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 == NULL) {
248 rc = -ENOMEM;
249 goto out;
250 }
251
252 if (tcon->unix_ext && cap_unix(tcon->ses) && !tcon->broken_posix_open &&
253 (CIFS_UNIX_POSIX_PATH_OPS_CAP &
254 le64_to_cpu(tcon->fsUnixInfo.Capability))) {
255 rc = cifs_posix_open(full_path, &newinode, inode->i_sb, mode,
256 oflags, oplock, &fid->netfid, xid);
257 switch (rc) {
258 case 0:
259 if (newinode == NULL) {
260 /* query inode info */
261 goto cifs_create_get_file_info;
262 }
263
264 if (S_ISDIR(newinode->i_mode)) {
265 CIFSSMBClose(xid, tcon, fid->netfid);
266 iput(newinode);
267 rc = -EISDIR;
268 goto out;
269 }
270
271 if (!S_ISREG(newinode->i_mode)) {
272 /*
273 * The server may allow us to open things like
274 * FIFOs, but the client isn't set up to deal
275 * with that. If it's not a regular file, just
276 * close it and proceed as if it were a normal
277 * lookup.
278 */
279 CIFSSMBClose(xid, tcon, fid->netfid);
280 goto cifs_create_get_file_info;
281 }
282 /* success, no need to query */
283 goto cifs_create_set_dentry;
284
285 case -ENOENT:
286 goto cifs_create_get_file_info;
287
288 case -EIO:
289 case -EINVAL:
290 /*
291 * EIO could indicate that (posix open) operation is not
292 * supported, despite what server claimed in capability
293 * negotiation.
294 *
295 * POSIX open in samba versions 3.3.1 and earlier could
296 * incorrectly fail with invalid parameter.
297 */
298 tcon->broken_posix_open = true;
299 break;
300
301 case -EREMOTE:
302 case -EOPNOTSUPP:
303 /*
304 * EREMOTE indicates DFS junction, which is not handled
305 * in posix open. If either that or op not supported
306 * returned, follow the normal lookup.
307 */
308 break;
309
310 default:
311 goto out;
312 }
313 /*
314 * fallthrough to retry, using older open call, this is case
315 * where server does not support this SMB level, and falsely
316 * claims capability (also get here for DFS case which should be
317 * rare for path not covered on files)
318 */
319 }
320
321 desired_access = 0;
322 if (OPEN_FMODE(oflags) & FMODE_READ)
323 desired_access |= GENERIC_READ; /* is this too little? */
324 if (OPEN_FMODE(oflags) & FMODE_WRITE)
325 desired_access |= GENERIC_WRITE;
326
327 disposition = FILE_OVERWRITE_IF;
328 if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
329 disposition = FILE_CREATE;
330 else if ((oflags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
331 disposition = FILE_OVERWRITE_IF;
332 else if ((oflags & O_CREAT) == O_CREAT)
333 disposition = FILE_OPEN_IF;
334 else
335 cifs_dbg(FYI, "Create flag not set in create function\n");
336
337 /*
338 * BB add processing to set equivalent of mode - e.g. via CreateX with
339 * ACLs
340 */
341
342 if (!server->ops->open) {
343 rc = -ENOSYS;
344 goto out;
345 }
346
347 buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
348 if (buf == NULL) {
349 rc = -ENOMEM;
350 goto out;
351 }
352
353 /*
354 * if we're not using unix extensions, see if we need to set
355 * ATTR_READONLY on the create call
356 */
357 if (!tcon->unix_ext && (mode & S_IWUGO) == 0)
358 create_options |= CREATE_OPTION_READONLY;
359
360 oparms.tcon = tcon;
361 oparms.cifs_sb = cifs_sb;
362 oparms.desired_access = desired_access;
363 oparms.create_options = cifs_create_options(cifs_sb, create_options);
364 oparms.disposition = disposition;
365 oparms.path = full_path;
366 oparms.fid = fid;
367 oparms.reconnect = false;
368 oparms.mode = mode;
369 rc = server->ops->open(xid, &oparms, oplock, buf);
370 if (rc) {
371 cifs_dbg(FYI, "cifs_create returned 0x%x\n", rc);
372 goto out;
373 }
374
375 /*
376 * If Open reported that we actually created a file then we now have to
377 * set the mode if possible.
