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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 		direntry->d_time = 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)49 cifs_build_path_to_root(struct smb_vol *vol, struct cifs_sb_info *cifs_sb,
50 			struct cifs_tcon *tcon)
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 (tcon->Flags & SMB_SHARE_IS_IN_DFS)
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 		strncpy(full_path, tcon->treeName, dfsplen);
73 	full_path[dfsplen] = CIFS_DIR_SEP(cifs_sb);
74 	strncpy(full_path + dfsplen + 1, vol->prepath, pplen);
75 	convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb));
76 	full_path[dfsplen + pplen] = 0; /* add trailing null */
77 	return full_path;
78 }
79 
80 /* Note: caller must free return buffer */
81 char *
build_path_from_dentry(struct dentry * direntry)82 build_path_from_dentry(struct dentry *direntry)
83 {
84 	struct dentry *temp;
85 	int namelen;
86 	int dfsplen;
87 	int pplen = 0;
88 	char *full_path;
89 	char dirsep;
90 	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
91 	struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
92 	unsigned seq;
93 
94 	dirsep = CIFS_DIR_SEP(cifs_sb);
95 	if (tcon->Flags & SMB_SHARE_IS_IN_DFS)
96 		dfsplen = strnlen(tcon->treeName, MAX_TREE_SIZE + 1);
97 	else
98 		dfsplen = 0;
99 
100 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH)
101 		pplen = cifs_sb->prepath ? strlen(cifs_sb->prepath) + 1 : 0;
102 
103 cifs_bp_rename_retry:
104 	namelen = dfsplen + pplen;
105 	seq = read_seqbegin(&rename_lock);
106 	rcu_read_lock();
107 	for (temp = direntry; !IS_ROOT(temp);) {
108 		namelen += (1 + temp->d_name.len);
109 		temp = temp->d_parent;
110 		if (temp == NULL) {
111 			cifs_dbg(VFS, "corrupt dentry\n");
112 			rcu_read_unlock();
113 			return NULL;
114 		}
115 	}
116 	rcu_read_unlock();
117 
118 	full_path = kmalloc(namelen+1, GFP_KERNEL);
119 	if (full_path == NULL)
120 		return full_path;
121 	full_path[namelen] = 0;	/* trailing null */
122 	rcu_read_lock();
123 	for (temp = direntry; !IS_ROOT(temp);) {
124 		spin_lock(&temp->d_lock);
125 		namelen -= 1 + temp->d_name.len;
126 		if (namelen < 0) {
127 			spin_unlock(&temp->d_lock);
128 			break;
129 		} else {
130 			full_path[namelen] = dirsep;
131 			strncpy(full_path + namelen + 1, temp->d_name.name,
132 				temp->d_name.len);
133 			cifs_dbg(FYI, "name: %s\n", full_path + namelen);
134 		}
135 		spin_unlock(&temp->d_lock);
136 		temp = temp->d_parent;
137 		if (temp == NULL) {
138 			cifs_dbg(VFS, "corrupt dentry\n");
139 			rcu_read_unlock();
140 			kfree(full_path);
141 			return NULL;
142 		}
143 	}
144 	rcu_read_unlock();
145 	if (namelen != dfsplen + pplen || read_seqretry(&rename_lock, seq)) {
146 		cifs_dbg(FYI, "did not end path lookup where expected. namelen=%ddfsplen=%d\n",
147 			 namelen, dfsplen);
148 		/* presumably this is only possible if racing with a rename
149 		of one of the parent directories  (we can not lock the dentries
150 		above us to prevent this, but retrying should be harmless) */
151 		kfree(full_path);
152 		goto cifs_bp_rename_retry;
153 	}
154 	/* DIR_SEP already set for byte  0 / vs \ but not for
155 	   subsequent slashes in prepath which currently must
156 	   be entered the right way - not sure if there is an alternative
157 	   since the '\' is a valid posix character so we can not switch
158 	   those safely to '/' if any are found in the middle of the prepath */
159 	/* BB test paths to Windows with '/' in the midst of prepath */
160 
161 	if (pplen) {
162 		int i;
163 
164 		cifs_dbg(FYI, "using cifs_sb prepath <%s>\n", cifs_sb->prepath);
165 		memcpy(full_path+dfsplen+1, cifs_sb->prepath, pplen-1);
166 		full_path[dfsplen] = dirsep;
167 		for (i = 0; i < pplen-1; i++)
168 			if (full_path[dfsplen+1+i] == '/')
169 				full_path[dfsplen+1+i] = CIFS_DIR_SEP(cifs_sb);
170 	}
171 
172 	if (dfsplen) {
173 		strncpy(full_path, tcon->treeName, dfsplen);
174 		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) {
175 			int i;
176 			for (i = 0; i < dfsplen; i++) {
177 				if (full_path[i] == '\\')
178 					full_path[i] = '/';
179 			}
180 		}
181 	}
182 	return full_path;
183 }
184 
185 /*
186  * Don't allow path components longer than the server max.
