xref: /linux/fs/smb/client/dir.c (revision c02ce1735b150cf7c3b43790b48e23dcd17c0d46)
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 #include "fscache.h"
26 
27 static void
28 renew_parental_timestamps(struct dentry *direntry)
29 {
30 	/* BB check if there is a way to get the kernel to do this or if we
31 	   really need this */
32 	do {
33 		cifs_set_time(direntry, jiffies);
34 		direntry = direntry->d_parent;
35 	} while (!IS_ROOT(direntry));
36 }
37 
38 char *
39 cifs_build_path_to_root(struct smb3_fs_context *ctx, struct cifs_sb_info *cifs_sb,
40 			struct cifs_tcon *tcon, int add_treename)
41 {
42 	int pplen = ctx->prepath ? strlen(ctx->prepath) + 1 : 0;
43 	int dfsplen;
44 	char *full_path = NULL;
45 
46 	/* if no prefix path, simply set path to the root of share to "" */
47 	if (pplen == 0) {
48 		full_path = kzalloc(1, GFP_KERNEL);
49 		return full_path;
50 	}
51 
52 	if (add_treename)
53 		dfsplen = strnlen(tcon->tree_name, MAX_TREE_SIZE + 1);
54 	else
55 		dfsplen = 0;
56 
57 	full_path = kmalloc(dfsplen + pplen + 1, GFP_KERNEL);
58 	if (full_path == NULL)
59 		return full_path;
60 
61 	if (dfsplen)
62 		memcpy(full_path, tcon->tree_name, dfsplen);
63 	full_path[dfsplen] = CIFS_DIR_SEP(cifs_sb);
64 	memcpy(full_path + dfsplen + 1, ctx->prepath, pplen);
65 	convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb));
66 	return full_path;
67 }
68 
69 /* Note: caller must free return buffer */
70 const char *
71 build_path_from_dentry(struct dentry *direntry, void *page)
72 {
73 	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
74 	struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
75 	bool prefix = tcon->Flags & SMB_SHARE_IS_IN_DFS;
76 
77 	return build_path_from_dentry_optional_prefix(direntry, page,
78 						      prefix);
79 }
80 
81 char *__build_path_from_dentry_optional_prefix(struct dentry *direntry, void *page,
82 					       const char *tree, int tree_len,
83 					       bool prefix)
84 {
85 	int dfsplen;
86 	int pplen = 0;
87 	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_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(tree, tree_len + 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, tree, 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 char *build_path_from_dentry_optional_prefix(struct dentry *direntry, void *page,
138 					     bool prefix)
139 {
140 	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
141 	struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
142 
143 	return __build_path_from_dentry_optional_prefix(direntry, page, tcon->tree_name,
144 							MAX_TREE_SIZE, prefix);
145 }
146 
147 /*
148  * Don't allow path components longer than the server max.
149  * Don't allow the separator character in a path component.
150  * The VFS will not allow "/", but "\" is allowed by posix.
