1 // SPDX-License-Identifier: LGPL-2.1
2 /*
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 */
10 #include <linux/fs.h>
11 #include <linux/stat.h>
12 #include <linux/slab.h>
13 #include <linux/namei.h>
14 #include <linux/mount.h>
15 #include <linux/file.h>
16 #include "cifsfs.h"
17 #include "cifspdu.h"
18 #include "cifsglob.h"
19 #include "cifsproto.h"
20 #include "cifs_debug.h"
21 #include "cifs_fs_sb.h"
22 #include "cifs_unicode.h"
23 #include "fs_context.h"
24 #include "cifs_ioctl.h"
25
26 static void
renew_parental_timestamps(struct dentry * direntry)27 renew_parental_timestamps(struct dentry *direntry)
28 {
29 /* BB check if there is a way to get the kernel to do this or if we
30 really need this */
31 do {
32 cifs_set_time(direntry, jiffies);
33 direntry = direntry->d_parent;
34 } while (!IS_ROOT(direntry));
35 }
36
37 char *
cifs_build_path_to_root(struct smb3_fs_context * ctx,struct cifs_sb_info * cifs_sb,struct cifs_tcon * tcon,int add_treename)38 cifs_build_path_to_root(struct smb3_fs_context *ctx, struct cifs_sb_info *cifs_sb,
39 struct cifs_tcon *tcon, int add_treename)
40 {
41 int pplen = ctx->prepath ? strlen(ctx->prepath) + 1 : 0;
42 int dfsplen;
43 char *full_path = NULL;
44
45 /* if no prefix path, simply set path to the root of share to "" */
46 if (pplen == 0) {
47 full_path = kzalloc(1, GFP_KERNEL);
48 return full_path;
49 }
50
51 if (add_treename)
52 dfsplen = strnlen(tcon->treeName, MAX_TREE_SIZE + 1);
53 else
54 dfsplen = 0;
55
56 full_path = kmalloc(dfsplen + pplen + 1, GFP_KERNEL);
57 if (full_path == NULL)
58 return full_path;
59
60 if (dfsplen)
61 memcpy(full_path, tcon->treeName, dfsplen);
62 full_path[dfsplen] = CIFS_DIR_SEP(cifs_sb);
63 memcpy(full_path + dfsplen + 1, ctx->prepath, pplen);
64 convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb));
65 return full_path;
66 }
67
68 /* Note: caller must free return buffer */
69 const char *
build_path_from_dentry(struct dentry * direntry,void * page)70 build_path_from_dentry(struct dentry *direntry, void *page)
71 {
72 struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
73 struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
74 bool prefix = tcon->Flags & SMB_SHARE_IS_IN_DFS;
75
76 return build_path_from_dentry_optional_prefix(direntry, page,
77 prefix);
78 }
79
80 char *
build_path_from_dentry_optional_prefix(struct dentry * direntry,void * page,bool prefix)81 build_path_from_dentry_optional_prefix(struct dentry *direntry, void *page,
82 bool prefix)
83 {
84 int dfsplen;
85 int pplen = 0;
86 struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
87 struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
88 char dirsep = CIFS_DIR_SEP(cifs_sb);
89 char *s;
90
91 if (unlikely(!page))
92 return ERR_PTR(-ENOMEM);
93
94 if (prefix)
95 dfsplen = strnlen(tcon->treeName, MAX_TREE_SIZE + 1);
96 else
97 dfsplen = 0;
98
99 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH)
100 pplen = cifs_sb->prepath ? strlen(cifs_sb->prepath) + 1 : 0;
101
102 s = dentry_path_raw(direntry, page, PATH_MAX);
103 if (IS_ERR(s))
104 return s;
105 if (!s[1]) // for root we want "", not "/"
106 s++;
107 if (s < (char *)page + pplen + dfsplen)
108 return ERR_PTR(-ENAMETOOLONG);
109 if (pplen) {
110 cifs_dbg(FYI, "using cifs_sb prepath <%s>\n", cifs_sb->prepath);
111 s -= pplen;
112 memcpy(s + 1, cifs_sb->prepath, pplen - 1);
113 *s = '/';
114 }
115 if (dirsep != '/') {
116 /* BB test paths to Windows with '/' in the midst of prepath */
117 char *p;
118
119 for (p = s; *p; p++)
120 if (*p == '/')
121 *p = dirsep;
122 }
123 if (dfsplen) {
124 s -= dfsplen;
125 memcpy(s, tcon->treeName, dfsplen);
126 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) {
127 int i;
128 for (i = 0; i < dfsplen; i++) {
129 if (s[i] == '\\')
130 s[i] = '/';
131 }
132 }
133 }
134 return s;
135 }
136
137 /*
138 * Don't allow path components longer than the server max.
