1	// SPDX-License-Identifier: GPL-2.0
2	/*
3	* linux/fs/ext4/namei.c
4	*
5	* Copyright (C) 1992, 1993, 1994, 1995
6	* Remy Card (card@masi.ibp.fr)
7	* Laboratoire MASI - Institut Blaise Pascal
8	* Universite Pierre et Marie Curie (Paris VI)
9	*
10	* from
11	*
12	* linux/fs/minix/namei.c
13	*
14	* Copyright (C) 1991, 1992 Linus Torvalds
15	*
16	* Big-endian to little-endian byte-swapping/bitmaps by
17	* David S. Miller (davem@caip.rutgers.edu), 1995
18	* Directory entry file type support and forward compatibility hooks
19	* for B-tree directories by Theodore Ts'o (tytso@mit.edu), 1998
20	* Hash Tree Directory indexing (c)
21	* Daniel Phillips, 2001
22	* Hash Tree Directory indexing porting
23	* Christopher Li, 2002
24	* Hash Tree Directory indexing cleanup
25	* Theodore Ts'o, 2002
26	*/
27
28	#include <linux/fs.h>
29	#include <linux/pagemap.h>
30	#include <linux/time.h>
31	#include <linux/fcntl.h>
32	#include <linux/stat.h>
33	#include <linux/string.h>
34	#include <linux/quotaops.h>
35	#include <linux/buffer_head.h>
36	#include <linux/bio.h>
37	#include <linux/iversion.h>
38	#include <linux/unicode.h>
39	#include "ext4.h"
40	#include "ext4_jbd2.h"
41
42	#include "xattr.h"
43	#include "acl.h"
44
45	#include <trace/events/ext4.h>
46	/*
47	* define how far ahead to read directories while searching them.
48	*/
49	#define NAMEI_RA_CHUNKS 2
50	#define NAMEI_RA_BLOCKS 4
51	#define NAMEI_RA_SIZE (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
52
53	static struct buffer_head *ext4_append(handle_t *handle,
54	struct inode *inode,
55	ext4_lblk_t *block)
56	{
57	struct ext4_map_blocks map;
58	struct buffer_head *bh;
59	int err;
60
61	if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb &&
62	((inode->i_size >> 10) >=
63	EXT4_SB(inode->i_sb)->s_max_dir_size_kb)))
64	return ERR_PTR(error: -ENOSPC);
65
66	*block = inode->i_size >> inode->i_sb->s_blocksize_bits;
67	map.m_lblk = *block;
68	map.m_len = 1;
69
70	/*
71	* We're appending new directory block. Make sure the block is not
72	* allocated yet, otherwise we will end up corrupting the
73	* directory.
74	*/
75	err = ext4_map_blocks(NULL, inode, map: &map, flags: 0);
76	if (err < 0)
77	return ERR_PTR(error: err);
78	if (err) {
79	EXT4_ERROR_INODE(inode, "Logical block already allocated");
80	return ERR_PTR(error: -EFSCORRUPTED);
81	}
82
83	bh = ext4_bread(handle, inode, *block, EXT4_GET_BLOCKS_CREATE);
84	if (IS_ERR(ptr: bh))
85	return bh;
86	inode->i_size += inode->i_sb->s_blocksize;
87	EXT4_I(inode)->i_disksize = inode->i_size;
88	err = ext4_mark_inode_dirty(handle, inode);
89	if (err)
90	goto out;
91	BUFFER_TRACE(bh, "get_write_access");
92	err = ext4_journal_get_write_access(handle, inode->i_sb, bh,
93	EXT4_JTR_NONE);
94	if (err)
95	goto out;
96	return bh;
97
98	out:
99	brelse(bh);
100	ext4_std_error(inode->i_sb, err);
101	return ERR_PTR(error: err);
102	}
103
104	static int ext4_dx_csum_verify(struct inode *inode,
105	struct ext4_dir_entry *dirent);
106
107	/*
108	* Hints to ext4_read_dirblock regarding whether we expect a directory
109	* block being read to be an index block, or a block containing
110	* directory entries (and if the latter, whether it was found via a
111	* logical block in an htree index block). This is used to control
112	* what sort of sanity checkinig ext4_read_dirblock() will do on the
113	* directory block read from the storage device. EITHER will means
114	* the caller doesn't know what kind of directory block will be read,
115	* so no specific verification will be done.