378 */
379 if ((tcon->unix_ext) && (*oplock & CIFS_CREATE_ACTION)) {
380 struct cifs_unix_set_info_args args = {
381 .mode = mode,
382 .ctime = NO_CHANGE_64,
383 .atime = NO_CHANGE_64,
384 .mtime = NO_CHANGE_64,
385 .device = 0,
386 };
387
388 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
389 args.uid = current_fsuid();
390 if (inode->i_mode & S_ISGID)
391 args.gid = inode->i_gid;
392 else
393 args.gid = current_fsgid();
394 } else {
395 args.uid = INVALID_UID; /* no change */
396 args.gid = INVALID_GID; /* no change */
397 }
398 CIFSSMBUnixSetFileInfo(xid, tcon, &args, fid->netfid,
399 current->tgid);
400 } else {
401 /*
402 * BB implement mode setting via Windows security
403 * descriptors e.g.
404 */
405 /* CIFSSMBWinSetPerms(xid,tcon,path,mode,-1,-1,nls);*/
406
407 /* Could set r/o dos attribute if mode & 0222 == 0 */
408 }
409
410 cifs_create_get_file_info:
411 /* server might mask mode so we have to query for it */
412 if (tcon->unix_ext)
413 rc = cifs_get_inode_info_unix(&newinode, full_path, inode->i_sb,
414 xid);
415 else {
416 rc = cifs_get_inode_info(&newinode, full_path, buf, inode->i_sb,
417 xid, fid);
418 if (newinode) {
419 if (server->ops->set_lease_key)
420 server->ops->set_lease_key(newinode, fid);
421 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM)
422 newinode->i_mode = mode;
423 if ((*oplock & CIFS_CREATE_ACTION) &&
424 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID)) {
425 newinode->i_uid = current_fsuid();
426 if (inode->i_mode & S_ISGID)
427 newinode->i_gid = inode->i_gid;
428 else
429 newinode->i_gid = current_fsgid();
430 }
431 }
432 }
433
434 cifs_create_set_dentry:
435 if (rc != 0) {
436 cifs_dbg(FYI, "Create worked, get_inode_info failed rc = %d\n",
437 rc);
438 goto out_err;
439 }
440
441 if (S_ISDIR(newinode->i_mode)) {
442 rc = -EISDIR;
443 goto out_err;
444 }
445
446 d_drop(direntry);
447 d_add(direntry, newinode);
448
449 out:
450 kfree(buf);
451 kfree(full_path);
452 return rc;
453
454 out_err:
455 if (server->ops->close)
456 server->ops->close(xid, tcon, fid);
457 if (newinode)
458 iput(newinode);
459 goto out;
460 }
461
462 int
cifs_atomic_open(struct inode * inode,struct dentry * direntry,struct file * file,unsigned oflags,umode_t mode)463 cifs_atomic_open(struct inode *inode, struct dentry *direntry,
464 struct file *file, unsigned oflags, umode_t mode)
465 {
466 int rc;
467 unsigned int xid;
468 struct tcon_link *tlink;
469 struct cifs_tcon *tcon;
470 struct TCP_Server_Info *server;
471 struct cifs_fid fid;
472 struct cifs_pending_open open;
473 __u32 oplock;
474 struct cifsFileInfo *file_info;
475
476 /*
477 * Posix open is only called (at lookup time) for file create now. For
478 * opens (rather than creates), because we do not know if it is a file
479 * or directory yet, and current Samba no longer allows us to do posix
480 * open on dirs, we could end up wasting an open call on what turns out
481 * to be a dir. For file opens, we wait to call posix open till
482 * cifs_open. It could be added to atomic_open in the future but the
483 * performance tradeoff of the extra network request when EISDIR or
484 * EACCES is returned would have to be weighed against the 50% reduction
485 * in network traffic in the other paths.
486 */
487 if (!(oflags & O_CREAT)) {
488 struct dentry *res;
489
490 /*
491 * Check for hashed negative dentry. We have already revalidated
492 * the dentry and it is fine. No need to perform another lookup.