187  * Don't allow the separator character in a path component.
188  * The VFS will not allow "/", but "\" is allowed by posix.
189  */
190 static int
check_name(struct dentry * direntry,struct cifs_tcon * tcon)191 check_name(struct dentry *direntry, struct cifs_tcon *tcon)
192 {
193 	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
194 	int i;
195 
196 	if (unlikely(tcon->fsAttrInfo.MaxPathNameComponentLength &&
197 		     direntry->d_name.len >
198 		     le32_to_cpu(tcon->fsAttrInfo.MaxPathNameComponentLength)))
199 		return -ENAMETOOLONG;
200 
201 	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)) {
202 		for (i = 0; i < direntry->d_name.len; i++) {
203 			if (direntry->d_name.name[i] == '\\') {
204 				cifs_dbg(FYI, "Invalid file name\n");
205 				return -EINVAL;
206 			}
207 		}
208 	}
209 	return 0;
210 }
211 
212 
213 /* Inode operations in similar order to how they appear in Linux file fs.h */
214 
215 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)216 cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid,
217 	       struct tcon_link *tlink, unsigned oflags, umode_t mode,
218 	       __u32 *oplock, struct cifs_fid *fid)
219 {
220 	int rc = -ENOENT;
221 	int create_options = CREATE_NOT_DIR;
222 	int desired_access;
223 	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
224 	struct cifs_tcon *tcon = tlink_tcon(tlink);
225 	char *full_path = NULL;
226 	FILE_ALL_INFO *buf = NULL;
227 	struct inode *newinode = NULL;
228 	int disposition;
229 	struct TCP_Server_Info *server = tcon->ses->server;
230 	struct cifs_open_parms oparms;
231 
232 	*oplock = 0;
233 	if (tcon->ses->server->oplocks)
234 		*oplock = REQ_OPLOCK;
235 
236 	full_path = build_path_from_dentry(direntry);
237 	if (full_path == NULL) {
238 		rc = -ENOMEM;
239 		goto out;
240 	}
241 
242 	if (tcon->unix_ext && cap_unix(tcon->ses) && !tcon->broken_posix_open &&
243 	    (CIFS_UNIX_POSIX_PATH_OPS_CAP &
244 			le64_to_cpu(tcon->fsUnixInfo.Capability))) {
245 		rc = cifs_posix_open(full_path, &newinode, inode->i_sb, mode,
246 				     oflags, oplock, &fid->netfid, xid);
247 		switch (rc) {
248 		case 0:
249 			if (newinode == NULL) {
250 				/* query inode info */
251 				goto cifs_create_get_file_info;
252 			}
253 
254 			if (S_ISDIR(newinode->i_mode)) {
255 				CIFSSMBClose(xid, tcon, fid->netfid);
256 				iput(newinode);
257 				rc = -EISDIR;
258 				goto out;
259 			}
260 
261 			if (!S_ISREG(newinode->i_mode)) {
262 				/*
263 				 * The server may allow us to open things like
264 				 * FIFOs, but the client isn't set up to deal
265 				 * with that. If it's not a regular file, just
266 				 * close it and proceed as if it were a normal
267 				 * lookup.
268 				 */
269 				CIFSSMBClose(xid, tcon, fid->netfid);
270 				goto cifs_create_get_file_info;
271 			}
272 			/* success, no need to query */
273 			goto cifs_create_set_dentry;
274 
275 		case -ENOENT:
276 			goto cifs_create_get_file_info;
277 
278 		case -EIO:
279 		case -EINVAL:
280 			/*
281 			 * EIO could indicate that (posix open) operation is not
282 			 * supported, despite what server claimed in capability
283 			 * negotiation.
