xref: /openbmc/linux/fs/ext4/namei.c (revision 22246614)
1 /*
2  *  linux/fs/ext4/namei.c
3  *
4  * Copyright (C) 1992, 1993, 1994, 1995
5  * Remy Card (card@masi.ibp.fr)
6  * Laboratoire MASI - Institut Blaise Pascal
7  * Universite Pierre et Marie Curie (Paris VI)
8  *
9  *  from
10  *
11  *  linux/fs/minix/namei.c
12  *
13  *  Copyright (C) 1991, 1992  Linus Torvalds
14  *
15  *  Big-endian to little-endian byte-swapping/bitmaps by
16  *        David S. Miller (davem@caip.rutgers.edu), 1995
17  *  Directory entry file type support and forward compatibility hooks
18  *	for B-tree directories by Theodore Ts'o (tytso@mit.edu), 1998
19  *  Hash Tree Directory indexing (c)
20  *	Daniel Phillips, 2001
21  *  Hash Tree Directory indexing porting
22  *	Christopher Li, 2002
23  *  Hash Tree Directory indexing cleanup
24  *	Theodore Ts'o, 2002
25  */
26 
27 #include <linux/fs.h>
28 #include <linux/pagemap.h>
29 #include <linux/jbd2.h>
30 #include <linux/time.h>
31 #include <linux/fcntl.h>
32 #include <linux/stat.h>
33 #include <linux/string.h>
34 #include <linux/quotaops.h>
35 #include <linux/buffer_head.h>
36 #include <linux/bio.h>
37 #include "ext4.h"
38 #include "ext4_jbd2.h"
39 
40 #include "namei.h"
41 #include "xattr.h"
42 #include "acl.h"
43 
44 /*
45  * define how far ahead to read directories while searching them.
46  */
47 #define NAMEI_RA_CHUNKS  2
48 #define NAMEI_RA_BLOCKS  4
49 #define NAMEI_RA_SIZE	     (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
50 #define NAMEI_RA_INDEX(c,b)  (((c) * NAMEI_RA_BLOCKS) + (b))
51 
52 static struct buffer_head *ext4_append(handle_t *handle,
53 					struct inode *inode,
54 					ext4_lblk_t *block, int *err)
55 {
56 	struct buffer_head *bh;
57 
58 	*block = inode->i_size >> inode->i_sb->s_blocksize_bits;
59 
60 	bh = ext4_bread(handle, inode, *block, 1, err);
61 	if (bh) {
62 		inode->i_size += inode->i_sb->s_blocksize;
63 		EXT4_I(inode)->i_disksize = inode->i_size;
64 		*err = ext4_journal_get_write_access(handle, bh);
65 		if (*err) {
66 			brelse(bh);
67 			bh = NULL;
68 		}
69 	}
70 	return bh;
71 }
72 
73 #ifndef assert
74 #define assert(test) J_ASSERT(test)
75 #endif
76 
77 #ifndef swap
78 #define swap(x, y) do { typeof(x) z = x; x = y; y = z; } while (0)
79 #endif
80 
81 #ifdef DX_DEBUG
82 #define dxtrace(command) command
83 #else
84 #define dxtrace(command)
85 #endif
86 
87 struct fake_dirent
88 {
89 	__le32 inode;
90 	__le16 rec_len;
91 	u8 name_len;
92 	u8 file_type;
93 };
94 
95 struct dx_countlimit
96 {
97 	__le16 limit;
98 	__le16 count;
99 };
100 
101 struct dx_entry
102 {
103 	__le32 hash;
104 	__le32 block;
105 };
106 
107 /*
108  * dx_root_info is laid out so that if it should somehow get overlaid by a
109  * dirent the two low bits of the hash version will be zero.  Therefore, the
110  * hash version mod 4 should never be 0.  Sincerely, the paranoia department.
111  */
112 
113 struct dx_root
114 {
115 	struct fake_dirent dot;
116 	char dot_name[4];
117 	struct fake_dirent dotdot;
118 	char dotdot_name[4];
119 	struct dx_root_info
120 	{
121 		__le32 reserved_zero;
122 		u8 hash_version;
123 		u8 info_length; /* 8 */
124 		u8 indirect_levels;
125 		u8 unused_flags;
126 	}
127 	info;
128 	struct dx_entry	entries[0];
129 };
130 
131 struct dx_node
132 {
133 	struct fake_dirent fake;
134 	struct dx_entry	entries[0];
135 };
136 
137 
138 struct dx_frame
139 {
140 	struct buffer_head *bh;
141 	struct dx_entry *entries;
142 	struct dx_entry *at;
143 };
144 
145 struct dx_map_entry
146 {
147 	u32 hash;
148 	u16 offs;
149 	u16 size;
150 };
151 
152 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
153 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
154 static inline unsigned dx_get_hash (struct dx_entry *entry);
155 static void dx_set_hash (struct dx_entry *entry, unsigned value);
156 static unsigned dx_get_count (struct dx_entry *entries);
157 static unsigned dx_get_limit (struct dx_entry *entries);
158 static void dx_set_count (struct dx_entry *entries, unsigned value);
159 static void dx_set_limit (struct dx_entry *entries, unsigned value);
160 static unsigned dx_root_limit (struct inode *dir, unsigned infosize);
161 static unsigned dx_node_limit (struct inode *dir);
162 static struct dx_frame *dx_probe(struct dentry *dentry,
163 				 struct inode *dir,
164 				 struct dx_hash_info *hinfo,
165 				 struct dx_frame *frame,
166 				 int *err);
167 static void dx_release (struct dx_frame *frames);
168 static int dx_make_map (struct ext4_dir_entry_2 *de, int size,
169 			struct dx_hash_info *hinfo, struct dx_map_entry map[]);
170 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
171 static struct ext4_dir_entry_2 *dx_move_dirents (char *from, char *to,
172 		struct dx_map_entry *offsets, int count);
173 static struct ext4_dir_entry_2* dx_pack_dirents (char *base, int size);
174 static void dx_insert_block(struct dx_frame *frame,
175 					u32 hash, ext4_lblk_t block);
176 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
177 				 struct dx_frame *frame,
178 				 struct dx_frame *frames,
179 				 __u32 *start_hash);
180 static struct buffer_head * ext4_dx_find_entry(struct dentry *dentry,
181 		       struct ext4_dir_entry_2 **res_dir, int *err);
182 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
183 			     struct inode *inode);
184 
185 /*
186  * Future: use high four bits of block for coalesce-on-delete flags
187  * Mask them off for now.
188  */
189 
190 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
191 {
192 	return le32_to_cpu(entry->block) & 0x00ffffff;
193 }
194 
195 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
196 {
197 	entry->block = cpu_to_le32(value);
198 }
199 
200 static inline unsigned dx_get_hash (struct dx_entry *entry)
201 {
202 	return le32_to_cpu(entry->hash);
203 }
204 
205 static inline void dx_set_hash (struct dx_entry *entry, unsigned value)
206 {
207 	entry->hash = cpu_to_le32(value);
208 }
209 
210 static inline unsigned dx_get_count (struct dx_entry *entries)
211 {
212 	return le16_to_cpu(((struct dx_countlimit *) entries)->count);
213 }
214 
215 static inline unsigned dx_get_limit (struct dx_entry *entries)
216 {
217 	return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
218 }
219 
220 static inline void dx_set_count (struct dx_entry *entries, unsigned value)
221 {
222 	((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
223 }
224 
225 static inline void dx_set_limit (struct dx_entry *entries, unsigned value)
226 {
227 	((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
228 }
229 
230 static inline unsigned dx_root_limit (struct inode *dir, unsigned infosize)
231 {
232 	unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
233 		EXT4_DIR_REC_LEN(2) - infosize;
234 	return 0? 20: entry_space / sizeof(struct dx_entry);
235 }
236 
237 static inline unsigned dx_node_limit (struct inode *dir)
238 {
239 	unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
240 	return 0? 22: entry_space / sizeof(struct dx_entry);
241 }
242 
243 /*
244  * Debug
245  */
246 #ifdef DX_DEBUG
247 static void dx_show_index (char * label, struct dx_entry *entries)
248 {
249 	int i, n = dx_get_count (entries);
250 	printk("%s index ", label);
251 	for (i = 0; i < n; i++) {
252 		printk("%x->%lu ", i? dx_get_hash(entries + i) :
253 				0, (unsigned long)dx_get_block(entries + i));
254 	}
255 	printk("\n");
256 }
257 
258 struct stats
259 {
260 	unsigned names;
261 	unsigned space;
262 	unsigned bcount;
263 };
264 
265 static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_entry_2 *de,
266 				 int size, int show_names)
267 {
268 	unsigned names = 0, space = 0;
269 	char *base = (char *) de;
270 	struct dx_hash_info h = *hinfo;
271 
272 	printk("names: ");
273 	while ((char *) de < base + size)
274 	{
275 		if (de->inode)
276 		{
277 			if (show_names)
278 			{
279 				int len = de->name_len;
280 				char *name = de->name;
281 				while (len--) printk("%c", *name++);
282 				ext4fs_dirhash(de->name, de->name_len, &h);
283 				printk(":%x.%u ", h.hash,
284 				       ((char *) de - base));
285 			}
286 			space += EXT4_DIR_REC_LEN(de->name_len);
287 			names++;
288 		}
289 		de = ext4_next_entry(de);
290 	}
291 	printk("(%i)\n", names);
292 	return (struct stats) { names, space, 1 };
293 }
294 
295 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
296 			     struct dx_entry *entries, int levels)
297 {
298 	unsigned blocksize = dir->i_sb->s_blocksize;
299 	unsigned count = dx_get_count (entries), names = 0, space = 0, i;
300 	unsigned bcount = 0;
301 	struct buffer_head *bh;
302 	int err;
303 	printk("%i indexed blocks...\n", count);
304 	for (i = 0; i < count; i++, entries++)
305 	{
306 		ext4_lblk_t block = dx_get_block(entries);
307 		ext4_lblk_t hash  = i ? dx_get_hash(entries): 0;
308 		u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
309 		struct stats stats;
310 		printk("%s%3u:%03u hash %8x/%8x ",levels?"":"   ", i, block, hash, range);
311 		if (!(bh = ext4_bread (NULL,dir, block, 0,&err))) continue;
312 		stats = levels?
313 		   dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
314 		   dx_show_leaf(hinfo, (struct ext4_dir_entry_2 *) bh->b_data, blocksize, 0);
315 		names += stats.names;
316 		space += stats.space;
317 		bcount += stats.bcount;
318 		brelse (bh);
319 	}
320 	if (bcount)
321 		printk("%snames %u, fullness %u (%u%%)\n", levels?"":"   ",
322 			names, space/bcount,(space/bcount)*100/blocksize);
323 	return (struct stats) { names, space, bcount};
324 }
325 #endif /* DX_DEBUG */
326 
327 /*
328  * Probe for a directory leaf block to search.
329  *
330  * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
331  * error in the directory index, and the caller should fall back to
332  * searching the directory normally.  The callers of dx_probe **MUST**
333  * check for this error code, and make sure it never gets reflected
334  * back to userspace.