139 * Don't allow the separator character in a path component.
140 * The VFS will not allow "/", but "\" is allowed by posix.
141 */
142 static int
check_name(struct dentry * direntry,struct cifs_tcon * tcon)143 check_name(struct dentry *direntry, struct cifs_tcon *tcon)
144 {
145 struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
146 int i;
147
148 if (unlikely(tcon->fsAttrInfo.MaxPathNameComponentLength &&
149 direntry->d_name.len >
150 le32_to_cpu(tcon->fsAttrInfo.MaxPathNameComponentLength)))
151 return -ENAMETOOLONG;
152
153 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)) {
154 for (i = 0; i < direntry->d_name.len; i++) {
155 if (direntry->d_name.name[i] == '\\') {
156 cifs_dbg(FYI, "Invalid file name\n");
157 return -EINVAL;
158 }
159 }
160 }
161 return 0;
162 }
163
164
165 /* Inode operations in similar order to how they appear in Linux file fs.h */
166
167 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)168 cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid,
169 struct tcon_link *tlink, unsigned oflags, umode_t mode,
170 __u32 *oplock, struct cifs_fid *fid)
171 {
172 int rc = -ENOENT;
173 int create_options = CREATE_NOT_DIR;
174 int desired_access;
175 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
176 struct cifs_tcon *tcon = tlink_tcon(tlink);
177 const char *full_path;
178 void *page = alloc_dentry_path();
179 FILE_ALL_INFO *buf = NULL;
180 struct inode *newinode = NULL;
181 int disposition;
182 struct TCP_Server_Info *server = tcon->ses->server;
183 struct cifs_open_parms oparms;
184
185 *oplock = 0;
186 if (tcon->ses->server->oplocks)
187 *oplock = REQ_OPLOCK;
188
189 full_path = build_path_from_dentry(direntry, page);
190 if (IS_ERR(full_path)) {
191 free_dentry_path(page);
192 return PTR_ERR(full_path);
193 }
194
195 if (tcon->unix_ext && cap_unix(tcon->ses) && !tcon->broken_posix_open &&
196 (CIFS_UNIX_POSIX_PATH_OPS_CAP &
197 le64_to_cpu(tcon->fsUnixInfo.Capability))) {
198 rc = cifs_posix_open(full_path, &newinode, inode->i_sb, mode,
199 oflags, oplock, &fid->netfid, xid);
200 switch (rc) {
201 case 0:
202 if (newinode == NULL) {
203 /* query inode info */
204 goto cifs_create_get_file_info;
205 }
206
207 if (S_ISDIR(newinode->i_mode)) {
208 CIFSSMBClose(xid, tcon, fid->netfid);
209 iput(newinode);
210 rc = -EISDIR;
211 goto out;
212 }
213
214 if (!S_ISREG(newinode->i_mode)) {
215 /*
216 * The server may allow us to open things like
217 * FIFOs, but the client isn't set up to deal
218 * with that. If it's not a regular file, just
219 * close it and proceed as if it were a normal
220 * lookup.
221 */
222 CIFSSMBClose(xid, tcon, fid->netfid);
223 goto cifs_create_get_file_info;
224 }
225 /* success, no need to query */
226 goto cifs_create_set_dentry;
227
228 case -ENOENT:
229 goto cifs_create_get_file_info;
230
231 case -EIO:
232 case -EINVAL:
233 /*
234 * EIO could indicate that (posix open) operation is not
235 * supported, despite what server claimed in capability
236 * negotiation.
237 *
238 * POSIX open in samba versions 3.3.1 and earlier could
239 * incorrectly fail with invalid parameter.