151  */
152 static int
153 check_name(struct dentry *direntry, struct cifs_tcon *tcon)
154 {
155 	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
156 	int i;
157 
158 	if (unlikely(tcon->fsAttrInfo.MaxPathNameComponentLength &&
159 		     direntry->d_name.len >
160 		     le32_to_cpu(tcon->fsAttrInfo.MaxPathNameComponentLength)))
161 		return -ENAMETOOLONG;
162 
163 	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)) {
164 		for (i = 0; i < direntry->d_name.len; i++) {
165 			if (direntry->d_name.name[i] == '\\') {
166 				cifs_dbg(FYI, "Invalid file name\n");
167 				return -EINVAL;
168 			}
169 		}
170 	}
171 	return 0;
172 }
173 
174 
175 /* Inode operations in similar order to how they appear in Linux file fs.h */
176 
177 static int cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid,
178 			  struct tcon_link *tlink, unsigned int oflags, umode_t mode, __u32 *oplock,
179 			  struct cifs_fid *fid, struct cifs_open_info_data *buf)
180 {
181 	int rc = -ENOENT;
182 	int create_options = CREATE_NOT_DIR;
183 	int desired_access;
184 	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
185 	struct cifs_tcon *tcon = tlink_tcon(tlink);
186 	const char *full_path;
187 	void *page = alloc_dentry_path();
188 	struct inode *newinode = NULL;
189 	int disposition;
190 	struct TCP_Server_Info *server = tcon->ses->server;
191 	struct cifs_open_parms oparms;
192 	int rdwr_for_fscache = 0;
193 
194 	*oplock = 0;
195 	if (tcon->ses->server->oplocks)
196 		*oplock = REQ_OPLOCK;
197 
198 	full_path = build_path_from_dentry(direntry, page);
199 	if (IS_ERR(full_path)) {
200 		free_dentry_path(page);
201 		return PTR_ERR(full_path);
202 	}
203 
204 	/* If we're caching, we need to be able to fill in around partial writes. */
205 	if (cifs_fscache_enabled(inode) && (oflags & O_ACCMODE) == O_WRONLY)
206 		rdwr_for_fscache = 1;
207 
208 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
209 	if (tcon->unix_ext && cap_unix(tcon->ses) && !tcon->broken_posix_open &&
210 	    (CIFS_UNIX_POSIX_PATH_OPS_CAP &
211 			le64_to_cpu(tcon->fsUnixInfo.Capability))) {
212 		rc = cifs_posix_open(full_path, &newinode, inode->i_sb, mode,
213 				     oflags, oplock, &fid->netfid, xid);
214 		switch (rc) {
215 		case 0:
216 			if (newinode == NULL) {
217 				/* query inode info */
218 				goto cifs_create_get_file_info;
219 			}
220 
221 			if (S_ISDIR(newinode->i_mode)) {
222 				CIFSSMBClose(xid, tcon, fid->netfid);
223 				iput(newinode);
224 				rc = -EISDIR;
225 				goto out;
226 			}
227 
228 			if (!S_ISREG(newinode->i_mode)) {
229 				/*
230 				 * The server may allow us to open things like
231 				 * FIFOs, but the client isn't set up to deal
232 				 * with that. If it's not a regular file, just
233 				 * close it and proceed as if it were a normal
234 				 * lookup.
235 				 */
236 				CIFSSMBClose(xid, tcon, fid->netfid);
237 				goto cifs_create_get_file_info;
238 			}
239 			/* success, no need to query */
240 			goto cifs_create_set_dentry;
241 
242 		case -ENOENT:
243 			goto cifs_create_get_file_info;
244 
245 		case -EIO:
246 		case -EINVAL:
247 			/*
248 			 * EIO could indicate that (posix open) operation is not
249 			 * supported, despite what server claimed in capability
250 			 * negotiation.
251 			 *
252 			 * POSIX open in samba versions 3.3.1 and earlier could
253 			 * incorrectly fail with invalid parameter.
254 			 */
255 			tcon->broken_posix_open = true;
256 			break;
257 
258 		case -EREMOTE:
259 		case -EOPNOTSUPP:
260 			/*
261 			 * EREMOTE indicates DFS junction, which is not handled
262 			 * in posix open.  If either that or op not supported
263 			 * returned, follow the normal lookup.