116	*/
117	typedef enum {
118	EITHER, INDEX, DIRENT, DIRENT_HTREE
119	} dirblock_type_t;
120
121	#define ext4_read_dirblock(inode, block, type) \
122	__ext4_read_dirblock((inode), (block), (type), __func__, __LINE__)
123
124	static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
125	ext4_lblk_t block,
126	dirblock_type_t type,
127	const char *func,
128	unsigned int line)
129	{
130	struct buffer_head *bh;
131	struct ext4_dir_entry *dirent;
132	int is_dx_block = 0;
133
134	if (block >= inode->i_size >> inode->i_blkbits) {
135	ext4_error_inode(inode, func, line, block,
136	"Attempting to read directory block (%u) that is past i_size (%llu)",
137	block, inode->i_size);
138	return ERR_PTR(error: -EFSCORRUPTED);
139	}
140
141	if (ext4_simulate_fail(sb: inode->i_sb, EXT4_SIM_DIRBLOCK_EIO))
142	bh = ERR_PTR(error: -EIO);
143	else
144	bh = ext4_bread(NULL, inode, block, 0);
145	if (IS_ERR(ptr: bh)) {
146	__ext4_warning(inode->i_sb, func, line,
147	"inode #%lu: lblock %lu: comm %s: "
148	"error %ld reading directory block",
149	inode->i_ino, (unsigned long)block,
150	current->comm, PTR_ERR(ptr: bh));
151
152	return bh;
153	}
154	if (!bh && (type == INDEX || type == DIRENT_HTREE)) {
155	ext4_error_inode(inode, func, line, block,
156	"Directory hole found for htree %s block",
157	(type == INDEX) ? "index" : "leaf");
158	return ERR_PTR(error: -EFSCORRUPTED);
159	}
160	if (!bh)
161	return NULL;
162	dirent = (struct ext4_dir_entry *) bh->b_data;
163	/* Determine whether or not we have an index block */
164	if (is_dx(inode)) {
165	if (block == 0)
166	is_dx_block = 1;
167	else if (ext4_rec_len_from_disk(dlen: dirent->rec_len,
168	blocksize: inode->i_sb->s_blocksize) ==
169	inode->i_sb->s_blocksize)
170	is_dx_block = 1;
171	}
172	if (!is_dx_block && type == INDEX) {
173	ext4_error_inode(inode, func, line, block,
174	"directory leaf block found instead of index block");
175	brelse(bh);
176	return ERR_PTR(error: -EFSCORRUPTED);
177	}
178	if (!ext4_has_metadata_csum(sb: inode->i_sb) ||
179	buffer_verified(bh))
180	return bh;
181
182	/*
183	* An empty leaf block can get mistaken for a index block; for
184	* this reason, we can only check the index checksum when the
185	* caller is sure it should be an index block.
186	*/
187	if (is_dx_block && type == INDEX) {
188	if (ext4_dx_csum_verify(inode, dirent) &&
189	!ext4_simulate_fail(sb: inode->i_sb, EXT4_SIM_DIRBLOCK_CRC))
190	set_buffer_verified(bh);
191	else {
192	ext4_error_inode_err(inode, func, line, block,
193	EFSBADCRC,
194	"Directory index failed checksum");
195	brelse(bh);
196	return ERR_PTR(error: -EFSBADCRC);
197	}
198	}
199	if (!is_dx_block) {
200	if (ext4_dirblock_csum_verify(inode, bh) &&
201	!ext4_simulate_fail(sb: inode->i_sb, EXT4_SIM_DIRBLOCK_CRC))
202	set_buffer_verified(bh);
203	else {
204	ext4_error_inode_err(inode, func, line, block,
205	EFSBADCRC,
206	"Directory block failed checksum");
207	brelse(bh);
208	return ERR_PTR(error: -EFSBADCRC);
209	}
210	}
211	return bh;
212	}
213
214	#ifdef DX_DEBUG
215	#define dxtrace(command) command
216	#else
217	#define dxtrace(command)
218	#endif
219
220	struct fake_dirent
221	{
222	__le32 inode;
223	__le16 rec_len;
224	u8 name_len;
225	u8 file_type;
226	};
227
228	struct dx_countlimit
229	{
230	__le16 limit;
231	__le16 count;
232	};
233
234	struct dx_entry
235	{
236	__le32 hash;
237	__le32 block;
238	};
239
240	/*
241	* dx_root_info is laid out so that if it should somehow get overlaid by a
242	* dirent the two low bits of the hash version will be zero. Therefore, the
243	* hash version mod 4 should never be 0. Sincerely, the paranoia department.
244	*/
245
246	struct dx_root
247	{
248	struct fake_dirent dot;
249	char dot_name[4];
250	struct fake_dirent dotdot;
251	char dotdot_name[4];
252	struct dx_root_info
253	{
254	__le32 reserved_zero;
255	u8 hash_version;
256	u8 info_length; /* 8 */
257	u8 indirect_levels;
258	u8 unused_flags;
259	}
260	info;
261	struct dx_entry entries[];
262	};
263
264	struct dx_node
265	{
266	struct fake_dirent fake;
267	struct dx_entry entries[];
268	};
269
270
271	struct dx_frame
272	{
273	struct buffer_head *bh;
274	struct dx_entry *entries;
275	struct dx_entry *at;
276	};
277
278	struct dx_map_entry
279	{
280	u32 hash;
281	u16 offs;
282	u16 size;
283	};
284
285	/*
286	* This goes at the end of each htree block.
