Merge tag 'atlas7-pinctrl-dts-for-4.2' of git://git.kernel.org/pub/scm/linux/kernel...
[firefly-linux-kernel-4.4.55.git] / fs / cifs / dir.c
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
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 *
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 *
82 build_path_from_dentry(struct dentry *direntry)
83 {
84         struct dentry *temp;
85         int namelen;
86         int dfsplen;
87         char *full_path;
88         char dirsep;
89         struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
90         struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
91         unsigned seq;
92
93         dirsep = CIFS_DIR_SEP(cifs_sb);
94         if (tcon->Flags & SMB_SHARE_IS_IN_DFS)
95                 dfsplen = strnlen(tcon->treeName, MAX_TREE_SIZE + 1);
96         else
97                 dfsplen = 0;
98 cifs_bp_rename_retry:
99         namelen = dfsplen;
100         seq = read_seqbegin(&rename_lock);
101         rcu_read_lock();
102         for (temp = direntry; !IS_ROOT(temp);) {
103                 namelen += (1 + temp->d_name.len);
104                 temp = temp->d_parent;
105                 if (temp == NULL) {
106                         cifs_dbg(VFS, "corrupt dentry\n");
107                         rcu_read_unlock();
108                         return NULL;
109                 }
110         }
111         rcu_read_unlock();
112
113         full_path = kmalloc(namelen+1, GFP_KERNEL);
114         if (full_path == NULL)
115                 return full_path;
116         full_path[namelen] = 0; /* trailing null */
117         rcu_read_lock();
118         for (temp = direntry; !IS_ROOT(temp);) {
119                 spin_lock(&temp->d_lock);
120                 namelen -= 1 + temp->d_name.len;
121                 if (namelen < 0) {
122                         spin_unlock(&temp->d_lock);
123                         break;
124                 } else {
125                         full_path[namelen] = dirsep;
126                         strncpy(full_path + namelen + 1, temp->d_name.name,
127                                 temp->d_name.len);
128                         cifs_dbg(FYI, "name: %s\n", full_path + namelen);
129                 }
130                 spin_unlock(&temp->d_lock);
131                 temp = temp->d_parent;
132                 if (temp == NULL) {
133                         cifs_dbg(VFS, "corrupt dentry\n");
134                         rcu_read_unlock();
135                         kfree(full_path);
136                         return NULL;
137                 }
138         }
139         rcu_read_unlock();
140         if (namelen != dfsplen || read_seqretry(&rename_lock, seq)) {
141                 cifs_dbg(FYI, "did not end path lookup where expected. namelen=%ddfsplen=%d\n",
142                          namelen, dfsplen);
143                 /* presumably this is only possible if racing with a rename
144                 of one of the parent directories  (we can not lock the dentries
145                 above us to prevent this, but retrying should be harmless) */
146                 kfree(full_path);
147                 goto cifs_bp_rename_retry;
148         }
149         /* DIR_SEP already set for byte  0 / vs \ but not for
150            subsequent slashes in prepath which currently must
151            be entered the right way - not sure if there is an alternative
152            since the '\' is a valid posix character so we can not switch
153            those safely to '/' if any are found in the middle of the prepath */
154         /* BB test paths to Windows with '/' in the midst of prepath */
155
156         if (dfsplen) {
157                 strncpy(full_path, tcon->treeName, dfsplen);
158                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) {
159                         int i;
160                         for (i = 0; i < dfsplen; i++) {
161                                 if (full_path[i] == '\\')
162                                         full_path[i] = '/';
163                         }
164                 }
165         }
166         return full_path;
167 }
168
169 /*
170  * Don't allow the separator character in a path component.
171  * The VFS will not allow "/", but "\" is allowed by posix.
