xref: /openbmc/linux/fs/ext4/namei.c (revision f0702555)
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/time.h>
30 #include <linux/fcntl.h>
31 #include <linux/stat.h>
32 #include <linux/string.h>
33 #include <linux/quotaops.h>
34 #include <linux/buffer_head.h>
35 #include <linux/bio.h>
36 #include "ext4.h"
37 #include "ext4_jbd2.h"
38 
39 #include "xattr.h"
40 #include "acl.h"
41 
42 #include <trace/events/ext4.h>
43 /*
44  * define how far ahead to read directories while searching them.
45  */
46 #define NAMEI_RA_CHUNKS  2
47 #define NAMEI_RA_BLOCKS  4
48 #define NAMEI_RA_SIZE	     (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
49 
50 static struct buffer_head *ext4_append(handle_t *handle,
51 					struct inode *inode,
52 					ext4_lblk_t *block)
53 {
54 	struct buffer_head *bh;
55 	int err;
56 
57 	if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb &&
58 		     ((inode->i_size >> 10) >=
59 		      EXT4_SB(inode->i_sb)->s_max_dir_size_kb)))
60 		return ERR_PTR(-ENOSPC);
61 
62 	*block = inode->i_size >> inode->i_sb->s_blocksize_bits;
63 
64 	bh = ext4_bread(handle, inode, *block, EXT4_GET_BLOCKS_CREATE);
65 	if (IS_ERR(bh))
66 		return bh;
67 	inode->i_size += inode->i_sb->s_blocksize;
68 	EXT4_I(inode)->i_disksize = inode->i_size;
69 	BUFFER_TRACE(bh, "get_write_access");
70 	err = ext4_journal_get_write_access(handle, bh);
71 	if (err) {
72 		brelse(bh);
73 		ext4_std_error(inode->i_sb, err);
74 		return ERR_PTR(err);
75 	}
76 	return bh;
77 }
78 
79 static int ext4_dx_csum_verify(struct inode *inode,
80 			       struct ext4_dir_entry *dirent);
81 
82 typedef enum {
83 	EITHER, INDEX, DIRENT
84 } dirblock_type_t;
85 
86 #define ext4_read_dirblock(inode, block, type) \
87 	__ext4_read_dirblock((inode), (block), (type), __func__, __LINE__)
88 
89 static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
90 						ext4_lblk_t block,
91 						dirblock_type_t type,
92 						const char *func,
93 						unsigned int line)
94 {
95 	struct buffer_head *bh;
96 	struct ext4_dir_entry *dirent;
97 	int is_dx_block = 0;
98 
99 	bh = ext4_bread(NULL, inode, block, 0);
100 	if (IS_ERR(bh)) {
101 		__ext4_warning(inode->i_sb, func, line,
102 			       "inode #%lu: lblock %lu: comm %s: "
103 			       "error %ld reading directory block",
104 			       inode->i_ino, (unsigned long)block,
105 			       current->comm, PTR_ERR(bh));
106 
107 		return bh;
108 	}
109 	if (!bh) {
110 		ext4_error_inode(inode, func, line, block,
111 				 "Directory hole found");
112 		return ERR_PTR(-EFSCORRUPTED);
113 	}
114 	dirent = (struct ext4_dir_entry *) bh->b_data;
115 	/* Determine whether or not we have an index block */
116 	if (is_dx(inode)) {
117 		if (block == 0)
118 			is_dx_block = 1;
119 		else if (ext4_rec_len_from_disk(dirent->rec_len,
120 						inode->i_sb->s_blocksize) ==
121 			 inode->i_sb->s_blocksize)
122 			is_dx_block = 1;
123 	}
124 	if (!is_dx_block && type == INDEX) {
125 		ext4_error_inode(inode, func, line, block,
126 		       "directory leaf block found instead of index block");
127 		return ERR_PTR(-EFSCORRUPTED);
128 	}
129 	if (!ext4_has_metadata_csum(inode->i_sb) ||
130 	    buffer_verified(bh))
131 		return bh;
132 
133 	/*
134 	 * An empty leaf block can get mistaken for a index block; for
135 	 * this reason, we can only check the index checksum when the
136 	 * caller is sure it should be an index block.
137 	 */
138 	if (is_dx_block && type == INDEX) {
139 		if (ext4_dx_csum_verify(inode, dirent))
140 			set_buffer_verified(bh);
141 		else {
142 			ext4_error_inode(inode, func, line, block,
143 					 "Directory index failed checksum");
144 			brelse(bh);
145 			return ERR_PTR(-EFSBADCRC);
146 		}
147 	}
148 	if (!is_dx_block) {
149 		if (ext4_dirent_csum_verify(inode, dirent))
150 			set_buffer_verified(bh);
151 		else {
152 			ext4_error_inode(inode, func, line, block,
153 					 "Directory block failed checksum");
154 			brelse(bh);
155 			return ERR_PTR(-EFSBADCRC);
156 		}
157 	}
158 	return bh;
159 }
160 
161 #ifndef assert
162 #define assert(test) J_ASSERT(test)
163 #endif
164 
165 #ifdef DX_DEBUG
166 #define dxtrace(command) command
167 #else
168 #define dxtrace(command)
169 #endif
170 
171 struct fake_dirent
172 {
173 	__le32 inode;
174 	__le16 rec_len;
175 	u8 name_len;
176 	u8 file_type;
177 };
178 
179 struct dx_countlimit
180 {
181 	__le16 limit;
182 	__le16 count;
183 };
184 
185 struct dx_entry
186 {
187 	__le32 hash;
188 	__le32 block;
189 };
190 
191 /*
192  * dx_root_info is laid out so that if it should somehow get overlaid by a
193  * dirent the two low bits of the hash version will be zero.  Therefore, the
194  * hash version mod 4 should never be 0.  Sincerely, the paranoia department.
195  */
196 
197 struct dx_root
198 {
199 	struct fake_dirent dot;
200 	char dot_name[4];
201 	struct fake_dirent dotdot;
202 	char dotdot_name[4];
203 	struct dx_root_info
204 	{
205 		__le32 reserved_zero;
206 		u8 hash_version;
207 		u8 info_length; /* 8 */
208 		u8 indirect_levels;
209 		u8 unused_flags;
210 	}
211 	info;
212 	struct dx_entry	entries[0];
213 };
214 
215 struct dx_node
216 {
217 	struct fake_dirent fake;
218 	struct dx_entry	entries[0];
219 };
220 
221 
222 struct dx_frame
223 {
224 	struct buffer_head *bh;
225 	struct dx_entry *entries;
226 	struct dx_entry *at;
227 };
228 
229 struct dx_map_entry
230 {
231 	u32 hash;
232 	u16 offs;
233 	u16 size;
234 };
235 
236 /*
237  * This goes at the end of each htree block.
238  */
239 struct dx_tail {
240 	u32 dt_reserved;
241 	__le32 dt_checksum;	/* crc32c(uuid+inum+dirblock) */
242 };
243 
244 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
245 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
246 static inline unsigned dx_get_hash(struct dx_entry *entry);
247 static void dx_set_hash(struct dx_entry *entry, unsigned value);
248 static unsigned dx_get_count(struct dx_entry *entries);
249 static unsigned dx_get_limit(struct dx_entry *entries);
250 static void dx_set_count(struct dx_entry *entries, unsigned value);
251 static void dx_set_limit(struct dx_entry *entries, unsigned value);
252 static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
253 static unsigned dx_node_limit(struct inode *dir);
254 static struct dx_frame *dx_probe(struct ext4_filename *fname,
255 				 struct inode *dir,
256 				 struct dx_hash_info *hinfo,
257 				 struct dx_frame *frame);
258 static void dx_release(struct dx_frame *frames);
259 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
260 		       unsigned blocksize, struct dx_hash_info *hinfo,
261 		       struct dx_map_entry map[]);
262 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
263 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
264 		struct dx_map_entry *offsets, int count, unsigned blocksize);
265 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
266 static void dx_insert_block(struct dx_frame *frame,
267 					u32 hash, ext4_lblk_t block);
268 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
269 				 struct dx_frame *frame,
270 				 struct dx_frame *frames,
271 				 __u32 *start_hash);
272 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
273 		struct ext4_filename *fname,
274 		struct ext4_dir_entry_2 **res_dir);
275 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
276 			     struct inode *dir, struct inode *inode);
277 
278 /* checksumming functions */
279 void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
280 			    unsigned int blocksize)
281 {
282 	memset(t, 0, sizeof(struct ext4_dir_entry_tail));
283 	t->det_rec_len = ext4_rec_len_to_disk(
284 			sizeof(struct ext4_dir_entry_tail), blocksize);
285 	t->det_reserved_ft = EXT4_FT_DIR_CSUM;
286 }
287 
288 /* Walk through a dirent block to find a checksum "dirent" at the tail */
289 static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
290 						   struct ext4_dir_entry *de)
291 {
292 	struct ext4_dir_entry_tail *t;
293 
294 #ifdef PARANOID
295 	struct ext4_dir_entry *d, *top;
296 
297 	d = de;
298 	top = (struct ext4_dir_entry *)(((void *)de) +
299 		(EXT4_BLOCK_SIZE(inode->i_sb) -
300 		sizeof(struct ext4_dir_entry_tail)));
301 	while (d < top && d->rec_len)
302 		d = (struct ext4_dir_entry *)(((void *)d) +
303 		    le16_to_cpu(d->rec_len));
304 
305 	if (d != top)
306 		return NULL;
307 
308 	t = (struct ext4_dir_entry_tail *)d;
309 #else
310 	t = EXT4_DIRENT_TAIL(de, EXT4_BLOCK_SIZE(inode->i_sb));
311 #endif
312 
313 	if (t->det_reserved_zero1 ||
314 	    le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
315 	    t->det_reserved_zero2 ||
316 	    t->det_reserved_ft != EXT4_FT_DIR_CSUM)
317 		return NULL;
318 
319 	return t;
320 }
321 
322 static __le32 ext4_dirent_csum(struct inode *inode,
323 			       struct ext4_dir_entry *dirent, int size)
324 {
325 	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
326 	struct ext4_inode_info *ei = EXT4_I(inode);
327 	__u32 csum;
328 
329 	csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
330 	return cpu_to_le32(csum);
331 }
332 
333 #define warn_no_space_for_csum(inode)					\
334 	__warn_no_space_for_csum((inode), __func__, __LINE__)
335 
336 static void __warn_no_space_for_csum(struct inode *inode, const char *func,
337 				     unsigned int line)
338 {
339 	__ext4_warning_inode(inode, func, line,
340 		"No space for directory leaf checksum. Please run e2fsck -D.");
341 }
342 
343 int ext4_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent)
344 {
345 	struct ext4_dir_entry_tail *t;
346 
347 	if (!ext4_has_metadata_csum(inode->i_sb))
348 		return 1;
349 
350 	t = get_dirent_tail(inode, dirent);
351 	if (!t) {
352 		warn_no_space_for_csum(inode);
353 		return 0;
354 	}
355 
356 	if (t->det_checksum != ext4_dirent_csum(inode, dirent,
357 						(void *)t - (void *)dirent))
358 		return 0;
359 
360 	return 1;
361 }
362 
363 static void ext4_dirent_csum_set(struct inode *inode,
364 				 struct ext4_dir_entry *dirent)
365 {
366 	struct ext4_dir_entry_tail *t;
367 
368 	if (!ext4_has_metadata_csum(inode->i_sb))
369 		return;
370 
371 	t = get_dirent_tail(inode, dirent);
372 	if (!t) {
373 		warn_no_space_for_csum(inode);
374 		return;
375 	}
376 
377 	t->det_checksum = ext4_dirent_csum(inode, dirent,
378 					   (void *)t - (void *)dirent);
379 }
380 
381 int ext4_handle_dirty_dirent_node(handle_t *handle,
382 				  struct inode *inode,
383 				  struct buffer_head *bh)
384 {
385 	ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
386 	return ext4_handle_dirty_metadata(handle, inode, bh);
387 }
388 
389 static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
390 					       struct ext4_dir_entry *dirent,
391 					       int *offset)
392 {
393 	struct ext4_dir_entry *dp;
394 	struct dx_root_info *root;
395 	int count_offset;
396 
397 	if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
398 		count_offset = 8;
399 	else if (le16_to_cpu(dirent->rec_len) == 12) {
400 		dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
401 		if (le16_to_cpu(dp->rec_len) !=
402 		    EXT4_BLOCK_SIZE(inode->i_sb) - 12)
403 			return NULL;
404 		root = (struct dx_root_info *)(((void *)dp + 12));
405 		if (root->reserved_zero ||
406 		    root->info_length != sizeof(struct dx_root_info))
407 			return NULL;
408 		count_offset = 32;
409 	} else
410 		return NULL;
411 
412 	if (offset)
413 		*offset = count_offset;
414 	return (struct dx_countlimit *)(((void *)dirent) + count_offset);
415 }
416 
417 static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
418 			   int count_offset, int count, struct dx_tail *t)
419 {
420 	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
421 	struct ext4_inode_info *ei = EXT4_I(inode);
422 	__u32 csum;
423 	__le32 save_csum;
424 	int size;
425 
426 	size = count_offset + (count * sizeof(struct dx_entry));
427 	save_csum = t->dt_checksum;
428 	t->dt_checksum = 0;
429 	csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
430 	csum = ext4_chksum(sbi, csum, (__u8 *)t, sizeof(struct dx_tail));
431 	t->dt_checksum = save_csum;
432 
433 	return cpu_to_le32(csum);
434 }
435 
436 static int ext4_dx_csum_verify(struct inode *inode,
437 			       struct ext4_dir_entry *dirent)
438 {
439 	struct dx_countlimit *c;
440 	struct dx_tail *t;
441 	int count_offset, limit, count;
442 
443 	if (!ext4_has_metadata_csum(inode->i_sb))
444 		return 1;
445 
446 	c = get_dx_countlimit(inode, dirent, &count_offset);
447 	if (!c) {
448 		EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
449 		return 1;
450 	}
451 	limit = le16_to_cpu(c->limit);
452 	count = le16_to_cpu(c->count);
453 	if (count_offset + (limit * sizeof(struct dx_entry)) >
454 	    EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
455 		warn_no_space_for_csum(inode);
456 		return 1;
457 	}
458 	t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
459 
460 	if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
461 					    count, t))
462 		return 0;
463 	return 1;
464 }
465 
466 static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
467 {
468 	struct dx_countlimit *c;
469 	struct dx_tail *t;
470 	int count_offset, limit, count;
471 
472 	if (!ext4_has_metadata_csum(inode->i_sb))
473 		return;
474 
475 	c = get_dx_countlimit(inode, dirent, &count_offset);
476 	if (!c) {
477 		EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
478 		return;
479 	}
480 	limit = le16_to_cpu(c->limit);
481 	count = le16_to_cpu(c->count);
482 	if (count_offset + (limit * sizeof(struct dx_entry)) >
483 	    EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
484 		warn_no_space_for_csum(inode);
485 		return;
486 	}
487 	t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
488 
489 	t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
490 }
491 
492 static inline int ext4_handle_dirty_dx_node(handle_t *handle,
493 					    struct inode *inode,
494 					    struct buffer_head *bh)
495 {
496 	ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
497 	return ext4_handle_dirty_metadata(handle, inode, bh);
498 }
499 
500 /*
501  * p is at least 6 bytes before the end of page
502  */
503 static inline struct ext4_dir_entry_2 *
504 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
505 {
506 	return (struct ext4_dir_entry_2 *)((char *)p +
507 		ext4_rec_len_from_disk(p->rec_len, blocksize));
508 }
509 
510 /*
511  * Future: use high four bits of block for coalesce-on-delete flags
512  * Mask them off for now.
