1 : 0;
53 int dfsplen;
54 char *full_path = NULL;
55
56 /* if no prefix path, simply set path to the root of share to "" */
57 if (pplen == 0) {
58 full_path = kzalloc(1, GFP_KERNEL);
59 return full_path;
60 }
61
62 if (add_treename)
63 dfsplen = strnlen(tcon->treeName, MAX_TREE_SIZE + 1);
64 else
65 dfsplen = 0;
66
67 full_path = kmalloc(dfsplen + pplen + 1, GFP_KERNEL);
68 if (full_path == NULL)
69 return full_path;
70
71 if (dfsplen)
72 memcpy(full_path, tcon->treeName, dfsplen);
73 full_path[dfsplen] = CIFS_DIR_SEP(cifs_sb);
74 memcpy(full_path + dfsplen + 1, vol->prepath, pplen);
75 convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb));
76 return full_path;
77 }
78
79 /* Note: caller must free return buffer */
80 char *
build_path_from_dentry(struct dentry * direntry)81 build_path_from_dentry(struct dentry *direntry)
82 {
83 struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
84 struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
85 bool prefix = tcon->Flags & SMB_SHARE_IS_IN_DFS;
86
87 return build_path_from_dentry_optional_prefix(direntry,
88 prefix);
89 }
90
91 char *
build_path_from_dentry_optional_prefix(struct dentry * direntry,bool prefix)92 build_path_from_dentry_optional_prefix(struct dentry *direntry, bool prefix)
93 {
94 struct dentry *temp;
95 int namelen;
96 int dfsplen;
97 int pplen = 0;
98 char *full_path;
99 char dirsep;
100 struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
101 struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
102 unsigned seq;
103
104 dirsep = CIFS_DIR_SEP(cifs_sb);
105 if (prefix)
106 dfsplen = strnlen(tcon->treeName, MAX_TREE_SIZE + 1);
107 else
108 dfsplen = 0;
109
110 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH)
111 pplen = cifs_sb->prepath ? strlen(cifs_sb->prepath) + 1 : 0;
112
113 cifs_bp_rename_retry:
114 namelen = dfsplen + pplen;
115 seq = read_seqbegin(&rename_lock);
116 rcu_read_lock();
117 for (temp = direntry; !IS_ROOT(temp);) {
118 namelen += (1 + temp->d_name.len);
119 temp = temp->d_parent;
120 if (temp == NULL) {
121 cifs_dbg(VFS, "corrupt dentry\n");
122 rcu_read_unlock();
123 return NULL;
124 }
125 }
126 rcu_read_unlock();
127
128 full_path = kmalloc(namelen+1, GFP_ATOMIC);
129 if (full_path == NULL)
130 return full_path;
131 full_path[namelen] = 0; /* trailing null */
132 rcu_read_lock();
133 for (temp = direntry; !IS_ROOT(temp);) {
134 spin_lock(&temp->d_lock);
135 namelen -= 1 + temp->d_name.len;
136 if (namelen < 0) {
137 spin_unlock(&temp->d_lock);
138 break;
139 } else {
140 full_path[namelen] = dirsep;
141 strncpy(full_path + namelen + 1, temp->d_name.name,
142 temp->d_name.len);
143 cifs_dbg(FYI, "name: %s\n", full_path + namelen);
144 }
145 spin_unlock(&temp->d_lock);
146 temp = temp->d_parent;
147 if (temp == NULL) {
148 cifs_dbg(VFS, "corrupt dentry\n");
149 rcu_read_unlock();
150 kfree(full_path);
151 return NULL;
152 }
153 }
154 rcu_read_unlock();
155 if (namelen != dfsplen + pplen || read_seqretry(&rename_lock, seq)) {
156 cifs_dbg(FYI, "did not end path lookup where expected. namelen=%ddfsplen=%d\n",
157 namelen, dfsplen);
158 /* presumably this is only possible if racing with a rename
159 of one of the parent directories (we can not lock the dentries
160 above us to prevent this, but retrying should be harmless) */
161 kfree(full_path);
162 goto cifs_bp_rename_retry;
163 }
164 /* DIR_SEP already set for byte 0 / vs \ but not for
165 subsequent slashes in prepath which currently must
166 be entered the right way - not sure if there is an alternative
167 since the '\' is a valid posix character so we can not switch
168 those safely to '/' if any are found in the middle of the prepath */
169 /* BB test paths to Windows with '/' in the midst of prepath */
170
171 if (pplen) {
172 int i;
173
174 cifs_dbg(FYI, "using cifs_sb prepath <%s>\n", cifs_sb->prepath);
175 memcpy(full_path+dfsplen+1, cifs_sb->prepath, pplen-1);
176 full_path[dfsplen] = dirsep;
177 for (i = 0; i < pplen-1; i++)
178 if (full_path[dfsplen+1+i] == '/')
179 full_path[dfsplen+1+i] = CIFS_DIR_SEP(cifs_sb);
180 }
181
182 if (dfsplen) {
183 strncpy(full_path, tcon->treeName, dfsplen);
184 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) {
185 int i;
186 for (i = 0; i < dfsplen; i++) {
187 if (full_path[i] == '\\')
188 full_path[i] = '/';
189 }
190 }
191 }
192 return full_path;
193 }
194
195 /*
196 * Don't allow path components longer than the server max.