264 			 */
265 			break;
266 
267 		default:
268 			goto out;
269 		}
270 		/*
271 		 * fallthrough to retry, using older open call, this is case
272 		 * where server does not support this SMB level, and falsely
273 		 * claims capability (also get here for DFS case which should be
274 		 * rare for path not covered on files)
275 		 */
276 	}
277 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
278 
279 	desired_access = 0;
280 	if (OPEN_FMODE(oflags) & FMODE_READ)
281 		desired_access |= GENERIC_READ; /* is this too little? */
282 	if (OPEN_FMODE(oflags) & FMODE_WRITE)
283 		desired_access |= GENERIC_WRITE;
284 	if (rdwr_for_fscache == 1)
285 		desired_access |= GENERIC_READ;
286 
287 	disposition = FILE_OVERWRITE_IF;
288 	if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
289 		disposition = FILE_CREATE;
290 	else if ((oflags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
291 		disposition = FILE_OVERWRITE_IF;
292 	else if ((oflags & O_CREAT) == O_CREAT)
293 		disposition = FILE_OPEN_IF;
294 	else
295 		cifs_dbg(FYI, "Create flag not set in create function\n");
296 
297 	/*
298 	 * BB add processing to set equivalent of mode - e.g. via CreateX with
299 	 * ACLs
300 	 */
301 
302 	if (!server->ops->open) {
303 		rc = -ENOSYS;
304 		goto out;
305 	}
306 
307 	/*
308 	 * if we're not using unix extensions, see if we need to set
309 	 * ATTR_READONLY on the create call
310 	 */
311 	if (!tcon->unix_ext && (mode & S_IWUGO) == 0)
312 		create_options |= CREATE_OPTION_READONLY;
313 
314 retry_open:
315 	oparms = (struct cifs_open_parms) {
316 		.tcon = tcon,
317 		.cifs_sb = cifs_sb,
318 		.desired_access = desired_access,
319 		.create_options = cifs_create_options(cifs_sb, create_options),
320 		.disposition = disposition,
321 		.path = full_path,
322 		.fid = fid,
323 		.mode = mode,
324 	};
325 	rc = server->ops->open(xid, &oparms, oplock, buf);
326 	if (rc) {
327 		cifs_dbg(FYI, "cifs_create returned 0x%x\n", rc);
328 		if (rc == -EACCES && rdwr_for_fscache == 1) {
329 			desired_access &= ~GENERIC_READ;
330 			rdwr_for_fscache = 2;
331 			goto retry_open;
332 		}
333 		goto out;
334 	}
335 	if (rdwr_for_fscache == 2)
336 		cifs_invalidate_cache(inode, FSCACHE_INVAL_DIO_WRITE);
337 
338 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
339 	/*
340 	 * If Open reported that we actually created a file then we now have to
341 	 * set the mode if possible.
342 	 */
343 	if ((tcon->unix_ext) && (*oplock & CIFS_CREATE_ACTION)) {
344 		struct cifs_unix_set_info_args args = {
345 				.mode	= mode,
346 				.ctime	= NO_CHANGE_64,
347 				.atime	= NO_CHANGE_64,
348 				.mtime	= NO_CHANGE_64,
349 				.device	= 0,
350 		};
351 
352 		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
353 			args.uid = current_fsuid();
354 			if (inode->i_mode & S_ISGID)
355 				args.gid = inode->i_gid;
356 			else
357 				args.gid = current_fsgid();
358 		} else {
359 			args.uid = INVALID_UID; /* no change */
360 			args.gid = INVALID_GID; /* no change */
361 		}
362 		CIFSSMBUnixSetFileInfo(xid, tcon, &args, fid->netfid,
363 				       current->tgid);
364 	} else {
365 		/*
366 		 * BB implement mode setting via Windows security
367 		 * descriptors e.g.
368 		 */
369 		/* CIFSSMBWinSetPerms(xid,tcon,path,mode,-1,-1,nls);*/
370 
371 		/* Could set r/o dos attribute if mode & 0222 == 0 */
372 	}
373 
374 cifs_create_get_file_info:
375 	/* server might mask mode so we have to query for it */
376 	if (tcon->unix_ext)
377 		rc = cifs_get_inode_info_unix(&newinode, full_path, inode->i_sb,
378 					      xid);
379 	else {
380 #else
381 	{
382 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
383 		/* TODO: Add support for calling POSIX query info here, but passing in fid */
384 		rc = cifs_get_inode_info(&newinode, full_path, buf, inode->i_sb, xid, fid);
385 		if (newinode) {
386 			if (server->ops->set_lease_key)
387 				server->ops->set_lease_key(newinode, fid);
388 			if ((*oplock & CIFS_CREATE_ACTION) && S_ISREG(newinode->i_mode)) {
389 				if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM)
390 					newinode->i_mode = mode;
391 				if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
392 					newinode->i_uid = current_fsuid();
393 					if (inode->i_mode & S_ISGID)
394 						newinode->i_gid = inode->i_gid;
395 					else
396 						newinode->i_gid = current_fsgid();
397 				}
398 			}
399 		}
400 	}
401 
402 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
403 cifs_create_set_dentry:
404 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
