xref: /linux/fs/jfs/namei.c (revision 5e8c0fb6a95728b852d56c0a9244425d474670c0)
1 /*
2  *   Copyright (C) International Business Machines Corp., 2000-2004
3  *   Portions Copyright (C) Christoph Hellwig, 2001-2002
4  *
5  *   This program is free software;  you can redistribute it and/or modify
6  *   it under the terms of the GNU General Public License as published by
7  *   the Free Software Foundation; either version 2 of the License, or
8  *   (at your option) any later version.
9  *
10  *   This program is distributed in the hope that it will be useful,
11  *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
13  *   the GNU General Public License for more details.
14  *
15  *   You should have received a copy of the GNU General Public License
16  *   along with this program;  if not, write to the Free Software
17  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18  */
19 
20 #include <linux/fs.h>
21 #include <linux/namei.h>
22 #include <linux/ctype.h>
23 #include <linux/quotaops.h>
24 #include <linux/exportfs.h>
25 #include "jfs_incore.h"
26 #include "jfs_superblock.h"
27 #include "jfs_inode.h"
28 #include "jfs_dinode.h"
29 #include "jfs_dmap.h"
30 #include "jfs_unicode.h"
31 #include "jfs_metapage.h"
32 #include "jfs_xattr.h"
33 #include "jfs_acl.h"
34 #include "jfs_debug.h"
35 
36 /*
37  * forward references
38  */
39 const struct dentry_operations jfs_ci_dentry_operations;
40 
41 static s64 commitZeroLink(tid_t, struct inode *);
42 
43 /*
44  * NAME:	free_ea_wmap(inode)
45  *
46  * FUNCTION:	free uncommitted extended attributes from working map
47  *
48  */
49 static inline void free_ea_wmap(struct inode *inode)
50 {
51 	dxd_t *ea = &JFS_IP(inode)->ea;
52 
53 	if (ea->flag & DXD_EXTENT) {
54 		/* free EA pages from cache */
55 		invalidate_dxd_metapages(inode, *ea);
56 		dbFree(inode, addressDXD(ea), lengthDXD(ea));
57 	}
58 	ea->flag = 0;
59 }
60 
61 /*
62  * NAME:	jfs_create(dip, dentry, mode)
63  *
64  * FUNCTION:	create a regular file in the parent directory <dip>
65  *		with name = <from dentry> and mode = <mode>
66  *
67  * PARAMETER:	dip	- parent directory vnode
68  *		dentry	- dentry of new file
69  *		mode	- create mode (rwxrwxrwx).
70  *		nd- nd struct
71  *
72  * RETURN:	Errors from subroutines
73  *
74  */
75 static int jfs_create(struct inode *dip, struct dentry *dentry, umode_t mode,
76 		bool excl)
77 {
78 	int rc = 0;
79 	tid_t tid;		/* transaction id */
80 	struct inode *ip = NULL;	/* child directory inode */
81 	ino_t ino;
82 	struct component_name dname;	/* child directory name */
83 	struct btstack btstack;
84 	struct inode *iplist[2];
85 	struct tblock *tblk;
86 
87 	jfs_info("jfs_create: dip:0x%p name:%pd", dip, dentry);
88 
89 	dquot_initialize(dip);
90 
91 	/*
92 	 * search parent directory for entry/freespace
93 	 * (dtSearch() returns parent directory page pinned)
94 	 */
95 	if ((rc = get_UCSname(&dname, dentry)))
96 		goto out1;
97 
98 	/*
99 	 * Either iAlloc() or txBegin() may block.  Deadlock can occur if we
100 	 * block there while holding dtree page, so we allocate the inode &
101 	 * begin the transaction before we search the directory.
102 	 */
103 	ip = ialloc(dip, mode);
104 	if (IS_ERR(ip)) {
105 		rc = PTR_ERR(ip);
106 		goto out2;
107 	}
108 
109 	tid = txBegin(dip->i_sb, 0);
110 
111 	mutex_lock_nested(&JFS_IP(dip)->commit_mutex, COMMIT_MUTEX_PARENT);
112 	mutex_lock_nested(&JFS_IP(ip)->commit_mutex, COMMIT_MUTEX_CHILD);
113 
114 	rc = jfs_init_acl(tid, ip, dip);
115 	if (rc)
116 		goto out3;
117 
118 	rc = jfs_init_security(tid, ip, dip, &dentry->d_name);
119 	if (rc) {
120 		txAbort(tid, 0);
121 		goto out3;
122 	}
123 
124 	if ((rc = dtSearch(dip, &dname, &ino, &btstack, JFS_CREATE))) {
125 		jfs_err("jfs_create: dtSearch returned %d", rc);
126 		txAbort(tid, 0);
127 		goto out3;
128 	}
129 
130 	tblk = tid_to_tblock(tid);
131 	tblk->xflag |= COMMIT_CREATE;
132 	tblk->ino = ip->i_ino;
133 	tblk->u.ixpxd = JFS_IP(ip)->ixpxd;
134 
135 	iplist[0] = dip;
136 	iplist[1] = ip;
137 
138 	/*
139 	 * initialize the child XAD tree root in-line in inode
140 	 */
141 	xtInitRoot(tid, ip);
142 
143 	/*
144 	 * create entry in parent directory for child directory
145 	 * (dtInsert() releases parent directory page)
146 	 */
147 	ino = ip->i_ino;
148 	if ((rc = dtInsert(tid, dip, &dname, &ino, &btstack))) {
149 		if (rc == -EIO) {
150 			jfs_err("jfs_create: dtInsert returned -EIO");
151 			txAbort(tid, 1);	/* Marks Filesystem dirty */
152 		} else
153 			txAbort(tid, 0);	/* Filesystem full */
154 		goto out3;
155 	}
156 
157 	ip->i_op = &jfs_file_inode_operations;
158 	ip->i_fop = &jfs_file_operations;
159 	ip->i_mapping->a_ops = &jfs_aops;
160 
161 	mark_inode_dirty(ip);
162 
163 	dip->i_ctime = dip->i_mtime = CURRENT_TIME;
164 
165 	mark_inode_dirty(dip);
166 
167 	rc = txCommit(tid, 2, &iplist[0], 0);
168 
169       out3:
170 	txEnd(tid);
171 	mutex_unlock(&JFS_IP(ip)->commit_mutex);
172 	mutex_unlock(&JFS_IP(dip)->commit_mutex);
173 	if (rc) {
174 		free_ea_wmap(ip);
175 		clear_nlink(ip);
176 		unlock_new_inode(ip);
177 		iput(ip);
178 	} else {
179 		unlock_new_inode(ip);
180 		d_instantiate(dentry, ip);
181 	}
182 
183       out2:
184 	free_UCSname(&dname);
185 
186       out1:
187 
188 	jfs_info("jfs_create: rc:%d", rc);
189 	return rc;
190 }
191 
192 
193 /*
194  * NAME:	jfs_mkdir(dip, dentry, mode)
195  *
196  * FUNCTION:	create a child directory in the parent directory <dip>
197  *		with name = <from dentry> and mode = <mode>
198  *
199  * PARAMETER:	dip	- parent directory vnode
200  *		dentry	- dentry of child directory
201  *		mode	- create mode (rwxrwxrwx).