197 * Don't allow the separator character in a path component.
198 * The VFS will not allow "/", but "\" is allowed by posix.
199 */
200 static int
check_name(struct dentry * direntry,struct cifs_tcon * tcon)201 check_name(struct dentry *direntry, struct cifs_tcon *tcon)
202 {
203 struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
204 int i;
205
206 if (unlikely(tcon->fsAttrInfo.MaxPathNameComponentLength &&
207 direntry->d_name.len >
208 le32_to_cpu(tcon->fsAttrInfo.MaxPathNameComponentLength)))
209 return -ENAMETOOLONG;
210
211 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)) {
212 for (i = 0; i < direntry->d_name.len; i++) {
213 if (direntry->d_name.name[i] == '\\') {
214 cifs_dbg(FYI, "Invalid file name\n");
215 return -EINVAL;
216 }
217 }
218 }
219 return 0;
220 }
221
222
223 /* Inode operations in similar order to how they appear in Linux file fs.h */
224
225 static int
cifs_do_create(struct inode * inode,struct dentry * direntry,unsigned int xid,struct tcon_link * tlink,unsigned oflags,umode_t mode,__u32 * oplock,struct cifs_fid * fid)226 cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid,
227 struct tcon_link *tlink, unsigned oflags, umode_t mode,
228 __u32 *oplock, struct cifs_fid *fid)
229 {
230 int rc = -ENOENT;
231 int create_options = CREATE_NOT_DIR;
232 int desired_access;
233 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
234 struct cifs_tcon *tcon = tlink_tcon(tlink);
235 char *full_path = NULL;
236 FILE_ALL_INFO *buf = NULL;
237 struct inode *newinode = NULL;
238 int disposition;
239 struct TCP_Server_Info *server = tcon->ses->server;
240 struct cifs_open_parms oparms;
241
242 *oplock = 0;
243 if (tcon->ses->server->oplocks)
244 *oplock = REQ_OPLOCK;
245
246 full_path = build_path_from_dentry(direntry);
247 if (!full_path)
248 return -ENOMEM;
249
250 if (tcon->unix_ext && cap_unix(tcon->ses) && !tcon->broken_posix_open &&
251 (CIFS_UNIX_POSIX_PATH_OPS_CAP &
252 le64_to_cpu(tcon->fsUnixInfo.Capability))) {
253 rc = cifs_posix_open(full_path, &newinode, inode->i_sb, mode,
254 oflags, oplock, &fid->netfid, xid);
255 switch (rc) {
256 case 0:
257 if (newinode == NULL) {
258 /* query inode info */
259 goto cifs_create_get_file_info;
260 }
261
262 if (S_ISDIR(newinode->i_mode)) {
263 CIFSSMBClose(xid, tcon, fid->netfid);
264 iput(newinode);
265 rc = -EISDIR;
266 goto out;
267 }
268
269 if (!S_ISREG(newinode->i_mode)) {
270 /*
271 * The server may allow us to open things like
272 * FIFOs, but the client isn't set up to deal
273 * with that. If it's not a regular file, just
274 * close it and proceed as if it were a normal
275 * lookup.