335  */
336 static struct dx_frame *
337 dx_probe(struct dentry *dentry, struct inode *dir,
338 	 struct dx_hash_info *hinfo, struct dx_frame *frame_in, int *err)
339 {
340 	unsigned count, indirect;
341 	struct dx_entry *at, *entries, *p, *q, *m;
342 	struct dx_root *root;
343 	struct buffer_head *bh;
344 	struct dx_frame *frame = frame_in;
345 	u32 hash;
346 
347 	frame->bh = NULL;
348 	if (dentry)
349 		dir = dentry->d_parent->d_inode;
350 	if (!(bh = ext4_bread (NULL,dir, 0, 0, err)))
351 		goto fail;
352 	root = (struct dx_root *) bh->b_data;
353 	if (root->info.hash_version != DX_HASH_TEA &&
354 	    root->info.hash_version != DX_HASH_HALF_MD4 &&
355 	    root->info.hash_version != DX_HASH_LEGACY) {
356 		ext4_warning(dir->i_sb, __func__,
357 			     "Unrecognised inode hash code %d",
358 			     root->info.hash_version);
359 		brelse(bh);
360 		*err = ERR_BAD_DX_DIR;
361 		goto fail;
362 	}
363 	hinfo->hash_version = root->info.hash_version;
364 	hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
365 	if (dentry)
366 		ext4fs_dirhash(dentry->d_name.name, dentry->d_name.len, hinfo);
367 	hash = hinfo->hash;
368 
369 	if (root->info.unused_flags & 1) {
370 		ext4_warning(dir->i_sb, __func__,
371 			     "Unimplemented inode hash flags: %#06x",
372 			     root->info.unused_flags);
373 		brelse(bh);
374 		*err = ERR_BAD_DX_DIR;
375 		goto fail;
376 	}
377 
378 	if ((indirect = root->info.indirect_levels) > 1) {
379 		ext4_warning(dir->i_sb, __func__,
380 			     "Unimplemented inode hash depth: %#06x",
381 			     root->info.indirect_levels);
382 		brelse(bh);
383 		*err = ERR_BAD_DX_DIR;
384 		goto fail;
385 	}
386 
387 	entries = (struct dx_entry *) (((char *)&root->info) +
388 				       root->info.info_length);
389 
390 	if (dx_get_limit(entries) != dx_root_limit(dir,
391 						   root->info.info_length)) {
392 		ext4_warning(dir->i_sb, __func__,
393 			     "dx entry: limit != root limit");
394 		brelse(bh);
395 		*err = ERR_BAD_DX_DIR;
396 		goto fail;
397 	}
398 
399 	dxtrace (printk("Look up %x", hash));
400 	while (1)
401 	{
402 		count = dx_get_count(entries);
403 		if (!count || count > dx_get_limit(entries)) {
404 			ext4_warning(dir->i_sb, __func__,
405 				     "dx entry: no count or count > limit");
406 			brelse(bh);
407 			*err = ERR_BAD_DX_DIR;
408 			goto fail2;
409 		}
410 
411 		p = entries + 1;
412 		q = entries + count - 1;
413 		while (p <= q)
414 		{
415 			m = p + (q - p)/2;
416 			dxtrace(printk("."));
417 			if (dx_get_hash(m) > hash)
418 				q = m - 1;
419 			else
420 				p = m + 1;
421 		}
422 
423 		if (0) // linear search cross check
424 		{
425 			unsigned n = count - 1;
426 			at = entries;
427 			while (n--)
428 			{
429 				dxtrace(printk(","));
430 				if (dx_get_hash(++at) > hash)
431 				{
432 					at--;
433 					break;
434 				}
435 			}
436 			assert (at == p - 1);
437 		}
438 
439 		at = p - 1;
440 		dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at)));
441 		frame->bh = bh;
442 		frame->entries = entries;
443 		frame->at = at;
444 		if (!indirect--) return frame;
445 		if (!(bh = ext4_bread (NULL,dir, dx_get_block(at), 0, err)))
446 			goto fail2;
447 		at = entries = ((struct dx_node *) bh->b_data)->entries;
448 		if (dx_get_limit(entries) != dx_node_limit (dir)) {
449 			ext4_warning(dir->i_sb, __func__,
450 				     "dx entry: limit != node limit");
451 			brelse(bh);
452 			*err = ERR_BAD_DX_DIR;
453 			goto fail2;
454 		}
455 		frame++;
456 		frame->bh = NULL;
457 	}
458 fail2:
459 	while (frame >= frame_in) {
460 		brelse(frame->bh);
461 		frame--;
462 	}
463 fail:
464 	if (*err == ERR_BAD_DX_DIR)
465 		ext4_warning(dir->i_sb, __func__,
466 			     "Corrupt dir inode %ld, running e2fsck is "
467 			     "recommended.", dir->i_ino);
468 	return NULL;
469 }
470 
471 static void dx_release (struct dx_frame *frames)
472 {
473 	if (frames[0].bh == NULL)
474 		return;
475 
476 	if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
477 		brelse(frames[1].bh);
478 	brelse(frames[0].bh);
479 }
480 
481 /*
482  * This function increments the frame pointer to search the next leaf
483  * block, and reads in the necessary intervening nodes if the search
484  * should be necessary.  Whether or not the search is necessary is
485  * controlled by the hash parameter.  If the hash value is even, then
486  * the search is only continued if the next block starts with that
487  * hash value.  This is used if we are searching for a specific file.
488  *
489  * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
490  *
491  * This function returns 1 if the caller should continue to search,
492  * or 0 if it should not.  If there is an error reading one of the
493  * index blocks, it will a negative error code.
494  *
495  * If start_hash is non-null, it will be filled in with the starting
496  * hash of the next page.
497  */
498 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
499 				 struct dx_frame *frame,
500 				 struct dx_frame *frames,
501 				 __u32 *start_hash)
502 {
503 	struct dx_frame *p;
504 	struct buffer_head *bh;
505 	int err, num_frames = 0;
506 	__u32 bhash;
507 
508 	p = frame;
509 	/*
510 	 * Find the next leaf page by incrementing the frame pointer.
511 	 * If we run out of entries in the interior node, loop around and
512 	 * increment pointer in the parent node.  When we break out of
513 	 * this loop, num_frames indicates the number of interior
514 	 * nodes need to be read.
515 	 */
516 	while (1) {
517 		if (++(p->at) < p->entries + dx_get_count(p->entries))
518 			break;
519 		if (p == frames)
520 			return 0;
521 		num_frames++;
522 		p--;
523 	}
524 
525 	/*
526 	 * If the hash is 1, then continue only if the next page has a
527 	 * continuation hash of any value.  This is used for readdir
528 	 * handling.  Otherwise, check to see if the hash matches the
529 	 * desired contiuation hash.  If it doesn't, return since
530 	 * there's no point to read in the successive index pages.
531 	 */
532 	bhash = dx_get_hash(p->at);
533 	if (start_hash)
534 		*start_hash = bhash;
535 	if ((hash & 1) == 0) {
536 		if ((bhash & ~1) != hash)
537 			return 0;
538 	}
539 	/*
540 	 * If the hash is HASH_NB_ALWAYS, we always go to the next
541 	 * block so no check is necessary
542 	 */
543 	while (num_frames--) {
544 		if (!(bh = ext4_bread(NULL, dir, dx_get_block(p->at),
545 				      0, &err)))
546 			return err; /* Failure */
547 		p++;
548 		brelse (p->bh);
549 		p->bh = bh;
550 		p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
551 	}
552 	return 1;
553 }
554 
555 
556 /*
557  * p is at least 6 bytes before the end of page
558  */
559 static inline struct ext4_dir_entry_2 *ext4_next_entry(struct ext4_dir_entry_2 *p)
560 {
561 	return (struct ext4_dir_entry_2 *)((char *)p +
562 		ext4_rec_len_from_disk(p->rec_len));
563 }
564 
565 /*
566  * This function fills a red-black tree with information from a
567  * directory block.  It returns the number directory entries loaded
568  * into the tree.  If there is an error it is returned in err.
569  */
570 static int htree_dirblock_to_tree(struct file *dir_file,
571 				  struct inode *dir, ext4_lblk_t block,
572 				  struct dx_hash_info *hinfo,
573 				  __u32 start_hash, __u32 start_minor_hash)
574 {
575 	struct buffer_head *bh;
576 	struct ext4_dir_entry_2 *de, *top;
577 	int err, count = 0;
578 
579 	dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
580 							(unsigned long)block));
581 	if (!(bh = ext4_bread (NULL, dir, block, 0, &err)))
582 		return err;
583 
584 	de = (struct ext4_dir_entry_2 *) bh->b_data;
585 	top = (struct ext4_dir_entry_2 *) ((char *) de +
586 					   dir->i_sb->s_blocksize -
587 					   EXT4_DIR_REC_LEN(0));
588 	for (; de < top; de = ext4_next_entry(de)) {
589 		if (!ext4_check_dir_entry("htree_dirblock_to_tree", dir, de, bh,
590 					(block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
591 						+((char *)de - bh->b_data))) {
592 			/* On error, skip the f_pos to the next block. */
593 			dir_file->f_pos = (dir_file->f_pos |
594 					(dir->i_sb->s_blocksize - 1)) + 1;
595 			brelse (bh);
596 			return count;
597 		}
598 		ext4fs_dirhash(de->name, de->name_len, hinfo);
599 		if ((hinfo->hash < start_hash) ||
600 		    ((hinfo->hash == start_hash) &&
601 		     (hinfo->minor_hash < start_minor_hash)))
602 			continue;
603 		if (de->inode == 0)
604 			continue;
605 		if ((err = ext4_htree_store_dirent(dir_file,
606 				   hinfo->hash, hinfo->minor_hash, de)) != 0) {
607 			brelse(bh);
608 			return err;
609 		}
610 		count++;
611 	}
612 	brelse(bh);
613 	return count;
614 }
615 
616 
617 /*
618  * This function fills a red-black tree with information from a
619  * directory.  We start scanning the directory in hash order, starting
620  * at start_hash and start_minor_hash.
621  *
622  * This function returns the number of entries inserted into the tree,
623  * or a negative error code.
624  */
625 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
626 			 __u32 start_minor_hash, __u32 *next_hash)
627 {
628 	struct dx_hash_info hinfo;
629 	struct ext4_dir_entry_2 *de;
630 	struct dx_frame frames[2], *frame;
631 	struct inode *dir;
632 	ext4_lblk_t block;
633 	int count = 0;
634 	int ret, err;
635 	__u32 hashval;
636 
637 	dxtrace(printk("In htree_fill_tree, start hash: %x:%x\n", start_hash,
638 		       start_minor_hash));
639 	dir = dir_file->f_path.dentry->d_inode;
640 	if (!(EXT4_I(dir)->i_flags & EXT4_INDEX_FL)) {
641 		hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
642 		hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
643 		count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
644 					       start_hash, start_minor_hash);
645 		*next_hash = ~0;
646 		return count;
647 	}
648 	hinfo.hash = start_hash;
649 	hinfo.minor_hash = 0;
650 	frame = dx_probe(NULL, dir_file->f_path.dentry->d_inode, &hinfo, frames, &err);
651 	if (!frame)
652 		return err;
653 
654 	/* Add '.' and '..' from the htree header */
655 	if (!start_hash && !start_minor_hash) {
656 		de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
657 		if ((err = ext4_htree_store_dirent(dir_file, 0, 0, de)) != 0)
658 			goto errout;
659 		count++;
660 	}
661 	if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
662 		de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
663 		de = ext4_next_entry(de);
664 		if ((err = ext4_htree_store_dirent(dir_file, 2, 0, de)) != 0)
665 			goto errout;
666 		count++;
667 	}
668 
669 	while (1) {
670 		block = dx_get_block(frame->at);
671 		ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
672 					     start_hash, start_minor_hash);
673 		if (ret < 0) {
674 			err = ret;
675 			goto errout;
676 		}
677 		count += ret;
678 		hashval = ~0;
679 		ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
680 					    frame, frames, &hashval);
681 		*next_hash = hashval;
682 		if (ret < 0) {
683 			err = ret;
684 			goto errout;
685 		}
686 		/*
687 		 * Stop if:  (a) there are no more entries, or
688 		 * (b) we have inserted at least one entry and the
689 		 * next hash value is not a continuation
690 		 */
691 		if ((ret == 0) ||
692 		    (count && ((hashval & 1) == 0)))
693 			break;
694 	}
695 	dx_release(frames);
696 	dxtrace(printk("Fill tree: returned %d entries, next hash: %x\n",
697 		       count, *next_hash));
698 	return count;
699 errout:
700 	dx_release(frames);
701 	return (err);
702 }
703 
704 
705 /*
706  * Directory block splitting, compacting
707  */
708 
709 /*
710  * Create map of hash values, offsets, and sizes, stored at end of block.