513  */
514 
515 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
516 {
517 	return le32_to_cpu(entry->block) & 0x00ffffff;
518 }
519 
520 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
521 {
522 	entry->block = cpu_to_le32(value);
523 }
524 
525 static inline unsigned dx_get_hash(struct dx_entry *entry)
526 {
527 	return le32_to_cpu(entry->hash);
528 }
529 
530 static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
531 {
532 	entry->hash = cpu_to_le32(value);
533 }
534 
535 static inline unsigned dx_get_count(struct dx_entry *entries)
536 {
537 	return le16_to_cpu(((struct dx_countlimit *) entries)->count);
538 }
539 
540 static inline unsigned dx_get_limit(struct dx_entry *entries)
541 {
542 	return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
543 }
544 
545 static inline void dx_set_count(struct dx_entry *entries, unsigned value)
546 {
547 	((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
548 }
549 
550 static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
551 {
552 	((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
553 }
554 
555 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
556 {
557 	unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
558 		EXT4_DIR_REC_LEN(2) - infosize;
559 
560 	if (ext4_has_metadata_csum(dir->i_sb))
561 		entry_space -= sizeof(struct dx_tail);
562 	return entry_space / sizeof(struct dx_entry);
563 }
564 
565 static inline unsigned dx_node_limit(struct inode *dir)
566 {
567 	unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
568 
569 	if (ext4_has_metadata_csum(dir->i_sb))
570 		entry_space -= sizeof(struct dx_tail);
571 	return entry_space / sizeof(struct dx_entry);
572 }
573 
574 /*
575  * Debug
576  */
577 #ifdef DX_DEBUG
578 static void dx_show_index(char * label, struct dx_entry *entries)
579 {
580 	int i, n = dx_get_count (entries);
581 	printk(KERN_DEBUG "%s index ", label);
582 	for (i = 0; i < n; i++) {
583 		printk("%x->%lu ", i ? dx_get_hash(entries + i) :
584 				0, (unsigned long)dx_get_block(entries + i));
585 	}
586 	printk("\n");
587 }
588 
589 struct stats
590 {
591 	unsigned names;
592 	unsigned space;
593 	unsigned bcount;
594 };
595 
596 static struct stats dx_show_leaf(struct inode *dir,
597 				struct dx_hash_info *hinfo,
598 				struct ext4_dir_entry_2 *de,
599 				int size, int show_names)
600 {
601 	unsigned names = 0, space = 0;
602 	char *base = (char *) de;
603 	struct dx_hash_info h = *hinfo;
604 
605 	printk("names: ");
606 	while ((char *) de < base + size)
607 	{
608 		if (de->inode)
609 		{
610 			if (show_names)
611 			{
612 #ifdef CONFIG_EXT4_FS_ENCRYPTION
613 				int len;
614 				char *name;
615 				struct ext4_str fname_crypto_str
616 					= {.name = NULL, .len = 0};
617 				int res = 0;
618 
619 				name  = de->name;
620 				len = de->name_len;
621 				if (ext4_encrypted_inode(inode))
622 					res = ext4_get_encryption_info(dir);
623 				if (res) {
624 					printk(KERN_WARNING "Error setting up"
625 					       " fname crypto: %d\n", res);
626 				}
627 				if (ctx == NULL) {
628 					/* Directory is not encrypted */
629 					ext4fs_dirhash(de->name,
630 						de->name_len, &h);
631 					printk("%*.s:(U)%x.%u ", len,
632 					       name, h.hash,
633 					       (unsigned) ((char *) de
634 							   - base));
635 				} else {
636 					/* Directory is encrypted */
637 					res = ext4_fname_crypto_alloc_buffer(
638 						ctx, de->name_len,
639 						&fname_crypto_str);
640 					if (res < 0) {
641 						printk(KERN_WARNING "Error "
642 							"allocating crypto "
643 							"buffer--skipping "
644 							"crypto\n");
645 						ctx = NULL;
646 					}
647 					res = ext4_fname_disk_to_usr(ctx, NULL, de,
648 							&fname_crypto_str);
649 					if (res < 0) {
650 						printk(KERN_WARNING "Error "
651 							"converting filename "
652 							"from disk to usr"
653 							"\n");
654 						name = "??";
655 						len = 2;
656 					} else {
657 						name = fname_crypto_str.name;
658 						len = fname_crypto_str.len;
659 					}
660 					ext4fs_dirhash(de->name, de->name_len,
661 						       &h);
662 					printk("%*.s:(E)%x.%u ", len, name,
663 					       h.hash, (unsigned) ((char *) de
664 								   - base));
665 					ext4_fname_crypto_free_buffer(
666 						&fname_crypto_str);
667 				}
668 #else
669 				int len = de->name_len;
670 				char *name = de->name;
671 				ext4fs_dirhash(de->name, de->name_len, &h);
672 				printk("%*.s:%x.%u ", len, name, h.hash,
673 				       (unsigned) ((char *) de - base));
674 #endif
675 			}
676 			space += EXT4_DIR_REC_LEN(de->name_len);
677 			names++;
678 		}
679 		de = ext4_next_entry(de, size);
680 	}
681 	printk("(%i)\n", names);
682 	return (struct stats) { names, space, 1 };
683 }
684 
685 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
686 			     struct dx_entry *entries, int levels)
687 {
688 	unsigned blocksize = dir->i_sb->s_blocksize;
689 	unsigned count = dx_get_count(entries), names = 0, space = 0, i;
690 	unsigned bcount = 0;
691 	struct buffer_head *bh;
692 	printk("%i indexed blocks...\n", count);
693 	for (i = 0; i < count; i++, entries++)
694 	{
695 		ext4_lblk_t block = dx_get_block(entries);
696 		ext4_lblk_t hash  = i ? dx_get_hash(entries): 0;
697 		u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
698 		struct stats stats;
699 		printk("%s%3u:%03u hash %8x/%8x ",levels?"":"   ", i, block, hash, range);
700 		bh = ext4_bread(NULL,dir, block, 0);
701 		if (!bh || IS_ERR(bh))
702 			continue;
703 		stats = levels?
704 		   dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
705 		   dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *)
706 			bh->b_data, blocksize, 0);
707 		names += stats.names;
708 		space += stats.space;
709 		bcount += stats.bcount;
710 		brelse(bh);
711 	}
712 	if (bcount)
713 		printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
714 		       levels ? "" : "   ", names, space/bcount,
715 		       (space/bcount)*100/blocksize);
716 	return (struct stats) { names, space, bcount};
717 }
718 #endif /* DX_DEBUG */
719 
720 /*
721  * Probe for a directory leaf block to search.
722  *
723  * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
724  * error in the directory index, and the caller should fall back to
725  * searching the directory normally.  The callers of dx_probe **MUST**
726  * check for this error code, and make sure it never gets reflected
727  * back to userspace.
728  */
729 static struct dx_frame *
730 dx_probe(struct ext4_filename *fname, struct inode *dir,
731 	 struct dx_hash_info *hinfo, struct dx_frame *frame_in)
732 {
733 	unsigned count, indirect;
734 	struct dx_entry *at, *entries, *p, *q, *m;
735 	struct dx_root *root;
736 	struct dx_frame *frame = frame_in;
737 	struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
738 	u32 hash;
739 
740 	frame->bh = ext4_read_dirblock(dir, 0, INDEX);
741 	if (IS_ERR(frame->bh))
742 		return (struct dx_frame *) frame->bh;
743 
744 	root = (struct dx_root *) frame->bh->b_data;
745 	if (root->info.hash_version != DX_HASH_TEA &&
746 	    root->info.hash_version != DX_HASH_HALF_MD4 &&
747 	    root->info.hash_version != DX_HASH_LEGACY) {
748 		ext4_warning_inode(dir, "Unrecognised inode hash code %u",
749 				   root->info.hash_version);
750 		goto fail;
751 	}
752 	if (fname)
753 		hinfo = &fname->hinfo;
754 	hinfo->hash_version = root->info.hash_version;
755 	if (hinfo->hash_version <= DX_HASH_TEA)
756 		hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
757 	hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
758 	if (fname && fname_name(fname))
759 		ext4fs_dirhash(fname_name(fname), fname_len(fname), hinfo);
760 	hash = hinfo->hash;
761 
762 	if (root->info.unused_flags & 1) {
763 		ext4_warning_inode(dir, "Unimplemented hash flags: %#06x",
764 				   root->info.unused_flags);
765 		goto fail;
766 	}
767 
768 	indirect = root->info.indirect_levels;
769 	if (indirect > 1) {
770 		ext4_warning_inode(dir, "Unimplemented hash depth: %#06x",
771 				   root->info.indirect_levels);
772 		goto fail;
773 	}
774 
775 	entries = (struct dx_entry *)(((char *)&root->info) +
776 				      root->info.info_length);
777 
778 	if (dx_get_limit(entries) != dx_root_limit(dir,
779 						   root->info.info_length)) {
780 		ext4_warning_inode(dir, "dx entry: limit %u != root limit %u",
781 				   dx_get_limit(entries),
782 				   dx_root_limit(dir, root->info.info_length));
783 		goto fail;
784 	}
785 
786 	dxtrace(printk("Look up %x", hash));
787 	while (1) {
788 		count = dx_get_count(entries);
789 		if (!count || count > dx_get_limit(entries)) {
790 			ext4_warning_inode(dir,
791 					   "dx entry: count %u beyond limit %u",
792 					   count, dx_get_limit(entries));
793 			goto fail;
794 		}
795 
796 		p = entries + 1;
797 		q = entries + count - 1;
798 		while (p <= q) {
799 			m = p + (q - p) / 2;
800 			dxtrace(printk("."));
801 			if (dx_get_hash(m) > hash)
802 				q = m - 1;
803 			else
804 				p = m + 1;
805 		}
806 
807 		if (0) { // linear search cross check
808 			unsigned n = count - 1;
809 			at = entries;
810 			while (n--)
811 			{
812 				dxtrace(printk(","));
813 				if (dx_get_hash(++at) > hash)
814 				{
815 					at--;
816 					break;
817 				}
818 			}
819 			assert (at == p - 1);
820 		}
821 
822 		at = p - 1;
823 		dxtrace(printk(" %x->%u\n", at == entries ? 0 : dx_get_hash(at),
824 			       dx_get_block(at)));
825 		frame->entries = entries;
826 		frame->at = at;
827 		if (!indirect--)
828 			return frame;
829 		frame++;
830 		frame->bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX);
831 		if (IS_ERR(frame->bh)) {
832 			ret_err = (struct dx_frame *) frame->bh;
833 			frame->bh = NULL;
834 			goto fail;
835 		}
836 		entries = ((struct dx_node *) frame->bh->b_data)->entries;
837 
838 		if (dx_get_limit(entries) != dx_node_limit(dir)) {
839 			ext4_warning_inode(dir,
840 				"dx entry: limit %u != node limit %u",
841 				dx_get_limit(entries), dx_node_limit(dir));
842 			goto fail;
843 		}
844 	}
845 fail:
846 	while (frame >= frame_in) {
847 		brelse(frame->bh);
848 		frame--;
849 	}
850 
851 	if (ret_err == ERR_PTR(ERR_BAD_DX_DIR))
852 		ext4_warning_inode(dir,
853 			"Corrupt directory, running e2fsck is recommended");
854 	return ret_err;
855 }
856 
857 static void dx_release(struct dx_frame *frames)
858 {
859 	if (frames[0].bh == NULL)
860 		return;
861 
862 	if (((struct dx_root *)frames[0].bh->b_data)->info.indirect_levels)
863 		brelse(frames[1].bh);
864 	brelse(frames[0].bh);
865 }
866 
867 /*
868  * This function increments the frame pointer to search the next leaf
869  * block, and reads in the necessary intervening nodes if the search
870  * should be necessary.  Whether or not the search is necessary is
871  * controlled by the hash parameter.  If the hash value is even, then
872  * the search is only continued if the next block starts with that
873  * hash value.  This is used if we are searching for a specific file.
874  *
875  * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
876  *
877  * This function returns 1 if the caller should continue to search,
878  * or 0 if it should not.  If there is an error reading one of the
879  * index blocks, it will a negative error code.
880  *
881  * If start_hash is non-null, it will be filled in with the starting
882  * hash of the next page.
883  */
884 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
885 				 struct dx_frame *frame,
886 				 struct dx_frame *frames,
887 				 __u32 *start_hash)
888 {
889 	struct dx_frame *p;
890 	struct buffer_head *bh;
891 	int num_frames = 0;
892 	__u32 bhash;
893 
894 	p = frame;
895 	/*
896 	 * Find the next leaf page by incrementing the frame pointer.
897 	 * If we run out of entries in the interior node, loop around and
898 	 * increment pointer in the parent node.  When we break out of
899 	 * this loop, num_frames indicates the number of interior
900 	 * nodes need to be read.
901 	 */
902 	while (1) {
903 		if (++(p->at) < p->entries + dx_get_count(p->entries))
904 			break;
905 		if (p == frames)
906 			return 0;
907 		num_frames++;
908 		p--;
909 	}
910 
911 	/*
912 	 * If the hash is 1, then continue only if the next page has a
913 	 * continuation hash of any value.  This is used for readdir
914 	 * handling.  Otherwise, check to see if the hash matches the
915 	 * desired contiuation hash.  If it doesn't, return since
916 	 * there's no point to read in the successive index pages.
917 	 */
918 	bhash = dx_get_hash(p->at);
919 	if (start_hash)
920 		*start_hash = bhash;
921 	if ((hash & 1) == 0) {
922 		if ((bhash & ~1) != hash)
923 			return 0;
924 	}
925 	/*
926 	 * If the hash is HASH_NB_ALWAYS, we always go to the next
927 	 * block so no check is necessary
928 	 */
929 	while (num_frames--) {
930 		bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX);
931 		if (IS_ERR(bh))
932 			return PTR_ERR(bh);
933 		p++;
934 		brelse(p->bh);
935 		p->bh = bh;
936 		p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
937 	}
938 	return 1;
939 }
940 
941 
942 /*
943  * This function fills a red-black tree with information from a
944  * directory block.  It returns the number directory entries loaded
945  * into the tree.  If there is an error it is returned in err.
946  */
947 static int htree_dirblock_to_tree(struct file *dir_file,
948 				  struct inode *dir, ext4_lblk_t block,
949 				  struct dx_hash_info *hinfo,
950 				  __u32 start_hash, __u32 start_minor_hash)
951 {
952 	struct buffer_head *bh;
953 	struct ext4_dir_entry_2 *de, *top;
954 	int err = 0, count = 0;
955 	struct ext4_str fname_crypto_str = {.name = NULL, .len = 0}, tmp_str;
956 
957 	dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
958 							(unsigned long)block));
959 	bh = ext4_read_dirblock(dir, block, DIRENT);
960 	if (IS_ERR(bh))
961 		return PTR_ERR(bh);
962 
963 	de = (struct ext4_dir_entry_2 *) bh->b_data;
964 	top = (struct ext4_dir_entry_2 *) ((char *) de +
965 					   dir->i_sb->s_blocksize -
966 					   EXT4_DIR_REC_LEN(0));
967 #ifdef CONFIG_EXT4_FS_ENCRYPTION
968 	/* Check if the directory is encrypted */
969 	if (ext4_encrypted_inode(dir)) {
970 		err = ext4_get_encryption_info(dir);
971 		if (err < 0) {
972 			brelse(bh);
973 			return err;
974 		}
975 		err = ext4_fname_crypto_alloc_buffer(dir, EXT4_NAME_LEN,
976 						     &fname_crypto_str);
977 		if (err < 0) {
978 			brelse(bh);
979 			return err;
980 		}
981 	}
982 #endif
983 	for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
984 		if (ext4_check_dir_entry(dir, NULL, de, bh,
985 				bh->b_data, bh->b_size,
986 				(block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
987 					 + ((char *)de - bh->b_data))) {
988 			/* silently ignore the rest of the block */
989 			break;
990 		}
991 		ext4fs_dirhash(de->name, de->name_len, hinfo);
992 		if ((hinfo->hash < start_hash) ||
993 		    ((hinfo->hash == start_hash) &&
994 		     (hinfo->minor_hash < start_minor_hash)))
995 			continue;
996 		if (de->inode == 0)
997 			continue;
998 		if (!ext4_encrypted_inode(dir)) {
999 			tmp_str.name = de->name;
1000 			tmp_str.len = de->name_len;
1001 			err = ext4_htree_store_dirent(dir_file,
1002 				   hinfo->hash, hinfo->minor_hash, de,
1003 				   &tmp_str);
1004 		} else {
1005 			int save_len = fname_crypto_str.len;
1006 
1007 			/* Directory is encrypted */
1008 			err = ext4_fname_disk_to_usr(dir, hinfo, de,
1009 						     &fname_crypto_str);
1010 			if (err < 0) {
1011 				count = err;
1012 				goto errout;
1013 			}
1014 			err = ext4_htree_store_dirent(dir_file,
1015 				   hinfo->hash, hinfo->minor_hash, de,
1016 					&fname_crypto_str);
1017 			fname_crypto_str.len = save_len;
1018 		}
1019 		if (err != 0) {
1020 			count = err;
1021 			goto errout;
1022 		}
1023 		count++;
1024 	}
1025 errout:
1026 	brelse(bh);
1027 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1028 	ext4_fname_crypto_free_buffer(&fname_crypto_str);
1029 #endif
1030 	return count;
1031 }
1032 
1033 
1034 /*
1035  * This function fills a red-black tree with information from a
1036  * directory.  We start scanning the directory in hash order, starting
1037  * at start_hash and start_minor_hash.
1038  *
1039  * This function returns the number of entries inserted into the tree,
1040  * or a negative error code.