276 */
277 CIFSSMBClose(xid, tcon, fid->netfid);
278 goto cifs_create_get_file_info;
279 }
280 /* success, no need to query */
281 goto cifs_create_set_dentry;
282
283 case -ENOENT:
284 goto cifs_create_get_file_info;
285
286 case -EIO:
287 case -EINVAL:
288 /*
289 * EIO could indicate that (posix open) operation is not
290 * supported, despite what server claimed in capability
291 * negotiation.
292 *
293 * POSIX open in samba versions 3.3.1 and earlier could
294 * incorrectly fail with invalid parameter.
295 */
296 tcon->broken_posix_open = true;
297 break;
298
299 case -EREMOTE:
300 case -EOPNOTSUPP:
301 /*
302 * EREMOTE indicates DFS junction, which is not handled
303 * in posix open. If either that or op not supported
304 * returned, follow the normal lookup.
305 */
306 break;
307
308 default:
309 goto out;
310 }
311 /*
312 * fallthrough to retry, using older open call, this is case
313 * where server does not support this SMB level, and falsely
314 * claims capability (also get here for DFS case which should be
315 * rare for path not covered on files)
316 */
317 }
318
319 desired_access = 0;
320 if (OPEN_FMODE(oflags) & FMODE_READ)
321 desired_access |= GENERIC_READ; /* is this too little? */
322 if (OPEN_FMODE(oflags) & FMODE_WRITE)
323 desired_access |= GENERIC_WRITE;
324
325 disposition = FILE_OVERWRITE_IF;
326 if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
327 disposition = FILE_CREATE;
328 else if ((oflags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
329 disposition = FILE_OVERWRITE_IF;
330 else if ((oflags & O_CREAT) == O_CREAT)
331 disposition = FILE_OPEN_IF;
332 else
333 cifs_dbg(FYI, "Create flag not set in create function\n");
334
335 /*
336 * BB add processing to set equivalent of mode - e.g. via CreateX with
337 * ACLs
338 */
339
340 if (!server->ops->open) {
341 rc = -ENOSYS;
342 goto out;
343 }
344
345 buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
346 if (buf == NULL) {
347 rc = -ENOMEM;
348 goto out;
349 }
350
351 /*
352 * if we're not using unix extensions, see if we need to set
353 * ATTR_READONLY on the create call
354 */
355 if (!tcon->unix_ext && (mode & S_IWUGO) == 0)
356 create_options |= CREATE_OPTION_READONLY;
357
358 oparms.tcon = tcon;
359 oparms.cifs_sb = cifs_sb;
360 oparms.desired_access = desired_access;
361 oparms.create_options = cifs_create_options(cifs_sb, create_options);
362 oparms.disposition = disposition;
363 oparms.path = full_path;
364 oparms.fid = fid;
365 oparms.reconnect = false;
366 oparms.mode = mode;
367 rc = server->ops->open(xid, &oparms, oplock, buf);
368 if (rc) {
369 cifs_dbg(FYI, "cifs_create returned 0x%x\n", rc);
370 goto out;
371 }
372
373 /*
374 * If Open reported that we actually created a file then we now have to
375 * set the mode if possible.
376 */
377 if ((tcon->unix_ext) && (*oplock & CIFS_CREATE_ACTION)) {
378 struct cifs_unix_set_info_args args = {
379 .mode = mode,
380 .ctime = NO_CHANGE_64,
381 .atime = NO_CHANGE_64,
382 .mtime = NO_CHANGE_64,
383 .device = 0,
384 };
385
386 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
387 args.uid = current_fsuid();
388 if (inode->i_mode & S_ISGID)
389 args.gid = inode->i_gid;
390 else
391 args.gid = current_fsgid();
392 } else {
393 args.uid = INVALID_UID; /* no change */
394 args.gid = INVALID_GID; /* no change */
395 }
396 CIFSSMBUnixSetFileInfo(xid, tcon, &args, fid->netfid,
397 current->tgid);
398 } else {
399 /*
400 * BB implement mode setting via Windows security
401 * descriptors e.g.