284 			 *
285 			 * POSIX open in samba versions 3.3.1 and earlier could
286 			 * incorrectly fail with invalid parameter.
287 			 */
288 			tcon->broken_posix_open = true;
289 			break;
290 
291 		case -EREMOTE:
292 		case -EOPNOTSUPP:
293 			/*
294 			 * EREMOTE indicates DFS junction, which is not handled
295 			 * in posix open.  If either that or op not supported
296 			 * returned, follow the normal lookup.
297 			 */
298 			break;
299 
300 		default:
301 			goto out;
302 		}
303 		/*
304 		 * fallthrough to retry, using older open call, this is case
305 		 * where server does not support this SMB level, and falsely
306 		 * claims capability (also get here for DFS case which should be
307 		 * rare for path not covered on files)
308 		 */
309 	}
310 
311 	desired_access = 0;
312 	if (OPEN_FMODE(oflags) & FMODE_READ)
313 		desired_access |= GENERIC_READ; /* is this too little? */
314 	if (OPEN_FMODE(oflags) & FMODE_WRITE)
315 		desired_access |= GENERIC_WRITE;
316 
317 	disposition = FILE_OVERWRITE_IF;
318 	if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
319 		disposition = FILE_CREATE;
320 	else if ((oflags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
321 		disposition = FILE_OVERWRITE_IF;
322 	else if ((oflags & O_CREAT) == O_CREAT)
323 		disposition = FILE_OPEN_IF;
324 	else
325 		cifs_dbg(FYI, "Create flag not set in create function\n");
326 
327 	/*
328 	 * BB add processing to set equivalent of mode - e.g. via CreateX with
329 	 * ACLs
330 	 */
331 
332 	if (!server->ops->open) {
333 		rc = -ENOSYS;
334 		goto out;
335 	}
336 
337 	buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
338 	if (buf == NULL) {
339 		rc = -ENOMEM;
340 		goto out;
341 	}
342 
343 	/*
344 	 * if we're not using unix extensions, see if we need to set
345 	 * ATTR_READONLY on the create call
346 	 */
347 	if (!tcon->unix_ext && (mode & S_IWUGO) == 0)
348 		create_options |= CREATE_OPTION_READONLY;
349 
350 	if (backup_cred(cifs_sb))
351 		create_options |= CREATE_OPEN_BACKUP_INTENT;
352 
353 	oparms.tcon = tcon;
354 	oparms.cifs_sb = cifs_sb;
355 	oparms.desired_access = desired_access;
356 	oparms.create_options = create_options;
357 	oparms.disposition = disposition;
358 	oparms.path = full_path;
359 	oparms.fid = fid;
360 	oparms.reconnect = false;
361 
362 	rc = server->ops->open(xid, &oparms, oplock, buf);
363 	if (rc) {
364 		cifs_dbg(FYI, "cifs_create returned 0x%x\n", rc);
365 		goto out;
366 	}
367 
368 	/*
369 	 * If Open reported that we actually created a file then we now have to
370 	 * set the mode if possible.
371 	 */
372 	if ((tcon->unix_ext) && (*oplock & CIFS_CREATE_ACTION)) {
373 		struct cifs_unix_set_info_args args = {
374 				.mode	= mode,
375 				.ctime	= NO_CHANGE_64,
376 				.atime	= NO_CHANGE_64,
377 				.mtime	= NO_CHANGE_64,
378 				.device	= 0,
379 		};
380 
381 		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
382 			args.uid = current_fsuid();
383 			if (inode->i_mode & S_ISGID)
384 				args.gid = inode->i_gid;
385 			else
386 				args.gid = current_fsgid();
387 		} else {
388 			args.uid = INVALID_UID; /* no change */
389 			args.gid = INVALID_GID; /* no change */
390 		}
391 		CIFSSMBUnixSetFileInfo(xid, tcon, &args, fid->netfid,
392 				       current->tgid);
393 	} else {
394 		/*
395 		 * BB implement mode setting via Windows security
396 		 * descriptors e.g.