202  *
203  * RETURN:	Errors from subroutines
204  *
205  * note:
206  * EACCESS: user needs search+write permission on the parent directory
207  */
208 static int jfs_mkdir(struct inode *dip, struct dentry *dentry, umode_t mode)
209 {
210 	int rc = 0;
211 	tid_t tid;		/* transaction id */
212 	struct inode *ip = NULL;	/* child directory inode */
213 	ino_t ino;
214 	struct component_name dname;	/* child directory name */
215 	struct btstack btstack;
216 	struct inode *iplist[2];
217 	struct tblock *tblk;
218 
219 	jfs_info("jfs_mkdir: dip:0x%p name:%pd", dip, dentry);
220 
221 	dquot_initialize(dip);
222 
223 	/*
224 	 * search parent directory for entry/freespace
225 	 * (dtSearch() returns parent directory page pinned)
226 	 */
227 	if ((rc = get_UCSname(&dname, dentry)))
228 		goto out1;
229 
230 	/*
231 	 * Either iAlloc() or txBegin() may block.  Deadlock can occur if we
232 	 * block there while holding dtree page, so we allocate the inode &
233 	 * begin the transaction before we search the directory.
234 	 */
235 	ip = ialloc(dip, S_IFDIR | mode);
236 	if (IS_ERR(ip)) {
237 		rc = PTR_ERR(ip);
238 		goto out2;
239 	}
240 
241 	tid = txBegin(dip->i_sb, 0);
242 
243 	mutex_lock_nested(&JFS_IP(dip)->commit_mutex, COMMIT_MUTEX_PARENT);
244 	mutex_lock_nested(&JFS_IP(ip)->commit_mutex, COMMIT_MUTEX_CHILD);
245 
246 	rc = jfs_init_acl(tid, ip, dip);
247 	if (rc)
248 		goto out3;
249 
250 	rc = jfs_init_security(tid, ip, dip, &dentry->d_name);
251 	if (rc) {
252 		txAbort(tid, 0);
253 		goto out3;
254 	}
255 
256 	if ((rc = dtSearch(dip, &dname, &ino, &btstack, JFS_CREATE))) {
257 		jfs_err("jfs_mkdir: dtSearch returned %d", rc);
258 		txAbort(tid, 0);
259 		goto out3;
260 	}
261 
262 	tblk = tid_to_tblock(tid);
263 	tblk->xflag |= COMMIT_CREATE;
264 	tblk->ino = ip->i_ino;
265 	tblk->u.ixpxd = JFS_IP(ip)->ixpxd;
266 
267 	iplist[0] = dip;
268 	iplist[1] = ip;
269 
270 	/*
271 	 * initialize the child directory in-line in inode
272 	 */
273 	dtInitRoot(tid, ip, dip->i_ino);
274 
275 	/*
276 	 * create entry in parent directory for child directory
277 	 * (dtInsert() releases parent directory page)
278 	 */
279 	ino = ip->i_ino;
280 	if ((rc = dtInsert(tid, dip, &dname, &ino, &btstack))) {
281 		if (rc == -EIO) {
282 			jfs_err("jfs_mkdir: dtInsert returned -EIO");
283 			txAbort(tid, 1);	/* Marks Filesystem dirty */
284 		} else
285 			txAbort(tid, 0);	/* Filesystem full */
286 		goto out3;
287 	}
288 
289 	set_nlink(ip, 2);	/* for '.' */
290 	ip->i_op = &jfs_dir_inode_operations;
291 	ip->i_fop = &jfs_dir_operations;
292 
293 	mark_inode_dirty(ip);
294 
295 	/* update parent directory inode */
296 	inc_nlink(dip);		/* for '..' from child directory */
297 	dip->i_ctime = dip->i_mtime = CURRENT_TIME;
298 	mark_inode_dirty(dip);
299 
300 	rc = txCommit(tid, 2, &iplist[0], 0);
301 
302       out3:
303 	txEnd(tid);
304 	mutex_unlock(&JFS_IP(ip)->commit_mutex);
305 	mutex_unlock(&JFS_IP(dip)->commit_mutex);
306 	if (rc) {
307 		free_ea_wmap(ip);
308 		clear_nlink(ip);
309 		unlock_new_inode(ip);
310 		iput(ip);
311 	} else {
312 		unlock_new_inode(ip);
313 		d_instantiate(dentry, ip);
314 	}
315 
316       out2:
317 	free_UCSname(&dname);
318 
319 
320       out1:
321 
322 	jfs_info("jfs_mkdir: rc:%d", rc);
323 	return rc;
324 }
325 
326 /*
327  * NAME:	jfs_rmdir(dip, dentry)
328  *
329  * FUNCTION:	remove a link to child directory
330  *
331  * PARAMETER:	dip	- parent inode
332  *		dentry	- child directory dentry
333  *
334  * RETURN:	-EINVAL	- if name is . or ..
335  *		-EINVAL - if . or .. exist but are invalid.
336  *		errors from subroutines
337  *
338  * note:
339  * if other threads have the directory open when the last link
340  * is removed, the "." and ".." entries, if present, are removed before
341  * rmdir() returns and no new entries may be created in the directory,
342  * but the directory is not removed until the last reference to
343  * the directory is released (cf.unlink() of regular file).
344  */
345 static int jfs_rmdir(struct inode *dip, struct dentry *dentry)
346 {
347 	int rc;
348 	tid_t tid;		/* transaction id */
349 	struct inode *ip = dentry->d_inode;
350 	ino_t ino;
351 	struct component_name dname;
352 	struct inode *iplist[2];
353 	struct tblock *tblk;
354 
355 	jfs_info("jfs_rmdir: dip:0x%p name:%pd", dip, dentry);
356 
357 	/* Init inode for quota operations. */
358 	dquot_initialize(dip);
359 	dquot_initialize(ip);
360 
361 	/* directory must be empty to be removed */
362 	if (!dtEmpty(ip)) {
363 		rc = -ENOTEMPTY;
364 		goto out;
365 	}
366 
367 	if ((rc = get_UCSname(&dname, dentry))) {
368 		goto out;
369 	}
370 
371 	tid = txBegin(dip->i_sb, 0);
372 
373 	mutex_lock_nested(&JFS_IP(dip)->commit_mutex, COMMIT_MUTEX_PARENT);
374 	mutex_lock_nested(&JFS_IP(ip)->commit_mutex, COMMIT_MUTEX_CHILD);
375 
376 	iplist[0] = dip;
377 	iplist[1] = ip;
378 
379 	tblk = tid_to_tblock(tid);
380 	tblk->xflag |= COMMIT_DELETE;
381 	tblk->u.ip = ip;
382 
383 	/*
384 	 * delete the entry of target directory from parent directory
385 	 */
386 	ino = ip->i_ino;
387 	if ((rc = dtDelete(tid, dip, &dname, &ino, JFS_REMOVE))) {
388 		jfs_err("jfs_rmdir: dtDelete returned %d", rc);
389 		if (rc == -EIO)
390 			txAbort(tid, 1);
391 		txEnd(tid);
392 		mutex_unlock(&JFS_IP(ip)->commit_mutex);
393 		mutex_unlock(&JFS_IP(dip)->commit_mutex);
394 
395 		goto out2;
396 	}
397 
398 	/* update parent directory's link count corresponding
399 	 * to ".." entry of the target directory deleted
400 	 */
401 	dip->i_ctime = dip->i_mtime = CURRENT_TIME;
402 	inode_dec_link_count(dip);
403 
404 	/*
405 	 * OS/2 could have created EA and/or ACL
406 	 */
407 	/* free EA from both persistent and working map */
408 	if (JFS_IP(ip)->ea.flag & DXD_EXTENT) {
409 		/* free EA pages */
410 		txEA(tid, ip, &JFS_IP(ip)->ea, NULL);
411 	}
412 	JFS_IP(ip)->ea.flag = 0;
413 
414 	/* free ACL from both persistent and working map */
415 	if (JFS_IP(ip)->acl.flag & DXD_EXTENT) {
416 		/* free ACL pages */
417 		txEA(tid, ip, &JFS_IP(ip)->acl, NULL);
418 	}
419 	JFS_IP(ip)->acl.flag = 0;
420 
421 	/* mark the target directory as deleted */
422 	clear_nlink(ip);
423 	mark_inode_dirty(ip);
424 
425 	rc = txCommit(tid, 2, &iplist[0], 0);
426 
427 	txEnd(tid);
428 
429 	mutex_unlock(&JFS_IP(ip)->commit_mutex);
430 	mutex_unlock(&JFS_IP(dip)->commit_mutex);
431 
432 	/*
433 	 * Truncating the directory index table is not guaranteed.  It
434 	 * may need to be done iteratively
435 	 */
436 	if (test_cflag(COMMIT_Stale, dip)) {
437 		if (dip->i_size > 1)
438 			jfs_truncate_nolock(dip, 0);
439 
440 		clear_cflag(COMMIT_Stale, dip);
441 	}
442 
443       out2:
444 	free_UCSname(&dname);
445 
446       out:
447 	jfs_info("jfs_rmdir: rc:%d", rc);
448 	return rc;
449 }
450 
451 /*
452  * NAME:	jfs_unlink(dip, dentry)
453  *
454  * FUNCTION:	remove a link to object <vp> named by <name>
455  *		from parent directory <dvp>
456  *
457  * PARAMETER:	dip	- inode of parent directory
458  *		dentry	- dentry of object to be removed
459  *
460  * RETURN:	errors from subroutines
461  *
462  * note:
463  * temporary file: if one or more processes have the file open
464  * when the last link is removed, the link will be removed before
465  * unlink() returns, but the removal of the file contents will be
466  * postponed until all references to the files are closed.