172  */
173 static int
174 check_name(struct dentry *direntry)
175 {
176         struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
177         int i;
178
179         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)) {
180                 for (i = 0; i < direntry->d_name.len; i++) {
181                         if (direntry->d_name.name[i] == '\\') {
182                                 cifs_dbg(FYI, "Invalid file name\n");
183                                 return -EINVAL;
184                         }
185                 }
186         }
187         return 0;
188 }
189
190
191 /* Inode operations in similar order to how they appear in Linux file fs.h */
192
193 static int
194 cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid,
195                struct tcon_link *tlink, unsigned oflags, umode_t mode,
196                __u32 *oplock, struct cifs_fid *fid)
197 {
198         int rc = -ENOENT;
199         int create_options = CREATE_NOT_DIR;
200         int desired_access;
201         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
202         struct cifs_tcon *tcon = tlink_tcon(tlink);
203         char *full_path = NULL;
204         FILE_ALL_INFO *buf = NULL;
205         struct inode *newinode = NULL;
206         int disposition;
207         struct TCP_Server_Info *server = tcon->ses->server;
208         struct cifs_open_parms oparms;
209
210         *oplock = 0;
211         if (tcon->ses->server->oplocks)
212                 *oplock = REQ_OPLOCK;
213
214         full_path = build_path_from_dentry(direntry);
215         if (full_path == NULL) {
216                 rc = -ENOMEM;
217                 goto out;
218         }
219
220         if (tcon->unix_ext && cap_unix(tcon->ses) && !tcon->broken_posix_open &&
221             (CIFS_UNIX_POSIX_PATH_OPS_CAP &
222                         le64_to_cpu(tcon->fsUnixInfo.Capability))) {
223                 rc = cifs_posix_open(full_path, &newinode, inode->i_sb, mode,
224                                      oflags, oplock, &fid->netfid, xid);
225                 switch (rc) {
226                 case 0:
227                         if (newinode == NULL) {
228                                 /* query inode info */
229                                 goto cifs_create_get_file_info;
230                         }
231
232                         if (!S_ISREG(newinode->i_mode)) {
233                                 /*
234                                  * The server may allow us to open things like
235                                  * FIFOs, but the client isn't set up to deal
236                                  * with that. If it's not a regular file, just
237                                  * close it and proceed as if it were a normal
238                                  * lookup.
239                                  */
240                                 CIFSSMBClose(xid, tcon, fid->netfid);
241                                 goto cifs_create_get_file_info;
242                         }
243                         /* success, no need to query */
244                         goto cifs_create_set_dentry;
245
246                 case -ENOENT:
247                         goto cifs_create_get_file_info;
248
249                 case -EIO:
250                 case -EINVAL:
251                         /*
252                          * EIO could indicate that (posix open) operation is not
253                          * supported, despite what server claimed in capability
254                          * negotiation.
255                          *
256                          * POSIX open in samba versions 3.3.1 and earlier could
257                          * incorrectly fail with invalid parameter.
258                          */
259                         tcon->broken_posix_open = true;
260                         break;
261
262                 case -EREMOTE:
263                 case -EOPNOTSUPP:
264                         /*
265                          * EREMOTE indicates DFS junction, which is not handled
266                          * in posix open.  If either that or op not supported
267                          * returned, follow the normal lookup.