397 		 */
398 		/* CIFSSMBWinSetPerms(xid,tcon,path,mode,-1,-1,nls);*/
399 
400 		/* Could set r/o dos attribute if mode & 0222 == 0 */
401 	}
402 
403 cifs_create_get_file_info:
404 	/* server might mask mode so we have to query for it */
405 	if (tcon->unix_ext)
406 		rc = cifs_get_inode_info_unix(&newinode, full_path, inode->i_sb,
407 					      xid);
408 	else {
409 		rc = cifs_get_inode_info(&newinode, full_path, buf, inode->i_sb,
410 					 xid, fid);
411 		if (newinode) {
412 			if (server->ops->set_lease_key)
413 				server->ops->set_lease_key(newinode, fid);
414 			if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM)
415 				newinode->i_mode = mode;
416 			if ((*oplock & CIFS_CREATE_ACTION) &&
417 			    (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID)) {
418 				newinode->i_uid = current_fsuid();
419 				if (inode->i_mode & S_ISGID)
420 					newinode->i_gid = inode->i_gid;
421 				else
422 					newinode->i_gid = current_fsgid();
423 			}
424 		}
425 	}
426 
427 cifs_create_set_dentry:
428 	if (rc != 0) {
429 		cifs_dbg(FYI, "Create worked, get_inode_info failed rc = %d\n",
430 			 rc);
431 		goto out_err;
432 	}
433 
434 	if (S_ISDIR(newinode->i_mode)) {
435 		rc = -EISDIR;
436 		goto out_err;
437 	}
438 
439 	d_drop(direntry);
440 	d_add(direntry, newinode);
441 
442 out:
443 	kfree(buf);
444 	kfree(full_path);
445 	return rc;
446 
447 out_err:
448 	if (server->ops->close)
449 		server->ops->close(xid, tcon, fid);
450 	if (newinode)
451 		iput(newinode);
452 	goto out;
453 }
454 
455 int
cifs_atomic_open(struct inode * inode,struct dentry * direntry,struct file * file,unsigned oflags,umode_t mode,int * opened)456 cifs_atomic_open(struct inode *inode, struct dentry *direntry,
457 		 struct file *file, unsigned oflags, umode_t mode,
458 		 int *opened)
459 {
460 	int rc;
461 	unsigned int xid;
462 	struct tcon_link *tlink;
463 	struct cifs_tcon *tcon;
464 	struct TCP_Server_Info *server;
465 	struct cifs_fid fid;
466 	struct cifs_pending_open open;
467 	__u32 oplock;
468 	struct cifsFileInfo *file_info;
469 
470 	/*
471 	 * Posix open is only called (at lookup time) for file create now. For
472 	 * opens (rather than creates), because we do not know if it is a file
473 	 * or directory yet, and current Samba no longer allows us to do posix
474 	 * open on dirs, we could end up wasting an open call on what turns out
475 	 * to be a dir. For file opens, we wait to call posix open till
476 	 * cifs_open.  It could be added to atomic_open in the future but the
477 	 * performance tradeoff of the extra network request when EISDIR or
478 	 * EACCES is returned would have to be weighed against the 50% reduction
479 	 * in network traffic in the other paths.
480 	 */
481 	if (!(oflags & O_CREAT)) {
482 		struct dentry *res;
483 
484 		/*
485 		 * Check for hashed negative dentry. We have already revalidated
486 		 * the dentry and it is fine. No need to perform another lookup.