287	*/
288	struct dx_tail {
289	u32 dt_reserved;
290	__le32 dt_checksum; /* crc32c(uuid+inum+dirblock) */
291	};
292
293	static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
294	static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
295	static inline unsigned dx_get_hash(struct dx_entry *entry);
296	static void dx_set_hash(struct dx_entry *entry, unsigned value);
297	static unsigned dx_get_count(struct dx_entry *entries);
298	static unsigned dx_get_limit(struct dx_entry *entries);
299	static void dx_set_count(struct dx_entry *entries, unsigned value);
300	static void dx_set_limit(struct dx_entry *entries, unsigned value);
301	static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
302	static unsigned dx_node_limit(struct inode *dir);
303	static struct dx_frame *dx_probe(struct ext4_filename *fname,
304	struct inode *dir,
305	struct dx_hash_info *hinfo,
306	struct dx_frame *frame);
307	static void dx_release(struct dx_frame *frames);
308	static int dx_make_map(struct inode *dir, struct buffer_head *bh,
309	struct dx_hash_info *hinfo,
310	struct dx_map_entry *map_tail);
311	static void dx_sort_map(struct dx_map_entry *map, unsigned count);
312	static struct ext4_dir_entry_2 *dx_move_dirents(struct inode *dir, char *from,
313	char *to, struct dx_map_entry *offsets,
314	int count, unsigned int blocksize);
315	static struct ext4_dir_entry_2 *dx_pack_dirents(struct inode *dir, char *base,
316	unsigned int blocksize);
317	static void dx_insert_block(struct dx_frame *frame,
318	u32 hash, ext4_lblk_t block);
319	static int ext4_htree_next_block(struct inode *dir, __u32 hash,
320	struct dx_frame *frame,
321	struct dx_frame *frames,
322	__u32 *start_hash);
323	static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
324	struct ext4_filename *fname,
325	struct ext4_dir_entry_2 **res_dir);
326	static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
327	struct inode *dir, struct inode *inode);
328
329	/* checksumming functions */
330	void ext4_initialize_dirent_tail(struct buffer_head *bh,
331	unsigned int blocksize)
332	{
333	struct ext4_dir_entry_tail *t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
334
335	memset(t, 0, sizeof(struct ext4_dir_entry_tail));
336	t->det_rec_len = ext4_rec_len_to_disk(
337	len: sizeof(struct ext4_dir_entry_tail), blocksize);
338	t->det_reserved_ft = EXT4_FT_DIR_CSUM;
339	}
340
341	/* Walk through a dirent block to find a checksum "dirent" at the tail */
342	static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
343	struct buffer_head *bh)
344	{
345	struct ext4_dir_entry_tail *t;
346	int blocksize = EXT4_BLOCK_SIZE(inode->i_sb);
347
348	#ifdef PARANOID
349	struct ext4_dir_entry *d, *top;
350
351	d = (struct ext4_dir_entry *)bh->b_data;
352	top = (struct ext4_dir_entry *)(bh->b_data +
353	(blocksize - sizeof(struct ext4_dir_entry_tail)));
354	while (d < top && ext4_rec_len_from_disk(d->rec_len, blocksize))
355	d = (struct ext4_dir_entry *)(((void *)d) +
356	ext4_rec_len_from_disk(d->rec_len, blocksize));
357
358	if (d != top)
359	return NULL;
360
361	t = (struct ext4_dir_entry_tail *)d;
362	#else
363	t = EXT4_DIRENT_TAIL(bh->b_data, EXT4_BLOCK_SIZE(inode->i_sb));
364	#endif
365
366	if (t->det_reserved_zero1 ||
367	(ext4_rec_len_from_disk(dlen: t->det_rec_len, blocksize) !=
368	sizeof(struct ext4_dir_entry_tail)) ||
369	t->det_reserved_zero2 ||
370	t->det_reserved_ft != EXT4_FT_DIR_CSUM)
371	return NULL;
372
373	return t;
374	}
375
376	static __le32 ext4_dirblock_csum(struct inode *inode, void *dirent, int size)
377	{
378	struct ext4_sb_info *sbi = EXT4_SB(sb: inode->i_sb);
379	struct ext4_inode_info *ei = EXT4_I(inode);
380	__u32 csum;
381
382	csum = ext4_chksum(sbi, crc: ei->i_csum_seed, address: (__u8 *)dirent, length: size);
383	return cpu_to_le32(csum);
384	}
385
386	#define warn_no_space_for_csum(inode) \
387	__warn_no_space_for_csum((inode), __func__, __LINE__)
388
389	static void __warn_no_space_for_csum(struct inode *inode, const char *func,
390	unsigned int line)
391	{
392	__ext4_warning_inode(inode, function: func, line,
393	fmt: "No space for directory leaf checksum. Please run e2fsck -D.");
394	}
395
396	int ext4_dirblock_csum_verify(struct inode *inode, struct buffer_head *bh)
397	{
398	struct ext4_dir_entry_tail *t;
399
400	if (!ext4_has_metadata_csum(sb: inode->i_sb))
401	return 1;
402
403	t = get_dirent_tail(inode, bh);
404	if (!t) {
405	warn_no_space_for_csum(inode);
406	return 0;
407	}
408
409	if (t->det_checksum != ext4_dirblock_csum(inode, dirent: bh->b_data,
410	size: (char *)t - bh->b_data))