268                          */
269                         break;
270
271                 default:
272                         goto out;
273                 }
274                 /*
275                  * fallthrough to retry, using older open call, this is case
276                  * where server does not support this SMB level, and falsely
277                  * claims capability (also get here for DFS case which should be
278                  * rare for path not covered on files)
279                  */
280         }
281
282         desired_access = 0;
283         if (OPEN_FMODE(oflags) & FMODE_READ)
284                 desired_access |= GENERIC_READ; /* is this too little? */
285         if (OPEN_FMODE(oflags) & FMODE_WRITE)
286                 desired_access |= GENERIC_WRITE;
287
288         disposition = FILE_OVERWRITE_IF;
289         if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
290                 disposition = FILE_CREATE;
291         else if ((oflags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
292                 disposition = FILE_OVERWRITE_IF;
293         else if ((oflags & O_CREAT) == O_CREAT)
294                 disposition = FILE_OPEN_IF;
295         else
296                 cifs_dbg(FYI, "Create flag not set in create function\n");
297
298         /*
299          * BB add processing to set equivalent of mode - e.g. via CreateX with
300          * ACLs
301          */
302
303         if (!server->ops->open) {
304                 rc = -ENOSYS;
305                 goto out;
306         }
307
308         buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
309         if (buf == NULL) {
310                 rc = -ENOMEM;
311                 goto out;
312         }
313
314         /*
315          * if we're not using unix extensions, see if we need to set
316          * ATTR_READONLY on the create call
317          */
318         if (!tcon->unix_ext && (mode & S_IWUGO) == 0)
319                 create_options |= CREATE_OPTION_READONLY;
320
321         if (backup_cred(cifs_sb))
322                 create_options |= CREATE_OPEN_BACKUP_INTENT;
323
324         oparms.tcon = tcon;
325         oparms.cifs_sb = cifs_sb;
326         oparms.desired_access = desired_access;
327         oparms.create_options = create_options;
328         oparms.disposition = disposition;
329         oparms.path = full_path;
330         oparms.fid = fid;
331         oparms.reconnect = false;
332
333         rc = server->ops->open(xid, &oparms, oplock, buf);
334         if (rc) {
335                 cifs_dbg(FYI, "cifs_create returned 0x%x\n", rc);
336                 goto out;
337         }
338
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                 rc = cifs_get_inode_info(&newinode, full_path, buf, inode->i_sb,
381                                          xid, fid);
382                 if (newinode) {
383                         if (server->ops->set_lease_key)
384                                 server->ops->set_lease_key(newinode, fid);
385                         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM)
386                                 newinode->i_mode = mode;
387                         if ((*oplock & CIFS_CREATE_ACTION) &&
388                             (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID)) {
389                                 newinode->i_uid = current_fsuid();
390                                 if (inode->i_mode & S_ISGID)
391                                         newinode->i_gid = inode->i_gid;
392                                 else
393                                         newinode->i_gid = current_fsgid();
394                         }
395                 }
396         }
397
398 cifs_create_set_dentry:
399         if (rc != 0) {
400                 cifs_dbg(FYI, "Create worked, get_inode_info failed rc = %d\n",
401                          rc);
402                 if (server->ops->close)
403                         server->ops->close(xid, tcon, fid);
404                 goto out;
405         }
406         d_drop(direntry);
407         d_add(direntry, newinode);
408
409 out:
410         kfree(buf);
411         kfree(full_path);
412         return rc;
413 }
414
415 int
416 cifs_atomic_open(struct inode *inode, struct dentry *direntry,
417                  struct file *file, unsigned oflags, umode_t mode,
418                  int *opened)
419 {
420         int rc;
421         unsigned int xid;
422         struct tcon_link *tlink;
423         struct cifs_tcon *tcon;
424         struct TCP_Server_Info *server;
425         struct cifs_fid fid;
426         struct cifs_pending_open open;
427         __u32 oplock;
428         struct cifsFileInfo *file_info;
429
430         /*
431          * Posix open is only called (at lookup time) for file create now. For
432          * opens (rather than creates), because we do not know if it is a file
433          * or directory yet, and current Samba no longer allows us to do posix
434          * open on dirs, we could end up wasting an open call on what turns out
435          * to be a dir. For file opens, we wait to call posix open till
436          * cifs_open.  It could be added to atomic_open in the future but the
437          * performance tradeoff of the extra network request when EISDIR or
438          * EACCES is returned would have to be weighed against the 50% reduction
439          * in network traffic in the other paths.
440          */
441         if (!(oflags & O_CREAT)) {
442                 struct dentry *res;
443
444                 /*
445                  * Check for hashed negative dentry. We have already revalidated
446                  * the dentry and it is fine. No need to perform another lookup.