402 */
403 /* CIFSSMBWinSetPerms(xid,tcon,path,mode,-1,-1,nls);*/
404
405 /* Could set r/o dos attribute if mode & 0222 == 0 */
406 }
407
408 cifs_create_get_file_info:
409 /* server might mask mode so we have to query for it */
410 if (tcon->unix_ext)
411 rc = cifs_get_inode_info_unix(&newinode, full_path, inode->i_sb,
412 xid);
413 else {
414 /* TODO: Add support for calling POSIX query info here, but passing in fid */
415 rc = cifs_get_inode_info(&newinode, full_path, buf, inode->i_sb,
416 xid, fid);
417 if (newinode) {
418 if (server->ops->set_lease_key)
419 server->ops->set_lease_key(newinode, fid);
420 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM)
421 newinode->i_mode = mode;
422 if ((*oplock & CIFS_CREATE_ACTION) &&
423 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID)) {
424 newinode->i_uid = current_fsuid();
425 if (inode->i_mode & S_ISGID)
426 newinode->i_gid = inode->i_gid;
427 else
428 newinode->i_gid = current_fsgid();
429 }
430 }
431 }
432
433 cifs_create_set_dentry:
434 if (rc != 0) {
435 cifs_dbg(FYI, "Create worked, get_inode_info failed rc = %d\n",
436 rc);
437 goto out_err;
438 }
439
440 if (S_ISDIR(newinode->i_mode)) {
441 rc = -EISDIR;
442 goto out_err;
443 }
444
445 d_drop(direntry);
446 d_add(direntry, newinode);
447
448 out:
449 kfree(buf);
450 kfree(full_path);
451 return rc;
452
453 out_err:
454 if (server->ops->close)
455 server->ops->close(xid, tcon, fid);
456 if (newinode)
457 iput(newinode);
458 goto out;
459 }
460
461 int
cifs_atomic_open(struct inode * inode,struct dentry * direntry,struct file * file,unsigned oflags,umode_t mode)462 cifs_atomic_open(struct inode *inode, struct dentry *direntry,
463 struct file *file, unsigned oflags, umode_t mode)
464 {
465 int rc;
466 unsigned int xid;
467 struct tcon_link *tlink;
468 struct cifs_tcon *tcon;
469 struct TCP_Server_Info *server;
470 struct cifs_fid fid;
471 struct cifs_pending_open open;
472 __u32 oplock;
473 struct cifsFileInfo *file_info;
474
475 /*
476 * Posix open is only called (at lookup time) for file create now. For
477 * opens (rather than creates), because we do not know if it is a file
478 * or directory yet, and current Samba no longer allows us to do posix
479 * open on dirs, we could end up wasting an open call on what turns out
480 * to be a dir. For file opens, we wait to call posix open till
481 * cifs_open. It could be added to atomic_open in the future but the
482 * performance tradeoff of the extra network request when EISDIR or
483 * EACCES is returned would have to be weighed against the 50% reduction
484 * in network traffic in the other paths.
485 */
486 if (!(oflags & O_CREAT)) {
487 struct dentry *res;
488
489 /*
490 * Check for hashed negative dentry. We have already revalidated
491 * the dentry and it is fine. No need to perform another lookup.