411	return 0;
412
413	return 1;
414	}
415
416	static void ext4_dirblock_csum_set(struct inode *inode,
417	struct buffer_head *bh)
418	{
419	struct ext4_dir_entry_tail *t;
420
421	if (!ext4_has_metadata_csum(sb: inode->i_sb))
422	return;
423
424	t = get_dirent_tail(inode, bh);
425	if (!t) {
426	warn_no_space_for_csum(inode);
427	return;
428	}
429
430	t->det_checksum = ext4_dirblock_csum(inode, dirent: bh->b_data,
431	size: (char *)t - bh->b_data);
432	}
433
434	int ext4_handle_dirty_dirblock(handle_t *handle,
435	struct inode *inode,
436	struct buffer_head *bh)
437	{
438	ext4_dirblock_csum_set(inode, bh);
439	return ext4_handle_dirty_metadata(handle, inode, bh);
440	}
441
442	static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
443	struct ext4_dir_entry *dirent,
444	int *offset)
445	{
446	struct ext4_dir_entry *dp;
447	struct dx_root_info *root;
448	int count_offset;
449	int blocksize = EXT4_BLOCK_SIZE(inode->i_sb);
450	unsigned int rlen = ext4_rec_len_from_disk(dlen: dirent->rec_len, blocksize);
451
452	if (rlen == blocksize)
453	count_offset = 8;
454	else if (rlen == 12) {
455	dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
456	if (ext4_rec_len_from_disk(dlen: dp->rec_len, blocksize) != blocksize - 12)
457	return NULL;
458	root = (struct dx_root_info *)(((void *)dp + 12));
459	if (root->reserved_zero ||
460	root->info_length != sizeof(struct dx_root_info))
461	return NULL;
462	count_offset = 32;
463	} else
464	return NULL;
465
466	if (offset)
467	*offset = count_offset;
468	return (struct dx_countlimit *)(((void *)dirent) + count_offset);
469	}
470
471	static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
472	int count_offset, int count, struct dx_tail *t)
473	{
474	struct ext4_sb_info *sbi = EXT4_SB(sb: inode->i_sb);
475	struct ext4_inode_info *ei = EXT4_I(inode);
476	__u32 csum;
477	int size;
478	__u32 dummy_csum = 0;
479	int offset = offsetof(struct dx_tail, dt_checksum);
480
481	size = count_offset + (count * sizeof(struct dx_entry));
482	csum = ext4_chksum(sbi, crc: ei->i_csum_seed, address: (__u8 *)dirent, length: size);
483	csum = ext4_chksum(sbi, crc: csum, address: (__u8 *)t, length: offset);
484	csum = ext4_chksum(sbi, crc: csum, address: (__u8 *)&dummy_csum, length: sizeof(dummy_csum));
485
486	return cpu_to_le32(csum);
487	}
488
489	static int ext4_dx_csum_verify(struct inode *inode,
490	struct ext4_dir_entry *dirent)
491	{
492	struct dx_countlimit *c;
493	struct dx_tail *t;
494	int count_offset, limit, count;
495
496	if (!ext4_has_metadata_csum(sb: inode->i_sb))
497	return 1;
498
499	c = get_dx_countlimit(inode, dirent, offset: &count_offset);
500	if (!c) {
501	EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
502	return 0;
503	}
504	limit = le16_to_cpu(c->limit);
505	count = le16_to_cpu(c->count);
506	if (count_offset + (limit * sizeof(struct dx_entry)) >
507	EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
508	warn_no_space_for_csum(inode);
509	return 0;
510	}
511	t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
512
513	if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
514	count, t))
515	return 0;
516	return 1;
517	}
518
519	static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
520	{
521	struct dx_countlimit *c;
522	struct dx_tail *t;
523	int count_offset, limit, count;
524
525	if (!ext4_has_metadata_csum(sb: inode->i_sb))
526	return;
527
528	c = get_dx_countlimit(inode, dirent, offset: &count_offset);
529	if (!c) {
530	EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
531	return;
532	}
533	limit = le16_to_cpu(c->limit);
534	count = le16_to_cpu(c->count);
535	if (count_offset + (limit * sizeof(struct dx_entry)) >
536	EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
537	warn_no_space_for_csum(inode);
538	return;
539	}
540	t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
541
542	t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
543	}
544
545	static inline int ext4_handle_dirty_dx_node(handle_t *handle,
546	struct inode *inode,
547	struct buffer_head *bh)
548	{
549	ext4_dx_csum_set(inode, dirent: (struct ext4_dir_entry *)bh->b_data);
550	return ext4_handle_dirty_metadata(handle, inode, bh);
551	}
552
553	/*
554	* p is at least 6 bytes before the end of page
555	*/
556	static inline struct ext4_dir_entry_2 *
557	ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
558	{
559	return (struct ext4_dir_entry_2 *)((char *)p +
560	ext4_rec_len_from_disk(dlen: p->rec_len, blocksize));
561	}
562
563	/*
564	* Future: use high four bits of block for coalesce-on-delete flags
565	* Mask them off for now.