487 		 */
488 		if (!d_unhashed(direntry))
489 			return -ENOENT;
490 
491 		res = cifs_lookup(inode, direntry, 0);
492 		if (IS_ERR(res))
493 			return PTR_ERR(res);
494 
495 		return finish_no_open(file, res);
496 	}
497 
498 	xid = get_xid();
499 
500 	cifs_dbg(FYI, "parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
501 		 inode, direntry, direntry);
502 
503 	tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
504 	if (IS_ERR(tlink)) {
505 		rc = PTR_ERR(tlink);
506 		goto out_free_xid;
507 	}
508 
509 	tcon = tlink_tcon(tlink);
510 
511 	rc = check_name(direntry, tcon);
512 	if (rc)
513 		goto out;
514 
515 	server = tcon->ses->server;
516 
517 	if (server->ops->new_lease_key)
518 		server->ops->new_lease_key(&fid);
519 
520 	cifs_add_pending_open(&fid, tlink, &open);
521 
522 	rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,
523 			    &oplock, &fid);
524 
525 	if (rc) {
526 		cifs_del_pending_open(&open);
527 		goto out;
528 	}
529 
530 	if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
531 		*opened |= FILE_CREATED;
532 
533 	rc = finish_open(file, direntry, generic_file_open, opened);
534 	if (rc) {
535 		if (server->ops->close)
536 			server->ops->close(xid, tcon, &fid);
537 		cifs_del_pending_open(&open);
538 		goto out;
539 	}
540 
541 	if (file->f_flags & O_DIRECT &&
542 	    CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO) {
543 		if (CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
544 			file->f_op = &cifs_file_direct_nobrl_ops;
545 		else
546 			file->f_op = &cifs_file_direct_ops;
547 		}
548 
549 	file_info = cifs_new_fileinfo(&fid, file, tlink, oplock);
550 	if (file_info == NULL) {
551 		if (server->ops->close)
552 			server->ops->close(xid, tcon, &fid);
553 		cifs_del_pending_open(&open);
554 		fput(file);
555 		rc = -ENOMEM;
556 	}
557 
558 out:
559 	cifs_put_tlink(tlink);
560 out_free_xid:
561 	free_xid(xid);
562 	return rc;
563 }
564 
cifs_create(struct inode * inode,struct dentry * direntry,umode_t mode,bool excl)565 int cifs_create(struct inode *inode, struct dentry *direntry, umode_t mode,
566 		bool excl)
567 {
568 	int rc;
569 	unsigned int xid = get_xid();
570 	/*
571 	 * BB below access is probably too much for mknod to request
572 	 *    but we have to do query and setpathinfo so requesting
573 	 *    less could fail (unless we want to request getatr and setatr
574 	 *    permissions (only).  At least for POSIX we do not have to
575 	 *    request so much.
576 	 */
577 	unsigned oflags = O_EXCL | O_CREAT | O_RDWR;
578 	struct tcon_link *tlink;
579 	struct cifs_tcon *tcon;
580 	struct TCP_Server_Info *server;
581 	struct cifs_fid fid;
582 	__u32 oplock;
583 
584 	cifs_dbg(FYI, "cifs_create parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
585 		 inode, direntry, direntry);
586 
587 	tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
588 	rc = PTR_ERR(tlink);
589 	if (IS_ERR(tlink))
590 		goto out_free_xid;
591 
592 	tcon = tlink_tcon(tlink);
593 	server = tcon->ses->server;
594 
595 	if (server->ops->new_lease_key)
596 		server->ops->new_lease_key(&fid);
597 
598 	rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,
599 			    &oplock, &fid);
600 	if (!rc && server->ops->close)
601 		server->ops->close(xid, tcon, &fid);
602 
603 	cifs_put_tlink(tlink);
604 out_free_xid:
605 	free_xid(xid);
606 	return rc;
607 }
608 
cifs_mknod(struct inode * inode,struct dentry * direntry,umode_t mode,dev_t device_number)609 int cifs_mknod(struct inode *inode, struct dentry *direntry, umode_t mode,
610 		dev_t device_number)
611 {
612 	int rc = -EPERM;
613 	unsigned int xid;
614 	int create_options = CREATE_NOT_DIR | CREATE_OPTION_SPECIAL;
615 	struct cifs_sb_info *cifs_sb;
616 	struct tcon_link *tlink;
617 	struct cifs_tcon *tcon;