467  *
468  * JFS does NOT support unlink() on directories.
469  *
470  */
471 static int jfs_unlink(struct inode *dip, struct dentry *dentry)
472 {
473 	int rc;
474 	tid_t tid;		/* transaction id */
475 	struct inode *ip = dentry->d_inode;
476 	ino_t ino;
477 	struct component_name dname;	/* object name */
478 	struct inode *iplist[2];
479 	struct tblock *tblk;
480 	s64 new_size = 0;
481 	int commit_flag;
482 
483 	jfs_info("jfs_unlink: dip:0x%p name:%pd", dip, dentry);
484 
485 	/* Init inode for quota operations. */
486 	dquot_initialize(dip);
487 	dquot_initialize(ip);
488 
489 	if ((rc = get_UCSname(&dname, dentry)))
490 		goto out;
491 
492 	IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
493 
494 	tid = txBegin(dip->i_sb, 0);
495 
496 	mutex_lock_nested(&JFS_IP(dip)->commit_mutex, COMMIT_MUTEX_PARENT);
497 	mutex_lock_nested(&JFS_IP(ip)->commit_mutex, COMMIT_MUTEX_CHILD);
498 
499 	iplist[0] = dip;
500 	iplist[1] = ip;
501 
502 	/*
503 	 * delete the entry of target file from parent directory
504 	 */
505 	ino = ip->i_ino;
506 	if ((rc = dtDelete(tid, dip, &dname, &ino, JFS_REMOVE))) {
507 		jfs_err("jfs_unlink: dtDelete returned %d", rc);
508 		if (rc == -EIO)
509 			txAbort(tid, 1);	/* Marks FS Dirty */
510 		txEnd(tid);
511 		mutex_unlock(&JFS_IP(ip)->commit_mutex);
512 		mutex_unlock(&JFS_IP(dip)->commit_mutex);
513 		IWRITE_UNLOCK(ip);
514 		goto out1;
515 	}
516 
517 	ASSERT(ip->i_nlink);
518 
519 	ip->i_ctime = dip->i_ctime = dip->i_mtime = CURRENT_TIME;
520 	mark_inode_dirty(dip);
521 
522 	/* update target's inode */
523 	inode_dec_link_count(ip);
524 
525 	/*
526 	 *	commit zero link count object
527 	 */
528 	if (ip->i_nlink == 0) {
529 		assert(!test_cflag(COMMIT_Nolink, ip));
530 		/* free block resources */
531 		if ((new_size = commitZeroLink(tid, ip)) < 0) {
532 			txAbort(tid, 1);	/* Marks FS Dirty */
533 			txEnd(tid);
534 			mutex_unlock(&JFS_IP(ip)->commit_mutex);
535 			mutex_unlock(&JFS_IP(dip)->commit_mutex);
536 			IWRITE_UNLOCK(ip);
537 			rc = new_size;
538 			goto out1;
539 		}
540 		tblk = tid_to_tblock(tid);
541 		tblk->xflag |= COMMIT_DELETE;
542 		tblk->u.ip = ip;
543 	}
544 
545 	/*
546 	 * Incomplete truncate of file data can
547 	 * result in timing problems unless we synchronously commit the
548 	 * transaction.
549 	 */
550 	if (new_size)
551 		commit_flag = COMMIT_SYNC;
552 	else
553 		commit_flag = 0;
554 
555 	/*
556 	 * If xtTruncate was incomplete, commit synchronously to avoid
557 	 * timing complications
558 	 */
559 	rc = txCommit(tid, 2, &iplist[0], commit_flag);
560 
561 	txEnd(tid);
562 
563 	mutex_unlock(&JFS_IP(ip)->commit_mutex);
564 	mutex_unlock(&JFS_IP(dip)->commit_mutex);
565 
566 	while (new_size && (rc == 0)) {
567 		tid = txBegin(dip->i_sb, 0);
568 		mutex_lock(&JFS_IP(ip)->commit_mutex);
569 		new_size = xtTruncate_pmap(tid, ip, new_size);
570 		if (new_size < 0) {
571 			txAbort(tid, 1);	/* Marks FS Dirty */
572 			rc = new_size;
573 		} else
574 			rc = txCommit(tid, 2, &iplist[0], COMMIT_SYNC);
575 		txEnd(tid);
576 		mutex_unlock(&JFS_IP(ip)->commit_mutex);
577 	}
578 
579 	if (ip->i_nlink == 0)
580 		set_cflag(COMMIT_Nolink, ip);
581 
582 	IWRITE_UNLOCK(ip);
583 
584 	/*
585 	 * Truncating the directory index table is not guaranteed.  It
586 	 * may need to be done iteratively
587 	 */
588 	if (test_cflag(COMMIT_Stale, dip)) {
589 		if (dip->i_size > 1)
590 			jfs_truncate_nolock(dip, 0);
591 
592 		clear_cflag(COMMIT_Stale, dip);
593 	}
594 
595       out1:
596 	free_UCSname(&dname);
597       out:
598 	jfs_info("jfs_unlink: rc:%d", rc);
599 	return rc;
600 }
601 
602 /*
603  * NAME:	commitZeroLink()
604  *
605  * FUNCTION:	for non-directory, called by jfs_remove(),
606  *		truncate a regular file, directory or symbolic
607  *		link to zero length. return 0 if type is not
608  *		one of these.
609  *
610  *		if the file is currently associated with a VM segment
611  *		only permanent disk and inode map resources are freed,
612  *		and neither the inode nor indirect blocks are modified
613  *		so that the resources can be later freed in the work
614  *		map by ctrunc1.
615  *		if there is no VM segment on entry, the resources are
616  *		freed in both work and permanent map.
617  *		(? for temporary file - memory object is cached even
618  *		after no reference:
619  *		reference count > 0 -   )
620  *
621  * PARAMETERS:	cd	- pointer to commit data structure.