240 */
241 tcon->broken_posix_open = true;
242 break;
243
244 case -EREMOTE:
245 case -EOPNOTSUPP:
246 /*
247 * EREMOTE indicates DFS junction, which is not handled
248 * in posix open. If either that or op not supported
249 * returned, follow the normal lookup.
250 */
251 break;
252
253 default:
254 goto out;
255 }
256 /*
257 * fallthrough to retry, using older open call, this is case
258 * where server does not support this SMB level, and falsely
259 * claims capability (also get here for DFS case which should be
260 * rare for path not covered on files)
261 */
262 }
263
264 desired_access = 0;
265 if (OPEN_FMODE(oflags) & FMODE_READ)
266 desired_access |= GENERIC_READ; /* is this too little? */
267 if (OPEN_FMODE(oflags) & FMODE_WRITE)
268 desired_access |= GENERIC_WRITE;
269
270 disposition = FILE_OVERWRITE_IF;
271 if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
272 disposition = FILE_CREATE;
273 else if ((oflags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
274 disposition = FILE_OVERWRITE_IF;
275 else if ((oflags & O_CREAT) == O_CREAT)
276 disposition = FILE_OPEN_IF;
277 else
278 cifs_dbg(FYI, "Create flag not set in create function\n");
279
280 /*
281 * BB add processing to set equivalent of mode - e.g. via CreateX with
282 * ACLs
283 */
284
285 if (!server->ops->open) {
286 rc = -ENOSYS;
287 goto out;
288 }
289
290 buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
291 if (buf == NULL) {
292 rc = -ENOMEM;
293 goto out;
294 }
295
296 /*
297 * if we're not using unix extensions, see if we need to set
298 * ATTR_READONLY on the create call
299 */
300 if (!tcon->unix_ext && (mode & S_IWUGO) == 0)
301 create_options |= CREATE_OPTION_READONLY;
302
303 oparms.tcon = tcon;
304 oparms.cifs_sb = cifs_sb;
305 oparms.desired_access = desired_access;
306 oparms.create_options = cifs_create_options(cifs_sb, create_options);
307 oparms.disposition = disposition;
308 oparms.path = full_path;
309 oparms.fid = fid;
310 oparms.reconnect = false;
311 oparms.mode = mode;
312 rc = server->ops->open(xid, &oparms, oplock, buf);
313 if (rc) {
314 cifs_dbg(FYI, "cifs_create returned 0x%x\n", rc);
315 goto out;
316 }
317
318 /*
319 * If Open reported that we actually created a file then we now have to
320 * set the mode if possible.
321 */
322 if ((tcon->unix_ext) && (*oplock & CIFS_CREATE_ACTION)) {
323 struct cifs_unix_set_info_args args = {
324 .mode = mode,
325 .ctime = NO_CHANGE_64,
326 .atime = NO_CHANGE_64,
327 .mtime = NO_CHANGE_64,
328 .device = 0,
329 };
330
331 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
332 args.uid = current_fsuid();
333 if (inode->i_mode & S_ISGID)
334 args.gid = inode->i_gid;
335 else
336 args.gid = current_fsgid();
337 } else {
338 args.uid = INVALID_UID; /* no change */
339 args.gid = INVALID_GID; /* no change */
340 }
341 CIFSSMBUnixSetFileInfo(xid, tcon, &args, fid->netfid,
342 current->tgid);
343 } else {
344 /*
345 * BB implement mode setting via Windows security
346 * descriptors e.g.