566	*/
567
568	static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
569	{
570	return le32_to_cpu(entry->block) & 0x0fffffff;
571	}
572
573	static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
574	{
575	entry->block = cpu_to_le32(value);
576	}
577
578	static inline unsigned dx_get_hash(struct dx_entry *entry)
579	{
580	return le32_to_cpu(entry->hash);
581	}
582
583	static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
584	{
585	entry->hash = cpu_to_le32(value);
586	}
587
588	static inline unsigned dx_get_count(struct dx_entry *entries)
589	{
590	return le16_to_cpu(((struct dx_countlimit *) entries)->count);
591	}
592
593	static inline unsigned dx_get_limit(struct dx_entry *entries)
594	{
595	return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
596	}
597
598	static inline void dx_set_count(struct dx_entry *entries, unsigned value)
599	{
600	((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
601	}
602
603	static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
604	{
605	((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
606	}
607
608	static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
609	{
610	unsigned int entry_space = dir->i_sb->s_blocksize -
611	ext4_dir_rec_len(name_len: 1, NULL) -
612	ext4_dir_rec_len(name_len: 2, NULL) - infosize;
613
614	if (ext4_has_metadata_csum(sb: dir->i_sb))
615	entry_space -= sizeof(struct dx_tail);
616	return entry_space / sizeof(struct dx_entry);
617	}
618
619	static inline unsigned dx_node_limit(struct inode *dir)
620	{
621	unsigned int entry_space = dir->i_sb->s_blocksize -
622	ext4_dir_rec_len(name_len: 0, dir);
623
624	if (ext4_has_metadata_csum(sb: dir->i_sb))
625	entry_space -= sizeof(struct dx_tail);
626	return entry_space / sizeof(struct dx_entry);
627	}
628
629	/*
630	* Debug
631	*/
632	#ifdef DX_DEBUG
633	static void dx_show_index(char * label, struct dx_entry *entries)
634	{
635	int i, n = dx_get_count (entries);
636	printk(KERN_DEBUG "%s index", label);
637	for (i = 0; i < n; i++) {
638	printk(KERN_CONT " %x->%lu",
639	i ? dx_get_hash(entries + i) : 0,
640	(unsigned long)dx_get_block(entries + i));
641	}
642	printk(KERN_CONT "\n");
643	}
644
645	struct stats
646	{
647	unsigned names;
648	unsigned space;
649	unsigned bcount;
650	};
651
652	static struct stats dx_show_leaf(struct inode *dir,
653	struct dx_hash_info *hinfo,
654	struct ext4_dir_entry_2 *de,
655	int size, int show_names)
656	{
657	unsigned names = 0, space = 0;
658	char *base = (char *) de;
659	struct dx_hash_info h = *hinfo;
660
661	printk("names: ");
662	while ((char *) de < base + size)
663	{
664	if (de->inode)
665	{
666	if (show_names)
667	{
668	#ifdef CONFIG_FS_ENCRYPTION
669	int len;
670	char *name;
671	struct fscrypt_str fname_crypto_str =
672	FSTR_INIT(NULL, 0);
673	int res = 0;
674
675	name = de->name;
676	len = de->name_len;
677	if (!IS_ENCRYPTED(dir)) {
678	/* Directory is not encrypted */
679	(void) ext4fs_dirhash(dir, de->name,
680	de->name_len, &h);
681	printk("%*.s:(U)%x.%u ", len,
682	name, h.hash,
683	(unsigned) ((char *) de
684	- base));
685	} else {
686	struct fscrypt_str de_name =
687	FSTR_INIT(name, len);
688
689	/* Directory is encrypted */
690	res = fscrypt_fname_alloc_buffer(
691	len, &fname_crypto_str);
692	if (res)