493 */
494 if (!d_in_lookup(direntry))
495 return -ENOENT;
496
497 res = cifs_lookup(inode, direntry, 0);
498 if (IS_ERR(res))
499 return PTR_ERR(res);
500
501 return finish_no_open(file, res);
502 }
503
504 xid = get_xid();
505
506 cifs_dbg(FYI, "parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
507 inode, direntry, direntry);
508
509 tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
510 if (IS_ERR(tlink)) {
511 rc = PTR_ERR(tlink);
512 goto out_free_xid;
513 }
514
515 tcon = tlink_tcon(tlink);
516
517 rc = check_name(direntry, tcon);
518 if (rc)
519 goto out;
520
521 server = tcon->ses->server;
522
523 if (server->ops->new_lease_key)
524 server->ops->new_lease_key(&fid);
525
526 cifs_add_pending_open(&fid, tlink, &open);
527
528 rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,
529 &oplock, &fid);
530
531 if (rc) {
532 cifs_del_pending_open(&open);
533 goto out;
534 }
535
536 if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
537 file->f_mode |= FMODE_CREATED;
538
539 rc = finish_open(file, direntry, generic_file_open);
540 if (rc) {
541 if (server->ops->close)
542 server->ops->close(xid, tcon, &fid);
543 cifs_del_pending_open(&open);
544 goto out;
545 }
546
547 if (file->f_flags & O_DIRECT &&
548 CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO) {
549 if (CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
550 file->f_op = &cifs_file_direct_nobrl_ops;
551 else
552 file->f_op = &cifs_file_direct_ops;
553 }
554
555 file_info = cifs_new_fileinfo(&fid, file, tlink, oplock);
556 if (file_info == NULL) {
557 if (server->ops->close)
558 server->ops->close(xid, tcon, &fid);
559 cifs_del_pending_open(&open);
560 rc = -ENOMEM;
561 }
562
563 out:
564 cifs_put_tlink(tlink);
565 out_free_xid:
566 free_xid(xid);
567 return rc;
568 }
569
cifs_create(struct inode * inode,struct dentry * direntry,umode_t mode,bool excl)570 int cifs_create(struct inode *inode, struct dentry *direntry, umode_t mode,
571 bool excl)
572 {
573 int rc;
574 unsigned int xid = get_xid();
575 /*
576 * BB below access is probably too much for mknod to request
577 * but we have to do query and setpathinfo so requesting
578 * less could fail (unless we want to request getatr and setatr
579 * permissions (only). At least for POSIX we do not have to
580 * request so much.
581 */
582 unsigned oflags = O_EXCL | O_CREAT | O_RDWR;
583 struct tcon_link *tlink;
584 struct cifs_tcon *tcon;
585 struct TCP_Server_Info *server;
586 struct cifs_fid fid;
587 __u32 oplock;
588
589 cifs_dbg(FYI, "cifs_create parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
590 inode, direntry, direntry);
591
592 tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
593 rc = PTR_ERR(tlink);
594 if (IS_ERR(tlink))
595 goto out_free_xid;
596
597 tcon = tlink_tcon(tlink);
598 server = tcon->ses->server;
599
600 if (server->ops->new_lease_key)
601 server->ops->new_lease_key(&fid);
602
603 rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,
604 &oplock, &fid);
605 if (!rc && server->ops->close)
606 server->ops->close(xid, tcon, &fid);
607
608 cifs_put_tlink(tlink);
609 out_free_xid:
610 free_xid(xid);
611 return rc;
612 }
613
cifs_mknod(struct inode * inode,struct dentry * direntry,umode_t mode,dev_t device_number)614 int cifs_mknod(struct inode *inode, struct dentry *direntry, umode_t mode,
615 dev_t device_number)
616 {
617 int rc = -EPERM;
618 unsigned int xid;
619 struct cifs_sb_info *cifs_sb;
620 struct tcon_link *tlink;
621 struct cifs_tcon *tcon;
622 char *full_path = NULL;
623
624 if (!old_valid_dev(device_number))
625 return -EINVAL;
626
627 cifs_sb = CIFS_SB(inode->i_sb);
628 tlink = cifs_sb_tlink(cifs_sb);
629 if (IS_ERR(tlink))
630 return PTR_ERR(tlink);
631
632 tcon = tlink_tcon(tlink);
633
634 xid = get_xid();
635
636 full_path = build_path_from_dentry(direntry);