492 */
493 if (!d_in_lookup(direntry))
494 return -ENOENT;
495
496 res = cifs_lookup(inode, direntry, 0);
497 if (IS_ERR(res))
498 return PTR_ERR(res);
499
500 return finish_no_open(file, res);
501 }
502
503 xid = get_xid();
504
505 cifs_dbg(FYI, "parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
506 inode, direntry, direntry);
507
508 tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
509 if (IS_ERR(tlink)) {
510 rc = PTR_ERR(tlink);
511 goto out_free_xid;
512 }
513
514 tcon = tlink_tcon(tlink);
515
516 rc = check_name(direntry, tcon);
517 if (rc)
518 goto out;
519
520 server = tcon->ses->server;
521
522 if (server->ops->new_lease_key)
523 server->ops->new_lease_key(&fid);
524
525 cifs_add_pending_open(&fid, tlink, &open);
526
527 rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,
528 &oplock, &fid);
529
530 if (rc) {
531 cifs_del_pending_open(&open);
532 goto out;
533 }
534
535 if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
536 file->f_mode |= FMODE_CREATED;
537
538 rc = finish_open(file, direntry, generic_file_open);
539 if (rc) {
540 if (server->ops->close)
541 server->ops->close(xid, tcon, &fid);
542 cifs_del_pending_open(&open);
543 goto out;
544 }
545
546 if (file->f_flags & O_DIRECT &&
547 CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO) {
548 if (CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
549 file->f_op = &cifs_file_direct_nobrl_ops;
550 else
551 file->f_op = &cifs_file_direct_ops;
552 }
553
554 file_info = cifs_new_fileinfo(&fid, file, tlink, oplock);
555 if (file_info == NULL) {
556 if (server->ops->close)
557 server->ops->close(xid, tcon, &fid);
558 cifs_del_pending_open(&open);
559 rc = -ENOMEM;
560 }
561
562 out:
563 cifs_put_tlink(tlink);
564 out_free_xid:
565 free_xid(xid);
566 return rc;
567 }
568
cifs_create(struct inode * inode,struct dentry * direntry,umode_t mode,bool excl)569 int cifs_create(struct inode *inode, struct dentry *direntry, umode_t mode,
570 bool excl)
571 {
572 int rc;
573 unsigned int xid = get_xid();
574 /*
575 * BB below access is probably too much for mknod to request
576 * but we have to do query and setpathinfo so requesting
577 * less could fail (unless we want to request getatr and setatr
578 * permissions (only). At least for POSIX we do not have to
579 * request so much.
580 */
581 unsigned oflags = O_EXCL | O_CREAT | O_RDWR;
582 struct tcon_link *tlink;
583 struct cifs_tcon *tcon;
584 struct TCP_Server_Info *server;
585 struct cifs_fid fid;
586 __u32 oplock;
587
588 cifs_dbg(FYI, "cifs_create parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
589 inode, direntry, direntry);
590
591 tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
592 rc = PTR_ERR(tlink);
593 if (IS_ERR(tlink))
594 goto out_free_xid;
595
596 tcon = tlink_tcon(tlink);
597 server = tcon->ses->server;
598
599 if (server->ops->new_lease_key)
600 server->ops->new_lease_key(&fid);
601
602 rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,
603 &oplock, &fid);
604 if (!rc && server->ops->close)
605 server->ops->close(xid, tcon, &fid);
606
607 cifs_put_tlink(tlink);
608 out_free_xid:
609 free_xid(xid);
610 return rc;
611 }
612
cifs_mknod(struct inode * inode,struct dentry * direntry,umode_t mode,dev_t device_number)613 int cifs_mknod(struct inode *inode, struct dentry *direntry, umode_t mode,
614 dev_t device_number)
615 {
616 int rc = -EPERM;
617 unsigned int xid;
618 struct cifs_sb_info *cifs_sb;
619 struct tcon_link *tlink;
620 struct cifs_tcon *tcon;
621 char *full_path = NULL;
622
623 if (!old_valid_dev(device_number))
624 return -EINVAL;
625
626 cifs_sb = CIFS_SB(inode->i_sb);
627 tlink = cifs_sb_tlink(cifs_sb);
628 if (IS_ERR(tlink))
629 return PTR_ERR(tlink);
630
631 tcon = tlink_tcon(tlink);
632
633 xid = get_xid();
634
635 full_path = build_path_from_dentry(direntry);
636 if (full_path == NULL) {
637 rc = -ENOMEM;
638 goto mknod_out;
639 }