622  *			  current inode is the one to truncate.
623  *
624  * RETURN:	Errors from subroutines
625  */
626 static s64 commitZeroLink(tid_t tid, struct inode *ip)
627 {
628 	int filetype;
629 	struct tblock *tblk;
630 
631 	jfs_info("commitZeroLink: tid = %d, ip = 0x%p", tid, ip);
632 
633 	filetype = ip->i_mode & S_IFMT;
634 	switch (filetype) {
635 	case S_IFREG:
636 		break;
637 	case S_IFLNK:
638 		/* fast symbolic link */
639 		if (ip->i_size < IDATASIZE) {
640 			ip->i_size = 0;
641 			return 0;
642 		}
643 		break;
644 	default:
645 		assert(filetype != S_IFDIR);
646 		return 0;
647 	}
648 
649 	set_cflag(COMMIT_Freewmap, ip);
650 
651 	/* mark transaction of block map update type */
652 	tblk = tid_to_tblock(tid);
653 	tblk->xflag |= COMMIT_PMAP;
654 
655 	/*
656 	 * free EA
657 	 */
658 	if (JFS_IP(ip)->ea.flag & DXD_EXTENT)
659 		/* acquire maplock on EA to be freed from block map */
660 		txEA(tid, ip, &JFS_IP(ip)->ea, NULL);
661 
662 	/*
663 	 * free ACL
664 	 */
665 	if (JFS_IP(ip)->acl.flag & DXD_EXTENT)
666 		/* acquire maplock on EA to be freed from block map */
667 		txEA(tid, ip, &JFS_IP(ip)->acl, NULL);
668 
669 	/*
670 	 * free xtree/data (truncate to zero length):
671 	 * free xtree/data pages from cache if COMMIT_PWMAP,
672 	 * free xtree/data blocks from persistent block map, and
673 	 * free xtree/data blocks from working block map if COMMIT_PWMAP;
674 	 */
675 	if (ip->i_size)
676 		return xtTruncate_pmap(tid, ip, 0);
677 
678 	return 0;
679 }
680 
681 
682 /*
683  * NAME:	jfs_free_zero_link()
684  *
685  * FUNCTION:	for non-directory, called by iClose(),
686  *		free resources of a file from cache and WORKING map
687  *		for a file previously committed with zero link count
688  *		while associated with a pager object,
689  *
690  * PARAMETER:	ip	- pointer to inode of file.
691  */
692 void jfs_free_zero_link(struct inode *ip)
693 {
694 	int type;
695 
696 	jfs_info("jfs_free_zero_link: ip = 0x%p", ip);
697 
698 	/* return if not reg or symbolic link or if size is
699 	 * already ok.
700 	 */
701 	type = ip->i_mode & S_IFMT;
702 
703 	switch (type) {
704 	case S_IFREG:
705 		break;
706 	case S_IFLNK:
707 		/* if its contained in inode nothing to do */
708 		if (ip->i_size < IDATASIZE)
709 			return;
710 		break;
711 	default:
712 		return;
713 	}
714 
715 	/*
716 	 * free EA
717 	 */
718 	if (JFS_IP(ip)->ea.flag & DXD_EXTENT) {
719 		s64 xaddr = addressDXD(&JFS_IP(ip)->ea);
720 		int xlen = lengthDXD(&JFS_IP(ip)->ea);
721 		struct maplock maplock;	/* maplock for COMMIT_WMAP */
722 		struct pxd_lock *pxdlock;	/* maplock for COMMIT_WMAP */
723 
724 		/* free EA pages from cache */
725 		invalidate_dxd_metapages(ip, JFS_IP(ip)->ea);
726 
727 		/* free EA extent from working block map */
728 		maplock.index = 1;
729 		pxdlock = (struct pxd_lock *) & maplock;
730 		pxdlock->flag = mlckFREEPXD;
731 		PXDaddress(&pxdlock->pxd, xaddr);
732 		PXDlength(&pxdlock->pxd, xlen);
733 		txFreeMap(ip, pxdlock, NULL, COMMIT_WMAP);
734 	}
735 
736 	/*
737 	 * free ACL
738 	 */
739 	if (JFS_IP(ip)->acl.flag & DXD_EXTENT) {
740 		s64 xaddr = addressDXD(&JFS_IP(ip)->acl);
741 		int xlen = lengthDXD(&JFS_IP(ip)->acl);
742 		struct maplock maplock;	/* maplock for COMMIT_WMAP */
743 		struct pxd_lock *pxdlock;	/* maplock for COMMIT_WMAP */
744 
745 		invalidate_dxd_metapages(ip, JFS_IP(ip)->acl);
746 
747 		/* free ACL extent from working block map */
748 		maplock.index = 1;
749 		pxdlock = (struct pxd_lock *) & maplock;
750 		pxdlock->flag = mlckFREEPXD;
751 		PXDaddress(&pxdlock->pxd, xaddr);
752 		PXDlength(&pxdlock->pxd, xlen);
753 		txFreeMap(ip, pxdlock, NULL, COMMIT_WMAP);
754 	}
755 
756 	/*
757 	 * free xtree/data (truncate to zero length):
758 	 * free xtree/data pages from cache, and
759 	 * free xtree/data blocks from working block map;
760 	 */
761 	if (ip->i_size)
762 		xtTruncate(0, ip, 0, COMMIT_WMAP);
763 }
764 
765 /*
766  * NAME:	jfs_link(vp, dvp, name, crp)
767  *
768  * FUNCTION:	create a link to <vp> by the name = <name>
769  *		in the parent directory <dvp>
770  *
771  * PARAMETER:	vp	- target object
772  *		dvp	- parent directory of new link
773  *		name	- name of new link to target object
774  *		crp	- credential
775  *
776  * RETURN:	Errors from subroutines
777  *
778  * note:
779  * JFS does NOT support link() on directories (to prevent circular
780  * path in the directory hierarchy);
781  * EPERM: the target object is a directory, and either the caller
782  * does not have appropriate privileges or the implementation prohibits
783  * using link() on directories [XPG4.2].
784  *
785  * JFS does NOT support links between file systems:
786  * EXDEV: target object and new link are on different file systems and
787  * implementation does not support links between file systems [XPG4.2].