347 */
348 /* CIFSSMBWinSetPerms(xid,tcon,path,mode,-1,-1,nls);*/
349
350 /* Could set r/o dos attribute if mode & 0222 == 0 */
351 }
352
353 cifs_create_get_file_info:
354 /* server might mask mode so we have to query for it */
355 if (tcon->unix_ext)
356 rc = cifs_get_inode_info_unix(&newinode, full_path, inode->i_sb,
357 xid);
358 else {
359 /* TODO: Add support for calling POSIX query info here, but passing in fid */
360 rc = cifs_get_inode_info(&newinode, full_path, buf, inode->i_sb,
361 xid, fid);
362 if (newinode) {
363 if (server->ops->set_lease_key)
364 server->ops->set_lease_key(newinode, fid);
365 if ((*oplock & CIFS_CREATE_ACTION) && S_ISREG(newinode->i_mode)) {
366 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM)
367 newinode->i_mode = mode;
368 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
369 newinode->i_uid = current_fsuid();
370 if (inode->i_mode & S_ISGID)
371 newinode->i_gid = inode->i_gid;
372 else
373 newinode->i_gid = current_fsgid();
374 }
375 }
376 }
377 }
378
379 cifs_create_set_dentry:
380 if (rc != 0) {
381 cifs_dbg(FYI, "Create worked, get_inode_info failed rc = %d\n",
382 rc);
383 goto out_err;
384 }
385
386 if (newinode)
387 if (S_ISDIR(newinode->i_mode)) {
388 rc = -EISDIR;
389 goto out_err;
390 }
391
392 d_drop(direntry);
393 d_add(direntry, newinode);
394
395 out:
396 kfree(buf);
397 free_dentry_path(page);
398 return rc;
399
400 out_err:
401 if (server->ops->close)
402 server->ops->close(xid, tcon, fid);
403 if (newinode)
404 iput(newinode);
405 goto out;
406 }
407
408 int
cifs_atomic_open(struct inode * inode,struct dentry * direntry,struct file * file,unsigned oflags,umode_t mode)409 cifs_atomic_open(struct inode *inode, struct dentry *direntry,
410 struct file *file, unsigned oflags, umode_t mode)
411 {
412 int rc;
413 unsigned int xid;
414 struct tcon_link *tlink;
415 struct cifs_tcon *tcon;
416 struct TCP_Server_Info *server;
417 struct cifs_fid fid;
418 struct cifs_pending_open open;
419 __u32 oplock;
420 struct cifsFileInfo *file_info;
421
422 if (unlikely(cifs_forced_shutdown(CIFS_SB(inode->i_sb))))
423 return -EIO;
424
425 /*
426 * Posix open is only called (at lookup time) for file create now. For
427 * opens (rather than creates), because we do not know if it is a file
428 * or directory yet, and current Samba no longer allows us to do posix
429 * open on dirs, we could end up wasting an open call on what turns out
430 * to be a dir. For file opens, we wait to call posix open till
431 * cifs_open. It could be added to atomic_open in the future but the
432 * performance tradeoff of the extra network request when EISDIR or
433 * EACCES is returned would have to be weighed against the 50% reduction
434 * in network traffic in the other paths.
435 */
436 if (!(oflags & O_CREAT)) {
437 struct dentry *res;
438
439 /*
440 * Check for hashed negative dentry. We have already revalidated
441 * the dentry and it is fine. No need to perform another lookup.
442 */
443 if (!d_in_lookup(direntry))
444 return -ENOENT;
445
446 res = cifs_lookup(inode, direntry, 0);
447 if (IS_ERR(res))
448 return PTR_ERR(res);
449
450 return finish_no_open(file, res);
451 }
452
453 xid = get_xid();
454
455 cifs_dbg(FYI, "parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
456 inode, direntry, direntry);
457
458 tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
459 if (IS_ERR(tlink)) {
460 rc = PTR_ERR(tlink);
461 goto out_free_xid;
462 }
463
464 tcon = tlink_tcon(tlink);
465
466 rc = check_name(direntry, tcon);
467 if (rc)
468 goto out;
469
470 server = tcon->ses->server;
471
472 if (server->ops->new_lease_key)
473 server->ops->new_lease_key(&fid);
474
475 cifs_add_pending_open(&fid, tlink, &open);
476
477 rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,
478 &oplock, &fid);
479
480 if (rc) {
481 cifs_del_pending_open(&open);
482 goto out;
483 }
484
485 if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
486 file->f_mode |= FMODE_CREATED;
487
488 rc = finish_open(file, direntry, generic_file_open);
489 if (rc) {
490 if (server->ops->close)
491 server->ops->close(xid, tcon, &fid);
492 cifs_del_pending_open(&open);
493 goto out;
494 }
495
496 if (file->f_flags & O_DIRECT &&
497 CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO) {
498 if (CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
499 file->f_op = &cifs_file_direct_nobrl_ops;
500 else
501 file->f_op = &cifs_file_direct_ops;
502 }
503
504 file_info = cifs_new_fileinfo(&fid, file, tlink, oplock);
505 if (file_info == NULL) {
506 if (server->ops->close)
507 server->ops->close(xid, tcon, &fid);
508 cifs_del_pending_open(&open);
509 rc = -ENOMEM;
510 }
511
512 out:
513 cifs_put_tlink(tlink);
514 out_free_xid:
515 free_xid(xid);
516 return rc;
517 }
518
cifs_create(struct user_namespace * mnt_userns,struct inode * inode,struct dentry * direntry,umode_t mode,bool excl)519 int cifs_create(struct user_namespace *mnt_userns, struct inode *inode,
520 struct dentry *direntry, umode_t mode, bool excl)
521 {
522 int rc;
523 unsigned int xid = get_xid();
524 /*
525 * BB below access is probably too much for mknod to request
526 * but we have to do query and setpathinfo so requesting
527 * less could fail (unless we want to request getatr and setatr
528 * permissions (only). At least for POSIX we do not have to
529 * request so much.