1041  */
1042 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1043 			 __u32 start_minor_hash, __u32 *next_hash)
1044 {
1045 	struct dx_hash_info hinfo;
1046 	struct ext4_dir_entry_2 *de;
1047 	struct dx_frame frames[2], *frame;
1048 	struct inode *dir;
1049 	ext4_lblk_t block;
1050 	int count = 0;
1051 	int ret, err;
1052 	__u32 hashval;
1053 	struct ext4_str tmp_str;
1054 
1055 	dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
1056 		       start_hash, start_minor_hash));
1057 	dir = file_inode(dir_file);
1058 	if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
1059 		hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1060 		if (hinfo.hash_version <= DX_HASH_TEA)
1061 			hinfo.hash_version +=
1062 				EXT4_SB(dir->i_sb)->s_hash_unsigned;
1063 		hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1064 		if (ext4_has_inline_data(dir)) {
1065 			int has_inline_data = 1;
1066 			count = htree_inlinedir_to_tree(dir_file, dir, 0,
1067 							&hinfo, start_hash,
1068 							start_minor_hash,
1069 							&has_inline_data);
1070 			if (has_inline_data) {
1071 				*next_hash = ~0;
1072 				return count;
1073 			}
1074 		}
1075 		count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
1076 					       start_hash, start_minor_hash);
1077 		*next_hash = ~0;
1078 		return count;
1079 	}
1080 	hinfo.hash = start_hash;
1081 	hinfo.minor_hash = 0;
1082 	frame = dx_probe(NULL, dir, &hinfo, frames);
1083 	if (IS_ERR(frame))
1084 		return PTR_ERR(frame);
1085 
1086 	/* Add '.' and '..' from the htree header */
1087 	if (!start_hash && !start_minor_hash) {
1088 		de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1089 		tmp_str.name = de->name;
1090 		tmp_str.len = de->name_len;
1091 		err = ext4_htree_store_dirent(dir_file, 0, 0,
1092 					      de, &tmp_str);
1093 		if (err != 0)
1094 			goto errout;
1095 		count++;
1096 	}
1097 	if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
1098 		de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1099 		de = ext4_next_entry(de, dir->i_sb->s_blocksize);
1100 		tmp_str.name = de->name;
1101 		tmp_str.len = de->name_len;
1102 		err = ext4_htree_store_dirent(dir_file, 2, 0,
1103 					      de, &tmp_str);
1104 		if (err != 0)
1105 			goto errout;
1106 		count++;
1107 	}
1108 
1109 	while (1) {
1110 		if (fatal_signal_pending(current)) {
1111 			err = -ERESTARTSYS;
1112 			goto errout;
1113 		}
1114 		cond_resched();
1115 		block = dx_get_block(frame->at);
1116 		ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
1117 					     start_hash, start_minor_hash);
1118 		if (ret < 0) {
1119 			err = ret;
1120 			goto errout;
1121 		}
1122 		count += ret;
1123 		hashval = ~0;
1124 		ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
1125 					    frame, frames, &hashval);
1126 		*next_hash = hashval;
1127 		if (ret < 0) {
1128 			err = ret;
1129 			goto errout;
1130 		}
1131 		/*
1132 		 * Stop if:  (a) there are no more entries, or
1133 		 * (b) we have inserted at least one entry and the
1134 		 * next hash value is not a continuation
1135 		 */
1136 		if ((ret == 0) ||
1137 		    (count && ((hashval & 1) == 0)))
1138 			break;
1139 	}
1140 	dx_release(frames);
1141 	dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
1142 		       "next hash: %x\n", count, *next_hash));
1143 	return count;
1144 errout:
1145 	dx_release(frames);
1146 	return (err);
1147 }
1148 
1149 static inline int search_dirblock(struct buffer_head *bh,
1150 				  struct inode *dir,
1151 				  struct ext4_filename *fname,
1152 				  const struct qstr *d_name,
1153 				  unsigned int offset,
1154 				  struct ext4_dir_entry_2 **res_dir)
1155 {
1156 	return ext4_search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
1157 			       fname, d_name, offset, res_dir);
1158 }
1159 
1160 /*
1161  * Directory block splitting, compacting
1162  */
1163 
1164 /*
1165  * Create map of hash values, offsets, and sizes, stored at end of block.
1166  * Returns number of entries mapped.
1167  */
1168 static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
1169 		       unsigned blocksize, struct dx_hash_info *hinfo,
1170 		       struct dx_map_entry *map_tail)
1171 {
1172 	int count = 0;
1173 	char *base = (char *) de;
1174 	struct dx_hash_info h = *hinfo;
1175 
1176 	while ((char *) de < base + blocksize) {
1177 		if (de->name_len && de->inode) {
1178 			ext4fs_dirhash(de->name, de->name_len, &h);
1179 			map_tail--;
1180 			map_tail->hash = h.hash;
1181 			map_tail->offs = ((char *) de - base)>>2;
1182 			map_tail->size = le16_to_cpu(de->rec_len);
1183 			count++;
1184 			cond_resched();
1185 		}
1186 		/* XXX: do we need to check rec_len == 0 case? -Chris */
1187 		de = ext4_next_entry(de, blocksize);
1188 	}
1189 	return count;
1190 }
1191 
1192 /* Sort map by hash value */
1193 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
1194 {
1195 	struct dx_map_entry *p, *q, *top = map + count - 1;
1196 	int more;
1197 	/* Combsort until bubble sort doesn't suck */
1198 	while (count > 2) {
1199 		count = count*10/13;
1200 		if (count - 9 < 2) /* 9, 10 -> 11 */
1201 			count = 11;
1202 		for (p = top, q = p - count; q >= map; p--, q--)
1203 			if (p->hash < q->hash)
1204 				swap(*p, *q);
1205 	}
1206 	/* Garden variety bubble sort */
1207 	do {
1208 		more = 0;
1209 		q = top;
1210 		while (q-- > map) {
1211 			if (q[1].hash >= q[0].hash)
1212 				continue;
1213 			swap(*(q+1), *q);
1214 			more = 1;
1215 		}
1216 	} while(more);
1217 }
1218 
1219 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
1220 {
1221 	struct dx_entry *entries = frame->entries;
1222 	struct dx_entry *old = frame->at, *new = old + 1;
1223 	int count = dx_get_count(entries);
1224 
1225 	assert(count < dx_get_limit(entries));
1226 	assert(old < entries + count);
1227 	memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
1228 	dx_set_hash(new, hash);
1229 	dx_set_block(new, block);
1230 	dx_set_count(entries, count + 1);
1231 }
1232 
1233 /*
1234  * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
1235  *
1236  * `len <= EXT4_NAME_LEN' is guaranteed by caller.
1237  * `de != NULL' is guaranteed by caller.
1238  */
1239 static inline int ext4_match(struct ext4_filename *fname,
1240 			     struct ext4_dir_entry_2 *de)
1241 {
1242 	const void *name = fname_name(fname);
1243 	u32 len = fname_len(fname);
1244 
1245 	if (!de->inode)
1246 		return 0;
1247 
1248 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1249 	if (unlikely(!name)) {
1250 		if (fname->usr_fname->name[0] == '_') {
1251 			int ret;
1252 			if (de->name_len < 16)
1253 				return 0;
1254 			ret = memcmp(de->name + de->name_len - 16,
1255 				     fname->crypto_buf.name + 8, 16);
1256 			return (ret == 0) ? 1 : 0;
1257 		}
1258 		name = fname->crypto_buf.name;
1259 		len = fname->crypto_buf.len;
1260 	}
1261 #endif
1262 	if (de->name_len != len)
1263 		return 0;
1264 	return (memcmp(de->name, name, len) == 0) ? 1 : 0;
1265 }
1266 
1267 /*
1268  * Returns 0 if not found, -1 on failure, and 1 on success
1269  */
1270 int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
1271 		    struct inode *dir, struct ext4_filename *fname,
1272 		    const struct qstr *d_name,
1273 		    unsigned int offset, struct ext4_dir_entry_2 **res_dir)
1274 {
1275 	struct ext4_dir_entry_2 * de;
1276 	char * dlimit;
1277 	int de_len;
1278 	int res;
1279 
1280 	de = (struct ext4_dir_entry_2 *)search_buf;
1281 	dlimit = search_buf + buf_size;
1282 	while ((char *) de < dlimit) {
1283 		/* this code is executed quadratically often */
1284 		/* do minimal checking `by hand' */
1285 		if ((char *) de + de->name_len <= dlimit) {
1286 			res = ext4_match(fname, de);
1287 			if (res < 0) {
1288 				res = -1;
1289 				goto return_result;
1290 			}
1291 			if (res > 0) {
1292 				/* found a match - just to be sure, do
1293 				 * a full check */
1294 				if (ext4_check_dir_entry(dir, NULL, de, bh,
1295 						bh->b_data,
1296 						 bh->b_size, offset)) {
1297 					res = -1;
1298 					goto return_result;
1299 				}
1300 				*res_dir = de;
1301 				res = 1;
1302 				goto return_result;
1303 			}
1304 
1305 		}
1306 		/* prevent looping on a bad block */
1307 		de_len = ext4_rec_len_from_disk(de->rec_len,
1308 						dir->i_sb->s_blocksize);
1309 		if (de_len <= 0) {
1310 			res = -1;
1311 			goto return_result;
1312 		}
1313 		offset += de_len;
1314 		de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
1315 	}
1316 
1317 	res = 0;
1318 return_result:
1319 	return res;
1320 }
1321 
1322 static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
1323 			       struct ext4_dir_entry *de)
1324 {
1325 	struct super_block *sb = dir->i_sb;
1326 
1327 	if (!is_dx(dir))
1328 		return 0;
1329 	if (block == 0)
1330 		return 1;
1331 	if (de->inode == 0 &&
1332 	    ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
1333 			sb->s_blocksize)
1334 		return 1;
1335 	return 0;
1336 }
1337 
1338 /*
1339  *	ext4_find_entry()
1340  *
1341  * finds an entry in the specified directory with the wanted name. It
1342  * returns the cache buffer in which the entry was found, and the entry
1343  * itself (as a parameter - res_dir). It does NOT read the inode of the
1344  * entry - you'll have to do that yourself if you want to.
1345  *
1346  * The returned buffer_head has ->b_count elevated.  The caller is expected
1347  * to brelse() it when appropriate.
1348  */
1349 static struct buffer_head * ext4_find_entry (struct inode *dir,
1350 					const struct qstr *d_name,
1351 					struct ext4_dir_entry_2 **res_dir,
1352 					int *inlined)
1353 {
1354 	struct super_block *sb;
1355 	struct buffer_head *bh_use[NAMEI_RA_SIZE];
1356 	struct buffer_head *bh, *ret = NULL;
1357 	ext4_lblk_t start, block, b;
1358 	const u8 *name = d_name->name;
1359 	int ra_max = 0;		/* Number of bh's in the readahead
1360 				   buffer, bh_use[] */
1361 	int ra_ptr = 0;		/* Current index into readahead
1362 				   buffer */
1363 	int num = 0;
1364 	ext4_lblk_t  nblocks;
1365 	int i, namelen, retval;
1366 	struct ext4_filename fname;
1367 
1368 	*res_dir = NULL;
1369 	sb = dir->i_sb;
1370 	namelen = d_name->len;
1371 	if (namelen > EXT4_NAME_LEN)
1372 		return NULL;
1373 
1374 	retval = ext4_fname_setup_filename(dir, d_name, 1, &fname);
1375 	if (retval)
1376 		return ERR_PTR(retval);
1377 
1378 	if (ext4_has_inline_data(dir)) {
1379 		int has_inline_data = 1;
1380 		ret = ext4_find_inline_entry(dir, &fname, d_name, res_dir,
1381 					     &has_inline_data);
1382 		if (has_inline_data) {
1383 			if (inlined)
1384 				*inlined = 1;
1385 			goto cleanup_and_exit;
1386 		}
1387 	}
1388 
1389 	if ((namelen <= 2) && (name[0] == '.') &&
1390 	    (name[1] == '.' || name[1] == '\0')) {
1391 		/*
1392 		 * "." or ".." will only be in the first block
1393 		 * NFS may look up ".."; "." should be handled by the VFS
1394 		 */
1395 		block = start = 0;
1396 		nblocks = 1;
1397 		goto restart;
1398 	}
1399 	if (is_dx(dir)) {
1400 		ret = ext4_dx_find_entry(dir, &fname, res_dir);
1401 		/*
1402 		 * On success, or if the error was file not found,
1403 		 * return.  Otherwise, fall back to doing a search the
1404 		 * old fashioned way.
1405 		 */
1406 		if (!IS_ERR(ret) || PTR_ERR(ret) != ERR_BAD_DX_DIR)
1407 			goto cleanup_and_exit;
1408 		dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
1409 			       "falling back\n"));
1410 	}
1411 	nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1412 	start = EXT4_I(dir)->i_dir_start_lookup;
1413 	if (start >= nblocks)
1414 		start = 0;
1415 	block = start;
1416 restart:
1417 	do {
1418 		/*
1419 		 * We deal with the read-ahead logic here.
1420 		 */
1421 		if (ra_ptr >= ra_max) {
1422 			/* Refill the readahead buffer */
1423 			ra_ptr = 0;
1424 			b = block;
1425 			for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
1426 				/*
1427 				 * Terminate if we reach the end of the
1428 				 * directory and must wrap, or if our
1429 				 * search has finished at this block.
1430 				 */
1431 				if (b >= nblocks || (num && block == start)) {
1432 					bh_use[ra_max] = NULL;
1433 					break;
1434 				}
1435 				num++;
1436 				bh = ext4_getblk(NULL, dir, b++, 0);
1437 				if (IS_ERR(bh)) {
1438 					if (ra_max == 0) {
1439 						ret = bh;
1440 						goto cleanup_and_exit;
1441 					}
1442 					break;
1443 				}
1444 				bh_use[ra_max] = bh;
1445 				if (bh)
1446 					ll_rw_block(READ | REQ_META | REQ_PRIO,
1447 						    1, &bh);
1448 			}
1449 		}
1450 		if ((bh = bh_use[ra_ptr++]) == NULL)
1451 			goto next;
1452 		wait_on_buffer(bh);
1453 		if (!buffer_uptodate(bh)) {
1454 			/* read error, skip block & hope for the best */
1455 			EXT4_ERROR_INODE(dir, "reading directory lblock %lu",
1456 					 (unsigned long) block);
1457 			brelse(bh);
1458 			goto next;
1459 		}
1460 		if (!buffer_verified(bh) &&
1461 		    !is_dx_internal_node(dir, block,
1462 					 (struct ext4_dir_entry *)bh->b_data) &&
1463 		    !ext4_dirent_csum_verify(dir,
1464 				(struct ext4_dir_entry *)bh->b_data)) {
1465 			EXT4_ERROR_INODE(dir, "checksumming directory "
1466 					 "block %lu", (unsigned long)block);
1467 			brelse(bh);
1468 			goto next;
1469 		}
1470 		set_buffer_verified(bh);
1471 		i = search_dirblock(bh, dir, &fname, d_name,
1472 			    block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
1473 		if (i == 1) {
1474 			EXT4_I(dir)->i_dir_start_lookup = block;
1475 			ret = bh;
1476 			goto cleanup_and_exit;
1477 		} else {
1478 			brelse(bh);
1479 			if (i < 0)
1480 				goto cleanup_and_exit;
1481 		}
1482 	next:
1483 		if (++block >= nblocks)
1484 			block = 0;
1485 	} while (block != start);
1486 
1487 	/*
1488 	 * If the directory has grown while we were searching, then
1489 	 * search the last part of the directory before giving up.
1490 	 */
1491 	block = nblocks;
1492 	nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1493 	if (block < nblocks) {
1494 		start = 0;
1495 		goto restart;
1496 	}
1497 
1498 cleanup_and_exit:
1499 	/* Clean up the read-ahead blocks */
1500 	for (; ra_ptr < ra_max; ra_ptr++)
1501 		brelse(bh_use[ra_ptr]);
1502 	ext4_fname_free_filename(&fname);
1503 	return ret;
1504 }
1505 
1506 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
1507 			struct ext4_filename *fname,
1508 			struct ext4_dir_entry_2 **res_dir)
1509 {
1510 	struct super_block * sb = dir->i_sb;
1511 	struct dx_frame frames[2], *frame;
1512 	const struct qstr *d_name = fname->usr_fname;
1513 	struct buffer_head *bh;
1514 	ext4_lblk_t block;
1515 	int retval;
1516 
1517 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1518 	*res_dir = NULL;
1519 #endif
1520 	frame = dx_probe(fname, dir, NULL, frames);
1521 	if (IS_ERR(frame))
1522 		return (struct buffer_head *) frame;
1523 	do {
1524 		block = dx_get_block(frame->at);
1525 		bh = ext4_read_dirblock(dir, block, DIRENT);
1526 		if (IS_ERR(bh))
1527 			goto errout;
1528 
1529 		retval = search_dirblock(bh, dir, fname, d_name,
1530 					 block << EXT4_BLOCK_SIZE_BITS(sb),
1531 					 res_dir);
1532 		if (retval == 1)
1533 			goto success;
1534 		brelse(bh);
1535 		if (retval == -1) {
1536 			bh = ERR_PTR(ERR_BAD_DX_DIR);
1537 			goto errout;
1538 		}
1539 
1540 		/* Check to see if we should continue to search */
1541 		retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame,
1542 					       frames, NULL);
1543 		if (retval < 0) {
1544 			ext4_warning_inode(dir,
1545 				"error %d reading directory index block",
1546 				retval);
1547 			bh = ERR_PTR(retval);
1548 			goto errout;
1549 		}
1550 	} while (retval == 1);
1551 
1552 	bh = NULL;
1553 errout:
1554 	dxtrace(printk(KERN_DEBUG "%s not found\n", d_name->name));
1555 success:
1556 	dx_release(frames);
1557 	return bh;
1558 }
1559 
1560 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
1561 {
1562 	struct inode *inode;
1563 	struct ext4_dir_entry_2 *de;
1564 	struct buffer_head *bh;
1565 
1566        if (ext4_encrypted_inode(dir)) {
1567                int res = ext4_get_encryption_info(dir);
1568 
1569 		/*
1570 		 * This should be a properly defined flag for
1571 		 * dentry->d_flags when we uplift this to the VFS.