711  * Returns number of entries mapped.
712  */
713 static int dx_make_map (struct ext4_dir_entry_2 *de, int size,
714 			struct dx_hash_info *hinfo, struct dx_map_entry *map_tail)
715 {
716 	int count = 0;
717 	char *base = (char *) de;
718 	struct dx_hash_info h = *hinfo;
719 
720 	while ((char *) de < base + size)
721 	{
722 		if (de->name_len && de->inode) {
723 			ext4fs_dirhash(de->name, de->name_len, &h);
724 			map_tail--;
725 			map_tail->hash = h.hash;
726 			map_tail->offs = (u16) ((char *) de - base);
727 			map_tail->size = le16_to_cpu(de->rec_len);
728 			count++;
729 			cond_resched();
730 		}
731 		/* XXX: do we need to check rec_len == 0 case? -Chris */
732 		de = ext4_next_entry(de);
733 	}
734 	return count;
735 }
736 
737 /* Sort map by hash value */
738 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
739 {
740 	struct dx_map_entry *p, *q, *top = map + count - 1;
741 	int more;
742 	/* Combsort until bubble sort doesn't suck */
743 	while (count > 2) {
744 		count = count*10/13;
745 		if (count - 9 < 2) /* 9, 10 -> 11 */
746 			count = 11;
747 		for (p = top, q = p - count; q >= map; p--, q--)
748 			if (p->hash < q->hash)
749 				swap(*p, *q);
750 	}
751 	/* Garden variety bubble sort */
752 	do {
753 		more = 0;
754 		q = top;
755 		while (q-- > map) {
756 			if (q[1].hash >= q[0].hash)
757 				continue;
758 			swap(*(q+1), *q);
759 			more = 1;
760 		}
761 	} while(more);
762 }
763 
764 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
765 {
766 	struct dx_entry *entries = frame->entries;
767 	struct dx_entry *old = frame->at, *new = old + 1;
768 	int count = dx_get_count(entries);
769 
770 	assert(count < dx_get_limit(entries));
771 	assert(old < entries + count);
772 	memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
773 	dx_set_hash(new, hash);
774 	dx_set_block(new, block);
775 	dx_set_count(entries, count + 1);
776 }
777 
778 static void ext4_update_dx_flag(struct inode *inode)
779 {
780 	if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
781 				     EXT4_FEATURE_COMPAT_DIR_INDEX))
782 		EXT4_I(inode)->i_flags &= ~EXT4_INDEX_FL;
783 }
784 
785 /*
786  * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
787  *
788  * `len <= EXT4_NAME_LEN' is guaranteed by caller.
789  * `de != NULL' is guaranteed by caller.
790  */
791 static inline int ext4_match (int len, const char * const name,
792 			      struct ext4_dir_entry_2 * de)
793 {
794 	if (len != de->name_len)
795 		return 0;
796 	if (!de->inode)
797 		return 0;
798 	return !memcmp(name, de->name, len);
799 }
800 
801 /*
802  * Returns 0 if not found, -1 on failure, and 1 on success
803  */
804 static inline int search_dirblock(struct buffer_head * bh,
805 				  struct inode *dir,
806 				  struct dentry *dentry,
807 				  unsigned long offset,
808 				  struct ext4_dir_entry_2 ** res_dir)
809 {
810 	struct ext4_dir_entry_2 * de;
811 	char * dlimit;
812 	int de_len;
813 	const char *name = dentry->d_name.name;
814 	int namelen = dentry->d_name.len;
815 
816 	de = (struct ext4_dir_entry_2 *) bh->b_data;
817 	dlimit = bh->b_data + dir->i_sb->s_blocksize;
818 	while ((char *) de < dlimit) {
819 		/* this code is executed quadratically often */
820 		/* do minimal checking `by hand' */
821 
822 		if ((char *) de + namelen <= dlimit &&
823 		    ext4_match (namelen, name, de)) {
824 			/* found a match - just to be sure, do a full check */
825 			if (!ext4_check_dir_entry("ext4_find_entry",
826 						  dir, de, bh, offset))
827 				return -1;
828 			*res_dir = de;
829 			return 1;
830 		}
831 		/* prevent looping on a bad block */
832 		de_len = ext4_rec_len_from_disk(de->rec_len);
833 		if (de_len <= 0)
834 			return -1;
835 		offset += de_len;
836 		de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
837 	}
838 	return 0;
839 }
840 
841 
842 /*
843  *	ext4_find_entry()
844  *
845  * finds an entry in the specified directory with the wanted name. It
846  * returns the cache buffer in which the entry was found, and the entry
847  * itself (as a parameter - res_dir). It does NOT read the inode of the
848  * entry - you'll have to do that yourself if you want to.
849  *
850  * The returned buffer_head has ->b_count elevated.  The caller is expected
851  * to brelse() it when appropriate.
852  */
853 static struct buffer_head * ext4_find_entry (struct dentry *dentry,
854 					struct ext4_dir_entry_2 ** res_dir)
855 {
856 	struct super_block * sb;
857 	struct buffer_head * bh_use[NAMEI_RA_SIZE];
858 	struct buffer_head * bh, *ret = NULL;
859 	ext4_lblk_t start, block, b;
860 	int ra_max = 0;		/* Number of bh's in the readahead
861 				   buffer, bh_use[] */
862 	int ra_ptr = 0;		/* Current index into readahead
863 				   buffer */
864 	int num = 0;
865 	ext4_lblk_t  nblocks;
866 	int i, err;
867 	struct inode *dir = dentry->d_parent->d_inode;
868 	int namelen;
869 
870 	*res_dir = NULL;
871 	sb = dir->i_sb;
872 	namelen = dentry->d_name.len;
873 	if (namelen > EXT4_NAME_LEN)
874 		return NULL;
875 	if (is_dx(dir)) {
876 		bh = ext4_dx_find_entry(dentry, res_dir, &err);
877 		/*
878 		 * On success, or if the error was file not found,
879 		 * return.  Otherwise, fall back to doing a search the
880 		 * old fashioned way.
881 		 */
882 		if (bh || (err != ERR_BAD_DX_DIR))
883 			return bh;
884 		dxtrace(printk("ext4_find_entry: dx failed, falling back\n"));
885 	}
886 	nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
887 	start = EXT4_I(dir)->i_dir_start_lookup;
888 	if (start >= nblocks)
889 		start = 0;
890 	block = start;
891 restart:
892 	do {
893 		/*
894 		 * We deal with the read-ahead logic here.
895 		 */
896 		if (ra_ptr >= ra_max) {
897 			/* Refill the readahead buffer */
898 			ra_ptr = 0;
899 			b = block;
900 			for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
901 				/*
902 				 * Terminate if we reach the end of the
903 				 * directory and must wrap, or if our
904 				 * search has finished at this block.
905 				 */
906 				if (b >= nblocks || (num && block == start)) {
907 					bh_use[ra_max] = NULL;
908 					break;
909 				}
910 				num++;
911 				bh = ext4_getblk(NULL, dir, b++, 0, &err);
912 				bh_use[ra_max] = bh;
913 				if (bh)
914 					ll_rw_block(READ_META, 1, &bh);
915 			}
916 		}
917 		if ((bh = bh_use[ra_ptr++]) == NULL)
918 			goto next;
919 		wait_on_buffer(bh);
920 		if (!buffer_uptodate(bh)) {
921 			/* read error, skip block & hope for the best */
922 			ext4_error(sb, __func__, "reading directory #%lu "
923 				   "offset %lu", dir->i_ino,
924 				   (unsigned long)block);
925 			brelse(bh);
926 			goto next;
927 		}
928 		i = search_dirblock(bh, dir, dentry,
929 			    block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
930 		if (i == 1) {
931 			EXT4_I(dir)->i_dir_start_lookup = block;
932 			ret = bh;
933 			goto cleanup_and_exit;
934 		} else {
935 			brelse(bh);
936 			if (i < 0)
937 				goto cleanup_and_exit;
938 		}
939 	next:
940 		if (++block >= nblocks)
941 			block = 0;
942 	} while (block != start);
943 
944 	/*
945 	 * If the directory has grown while we were searching, then
946 	 * search the last part of the directory before giving up.