530 */
531 unsigned oflags = O_EXCL | O_CREAT | O_RDWR;
532 struct tcon_link *tlink;
533 struct cifs_tcon *tcon;
534 struct TCP_Server_Info *server;
535 struct cifs_fid fid;
536 __u32 oplock;
537
538 cifs_dbg(FYI, "cifs_create parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
539 inode, direntry, direntry);
540
541 if (unlikely(cifs_forced_shutdown(CIFS_SB(inode->i_sb)))) {
542 rc = -EIO;
543 goto out_free_xid;
544 }
545
546 tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
547 rc = PTR_ERR(tlink);
548 if (IS_ERR(tlink))
549 goto out_free_xid;
550
551 tcon = tlink_tcon(tlink);
552 server = tcon->ses->server;
553
554 if (server->ops->new_lease_key)
555 server->ops->new_lease_key(&fid);
556
557 rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,
558 &oplock, &fid);
559 if (!rc && server->ops->close)
560 server->ops->close(xid, tcon, &fid);
561
562 cifs_put_tlink(tlink);
563 out_free_xid:
564 free_xid(xid);
565 return rc;
566 }
567
cifs_mknod(struct user_namespace * mnt_userns,struct inode * inode,struct dentry * direntry,umode_t mode,dev_t device_number)568 int cifs_mknod(struct user_namespace *mnt_userns, struct inode *inode,
569 struct dentry *direntry, umode_t mode, dev_t device_number)
570 {
571 int rc = -EPERM;
572 unsigned int xid;
573 struct cifs_sb_info *cifs_sb;
574 struct tcon_link *tlink;
575 struct cifs_tcon *tcon;
576 const char *full_path;
577 void *page;
578
579 if (!old_valid_dev(device_number))
580 return -EINVAL;
581
582 cifs_sb = CIFS_SB(inode->i_sb);
583 if (unlikely(cifs_forced_shutdown(cifs_sb)))
584 return -EIO;
585
586 tlink = cifs_sb_tlink(cifs_sb);
587 if (IS_ERR(tlink))
588 return PTR_ERR(tlink);
589
590 page = alloc_dentry_path();
591 tcon = tlink_tcon(tlink);
592 xid = get_xid();
593
594 full_path = build_path_from_dentry(direntry, page);
595 if (IS_ERR(full_path)) {
596 rc = PTR_ERR(full_path);
597 goto mknod_out;
598 }
599
600 rc = tcon->ses->server->ops->make_node(xid, inode, direntry, tcon,
601 full_path, mode,
602 device_number);
603
604 mknod_out:
605 free_dentry_path(page);
606 free_xid(xid);
607 cifs_put_tlink(tlink);
608 return rc;
609 }
610
611 struct dentry *
cifs_lookup(struct inode * parent_dir_inode,struct dentry * direntry,unsigned int flags)612 cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
613 unsigned int flags)
614 {
615 unsigned int xid;
616 int rc = 0; /* to get around spurious gcc warning, set to zero here */
617 struct cifs_sb_info *cifs_sb;
618 struct tcon_link *tlink;
619 struct cifs_tcon *pTcon;
620 struct inode *newInode = NULL;
621 const char *full_path;
622 void *page;
623 int retry_count = 0;
624
625 xid = get_xid();
626
627 cifs_dbg(FYI, "parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
628 parent_dir_inode, direntry, direntry);
629
630 /* check whether path exists */
631
632 cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
633 tlink = cifs_sb_tlink(cifs_sb);
634 if (IS_ERR(tlink)) {
635 free_xid(xid);
636 return ERR_CAST(tlink);
637 }