447                  */
448                 if (!d_unhashed(direntry))
449                         return -ENOENT;
450
451                 res = cifs_lookup(inode, direntry, 0);
452                 if (IS_ERR(res))
453                         return PTR_ERR(res);
454
455                 return finish_no_open(file, res);
456         }
457
458         rc = check_name(direntry);
459         if (rc)
460                 return rc;
461
462         xid = get_xid();
463
464         cifs_dbg(FYI, "parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
465                  inode, direntry, direntry);
466
467         tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
468         if (IS_ERR(tlink)) {
469                 rc = PTR_ERR(tlink);
470                 goto out_free_xid;
471         }
472
473         tcon = tlink_tcon(tlink);
474         server = tcon->ses->server;
475
476         if (server->ops->new_lease_key)
477                 server->ops->new_lease_key(&fid);
478
479         cifs_add_pending_open(&fid, tlink, &open);
480
481         rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,
482                             &oplock, &fid);
483
484         if (rc) {
485                 cifs_del_pending_open(&open);
486                 goto out;
487         }
488
489         if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
490                 *opened |= FILE_CREATED;
491
492         rc = finish_open(file, direntry, generic_file_open, opened);
493         if (rc) {
494                 if (server->ops->close)
495                         server->ops->close(xid, tcon, &fid);
496                 cifs_del_pending_open(&open);
497                 goto out;
498         }
499
500         if (file->f_flags & O_DIRECT &&
501             CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO) {
502                 if (CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
503                         file->f_op = &cifs_file_direct_nobrl_ops;
504                 else
505                         file->f_op = &cifs_file_direct_ops;
506                 }
507
508         file_info = cifs_new_fileinfo(&fid, file, tlink, oplock);
509         if (file_info == NULL) {
510                 if (server->ops->close)
511                         server->ops->close(xid, tcon, &fid);
512                 cifs_del_pending_open(&open);
513                 fput(file);
514                 rc = -ENOMEM;
515         }
516
517 out:
518         cifs_put_tlink(tlink);
519 out_free_xid:
520         free_xid(xid);
521         return rc;
522 }
523
524 int cifs_create(struct inode *inode, struct dentry *direntry, umode_t mode,
525                 bool excl)
526 {
527         int rc;
528         unsigned int xid = get_xid();
529         /*
530          * BB below access is probably too much for mknod to request
531          *    but we have to do query and setpathinfo so requesting
532          *    less could fail (unless we want to request getatr and setatr
533          *    permissions (only).  At least for POSIX we do not have to
534          *    request so much.
535          */
536         unsigned oflags = O_EXCL | O_CREAT | O_RDWR;
537         struct tcon_link *tlink;
538         struct cifs_tcon *tcon;
539         struct TCP_Server_Info *server;
540         struct cifs_fid fid;
541         __u32 oplock;
542
543         cifs_dbg(FYI, "cifs_create parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
544                  inode, direntry, direntry);
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
568 int cifs_mknod(struct inode *inode, struct dentry *direntry, umode_t mode,
569                 dev_t device_number)
570 {
571         int rc = -EPERM;
572         unsigned int xid;