1572 		 * d_fsdata is set to (void *) 1 if if the dentry is
1573 		 * created while the directory was encrypted and we
1574 		 * don't have access to the key.
1575 		 */
1576 	       dentry->d_fsdata = NULL;
1577 	       if (ext4_encryption_info(dir))
1578 		       dentry->d_fsdata = (void *) 1;
1579 	       d_set_d_op(dentry, &ext4_encrypted_d_ops);
1580 	       if (res && res != -ENOKEY)
1581 		       return ERR_PTR(res);
1582        }
1583 
1584 	if (dentry->d_name.len > EXT4_NAME_LEN)
1585 		return ERR_PTR(-ENAMETOOLONG);
1586 
1587 	bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
1588 	if (IS_ERR(bh))
1589 		return (struct dentry *) bh;
1590 	inode = NULL;
1591 	if (bh) {
1592 		__u32 ino = le32_to_cpu(de->inode);
1593 		brelse(bh);
1594 		if (!ext4_valid_inum(dir->i_sb, ino)) {
1595 			EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1596 			return ERR_PTR(-EFSCORRUPTED);
1597 		}
1598 		if (unlikely(ino == dir->i_ino)) {
1599 			EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir",
1600 					 dentry);
1601 			return ERR_PTR(-EFSCORRUPTED);
1602 		}
1603 		inode = ext4_iget_normal(dir->i_sb, ino);
1604 		if (inode == ERR_PTR(-ESTALE)) {
1605 			EXT4_ERROR_INODE(dir,
1606 					 "deleted inode referenced: %u",
1607 					 ino);
1608 			return ERR_PTR(-EFSCORRUPTED);
1609 		}
1610 		if (!IS_ERR(inode) && ext4_encrypted_inode(dir) &&
1611 		    (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) &&
1612 		    !ext4_is_child_context_consistent_with_parent(dir,
1613 								  inode)) {
1614 			int nokey = ext4_encrypted_inode(inode) &&
1615 				!ext4_encryption_info(inode);
1616 
1617 			iput(inode);
1618 			if (nokey)
1619 				return ERR_PTR(-ENOKEY);
1620 			ext4_warning(inode->i_sb,
1621 				     "Inconsistent encryption contexts: %lu/%lu",
1622 				     (unsigned long) dir->i_ino,
1623 				     (unsigned long) inode->i_ino);
1624 			return ERR_PTR(-EPERM);
1625 		}
1626 	}
1627 	return d_splice_alias(inode, dentry);
1628 }
1629 
1630 
1631 struct dentry *ext4_get_parent(struct dentry *child)
1632 {
1633 	__u32 ino;
1634 	static const struct qstr dotdot = QSTR_INIT("..", 2);
1635 	struct ext4_dir_entry_2 * de;
1636 	struct buffer_head *bh;
1637 
1638 	bh = ext4_find_entry(d_inode(child), &dotdot, &de, NULL);
1639 	if (IS_ERR(bh))
1640 		return (struct dentry *) bh;
1641 	if (!bh)
1642 		return ERR_PTR(-ENOENT);
1643 	ino = le32_to_cpu(de->inode);
1644 	brelse(bh);
1645 
1646 	if (!ext4_valid_inum(child->d_sb, ino)) {
1647 		EXT4_ERROR_INODE(d_inode(child),
1648 				 "bad parent inode number: %u", ino);
1649 		return ERR_PTR(-EFSCORRUPTED);
1650 	}
1651 
1652 	return d_obtain_alias(ext4_iget_normal(child->d_sb, ino));
1653 }
1654 
1655 /*
1656  * Move count entries from end of map between two memory locations.
1657  * Returns pointer to last entry moved.
1658  */
1659 static struct ext4_dir_entry_2 *
1660 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1661 		unsigned blocksize)
1662 {
1663 	unsigned rec_len = 0;
1664 
1665 	while (count--) {
1666 		struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1667 						(from + (map->offs<<2));
1668 		rec_len = EXT4_DIR_REC_LEN(de->name_len);
1669 		memcpy (to, de, rec_len);
1670 		((struct ext4_dir_entry_2 *) to)->rec_len =
1671 				ext4_rec_len_to_disk(rec_len, blocksize);
1672 		de->inode = 0;
1673 		map++;
1674 		to += rec_len;
1675 	}
1676 	return (struct ext4_dir_entry_2 *) (to - rec_len);
1677 }
1678 
1679 /*
1680  * Compact each dir entry in the range to the minimal rec_len.
1681  * Returns pointer to last entry in range.
1682  */
1683 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1684 {
1685 	struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1686 	unsigned rec_len = 0;
1687 
1688 	prev = to = de;
1689 	while ((char*)de < base + blocksize) {
1690 		next = ext4_next_entry(de, blocksize);
1691 		if (de->inode && de->name_len) {
1692 			rec_len = EXT4_DIR_REC_LEN(de->name_len);
1693 			if (de > to)
1694 				memmove(to, de, rec_len);
1695 			to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1696 			prev = to;
1697 			to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1698 		}
1699 		de = next;
1700 	}
1701 	return prev;
1702 }
1703 
1704 /*
1705  * Split a full leaf block to make room for a new dir entry.
1706  * Allocate a new block, and move entries so that they are approx. equally full.
1707  * Returns pointer to de in block into which the new entry will be inserted.
1708  */
1709 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1710 			struct buffer_head **bh,struct dx_frame *frame,
1711 			struct dx_hash_info *hinfo)
1712 {
1713 	unsigned blocksize = dir->i_sb->s_blocksize;
1714 	unsigned count, continued;
1715 	struct buffer_head *bh2;
1716 	ext4_lblk_t newblock;
1717 	u32 hash2;
1718 	struct dx_map_entry *map;
1719 	char *data1 = (*bh)->b_data, *data2;
1720 	unsigned split, move, size;
1721 	struct ext4_dir_entry_2 *de = NULL, *de2;
1722 	struct ext4_dir_entry_tail *t;
1723 	int	csum_size = 0;
1724 	int	err = 0, i;
1725 
1726 	if (ext4_has_metadata_csum(dir->i_sb))
1727 		csum_size = sizeof(struct ext4_dir_entry_tail);
1728 
1729 	bh2 = ext4_append(handle, dir, &newblock);
1730 	if (IS_ERR(bh2)) {
1731 		brelse(*bh);
1732 		*bh = NULL;
1733 		return (struct ext4_dir_entry_2 *) bh2;
1734 	}
1735 
1736 	BUFFER_TRACE(*bh, "get_write_access");
1737 	err = ext4_journal_get_write_access(handle, *bh);
1738 	if (err)
1739 		goto journal_error;
1740 
1741 	BUFFER_TRACE(frame->bh, "get_write_access");
1742 	err = ext4_journal_get_write_access(handle, frame->bh);
1743 	if (err)
1744 		goto journal_error;
1745 
1746 	data2 = bh2->b_data;
1747 
1748 	/* create map in the end of data2 block */
1749 	map = (struct dx_map_entry *) (data2 + blocksize);
1750 	count = dx_make_map(dir, (struct ext4_dir_entry_2 *) data1,
1751 			     blocksize, hinfo, map);
1752 	map -= count;
1753 	dx_sort_map(map, count);
1754 	/* Split the existing block in the middle, size-wise */
1755 	size = 0;
1756 	move = 0;
1757 	for (i = count-1; i >= 0; i--) {
1758 		/* is more than half of this entry in 2nd half of the block? */
1759 		if (size + map[i].size/2 > blocksize/2)
1760 			break;
1761 		size += map[i].size;
1762 		move++;
1763 	}
1764 	/* map index at which we will split */
1765 	split = count - move;
1766 	hash2 = map[split].hash;
1767 	continued = hash2 == map[split - 1].hash;
1768 	dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1769 			(unsigned long)dx_get_block(frame->at),
1770 					hash2, split, count-split));
1771 
1772 	/* Fancy dance to stay within two buffers */
1773 	de2 = dx_move_dirents(data1, data2, map + split, count - split,
1774 			      blocksize);
1775 	de = dx_pack_dirents(data1, blocksize);
1776 	de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
1777 					   (char *) de,
1778 					   blocksize);
1779 	de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
1780 					    (char *) de2,
1781 					    blocksize);
1782 	if (csum_size) {
1783 		t = EXT4_DIRENT_TAIL(data2, blocksize);
1784 		initialize_dirent_tail(t, blocksize);
1785 
1786 		t = EXT4_DIRENT_TAIL(data1, blocksize);
1787 		initialize_dirent_tail(t, blocksize);
1788 	}
1789 
1790 	dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1,
1791 			blocksize, 1));
1792 	dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2,
1793 			blocksize, 1));
1794 
1795 	/* Which block gets the new entry? */
1796 	if (hinfo->hash >= hash2) {
1797 		swap(*bh, bh2);
1798 		de = de2;
1799 	}
1800 	dx_insert_block(frame, hash2 + continued, newblock);
1801 	err = ext4_handle_dirty_dirent_node(handle, dir, bh2);
1802 	if (err)
1803 		goto journal_error;
1804 	err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
1805 	if (err)
1806 		goto journal_error;
1807 	brelse(bh2);
1808 	dxtrace(dx_show_index("frame", frame->entries));
1809 	return de;
1810 
1811 journal_error:
1812 	brelse(*bh);
1813 	brelse(bh2);
1814 	*bh = NULL;
1815 	ext4_std_error(dir->i_sb, err);
1816 	return ERR_PTR(err);
1817 }
1818 
1819 int ext4_find_dest_de(struct inode *dir, struct inode *inode,
1820 		      struct buffer_head *bh,
1821 		      void *buf, int buf_size,
1822 		      struct ext4_filename *fname,
1823 		      struct ext4_dir_entry_2 **dest_de)
1824 {
1825 	struct ext4_dir_entry_2 *de;
1826 	unsigned short reclen = EXT4_DIR_REC_LEN(fname_len(fname));
1827 	int nlen, rlen;
1828 	unsigned int offset = 0;
1829 	char *top;
1830 	int res;
1831 
1832 	de = (struct ext4_dir_entry_2 *)buf;
1833 	top = buf + buf_size - reclen;
1834 	while ((char *) de <= top) {
1835 		if (ext4_check_dir_entry(dir, NULL, de, bh,
1836 					 buf, buf_size, offset)) {
1837 			res = -EFSCORRUPTED;
1838 			goto return_result;
1839 		}
1840 		/* Provide crypto context and crypto buffer to ext4 match */
1841 		res = ext4_match(fname, de);
1842 		if (res < 0)
1843 			goto return_result;
1844 		if (res > 0) {
1845 			res = -EEXIST;
1846 			goto return_result;
1847 		}
1848 		nlen = EXT4_DIR_REC_LEN(de->name_len);
1849 		rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1850 		if ((de->inode ? rlen - nlen : rlen) >= reclen)
1851 			break;
1852 		de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1853 		offset += rlen;
1854 	}
1855 
1856 	if ((char *) de > top)
1857 		res = -ENOSPC;
1858 	else {
1859 		*dest_de = de;
1860 		res = 0;
1861 	}
1862 return_result:
1863 	return res;
1864 }
1865 
1866 int ext4_insert_dentry(struct inode *dir,
1867 		       struct inode *inode,
1868 		       struct ext4_dir_entry_2 *de,
1869 		       int buf_size,
1870 		       struct ext4_filename *fname)
1871 {
1872 
1873 	int nlen, rlen;
1874 
1875 	nlen = EXT4_DIR_REC_LEN(de->name_len);
1876 	rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
1877 	if (de->inode) {
1878 		struct ext4_dir_entry_2 *de1 =
1879 			(struct ext4_dir_entry_2 *)((char *)de + nlen);
1880 		de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
1881 		de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
1882 		de = de1;
1883 	}
1884 	de->file_type = EXT4_FT_UNKNOWN;
1885 	de->inode = cpu_to_le32(inode->i_ino);
1886 	ext4_set_de_type(inode->i_sb, de, inode->i_mode);
1887 	de->name_len = fname_len(fname);
1888 	memcpy(de->name, fname_name(fname), fname_len(fname));
1889 	return 0;
1890 }
1891 
1892 /*
1893  * Add a new entry into a directory (leaf) block.  If de is non-NULL,
1894  * it points to a directory entry which is guaranteed to be large
1895  * enough for new directory entry.  If de is NULL, then
1896  * add_dirent_to_buf will attempt search the directory block for
1897  * space.  It will return -ENOSPC if no space is available, and -EIO
1898  * and -EEXIST if directory entry already exists.
1899  */
1900 static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
1901 			     struct inode *dir,
1902 			     struct inode *inode, struct ext4_dir_entry_2 *de,
1903 			     struct buffer_head *bh)
1904 {
1905 	unsigned int	blocksize = dir->i_sb->s_blocksize;
1906 	int		csum_size = 0;
1907 	int		err;
1908 
1909 	if (ext4_has_metadata_csum(inode->i_sb))
1910 		csum_size = sizeof(struct ext4_dir_entry_tail);
1911 
1912 	if (!de) {
1913 		err = ext4_find_dest_de(dir, inode, bh, bh->b_data,
1914 					blocksize - csum_size, fname, &de);
1915 		if (err)
1916 			return err;
1917 	}
1918 	BUFFER_TRACE(bh, "get_write_access");
1919 	err = ext4_journal_get_write_access(handle, bh);
1920 	if (err) {
1921 		ext4_std_error(dir->i_sb, err);
1922 		return err;
1923 	}
1924 
1925 	/* By now the buffer is marked for journaling. Due to crypto operations,
1926 	 * the following function call may fail */
1927 	err = ext4_insert_dentry(dir, inode, de, blocksize, fname);
1928 	if (err < 0)
1929 		return err;
1930 
1931 	/*
1932 	 * XXX shouldn't update any times until successful
1933 	 * completion of syscall, but too many callers depend
1934 	 * on this.
1935 	 *
1936 	 * XXX similarly, too many callers depend on
1937 	 * ext4_new_inode() setting the times, but error
1938 	 * recovery deletes the inode, so the worst that can
1939 	 * happen is that the times are slightly out of date
1940 	 * and/or different from the directory change time.
1941 	 */
1942 	dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
1943 	ext4_update_dx_flag(dir);
1944 	dir->i_version++;
1945 	ext4_mark_inode_dirty(handle, dir);
1946 	BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1947 	err = ext4_handle_dirty_dirent_node(handle, dir, bh);
1948 	if (err)
1949 		ext4_std_error(dir->i_sb, err);
1950 	return 0;
1951 }
1952 
1953 /*
1954  * This converts a one block unindexed directory to a 3 block indexed
1955  * directory, and adds the dentry to the indexed directory.