947 	 */
948 	block = nblocks;
949 	nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
950 	if (block < nblocks) {
951 		start = 0;
952 		goto restart;
953 	}
954 
955 cleanup_and_exit:
956 	/* Clean up the read-ahead blocks */
957 	for (; ra_ptr < ra_max; ra_ptr++)
958 		brelse (bh_use[ra_ptr]);
959 	return ret;
960 }
961 
962 static struct buffer_head * ext4_dx_find_entry(struct dentry *dentry,
963 		       struct ext4_dir_entry_2 **res_dir, int *err)
964 {
965 	struct super_block * sb;
966 	struct dx_hash_info	hinfo;
967 	u32 hash;
968 	struct dx_frame frames[2], *frame;
969 	struct ext4_dir_entry_2 *de, *top;
970 	struct buffer_head *bh;
971 	ext4_lblk_t block;
972 	int retval;
973 	int namelen = dentry->d_name.len;
974 	const u8 *name = dentry->d_name.name;
975 	struct inode *dir = dentry->d_parent->d_inode;
976 
977 	sb = dir->i_sb;
978 	/* NFS may look up ".." - look at dx_root directory block */
979 	if (namelen > 2 || name[0] != '.'||(name[1] != '.' && name[1] != '\0')){
980 		if (!(frame = dx_probe(dentry, NULL, &hinfo, frames, err)))
981 			return NULL;
982 	} else {
983 		frame = frames;
984 		frame->bh = NULL;			/* for dx_release() */
985 		frame->at = (struct dx_entry *)frames;	/* hack for zero entry*/
986 		dx_set_block(frame->at, 0);		/* dx_root block is 0 */
987 	}
988 	hash = hinfo.hash;
989 	do {
990 		block = dx_get_block(frame->at);
991 		if (!(bh = ext4_bread (NULL,dir, block, 0, err)))
992 			goto errout;
993 		de = (struct ext4_dir_entry_2 *) bh->b_data;
994 		top = (struct ext4_dir_entry_2 *) ((char *) de + sb->s_blocksize -
995 				       EXT4_DIR_REC_LEN(0));
996 		for (; de < top; de = ext4_next_entry(de))
997 		if (ext4_match (namelen, name, de)) {
998 			if (!ext4_check_dir_entry("ext4_find_entry",
999 						  dir, de, bh,
1000 				  (block<<EXT4_BLOCK_SIZE_BITS(sb))
1001 					  +((char *)de - bh->b_data))) {
1002 				brelse (bh);
1003 				*err = ERR_BAD_DX_DIR;
1004 				goto errout;
1005 			}
1006 			*res_dir = de;
1007 			dx_release (frames);
1008 			return bh;
1009 		}
1010 		brelse (bh);
1011 		/* Check to see if we should continue to search */
1012 		retval = ext4_htree_next_block(dir, hash, frame,
1013 					       frames, NULL);
1014 		if (retval < 0) {
1015 			ext4_warning(sb, __func__,
1016 			     "error reading index page in directory #%lu",
1017 			     dir->i_ino);
1018 			*err = retval;
1019 			goto errout;
1020 		}
1021 	} while (retval == 1);
1022 
1023 	*err = -ENOENT;
1024 errout:
1025 	dxtrace(printk("%s not found\n", name));
1026 	dx_release (frames);
1027 	return NULL;
1028 }
1029 
1030 static struct dentry *ext4_lookup(struct inode * dir, struct dentry *dentry, struct nameidata *nd)
1031 {
1032 	struct inode * inode;
1033 	struct ext4_dir_entry_2 * de;
1034 	struct buffer_head * bh;
1035 
1036 	if (dentry->d_name.len > EXT4_NAME_LEN)
1037 		return ERR_PTR(-ENAMETOOLONG);
1038 
1039 	bh = ext4_find_entry(dentry, &de);
1040 	inode = NULL;
1041 	if (bh) {
1042 		unsigned long ino = le32_to_cpu(de->inode);
1043 		brelse (bh);
1044 		if (!ext4_valid_inum(dir->i_sb, ino)) {
1045 			ext4_error(dir->i_sb, "ext4_lookup",
1046 				   "bad inode number: %lu", ino);
1047 			return ERR_PTR(-EIO);
1048 		}
1049 		inode = ext4_iget(dir->i_sb, ino);
1050 		if (IS_ERR(inode))
1051 			return ERR_CAST(inode);
1052 	}
1053 	return d_splice_alias(inode, dentry);
1054 }
1055 
1056 
1057 struct dentry *ext4_get_parent(struct dentry *child)
1058 {
1059 	unsigned long ino;
1060 	struct dentry *parent;
1061 	struct inode *inode;
1062 	struct dentry dotdot;
1063 	struct ext4_dir_entry_2 * de;
1064 	struct buffer_head *bh;
1065 
1066 	dotdot.d_name.name = "..";
1067 	dotdot.d_name.len = 2;
1068 	dotdot.d_parent = child; /* confusing, isn't it! */
1069 
1070 	bh = ext4_find_entry(&dotdot, &de);
1071 	inode = NULL;
1072 	if (!bh)
1073 		return ERR_PTR(-ENOENT);
1074 	ino = le32_to_cpu(de->inode);
1075 	brelse(bh);
1076 
1077 	if (!ext4_valid_inum(child->d_inode->i_sb, ino)) {
1078 		ext4_error(child->d_inode->i_sb, "ext4_get_parent",
1079 			   "bad inode number: %lu", ino);
1080 		return ERR_PTR(-EIO);
1081 	}
1082 
1083 	inode = ext4_iget(child->d_inode->i_sb, ino);
1084 	if (IS_ERR(inode))
1085 		return ERR_CAST(inode);
1086 
1087 	parent = d_alloc_anon(inode);
1088 	if (!parent) {
1089 		iput(inode);
1090 		parent = ERR_PTR(-ENOMEM);
1091 	}
1092 	return parent;
1093 }
1094 
1095 #define S_SHIFT 12
1096 static unsigned char ext4_type_by_mode[S_IFMT >> S_SHIFT] = {
1097 	[S_IFREG >> S_SHIFT]	= EXT4_FT_REG_FILE,
1098 	[S_IFDIR >> S_SHIFT]	= EXT4_FT_DIR,
1099 	[S_IFCHR >> S_SHIFT]	= EXT4_FT_CHRDEV,
1100 	[S_IFBLK >> S_SHIFT]	= EXT4_FT_BLKDEV,
1101 	[S_IFIFO >> S_SHIFT]	= EXT4_FT_FIFO,
1102 	[S_IFSOCK >> S_SHIFT]	= EXT4_FT_SOCK,
1103 	[S_IFLNK >> S_SHIFT]	= EXT4_FT_SYMLINK,
1104 };
1105 
1106 static inline void ext4_set_de_type(struct super_block *sb,
1107 				struct ext4_dir_entry_2 *de,
1108 				umode_t mode) {
1109 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE))
1110 		de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
1111 }
1112 
1113 /*
1114  * Move count entries from end of map between two memory locations.
1115  * Returns pointer to last entry moved.
1116  */
1117 static struct ext4_dir_entry_2 *
1118 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count)
1119 {
1120 	unsigned rec_len = 0;
1121 
1122 	while (count--) {
1123 		struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *) (from + map->offs);
1124 		rec_len = EXT4_DIR_REC_LEN(de->name_len);
1125 		memcpy (to, de, rec_len);
1126 		((struct ext4_dir_entry_2 *) to)->rec_len =
1127 				ext4_rec_len_to_disk(rec_len);
1128 		de->inode = 0;
1129 		map++;
1130 		to += rec_len;
1131 	}
1132 	return (struct ext4_dir_entry_2 *) (to - rec_len);
1133 }
1134 
1135 /*
1136  * Compact each dir entry in the range to the minimal rec_len.
1137  * Returns pointer to last entry in range.
1138  */
1139 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, int size)
1140 {
1141 	struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1142 	unsigned rec_len = 0;
1143 
1144 	prev = to = de;
1145 	while ((char*)de < base + size) {
1146 		next = ext4_next_entry(de);
1147 		if (de->inode && de->name_len) {
1148 			rec_len = EXT4_DIR_REC_LEN(de->name_len);
1149 			if (de > to)
1150 				memmove(to, de, rec_len);
1151 			to->rec_len = ext4_rec_len_to_disk(rec_len);
1152 			prev = to;
1153 			to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1154 		}
1155 		de = next;
1156 	}
1157 	return prev;
1158 }
1159 
1160 /*
1161  * Split a full leaf block to make room for a new dir entry.
1162  * Allocate a new block, and move entries so that they are approx. equally full.
1163  * Returns pointer to de in block into which the new entry will be inserted.
1164  */
1165 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1166 			struct buffer_head **bh,struct dx_frame *frame,
1167 			struct dx_hash_info *hinfo, int *error)
1168 {
1169 	unsigned blocksize = dir->i_sb->s_blocksize;
1170 	unsigned count, continued;
1171 	struct buffer_head *bh2;
1172 	ext4_lblk_t newblock;
1173 	u32 hash2;
1174 	struct dx_map_entry *map;
1175 	char *data1 = (*bh)->b_data, *data2;
1176 	unsigned split, move, size, i;
1177 	struct ext4_dir_entry_2 *de = NULL, *de2;
1178 	int	err = 0;
1179 
1180 	bh2 = ext4_append (handle, dir, &newblock, &err);
1181 	if (!(bh2)) {
1182 		brelse(*bh);
1183 		*bh = NULL;
1184 		goto errout;
1185 	}
1186 
1187 	BUFFER_TRACE(*bh, "get_write_access");
1188 	err = ext4_journal_get_write_access(handle, *bh);
1189 	if (err)
1190 		goto journal_error;
1191 
1192 	BUFFER_TRACE(frame->bh, "get_write_access");
1193 	err = ext4_journal_get_write_access(handle, frame->bh);
1194 	if (err)
1195 		goto journal_error;
1196 
1197 	data2 = bh2->b_data;
1198 
1199 	/* create map in the end of data2 block */
1200 	map = (struct dx_map_entry *) (data2 + blocksize);
1201 	count = dx_make_map ((struct ext4_dir_entry_2 *) data1,
1202 			     blocksize, hinfo, map);
1203 	map -= count;
1204 	dx_sort_map (map, count);
1205 	/* Split the existing block in the middle, size-wise */
1206 	size = 0;
1207 	move = 0;
1208 	for (i = count-1; i >= 0; i--) {
1209 		/* is more than half of this entry in 2nd half of the block? */
1210 		if (size + map[i].size/2 > blocksize/2)
1211 			break;
1212 		size += map[i].size;
1213 		move++;
1214 	}
1215 	/* map index at which we will split */
1216 	split = count - move;
1217 	hash2 = map[split].hash;
1218 	continued = hash2 == map[split - 1].hash;
1219 	dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1220 			(unsigned long)dx_get_block(frame->at),
1221 					hash2, split, count-split));
1222 
1223 	/* Fancy dance to stay within two buffers */
1224 	de2 = dx_move_dirents(data1, data2, map + split, count - split);
1225 	de = dx_pack_dirents(data1,blocksize);
1226 	de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de);
1227 	de2->rec_len = ext4_rec_len_to_disk(data2 + blocksize - (char *) de2);
1228 	dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1));
1229 	dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1));
1230 
1231 	/* Which block gets the new entry? */
1232 	if (hinfo->hash >= hash2)
1233 	{
1234 		swap(*bh, bh2);
1235 		de = de2;
1236 	}
1237 	dx_insert_block (frame, hash2 + continued, newblock);
1238 	err = ext4_journal_dirty_metadata (handle, bh2);
1239 	if (err)
1240 		goto journal_error;
1241 	err = ext4_journal_dirty_metadata (handle, frame->bh);
1242 	if (err)
1243 		goto journal_error;
1244 	brelse (bh2);
1245 	dxtrace(dx_show_index ("frame", frame->entries));
1246 	return de;
1247 
1248 journal_error:
1249 	brelse(*bh);
1250 	brelse(bh2);
1251 	*bh = NULL;
1252 	ext4_std_error(dir->i_sb, err);
1253 errout:
1254 	*error = err;
1255 	return NULL;
1256 }
1257 
1258 /*
1259  * Add a new entry into a directory (leaf) block.  If de is non-NULL,
1260  * it points to a directory entry which is guaranteed to be large
1261  * enough for new directory entry.  If de is NULL, then
1262  * add_dirent_to_buf will attempt search the directory block for
1263  * space.  It will return -ENOSPC if no space is available, and -EIO
1264  * and -EEXIST if directory entry already exists.
1265  *
1266  * NOTE!  bh is NOT released in the case where ENOSPC is returned.  In
1267  * all other cases bh is released.
1268  */
1269 static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
1270 			     struct inode *inode, struct ext4_dir_entry_2 *de,
1271 			     struct buffer_head * bh)
1272 {
1273 	struct inode	*dir = dentry->d_parent->d_inode;
1274 	const char	*name = dentry->d_name.name;
1275 	int		namelen = dentry->d_name.len;
1276 	unsigned long	offset = 0;
1277 	unsigned short	reclen;
1278 	int		nlen, rlen, err;
1279 	char		*top;
1280 
1281 	reclen = EXT4_DIR_REC_LEN(namelen);
1282 	if (!de) {
1283 		de = (struct ext4_dir_entry_2 *)bh->b_data;
1284 		top = bh->b_data + dir->i_sb->s_blocksize - reclen;
1285 		while ((char *) de <= top) {
1286 			if (!ext4_check_dir_entry("ext4_add_entry", dir, de,
1287 						  bh, offset)) {
1288 				brelse (bh);
1289 				return -EIO;
1290 			}
1291 			if (ext4_match (namelen, name, de)) {
1292 				brelse (bh);
1293 				return -EEXIST;
1294 			}
1295 			nlen = EXT4_DIR_REC_LEN(de->name_len);
1296 			rlen = ext4_rec_len_from_disk(de->rec_len);
1297 			if ((de->inode? rlen - nlen: rlen) >= reclen)
1298 				break;
1299 			de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1300 			offset += rlen;
1301 		}
1302 		if ((char *) de > top)
1303 			return -ENOSPC;
1304 	}
1305 	BUFFER_TRACE(bh, "get_write_access");
1306 	err = ext4_journal_get_write_access(handle, bh);
1307 	if (err) {
1308 		ext4_std_error(dir->i_sb, err);
1309 		brelse(bh);
1310 		return err;
1311 	}
1312 
1313 	/* By now the buffer is marked for journaling */
1314 	nlen = EXT4_DIR_REC_LEN(de->name_len);
1315 	rlen = ext4_rec_len_from_disk(de->rec_len);
1316 	if (de->inode) {
1317 		struct ext4_dir_entry_2 *de1 = (struct ext4_dir_entry_2 *)((char *)de + nlen);
1318 		de1->rec_len = ext4_rec_len_to_disk(rlen - nlen);
1319 		de->rec_len = ext4_rec_len_to_disk(nlen);
1320 		de = de1;
1321 	}
1322 	de->file_type = EXT4_FT_UNKNOWN;
1323 	if (inode) {
1324 		de->inode = cpu_to_le32(inode->i_ino);
1325 		ext4_set_de_type(dir->i_sb, de, inode->i_mode);
1326 	} else
1327 		de->inode = 0;
1328 	de->name_len = namelen;
1329 	memcpy (de->name, name, namelen);
1330 	/*
1331 	 * XXX shouldn't update any times until successful
1332 	 * completion of syscall, but too many callers depend
1333 	 * on this.