573         int create_options = CREATE_NOT_DIR | CREATE_OPTION_SPECIAL;
574         struct cifs_sb_info *cifs_sb;
575         struct tcon_link *tlink;
576         struct cifs_tcon *tcon;
577         struct cifs_io_parms io_parms;
578         char *full_path = NULL;
579         struct inode *newinode = NULL;
580         __u32 oplock = 0;
581         struct cifs_fid fid;
582         struct cifs_open_parms oparms;
583         FILE_ALL_INFO *buf = NULL;
584         unsigned int bytes_written;
585         struct win_dev *pdev;
586         struct kvec iov[2];
587
588         if (!old_valid_dev(device_number))
589                 return -EINVAL;
590
591         cifs_sb = CIFS_SB(inode->i_sb);
592         tlink = cifs_sb_tlink(cifs_sb);
593         if (IS_ERR(tlink))
594                 return PTR_ERR(tlink);
595
596         tcon = tlink_tcon(tlink);
597
598         xid = get_xid();
599
600         full_path = build_path_from_dentry(direntry);
601         if (full_path == NULL) {
602                 rc = -ENOMEM;
603                 goto mknod_out;
604         }
605
606         if (tcon->unix_ext) {
607                 struct cifs_unix_set_info_args args = {
608                         .mode   = mode & ~current_umask(),
609                         .ctime  = NO_CHANGE_64,
610                         .atime  = NO_CHANGE_64,
611                         .mtime  = NO_CHANGE_64,
612                         .device = device_number,
613                 };
614                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
615                         args.uid = current_fsuid();
616                         args.gid = current_fsgid();
617                 } else {
618                         args.uid = INVALID_UID; /* no change */
619                         args.gid = INVALID_GID; /* no change */
620                 }
621                 rc = CIFSSMBUnixSetPathInfo(xid, tcon, full_path, &args,
622                                             cifs_sb->local_nls,
623                                             cifs_remap(cifs_sb));
624                 if (rc)
625                         goto mknod_out;
626
627                 rc = cifs_get_inode_info_unix(&newinode, full_path,
628                                                 inode->i_sb, xid);
629
630                 if (rc == 0)
631                         d_instantiate(direntry, newinode);
632                 goto mknod_out;
633         }
634
635         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL))
636                 goto mknod_out;
637
638
639         cifs_dbg(FYI, "sfu compat create special file\n");
640
641         buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
642         if (buf == NULL) {
643                 kfree(full_path);
644                 rc = -ENOMEM;
645                 free_xid(xid);
646                 return rc;
647         }
648
649         if (backup_cred(cifs_sb))
650                 create_options |= CREATE_OPEN_BACKUP_INTENT;
651
652         oparms.tcon = tcon;
653         oparms.cifs_sb = cifs_sb;
654         oparms.desired_access = GENERIC_WRITE;
655         oparms.create_options = create_options;
656         oparms.disposition = FILE_CREATE;
657         oparms.path = full_path;
658         oparms.fid = &fid;
659         oparms.reconnect = false;
660
661         if (tcon->ses->server->oplocks)
662                 oplock = REQ_OPLOCK;
663         else
664                 oplock = 0;
665         rc = tcon->ses->server->ops->open(xid, &oparms, &oplock, buf);
666         if (rc)
667                 goto mknod_out;
668
669         /*
670          * BB Do not bother to decode buf since no local inode yet to put
671          * timestamps in, but we can reuse it safely.