693	printk(KERN_WARNING "Error "
694	"allocating crypto "
695	"buffer--skipping "
696	"crypto\n");
697	res = fscrypt_fname_disk_to_usr(dir,
698	0, 0, &de_name,
699	&fname_crypto_str);
700	if (res) {
701	printk(KERN_WARNING "Error "
702	"converting filename "
703	"from disk to usr"
704	"\n");
705	name = "??";
706	len = 2;
707	} else {
708	name = fname_crypto_str.name;
709	len = fname_crypto_str.len;
710	}
711	if (IS_CASEFOLDED(dir))
712	h.hash = EXT4_DIRENT_HASH(de);
713	else
714	(void) ext4fs_dirhash(dir,
715	de->name,
716	de->name_len, &h);
717	printk("%*.s:(E)%x.%u ", len, name,
718	h.hash, (unsigned) ((char *) de
719	- base));
720	fscrypt_fname_free_buffer(
721	&fname_crypto_str);
722	}
723	#else
724	int len = de->name_len;
725	char *name = de->name;
726	(void) ext4fs_dirhash(dir, de->name,
727	de->name_len, &h);
728	printk("%*.s:%x.%u ", len, name, h.hash,
729	(unsigned) ((char *) de - base));
730	#endif
731	}
732	space += ext4_dir_rec_len(de->name_len, dir);
733	names++;
734	}
735	de = ext4_next_entry(de, size);
736	}
737	printk(KERN_CONT "(%i)\n", names);
738	return (struct stats) { names, space, 1 };
739	}
740
741	struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
742	struct dx_entry *entries, int levels)
743	{
744	unsigned blocksize = dir->i_sb->s_blocksize;
745	unsigned count = dx_get_count(entries), names = 0, space = 0, i;
746	unsigned bcount = 0;
747	struct buffer_head *bh;
748	printk("%i indexed blocks...\n", count);
749	for (i = 0; i < count; i++, entries++)
750	{
751	ext4_lblk_t block = dx_get_block(entries);
752	ext4_lblk_t hash = i ? dx_get_hash(entries): 0;
753	u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
754	struct stats stats;
755	printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range);
756	bh = ext4_bread(NULL,dir, block, 0);
757	if (!bh || IS_ERR(bh))
758	continue;
759	stats = levels?
760	dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
761	dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *)
762	bh->b_data, blocksize, 0);
763	names += stats.names;
764	space += stats.space;
765	bcount += stats.bcount;
766	brelse(bh);
767	}
768	if (bcount)
769	printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
770	levels ? "" : " ", names, space/bcount,
771	(space/bcount)*100/blocksize);
772	return (struct stats) { names, space, bcount};
773	}
774
775	/*
776	* Linear search cross check
777	*/
778	static inline void htree_rep_invariant_check(struct dx_entry *at,
779	struct dx_entry *target,
780	u32 hash, unsigned int n)
781	{
782	while (n--) {
783	dxtrace(printk(KERN_CONT ","));
784	if (dx_get_hash(++at) > hash) {
785	at--;
786	break;
787	}
788	}
789	ASSERT(at == target - 1);
790	}
791	#else /* DX_DEBUG */
792	static inline void htree_rep_invariant_check(struct dx_entry *at,
793	struct dx_entry *target,
794	u32 hash, unsigned int n)
795	{
796	}
797	#endif /* DX_DEBUG */
798
799	/*
800	* Probe for a directory leaf block to search.
801	*
802	* dx_probe can return ERR_BAD_DX_DIR, which means there was a format
803	* error in the directory index, and the caller should fall back to
804	* searching the directory normally. The callers of dx_probe **MUST**
805	* check for this error code, and make sure it never gets reflected
806	* back to userspace.