1334 	 *
1335 	 * XXX similarly, too many callers depend on
1336 	 * ext4_new_inode() setting the times, but error
1337 	 * recovery deletes the inode, so the worst that can
1338 	 * happen is that the times are slightly out of date
1339 	 * and/or different from the directory change time.
1340 	 */
1341 	dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
1342 	ext4_update_dx_flag(dir);
1343 	dir->i_version++;
1344 	ext4_mark_inode_dirty(handle, dir);
1345 	BUFFER_TRACE(bh, "call ext4_journal_dirty_metadata");
1346 	err = ext4_journal_dirty_metadata(handle, bh);
1347 	if (err)
1348 		ext4_std_error(dir->i_sb, err);
1349 	brelse(bh);
1350 	return 0;
1351 }
1352 
1353 /*
1354  * This converts a one block unindexed directory to a 3 block indexed
1355  * directory, and adds the dentry to the indexed directory.
1356  */
1357 static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
1358 			    struct inode *inode, struct buffer_head *bh)
1359 {
1360 	struct inode	*dir = dentry->d_parent->d_inode;
1361 	const char	*name = dentry->d_name.name;
1362 	int		namelen = dentry->d_name.len;
1363 	struct buffer_head *bh2;
1364 	struct dx_root	*root;
1365 	struct dx_frame	frames[2], *frame;
1366 	struct dx_entry *entries;
1367 	struct ext4_dir_entry_2	*de, *de2;
1368 	char		*data1, *top;
1369 	unsigned	len;
1370 	int		retval;
1371 	unsigned	blocksize;
1372 	struct dx_hash_info hinfo;
1373 	ext4_lblk_t  block;
1374 	struct fake_dirent *fde;
1375 
1376 	blocksize =  dir->i_sb->s_blocksize;
1377 	dxtrace(printk("Creating index\n"));
1378 	retval = ext4_journal_get_write_access(handle, bh);
1379 	if (retval) {
1380 		ext4_std_error(dir->i_sb, retval);
1381 		brelse(bh);
1382 		return retval;
1383 	}
1384 	root = (struct dx_root *) bh->b_data;
1385 
1386 	bh2 = ext4_append (handle, dir, &block, &retval);
1387 	if (!(bh2)) {
1388 		brelse(bh);
1389 		return retval;
1390 	}
1391 	EXT4_I(dir)->i_flags |= EXT4_INDEX_FL;
1392 	data1 = bh2->b_data;
1393 
1394 	/* The 0th block becomes the root, move the dirents out */
1395 	fde = &root->dotdot;
1396 	de = (struct ext4_dir_entry_2 *)((char *)fde +
1397 		ext4_rec_len_from_disk(fde->rec_len));
1398 	len = ((char *) root) + blocksize - (char *) de;
1399 	memcpy (data1, de, len);
1400 	de = (struct ext4_dir_entry_2 *) data1;
1401 	top = data1 + len;
1402 	while ((char *)(de2 = ext4_next_entry(de)) < top)
1403 		de = de2;
1404 	de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de);
1405 	/* Initialize the root; the dot dirents already exist */
1406 	de = (struct ext4_dir_entry_2 *) (&root->dotdot);
1407 	de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2));
1408 	memset (&root->info, 0, sizeof(root->info));
1409 	root->info.info_length = sizeof(root->info);
1410 	root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1411 	entries = root->entries;
1412 	dx_set_block (entries, 1);
1413 	dx_set_count (entries, 1);
1414 	dx_set_limit (entries, dx_root_limit(dir, sizeof(root->info)));
1415 
1416 	/* Initialize as for dx_probe */
1417 	hinfo.hash_version = root->info.hash_version;
1418 	hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1419 	ext4fs_dirhash(name, namelen, &hinfo);
1420 	frame = frames;
1421 	frame->entries = entries;
1422 	frame->at = entries;
1423 	frame->bh = bh;
1424 	bh = bh2;
1425 	de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
1426 	dx_release (frames);
1427 	if (!(de))
1428 		return retval;
1429 
1430 	return add_dirent_to_buf(handle, dentry, inode, de, bh);
1431 }
1432 
1433 /*
1434  *	ext4_add_entry()
1435  *
1436  * adds a file entry to the specified directory, using the same
1437  * semantics as ext4_find_entry(). It returns NULL if it failed.
1438  *
1439  * NOTE!! The inode part of 'de' is left at 0 - which means you
1440  * may not sleep between calling this and putting something into
1441  * the entry, as someone else might have used it while you slept.
1442  */
1443 static int ext4_add_entry (handle_t *handle, struct dentry *dentry,
1444 	struct inode *inode)
1445 {
1446 	struct inode *dir = dentry->d_parent->d_inode;
1447 	unsigned long offset;
1448 	struct buffer_head * bh;
1449 	struct ext4_dir_entry_2 *de;
1450 	struct super_block * sb;
1451 	int	retval;
1452 	int	dx_fallback=0;
1453 	unsigned blocksize;
1454 	ext4_lblk_t block, blocks;
1455 
1456 	sb = dir->i_sb;
1457 	blocksize = sb->s_blocksize;
1458 	if (!dentry->d_name.len)
1459 		return -EINVAL;
1460 	if (is_dx(dir)) {
1461 		retval = ext4_dx_add_entry(handle, dentry, inode);
1462 		if (!retval || (retval != ERR_BAD_DX_DIR))
1463 			return retval;
1464 		EXT4_I(dir)->i_flags &= ~EXT4_INDEX_FL;
1465 		dx_fallback++;
1466 		ext4_mark_inode_dirty(handle, dir);
1467 	}
1468 	blocks = dir->i_size >> sb->s_blocksize_bits;
1469 	for (block = 0, offset = 0; block < blocks; block++) {
1470 		bh = ext4_bread(handle, dir, block, 0, &retval);
1471 		if(!bh)
1472 			return retval;
1473 		retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1474 		if (retval != -ENOSPC)
1475 			return retval;
1476 
1477 		if (blocks == 1 && !dx_fallback &&
1478 		    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX))
1479 			return make_indexed_dir(handle, dentry, inode, bh);
1480 		brelse(bh);
1481 	}
1482 	bh = ext4_append(handle, dir, &block, &retval);
1483 	if (!bh)
1484 		return retval;
1485 	de = (struct ext4_dir_entry_2 *) bh->b_data;
1486 	de->inode = 0;
1487 	de->rec_len = ext4_rec_len_to_disk(blocksize);
1488 	return add_dirent_to_buf(handle, dentry, inode, de, bh);
1489 }
1490 
1491 /*
1492  * Returns 0 for success, or a negative error value
1493  */
1494 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
1495 			     struct inode *inode)
1496 {
1497 	struct dx_frame frames[2], *frame;
1498 	struct dx_entry *entries, *at;
1499 	struct dx_hash_info hinfo;
1500 	struct buffer_head * bh;
1501 	struct inode *dir = dentry->d_parent->d_inode;
1502 	struct super_block * sb = dir->i_sb;
1503 	struct ext4_dir_entry_2 *de;
1504 	int err;
1505 
1506 	frame = dx_probe(dentry, NULL, &hinfo, frames, &err);
1507 	if (!frame)
1508 		return err;
1509 	entries = frame->entries;
1510 	at = frame->at;
1511 
1512 	if (!(bh = ext4_bread(handle,dir, dx_get_block(frame->at), 0, &err)))
1513 		goto cleanup;
1514 
1515 	BUFFER_TRACE(bh, "get_write_access");
1516 	err = ext4_journal_get_write_access(handle, bh);
1517 	if (err)
1518 		goto journal_error;
1519 
1520 	err = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1521 	if (err != -ENOSPC) {
1522 		bh = NULL;
1523 		goto cleanup;
1524 	}
1525 
1526 	/* Block full, should compress but for now just split */
1527 	dxtrace(printk("using %u of %u node entries\n",
1528 		       dx_get_count(entries), dx_get_limit(entries)));
1529 	/* Need to split index? */
1530 	if (dx_get_count(entries) == dx_get_limit(entries)) {
1531 		ext4_lblk_t newblock;
1532 		unsigned icount = dx_get_count(entries);
1533 		int levels = frame - frames;
1534 		struct dx_entry *entries2;
1535 		struct dx_node *node2;
1536 		struct buffer_head *bh2;
1537 
1538 		if (levels && (dx_get_count(frames->entries) ==
1539 			       dx_get_limit(frames->entries))) {
1540 			ext4_warning(sb, __func__,
1541 				     "Directory index full!");
1542 			err = -ENOSPC;
1543 			goto cleanup;
1544 		}
1545 		bh2 = ext4_append (handle, dir, &newblock, &err);
1546 		if (!(bh2))
1547 			goto cleanup;
1548 		node2 = (struct dx_node *)(bh2->b_data);
1549 		entries2 = node2->entries;
1550 		node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize);
1551 		node2->fake.inode = 0;
1552 		BUFFER_TRACE(frame->bh, "get_write_access");
1553 		err = ext4_journal_get_write_access(handle, frame->bh);
1554 		if (err)
1555 			goto journal_error;
1556 		if (levels) {
1557 			unsigned icount1 = icount/2, icount2 = icount - icount1;
1558 			unsigned hash2 = dx_get_hash(entries + icount1);
1559 			dxtrace(printk("Split index %i/%i\n", icount1, icount2));
1560 
1561 			BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
1562 			err = ext4_journal_get_write_access(handle,
1563 							     frames[0].bh);
1564 			if (err)
1565 				goto journal_error;
1566 
1567 			memcpy ((char *) entries2, (char *) (entries + icount1),
1568 				icount2 * sizeof(struct dx_entry));
1569 			dx_set_count (entries, icount1);
1570 			dx_set_count (entries2, icount2);
1571 			dx_set_limit (entries2, dx_node_limit(dir));
1572 
1573 			/* Which index block gets the new entry? */
1574 			if (at - entries >= icount1) {
1575 				frame->at = at = at - entries - icount1 + entries2;
1576 				frame->entries = entries = entries2;
1577 				swap(frame->bh, bh2);
1578 			}
1579 			dx_insert_block (frames + 0, hash2, newblock);
1580 			dxtrace(dx_show_index ("node", frames[1].entries));
1581 			dxtrace(dx_show_index ("node",
1582 			       ((struct dx_node *) bh2->b_data)->entries));
1583 			err = ext4_journal_dirty_metadata(handle, bh2);
1584 			if (err)
1585 				goto journal_error;
1586 			brelse (bh2);
1587 		} else {
1588 			dxtrace(printk("Creating second level index...\n"));
1589 			memcpy((char *) entries2, (char *) entries,
1590 			       icount * sizeof(struct dx_entry));
1591 			dx_set_limit(entries2, dx_node_limit(dir));
1592 
1593 			/* Set up root */
1594 			dx_set_count(entries, 1);
1595 			dx_set_block(entries + 0, newblock);
1596 			((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
1597 
1598 			/* Add new access path frame */
1599 			frame = frames + 1;
1600 			frame->at = at = at - entries + entries2;
1601 			frame->entries = entries = entries2;
1602 			frame->bh = bh2;
1603 			err = ext4_journal_get_write_access(handle,
1604 							     frame->bh);
1605 			if (err)
1606 				goto journal_error;
1607 		}
1608 		ext4_journal_dirty_metadata(handle, frames[0].bh);
1609 	}
1610 	de = do_split(handle, dir, &bh, frame, &hinfo, &err);
1611 	if (!de)
1612 		goto cleanup;
1613 	err = add_dirent_to_buf(handle, dentry, inode, de, bh);
1614 	bh = NULL;
1615 	goto cleanup;
1616 
1617 journal_error:
1618 	ext4_std_error(dir->i_sb, err);
1619 cleanup:
1620 	if (bh)
1621 		brelse(bh);
1622 	dx_release(frames);
1623 	return err;
1624 }
1625 
1626 /*
1627  * ext4_delete_entry deletes a directory entry by merging it with the
1628  * previous entry
1629  */
1630 static int ext4_delete_entry (handle_t *handle,
1631 			      struct inode * dir,
1632 			      struct ext4_dir_entry_2 * de_del,
1633 			      struct buffer_head * bh)
1634 {
1635 	struct ext4_dir_entry_2 * de, * pde;
1636 	int i;
1637 
1638 	i = 0;
1639 	pde = NULL;
1640 	de = (struct ext4_dir_entry_2 *) bh->b_data;
1641 	while (i < bh->b_size) {
1642 		if (!ext4_check_dir_entry("ext4_delete_entry", dir, de, bh, i))
1643 			return -EIO;
1644 		if (de == de_del)  {
1645 			BUFFER_TRACE(bh, "get_write_access");
1646 			ext4_journal_get_write_access(handle, bh);
1647 			if (pde)
1648 				pde->rec_len = ext4_rec_len_to_disk(
1649 					ext4_rec_len_from_disk(pde->rec_len) +
1650 					ext4_rec_len_from_disk(de->rec_len));
1651 			else
1652 				de->inode = 0;
1653 			dir->i_version++;
1654 			BUFFER_TRACE(bh, "call ext4_journal_dirty_metadata");
1655 			ext4_journal_dirty_metadata(handle, bh);
1656 			return 0;
1657 		}
1658 		i += ext4_rec_len_from_disk(de->rec_len);
1659 		pde = de;
1660 		de = ext4_next_entry(de);
1661 	}
1662 	return -ENOENT;
1663 }
1664 
1665 /*
1666  * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
1667  * since this indicates that nlinks count was previously 1.