637 if (full_path == NULL) {
638 rc = -ENOMEM;
639 goto mknod_out;
640 }
641
642 rc = tcon->ses->server->ops->make_node(xid, inode, direntry, tcon,
643 full_path, mode,
644 device_number);
645
646 mknod_out:
647 kfree(full_path);
648 free_xid(xid);
649 cifs_put_tlink(tlink);
650 return rc;
651 }
652
653 struct dentry *
cifs_lookup(struct inode * parent_dir_inode,struct dentry * direntry,unsigned int flags)654 cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
655 unsigned int flags)
656 {
657 unsigned int xid;
658 int rc = 0; /* to get around spurious gcc warning, set to zero here */
659 struct cifs_sb_info *cifs_sb;
660 struct tcon_link *tlink;
661 struct cifs_tcon *pTcon;
662 struct inode *newInode = NULL;
663 char *full_path = NULL;
664
665 xid = get_xid();
666
667 cifs_dbg(FYI, "parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
668 parent_dir_inode, direntry, direntry);
669
670 /* check whether path exists */
671
672 cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
673 tlink = cifs_sb_tlink(cifs_sb);
674 if (IS_ERR(tlink)) {
675 free_xid(xid);
676 return ERR_CAST(tlink);
677 }
678 pTcon = tlink_tcon(tlink);
679
680 rc = check_name(direntry, pTcon);
681 if (unlikely(rc)) {
682 cifs_put_tlink(tlink);
683 free_xid(xid);
684 return ERR_PTR(rc);
685 }
686
687 /* can not grab the rename sem here since it would
688 deadlock in the cases (beginning of sys_rename itself)
689 in which we already have the sb rename sem */
690 full_path = build_path_from_dentry(direntry);
691 if (full_path == NULL) {
692 cifs_put_tlink(tlink);
693 free_xid(xid);
694 return ERR_PTR(-ENOMEM);
695 }
696
697 if (d_really_is_positive(direntry)) {
698 cifs_dbg(FYI, "non-NULL inode in lookup\n");
699 } else {
700 cifs_dbg(FYI, "NULL inode in lookup\n");
701 }
702 cifs_dbg(FYI, "Full path: %s inode = 0x%p\n",
703 full_path, d_inode(direntry));
704
705 if (pTcon->unix_ext) {
706 rc = cifs_get_inode_info_unix(&newInode, full_path,
707 parent_dir_inode->i_sb, xid);
708 } else {
709 rc = cifs_get_inode_info(&newInode, full_path, NULL,
710 parent_dir_inode->i_sb, xid, NULL);
711 }
712
713 if (rc == 0) {
714 /* since paths are not looked up by component - the parent
715 directories are presumed to be good here */
716 renew_parental_timestamps(direntry);
717 } else if (rc == -ENOENT) {
718 cifs_set_time(direntry, jiffies);
719 newInode = NULL;
720 } else {
721 if (rc != -EACCES) {
722 cifs_dbg(FYI, "Unexpected lookup error %d\n", rc);
723 /* We special case check for Access Denied - since that
724 is a common return code */
725 }
726 newInode = ERR_PTR(rc);
727 }
728 kfree(full_path);
729 cifs_put_tlink(tlink);
730 free_xid(xid);
731 return d_splice_alias(newInode, direntry);
732 }
733
734 static int
cifs_d_revalidate(struct dentry * direntry,unsigned int flags)735 cifs_d_revalidate(struct dentry *direntry, unsigned int flags)
736 {
737 struct inode *inode;
738 int rc;
739
740 if (flags & LOOKUP_RCU)
741 return -ECHILD;
742
743 if (d_really_is_positive(direntry)) {
744 inode = d_inode(direntry);
745 if ((flags & LOOKUP_REVAL) && !CIFS_CACHE_READ(CIFS_I(inode)))
746 CIFS_I(inode)->time = 0; /* force reval */
747
748 rc = cifs_revalidate_dentry(direntry);
749 if (rc) {
750 cifs_dbg(FYI, "cifs_revalidate_dentry failed with rc=%d", rc);
751 switch (rc) {
752 case -ENOENT:
753 case -ESTALE:
754 /*
755 * Those errors mean the dentry is invalid
756 * (file was deleted or recreated)
757 */
758 return 0;
759 default:
760 /*
761 * Otherwise some unexpected error happened
762 * report it as-is to VFS layer
763 */
764 return rc;
765 }
766 }
767 else {
768 /*
769 * If the inode wasn't known to be a dfs entry when
770 * the dentry was instantiated, such as when created
771 * via ->readdir(), it needs to be set now since the
772 * attributes will have been updated by
773 * cifs_revalidate_dentry().