807	*/
808	static struct dx_frame *
809	dx_probe(struct ext4_filename *fname, struct inode *dir,
810	struct dx_hash_info *hinfo, struct dx_frame *frame_in)
811	{
812	unsigned count, indirect, level, i;
813	struct dx_entry *at, *entries, *p, *q, *m;
814	struct dx_root *root;
815	struct dx_frame *frame = frame_in;
816	struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
817	u32 hash;
818	ext4_lblk_t block;
819	ext4_lblk_t blocks[EXT4_HTREE_LEVEL];
820
821	memset(frame_in, 0, EXT4_HTREE_LEVEL * sizeof(frame_in[0]));
822	frame->bh = ext4_read_dirblock(dir, 0, INDEX);
823	if (IS_ERR(ptr: frame->bh))
824	return (struct dx_frame *) frame->bh;
825
826	root = (struct dx_root *) frame->bh->b_data;
827	if (root->info.hash_version != DX_HASH_TEA &&
828	root->info.hash_version != DX_HASH_HALF_MD4 &&
829	root->info.hash_version != DX_HASH_LEGACY &&
830	root->info.hash_version != DX_HASH_SIPHASH) {
831	ext4_warning_inode(dir, "Unrecognised inode hash code %u",
832	root->info.hash_version);
833	goto fail;
834	}
835	if (ext4_hash_in_dirent(inode: dir)) {
836	if (root->info.hash_version != DX_HASH_SIPHASH) {
837	ext4_warning_inode(dir,
838	"Hash in dirent, but hash is not SIPHASH");
839	goto fail;
840	}
841	} else {
842	if (root->info.hash_version == DX_HASH_SIPHASH) {
843	ext4_warning_inode(dir,
844	"Hash code is SIPHASH, but hash not in dirent");
845	goto fail;
846	}
847	}
848	if (fname)
849	hinfo = &fname->hinfo;
850	hinfo->hash_version = root->info.hash_version;
851	if (hinfo->hash_version <= DX_HASH_TEA)
852	hinfo->hash_version += EXT4_SB(sb: dir->i_sb)->s_hash_unsigned;
853	hinfo->seed = EXT4_SB(sb: dir->i_sb)->s_hash_seed;
854	/* hash is already computed for encrypted casefolded directory */
855	if (fname && fname_name(fname) &&
856	!(IS_ENCRYPTED(dir) && IS_CASEFOLDED(dir))) {
857	int ret = ext4fs_dirhash(dir, fname_name(fname),
858	fname_len(fname), hinfo);
859	if (ret < 0) {
860	ret_err = ERR_PTR(error: ret);
861	goto fail;
862	}
863	}
864	hash = hinfo->hash;
865
866	if (root->info.unused_flags & 1) {
867	ext4_warning_inode(dir, "Unimplemented hash flags: %#06x",
868	root->info.unused_flags);
869	goto fail;
870	}
871
872	indirect = root->info.indirect_levels;
873	if (indirect >= ext4_dir_htree_level(sb: dir->i_sb)) {
874	ext4_warning(dir->i_sb,
875	"Directory (ino: %lu) htree depth %#06x exceed"
876	"supported value", dir->i_ino,
877	ext4_dir_htree_level(dir->i_sb));
878	if (ext4_dir_htree_level(sb: dir->i_sb) < EXT4_HTREE_LEVEL) {
879	ext4_warning(dir->i_sb, "Enable large directory "
880	"feature to access it");
881	}
882	goto fail;
883	}
884
885	entries = (struct dx_entry *)(((char *)&root->info) +
886	root->info.info_length);
887
888	if (dx_get_limit(entries) != dx_root_limit(dir,
889	infosize: root->info.info_length)) {
890	ext4_warning_inode(dir, "dx entry: limit %u != root limit %u",
891	dx_get_limit(entries),
892	dx_root_limit(dir, root->info.info_length));
893	goto fail;
894	}
895
896	dxtrace(printk("Look up %x", hash));
897	level = 0;
898	blocks[0] = 0;
899	while (1) {
900	count = dx_get_count(entries);
901	if (!count || count > dx_get_limit(entries)) {
902	ext4_warning_inode(dir,
903	"dx entry: count %u beyond limit %u",
904	count, dx_get_limit(entries));
905	goto fail;
906	}
907
908	p = entries + 1;
909	q = entries + count - 1;
910	while (p <= q) {
911	m = p + (q - p) / 2;
912	dxtrace(printk(KERN_CONT "."));
913	if (dx_get_hash(entry: m) > hash)
914	q = m - 1;
915	else
916	p = m + 1;
917	}
918
919	htree_rep_invariant_check(at: entries, target: p, hash, n: count - 1);
920
921	at = p - 1;
922	dxtrace(printk(KERN_CONT " %x->%u\n",
923	at == entries ? 0 : dx_get_hash(at),
924	dx_get_block(at)));
925	frame->entries = entries;
926	frame->at = at;
927
928	block = dx_get_block(entry: at);
929	for (i = 0; i <= level; i++) {
930	if (blocks[i] == block) {
931	ext4_warning_inode(dir,
932	"dx entry: tree cycle block %u points back to block %u",
933	blocks[level], block);
934	goto fail;
935	}
936	}
937	if (++level > indirect)
938	return frame;
939	blocks[level] = block;
940	frame++;
941	frame->bh = ext4_read_dirblock(dir, block, INDEX);
942	if (IS_ERR(ptr: frame->bh)) {
943	ret_err = (struct dx_frame *) frame->bh;
944	frame->bh = NULL;
945	goto fail;
946	}
947
948	entries = ((struct dx_node *) frame->bh->b_data)->entries;
949
950	if (dx_get_limit(entries) != dx_node_limit(dir)) {
951	ext4_warning_inode(dir,
952	"dx entry: limit %u != node limit %u",
953	dx_get_limit(entries), dx_node_limit(dir));
954	goto fail;
955	}
956	}
957	fail:
958	while (frame >= frame_in) {
959	brelse(bh: frame->bh);
960	frame--;
961	}
962
963	if (ret_err == ERR_PTR(ERR_BAD_DX_DIR))
964	ext4_warning_inode(dir,
965	"Corrupt directory, running e2fsck is recommended");
966	return ret_err;
967	}
968
969	static void dx_release(struct dx_frame *frames)
970	{
971	struct dx_root_info *info;
972	int i;
973	unsigned int indirect_levels;
974
975	if (frames[0].bh == NULL)
976	return;
977
978	info = &((struct dx_root *)frames[0].bh->b_data)->info;
979	/* save local copy, "info" may be freed after brelse() */
980	indirect_levels = info->indirect_levels;
981	for (i = 0; i <= indirect_levels; i++) {
982	if (frames[i].bh == NULL)
983	break;
984	brelse(bh: frames[i].bh);
985	frames[i].bh = NULL;
986	}
987	}
988
989	/*
990	* This function increments the frame pointer to search the next leaf
991	* block, and reads in the necessary intervening nodes if the search
992	* should be necessary. Whether or not the search is necessary is
993	* controlled by the hash parameter. If the hash value is even, then
994	* the search is only continued if the next block starts with that
995	* hash value. This is used if we are searching for a specific file.