1668  */
1669 static void ext4_inc_count(handle_t *handle, struct inode *inode)
1670 {
1671 	inc_nlink(inode);
1672 	if (is_dx(inode) && inode->i_nlink > 1) {
1673 		/* limit is 16-bit i_links_count */
1674 		if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
1675 			inode->i_nlink = 1;
1676 			EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb,
1677 					      EXT4_FEATURE_RO_COMPAT_DIR_NLINK);
1678 		}
1679 	}
1680 }
1681 
1682 /*
1683  * If a directory had nlink == 1, then we should let it be 1. This indicates
1684  * directory has >EXT4_LINK_MAX subdirs.
1685  */
1686 static void ext4_dec_count(handle_t *handle, struct inode *inode)
1687 {
1688 	drop_nlink(inode);
1689 	if (S_ISDIR(inode->i_mode) && inode->i_nlink == 0)
1690 		inc_nlink(inode);
1691 }
1692 
1693 
1694 static int ext4_add_nondir(handle_t *handle,
1695 		struct dentry *dentry, struct inode *inode)
1696 {
1697 	int err = ext4_add_entry(handle, dentry, inode);
1698 	if (!err) {
1699 		ext4_mark_inode_dirty(handle, inode);
1700 		d_instantiate(dentry, inode);
1701 		return 0;
1702 	}
1703 	drop_nlink(inode);
1704 	iput(inode);
1705 	return err;
1706 }
1707 
1708 /*
1709  * By the time this is called, we already have created
1710  * the directory cache entry for the new file, but it
1711  * is so far negative - it has no inode.
1712  *
1713  * If the create succeeds, we fill in the inode information
1714  * with d_instantiate().
1715  */
1716 static int ext4_create (struct inode * dir, struct dentry * dentry, int mode,
1717 		struct nameidata *nd)
1718 {
1719 	handle_t *handle;
1720 	struct inode * inode;
1721 	int err, retries = 0;
1722 
1723 retry:
1724 	handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1725 					EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1726 					2*EXT4_QUOTA_INIT_BLOCKS(dir->i_sb));
1727 	if (IS_ERR(handle))
1728 		return PTR_ERR(handle);
1729 
1730 	if (IS_DIRSYNC(dir))
1731 		handle->h_sync = 1;
1732 
1733 	inode = ext4_new_inode (handle, dir, mode);
1734 	err = PTR_ERR(inode);
1735 	if (!IS_ERR(inode)) {
1736 		inode->i_op = &ext4_file_inode_operations;
1737 		inode->i_fop = &ext4_file_operations;
1738 		ext4_set_aops(inode);
1739 		err = ext4_add_nondir(handle, dentry, inode);
1740 	}
1741 	ext4_journal_stop(handle);
1742 	if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1743 		goto retry;
1744 	return err;
1745 }
1746 
1747 static int ext4_mknod (struct inode * dir, struct dentry *dentry,
1748 			int mode, dev_t rdev)
1749 {
1750 	handle_t *handle;
1751 	struct inode *inode;
1752 	int err, retries = 0;
1753 
1754 	if (!new_valid_dev(rdev))
1755 		return -EINVAL;
1756 
1757 retry:
1758 	handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1759 					EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1760 					2*EXT4_QUOTA_INIT_BLOCKS(dir->i_sb));
1761 	if (IS_ERR(handle))
1762 		return PTR_ERR(handle);
1763 
1764 	if (IS_DIRSYNC(dir))
1765 		handle->h_sync = 1;
1766 
1767 	inode = ext4_new_inode (handle, dir, mode);
1768 	err = PTR_ERR(inode);
1769 	if (!IS_ERR(inode)) {
1770 		init_special_inode(inode, inode->i_mode, rdev);
1771 #ifdef CONFIG_EXT4DEV_FS_XATTR
1772 		inode->i_op = &ext4_special_inode_operations;
1773 #endif
1774 		err = ext4_add_nondir(handle, dentry, inode);
1775 	}
1776 	ext4_journal_stop(handle);
1777 	if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1778 		goto retry;
1779 	return err;
1780 }
1781 
1782 static int ext4_mkdir(struct inode * dir, struct dentry * dentry, int mode)
1783 {
1784 	handle_t *handle;
1785 	struct inode * inode;
1786 	struct buffer_head * dir_block;
1787 	struct ext4_dir_entry_2 * de;
1788 	int err, retries = 0;
1789 
1790 	if (EXT4_DIR_LINK_MAX(dir))
1791 		return -EMLINK;
1792 
1793 retry:
1794 	handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1795 					EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1796 					2*EXT4_QUOTA_INIT_BLOCKS(dir->i_sb));
1797 	if (IS_ERR(handle))
1798 		return PTR_ERR(handle);
1799 
1800 	if (IS_DIRSYNC(dir))
1801 		handle->h_sync = 1;
1802 
1803 	inode = ext4_new_inode (handle, dir, S_IFDIR | mode);
1804 	err = PTR_ERR(inode);
1805 	if (IS_ERR(inode))
1806 		goto out_stop;
1807 
1808 	inode->i_op = &ext4_dir_inode_operations;
1809 	inode->i_fop = &ext4_dir_operations;
1810 	inode->i_size = EXT4_I(inode)->i_disksize = inode->i_sb->s_blocksize;
1811 	dir_block = ext4_bread (handle, inode, 0, 1, &err);
1812 	if (!dir_block)
1813 		goto out_clear_inode;
1814 	BUFFER_TRACE(dir_block, "get_write_access");
1815 	ext4_journal_get_write_access(handle, dir_block);
1816 	de = (struct ext4_dir_entry_2 *) dir_block->b_data;
1817 	de->inode = cpu_to_le32(inode->i_ino);
1818 	de->name_len = 1;
1819 	de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len));
1820 	strcpy (de->name, ".");
1821 	ext4_set_de_type(dir->i_sb, de, S_IFDIR);
1822 	de = ext4_next_entry(de);
1823 	de->inode = cpu_to_le32(dir->i_ino);
1824 	de->rec_len = ext4_rec_len_to_disk(inode->i_sb->s_blocksize -
1825 						EXT4_DIR_REC_LEN(1));
1826 	de->name_len = 2;
1827 	strcpy (de->name, "..");
1828 	ext4_set_de_type(dir->i_sb, de, S_IFDIR);
1829 	inode->i_nlink = 2;
1830 	BUFFER_TRACE(dir_block, "call ext4_journal_dirty_metadata");
1831 	ext4_journal_dirty_metadata(handle, dir_block);
1832 	brelse (dir_block);
1833 	ext4_mark_inode_dirty(handle, inode);
1834 	err = ext4_add_entry (handle, dentry, inode);
1835 	if (err) {
1836 out_clear_inode:
1837 		clear_nlink(inode);
1838 		ext4_mark_inode_dirty(handle, inode);
1839 		iput (inode);
1840 		goto out_stop;
1841 	}
1842 	ext4_inc_count(handle, dir);
1843 	ext4_update_dx_flag(dir);
1844 	ext4_mark_inode_dirty(handle, dir);
1845 	d_instantiate(dentry, inode);
1846 out_stop:
1847 	ext4_journal_stop(handle);
1848 	if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1849 		goto retry;
1850 	return err;
1851 }
1852 
1853 /*
1854  * routine to check that the specified directory is empty (for rmdir)
1855  */
1856 static int empty_dir (struct inode * inode)
1857 {
1858 	unsigned long offset;
1859 	struct buffer_head * bh;
1860 	struct ext4_dir_entry_2 * de, * de1;
1861 	struct super_block * sb;
1862 	int err = 0;
1863 
1864 	sb = inode->i_sb;
1865 	if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2) ||
1866 	    !(bh = ext4_bread (NULL, inode, 0, 0, &err))) {
1867 		if (err)
1868 			ext4_error(inode->i_sb, __func__,
1869 				   "error %d reading directory #%lu offset 0",
1870 				   err, inode->i_ino);
1871 		else
1872 			ext4_warning(inode->i_sb, __func__,
1873 				     "bad directory (dir #%lu) - no data block",
1874 				     inode->i_ino);
1875 		return 1;
1876 	}
1877 	de = (struct ext4_dir_entry_2 *) bh->b_data;
1878 	de1 = ext4_next_entry(de);
1879 	if (le32_to_cpu(de->inode) != inode->i_ino ||
1880 			!le32_to_cpu(de1->inode) ||
1881 			strcmp (".", de->name) ||
1882 			strcmp ("..", de1->name)) {
1883 		ext4_warning (inode->i_sb, "empty_dir",
1884 			      "bad directory (dir #%lu) - no `.' or `..'",
1885 			      inode->i_ino);
1886 		brelse (bh);
1887 		return 1;
1888 	}
1889 	offset = ext4_rec_len_from_disk(de->rec_len) +
1890 		 ext4_rec_len_from_disk(de1->rec_len);
1891 	de = ext4_next_entry(de1);
1892 	while (offset < inode->i_size ) {
1893 		if (!bh ||
1894 			(void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
1895 			err = 0;
1896 			brelse (bh);
1897 			bh = ext4_bread (NULL, inode,
1898 				offset >> EXT4_BLOCK_SIZE_BITS(sb), 0, &err);
1899 			if (!bh) {
1900 				if (err)
1901 					ext4_error(sb, __func__,
1902 						   "error %d reading directory"
1903 						   " #%lu offset %lu",
1904 						   err, inode->i_ino, offset);
1905 				offset += sb->s_blocksize;
1906 				continue;
1907 			}
1908 			de = (struct ext4_dir_entry_2 *) bh->b_data;
1909 		}
1910 		if (!ext4_check_dir_entry("empty_dir", inode, de, bh, offset)) {
1911 			de = (struct ext4_dir_entry_2 *)(bh->b_data +
1912 							 sb->s_blocksize);
1913 			offset = (offset | (sb->s_blocksize - 1)) + 1;
1914 			continue;
1915 		}
1916 		if (le32_to_cpu(de->inode)) {
1917 			brelse (bh);
1918 			return 0;
1919 		}
1920 		offset += ext4_rec_len_from_disk(de->rec_len);
1921 		de = ext4_next_entry(de);
1922 	}
1923 	brelse (bh);
1924 	return 1;
1925 }
1926 
1927 /* ext4_orphan_add() links an unlinked or truncated inode into a list of
1928  * such inodes, starting at the superblock, in case we crash before the
1929  * file is closed/deleted, or in case the inode truncate spans multiple
1930  * transactions and the last transaction is not recovered after a crash.