788  */
789 static int jfs_link(struct dentry *old_dentry,
790 	     struct inode *dir, struct dentry *dentry)
791 {
792 	int rc;
793 	tid_t tid;
794 	struct inode *ip = old_dentry->d_inode;
795 	ino_t ino;
796 	struct component_name dname;
797 	struct btstack btstack;
798 	struct inode *iplist[2];
799 
800 	jfs_info("jfs_link: %pd %pd", old_dentry, dentry);
801 
802 	dquot_initialize(dir);
803 
804 	tid = txBegin(ip->i_sb, 0);
805 
806 	mutex_lock_nested(&JFS_IP(dir)->commit_mutex, COMMIT_MUTEX_PARENT);
807 	mutex_lock_nested(&JFS_IP(ip)->commit_mutex, COMMIT_MUTEX_CHILD);
808 
809 	/*
810 	 * scan parent directory for entry/freespace
811 	 */
812 	if ((rc = get_UCSname(&dname, dentry)))
813 		goto out;
814 
815 	if ((rc = dtSearch(dir, &dname, &ino, &btstack, JFS_CREATE)))
816 		goto free_dname;
817 
818 	/*
819 	 * create entry for new link in parent directory
820 	 */
821 	ino = ip->i_ino;
822 	if ((rc = dtInsert(tid, dir, &dname, &ino, &btstack)))
823 		goto free_dname;
824 
825 	/* update object inode */
826 	inc_nlink(ip);		/* for new link */
827 	ip->i_ctime = CURRENT_TIME;
828 	dir->i_ctime = dir->i_mtime = CURRENT_TIME;
829 	mark_inode_dirty(dir);
830 	ihold(ip);
831 
832 	iplist[0] = ip;
833 	iplist[1] = dir;
834 	rc = txCommit(tid, 2, &iplist[0], 0);
835 
836 	if (rc) {
837 		drop_nlink(ip); /* never instantiated */
838 		iput(ip);
839 	} else
840 		d_instantiate(dentry, ip);
841 
842       free_dname:
843 	free_UCSname(&dname);
844 
845       out:
846 	txEnd(tid);
847 
848 	mutex_unlock(&JFS_IP(ip)->commit_mutex);
849 	mutex_unlock(&JFS_IP(dir)->commit_mutex);
850 
851 	jfs_info("jfs_link: rc:%d", rc);
852 	return rc;
853 }
854 
855 /*
856  * NAME:	jfs_symlink(dip, dentry, name)
857  *
858  * FUNCTION:	creates a symbolic link to <symlink> by name <name>
859  *			in directory <dip>
860  *
861  * PARAMETER:	dip	- parent directory vnode
862  *		dentry	- dentry of symbolic link
863  *		name	- the path name of the existing object
864  *			  that will be the source of the link
865  *
866  * RETURN:	errors from subroutines
867  *
868  * note:
869  * ENAMETOOLONG: pathname resolution of a symbolic link produced
870  * an intermediate result whose length exceeds PATH_MAX [XPG4.2]
871 */
872 
873 static int jfs_symlink(struct inode *dip, struct dentry *dentry,
874 		const char *name)
875 {
876 	int rc;
877 	tid_t tid;
878 	ino_t ino = 0;
879 	struct component_name dname;
880 	int ssize;		/* source pathname size */
881 	struct btstack btstack;
882 	struct inode *ip = dentry->d_inode;
883 	unchar *i_fastsymlink;
884 	s64 xlen = 0;
885 	int bmask = 0, xsize;
886 	s64 xaddr;
887 	struct metapage *mp;
888 	struct super_block *sb;
889 	struct tblock *tblk;
890 
891 	struct inode *iplist[2];
892 
893 	jfs_info("jfs_symlink: dip:0x%p name:%s", dip, name);
894 
895 	dquot_initialize(dip);
896 
897 	ssize = strlen(name) + 1;
898 
899 	/*
900 	 * search parent directory for entry/freespace
901 	 * (dtSearch() returns parent directory page pinned)
902 	 */
903 
904 	if ((rc = get_UCSname(&dname, dentry)))
905 		goto out1;
906 
907 	/*
908 	 * allocate on-disk/in-memory inode for symbolic link:
909 	 * (iAlloc() returns new, locked inode)
910 	 */
911 	ip = ialloc(dip, S_IFLNK | 0777);
912 	if (IS_ERR(ip)) {
913 		rc = PTR_ERR(ip);
914 		goto out2;
915 	}
916 
917 	tid = txBegin(dip->i_sb, 0);
918 
919 	mutex_lock_nested(&JFS_IP(dip)->commit_mutex, COMMIT_MUTEX_PARENT);
920 	mutex_lock_nested(&JFS_IP(ip)->commit_mutex, COMMIT_MUTEX_CHILD);
921 
922 	rc = jfs_init_security(tid, ip, dip, &dentry->d_name);
923 	if (rc)
924 		goto out3;
925 
926 	tblk = tid_to_tblock(tid);
927 	tblk->xflag |= COMMIT_CREATE;
928 	tblk->ino = ip->i_ino;
929 	tblk->u.ixpxd = JFS_IP(ip)->ixpxd;
930 
931 	/* fix symlink access permission
932 	 * (dir_create() ANDs in the u.u_cmask,
933 	 * but symlinks really need to be 777 access)
934 	 */
935 	ip->i_mode |= 0777;
936 
937 	/*
938 	 * write symbolic link target path name
939 	 */
940 	xtInitRoot(tid, ip);
941 
942 	/*
943 	 * write source path name inline in on-disk inode (fast symbolic link)
944 	 */
945 
946 	if (ssize <= IDATASIZE) {
947 		ip->i_op = &jfs_fast_symlink_inode_operations;
948 
949 		i_fastsymlink = JFS_IP(ip)->i_inline;
950 		memcpy(i_fastsymlink, name, ssize);
951 		ip->i_size = ssize - 1;
952 
953 		/*
954 		 * if symlink is > 128 bytes, we don't have the space to
955 		 * store inline extended attributes
956 		 */
957 		if (ssize > sizeof (JFS_IP(ip)->i_inline))
958 			JFS_IP(ip)->mode2 &= ~INLINEEA;
959 
960 		jfs_info("jfs_symlink: fast symlink added  ssize:%d name:%s ",
961 			 ssize, name);
962 	}
963 	/*
964 	 * write source path name in a single extent
965 	 */
966 	else {
967 		jfs_info("jfs_symlink: allocate extent ip:0x%p", ip);
968 
969 		ip->i_op = &jfs_symlink_inode_operations;
970 		ip->i_mapping->a_ops = &jfs_aops;
971 
972 		/*
973 		 * even though the data of symlink object (source
974 		 * path name) is treated as non-journaled user data,
975 		 * it is read/written thru buffer cache for performance.