405 	if (rc != 0) {
406 		cifs_dbg(FYI, "Create worked, get_inode_info failed rc = %d\n",
407 			 rc);
408 		goto out_err;
409 	}
410 
411 	if (newinode)
412 		if (S_ISDIR(newinode->i_mode)) {
413 			rc = -EISDIR;
414 			goto out_err;
415 		}
416 
417 	d_drop(direntry);
418 	d_add(direntry, newinode);
419 
420 out:
421 	free_dentry_path(page);
422 	return rc;
423 
424 out_err:
425 	if (server->ops->close)
426 		server->ops->close(xid, tcon, fid);
427 	if (newinode)
428 		iput(newinode);
429 	goto out;
430 }
431 
432 int
433 cifs_atomic_open(struct inode *inode, struct dentry *direntry,
434 		 struct file *file, unsigned oflags, umode_t mode)
435 {
436 	int rc;
437 	unsigned int xid;
438 	struct tcon_link *tlink;
439 	struct cifs_tcon *tcon;
440 	struct TCP_Server_Info *server;
441 	struct cifs_fid fid = {};
442 	struct cifs_pending_open open;
443 	__u32 oplock;
444 	struct cifsFileInfo *file_info;
445 	struct cifs_open_info_data buf = {};
446 
447 	if (unlikely(cifs_forced_shutdown(CIFS_SB(inode->i_sb))))
448 		return -EIO;
449 
450 	/*
451 	 * Posix open is only called (at lookup time) for file create now. For
452 	 * opens (rather than creates), because we do not know if it is a file
453 	 * or directory yet, and current Samba no longer allows us to do posix
454 	 * open on dirs, we could end up wasting an open call on what turns out
455 	 * to be a dir. For file opens, we wait to call posix open till
456 	 * cifs_open.  It could be added to atomic_open in the future but the
457 	 * performance tradeoff of the extra network request when EISDIR or
458 	 * EACCES is returned would have to be weighed against the 50% reduction
459 	 * in network traffic in the other paths.
460 	 */
461 	if (!(oflags & O_CREAT)) {
462 		struct dentry *res;
463 
464 		/*
465 		 * Check for hashed negative dentry. We have already revalidated
466 		 * the dentry and it is fine. No need to perform another lookup.
467 		 */
468 		if (!d_in_lookup(direntry))
469 			return -ENOENT;
470 
471 		res = cifs_lookup(inode, direntry, 0);
472 		if (IS_ERR(res))
473 			return PTR_ERR(res);
474 
475 		return finish_no_open(file, res);
476 	}
477 
478 	xid = get_xid();
479 
480 	cifs_dbg(FYI, "parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
481 		 inode, direntry, direntry);
482 
483 	tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
484 	if (IS_ERR(tlink)) {
485 		rc = PTR_ERR(tlink);
486 		goto out_free_xid;
487 	}
488 
489 	tcon = tlink_tcon(tlink);
490 
491 	rc = check_name(direntry, tcon);
492 	if (rc)
493 		goto out;
494 
495 	server = tcon->ses->server;
496 
497 	if (server->ops->new_lease_key)
498 		server->ops->new_lease_key(&fid);
499 
500 	cifs_add_pending_open(&fid, tlink, &open);
501 
502 	rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,
503 			    &oplock, &fid, &buf);
504 	if (rc) {
505 		cifs_del_pending_open(&open);
506 		goto out;
507 	}
508 
509 	if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
510 		file->f_mode |= FMODE_CREATED;
511 
512 	rc = finish_open(file, direntry, generic_file_open);
513 	if (rc) {
514 		if (server->ops->close)
515 			server->ops->close(xid, tcon, &fid);
516 		cifs_del_pending_open(&open);
517 		goto out;
518 	}
519 
520 	if (file->f_flags & O_DIRECT &&
521 	    CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO) {
522 		if (CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
523 			file->f_op = &cifs_file_direct_nobrl_ops;
524 		else
525 			file->f_op = &cifs_file_direct_ops;
526 		}
527 
528 	file_info = cifs_new_fileinfo(&fid, file, tlink, oplock, buf.symlink_target);
529 	if (file_info == NULL) {
530 		if (server->ops->close)
531 			server->ops->close(xid, tcon, &fid);
532 		cifs_del_pending_open(&open);
533 		rc = -ENOMEM;
534 		goto out;
535 	}
536 
537 	fscache_use_cookie(cifs_inode_cookie(file_inode(file)),
538 			   file->f_mode & FMODE_WRITE);
539 
540 out:
541 	cifs_put_tlink(tlink);
542 out_free_xid:
543 	free_xid(xid);
544 	cifs_free_open_info(&buf);
545 	return rc;
546 }
547 
548 int cifs_create(struct mnt_idmap *idmap, struct inode *inode,
549 		struct dentry *direntry, umode_t mode, bool excl)
550 {
551 	int rc;
552 	unsigned int xid = get_xid();
553 	/*
554 	 * BB below access is probably too much for mknod to request
555 	 *    but we have to do query and setpathinfo so requesting
556 	 *    less could fail (unless we want to request getatr and setatr
557 	 *    permissions (only).  At least for POSIX we do not have to
558 	 *    request so much.