638 pTcon = tlink_tcon(tlink);
639
640 rc = check_name(direntry, pTcon);
641 if (unlikely(rc)) {
642 cifs_put_tlink(tlink);
643 free_xid(xid);
644 return ERR_PTR(rc);
645 }
646
647 /* can not grab the rename sem here since it would
648 deadlock in the cases (beginning of sys_rename itself)
649 in which we already have the sb rename sem */
650 page = alloc_dentry_path();
651 full_path = build_path_from_dentry(direntry, page);
652 if (IS_ERR(full_path)) {
653 cifs_put_tlink(tlink);
654 free_xid(xid);
655 free_dentry_path(page);
656 return ERR_CAST(full_path);
657 }
658
659 if (d_really_is_positive(direntry)) {
660 cifs_dbg(FYI, "non-NULL inode in lookup\n");
661 } else {
662 cifs_dbg(FYI, "NULL inode in lookup\n");
663 }
664 cifs_dbg(FYI, "Full path: %s inode = 0x%p\n",
665 full_path, d_inode(direntry));
666
667 again:
668 if (pTcon->posix_extensions)
669 rc = smb311_posix_get_inode_info(&newInode, full_path, parent_dir_inode->i_sb, xid);
670 else if (pTcon->unix_ext) {
671 rc = cifs_get_inode_info_unix(&newInode, full_path,
672 parent_dir_inode->i_sb, xid);
673 } else {
674 rc = cifs_get_inode_info(&newInode, full_path, NULL,
675 parent_dir_inode->i_sb, xid, NULL);
676 }
677
678 if (rc == 0) {
679 /* since paths are not looked up by component - the parent
680 directories are presumed to be good here */
681 renew_parental_timestamps(direntry);
682 } else if (rc == -EAGAIN && retry_count++ < 10) {
683 goto again;
684 } else if (rc == -ENOENT) {
685 cifs_set_time(direntry, jiffies);
686 newInode = NULL;
687 } else {
688 if (rc != -EACCES) {
689 cifs_dbg(FYI, "Unexpected lookup error %d\n", rc);
690 /* We special case check for Access Denied - since that
691 is a common return code */
692 }
693 newInode = ERR_PTR(rc);
694 }
695 free_dentry_path(page);
696 cifs_put_tlink(tlink);
697 free_xid(xid);
698 return d_splice_alias(newInode, direntry);
699 }
700
701 static int
cifs_d_revalidate(struct dentry * direntry,unsigned int flags)702 cifs_d_revalidate(struct dentry *direntry, unsigned int flags)
703 {
704 struct inode *inode;
705 int rc;
706
707 if (flags & LOOKUP_RCU)
708 return -ECHILD;
709
710 if (d_really_is_positive(direntry)) {
711 inode = d_inode(direntry);
712 if ((flags & LOOKUP_REVAL) && !CIFS_CACHE_READ(CIFS_I(inode)))
713 CIFS_I(inode)->time = 0; /* force reval */
714
715 rc = cifs_revalidate_dentry(direntry);
716 if (rc) {
717 cifs_dbg(FYI, "cifs_revalidate_dentry failed with rc=%d", rc);
718 switch (rc) {
719 case -ENOENT:
720 case -ESTALE:
721 /*
722 * Those errors mean the dentry is invalid
723 * (file was deleted or recreated)
724 */
725 return 0;
726 default:
727 /*
728 * Otherwise some unexpected error happened
729 * report it as-is to VFS layer
730 */
731 return rc;
732 }
733 }
734 else {
735 /*
736 * If the inode wasn't known to be a dfs entry when
737 * the dentry was instantiated, such as when created
738 * via ->readdir(), it needs to be set now since the
739 * attributes will have been updated by
740 * cifs_revalidate_dentry().