1956  */
1957 static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
1958 			    struct inode *dir,
1959 			    struct inode *inode, struct buffer_head *bh)
1960 {
1961 	struct buffer_head *bh2;
1962 	struct dx_root	*root;
1963 	struct dx_frame	frames[2], *frame;
1964 	struct dx_entry *entries;
1965 	struct ext4_dir_entry_2	*de, *de2;
1966 	struct ext4_dir_entry_tail *t;
1967 	char		*data1, *top;
1968 	unsigned	len;
1969 	int		retval;
1970 	unsigned	blocksize;
1971 	ext4_lblk_t  block;
1972 	struct fake_dirent *fde;
1973 	int csum_size = 0;
1974 
1975 	if (ext4_has_metadata_csum(inode->i_sb))
1976 		csum_size = sizeof(struct ext4_dir_entry_tail);
1977 
1978 	blocksize =  dir->i_sb->s_blocksize;
1979 	dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
1980 	BUFFER_TRACE(bh, "get_write_access");
1981 	retval = ext4_journal_get_write_access(handle, bh);
1982 	if (retval) {
1983 		ext4_std_error(dir->i_sb, retval);
1984 		brelse(bh);
1985 		return retval;
1986 	}
1987 	root = (struct dx_root *) bh->b_data;
1988 
1989 	/* The 0th block becomes the root, move the dirents out */
1990 	fde = &root->dotdot;
1991 	de = (struct ext4_dir_entry_2 *)((char *)fde +
1992 		ext4_rec_len_from_disk(fde->rec_len, blocksize));
1993 	if ((char *) de >= (((char *) root) + blocksize)) {
1994 		EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
1995 		brelse(bh);
1996 		return -EFSCORRUPTED;
1997 	}
1998 	len = ((char *) root) + (blocksize - csum_size) - (char *) de;
1999 
2000 	/* Allocate new block for the 0th block's dirents */
2001 	bh2 = ext4_append(handle, dir, &block);
2002 	if (IS_ERR(bh2)) {
2003 		brelse(bh);
2004 		return PTR_ERR(bh2);
2005 	}
2006 	ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
2007 	data1 = bh2->b_data;
2008 
2009 	memcpy (data1, de, len);
2010 	de = (struct ext4_dir_entry_2 *) data1;
2011 	top = data1 + len;
2012 	while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
2013 		de = de2;
2014 	de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
2015 					   (char *) de,
2016 					   blocksize);
2017 
2018 	if (csum_size) {
2019 		t = EXT4_DIRENT_TAIL(data1, blocksize);
2020 		initialize_dirent_tail(t, blocksize);
2021 	}
2022 
2023 	/* Initialize the root; the dot dirents already exist */
2024 	de = (struct ext4_dir_entry_2 *) (&root->dotdot);
2025 	de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
2026 					   blocksize);
2027 	memset (&root->info, 0, sizeof(root->info));
2028 	root->info.info_length = sizeof(root->info);
2029 	root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
2030 	entries = root->entries;
2031 	dx_set_block(entries, 1);
2032 	dx_set_count(entries, 1);
2033 	dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
2034 
2035 	/* Initialize as for dx_probe */
2036 	fname->hinfo.hash_version = root->info.hash_version;
2037 	if (fname->hinfo.hash_version <= DX_HASH_TEA)
2038 		fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
2039 	fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
2040 	ext4fs_dirhash(fname_name(fname), fname_len(fname), &fname->hinfo);
2041 
2042 	memset(frames, 0, sizeof(frames));
2043 	frame = frames;
2044 	frame->entries = entries;
2045 	frame->at = entries;
2046 	frame->bh = bh;
2047 	bh = bh2;
2048 
2049 	retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
2050 	if (retval)
2051 		goto out_frames;
2052 	retval = ext4_handle_dirty_dirent_node(handle, dir, bh);
2053 	if (retval)
2054 		goto out_frames;
2055 
2056 	de = do_split(handle,dir, &bh, frame, &fname->hinfo);
2057 	if (IS_ERR(de)) {
2058 		retval = PTR_ERR(de);
2059 		goto out_frames;
2060 	}
2061 	dx_release(frames);
2062 
2063 	retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
2064 	brelse(bh);
2065 	return retval;
2066 out_frames:
2067 	/*
2068 	 * Even if the block split failed, we have to properly write
2069 	 * out all the changes we did so far. Otherwise we can end up
2070 	 * with corrupted filesystem.
2071 	 */
2072 	ext4_mark_inode_dirty(handle, dir);
2073 	dx_release(frames);
2074 	return retval;
2075 }
2076 
2077 /*
2078  *	ext4_add_entry()
2079  *
2080  * adds a file entry to the specified directory, using the same
2081  * semantics as ext4_find_entry(). It returns NULL if it failed.
2082  *
2083  * NOTE!! The inode part of 'de' is left at 0 - which means you
2084  * may not sleep between calling this and putting something into
2085  * the entry, as someone else might have used it while you slept.
2086  */
2087 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
2088 			  struct inode *inode)
2089 {
2090 	struct inode *dir = d_inode(dentry->d_parent);
2091 	struct buffer_head *bh = NULL;
2092 	struct ext4_dir_entry_2 *de;
2093 	struct ext4_dir_entry_tail *t;
2094 	struct super_block *sb;
2095 	struct ext4_filename fname;
2096 	int	retval;
2097 	int	dx_fallback=0;
2098 	unsigned blocksize;
2099 	ext4_lblk_t block, blocks;
2100 	int	csum_size = 0;
2101 
2102 	if (ext4_has_metadata_csum(inode->i_sb))
2103 		csum_size = sizeof(struct ext4_dir_entry_tail);
2104 
2105 	sb = dir->i_sb;
2106 	blocksize = sb->s_blocksize;
2107 	if (!dentry->d_name.len)
2108 		return -EINVAL;
2109 
2110 	retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname);
2111 	if (retval)
2112 		return retval;
2113 
2114 	if (ext4_has_inline_data(dir)) {
2115 		retval = ext4_try_add_inline_entry(handle, &fname, dir, inode);
2116 		if (retval < 0)
2117 			goto out;
2118 		if (retval == 1) {
2119 			retval = 0;
2120 			goto out;
2121 		}
2122 	}
2123 
2124 	if (is_dx(dir)) {
2125 		retval = ext4_dx_add_entry(handle, &fname, dir, inode);
2126 		if (!retval || (retval != ERR_BAD_DX_DIR))
2127 			goto out;
2128 		ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
2129 		dx_fallback++;
2130 		ext4_mark_inode_dirty(handle, dir);
2131 	}
2132 	blocks = dir->i_size >> sb->s_blocksize_bits;
2133 	for (block = 0; block < blocks; block++) {
2134 		bh = ext4_read_dirblock(dir, block, DIRENT);
2135 		if (IS_ERR(bh)) {
2136 			retval = PTR_ERR(bh);
2137 			bh = NULL;
2138 			goto out;
2139 		}
2140 		retval = add_dirent_to_buf(handle, &fname, dir, inode,
2141 					   NULL, bh);
2142 		if (retval != -ENOSPC)
2143 			goto out;
2144 
2145 		if (blocks == 1 && !dx_fallback &&
2146 		    ext4_has_feature_dir_index(sb)) {
2147 			retval = make_indexed_dir(handle, &fname, dir,
2148 						  inode, bh);
2149 			bh = NULL; /* make_indexed_dir releases bh */
2150 			goto out;
2151 		}
2152 		brelse(bh);
2153 	}
2154 	bh = ext4_append(handle, dir, &block);
2155 	if (IS_ERR(bh)) {
2156 		retval = PTR_ERR(bh);
2157 		bh = NULL;
2158 		goto out;
2159 	}
2160 	de = (struct ext4_dir_entry_2 *) bh->b_data;
2161 	de->inode = 0;
2162 	de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
2163 
2164 	if (csum_size) {
2165 		t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
2166 		initialize_dirent_tail(t, blocksize);
2167 	}
2168 
2169 	retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh);
2170 out:
2171 	ext4_fname_free_filename(&fname);
2172 	brelse(bh);
2173 	if (retval == 0)
2174 		ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
2175 	return retval;
2176 }
2177 
2178 /*
2179  * Returns 0 for success, or a negative error value
2180  */
2181 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
2182 			     struct inode *dir, struct inode *inode)
2183 {
2184 	struct dx_frame frames[2], *frame;
2185 	struct dx_entry *entries, *at;
2186 	struct buffer_head *bh;
2187 	struct super_block *sb = dir->i_sb;
2188 	struct ext4_dir_entry_2 *de;
2189 	int err;
2190 
2191 	frame = dx_probe(fname, dir, NULL, frames);
2192 	if (IS_ERR(frame))
2193 		return PTR_ERR(frame);
2194 	entries = frame->entries;
2195 	at = frame->at;
2196 	bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT);
2197 	if (IS_ERR(bh)) {
2198 		err = PTR_ERR(bh);
2199 		bh = NULL;
2200 		goto cleanup;
2201 	}
2202 
2203 	BUFFER_TRACE(bh, "get_write_access");
2204 	err = ext4_journal_get_write_access(handle, bh);
2205 	if (err)
2206 		goto journal_error;
2207 
2208 	err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh);
2209 	if (err != -ENOSPC)
2210 		goto cleanup;
2211 
2212 	/* Block full, should compress but for now just split */
2213 	dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
2214 		       dx_get_count(entries), dx_get_limit(entries)));
2215 	/* Need to split index? */
2216 	if (dx_get_count(entries) == dx_get_limit(entries)) {
2217 		ext4_lblk_t newblock;
2218 		unsigned icount = dx_get_count(entries);
2219 		int levels = frame - frames;
2220 		struct dx_entry *entries2;
2221 		struct dx_node *node2;
2222 		struct buffer_head *bh2;
2223 
2224 		if (levels && (dx_get_count(frames->entries) ==
2225 			       dx_get_limit(frames->entries))) {
2226 			ext4_warning_inode(dir, "Directory index full!");
2227 			err = -ENOSPC;
2228 			goto cleanup;
2229 		}
2230 		bh2 = ext4_append(handle, dir, &newblock);
2231 		if (IS_ERR(bh2)) {
2232 			err = PTR_ERR(bh2);
2233 			goto cleanup;
2234 		}
2235 		node2 = (struct dx_node *)(bh2->b_data);
2236 		entries2 = node2->entries;
2237 		memset(&node2->fake, 0, sizeof(struct fake_dirent));
2238 		node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
2239 							   sb->s_blocksize);
2240 		BUFFER_TRACE(frame->bh, "get_write_access");
2241 		err = ext4_journal_get_write_access(handle, frame->bh);
2242 		if (err)
2243 			goto journal_error;
2244 		if (levels) {
2245 			unsigned icount1 = icount/2, icount2 = icount - icount1;
2246 			unsigned hash2 = dx_get_hash(entries + icount1);
2247 			dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
2248 				       icount1, icount2));
2249 
2250 			BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
2251 			err = ext4_journal_get_write_access(handle,
2252 							     frames[0].bh);
2253 			if (err)
2254 				goto journal_error;
2255 
2256 			memcpy((char *) entries2, (char *) (entries + icount1),
2257 			       icount2 * sizeof(struct dx_entry));
2258 			dx_set_count(entries, icount1);
2259 			dx_set_count(entries2, icount2);
2260 			dx_set_limit(entries2, dx_node_limit(dir));
2261 
2262 			/* Which index block gets the new entry? */
2263 			if (at - entries >= icount1) {
2264 				frame->at = at = at - entries - icount1 + entries2;
2265 				frame->entries = entries = entries2;
2266 				swap(frame->bh, bh2);
2267 			}
2268 			dx_insert_block(frames + 0, hash2, newblock);
2269 			dxtrace(dx_show_index("node", frames[1].entries));
2270 			dxtrace(dx_show_index("node",
2271 			       ((struct dx_node *) bh2->b_data)->entries));
2272 			err = ext4_handle_dirty_dx_node(handle, dir, bh2);
2273 			if (err)
2274 				goto journal_error;
2275 			brelse (bh2);
2276 		} else {
2277 			dxtrace(printk(KERN_DEBUG
2278 				       "Creating second level index...\n"));
2279 			memcpy((char *) entries2, (char *) entries,
2280 			       icount * sizeof(struct dx_entry));
2281 			dx_set_limit(entries2, dx_node_limit(dir));
2282 
2283 			/* Set up root */
2284 			dx_set_count(entries, 1);
2285 			dx_set_block(entries + 0, newblock);
2286 			((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
2287 
2288 			/* Add new access path frame */
2289 			frame = frames + 1;
2290 			frame->at = at = at - entries + entries2;
2291 			frame->entries = entries = entries2;
2292 			frame->bh = bh2;
2293 			err = ext4_journal_get_write_access(handle,
2294 							     frame->bh);
2295 			if (err)
2296 				goto journal_error;
2297 		}
2298 		err = ext4_handle_dirty_dx_node(handle, dir, frames[0].bh);
2299 		if (err) {
2300 			ext4_std_error(inode->i_sb, err);
2301 			goto cleanup;
2302 		}
2303 	}
2304 	de = do_split(handle, dir, &bh, frame, &fname->hinfo);
2305 	if (IS_ERR(de)) {
2306 		err = PTR_ERR(de);
2307 		goto cleanup;
2308 	}
2309 	err = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
2310 	goto cleanup;
2311 
2312 journal_error:
2313 	ext4_std_error(dir->i_sb, err);
2314 cleanup:
2315 	brelse(bh);
2316 	dx_release(frames);
2317 	return err;
2318 }
2319 
2320 /*
2321  * ext4_generic_delete_entry deletes a directory entry by merging it
2322  * with the previous entry
2323  */
2324 int ext4_generic_delete_entry(handle_t *handle,
2325 			      struct inode *dir,
2326 			      struct ext4_dir_entry_2 *de_del,
2327 			      struct buffer_head *bh,
2328 			      void *entry_buf,
2329 			      int buf_size,
2330 			      int csum_size)
2331 {
2332 	struct ext4_dir_entry_2 *de, *pde;
2333 	unsigned int blocksize = dir->i_sb->s_blocksize;
2334 	int i;
2335 
2336 	i = 0;
2337 	pde = NULL;
2338 	de = (struct ext4_dir_entry_2 *)entry_buf;
2339 	while (i < buf_size - csum_size) {
2340 		if (ext4_check_dir_entry(dir, NULL, de, bh,
2341 					 bh->b_data, bh->b_size, i))
2342 			return -EFSCORRUPTED;
2343 		if (de == de_del)  {
2344 			if (pde)
2345 				pde->rec_len = ext4_rec_len_to_disk(
2346 					ext4_rec_len_from_disk(pde->rec_len,
2347 							       blocksize) +
2348 					ext4_rec_len_from_disk(de->rec_len,
2349 							       blocksize),
2350 					blocksize);
2351 			else
2352 				de->inode = 0;
2353 			dir->i_version++;
2354 			return 0;
2355 		}
2356 		i += ext4_rec_len_from_disk(de->rec_len, blocksize);
2357 		pde = de;
2358 		de = ext4_next_entry(de, blocksize);
2359 	}
2360 	return -ENOENT;
2361 }
2362 
2363 static int ext4_delete_entry(handle_t *handle,
2364 			     struct inode *dir,
2365 			     struct ext4_dir_entry_2 *de_del,
2366 			     struct buffer_head *bh)
2367 {
2368 	int err, csum_size = 0;
2369 
2370 	if (ext4_has_inline_data(dir)) {
2371 		int has_inline_data = 1;
2372 		err = ext4_delete_inline_entry(handle, dir, de_del, bh,
2373 					       &has_inline_data);
2374 		if (has_inline_data)
2375 			return err;
2376 	}
2377 
2378 	if (ext4_has_metadata_csum(dir->i_sb))
2379 		csum_size = sizeof(struct ext4_dir_entry_tail);
2380 
2381 	BUFFER_TRACE(bh, "get_write_access");
2382 	err = ext4_journal_get_write_access(handle, bh);
2383 	if (unlikely(err))
2384 		goto out;
2385 
2386 	err = ext4_generic_delete_entry(handle, dir, de_del,
2387 					bh, bh->b_data,
2388 					dir->i_sb->s_blocksize, csum_size);
2389 	if (err)
2390 		goto out;
2391 
2392 	BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2393 	err = ext4_handle_dirty_dirent_node(handle, dir, bh);
2394 	if (unlikely(err))
2395 		goto out;
2396 
2397 	return 0;
2398 out:
2399 	if (err != -ENOENT)
2400 		ext4_std_error(dir->i_sb, err);
2401 	return err;
2402 }
2403 
2404 /*
2405  * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
2406  * since this indicates that nlinks count was previously 1.
2407  */
2408 static void ext4_inc_count(handle_t *handle, struct inode *inode)
2409 {
2410 	inc_nlink(inode);
2411 	if (is_dx(inode) && inode->i_nlink > 1) {
2412 		/* limit is 16-bit i_links_count */
2413 		if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
2414 			set_nlink(inode, 1);
2415 			ext4_set_feature_dir_nlink(inode->i_sb);
2416 		}
2417 	}
2418 }
2419 
2420 /*
2421  * If a directory had nlink == 1, then we should let it be 1. This indicates
2422  * directory has >EXT4_LINK_MAX subdirs.
2423  */
2424 static void ext4_dec_count(handle_t *handle, struct inode *inode)
2425 {
2426 	if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2427 		drop_nlink(inode);
2428 }
2429 
2430 
2431 static int ext4_add_nondir(handle_t *handle,
2432 		struct dentry *dentry, struct inode *inode)
2433 {
2434 	int err = ext4_add_entry(handle, dentry, inode);
2435 	if (!err) {
2436 		ext4_mark_inode_dirty(handle, inode);
2437 		unlock_new_inode(inode);
2438 		d_instantiate(dentry, inode);
2439 		return 0;
2440 	}
2441 	drop_nlink(inode);
2442 	unlock_new_inode(inode);
2443 	iput(inode);
2444 	return err;
2445 }
2446 
2447 /*
2448  * By the time this is called, we already have created
2449  * the directory cache entry for the new file, but it
2450  * is so far negative - it has no inode.
2451  *
2452  * If the create succeeds, we fill in the inode information
2453  * with d_instantiate().