559 	 */
560 	unsigned oflags = O_EXCL | O_CREAT | O_RDWR;
561 	struct tcon_link *tlink;
562 	struct cifs_tcon *tcon;
563 	struct TCP_Server_Info *server;
564 	struct cifs_fid fid;
565 	__u32 oplock;
566 	struct cifs_open_info_data buf = {};
567 
568 	cifs_dbg(FYI, "cifs_create parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
569 		 inode, direntry, direntry);
570 
571 	if (unlikely(cifs_forced_shutdown(CIFS_SB(inode->i_sb)))) {
572 		rc = -EIO;
573 		goto out_free_xid;
574 	}
575 
576 	tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
577 	rc = PTR_ERR(tlink);
578 	if (IS_ERR(tlink))
579 		goto out_free_xid;
580 
581 	tcon = tlink_tcon(tlink);
582 	server = tcon->ses->server;
583 
584 	if (server->ops->new_lease_key)
585 		server->ops->new_lease_key(&fid);
586 
587 	rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode, &oplock, &fid, &buf);
588 	if (!rc && server->ops->close)
589 		server->ops->close(xid, tcon, &fid);
590 
591 	cifs_free_open_info(&buf);
592 	cifs_put_tlink(tlink);
593 out_free_xid:
594 	free_xid(xid);
595 	return rc;
596 }
597 
598 int cifs_mknod(struct mnt_idmap *idmap, struct inode *inode,
599 	       struct dentry *direntry, umode_t mode, dev_t device_number)
600 {
601 	int rc = -EPERM;
602 	unsigned int xid;
603 	struct cifs_sb_info *cifs_sb;
604 	struct tcon_link *tlink;
605 	struct cifs_tcon *tcon;
606 	const char *full_path;
607 	void *page;
608 
609 	if (!old_valid_dev(device_number))
610 		return -EINVAL;
611 
612 	cifs_sb = CIFS_SB(inode->i_sb);
613 	if (unlikely(cifs_forced_shutdown(cifs_sb)))
614 		return -EIO;
615 
616 	tlink = cifs_sb_tlink(cifs_sb);
617 	if (IS_ERR(tlink))
618 		return PTR_ERR(tlink);
619 
620 	page = alloc_dentry_path();
621 	tcon = tlink_tcon(tlink);
622 	xid = get_xid();
623 
624 	full_path = build_path_from_dentry(direntry, page);
625 	if (IS_ERR(full_path)) {
626 		rc = PTR_ERR(full_path);
627 		goto mknod_out;
628 	}
629 
630 	trace_smb3_mknod_enter(xid, tcon->ses->Suid, tcon->tid, full_path);
631 
632 	rc = tcon->ses->server->ops->make_node(xid, inode, direntry, tcon,
633 					       full_path, mode,
634 					       device_number);
635 
636 mknod_out:
637 	if (rc)
638 		trace_smb3_mknod_err(xid,  tcon->ses->Suid, tcon->tid, rc);
639 	else
640 		trace_smb3_mknod_done(xid, tcon->ses->Suid, tcon->tid);
641 
642 	free_dentry_path(page);
643 	free_xid(xid);
644 	cifs_put_tlink(tlink);
645 	return rc;
646 }
647 
648 struct dentry *
649 cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
650 	    unsigned int flags)
651 {
652 	unsigned int xid;
653 	int rc = 0; /* to get around spurious gcc warning, set to zero here */
654 	struct cifs_sb_info *cifs_sb;
655 	struct tcon_link *tlink;
656 	struct cifs_tcon *pTcon;
657 	struct inode *newInode = NULL;
658 	const char *full_path;
659 	void *page;
660 	int retry_count = 0;
661 
662 	xid = get_xid();
663 
664 	cifs_dbg(FYI, "parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
665 		 parent_dir_inode, direntry, direntry);
666 
667 	/* check whether path exists */
668 
669 	cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