1931  *
1932  * At filesystem recovery time, we walk this list deleting unlinked
1933  * inodes and truncating linked inodes in ext4_orphan_cleanup().
1934  */
1935 int ext4_orphan_add(handle_t *handle, struct inode *inode)
1936 {
1937 	struct super_block *sb = inode->i_sb;
1938 	struct ext4_iloc iloc;
1939 	int err = 0, rc;
1940 
1941 	lock_super(sb);
1942 	if (!list_empty(&EXT4_I(inode)->i_orphan))
1943 		goto out_unlock;
1944 
1945 	/* Orphan handling is only valid for files with data blocks
1946 	 * being truncated, or files being unlinked. */
1947 
1948 	/* @@@ FIXME: Observation from aviro:
1949 	 * I think I can trigger J_ASSERT in ext4_orphan_add().  We block
1950 	 * here (on lock_super()), so race with ext4_link() which might bump
1951 	 * ->i_nlink. For, say it, character device. Not a regular file,
1952 	 * not a directory, not a symlink and ->i_nlink > 0.
1953 	 */
1954 	J_ASSERT ((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
1955 		S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
1956 
1957 	BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
1958 	err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
1959 	if (err)
1960 		goto out_unlock;
1961 
1962 	err = ext4_reserve_inode_write(handle, inode, &iloc);
1963 	if (err)
1964 		goto out_unlock;
1965 
1966 	/* Insert this inode at the head of the on-disk orphan list... */
1967 	NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan);
1968 	EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
1969 	err = ext4_journal_dirty_metadata(handle, EXT4_SB(sb)->s_sbh);
1970 	rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
1971 	if (!err)
1972 		err = rc;
1973 
1974 	/* Only add to the head of the in-memory list if all the
1975 	 * previous operations succeeded.  If the orphan_add is going to
1976 	 * fail (possibly taking the journal offline), we can't risk
1977 	 * leaving the inode on the orphan list: stray orphan-list
1978 	 * entries can cause panics at unmount time.
1979 	 *
1980 	 * This is safe: on error we're going to ignore the orphan list
1981 	 * anyway on the next recovery. */
1982 	if (!err)
1983 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
1984 
1985 	jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
1986 	jbd_debug(4, "orphan inode %lu will point to %d\n",
1987 			inode->i_ino, NEXT_ORPHAN(inode));
1988 out_unlock:
1989 	unlock_super(sb);
1990 	ext4_std_error(inode->i_sb, err);
1991 	return err;
1992 }
1993 
1994 /*
1995  * ext4_orphan_del() removes an unlinked or truncated inode from the list
1996  * of such inodes stored on disk, because it is finally being cleaned up.
1997  */
1998 int ext4_orphan_del(handle_t *handle, struct inode *inode)
1999 {
2000 	struct list_head *prev;
2001 	struct ext4_inode_info *ei = EXT4_I(inode);
2002 	struct ext4_sb_info *sbi;
2003 	unsigned long ino_next;
2004 	struct ext4_iloc iloc;
2005 	int err = 0;
2006 
2007 	lock_super(inode->i_sb);
2008 	if (list_empty(&ei->i_orphan)) {
2009 		unlock_super(inode->i_sb);
2010 		return 0;
2011 	}
2012 
2013 	ino_next = NEXT_ORPHAN(inode);
2014 	prev = ei->i_orphan.prev;
2015 	sbi = EXT4_SB(inode->i_sb);
2016 
2017 	jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2018 
2019 	list_del_init(&ei->i_orphan);
2020 
2021 	/* If we're on an error path, we may not have a valid
2022 	 * transaction handle with which to update the orphan list on
2023 	 * disk, but we still need to remove the inode from the linked
2024 	 * list in memory. */
2025 	if (!handle)
2026 		goto out;
2027 
2028 	err = ext4_reserve_inode_write(handle, inode, &iloc);
2029 	if (err)
2030 		goto out_err;
2031 
2032 	if (prev == &sbi->s_orphan) {
2033 		jbd_debug(4, "superblock will point to %lu\n", ino_next);
2034 		BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2035 		err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2036 		if (err)
2037 			goto out_brelse;
2038 		sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2039 		err = ext4_journal_dirty_metadata(handle, sbi->s_sbh);
2040 	} else {
2041 		struct ext4_iloc iloc2;
2042 		struct inode *i_prev =
2043 			&list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2044 
2045 		jbd_debug(4, "orphan inode %lu will point to %lu\n",
2046 			  i_prev->i_ino, ino_next);
2047 		err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2048 		if (err)
2049 			goto out_brelse;
2050 		NEXT_ORPHAN(i_prev) = ino_next;
2051 		err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2052 	}
2053 	if (err)
2054 		goto out_brelse;
2055 	NEXT_ORPHAN(inode) = 0;
2056 	err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2057 
2058 out_err:
2059 	ext4_std_error(inode->i_sb, err);
2060 out:
2061 	unlock_super(inode->i_sb);
2062 	return err;
2063 
2064 out_brelse:
2065 	brelse(iloc.bh);
2066 	goto out_err;
2067 }
2068 
2069 static int ext4_rmdir (struct inode * dir, struct dentry *dentry)
2070 {
2071 	int retval;
2072 	struct inode * inode;
2073 	struct buffer_head * bh;
2074 	struct ext4_dir_entry_2 * de;
2075 	handle_t *handle;
2076 
2077 	/* Initialize quotas before so that eventual writes go in
2078 	 * separate transaction */
2079 	DQUOT_INIT(dentry->d_inode);
2080 	handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2081 	if (IS_ERR(handle))
2082 		return PTR_ERR(handle);
2083 
2084 	retval = -ENOENT;
2085 	bh = ext4_find_entry (dentry, &de);
2086 	if (!bh)
2087 		goto end_rmdir;
2088 
2089 	if (IS_DIRSYNC(dir))
2090 		handle->h_sync = 1;
2091 
2092 	inode = dentry->d_inode;
2093 
2094 	retval = -EIO;
2095 	if (le32_to_cpu(de->inode) != inode->i_ino)
2096 		goto end_rmdir;
2097 
2098 	retval = -ENOTEMPTY;
2099 	if (!empty_dir (inode))
2100 		goto end_rmdir;
2101 
2102 	retval = ext4_delete_entry(handle, dir, de, bh);
2103 	if (retval)
2104 		goto end_rmdir;
2105 	if (!EXT4_DIR_LINK_EMPTY(inode))
2106 		ext4_warning (inode->i_sb, "ext4_rmdir",
2107 			      "empty directory has too many links (%d)",
2108 			      inode->i_nlink);
2109 	inode->i_version++;
2110 	clear_nlink(inode);
2111 	/* There's no need to set i_disksize: the fact that i_nlink is
2112 	 * zero will ensure that the right thing happens during any
2113 	 * recovery. */
2114 	inode->i_size = 0;
2115 	ext4_orphan_add(handle, inode);
2116 	inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
2117 	ext4_mark_inode_dirty(handle, inode);
2118 	ext4_dec_count(handle, dir);
2119 	ext4_update_dx_flag(dir);
2120 	ext4_mark_inode_dirty(handle, dir);
2121 
2122 end_rmdir:
2123 	ext4_journal_stop(handle);
2124 	brelse (bh);
2125 	return retval;
2126 }
2127 
2128 static int ext4_unlink(struct inode * dir, struct dentry *dentry)
2129 {
2130 	int retval;
2131 	struct inode * inode;
2132 	struct buffer_head * bh;
2133 	struct ext4_dir_entry_2 * de;
2134 	handle_t *handle;
2135 
2136 	/* Initialize quotas before so that eventual writes go
2137 	 * in separate transaction */
2138 	DQUOT_INIT(dentry->d_inode);
2139 	handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2140 	if (IS_ERR(handle))
2141 		return PTR_ERR(handle);
2142 
2143 	if (IS_DIRSYNC(dir))
2144 		handle->h_sync = 1;
2145 
2146 	retval = -ENOENT;
2147 	bh = ext4_find_entry (dentry, &de);
2148 	if (!bh)
2149 		goto end_unlink;
2150 
2151 	inode = dentry->d_inode;
2152 
2153 	retval = -EIO;
2154 	if (le32_to_cpu(de->inode) != inode->i_ino)
2155 		goto end_unlink;
2156 
2157 	if (!inode->i_nlink) {
2158 		ext4_warning (inode->i_sb, "ext4_unlink",
2159 			      "Deleting nonexistent file (%lu), %d",
2160 			      inode->i_ino, inode->i_nlink);
2161 		inode->i_nlink = 1;
2162 	}
2163 	retval = ext4_delete_entry(handle, dir, de, bh);
2164 	if (retval)
2165 		goto end_unlink;
2166 	dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
2167 	ext4_update_dx_flag(dir);
2168 	ext4_mark_inode_dirty(handle, dir);
2169 	drop_nlink(inode);
2170 	if (!inode->i_nlink)
2171 		ext4_orphan_add(handle, inode);
2172 	inode->i_ctime = ext4_current_time(inode);
2173 	ext4_mark_inode_dirty(handle, inode);
2174 	retval = 0;
2175 
2176 end_unlink:
2177 	ext4_journal_stop(handle);
2178 	brelse (bh);
2179 	return retval;
2180 }
2181 
2182 static int ext4_symlink (struct inode * dir,
2183 		struct dentry *dentry, const char * symname)
2184 {
2185 	handle_t *handle;
2186 	struct inode * inode;
2187 	int l, err, retries = 0;
2188 
2189 	l = strlen(symname)+1;
2190 	if (l > dir->i_sb->s_blocksize)
2191 		return -ENAMETOOLONG;
2192 
2193 retry:
2194 	handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2195 					EXT4_INDEX_EXTRA_TRANS_BLOCKS + 5 +
2196 					2*EXT4_QUOTA_INIT_BLOCKS(dir->i_sb));
2197 	if (IS_ERR(handle))
2198 		return PTR_ERR(handle);
2199 
2200 	if (IS_DIRSYNC(dir))
2201 		handle->h_sync = 1;
2202 
2203 	inode = ext4_new_inode (handle, dir, S_IFLNK|S_IRWXUGO);
2204 	err = PTR_ERR(inode);
2205 	if (IS_ERR(inode))
2206 		goto out_stop;
2207 
2208 	if (l > sizeof (EXT4_I(inode)->i_data)) {
2209 		inode->i_op = &ext4_symlink_inode_operations;
2210 		ext4_set_aops(inode);
2211 		/*
2212 		 * page_symlink() calls into ext4_prepare/commit_write.