672          */
673
674         pdev = (struct win_dev *)buf;
675         io_parms.pid = current->tgid;
676         io_parms.tcon = tcon;
677         io_parms.offset = 0;
678         io_parms.length = sizeof(struct win_dev);
679         iov[1].iov_base = buf;
680         iov[1].iov_len = sizeof(struct win_dev);
681         if (S_ISCHR(mode)) {
682                 memcpy(pdev->type, "IntxCHR", 8);
683                 pdev->major = cpu_to_le64(MAJOR(device_number));
684                 pdev->minor = cpu_to_le64(MINOR(device_number));
685                 rc = tcon->ses->server->ops->sync_write(xid, &fid, &io_parms,
686                                                         &bytes_written, iov, 1);
687         } else if (S_ISBLK(mode)) {
688                 memcpy(pdev->type, "IntxBLK", 8);
689                 pdev->major = cpu_to_le64(MAJOR(device_number));
690                 pdev->minor = cpu_to_le64(MINOR(device_number));
691                 rc = tcon->ses->server->ops->sync_write(xid, &fid, &io_parms,
692                                                         &bytes_written, iov, 1);
693         } /* else if (S_ISFIFO) */
694         tcon->ses->server->ops->close(xid, tcon, &fid);
695         d_drop(direntry);
696
697         /* FIXME: add code here to set EAs */
698
699 mknod_out:
700         kfree(full_path);
701         kfree(buf);
702         free_xid(xid);
703         cifs_put_tlink(tlink);
704         return rc;
705 }
706
707 struct dentry *
708 cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
709             unsigned int flags)
710 {
711         unsigned int xid;
712         int rc = 0; /* to get around spurious gcc warning, set to zero here */
713         struct cifs_sb_info *cifs_sb;
714         struct tcon_link *tlink;
715         struct cifs_tcon *pTcon;
716         struct inode *newInode = NULL;
717         char *full_path = NULL;
718
719         xid = get_xid();
720
721         cifs_dbg(FYI, "parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
722                  parent_dir_inode, direntry, direntry);
723
724         /* check whether path exists */
725
726         cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
727         tlink = cifs_sb_tlink(cifs_sb);
728         if (IS_ERR(tlink)) {
729                 free_xid(xid);
730                 return (struct dentry *)tlink;
731         }
732         pTcon = tlink_tcon(tlink);
733
734         rc = check_name(direntry);
735         if (rc)
736                 goto lookup_out;
737
738         /* can not grab the rename sem here since it would
739         deadlock in the cases (beginning of sys_rename itself)
740         in which we already have the sb rename sem */
741         full_path = build_path_from_dentry(direntry);
742         if (full_path == NULL) {
743                 rc = -ENOMEM;
744                 goto lookup_out;
745         }
746
747         if (d_really_is_positive(direntry)) {
748                 cifs_dbg(FYI, "non-NULL inode in lookup\n");
749         } else {
750                 cifs_dbg(FYI, "NULL inode in lookup\n");
751         }
752         cifs_dbg(FYI, "Full path: %s inode = 0x%p\n",
753                  full_path, d_inode(direntry));
754
755         if (pTcon->unix_ext) {
756                 rc = cifs_get_inode_info_unix(&newInode, full_path,
757                                               parent_dir_inode->i_sb, xid);
758         } else {
759                 rc = cifs_get_inode_info(&newInode, full_path, NULL,
760                                 parent_dir_inode->i_sb, xid, NULL);
761         }
762
763         if ((rc == 0) && (newInode != NULL)) {
764                 d_add(direntry, newInode);
765                 /* since paths are not looked up by component - the parent
766                    directories are presumed to be good here */
767                 renew_parental_timestamps(direntry);
768
769         } else if (rc == -ENOENT) {
770                 rc = 0;
771                 direntry->d_time = jiffies;
772                 d_add(direntry, NULL);
773         /*      if it was once a directory (but how can we tell?) we could do
774                 shrink_dcache_parent(direntry); */
775         } else if (rc != -EACCES) {
776                 cifs_dbg(FYI, "Unexpected lookup error %d\n", rc);
777                 /* We special case check for Access Denied - since that
778                 is a common return code */
779         }
780
781 lookup_out:
782         kfree(full_path);
783         cifs_put_tlink(tlink);
784         free_xid(xid);
785         return ERR_PTR(rc);
786 }
787
788 static int
789 cifs_d_revalidate(struct dentry *direntry, unsigned int flags)
790 {
791         if (flags & LOOKUP_RCU)
792                 return -ECHILD;
793
794         if (d_really_is_positive(direntry)) {
795                 if (cifs_revalidate_dentry(direntry))
796                         return 0;
797                 else {
798                         /*
799                          * If the inode wasn't known to be a dfs entry when
800                          * the dentry was instantiated, such as when created
801                          * via ->readdir(), it needs to be set now since the
802                          * attributes will have been updated by
803                          * cifs_revalidate_dentry().