670 	tlink = cifs_sb_tlink(cifs_sb);
671 	if (IS_ERR(tlink)) {
672 		free_xid(xid);
673 		return ERR_CAST(tlink);
674 	}
675 	pTcon = tlink_tcon(tlink);
676 
677 	rc = check_name(direntry, pTcon);
678 	if (unlikely(rc)) {
679 		cifs_put_tlink(tlink);
680 		free_xid(xid);
681 		return ERR_PTR(rc);
682 	}
683 
684 	/* can not grab the rename sem here since it would
685 	deadlock in the cases (beginning of sys_rename itself)
686 	in which we already have the sb rename sem */
687 	page = alloc_dentry_path();
688 	full_path = build_path_from_dentry(direntry, page);
689 	if (IS_ERR(full_path)) {
690 		cifs_put_tlink(tlink);
691 		free_xid(xid);
692 		free_dentry_path(page);
693 		return ERR_CAST(full_path);
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 again:
705 	if (pTcon->posix_extensions) {
706 		rc = smb311_posix_get_inode_info(&newInode, full_path, NULL,
707 						 parent_dir_inode->i_sb, xid);
708 	} else if (pTcon->unix_ext) {
709 		rc = cifs_get_inode_info_unix(&newInode, full_path,
710 					      parent_dir_inode->i_sb, xid);
711 	} else {
712 		rc = cifs_get_inode_info(&newInode, full_path, NULL,
713 				parent_dir_inode->i_sb, xid, NULL);
714 	}
715 
716 	if (rc == 0) {
717 		/* since paths are not looked up by component - the parent
718 		   directories are presumed to be good here */
719 		renew_parental_timestamps(direntry);
720 	} else if (rc == -EAGAIN && retry_count++ < 10) {
721 		goto again;
722 	} else if (rc == -ENOENT) {
723 		cifs_set_time(direntry, jiffies);
724 		newInode = NULL;
725 	} else {
726 		if (rc != -EACCES) {
727 			cifs_dbg(FYI, "Unexpected lookup error %d\n", rc);
728 			/* We special case check for Access Denied - since that
729 			is a common return code */
730 		}
731 		newInode = ERR_PTR(rc);
732 	}
733 	free_dentry_path(page);
734 	cifs_put_tlink(tlink);
735 	free_xid(xid);
736 	return d_splice_alias(newInode, direntry);
737 }
738 
739 static int
740 cifs_d_revalidate(struct dentry *direntry, unsigned int flags)
741 {
742 	struct inode *inode;
743 	int rc;
744 
745 	if (flags & LOOKUP_RCU)
746 		return -ECHILD;
747 
748 	if (d_really_is_positive(direntry)) {
749 		inode = d_inode(direntry);
750 		if ((flags & LOOKUP_REVAL) && !CIFS_CACHE_READ(CIFS_I(inode)))
751 			CIFS_I(inode)->time = 0; /* force reval */
752 
753 		rc = cifs_revalidate_dentry(direntry);
754 		if (rc) {
755 			cifs_dbg(FYI, "cifs_revalidate_dentry failed with rc=%d", rc);
756 			switch (rc) {
757 			case -ENOENT:
758 			case -ESTALE:
759 				/*
760 				 * Those errors mean the dentry is invalid
761 				 * (file was deleted or recreated)
762 				 */
763 				return 0;
764 			default:
765 				/*
766 				 * Otherwise some unexpected error happened
767 				 * report it as-is to VFS layer
768 				 */
769 				return rc;
770 			}
771 		}
772 		else {
773 			/*
774 			 * If the inode wasn't known to be a dfs entry when
775 			 * the dentry was instantiated, such as when created
776 			 * via ->readdir(), it needs to be set now since the
777 			 * attributes will have been updated by
778 			 * cifs_revalidate_dentry().
