• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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