741 */
742 if (IS_AUTOMOUNT(inode) &&
743 !(direntry->d_flags & DCACHE_NEED_AUTOMOUNT)) {
744 spin_lock(&direntry->d_lock);
745 direntry->d_flags |= DCACHE_NEED_AUTOMOUNT;
746 spin_unlock(&direntry->d_lock);
747 }
748
749 return 1;
750 }
751 }
752
753 /*
754 * This may be nfsd (or something), anyway, we can't see the
755 * intent of this. So, since this can be for creation, drop it.
756 */
757 if (!flags)
758 return 0;
759
760 /*
761 * Drop the negative dentry, in order to make sure to use the
762 * case sensitive name which is specified by user if this is
763 * for creation.
764 */
765 if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
766 return 0;
767
768 if (time_after(jiffies, cifs_get_time(direntry) + HZ) || !lookupCacheEnabled)
769 return 0;
770
771 return 1;
772 }
773
774 /* static int cifs_d_delete(struct dentry *direntry)
775 {
776 int rc = 0;
777
778 cifs_dbg(FYI, "In cifs d_delete, name = %pd\n", direntry);
779
780 return rc;
781 } */
782
783 const struct dentry_operations cifs_dentry_ops = {
784 .d_revalidate = cifs_d_revalidate,
785 .d_automount = cifs_dfs_d_automount,
786 /* d_delete: cifs_d_delete, */ /* not needed except for debugging */
787 };
788
cifs_ci_hash(const struct dentry * dentry,struct qstr * q)789 static int cifs_ci_hash(const struct dentry *dentry, struct qstr *q)
790 {
791 struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls;
792 unsigned long hash;
793 wchar_t c;
794 int i, charlen;
795
796 hash = init_name_hash(dentry);
797 for (i = 0; i < q->len; i += charlen) {
798 charlen = codepage->char2uni(&q->name[i], q->len - i, &c);
799 /* error out if we can't convert the character */
800 if (unlikely(charlen < 0))
801 return charlen;
802 hash = partial_name_hash(cifs_toupper(c), hash);
803 }
804 q->hash = end_name_hash(hash);
805
806 return 0;
807 }
808
cifs_ci_compare(const struct dentry * dentry,unsigned int len,const char * str,const struct qstr * name)809 static int cifs_ci_compare(const struct dentry *dentry,
810 unsigned int len, const char *str, const struct qstr *name)
811 {
812 struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls;
813 wchar_t c1, c2;
814 int i, l1, l2;
815
816 /*
817 * We make the assumption here that uppercase characters in the local
818 * codepage are always the same length as their lowercase counterparts.
819 *
820 * If that's ever not the case, then this will fail to match it.
821 */
822 if (name->len != len)
823 return 1;
824
825 for (i = 0; i < len; i += l1) {
826 /* Convert characters in both strings to UTF-16. */
827 l1 = codepage->char2uni(&str[i], len - i, &c1);
828 l2 = codepage->char2uni(&name->name[i], name->len - i, &c2);
829
830 /*
831 * If we can't convert either character, just declare it to
832 * be 1 byte long and compare the original byte.
833 */
834 if (unlikely(l1 < 0 && l2 < 0)) {
835 if (str[i] != name->name[i])
836 return 1;
837 l1 = 1;
838 continue;
839 }
840
841 /*
842 * Here, we again ass|u|me that upper/lowercase versions of
843 * a character are the same length in the local NLS.
844 */
845 if (l1 != l2)
846 return 1;
847
848 /* Now compare uppercase versions of these characters */
849 if (cifs_toupper(c1) != cifs_toupper(c2))
850 return 1;
851 }
852
853 return 0;
854 }
855
856 const struct dentry_operations cifs_ci_dentry_ops = {
857 .d_revalidate = cifs_d_revalidate,
858 .d_hash = cifs_ci_hash,
859 .d_compare = cifs_ci_compare,
860 .d_automount = cifs_dfs_d_automount,
861 };
862