804                          */
805                         if (IS_AUTOMOUNT(d_inode(direntry)) &&
806                            !(direntry->d_flags & DCACHE_NEED_AUTOMOUNT)) {
807                                 spin_lock(&direntry->d_lock);
808                                 direntry->d_flags |= DCACHE_NEED_AUTOMOUNT;
809                                 spin_unlock(&direntry->d_lock);
810                         }
811
812                         return 1;
813                 }
814         }
815
816         /*
817          * This may be nfsd (or something), anyway, we can't see the
818          * intent of this. So, since this can be for creation, drop it.
819          */
820         if (!flags)
821                 return 0;
822
823         /*
824          * Drop the negative dentry, in order to make sure to use the
825          * case sensitive name which is specified by user if this is
826          * for creation.
827          */
828         if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
829                 return 0;
830
831         if (time_after(jiffies, direntry->d_time + HZ) || !lookupCacheEnabled)
832                 return 0;
833
834         return 1;
835 }
836
837 /* static int cifs_d_delete(struct dentry *direntry)
838 {
839         int rc = 0;
840
841         cifs_dbg(FYI, "In cifs d_delete, name = %pd\n", direntry);
842
843         return rc;
844 }     */
845
846 const struct dentry_operations cifs_dentry_ops = {
847         .d_revalidate = cifs_d_revalidate,
848         .d_automount = cifs_dfs_d_automount,
849 /* d_delete:       cifs_d_delete,      */ /* not needed except for debugging */
850 };
851
852 static int cifs_ci_hash(const struct dentry *dentry, struct qstr *q)
853 {
854         struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls;
855         unsigned long hash;
856         wchar_t c;
857         int i, charlen;
858
859         hash = init_name_hash();
860         for (i = 0; i < q->len; i += charlen) {
861                 charlen = codepage->char2uni(&q->name[i], q->len - i, &c);
862                 /* error out if we can't convert the character */
863                 if (unlikely(charlen < 0))
864                         return charlen;
865                 hash = partial_name_hash(cifs_toupper(c), hash);
866         }
867         q->hash = end_name_hash(hash);
868
869         return 0;
870 }
871
872 static int cifs_ci_compare(const struct dentry *parent, const struct dentry *dentry,
873                 unsigned int len, const char *str, const struct qstr *name)
874 {
875         struct nls_table *codepage = CIFS_SB(parent->d_sb)->local_nls;
876         wchar_t c1, c2;
877         int i, l1, l2;
878
879         /*
880          * We make the assumption here that uppercase characters in the local
881          * codepage are always the same length as their lowercase counterparts.
882          *
883          * If that's ever not the case, then this will fail to match it.
884          */
885         if (name->len != len)
886                 return 1;
887
888         for (i = 0; i < len; i += l1) {
889                 /* Convert characters in both strings to UTF-16. */
890                 l1 = codepage->char2uni(&str[i], len - i, &c1);
891                 l2 = codepage->char2uni(&name->name[i], name->len - i, &c2);
892
893                 /*
894                  * If we can't convert either character, just declare it to
895                  * be 1 byte long and compare the original byte.
896                  */
897                 if (unlikely(l1 < 0 && l2 < 0)) {
898                         if (str[i] != name->name[i])
899                                 return 1;
900                         l1 = 1;
901                         continue;
902                 }
903
904                 /*
905                  * Here, we again ass|u|me that upper/lowercase versions of
906                  * a character are the same length in the local NLS.
907                  */
908                 if (l1 != l2)
909                         return 1;
910
911                 /* Now compare uppercase versions of these characters */
912                 if (cifs_toupper(c1) != cifs_toupper(c2))
913                         return 1;
914         }
915
916         return 0;
917 }
918
919 const struct dentry_operations cifs_ci_dentry_ops = {
920         .d_revalidate = cifs_d_revalidate,
921         .d_hash = cifs_ci_hash,
922         .d_compare = cifs_ci_compare,
923         .d_automount = cifs_dfs_d_automount,
924 };