2454  */
2455 static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
2456 		       bool excl)
2457 {
2458 	handle_t *handle;
2459 	struct inode *inode;
2460 	int err, credits, retries = 0;
2461 
2462 	err = dquot_initialize(dir);
2463 	if (err)
2464 		return err;
2465 
2466 	credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2467 		   EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2468 retry:
2469 	inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2470 					    NULL, EXT4_HT_DIR, credits);
2471 	handle = ext4_journal_current_handle();
2472 	err = PTR_ERR(inode);
2473 	if (!IS_ERR(inode)) {
2474 		inode->i_op = &ext4_file_inode_operations;
2475 		inode->i_fop = &ext4_file_operations;
2476 		ext4_set_aops(inode);
2477 		err = ext4_add_nondir(handle, dentry, inode);
2478 		if (!err && IS_DIRSYNC(dir))
2479 			ext4_handle_sync(handle);
2480 	}
2481 	if (handle)
2482 		ext4_journal_stop(handle);
2483 	if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2484 		goto retry;
2485 	return err;
2486 }
2487 
2488 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
2489 		      umode_t mode, dev_t rdev)
2490 {
2491 	handle_t *handle;
2492 	struct inode *inode;
2493 	int err, credits, retries = 0;
2494 
2495 	err = dquot_initialize(dir);
2496 	if (err)
2497 		return err;
2498 
2499 	credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2500 		   EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2501 retry:
2502 	inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
2503 					    NULL, EXT4_HT_DIR, credits);
2504 	handle = ext4_journal_current_handle();
2505 	err = PTR_ERR(inode);
2506 	if (!IS_ERR(inode)) {
2507 		init_special_inode(inode, inode->i_mode, rdev);
2508 		inode->i_op = &ext4_special_inode_operations;
2509 		err = ext4_add_nondir(handle, dentry, inode);
2510 		if (!err && IS_DIRSYNC(dir))
2511 			ext4_handle_sync(handle);
2512 	}
2513 	if (handle)
2514 		ext4_journal_stop(handle);
2515 	if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2516 		goto retry;
2517 	return err;
2518 }
2519 
2520 static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
2521 {
2522 	handle_t *handle;
2523 	struct inode *inode;
2524 	int err, retries = 0;
2525 
2526 	err = dquot_initialize(dir);
2527 	if (err)
2528 		return err;
2529 
2530 retry:
2531 	inode = ext4_new_inode_start_handle(dir, mode,
2532 					    NULL, 0, NULL,
2533 					    EXT4_HT_DIR,
2534 			EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2535 			  4 + EXT4_XATTR_TRANS_BLOCKS);
2536 	handle = ext4_journal_current_handle();
2537 	err = PTR_ERR(inode);
2538 	if (!IS_ERR(inode)) {
2539 		inode->i_op = &ext4_file_inode_operations;
2540 		inode->i_fop = &ext4_file_operations;
2541 		ext4_set_aops(inode);
2542 		d_tmpfile(dentry, inode);
2543 		err = ext4_orphan_add(handle, inode);
2544 		if (err)
2545 			goto err_unlock_inode;
2546 		mark_inode_dirty(inode);
2547 		unlock_new_inode(inode);
2548 	}
2549 	if (handle)
2550 		ext4_journal_stop(handle);
2551 	if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2552 		goto retry;
2553 	return err;
2554 err_unlock_inode:
2555 	ext4_journal_stop(handle);
2556 	unlock_new_inode(inode);
2557 	return err;
2558 }
2559 
2560 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2561 			  struct ext4_dir_entry_2 *de,
2562 			  int blocksize, int csum_size,
2563 			  unsigned int parent_ino, int dotdot_real_len)
2564 {
2565 	de->inode = cpu_to_le32(inode->i_ino);
2566 	de->name_len = 1;
2567 	de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
2568 					   blocksize);
2569 	strcpy(de->name, ".");
2570 	ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2571 
2572 	de = ext4_next_entry(de, blocksize);
2573 	de->inode = cpu_to_le32(parent_ino);
2574 	de->name_len = 2;
2575 	if (!dotdot_real_len)
2576 		de->rec_len = ext4_rec_len_to_disk(blocksize -
2577 					(csum_size + EXT4_DIR_REC_LEN(1)),
2578 					blocksize);
2579 	else
2580 		de->rec_len = ext4_rec_len_to_disk(
2581 				EXT4_DIR_REC_LEN(de->name_len), blocksize);
2582 	strcpy(de->name, "..");
2583 	ext4_set_de_type(inode->i_sb, de, S_IFDIR);
2584 
2585 	return ext4_next_entry(de, blocksize);
2586 }
2587 
2588 static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
2589 			     struct inode *inode)
2590 {
2591 	struct buffer_head *dir_block = NULL;
2592 	struct ext4_dir_entry_2 *de;
2593 	struct ext4_dir_entry_tail *t;
2594 	ext4_lblk_t block = 0;
2595 	unsigned int blocksize = dir->i_sb->s_blocksize;
2596 	int csum_size = 0;
2597 	int err;
2598 
2599 	if (ext4_has_metadata_csum(dir->i_sb))
2600 		csum_size = sizeof(struct ext4_dir_entry_tail);
2601 
2602 	if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
2603 		err = ext4_try_create_inline_dir(handle, dir, inode);
2604 		if (err < 0 && err != -ENOSPC)
2605 			goto out;
2606 		if (!err)
2607 			goto out;
2608 	}
2609 
2610 	inode->i_size = 0;
2611 	dir_block = ext4_append(handle, inode, &block);
2612 	if (IS_ERR(dir_block))
2613 		return PTR_ERR(dir_block);
2614 	de = (struct ext4_dir_entry_2 *)dir_block->b_data;
2615 	ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
2616 	set_nlink(inode, 2);
2617 	if (csum_size) {
2618 		t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
2619 		initialize_dirent_tail(t, blocksize);
2620 	}
2621 
2622 	BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2623 	err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
2624 	if (err)
2625 		goto out;
2626 	set_buffer_verified(dir_block);
2627 out:
2628 	brelse(dir_block);
2629 	return err;
2630 }
2631 
2632 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
2633 {
2634 	handle_t *handle;
2635 	struct inode *inode;
2636 	int err, credits, retries = 0;
2637 
2638 	if (EXT4_DIR_LINK_MAX(dir))
2639 		return -EMLINK;
2640 
2641 	err = dquot_initialize(dir);
2642 	if (err)
2643 		return err;
2644 
2645 	credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2646 		   EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2647 retry:
2648 	inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode,
2649 					    &dentry->d_name,
2650 					    0, NULL, EXT4_HT_DIR, credits);
2651 	handle = ext4_journal_current_handle();
2652 	err = PTR_ERR(inode);
2653 	if (IS_ERR(inode))
2654 		goto out_stop;
2655 
2656 	inode->i_op = &ext4_dir_inode_operations;
2657 	inode->i_fop = &ext4_dir_operations;
2658 	err = ext4_init_new_dir(handle, dir, inode);
2659 	if (err)
2660 		goto out_clear_inode;
2661 	err = ext4_mark_inode_dirty(handle, inode);
2662 	if (!err)
2663 		err = ext4_add_entry(handle, dentry, inode);
2664 	if (err) {
2665 out_clear_inode:
2666 		clear_nlink(inode);
2667 		unlock_new_inode(inode);
2668 		ext4_mark_inode_dirty(handle, inode);
2669 		iput(inode);
2670 		goto out_stop;
2671 	}
2672 	ext4_inc_count(handle, dir);
2673 	ext4_update_dx_flag(dir);
2674 	err = ext4_mark_inode_dirty(handle, dir);
2675 	if (err)
2676 		goto out_clear_inode;
2677 	unlock_new_inode(inode);
2678 	d_instantiate(dentry, inode);
2679 	if (IS_DIRSYNC(dir))
2680 		ext4_handle_sync(handle);
2681 
2682 out_stop:
2683 	if (handle)
2684 		ext4_journal_stop(handle);
2685 	if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2686 		goto retry;
2687 	return err;
2688 }
2689 
2690 /*
2691  * routine to check that the specified directory is empty (for rmdir)
2692  */
2693 int ext4_empty_dir(struct inode *inode)
2694 {
2695 	unsigned int offset;
2696 	struct buffer_head *bh;
2697 	struct ext4_dir_entry_2 *de, *de1;
2698 	struct super_block *sb;
2699 	int err = 0;
2700 
2701 	if (ext4_has_inline_data(inode)) {
2702 		int has_inline_data = 1;
2703 
2704 		err = empty_inline_dir(inode, &has_inline_data);
2705 		if (has_inline_data)
2706 			return err;
2707 	}
2708 
2709 	sb = inode->i_sb;
2710 	if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) {
2711 		EXT4_ERROR_INODE(inode, "invalid size");
2712 		return 1;
2713 	}
2714 	bh = ext4_read_dirblock(inode, 0, EITHER);
2715 	if (IS_ERR(bh))
2716 		return 1;
2717 
2718 	de = (struct ext4_dir_entry_2 *) bh->b_data;
2719 	de1 = ext4_next_entry(de, sb->s_blocksize);
2720 	if (le32_to_cpu(de->inode) != inode->i_ino ||
2721 			le32_to_cpu(de1->inode) == 0 ||
2722 			strcmp(".", de->name) || strcmp("..", de1->name)) {
2723 		ext4_warning_inode(inode, "directory missing '.' and/or '..'");
2724 		brelse(bh);
2725 		return 1;
2726 	}
2727 	offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
2728 		 ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
2729 	de = ext4_next_entry(de1, sb->s_blocksize);
2730 	while (offset < inode->i_size) {
2731 		if ((void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
2732 			unsigned int lblock;
2733 			err = 0;
2734 			brelse(bh);
2735 			lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
2736 			bh = ext4_read_dirblock(inode, lblock, EITHER);
2737 			if (IS_ERR(bh))
2738 				return 1;
2739 			de = (struct ext4_dir_entry_2 *) bh->b_data;
2740 		}
2741 		if (ext4_check_dir_entry(inode, NULL, de, bh,
2742 					 bh->b_data, bh->b_size, offset)) {
2743 			de = (struct ext4_dir_entry_2 *)(bh->b_data +
2744 							 sb->s_blocksize);
2745 			offset = (offset | (sb->s_blocksize - 1)) + 1;
2746 			continue;
2747 		}
2748 		if (le32_to_cpu(de->inode)) {
2749 			brelse(bh);
2750 			return 0;
2751 		}
2752 		offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
2753 		de = ext4_next_entry(de, sb->s_blocksize);
2754 	}
2755 	brelse(bh);
2756 	return 1;
2757 }
2758 
2759 /*
2760  * ext4_orphan_add() links an unlinked or truncated inode into a list of
2761  * such inodes, starting at the superblock, in case we crash before the
2762  * file is closed/deleted, or in case the inode truncate spans multiple
2763  * transactions and the last transaction is not recovered after a crash.
2764  *
2765  * At filesystem recovery time, we walk this list deleting unlinked
2766  * inodes and truncating linked inodes in ext4_orphan_cleanup().
2767  *
2768  * Orphan list manipulation functions must be called under i_mutex unless
2769  * we are just creating the inode or deleting it.
2770  */
2771 int ext4_orphan_add(handle_t *handle, struct inode *inode)
2772 {
2773 	struct super_block *sb = inode->i_sb;
2774 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2775 	struct ext4_iloc iloc;
2776 	int err = 0, rc;
2777 	bool dirty = false;
2778 
2779 	if (!sbi->s_journal || is_bad_inode(inode))
2780 		return 0;
2781 
2782 	WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2783 		     !inode_is_locked(inode));
2784 	/*
2785 	 * Exit early if inode already is on orphan list. This is a big speedup
2786 	 * since we don't have to contend on the global s_orphan_lock.
2787 	 */
2788 	if (!list_empty(&EXT4_I(inode)->i_orphan))
2789 		return 0;
2790 
2791 	/*
2792 	 * Orphan handling is only valid for files with data blocks
2793 	 * being truncated, or files being unlinked. Note that we either
2794 	 * hold i_mutex, or the inode can not be referenced from outside,
2795 	 * so i_nlink should not be bumped due to race
2796 	 */
2797 	J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2798 		  S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2799 
2800 	BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2801 	err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2802 	if (err)
2803 		goto out;
2804 
2805 	err = ext4_reserve_inode_write(handle, inode, &iloc);
2806 	if (err)
2807 		goto out;
2808 
2809 	mutex_lock(&sbi->s_orphan_lock);
2810 	/*
2811 	 * Due to previous errors inode may be already a part of on-disk
2812 	 * orphan list. If so skip on-disk list modification.
2813 	 */
2814 	if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) >
2815 	    (le32_to_cpu(sbi->s_es->s_inodes_count))) {
2816 		/* Insert this inode at the head of the on-disk orphan list */
2817 		NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan);
2818 		sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2819 		dirty = true;
2820 	}
2821 	list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan);
2822 	mutex_unlock(&sbi->s_orphan_lock);
2823 
2824 	if (dirty) {
2825 		err = ext4_handle_dirty_super(handle, sb);
2826 		rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2827 		if (!err)
2828 			err = rc;
2829 		if (err) {
2830 			/*
2831 			 * We have to remove inode from in-memory list if
2832 			 * addition to on disk orphan list failed. Stray orphan
2833 			 * list entries can cause panics at unmount time.
2834 			 */
2835 			mutex_lock(&sbi->s_orphan_lock);
2836 			list_del_init(&EXT4_I(inode)->i_orphan);
2837 			mutex_unlock(&sbi->s_orphan_lock);
2838 		}
2839 	}
2840 	jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2841 	jbd_debug(4, "orphan inode %lu will point to %d\n",
2842 			inode->i_ino, NEXT_ORPHAN(inode));
2843 out:
2844 	ext4_std_error(sb, err);
2845 	return err;
2846 }
2847 
2848 /*
2849  * ext4_orphan_del() removes an unlinked or truncated inode from the list
2850  * of such inodes stored on disk, because it is finally being cleaned up.