779 			 */
780 			if (IS_AUTOMOUNT(inode) &&
781 			   !(direntry->d_flags & DCACHE_NEED_AUTOMOUNT)) {
782 				spin_lock(&direntry->d_lock);
783 				direntry->d_flags |= DCACHE_NEED_AUTOMOUNT;
784 				spin_unlock(&direntry->d_lock);
785 			}
786 
787 			return 1;
788 		}
789 	}
790 
791 	/*
792 	 * This may be nfsd (or something), anyway, we can't see the
793 	 * intent of this. So, since this can be for creation, drop it.
794 	 */
795 	if (!flags)
796 		return 0;
797 
798 	/*
799 	 * Drop the negative dentry, in order to make sure to use the
800 	 * case sensitive name which is specified by user if this is
801 	 * for creation.
802 	 */
803 	if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
804 		return 0;
805 
806 	if (time_after(jiffies, cifs_get_time(direntry) + HZ) || !lookupCacheEnabled)
807 		return 0;
808 
809 	return 1;
810 }
811 
812 /* static int cifs_d_delete(struct dentry *direntry)
813 {
814 	int rc = 0;
815 
816 	cifs_dbg(FYI, "In cifs d_delete, name = %pd\n", direntry);
817 
818 	return rc;
819 }     */
820 
821 const struct dentry_operations cifs_dentry_ops = {
822 	.d_revalidate = cifs_d_revalidate,
823 	.d_automount = cifs_d_automount,
824 /* d_delete:       cifs_d_delete,      */ /* not needed except for debugging */
825 };
826 
827 static int cifs_ci_hash(const struct dentry *dentry, struct qstr *q)
828 {
829 	struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls;
830 	unsigned long hash;
831 	wchar_t c;
832 	int i, charlen;
833 
834 	hash = init_name_hash(dentry);
835 	for (i = 0; i < q->len; i += charlen) {
836 		charlen = codepage->char2uni(&q->name[i], q->len - i, &c);
837 		/* error out if we can't convert the character */
838 		if (unlikely(charlen < 0))
839 			return charlen;
840 		hash = partial_name_hash(cifs_toupper(c), hash);
841 	}
842 	q->hash = end_name_hash(hash);
843 
844 	return 0;
845 }
846 
847 static int cifs_ci_compare(const struct dentry *dentry,
848 		unsigned int len, const char *str, const struct qstr *name)
849 {
850 	struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls;
851 	wchar_t c1, c2;
852 	int i, l1, l2;
853 
854 	/*
855 	 * We make the assumption here that uppercase characters in the local
856 	 * codepage are always the same length as their lowercase counterparts.
857 	 *
858 	 * If that's ever not the case, then this will fail to match it.
859 	 */
860 	if (name->len != len)
861 		return 1;
862 
863 	for (i = 0; i < len; i += l1) {
864 		/* Convert characters in both strings to UTF-16. */
865 		l1 = codepage->char2uni(&str[i], len - i, &c1);
866 		l2 = codepage->char2uni(&name->name[i], name->len - i, &c2);
867 
868 		/*
869 		 * If we can't convert either character, just declare it to
870 		 * be 1 byte long and compare the original byte.
871 		 */
872 		if (unlikely(l1 < 0 && l2 < 0)) {
873 			if (str[i] != name->name[i])
874 				return 1;
875 			l1 = 1;
876 			continue;
877 		}
878 
879 		/*
880 		 * Here, we again ass|u|me that upper/lowercase versions of
881 		 * a character are the same length in the local NLS.
882 		 */
883 		if (l1 != l2)
884 			return 1;
885 
886 		/* Now compare uppercase versions of these characters */
887 		if (cifs_toupper(c1) != cifs_toupper(c2))
888 			return 1;
889 	}
890 
891 	return 0;
892 }
893 
894 const struct dentry_operations cifs_ci_dentry_ops = {
895 	.d_revalidate = cifs_d_revalidate,
896 	.d_hash = cifs_ci_hash,
897 	.d_compare = cifs_ci_compare,
898 	.d_automount = cifs_d_automount,
899 };
900