640
641 rc = tcon->ses->server->ops->make_node(xid, inode, direntry, tcon,
642 full_path, mode,
643 device_number);
644
645 mknod_out:
646 kfree(full_path);
647 free_xid(xid);
648 cifs_put_tlink(tlink);
649 return rc;
650 }
651
652 struct dentry *
cifs_lookup(struct inode * parent_dir_inode,struct dentry * direntry,unsigned int flags)653 cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
654 unsigned int flags)
655 {
656 unsigned int xid;
657 int rc = 0; /* to get around spurious gcc warning, set to zero here */
658 struct cifs_sb_info *cifs_sb;
659 struct tcon_link *tlink;
660 struct cifs_tcon *pTcon;
661 struct inode *newInode = NULL;
662 char *full_path = NULL;
663
664 xid = get_xid();
665
666 cifs_dbg(FYI, "parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
667 parent_dir_inode, direntry, direntry);
668
669 /* check whether path exists */
670
671 cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
672 tlink = cifs_sb_tlink(cifs_sb);
673 if (IS_ERR(tlink)) {
674 free_xid(xid);
675 return ERR_CAST(tlink);
676 }
677 pTcon = tlink_tcon(tlink);
678
679 rc = check_name(direntry, pTcon);
680 if (unlikely(rc)) {
681 cifs_put_tlink(tlink);
682 free_xid(xid);
683 return ERR_PTR(rc);
684 }
685
686 /* can not grab the rename sem here since it would
687 deadlock in the cases (beginning of sys_rename itself)
688 in which we already have the sb rename sem */
689 full_path = build_path_from_dentry(direntry);
690 if (full_path == NULL) {
691 cifs_put_tlink(tlink);
692 free_xid(xid);
693 return ERR_PTR(-ENOMEM);
694 }
695
696 if (d_really_is_positive(direntry)) {
697 cifs_dbg(FYI, "non-NULL inode in lookup\n");
698 } else {
699 cifs_dbg(FYI, "NULL inode in lookup\n");
700 }
701 cifs_dbg(FYI, "Full path: %s inode = 0x%p\n",
702 full_path, d_inode(direntry));
703
704 if (pTcon->posix_extensions)
705 rc = smb311_posix_get_inode_info(&newInode, full_path, parent_dir_inode->i_sb, xid);
706 else if (pTcon->unix_ext) {
707 rc = cifs_get_inode_info_unix(&newInode, full_path,
708 parent_dir_inode->i_sb, xid);
709 } else {
710 rc = cifs_get_inode_info(&newInode, full_path, NULL,
711 parent_dir_inode->i_sb, xid, NULL);
712 }
713
714 if (rc == 0) {
715 /* since paths are not looked up by component - the parent
716 directories are presumed to be good here */
717 renew_parental_timestamps(direntry);
718 } else if (rc == -ENOENT) {
719 cifs_set_time(direntry, jiffies);
720 newInode = NULL;
721 } else {
722 if (rc != -EACCES) {
723 cifs_dbg(FYI, "Unexpected lookup error %d\n", rc);
724 /* We special case check for Access Denied - since that
725 is a common return code */
726 }
727 newInode = ERR_PTR(rc);
728 }
729 kfree(full_path);
730 cifs_put_tlink(tlink);
731 free_xid(xid);
732 return d_splice_alias(newInode, direntry);
733 }
734
735 static int
cifs_d_revalidate(struct dentry * direntry,unsigned int flags)736 cifs_d_revalidate(struct dentry *direntry, unsigned int flags)
737 {
738 struct inode *inode;
739 int rc;
740
741 if (flags & LOOKUP_RCU)
742 return -ECHILD;
743
744 if (d_really_is_positive(direntry)) {
745 inode = d_inode(direntry);
746 if ((flags & LOOKUP_REVAL) && !CIFS_CACHE_READ(CIFS_I(inode)))
747 CIFS_I(inode)->time = 0; /* force reval */
748
749 rc = cifs_revalidate_dentry(direntry);
750 if (rc) {
751 cifs_dbg(FYI, "cifs_revalidate_dentry failed with rc=%d", rc);
752 switch (rc) {
753 case -ENOENT:
754 case -ESTALE:
755 /*
756 * Those errors mean the dentry is invalid
757 * (file was deleted or recreated)
758 */
759 return 0;
760 default:
761 /*
762 * Otherwise some unexpected error happened
763 * report it as-is to VFS layer
764 */
765 return rc;
766 }
767 }
768 else {
769 /*
770 * If the inode wasn't known to be a dfs entry when
771 * the dentry was instantiated, such as when created
772 * via ->readdir(), it needs to be set now since the
773 * attributes will have been updated by
774 * cifs_revalidate_dentry().