774 */
775 if (IS_AUTOMOUNT(inode) &&
776 !(direntry->d_flags & DCACHE_NEED_AUTOMOUNT)) {
777 spin_lock(&direntry->d_lock);
778 direntry->d_flags |= DCACHE_NEED_AUTOMOUNT;
779 spin_unlock(&direntry->d_lock);
780 }
781
782 return 1;
783 }
784 }
785
786 /*
787 * This may be nfsd (or something), anyway, we can't see the
788 * intent of this. So, since this can be for creation, drop it.
789 */
790 if (!flags)
791 return 0;
792
793 /*
794 * Drop the negative dentry, in order to make sure to use the
795 * case sensitive name which is specified by user if this is
796 * for creation.
797 */
798 if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
799 return 0;
800
801 if (time_after(jiffies, cifs_get_time(direntry) + HZ) || !lookupCacheEnabled)
802 return 0;
803
804 return 1;
805 }
806
807 /* static int cifs_d_delete(struct dentry *direntry)
808 {
809 int rc = 0;
810
811 cifs_dbg(FYI, "In cifs d_delete, name = %pd\n", direntry);
812
813 return rc;
814 } */
815
816 const struct dentry_operations cifs_dentry_ops = {
817 .d_revalidate = cifs_d_revalidate,
818 .d_automount = cifs_dfs_d_automount,
819 /* d_delete: cifs_d_delete, */ /* not needed except for debugging */
820 };
821
cifs_ci_hash(const struct dentry * dentry,struct qstr * q)822 static int cifs_ci_hash(const struct dentry *dentry, struct qstr *q)
823 {
824 struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls;
825 unsigned long hash;
826 wchar_t c;
827 int i, charlen;
828
829 hash = init_name_hash(dentry);
830 for (i = 0; i < q->len; i += charlen) {
831 charlen = codepage->char2uni(&q->name[i], q->len - i, &c);
832 /* error out if we can't convert the character */
833 if (unlikely(charlen < 0))
834 return charlen;
835 hash = partial_name_hash(cifs_toupper(c), hash);
836 }
837 q->hash = end_name_hash(hash);
838
839 return 0;
840 }
841
cifs_ci_compare(const struct dentry * dentry,unsigned int len,const char * str,const struct qstr * name)842 static int cifs_ci_compare(const struct dentry *dentry,
843 unsigned int len, const char *str, const struct qstr *name)
844 {
845 struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls;
846 wchar_t c1, c2;
847 int i, l1, l2;
848
849 /*
850 * We make the assumption here that uppercase characters in the local
851 * codepage are always the same length as their lowercase counterparts.
852 *
853 * If that's ever not the case, then this will fail to match it.
854 */
855 if (name->len != len)
856 return 1;
857
858 for (i = 0; i < len; i += l1) {
859 /* Convert characters in both strings to UTF-16. */
860 l1 = codepage->char2uni(&str[i], len - i, &c1);
861 l2 = codepage->char2uni(&name->name[i], name->len - i, &c2);
862
863 /*
864 * If we can't convert either character, just declare it to
865 * be 1 byte long and compare the original byte.
866 */
867 if (unlikely(l1 < 0 && l2 < 0)) {
868 if (str[i] != name->name[i])
869 return 1;
870 l1 = 1;
871 continue;
872 }
873
874 /*
875 * Here, we again ass|u|me that upper/lowercase versions of
876 * a character are the same length in the local NLS.
877 */
878 if (l1 != l2)
879 return 1;
880
881 /* Now compare uppercase versions of these characters */
882 if (cifs_toupper(c1) != cifs_toupper(c2))
883 return 1;
884 }
885
886 return 0;
887 }
888
889 const struct dentry_operations cifs_ci_dentry_ops = {
890 .d_revalidate = cifs_d_revalidate,
891 .d_hash = cifs_ci_hash,
892 .d_compare = cifs_ci_compare,
893 .d_automount = cifs_dfs_d_automount,
894 };
895