976 		 */
977 		sb = ip->i_sb;
978 		bmask = JFS_SBI(sb)->bsize - 1;
979 		xsize = (ssize + bmask) & ~bmask;
980 		xaddr = 0;
981 		xlen = xsize >> JFS_SBI(sb)->l2bsize;
982 		if ((rc = xtInsert(tid, ip, 0, 0, xlen, &xaddr, 0))) {
983 			txAbort(tid, 0);
984 			goto out3;
985 		}
986 		ip->i_size = ssize - 1;
987 		while (ssize) {
988 			/* This is kind of silly since PATH_MAX == 4K */
989 			int copy_size = min(ssize, PSIZE);
990 
991 			mp = get_metapage(ip, xaddr, PSIZE, 1);
992 
993 			if (mp == NULL) {
994 				xtTruncate(tid, ip, 0, COMMIT_PWMAP);
995 				rc = -EIO;
996 				txAbort(tid, 0);
997 				goto out3;
998 			}
999 			memcpy(mp->data, name, copy_size);
1000 			flush_metapage(mp);
1001 			ssize -= copy_size;
1002 			name += copy_size;
1003 			xaddr += JFS_SBI(sb)->nbperpage;
1004 		}
1005 	}
1006 
1007 	/*
1008 	 * create entry for symbolic link in parent directory
1009 	 */
1010 	rc = dtSearch(dip, &dname, &ino, &btstack, JFS_CREATE);
1011 	if (rc == 0) {
1012 		ino = ip->i_ino;
1013 		rc = dtInsert(tid, dip, &dname, &ino, &btstack);
1014 	}
1015 	if (rc) {
1016 		if (xlen)
1017 			xtTruncate(tid, ip, 0, COMMIT_PWMAP);
1018 		txAbort(tid, 0);
1019 		/* discard new inode */
1020 		goto out3;
1021 	}
1022 
1023 	mark_inode_dirty(ip);
1024 
1025 	dip->i_ctime = dip->i_mtime = CURRENT_TIME;
1026 	mark_inode_dirty(dip);
1027 	/*
1028 	 * commit update of parent directory and link object
1029 	 */
1030 
1031 	iplist[0] = dip;
1032 	iplist[1] = ip;
1033 	rc = txCommit(tid, 2, &iplist[0], 0);
1034 
1035       out3:
1036 	txEnd(tid);
1037 	mutex_unlock(&JFS_IP(ip)->commit_mutex);
1038 	mutex_unlock(&JFS_IP(dip)->commit_mutex);
1039 	if (rc) {
1040 		free_ea_wmap(ip);
1041 		clear_nlink(ip);
1042 		unlock_new_inode(ip);
1043 		iput(ip);
1044 	} else {
1045 		unlock_new_inode(ip);
1046 		d_instantiate(dentry, ip);
1047 	}
1048 
1049       out2:
1050 	free_UCSname(&dname);
1051 
1052       out1:
1053 	jfs_info("jfs_symlink: rc:%d", rc);
1054 	return rc;
1055 }
1056 
1057 
1058 /*
1059  * NAME:	jfs_rename
1060  *
1061  * FUNCTION:	rename a file or directory
1062  */
1063 static int jfs_rename(struct inode *old_dir, struct dentry *old_dentry,
1064 	       struct inode *new_dir, struct dentry *new_dentry)
1065 {
1066 	struct btstack btstack;
1067 	ino_t ino;
1068 	struct component_name new_dname;
1069 	struct inode *new_ip;
1070 	struct component_name old_dname;
1071 	struct inode *old_ip;
1072 	int rc;
1073 	tid_t tid;
1074 	struct tlock *tlck;
1075 	struct dt_lock *dtlck;
1076 	struct lv *lv;
1077 	int ipcount;
1078 	struct inode *iplist[4];
1079 	struct tblock *tblk;
1080 	s64 new_size = 0;
1081 	int commit_flag;
1082 
1083 
1084 	jfs_info("jfs_rename: %pd %pd", old_dentry, new_dentry);
1085 
1086 	dquot_initialize(old_dir);
1087 	dquot_initialize(new_dir);
1088 
1089 	old_ip = old_dentry->d_inode;
1090 	new_ip = new_dentry->d_inode;
1091 
1092 	if ((rc = get_UCSname(&old_dname, old_dentry)))
1093 		goto out1;
1094 
1095 	if ((rc = get_UCSname(&new_dname, new_dentry)))
1096 		goto out2;
1097 
1098 	/*
1099 	 * Make sure source inode number is what we think it is
1100 	 */
1101 	rc = dtSearch(old_dir, &old_dname, &ino, &btstack, JFS_LOOKUP);
1102 	if (rc || (ino != old_ip->i_ino)) {
1103 		rc = -ENOENT;
1104 		goto out3;
1105 	}
1106 
1107 	/*
1108 	 * Make sure dest inode number (if any) is what we think it is
1109 	 */
1110 	rc = dtSearch(new_dir, &new_dname, &ino, &btstack, JFS_LOOKUP);
1111 	if (!rc) {
1112 		if ((!new_ip) || (ino != new_ip->i_ino)) {
1113 			rc = -ESTALE;
1114 			goto out3;
1115 		}
1116 	} else if (rc != -ENOENT)
1117 		goto out3;
1118 	else if (new_ip) {
1119 		/* no entry exists, but one was expected */
1120 		rc = -ESTALE;
1121 		goto out3;
1122 	}
1123 
1124 	if (S_ISDIR(old_ip->i_mode)) {
1125 		if (new_ip) {
1126 			if (!dtEmpty(new_ip)) {
1127 				rc = -ENOTEMPTY;
1128 				goto out3;
1129 			}
1130 		}
1131 	} else if (new_ip) {
1132 		IWRITE_LOCK(new_ip, RDWRLOCK_NORMAL);
1133 		/* Init inode for quota operations. */
1134 		dquot_initialize(new_ip);
1135 	}
1136 
1137 	/*
1138 	 * The real work starts here
1139 	 */
1140 	tid = txBegin(new_dir->i_sb, 0);
1141 
1142 	/*
1143 	 * How do we know the locking is safe from deadlocks?
1144 	 * The vfs does the hard part for us.  Any time we are taking nested
1145 	 * commit_mutexes, the vfs already has i_mutex held on the parent.
1146 	 * Here, the vfs has already taken i_mutex on both old_dir and new_dir.
1147 	 */
1148 	mutex_lock_nested(&JFS_IP(new_dir)->commit_mutex, COMMIT_MUTEX_PARENT);
1149 	mutex_lock_nested(&JFS_IP(old_ip)->commit_mutex, COMMIT_MUTEX_CHILD);
1150 	if (old_dir != new_dir)
1151 		mutex_lock_nested(&JFS_IP(old_dir)->commit_mutex,
1152 				  COMMIT_MUTEX_SECOND_PARENT);
1153 
1154 	if (new_ip) {
1155 		mutex_lock_nested(&JFS_IP(new_ip)->commit_mutex,
1156 				  COMMIT_MUTEX_VICTIM);
1157 		/*
1158 		 * Change existing directory entry to new inode number
1159 		 */
1160 		ino = new_ip->i_ino;
1161 		rc = dtModify(tid, new_dir, &new_dname, &ino,
1162 			      old_ip->i_ino, JFS_RENAME);
1163 		if (rc)
1164 			goto out4;
1165 		drop_nlink(new_ip);
1166 		if (S_ISDIR(new_ip->i_mode)) {
1167 			drop_nlink(new_ip);
1168 			if (new_ip->i_nlink) {
1169 				mutex_unlock(&JFS_IP(new_ip)->commit_mutex);
1170 				if (old_dir != new_dir)
1171 					mutex_unlock(&JFS_IP(old_dir)->commit_mutex);
1172 				mutex_unlock(&JFS_IP(old_ip)->commit_mutex);
1173 				mutex_unlock(&JFS_IP(new_dir)->commit_mutex);
1174 				if (!S_ISDIR(old_ip->i_mode) && new_ip)
1175 					IWRITE_UNLOCK(new_ip);
1176 				jfs_error(new_ip->i_sb,
1177 					  "new_ip->i_nlink != 0\n");
1178 				return -EIO;
1179 			}
1180 			tblk = tid_to_tblock(tid);
1181 			tblk->xflag |= COMMIT_DELETE;
1182 			tblk->u.ip = new_ip;
1183 		} else if (new_ip->i_nlink == 0) {