2213 		 * We have a transaction open.  All is sweetness.  It also sets
2214 		 * i_size in generic_commit_write().
2215 		 */
2216 		err = __page_symlink(inode, symname, l,
2217 				mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS);
2218 		if (err) {
2219 			clear_nlink(inode);
2220 			ext4_mark_inode_dirty(handle, inode);
2221 			iput (inode);
2222 			goto out_stop;
2223 		}
2224 	} else {
2225 		/* clear the extent format for fast symlink */
2226 		EXT4_I(inode)->i_flags &= ~EXT4_EXTENTS_FL;
2227 		inode->i_op = &ext4_fast_symlink_inode_operations;
2228 		memcpy((char*)&EXT4_I(inode)->i_data,symname,l);
2229 		inode->i_size = l-1;
2230 	}
2231 	EXT4_I(inode)->i_disksize = inode->i_size;
2232 	err = ext4_add_nondir(handle, dentry, inode);
2233 out_stop:
2234 	ext4_journal_stop(handle);
2235 	if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2236 		goto retry;
2237 	return err;
2238 }
2239 
2240 static int ext4_link (struct dentry * old_dentry,
2241 		struct inode * dir, struct dentry *dentry)
2242 {
2243 	handle_t *handle;
2244 	struct inode *inode = old_dentry->d_inode;
2245 	int err, retries = 0;
2246 
2247 	if (EXT4_DIR_LINK_MAX(inode))
2248 		return -EMLINK;
2249 
2250 	/*
2251 	 * Return -ENOENT if we've raced with unlink and i_nlink is 0.  Doing
2252 	 * otherwise has the potential to corrupt the orphan inode list.
2253 	 */
2254 	if (inode->i_nlink == 0)
2255 		return -ENOENT;
2256 
2257 retry:
2258 	handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2259 					EXT4_INDEX_EXTRA_TRANS_BLOCKS);
2260 	if (IS_ERR(handle))
2261 		return PTR_ERR(handle);
2262 
2263 	if (IS_DIRSYNC(dir))
2264 		handle->h_sync = 1;
2265 
2266 	inode->i_ctime = ext4_current_time(inode);
2267 	ext4_inc_count(handle, inode);
2268 	atomic_inc(&inode->i_count);
2269 
2270 	err = ext4_add_nondir(handle, dentry, inode);
2271 	ext4_journal_stop(handle);
2272 	if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2273 		goto retry;
2274 	return err;
2275 }
2276 
2277 #define PARENT_INO(buffer) \
2278 	(ext4_next_entry((struct ext4_dir_entry_2 *)(buffer))->inode)
2279 
2280 /*
2281  * Anybody can rename anything with this: the permission checks are left to the
2282  * higher-level routines.
2283  */
2284 static int ext4_rename (struct inode * old_dir, struct dentry *old_dentry,
2285 			   struct inode * new_dir,struct dentry *new_dentry)
2286 {
2287 	handle_t *handle;
2288 	struct inode * old_inode, * new_inode;
2289 	struct buffer_head * old_bh, * new_bh, * dir_bh;
2290 	struct ext4_dir_entry_2 * old_de, * new_de;
2291 	int retval;
2292 
2293 	old_bh = new_bh = dir_bh = NULL;
2294 
2295 	/* Initialize quotas before so that eventual writes go
2296 	 * in separate transaction */
2297 	if (new_dentry->d_inode)
2298 		DQUOT_INIT(new_dentry->d_inode);
2299 	handle = ext4_journal_start(old_dir, 2 *
2300 					EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) +
2301 					EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
2302 	if (IS_ERR(handle))
2303 		return PTR_ERR(handle);
2304 
2305 	if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
2306 		handle->h_sync = 1;
2307 
2308 	old_bh = ext4_find_entry (old_dentry, &old_de);
2309 	/*
2310 	 *  Check for inode number is _not_ due to possible IO errors.
2311 	 *  We might rmdir the source, keep it as pwd of some process
2312 	 *  and merrily kill the link to whatever was created under the
2313 	 *  same name. Goodbye sticky bit ;-<
2314 	 */
2315 	old_inode = old_dentry->d_inode;
2316 	retval = -ENOENT;
2317 	if (!old_bh || le32_to_cpu(old_de->inode) != old_inode->i_ino)
2318 		goto end_rename;
2319 
2320 	new_inode = new_dentry->d_inode;
2321 	new_bh = ext4_find_entry (new_dentry, &new_de);
2322 	if (new_bh) {
2323 		if (!new_inode) {
2324 			brelse (new_bh);
2325 			new_bh = NULL;
2326 		}
2327 	}
2328 	if (S_ISDIR(old_inode->i_mode)) {
2329 		if (new_inode) {
2330 			retval = -ENOTEMPTY;
2331 			if (!empty_dir (new_inode))
2332 				goto end_rename;
2333 		}
2334 		retval = -EIO;
2335 		dir_bh = ext4_bread (handle, old_inode, 0, 0, &retval);
2336 		if (!dir_bh)
2337 			goto end_rename;
2338 		if (le32_to_cpu(PARENT_INO(dir_bh->b_data)) != old_dir->i_ino)
2339 			goto end_rename;
2340 		retval = -EMLINK;
2341 		if (!new_inode && new_dir!=old_dir &&
2342 				new_dir->i_nlink >= EXT4_LINK_MAX)
2343 			goto end_rename;
2344 	}
2345 	if (!new_bh) {
2346 		retval = ext4_add_entry (handle, new_dentry, old_inode);
2347 		if (retval)
2348 			goto end_rename;
2349 	} else {
2350 		BUFFER_TRACE(new_bh, "get write access");
2351 		ext4_journal_get_write_access(handle, new_bh);
2352 		new_de->inode = cpu_to_le32(old_inode->i_ino);
2353 		if (EXT4_HAS_INCOMPAT_FEATURE(new_dir->i_sb,
2354 					      EXT4_FEATURE_INCOMPAT_FILETYPE))
2355 			new_de->file_type = old_de->file_type;
2356 		new_dir->i_version++;
2357 		new_dir->i_ctime = new_dir->i_mtime =
2358 					ext4_current_time(new_dir);
2359 		ext4_mark_inode_dirty(handle, new_dir);
2360 		BUFFER_TRACE(new_bh, "call ext4_journal_dirty_metadata");
2361 		ext4_journal_dirty_metadata(handle, new_bh);
2362 		brelse(new_bh);
2363 		new_bh = NULL;
2364 	}
2365 
2366 	/*
2367 	 * Like most other Unix systems, set the ctime for inodes on a
2368 	 * rename.
2369 	 */
2370 	old_inode->i_ctime = ext4_current_time(old_inode);
2371 	ext4_mark_inode_dirty(handle, old_inode);
2372 
2373 	/*
2374 	 * ok, that's it
2375 	 */
2376 	if (le32_to_cpu(old_de->inode) != old_inode->i_ino ||
2377 	    old_de->name_len != old_dentry->d_name.len ||
2378 	    strncmp(old_de->name, old_dentry->d_name.name, old_de->name_len) ||
2379 	    (retval = ext4_delete_entry(handle, old_dir,
2380 					old_de, old_bh)) == -ENOENT) {
2381 		/* old_de could have moved from under us during htree split, so
2382 		 * make sure that we are deleting the right entry.  We might
2383 		 * also be pointing to a stale entry in the unused part of
2384 		 * old_bh so just checking inum and the name isn't enough. */
2385 		struct buffer_head *old_bh2;
2386 		struct ext4_dir_entry_2 *old_de2;
2387 
2388 		old_bh2 = ext4_find_entry(old_dentry, &old_de2);
2389 		if (old_bh2) {
2390 			retval = ext4_delete_entry(handle, old_dir,
2391 						   old_de2, old_bh2);
2392 			brelse(old_bh2);
2393 		}
2394 	}
2395 	if (retval) {
2396 		ext4_warning(old_dir->i_sb, "ext4_rename",
2397 				"Deleting old file (%lu), %d, error=%d",
2398 				old_dir->i_ino, old_dir->i_nlink, retval);
2399 	}
2400 
2401 	if (new_inode) {
2402 		ext4_dec_count(handle, new_inode);
2403 		new_inode->i_ctime = ext4_current_time(new_inode);
2404 	}
2405 	old_dir->i_ctime = old_dir->i_mtime = ext4_current_time(old_dir);
2406 	ext4_update_dx_flag(old_dir);
2407 	if (dir_bh) {
2408 		BUFFER_TRACE(dir_bh, "get_write_access");
2409 		ext4_journal_get_write_access(handle, dir_bh);
2410 		PARENT_INO(dir_bh->b_data) = cpu_to_le32(new_dir->i_ino);
2411 		BUFFER_TRACE(dir_bh, "call ext4_journal_dirty_metadata");
2412 		ext4_journal_dirty_metadata(handle, dir_bh);
2413 		ext4_dec_count(handle, old_dir);
2414 		if (new_inode) {
2415 			/* checked empty_dir above, can't have another parent,
2416 			 * ext4_dec_count() won't work for many-linked dirs */
2417 			new_inode->i_nlink = 0;
2418 		} else {
2419 			ext4_inc_count(handle, new_dir);
2420 			ext4_update_dx_flag(new_dir);
2421 			ext4_mark_inode_dirty(handle, new_dir);
2422 		}
2423 	}
2424 	ext4_mark_inode_dirty(handle, old_dir);
2425 	if (new_inode) {
2426 		ext4_mark_inode_dirty(handle, new_inode);
2427 		if (!new_inode->i_nlink)
2428 			ext4_orphan_add(handle, new_inode);
2429 	}
2430 	retval = 0;
2431 
2432 end_rename:
2433 	brelse (dir_bh);
2434 	brelse (old_bh);
2435 	brelse (new_bh);
2436 	ext4_journal_stop(handle);
2437 	return retval;
2438 }
2439 
2440 /*
2441  * directories can handle most operations...
2442  */
2443 const struct inode_operations ext4_dir_inode_operations = {
2444 	.create		= ext4_create,
2445 	.lookup		= ext4_lookup,
2446 	.link		= ext4_link,
2447 	.unlink		= ext4_unlink,
2448 	.symlink	= ext4_symlink,
2449 	.mkdir		= ext4_mkdir,
2450 	.rmdir		= ext4_rmdir,
2451 	.mknod		= ext4_mknod,
2452 	.rename		= ext4_rename,
2453 	.setattr	= ext4_setattr,
2454 #ifdef CONFIG_EXT4DEV_FS_XATTR
2455 	.setxattr	= generic_setxattr,
2456 	.getxattr	= generic_getxattr,
2457 	.listxattr	= ext4_listxattr,
2458 	.removexattr	= generic_removexattr,
2459 #endif
2460 	.permission	= ext4_permission,
2461 };
2462 
2463 const struct inode_operations ext4_special_inode_operations = {
2464 	.setattr	= ext4_setattr,
2465 #ifdef CONFIG_EXT4DEV_FS_XATTR
2466 	.setxattr	= generic_setxattr,
2467 	.getxattr	= generic_getxattr,
2468 	.listxattr	= ext4_listxattr,
2469 	.removexattr	= generic_removexattr,
2470 #endif
2471 	.permission	= ext4_permission,
2472 };
2473