618 	struct cifs_io_parms io_parms;
619 	char *full_path = NULL;
620 	struct inode *newinode = NULL;
621 	__u32 oplock = 0;
622 	struct cifs_fid fid;
623 	struct cifs_open_parms oparms;
624 	FILE_ALL_INFO *buf = NULL;
625 	unsigned int bytes_written;
626 	struct win_dev *pdev;
627 	struct kvec iov[2];
628 
629 	if (!old_valid_dev(device_number))
630 		return -EINVAL;
631 
632 	cifs_sb = CIFS_SB(inode->i_sb);
633 	tlink = cifs_sb_tlink(cifs_sb);
634 	if (IS_ERR(tlink))
635 		return PTR_ERR(tlink);
636 
637 	tcon = tlink_tcon(tlink);
638 
639 	xid = get_xid();
640 
641 	full_path = build_path_from_dentry(direntry);
642 	if (full_path == NULL) {
643 		rc = -ENOMEM;
644 		goto mknod_out;
645 	}
646 
647 	if (tcon->unix_ext) {
648 		struct cifs_unix_set_info_args args = {
649 			.mode	= mode & ~current_umask(),
650 			.ctime	= NO_CHANGE_64,
651 			.atime	= NO_CHANGE_64,
652 			.mtime	= NO_CHANGE_64,
653 			.device	= device_number,
654 		};
655 		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
656 			args.uid = current_fsuid();
657 			args.gid = current_fsgid();
658 		} else {
659 			args.uid = INVALID_UID; /* no change */
660 			args.gid = INVALID_GID; /* no change */
661 		}
662 		rc = CIFSSMBUnixSetPathInfo(xid, tcon, full_path, &args,
663 					    cifs_sb->local_nls,
664 					    cifs_remap(cifs_sb));
665 		if (rc)
666 			goto mknod_out;
667 
668 		rc = cifs_get_inode_info_unix(&newinode, full_path,
669 						inode->i_sb, xid);
670 
671 		if (rc == 0)
672 			d_instantiate(direntry, newinode);
673 		goto mknod_out;
674 	}
675 
676 	if (!S_ISCHR(mode) && !S_ISBLK(mode))
677 		goto mknod_out;
678 
679 	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL))
680 		goto mknod_out;
681 
682 
683 	cifs_dbg(FYI, "sfu compat create special file\n");
684 
685 	buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
686 	if (buf == NULL) {
687 		rc = -ENOMEM;
688 		goto mknod_out;
689 	}
690 
691 	if (backup_cred(cifs_sb))
692 		create_options |= CREATE_OPEN_BACKUP_INTENT;
693 
694 	oparms.tcon = tcon;
695 	oparms.cifs_sb = cifs_sb;
696 	oparms.desired_access = GENERIC_WRITE;
697 	oparms.create_options = create_options;
698 	oparms.disposition = FILE_CREATE;
699 	oparms.path = full_path;
700 	oparms.fid = &fid;
701 	oparms.reconnect = false;
702 
703 	if (tcon->ses->server->oplocks)
704 		oplock = REQ_OPLOCK;
705 	else
706 		oplock = 0;
707 	rc = tcon->ses->server->ops->open(xid, &oparms, &oplock, buf);
708 	if (rc)
709 		goto mknod_out;
710 
711 	/*
712 	 * BB Do not bother to decode buf since no local inode yet to put
713 	 * timestamps in, but we can reuse it safely.
714 	 */
715 
716 	pdev = (struct win_dev *)buf;
717 	io_parms.pid = current->tgid;
718 	io_parms.tcon = tcon;
719 	io_parms.offset = 0;
720 	io_parms.length = sizeof(struct win_dev);
721 	iov[1].iov_base = buf;
722 	iov[1].iov_len = sizeof(struct win_dev);
723 	if (S_ISCHR(mode)) {
724 		memcpy(pdev->type, "IntxCHR", 8);
725 		pdev->major = cpu_to_le64(MAJOR(device_number));
726 		pdev->minor = cpu_to_le64(MINOR(device_number));
727 		rc = tcon->ses->server->ops->sync_write(xid, &fid, &io_parms,
728 							&bytes_written, iov, 1);
729 	} else if (S_ISBLK(mode)) {
730 		memcpy(pdev->type, "IntxBLK", 8);
731 		pdev->major = cpu_to_le64(MAJOR(device_number));
732 		pdev->minor = cpu_to_le64(MINOR(device_number));
733 		rc = tcon->ses->server->ops->sync_write(xid, &fid, &io_parms,
734 							&bytes_written, iov, 1);
735 	}
736 	tcon->ses->server->ops->close(xid, tcon, &fid);
737 	d_drop(direntry);
738 
739 	/* FIXME: add code here to set EAs */
740 
741 mknod_out:
742 	kfree(full_path);
743 	kfree(buf);
744 	free_xid(xid);
745 	cifs_put_tlink(tlink);
746 	return rc;
747 }
748 
749 struct dentry *