1184 			assert(!test_cflag(COMMIT_Nolink, new_ip));
1185 			/* free block resources */
1186 			if ((new_size = commitZeroLink(tid, new_ip)) < 0) {
1187 				txAbort(tid, 1);	/* Marks FS Dirty */
1188 				rc = new_size;
1189 				goto out4;
1190 			}
1191 			tblk = tid_to_tblock(tid);
1192 			tblk->xflag |= COMMIT_DELETE;
1193 			tblk->u.ip = new_ip;
1194 		} else {
1195 			new_ip->i_ctime = CURRENT_TIME;
1196 			mark_inode_dirty(new_ip);
1197 		}
1198 	} else {
1199 		/*
1200 		 * Add new directory entry
1201 		 */
1202 		rc = dtSearch(new_dir, &new_dname, &ino, &btstack,
1203 			      JFS_CREATE);
1204 		if (rc) {
1205 			jfs_err("jfs_rename didn't expect dtSearch to fail "
1206 				"w/rc = %d", rc);
1207 			goto out4;
1208 		}
1209 
1210 		ino = old_ip->i_ino;
1211 		rc = dtInsert(tid, new_dir, &new_dname, &ino, &btstack);
1212 		if (rc) {
1213 			if (rc == -EIO)
1214 				jfs_err("jfs_rename: dtInsert returned -EIO");
1215 			goto out4;
1216 		}
1217 		if (S_ISDIR(old_ip->i_mode))
1218 			inc_nlink(new_dir);
1219 	}
1220 	/*
1221 	 * Remove old directory entry
1222 	 */
1223 
1224 	ino = old_ip->i_ino;
1225 	rc = dtDelete(tid, old_dir, &old_dname, &ino, JFS_REMOVE);
1226 	if (rc) {
1227 		jfs_err("jfs_rename did not expect dtDelete to return rc = %d",
1228 			rc);
1229 		txAbort(tid, 1);	/* Marks Filesystem dirty */
1230 		goto out4;
1231 	}
1232 	if (S_ISDIR(old_ip->i_mode)) {
1233 		drop_nlink(old_dir);
1234 		if (old_dir != new_dir) {
1235 			/*
1236 			 * Change inode number of parent for moved directory
1237 			 */
1238 
1239 			JFS_IP(old_ip)->i_dtroot.header.idotdot =
1240 				cpu_to_le32(new_dir->i_ino);
1241 
1242 			/* Linelock header of dtree */
1243 			tlck = txLock(tid, old_ip,
1244 				    (struct metapage *) &JFS_IP(old_ip)->bxflag,
1245 				      tlckDTREE | tlckBTROOT | tlckRELINK);
1246 			dtlck = (struct dt_lock *) & tlck->lock;
1247 			ASSERT(dtlck->index == 0);
1248 			lv = & dtlck->lv[0];
1249 			lv->offset = 0;
1250 			lv->length = 1;
1251 			dtlck->index++;
1252 		}
1253 	}
1254 
1255 	/*
1256 	 * Update ctime on changed/moved inodes & mark dirty
1257 	 */
1258 	old_ip->i_ctime = CURRENT_TIME;
1259 	mark_inode_dirty(old_ip);
1260 
1261 	new_dir->i_ctime = new_dir->i_mtime = current_fs_time(new_dir->i_sb);
1262 	mark_inode_dirty(new_dir);
1263 
1264 	/* Build list of inodes modified by this transaction */
1265 	ipcount = 0;
1266 	iplist[ipcount++] = old_ip;
1267 	if (new_ip)
1268 		iplist[ipcount++] = new_ip;
1269 	iplist[ipcount++] = old_dir;
1270 
1271 	if (old_dir != new_dir) {
1272 		iplist[ipcount++] = new_dir;
1273 		old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME;
1274 		mark_inode_dirty(old_dir);
1275 	}
1276 
1277 	/*
1278 	 * Incomplete truncate of file data can
1279 	 * result in timing problems unless we synchronously commit the
1280 	 * transaction.
1281 	 */
1282 	if (new_size)
1283 		commit_flag = COMMIT_SYNC;
1284 	else
1285 		commit_flag = 0;
1286 
1287 	rc = txCommit(tid, ipcount, iplist, commit_flag);
1288 
1289       out4:
1290 	txEnd(tid);
1291 	if (new_ip)
1292 		mutex_unlock(&JFS_IP(new_ip)->commit_mutex);
1293 	if (old_dir != new_dir)
1294 		mutex_unlock(&JFS_IP(old_dir)->commit_mutex);
1295 	mutex_unlock(&JFS_IP(old_ip)->commit_mutex);
1296 	mutex_unlock(&JFS_IP(new_dir)->commit_mutex);
1297 
1298 	while (new_size && (rc == 0)) {
1299 		tid = txBegin(new_ip->i_sb, 0);
1300 		mutex_lock(&JFS_IP(new_ip)->commit_mutex);
1301 		new_size = xtTruncate_pmap(tid, new_ip, new_size);
1302 		if (new_size < 0) {
1303 			txAbort(tid, 1);
1304 			rc = new_size;
1305 		} else
1306 			rc = txCommit(tid, 1, &new_ip, COMMIT_SYNC);
1307 		txEnd(tid);
1308 		mutex_unlock(&JFS_IP(new_ip)->commit_mutex);
1309 	}
1310 	if (new_ip && (new_ip->i_nlink == 0))
1311 		set_cflag(COMMIT_Nolink, new_ip);
1312       out3:
1313 	free_UCSname(&new_dname);
1314       out2:
1315 	free_UCSname(&old_dname);
1316       out1:
1317 	if (new_ip && !S_ISDIR(new_ip->i_mode))
1318 		IWRITE_UNLOCK(new_ip);
1319 	/*
1320 	 * Truncating the directory index table is not guaranteed.  It
1321 	 * may need to be done iteratively
1322 	 */
1323 	if (test_cflag(COMMIT_Stale, old_dir)) {
1324 		if (old_dir->i_size > 1)
1325 			jfs_truncate_nolock(old_dir, 0);
1326 
1327 		clear_cflag(COMMIT_Stale, old_dir);
1328 	}
1329 
1330 	jfs_info("jfs_rename: returning %d", rc);
1331 	return rc;
1332 }
1333 
1334 
1335 /*
1336  * NAME:	jfs_mknod
1337  *
1338  * FUNCTION:	Create a special file (device)
1339  */
1340 static int jfs_mknod(struct inode *dir, struct dentry *dentry,
1341 		umode_t mode, dev_t rdev)
1342 {
1343 	struct jfs_inode_info *jfs_ip;
1344 	struct btstack btstack;
1345 	struct component_name dname;
1346 	ino_t ino;
1347 	struct inode *ip;
1348 	struct inode *iplist[2];
1349 	int rc;
1350 	tid_t tid;
1351 	struct tblock *tblk;
1352 
1353 	if (!new_valid_dev(rdev))
1354 		return -EINVAL;
1355 
1356 	jfs_info("jfs_mknod: %pd", dentry);
1357 
1358 	dquot_initialize(dir);
1359 
1360 	if ((rc = get_UCSname(&dname, dentry)))
1361 		goto out;
1362 
1363 	ip = ialloc(dir, mode);
1364 	if (IS_ERR(ip)) {
1365 		rc = PTR_ERR(ip);
1366 		goto out1;
1367 	}
1368 	jfs_ip = JFS_IP(ip);
1369 
1370 	tid = txBegin(dir->i_sb, 0);
1371 
1372 	mutex_lock_nested(&JFS_IP(dir)->commit_mutex, COMMIT_MUTEX_PARENT);
1373 	mutex_lock_nested(&JFS_IP(ip)->commit_mutex, COMMIT_MUTEX_CHILD);
1374 
1375 	rc = jfs_init_acl(tid, ip, dir);
1376 	if (rc)
1377 		goto out3;
1378 
1379 	rc = jfs_init_security(tid, ip, dir, &dentry->d_name);
1380 	if (rc) {
1381 		txAbort(tid, 0);
1382 		goto out3;
1383 	}
1384 
1385 	if ((rc = dtSearch(dir, &dname, &ino, &btstack, JFS_CREATE))) {
1386 		txAbort(tid, 0);
1387 		goto out3;
1388 	}
1389 
1390 	tblk = tid_to_tblock(tid);
1391 	tblk->xflag |= COMMIT_CREATE;
1392 	tblk->ino = ip->i_ino;
1393 	tblk->u.ixpxd = JFS_IP(ip)->ixpxd;
1394 