775 */
776 if (IS_AUTOMOUNT(inode) &&
777 !(direntry->d_flags & DCACHE_NEED_AUTOMOUNT)) {
778 spin_lock(&direntry->d_lock);
779 direntry->d_flags |= DCACHE_NEED_AUTOMOUNT;
780 spin_unlock(&direntry->d_lock);
781 }
782
783 return 1;
784 }
785 }
786
787 /*
788 * This may be nfsd (or something), anyway, we can't see the
789 * intent of this. So, since this can be for creation, drop it.
790 */
791 if (!flags)
792 return 0;
793
794 /*
795 * Drop the negative dentry, in order to make sure to use the
796 * case sensitive name which is specified by user if this is
797 * for creation.
798 */
799 if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
800 return 0;
801
802 if (time_after(jiffies, cifs_get_time(direntry) + HZ) || !lookupCacheEnabled)
803 return 0;
804
805 return 1;
806 }
807
808 /* static int cifs_d_delete(struct dentry *direntry)
809 {
810 int rc = 0;
811
812 cifs_dbg(FYI, "In cifs d_delete, name = %pd\n", direntry);
813
814 return rc;
815 } */
816
817 const struct dentry_operations cifs_dentry_ops = {
818 .d_revalidate = cifs_d_revalidate,
819 .d_automount = cifs_dfs_d_automount,
820 /* d_delete: cifs_d_delete, */ /* not needed except for debugging */
821 };
822
cifs_ci_hash(const struct dentry * dentry,struct qstr * q)823 static int cifs_ci_hash(const struct dentry *dentry, struct qstr *q)
824 {
825 struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls;
826 unsigned long hash;
827 wchar_t c;
828 int i, charlen;
829
830 hash = init_name_hash(dentry);
831 for (i = 0; i < q->len; i += charlen) {
832 charlen = codepage->char2uni(&q->name[i], q->len - i, &c);
833 /* error out if we can't convert the character */
834 if (unlikely(charlen < 0))
835 return charlen;
836 hash = partial_name_hash(cifs_toupper(c), hash);
837 }
838 q->hash = end_name_hash(hash);
839
840 return 0;
841 }
842
cifs_ci_compare(const struct dentry * dentry,unsigned int len,const char * str,const struct qstr * name)843 static int cifs_ci_compare(const struct dentry *dentry,
844 unsigned int len, const char *str, const struct qstr *name)
845 {
846 struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls;
847 wchar_t c1, c2;
848 int i, l1, l2;
849
850 /*
851 * We make the assumption here that uppercase characters in the local
852 * codepage are always the same length as their lowercase counterparts.
853 *
854 * If that's ever not the case, then this will fail to match it.
855 */
856 if (name->len != len)
857 return 1;
858
859 for (i = 0; i < len; i += l1) {
860 /* Convert characters in both strings to UTF-16. */
861 l1 = codepage->char2uni(&str[i], len - i, &c1);
862 l2 = codepage->char2uni(&name->name[i], name->len - i, &c2);
863
864 /*
865 * If we can't convert either character, just declare it to
866 * be 1 byte long and compare the original byte.
867 */
868 if (unlikely(l1 < 0 && l2 < 0)) {
869 if (str[i] != name->name[i])
870 return 1;
871 l1 = 1;
872 continue;
873 }
874
875 /*
876 * Here, we again ass|u|me that upper/lowercase versions of
877 * a character are the same length in the local NLS.
878 */
879 if (l1 != l2)
880 return 1;
881
882 /* Now compare uppercase versions of these characters */
883 if (cifs_toupper(c1) != cifs_toupper(c2))
884 return 1;
885 }
886
887 return 0;
888 }
889
890 const struct dentry_operations cifs_ci_dentry_ops = {
891 .d_revalidate = cifs_d_revalidate,
892 .d_hash = cifs_ci_hash,
893 .d_compare = cifs_ci_compare,
894 .d_automount = cifs_dfs_d_automount,
895 };
896