cifs_lookup(struct inode * parent_dir_inode,struct dentry * direntry,unsigned int flags)750 cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
751 	    unsigned int flags)
752 {
753 	unsigned int xid;
754 	int rc = 0; /* to get around spurious gcc warning, set to zero here */
755 	struct cifs_sb_info *cifs_sb;
756 	struct tcon_link *tlink;
757 	struct cifs_tcon *pTcon;
758 	struct inode *newInode = NULL;
759 	char *full_path = NULL;
760 
761 	xid = get_xid();
762 
763 	cifs_dbg(FYI, "parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
764 		 parent_dir_inode, direntry, direntry);
765 
766 	/* check whether path exists */
767 
768 	cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
769 	tlink = cifs_sb_tlink(cifs_sb);
770 	if (IS_ERR(tlink)) {
771 		free_xid(xid);
772 		return (struct dentry *)tlink;
773 	}
774 	pTcon = tlink_tcon(tlink);
775 
776 	rc = check_name(direntry, pTcon);
777 	if (rc)
778 		goto lookup_out;
779 
780 	/* can not grab the rename sem here since it would
781 	deadlock in the cases (beginning of sys_rename itself)
782 	in which we already have the sb rename sem */
783 	full_path = build_path_from_dentry(direntry);
784 	if (full_path == NULL) {
785 		rc = -ENOMEM;
786 		goto lookup_out;
787 	}
788 
789 	if (d_really_is_positive(direntry)) {
790 		cifs_dbg(FYI, "non-NULL inode in lookup\n");
791 	} else {
792 		cifs_dbg(FYI, "NULL inode in lookup\n");
793 	}
794 	cifs_dbg(FYI, "Full path: %s inode = 0x%p\n",
795 		 full_path, d_inode(direntry));
796 
797 	if (pTcon->unix_ext) {
798 		rc = cifs_get_inode_info_unix(&newInode, full_path,
799 					      parent_dir_inode->i_sb, xid);
800 	} else {
801 		rc = cifs_get_inode_info(&newInode, full_path, NULL,
802 				parent_dir_inode->i_sb, xid, NULL);
803 	}
804 
805 	if ((rc == 0) && (newInode != NULL)) {
806 		d_add(direntry, newInode);
807 		/* since paths are not looked up by component - the parent
808 		   directories are presumed to be good here */
809 		renew_parental_timestamps(direntry);
810 
811 	} else if (rc == -ENOENT) {
812 		rc = 0;
813 		direntry->d_time = jiffies;
814 		d_add(direntry, NULL);
815 	/*	if it was once a directory (but how can we tell?) we could do
816 		shrink_dcache_parent(direntry); */
817 	} else if (rc != -EACCES) {
818 		cifs_dbg(FYI, "Unexpected lookup error %d\n", rc);
819 		/* We special case check for Access Denied - since that
820 		is a common return code */
821 	}
822 
823 lookup_out:
824 	kfree(full_path);
825 	cifs_put_tlink(tlink);
826 	free_xid(xid);
827 	return ERR_PTR(rc);
828 }
829 
830 static int
cifs_d_revalidate(struct dentry * direntry,unsigned int flags)831 cifs_d_revalidate(struct dentry *direntry, unsigned int flags)
832 {
833 	struct inode *inode;
834 	int rc;
835 
836 	if (flags & LOOKUP_RCU)
837 		return -ECHILD;
838 
839 	if (d_really_is_positive(direntry)) {
840 		inode = d_inode(direntry);
841 		if ((flags & LOOKUP_REVAL) && !CIFS_CACHE_READ(CIFS_I(inode)))
842 			CIFS_I(inode)->time = 0; /* force reval */
843 
844 		rc = cifs_revalidate_dentry(direntry);
845 		if (rc) {
846 			cifs_dbg(FYI, "cifs_revalidate_dentry failed with rc=%d", rc);
847 			switch (rc) {
848 			case -ENOENT:
849 			case -ESTALE:
850 				/*
851 				 * Those errors mean the dentry is invalid
852 				 * (file was deleted or recreated)
853 				 */
854 				return 0;
855 			default:
856 				/*
857 				 * Otherwise some unexpected error happened
858 				 * report it as-is to VFS layer
859 				 */
860 				return rc;
861 			}
862 		}
863 		else {
864 			/*
865 			 * If the inode wasn't known to be a dfs entry when
866 			 * the dentry was instantiated, such as when created
867 			 * via ->readdir(), it needs to be set now since the
868 			 * attributes will have been updated by
869 			 * cifs_revalidate_dentry().