2851  */
2852 int ext4_orphan_del(handle_t *handle, struct inode *inode)
2853 {
2854 	struct list_head *prev;
2855 	struct ext4_inode_info *ei = EXT4_I(inode);
2856 	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2857 	__u32 ino_next;
2858 	struct ext4_iloc iloc;
2859 	int err = 0;
2860 
2861 	if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS))
2862 		return 0;
2863 
2864 	WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
2865 		     !inode_is_locked(inode));
2866 	/* Do this quick check before taking global s_orphan_lock. */
2867 	if (list_empty(&ei->i_orphan))
2868 		return 0;
2869 
2870 	if (handle) {
2871 		/* Grab inode buffer early before taking global s_orphan_lock */
2872 		err = ext4_reserve_inode_write(handle, inode, &iloc);
2873 	}
2874 
2875 	mutex_lock(&sbi->s_orphan_lock);
2876 	jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2877 
2878 	prev = ei->i_orphan.prev;
2879 	list_del_init(&ei->i_orphan);
2880 
2881 	/* If we're on an error path, we may not have a valid
2882 	 * transaction handle with which to update the orphan list on
2883 	 * disk, but we still need to remove the inode from the linked
2884 	 * list in memory. */
2885 	if (!handle || err) {
2886 		mutex_unlock(&sbi->s_orphan_lock);
2887 		goto out_err;
2888 	}
2889 
2890 	ino_next = NEXT_ORPHAN(inode);
2891 	if (prev == &sbi->s_orphan) {
2892 		jbd_debug(4, "superblock will point to %u\n", ino_next);
2893 		BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2894 		err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2895 		if (err) {
2896 			mutex_unlock(&sbi->s_orphan_lock);
2897 			goto out_brelse;
2898 		}
2899 		sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2900 		mutex_unlock(&sbi->s_orphan_lock);
2901 		err = ext4_handle_dirty_super(handle, inode->i_sb);
2902 	} else {
2903 		struct ext4_iloc iloc2;
2904 		struct inode *i_prev =
2905 			&list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2906 
2907 		jbd_debug(4, "orphan inode %lu will point to %u\n",
2908 			  i_prev->i_ino, ino_next);
2909 		err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2910 		if (err) {
2911 			mutex_unlock(&sbi->s_orphan_lock);
2912 			goto out_brelse;
2913 		}
2914 		NEXT_ORPHAN(i_prev) = ino_next;
2915 		err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2916 		mutex_unlock(&sbi->s_orphan_lock);
2917 	}
2918 	if (err)
2919 		goto out_brelse;
2920 	NEXT_ORPHAN(inode) = 0;
2921 	err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2922 out_err:
2923 	ext4_std_error(inode->i_sb, err);
2924 	return err;
2925 
2926 out_brelse:
2927 	brelse(iloc.bh);
2928 	goto out_err;
2929 }
2930 
2931 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2932 {
2933 	int retval;
2934 	struct inode *inode;
2935 	struct buffer_head *bh;
2936 	struct ext4_dir_entry_2 *de;
2937 	handle_t *handle = NULL;
2938 
2939 	/* Initialize quotas before so that eventual writes go in
2940 	 * separate transaction */
2941 	retval = dquot_initialize(dir);
2942 	if (retval)
2943 		return retval;
2944 	retval = dquot_initialize(d_inode(dentry));
2945 	if (retval)
2946 		return retval;
2947 
2948 	retval = -ENOENT;
2949 	bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
2950 	if (IS_ERR(bh))
2951 		return PTR_ERR(bh);
2952 	if (!bh)
2953 		goto end_rmdir;
2954 
2955 	inode = d_inode(dentry);
2956 
2957 	retval = -EFSCORRUPTED;
2958 	if (le32_to_cpu(de->inode) != inode->i_ino)
2959 		goto end_rmdir;
2960 
2961 	retval = -ENOTEMPTY;
2962 	if (!ext4_empty_dir(inode))
2963 		goto end_rmdir;
2964 
2965 	handle = ext4_journal_start(dir, EXT4_HT_DIR,
2966 				    EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
2967 	if (IS_ERR(handle)) {
2968 		retval = PTR_ERR(handle);
2969 		handle = NULL;
2970 		goto end_rmdir;
2971 	}
2972 
2973 	if (IS_DIRSYNC(dir))
2974 		ext4_handle_sync(handle);
2975 
2976 	retval = ext4_delete_entry(handle, dir, de, bh);
2977 	if (retval)
2978 		goto end_rmdir;
2979 	if (!EXT4_DIR_LINK_EMPTY(inode))
2980 		ext4_warning_inode(inode,
2981 			     "empty directory '%.*s' has too many links (%u)",
2982 			     dentry->d_name.len, dentry->d_name.name,
2983 			     inode->i_nlink);
2984 	inode->i_version++;
2985 	clear_nlink(inode);
2986 	/* There's no need to set i_disksize: the fact that i_nlink is
2987 	 * zero will ensure that the right thing happens during any
2988 	 * recovery. */
2989 	inode->i_size = 0;
2990 	ext4_orphan_add(handle, inode);
2991 	inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
2992 	ext4_mark_inode_dirty(handle, inode);
2993 	ext4_dec_count(handle, dir);
2994 	ext4_update_dx_flag(dir);
2995 	ext4_mark_inode_dirty(handle, dir);
2996 
2997 end_rmdir:
2998 	brelse(bh);
2999 	if (handle)
3000 		ext4_journal_stop(handle);
3001 	return retval;
3002 }
3003 
3004 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
3005 {
3006 	int retval;
3007 	struct inode *inode;
3008 	struct buffer_head *bh;
3009 	struct ext4_dir_entry_2 *de;
3010 	handle_t *handle = NULL;
3011 
3012 	trace_ext4_unlink_enter(dir, dentry);
3013 	/* Initialize quotas before so that eventual writes go
3014 	 * in separate transaction */
3015 	retval = dquot_initialize(dir);
3016 	if (retval)
3017 		return retval;
3018 	retval = dquot_initialize(d_inode(dentry));
3019 	if (retval)
3020 		return retval;
3021 
3022 	retval = -ENOENT;
3023 	bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
3024 	if (IS_ERR(bh))
3025 		return PTR_ERR(bh);
3026 	if (!bh)
3027 		goto end_unlink;
3028 
3029 	inode = d_inode(dentry);
3030 
3031 	retval = -EFSCORRUPTED;
3032 	if (le32_to_cpu(de->inode) != inode->i_ino)
3033 		goto end_unlink;
3034 
3035 	handle = ext4_journal_start(dir, EXT4_HT_DIR,
3036 				    EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3037 	if (IS_ERR(handle)) {
3038 		retval = PTR_ERR(handle);
3039 		handle = NULL;
3040 		goto end_unlink;
3041 	}
3042 
3043 	if (IS_DIRSYNC(dir))
3044 		ext4_handle_sync(handle);
3045 
3046 	if (inode->i_nlink == 0) {
3047 		ext4_warning_inode(inode, "Deleting file '%.*s' with no links",
3048 				   dentry->d_name.len, dentry->d_name.name);
3049 		set_nlink(inode, 1);
3050 	}
3051 	retval = ext4_delete_entry(handle, dir, de, bh);
3052 	if (retval)
3053 		goto end_unlink;
3054 	dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
3055 	ext4_update_dx_flag(dir);
3056 	ext4_mark_inode_dirty(handle, dir);
3057 	drop_nlink(inode);
3058 	if (!inode->i_nlink)
3059 		ext4_orphan_add(handle, inode);
3060 	inode->i_ctime = ext4_current_time(inode);
3061 	ext4_mark_inode_dirty(handle, inode);
3062 
3063 end_unlink:
3064 	brelse(bh);
3065 	if (handle)
3066 		ext4_journal_stop(handle);
3067 	trace_ext4_unlink_exit(dentry, retval);
3068 	return retval;
3069 }
3070 
3071 static int ext4_symlink(struct inode *dir,
3072 			struct dentry *dentry, const char *symname)
3073 {
3074 	handle_t *handle;
3075 	struct inode *inode;
3076 	int err, len = strlen(symname);
3077 	int credits;
3078 	bool encryption_required;
3079 	struct ext4_str disk_link;
3080 	struct ext4_encrypted_symlink_data *sd = NULL;
3081 
3082 	disk_link.len = len + 1;
3083 	disk_link.name = (char *) symname;
3084 
3085 	encryption_required = (ext4_encrypted_inode(dir) ||
3086 			       DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb)));
3087 	if (encryption_required) {
3088 		err = ext4_get_encryption_info(dir);
3089 		if (err)
3090 			return err;
3091 		if (ext4_encryption_info(dir) == NULL)
3092 			return -EPERM;
3093 		disk_link.len = (ext4_fname_encrypted_size(dir, len) +
3094 				 sizeof(struct ext4_encrypted_symlink_data));
3095 		sd = kzalloc(disk_link.len, GFP_KERNEL);
3096 		if (!sd)
3097 			return -ENOMEM;
3098 	}
3099 
3100 	if (disk_link.len > dir->i_sb->s_blocksize) {
3101 		err = -ENAMETOOLONG;
3102 		goto err_free_sd;
3103 	}
3104 
3105 	err = dquot_initialize(dir);
3106 	if (err)
3107 		goto err_free_sd;
3108 
3109 	if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3110 		/*
3111 		 * For non-fast symlinks, we just allocate inode and put it on
3112 		 * orphan list in the first transaction => we need bitmap,
3113 		 * group descriptor, sb, inode block, quota blocks, and
3114 		 * possibly selinux xattr blocks.
3115 		 */
3116 		credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
3117 			  EXT4_XATTR_TRANS_BLOCKS;
3118 	} else {
3119 		/*
3120 		 * Fast symlink. We have to add entry to directory
3121 		 * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS),
3122 		 * allocate new inode (bitmap, group descriptor, inode block,
3123 		 * quota blocks, sb is already counted in previous macros).
3124 		 */
3125 		credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3126 			  EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
3127 	}
3128 
3129 	inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO,
3130 					    &dentry->d_name, 0, NULL,
3131 					    EXT4_HT_DIR, credits);
3132 	handle = ext4_journal_current_handle();
3133 	if (IS_ERR(inode)) {
3134 		if (handle)
3135 			ext4_journal_stop(handle);
3136 		err = PTR_ERR(inode);
3137 		goto err_free_sd;
3138 	}
3139 
3140 	if (encryption_required) {
3141 		struct qstr istr;
3142 		struct ext4_str ostr;
3143 
3144 		istr.name = (const unsigned char *) symname;
3145 		istr.len = len;
3146 		ostr.name = sd->encrypted_path;
3147 		ostr.len = disk_link.len;
3148 		err = ext4_fname_usr_to_disk(inode, &istr, &ostr);
3149 		if (err < 0)
3150 			goto err_drop_inode;
3151 		sd->len = cpu_to_le16(ostr.len);
3152 		disk_link.name = (char *) sd;
3153 		inode->i_op = &ext4_encrypted_symlink_inode_operations;
3154 	}
3155 
3156 	if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3157 		if (!encryption_required)
3158 			inode->i_op = &ext4_symlink_inode_operations;
3159 		inode_nohighmem(inode);
3160 		ext4_set_aops(inode);
3161 		/*
3162 		 * We cannot call page_symlink() with transaction started
3163 		 * because it calls into ext4_write_begin() which can wait
3164 		 * for transaction commit if we are running out of space
3165 		 * and thus we deadlock. So we have to stop transaction now
3166 		 * and restart it when symlink contents is written.
3167 		 *
3168 		 * To keep fs consistent in case of crash, we have to put inode
3169 		 * to orphan list in the mean time.
3170 		 */
3171 		drop_nlink(inode);
3172 		err = ext4_orphan_add(handle, inode);
3173 		ext4_journal_stop(handle);
3174 		handle = NULL;
3175 		if (err)
3176 			goto err_drop_inode;
3177 		err = __page_symlink(inode, disk_link.name, disk_link.len, 1);
3178 		if (err)
3179 			goto err_drop_inode;
3180 		/*
3181 		 * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS
3182 		 * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified
3183 		 */
3184 		handle = ext4_journal_start(dir, EXT4_HT_DIR,
3185 				EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3186 				EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1);
3187 		if (IS_ERR(handle)) {
3188 			err = PTR_ERR(handle);
3189 			handle = NULL;
3190 			goto err_drop_inode;
3191 		}
3192 		set_nlink(inode, 1);
3193 		err = ext4_orphan_del(handle, inode);
3194 		if (err)
3195 			goto err_drop_inode;
3196 	} else {
3197 		/* clear the extent format for fast symlink */
3198 		ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
3199 		if (!encryption_required) {
3200 			inode->i_op = &ext4_fast_symlink_inode_operations;
3201 			inode->i_link = (char *)&EXT4_I(inode)->i_data;
3202 		}
3203 		memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name,
3204 		       disk_link.len);
3205 		inode->i_size = disk_link.len - 1;
3206 	}
3207 	EXT4_I(inode)->i_disksize = inode->i_size;
3208 	err = ext4_add_nondir(handle, dentry, inode);
3209 	if (!err && IS_DIRSYNC(dir))
3210 		ext4_handle_sync(handle);
3211 
3212 	if (handle)
3213 		ext4_journal_stop(handle);
3214 	kfree(sd);
3215 	return err;
3216 err_drop_inode:
3217 	if (handle)
3218 		ext4_journal_stop(handle);
3219 	clear_nlink(inode);
3220 	unlock_new_inode(inode);
3221 	iput(inode);
3222 err_free_sd:
3223 	kfree(sd);
3224 	return err;
3225 }
3226 
3227 static int ext4_link(struct dentry *old_dentry,
3228 		     struct inode *dir, struct dentry *dentry)
3229 {
3230 	handle_t *handle;
3231 	struct inode *inode = d_inode(old_dentry);
3232 	int err, retries = 0;
3233 
3234 	if (inode->i_nlink >= EXT4_LINK_MAX)
3235 		return -EMLINK;
3236 	if (ext4_encrypted_inode(dir) &&
3237 	    !ext4_is_child_context_consistent_with_parent(dir, inode))
3238 		return -EPERM;
3239 
3240        if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) &&
3241 	   (!projid_eq(EXT4_I(dir)->i_projid,
3242 		       EXT4_I(old_dentry->d_inode)->i_projid)))
3243 		return -EXDEV;
3244 
3245 	err = dquot_initialize(dir);
3246 	if (err)
3247 		return err;
3248 
3249 retry:
3250 	handle = ext4_journal_start(dir, EXT4_HT_DIR,
3251 		(EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3252 		 EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1);
3253 	if (IS_ERR(handle))
3254 		return PTR_ERR(handle);
3255 
3256 	if (IS_DIRSYNC(dir))
3257 		ext4_handle_sync(handle);
3258 
3259 	inode->i_ctime = ext4_current_time(inode);
3260 	ext4_inc_count(handle, inode);
3261 	ihold(inode);
3262 
3263 	err = ext4_add_entry(handle, dentry, inode);
3264 	if (!err) {
3265 		ext4_mark_inode_dirty(handle, inode);
3266 		/* this can happen only for tmpfile being
3267 		 * linked the first time
3268 		 */
3269 		if (inode->i_nlink == 1)
3270 			ext4_orphan_del(handle, inode);
3271 		d_instantiate(dentry, inode);
3272 	} else {
3273 		drop_nlink(inode);
3274 		iput(inode);
3275 	}
3276 	ext4_journal_stop(handle);
3277 	if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
3278 		goto retry;
3279 	return err;
3280 }
3281 
3282 
3283 /*
3284  * Try to find buffer head where contains the parent block.
3285  * It should be the inode block if it is inlined or the 1st block
3286  * if it is a normal dir.
3287  */
3288 static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
3289 					struct inode *inode,
3290 					int *retval,
3291 					struct ext4_dir_entry_2 **parent_de,
3292 					int *inlined)
3293 {
3294 	struct buffer_head *bh;
3295 
3296 	if (!ext4_has_inline_data(inode)) {
3297 		bh = ext4_read_dirblock(inode, 0, EITHER);
3298 		if (IS_ERR(bh)) {
3299 			*retval = PTR_ERR(bh);
3300 			return NULL;
3301 		}
3302 		*parent_de = ext4_next_entry(
3303 					(struct ext4_dir_entry_2 *)bh->b_data,
3304 					inode->i_sb->s_blocksize);
3305 		return bh;
3306 	}
3307 
3308 	*inlined = 1;
3309 	return ext4_get_first_inline_block(inode, parent_de, retval);
3310 }
3311 
3312 struct ext4_renament {
3313 	struct inode *dir;
3314 	struct dentry *dentry;
3315 	struct inode *inode;
3316 	bool is_dir;
3317 	int dir_nlink_delta;
3318 
3319 	/* entry for "dentry" */
3320 	struct buffer_head *bh;
3321 	struct ext4_dir_entry_2 *de;
3322 	int inlined;
3323 
3324 	/* entry for ".." in inode if it's a directory */
3325 	struct buffer_head *dir_bh;
3326 	struct ext4_dir_entry_2 *parent_de;
3327 	int dir_inlined;
3328 };
3329 
3330 static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent)
3331 {
3332 	int retval;
3333 
3334 	ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode,
3335 					      &retval, &ent->parent_de,
3336 					      &ent->dir_inlined);
3337 	if (!ent->dir_bh)
3338 		return retval;
3339 	if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
3340 		return -EFSCORRUPTED;
3341 	BUFFER_TRACE(ent->dir_bh, "get_write_access");
3342 	return ext4_journal_get_write_access(handle, ent->dir_bh);
3343 }
3344 
3345 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent,
3346 				  unsigned dir_ino)
3347 {
3348 	int retval;
3349 
3350 	ent->parent_de->inode = cpu_to_le32(dir_ino);
3351 	BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata");
3352 	if (!ent->dir_inlined) {
3353 		if (is_dx(ent->inode)) {
3354 			retval = ext4_handle_dirty_dx_node(handle,
3355 							   ent->inode,
3356 							   ent->dir_bh);
3357 		} else {
3358 			retval = ext4_handle_dirty_dirent_node(handle,
3359 							       ent->inode,
3360 							       ent->dir_bh);
3361 		}
3362 	} else {
3363 		retval = ext4_mark_inode_dirty(handle, ent->inode);
3364 	}
3365 	if (retval) {
3366 		ext4_std_error(ent->dir->i_sb, retval);
3367 		return retval;
3368 	}
3369 	return 0;
3370 }
3371 
3372 static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
3373 		       unsigned ino, unsigned file_type)
3374 {
3375 	int retval;
3376 
3377 	BUFFER_TRACE(ent->bh, "get write access");
3378 	retval = ext4_journal_get_write_access(handle, ent->bh);
3379 	if (retval)
3380 		return retval;
3381 	ent->de->inode = cpu_to_le32(ino);
3382 	if (ext4_has_feature_filetype(ent->dir->i_sb))
3383 		ent->de->file_type = file_type;
3384 	ent->dir->i_version++;
3385 	ent->dir->i_ctime = ent->dir->i_mtime =
3386 		ext4_current_time(ent->dir);
3387 	ext4_mark_inode_dirty(handle, ent->dir);
3388 	BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata");
3389 	if (!ent->inlined) {
3390 		retval = ext4_handle_dirty_dirent_node(handle,
3391 						       ent->dir, ent->bh);
3392 		if (unlikely(retval)) {
3393 			ext4_std_error(ent->dir->i_sb, retval);
3394 			return retval;
3395 		}
3396 	}
3397 	brelse(ent->bh);
3398 	ent->bh = NULL;
3399 
3400 	return 0;
3401 }
3402 
3403 static int ext4_find_delete_entry(handle_t *handle, struct inode *dir,
3404 				  const struct qstr *d_name)
3405 {
3406 	int retval = -ENOENT;
3407 	struct buffer_head *bh;
3408 	struct ext4_dir_entry_2 *de;
3409 
3410 	bh = ext4_find_entry(dir, d_name, &de, NULL);
3411 	if (IS_ERR(bh))
3412 		return PTR_ERR(bh);
3413 	if (bh) {
3414 		retval = ext4_delete_entry(handle, dir, de, bh);
3415 		brelse(bh);
3416 	}
3417 	return retval;
3418 }
3419 
3420 static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent,
3421 			       int force_reread)
3422 {
3423 	int retval;
3424 	/*
3425 	 * ent->de could have moved from under us during htree split, so make
3426 	 * sure that we are deleting the right entry.  We might also be pointing
3427 	 * to a stale entry in the unused part of ent->bh so just checking inum
3428 	 * and the name isn't enough.