1395 	ino = ip->i_ino;
1396 	if ((rc = dtInsert(tid, dir, &dname, &ino, &btstack))) {
1397 		txAbort(tid, 0);
1398 		goto out3;
1399 	}
1400 
1401 	ip->i_op = &jfs_file_inode_operations;
1402 	jfs_ip->dev = new_encode_dev(rdev);
1403 	init_special_inode(ip, ip->i_mode, rdev);
1404 
1405 	mark_inode_dirty(ip);
1406 
1407 	dir->i_ctime = dir->i_mtime = CURRENT_TIME;
1408 
1409 	mark_inode_dirty(dir);
1410 
1411 	iplist[0] = dir;
1412 	iplist[1] = ip;
1413 	rc = txCommit(tid, 2, iplist, 0);
1414 
1415       out3:
1416 	txEnd(tid);
1417 	mutex_unlock(&JFS_IP(ip)->commit_mutex);
1418 	mutex_unlock(&JFS_IP(dir)->commit_mutex);
1419 	if (rc) {
1420 		free_ea_wmap(ip);
1421 		clear_nlink(ip);
1422 		unlock_new_inode(ip);
1423 		iput(ip);
1424 	} else {
1425 		unlock_new_inode(ip);
1426 		d_instantiate(dentry, ip);
1427 	}
1428 
1429       out1:
1430 	free_UCSname(&dname);
1431 
1432       out:
1433 	jfs_info("jfs_mknod: returning %d", rc);
1434 	return rc;
1435 }
1436 
1437 static struct dentry *jfs_lookup(struct inode *dip, struct dentry *dentry, unsigned int flags)
1438 {
1439 	struct btstack btstack;
1440 	ino_t inum;
1441 	struct inode *ip;
1442 	struct component_name key;
1443 	int rc;
1444 
1445 	jfs_info("jfs_lookup: name = %pd", dentry);
1446 
1447 	if ((rc = get_UCSname(&key, dentry)))
1448 		return ERR_PTR(rc);
1449 	rc = dtSearch(dip, &key, &inum, &btstack, JFS_LOOKUP);
1450 	free_UCSname(&key);
1451 	if (rc == -ENOENT) {
1452 		ip = NULL;
1453 	} else if (rc) {
1454 		jfs_err("jfs_lookup: dtSearch returned %d", rc);
1455 		ip = ERR_PTR(rc);
1456 	} else {
1457 		ip = jfs_iget(dip->i_sb, inum);
1458 		if (IS_ERR(ip))
1459 			jfs_err("jfs_lookup: iget failed on inum %d", (uint)inum);
1460 	}
1461 
1462 	return d_splice_alias(ip, dentry);
1463 }
1464 
1465 static struct inode *jfs_nfs_get_inode(struct super_block *sb,
1466 		u64 ino, u32 generation)
1467 {
1468 	struct inode *inode;
1469 
1470 	if (ino == 0)
1471 		return ERR_PTR(-ESTALE);
1472 	inode = jfs_iget(sb, ino);
1473 	if (IS_ERR(inode))
1474 		return ERR_CAST(inode);
1475 
1476 	if (generation && inode->i_generation != generation) {
1477 		iput(inode);
1478 		return ERR_PTR(-ESTALE);
1479 	}
1480 
1481 	return inode;
1482 }
1483 
1484 struct dentry *jfs_fh_to_dentry(struct super_block *sb, struct fid *fid,
1485 		int fh_len, int fh_type)
1486 {
1487 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1488 				    jfs_nfs_get_inode);
1489 }
1490 
1491 struct dentry *jfs_fh_to_parent(struct super_block *sb, struct fid *fid,
1492 		int fh_len, int fh_type)
1493 {
1494 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1495 				    jfs_nfs_get_inode);
1496 }
1497 
1498 struct dentry *jfs_get_parent(struct dentry *dentry)
1499 {
1500 	unsigned long parent_ino;
1501 
1502 	parent_ino =
1503 		le32_to_cpu(JFS_IP(dentry->d_inode)->i_dtroot.header.idotdot);
1504 
1505 	return d_obtain_alias(jfs_iget(dentry->d_inode->i_sb, parent_ino));
1506 }
1507 
1508 const struct inode_operations jfs_dir_inode_operations = {
1509 	.create		= jfs_create,
1510 	.lookup		= jfs_lookup,
1511 	.link		= jfs_link,
1512 	.unlink		= jfs_unlink,
1513 	.symlink	= jfs_symlink,
1514 	.mkdir		= jfs_mkdir,
1515 	.rmdir		= jfs_rmdir,
1516 	.mknod		= jfs_mknod,
1517 	.rename		= jfs_rename,
1518 	.setxattr	= jfs_setxattr,
1519 	.getxattr	= jfs_getxattr,
1520 	.listxattr	= jfs_listxattr,
1521 	.removexattr	= jfs_removexattr,
1522 	.setattr	= jfs_setattr,
1523 #ifdef CONFIG_JFS_POSIX_ACL
1524 	.get_acl	= jfs_get_acl,
1525 	.set_acl	= jfs_set_acl,
1526 #endif
1527 };
1528 
1529 const struct file_operations jfs_dir_operations = {
1530 	.read		= generic_read_dir,
1531 	.iterate	= jfs_readdir,
1532 	.fsync		= jfs_fsync,
1533 	.unlocked_ioctl = jfs_ioctl,
1534 #ifdef CONFIG_COMPAT
1535 	.compat_ioctl	= jfs_compat_ioctl,
1536 #endif
1537 	.llseek		= generic_file_llseek,
1538 };
1539 
1540 static int jfs_ci_hash(const struct dentry *dir, struct qstr *this)
1541 {
1542 	unsigned long hash;
1543 	int i;
1544 
1545 	hash = init_name_hash();
1546 	for (i=0; i < this->len; i++)
1547 		hash = partial_name_hash(tolower(this->name[i]), hash);
1548 	this->hash = end_name_hash(hash);
1549 
1550 	return 0;
1551 }
1552 
1553 static int jfs_ci_compare(const struct dentry *parent, const struct dentry *dentry,
1554 		unsigned int len, const char *str, const struct qstr *name)
1555 {
1556 	int i, result = 1;
1557 
1558 	if (len != name->len)
1559 		goto out;
1560 	for (i=0; i < len; i++) {
1561 		if (tolower(str[i]) != tolower(name->name[i]))
1562 			goto out;
1563 	}
1564 	result = 0;
1565 out:
1566 	return result;
1567 }
1568 
1569 static int jfs_ci_revalidate(struct dentry *dentry, unsigned int flags)
1570 {
1571 	/*
1572 	 * This is not negative dentry. Always valid.
1573 	 *
1574 	 * Note, rename() to existing directory entry will have ->d_inode,
1575 	 * and will use existing name which isn't specified name by user.
1576 	 *
1577 	 * We may be able to drop this positive dentry here. But dropping
1578 	 * positive dentry isn't good idea. So it's unsupported like
1579 	 * rename("filename", "FILENAME") for now.
1580 	 */
1581 	if (dentry->d_inode)
1582 		return 1;
1583 
1584 	/*
1585 	 * This may be nfsd (or something), anyway, we can't see the
1586 	 * intent of this. So, since this can be for creation, drop it.
1587 	 */
1588 	if (!flags)
1589 		return 0;
1590 
1591 	/*
1592 	 * Drop the negative dentry, in order to make sure to use the
1593 	 * case sensitive name which is specified by user if this is
1594 	 * for creation.
1595 	 */
1596 	if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
1597 		return 0;
1598 	return 1;
1599 }
1600 
1601 const struct dentry_operations jfs_ci_dentry_operations =
1602 {
1603 	.d_hash = jfs_ci_hash,
1604 	.d_compare = jfs_ci_compare,
1605 	.d_revalidate = jfs_ci_revalidate,
1606 };
1607