870 			 */
871 			if (IS_AUTOMOUNT(inode) &&
872 			   !(direntry->d_flags & DCACHE_NEED_AUTOMOUNT)) {
873 				spin_lock(&direntry->d_lock);
874 				direntry->d_flags |= DCACHE_NEED_AUTOMOUNT;
875 				spin_unlock(&direntry->d_lock);
876 			}
877 
878 			return 1;
879 		}
880 	}
881 
882 	/*
883 	 * This may be nfsd (or something), anyway, we can't see the
884 	 * intent of this. So, since this can be for creation, drop it.
885 	 */
886 	if (!flags)
887 		return 0;
888 
889 	/*
890 	 * Drop the negative dentry, in order to make sure to use the
891 	 * case sensitive name which is specified by user if this is
892 	 * for creation.
893 	 */
894 	if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
895 		return 0;
896 
897 	if (time_after(jiffies, direntry->d_time + HZ) || !lookupCacheEnabled)
898 		return 0;
899 
900 	return 1;
901 }
902 
903 /* static int cifs_d_delete(struct dentry *direntry)
904 {
905 	int rc = 0;
906 
907 	cifs_dbg(FYI, "In cifs d_delete, name = %pd\n", direntry);
908 
909 	return rc;
910 }     */
911 
912 const struct dentry_operations cifs_dentry_ops = {
913 	.d_revalidate = cifs_d_revalidate,
914 	.d_automount = cifs_dfs_d_automount,
915 /* d_delete:       cifs_d_delete,      */ /* not needed except for debugging */
916 };
917 
cifs_ci_hash(const struct dentry * dentry,struct qstr * q)918 static int cifs_ci_hash(const struct dentry *dentry, struct qstr *q)
919 {
920 	struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls;
921 	unsigned long hash;
922 	wchar_t c;
923 	int i, charlen;
924 
925 	hash = init_name_hash();
926 	for (i = 0; i < q->len; i += charlen) {
927 		charlen = codepage->char2uni(&q->name[i], q->len - i, &c);
928 		/* error out if we can't convert the character */
929 		if (unlikely(charlen < 0))
930 			return charlen;
931 		hash = partial_name_hash(cifs_toupper(c), hash);
932 	}
933 	q->hash = end_name_hash(hash);
934 
935 	return 0;
936 }
937 
cifs_ci_compare(const struct dentry * parent,const struct dentry * dentry,unsigned int len,const char * str,const struct qstr * name)938 static int cifs_ci_compare(const struct dentry *parent, const struct dentry *dentry,
939 		unsigned int len, const char *str, const struct qstr *name)
940 {
941 	struct nls_table *codepage = CIFS_SB(parent->d_sb)->local_nls;
942 	wchar_t c1, c2;
943 	int i, l1, l2;
944 
945 	/*
946 	 * We make the assumption here that uppercase characters in the local
947 	 * codepage are always the same length as their lowercase counterparts.
948 	 *
949 	 * If that's ever not the case, then this will fail to match it.
950 	 */
951 	if (name->len != len)
952 		return 1;
953 
954 	for (i = 0; i < len; i += l1) {
955 		/* Convert characters in both strings to UTF-16. */
956 		l1 = codepage->char2uni(&str[i], len - i, &c1);
957 		l2 = codepage->char2uni(&name->name[i], name->len - i, &c2);
958 
959 		/*
960 		 * If we can't convert either character, just declare it to
961 		 * be 1 byte long and compare the original byte.
962 		 */
963 		if (unlikely(l1 < 0 && l2 < 0)) {
964 			if (str[i] != name->name[i])
965 				return 1;
966 			l1 = 1;
967 			continue;
968 		}
969 
970 		/*
971 		 * Here, we again ass|u|me that upper/lowercase versions of
972 		 * a character are the same length in the local NLS.
973 		 */
974 		if (l1 != l2)
975 			return 1;
976 
977 		/* Now compare uppercase versions of these characters */
978 		if (cifs_toupper(c1) != cifs_toupper(c2))
979 			return 1;
980 	}
981 
982 	return 0;
983 }
984 
985 const struct dentry_operations cifs_ci_dentry_ops = {
986 	.d_revalidate = cifs_d_revalidate,
987 	.d_hash = cifs_ci_hash,
988 	.d_compare = cifs_ci_compare,
989 	.d_automount = cifs_dfs_d_automount,
990 };
991