3429 	 */
3430 	if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino ||
3431 	    ent->de->name_len != ent->dentry->d_name.len ||
3432 	    strncmp(ent->de->name, ent->dentry->d_name.name,
3433 		    ent->de->name_len) ||
3434 	    force_reread) {
3435 		retval = ext4_find_delete_entry(handle, ent->dir,
3436 						&ent->dentry->d_name);
3437 	} else {
3438 		retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh);
3439 		if (retval == -ENOENT) {
3440 			retval = ext4_find_delete_entry(handle, ent->dir,
3441 							&ent->dentry->d_name);
3442 		}
3443 	}
3444 
3445 	if (retval) {
3446 		ext4_warning_inode(ent->dir,
3447 				   "Deleting old file: nlink %d, error=%d",
3448 				   ent->dir->i_nlink, retval);
3449 	}
3450 }
3451 
3452 static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent)
3453 {
3454 	if (ent->dir_nlink_delta) {
3455 		if (ent->dir_nlink_delta == -1)
3456 			ext4_dec_count(handle, ent->dir);
3457 		else
3458 			ext4_inc_count(handle, ent->dir);
3459 		ext4_mark_inode_dirty(handle, ent->dir);
3460 	}
3461 }
3462 
3463 static struct inode *ext4_whiteout_for_rename(struct ext4_renament *ent,
3464 					      int credits, handle_t **h)
3465 {
3466 	struct inode *wh;
3467 	handle_t *handle;
3468 	int retries = 0;
3469 
3470 	/*
3471 	 * for inode block, sb block, group summaries,
3472 	 * and inode bitmap
3473 	 */
3474 	credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) +
3475 		    EXT4_XATTR_TRANS_BLOCKS + 4);
3476 retry:
3477 	wh = ext4_new_inode_start_handle(ent->dir, S_IFCHR | WHITEOUT_MODE,
3478 					 &ent->dentry->d_name, 0, NULL,
3479 					 EXT4_HT_DIR, credits);
3480 
3481 	handle = ext4_journal_current_handle();
3482 	if (IS_ERR(wh)) {
3483 		if (handle)
3484 			ext4_journal_stop(handle);
3485 		if (PTR_ERR(wh) == -ENOSPC &&
3486 		    ext4_should_retry_alloc(ent->dir->i_sb, &retries))
3487 			goto retry;
3488 	} else {
3489 		*h = handle;
3490 		init_special_inode(wh, wh->i_mode, WHITEOUT_DEV);
3491 		wh->i_op = &ext4_special_inode_operations;
3492 	}
3493 	return wh;
3494 }
3495 
3496 /*
3497  * Anybody can rename anything with this: the permission checks are left to the
3498  * higher-level routines.
3499  *
3500  * n.b.  old_{dentry,inode) refers to the source dentry/inode
3501  * while new_{dentry,inode) refers to the destination dentry/inode
3502  * This comes from rename(const char *oldpath, const char *newpath)
3503  */
3504 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
3505 		       struct inode *new_dir, struct dentry *new_dentry,
3506 		       unsigned int flags)
3507 {
3508 	handle_t *handle = NULL;
3509 	struct ext4_renament old = {
3510 		.dir = old_dir,
3511 		.dentry = old_dentry,
3512 		.inode = d_inode(old_dentry),
3513 	};
3514 	struct ext4_renament new = {
3515 		.dir = new_dir,
3516 		.dentry = new_dentry,
3517 		.inode = d_inode(new_dentry),
3518 	};
3519 	int force_reread;
3520 	int retval;
3521 	struct inode *whiteout = NULL;
3522 	int credits;
3523 	u8 old_file_type;
3524 
3525 	if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT)) &&
3526 	    (!projid_eq(EXT4_I(new_dir)->i_projid,
3527 			EXT4_I(old_dentry->d_inode)->i_projid)))
3528 		return -EXDEV;
3529 
3530 	retval = dquot_initialize(old.dir);
3531 	if (retval)
3532 		return retval;
3533 	retval = dquot_initialize(new.dir);
3534 	if (retval)
3535 		return retval;
3536 
3537 	/* Initialize quotas before so that eventual writes go
3538 	 * in separate transaction */
3539 	if (new.inode) {
3540 		retval = dquot_initialize(new.inode);
3541 		if (retval)
3542 			return retval;
3543 	}
3544 
3545 	old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
3546 	if (IS_ERR(old.bh))
3547 		return PTR_ERR(old.bh);
3548 	/*
3549 	 *  Check for inode number is _not_ due to possible IO errors.
3550 	 *  We might rmdir the source, keep it as pwd of some process
3551 	 *  and merrily kill the link to whatever was created under the
3552 	 *  same name. Goodbye sticky bit ;-<
3553 	 */
3554 	retval = -ENOENT;
3555 	if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3556 		goto end_rename;
3557 
3558 	if ((old.dir != new.dir) &&
3559 	    ext4_encrypted_inode(new.dir) &&
3560 	    !ext4_is_child_context_consistent_with_parent(new.dir,
3561 							  old.inode)) {
3562 		retval = -EPERM;
3563 		goto end_rename;
3564 	}
3565 
3566 	new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3567 				 &new.de, &new.inlined);
3568 	if (IS_ERR(new.bh)) {
3569 		retval = PTR_ERR(new.bh);
3570 		new.bh = NULL;
3571 		goto end_rename;
3572 	}
3573 	if (new.bh) {
3574 		if (!new.inode) {
3575 			brelse(new.bh);
3576 			new.bh = NULL;
3577 		}
3578 	}
3579 	if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC))
3580 		ext4_alloc_da_blocks(old.inode);
3581 
3582 	credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3583 		   EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
3584 	if (!(flags & RENAME_WHITEOUT)) {
3585 		handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits);
3586 		if (IS_ERR(handle)) {
3587 			retval = PTR_ERR(handle);
3588 			handle = NULL;
3589 			goto end_rename;
3590 		}
3591 	} else {
3592 		whiteout = ext4_whiteout_for_rename(&old, credits, &handle);
3593 		if (IS_ERR(whiteout)) {
3594 			retval = PTR_ERR(whiteout);
3595 			whiteout = NULL;
3596 			goto end_rename;
3597 		}
3598 	}
3599 
3600 	if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3601 		ext4_handle_sync(handle);
3602 
3603 	if (S_ISDIR(old.inode->i_mode)) {
3604 		if (new.inode) {
3605 			retval = -ENOTEMPTY;
3606 			if (!ext4_empty_dir(new.inode))
3607 				goto end_rename;
3608 		} else {
3609 			retval = -EMLINK;
3610 			if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir))
3611 				goto end_rename;
3612 		}
3613 		retval = ext4_rename_dir_prepare(handle, &old);
3614 		if (retval)
3615 			goto end_rename;
3616 	}
3617 	/*
3618 	 * If we're renaming a file within an inline_data dir and adding or
3619 	 * setting the new dirent causes a conversion from inline_data to
3620 	 * extents/blockmap, we need to force the dirent delete code to
3621 	 * re-read the directory, or else we end up trying to delete a dirent
3622 	 * from what is now the extent tree root (or a block map).
3623 	 */
3624 	force_reread = (new.dir->i_ino == old.dir->i_ino &&
3625 			ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA));
3626 
3627 	old_file_type = old.de->file_type;
3628 	if (whiteout) {
3629 		/*
3630 		 * Do this before adding a new entry, so the old entry is sure
3631 		 * to be still pointing to the valid old entry.
3632 		 */
3633 		retval = ext4_setent(handle, &old, whiteout->i_ino,
3634 				     EXT4_FT_CHRDEV);
3635 		if (retval)
3636 			goto end_rename;
3637 		ext4_mark_inode_dirty(handle, whiteout);
3638 	}
3639 	if (!new.bh) {
3640 		retval = ext4_add_entry(handle, new.dentry, old.inode);
3641 		if (retval)
3642 			goto end_rename;
3643 	} else {
3644 		retval = ext4_setent(handle, &new,
3645 				     old.inode->i_ino, old_file_type);
3646 		if (retval)
3647 			goto end_rename;
3648 	}
3649 	if (force_reread)
3650 		force_reread = !ext4_test_inode_flag(new.dir,
3651 						     EXT4_INODE_INLINE_DATA);
3652 
3653 	/*
3654 	 * Like most other Unix systems, set the ctime for inodes on a
3655 	 * rename.
3656 	 */
3657 	old.inode->i_ctime = ext4_current_time(old.inode);
3658 	ext4_mark_inode_dirty(handle, old.inode);
3659 
3660 	if (!whiteout) {
3661 		/*
3662 		 * ok, that's it
3663 		 */
3664 		ext4_rename_delete(handle, &old, force_reread);
3665 	}
3666 
3667 	if (new.inode) {
3668 		ext4_dec_count(handle, new.inode);
3669 		new.inode->i_ctime = ext4_current_time(new.inode);
3670 	}
3671 	old.dir->i_ctime = old.dir->i_mtime = ext4_current_time(old.dir);
3672 	ext4_update_dx_flag(old.dir);
3673 	if (old.dir_bh) {
3674 		retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3675 		if (retval)
3676 			goto end_rename;
3677 
3678 		ext4_dec_count(handle, old.dir);
3679 		if (new.inode) {
3680 			/* checked ext4_empty_dir above, can't have another
3681 			 * parent, ext4_dec_count() won't work for many-linked
3682 			 * dirs */
3683 			clear_nlink(new.inode);
3684 		} else {
3685 			ext4_inc_count(handle, new.dir);
3686 			ext4_update_dx_flag(new.dir);
3687 			ext4_mark_inode_dirty(handle, new.dir);
3688 		}
3689 	}
3690 	ext4_mark_inode_dirty(handle, old.dir);
3691 	if (new.inode) {
3692 		ext4_mark_inode_dirty(handle, new.inode);
3693 		if (!new.inode->i_nlink)
3694 			ext4_orphan_add(handle, new.inode);
3695 	}
3696 	retval = 0;
3697 
3698 end_rename:
3699 	brelse(old.dir_bh);
3700 	brelse(old.bh);
3701 	brelse(new.bh);
3702 	if (whiteout) {
3703 		if (retval)
3704 			drop_nlink(whiteout);
3705 		unlock_new_inode(whiteout);
3706 		iput(whiteout);
3707 	}
3708 	if (handle)
3709 		ext4_journal_stop(handle);
3710 	return retval;
3711 }
3712 
3713 static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
3714 			     struct inode *new_dir, struct dentry *new_dentry)
3715 {
3716 	handle_t *handle = NULL;
3717 	struct ext4_renament old = {
3718 		.dir = old_dir,
3719 		.dentry = old_dentry,
3720 		.inode = d_inode(old_dentry),
3721 	};
3722 	struct ext4_renament new = {
3723 		.dir = new_dir,
3724 		.dentry = new_dentry,
3725 		.inode = d_inode(new_dentry),
3726 	};
3727 	u8 new_file_type;
3728 	int retval;
3729 
3730 	if ((ext4_encrypted_inode(old_dir) ||
3731 	     ext4_encrypted_inode(new_dir)) &&
3732 	    (old_dir != new_dir) &&
3733 	    (!ext4_is_child_context_consistent_with_parent(new_dir,
3734 							   old.inode) ||
3735 	     !ext4_is_child_context_consistent_with_parent(old_dir,
3736 							   new.inode)))
3737 		return -EPERM;
3738 
3739 	if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) &&
3740 	     !projid_eq(EXT4_I(new_dir)->i_projid,
3741 			EXT4_I(old_dentry->d_inode)->i_projid)) ||
3742 	    (ext4_test_inode_flag(old_dir, EXT4_INODE_PROJINHERIT) &&
3743 	     !projid_eq(EXT4_I(old_dir)->i_projid,
3744 			EXT4_I(new_dentry->d_inode)->i_projid)))
3745 		return -EXDEV;
3746 
3747 	retval = dquot_initialize(old.dir);
3748 	if (retval)
3749 		return retval;
3750 	retval = dquot_initialize(new.dir);
3751 	if (retval)
3752 		return retval;
3753 
3754 	old.bh = ext4_find_entry(old.dir, &old.dentry->d_name,
3755 				 &old.de, &old.inlined);
3756 	if (IS_ERR(old.bh))
3757 		return PTR_ERR(old.bh);
3758 	/*
3759 	 *  Check for inode number is _not_ due to possible IO errors.
3760 	 *  We might rmdir the source, keep it as pwd of some process
3761 	 *  and merrily kill the link to whatever was created under the
3762 	 *  same name. Goodbye sticky bit ;-<
3763 	 */
3764 	retval = -ENOENT;
3765 	if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3766 		goto end_rename;
3767 
3768 	new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
3769 				 &new.de, &new.inlined);
3770 	if (IS_ERR(new.bh)) {
3771 		retval = PTR_ERR(new.bh);
3772 		new.bh = NULL;
3773 		goto end_rename;
3774 	}
3775 
3776 	/* RENAME_EXCHANGE case: old *and* new must both exist */
3777 	if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino)
3778 		goto end_rename;
3779 
3780 	handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
3781 		(2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3782 		 2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
3783 	if (IS_ERR(handle)) {
3784 		retval = PTR_ERR(handle);
3785 		handle = NULL;
3786 		goto end_rename;
3787 	}
3788 
3789 	if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3790 		ext4_handle_sync(handle);
3791 
3792 	if (S_ISDIR(old.inode->i_mode)) {
3793 		old.is_dir = true;
3794 		retval = ext4_rename_dir_prepare(handle, &old);
3795 		if (retval)
3796 			goto end_rename;
3797 	}
3798 	if (S_ISDIR(new.inode->i_mode)) {
3799 		new.is_dir = true;
3800 		retval = ext4_rename_dir_prepare(handle, &new);
3801 		if (retval)
3802 			goto end_rename;
3803 	}
3804 
3805 	/*
3806 	 * Other than the special case of overwriting a directory, parents'
3807 	 * nlink only needs to be modified if this is a cross directory rename.
3808 	 */
3809 	if (old.dir != new.dir && old.is_dir != new.is_dir) {
3810 		old.dir_nlink_delta = old.is_dir ? -1 : 1;
3811 		new.dir_nlink_delta = -old.dir_nlink_delta;
3812 		retval = -EMLINK;
3813 		if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) ||
3814 		    (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir)))
3815 			goto end_rename;
3816 	}
3817 
3818 	new_file_type = new.de->file_type;
3819 	retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type);
3820 	if (retval)
3821 		goto end_rename;
3822 
3823 	retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type);
3824 	if (retval)
3825 		goto end_rename;
3826 
3827 	/*
3828 	 * Like most other Unix systems, set the ctime for inodes on a
3829 	 * rename.
3830 	 */
3831 	old.inode->i_ctime = ext4_current_time(old.inode);
3832 	new.inode->i_ctime = ext4_current_time(new.inode);
3833 	ext4_mark_inode_dirty(handle, old.inode);
3834 	ext4_mark_inode_dirty(handle, new.inode);
3835 
3836 	if (old.dir_bh) {
3837 		retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
3838 		if (retval)
3839 			goto end_rename;
3840 	}
3841 	if (new.dir_bh) {
3842 		retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino);
3843 		if (retval)
3844 			goto end_rename;
3845 	}
3846 	ext4_update_dir_count(handle, &old);
3847 	ext4_update_dir_count(handle, &new);
3848 	retval = 0;
3849 
3850 end_rename:
3851 	brelse(old.dir_bh);
3852 	brelse(new.dir_bh);
3853 	brelse(old.bh);
3854 	brelse(new.bh);
3855 	if (handle)
3856 		ext4_journal_stop(handle);
3857 	return retval;
3858 }
3859 
3860 static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry,
3861 			struct inode *new_dir, struct dentry *new_dentry,
3862 			unsigned int flags)
3863 {
3864 	if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
3865 		return -EINVAL;
3866 
3867 	if (flags & RENAME_EXCHANGE) {
3868 		return ext4_cross_rename(old_dir, old_dentry,
3869 					 new_dir, new_dentry);
3870 	}
3871 
3872 	return ext4_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
3873 }
3874 
3875 /*
3876  * directories can handle most operations...
3877  */
3878 const struct inode_operations ext4_dir_inode_operations = {
3879 	.create		= ext4_create,
3880 	.lookup		= ext4_lookup,
3881 	.link		= ext4_link,
3882 	.unlink		= ext4_unlink,
3883 	.symlink	= ext4_symlink,
3884 	.mkdir		= ext4_mkdir,
3885 	.rmdir		= ext4_rmdir,
3886 	.mknod		= ext4_mknod,
3887 	.tmpfile	= ext4_tmpfile,
3888 	.rename2	= ext4_rename2,
3889 	.setattr	= ext4_setattr,
3890 	.setxattr	= generic_setxattr,
3891 	.getxattr	= generic_getxattr,
3892 	.listxattr	= ext4_listxattr,
3893 	.removexattr	= generic_removexattr,
3894 	.get_acl	= ext4_get_acl,
3895 	.set_acl	= ext4_set_acl,
3896 	.fiemap         = ext4_fiemap,
3897 };
3898 
3899 const struct inode_operations ext4_special_inode_operations = {
3900 	.setattr	= ext4_setattr,
3901 	.setxattr	= generic_setxattr,
3902 	.getxattr	= generic_getxattr,
3903 	.listxattr	= ext4_listxattr,
3904 	.removexattr	= generic_removexattr,
3905 	.get_acl	= ext4_get_acl,
3906 	.set_acl	= ext4_set_acl,
3907 };
3908