996	*
997	* If the hash value is HASH_NB_ALWAYS, then always go to the next block.
998	*
999	* This function returns 1 if the caller should continue to search,
1000	* or 0 if it should not. If there is an error reading one of the
1001	* index blocks, it will a negative error code.
1002	*
1003	* If start_hash is non-null, it will be filled in with the starting
1004	* hash of the next page.
1005	*/
1006	static int ext4_htree_next_block(struct inode *dir, __u32 hash,
1007	struct dx_frame *frame,
1008	struct dx_frame *frames,
1009	__u32 *start_hash)
1010	{
1011	struct dx_frame *p;
1012	struct buffer_head *bh;
1013	int num_frames = 0;
1014	__u32 bhash;
1015
1016	p = frame;
1017	/*
1018	* Find the next leaf page by incrementing the frame pointer.
1019	* If we run out of entries in the interior node, loop around and
1020	* increment pointer in the parent node. When we break out of
1021	* this loop, num_frames indicates the number of interior
1022	* nodes need to be read.
1023	*/
1024	while (1) {
1025	if (++(p->at) < p->entries + dx_get_count(entries: p->entries))
1026	break;
1027	if (p == frames)
1028	return 0;
1029	num_frames++;
1030	p--;
1031	}
1032
1033	/*
1034	* If the hash is 1, then continue only if the next page has a
1035	* continuation hash of any value. This is used for readdir
1036	* handling. Otherwise, check to see if the hash matches the
1037	* desired continuation hash. If it doesn't, return since
1038	* there's no point to read in the successive index pages.
1039	*/
1040	bhash = dx_get_hash(entry: p->at);
1041	if (start_hash)
1042	*start_hash = bhash;
1043	if ((hash & 1) == 0) {
1044	if ((bhash & ~1) != hash)
1045	return 0;
1046	}
1047	/*
1048	* If the hash is HASH_NB_ALWAYS, we always go to the next
1049	* block so no check is necessary
1050	*/
1051	while (num_frames--) {
1052	bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX);
1053	if (IS_ERR(ptr: bh))
1054	return PTR_ERR(ptr: bh);
1055	p++;
1056	brelse(bh: p->bh);
1057	p->bh = bh;
1058	p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
1059	}
1060	return 1;
1061	}
1062
1063
1064	/*
1065	* This function fills a red-black tree with information from a
1066	* directory block. It returns the number directory entries loaded
1067	* into the tree. If there is an error it is returned in err.
1068	*/
1069	static int htree_dirblock_to_tree(struct file *dir_file,
1070	struct inode *dir, ext4_lblk_t block,
1071	struct dx_hash_info *hinfo,
1072	__u32 start_hash, __u32 start_minor_hash)
1073	{
1074	struct buffer_head *bh;
1075	struct ext4_dir_entry_2 *de, *top;
1076	int err = 0, count = 0;
1077	struct fscrypt_str fname_crypto_str = FSTR_INIT(NULL, 0), tmp_str;
1078	int csum = ext4_has_metadata_csum(sb: dir->i_sb);
1079
1080	dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
1081	(unsigned long)block));
1082	bh = ext4_read_dirblock(dir, block, DIRENT_HTREE);
1083	if (IS_ERR(ptr: bh))
1084	return PTR_ERR(ptr: bh);
1085
1086	de = (struct ext4_dir_entry_2 *) bh->b_data;
1087	/* csum entries are not larger in the casefolded encrypted case */
1088	top = (struct ext4_dir_entry_2 *) ((char *) de +
1089	dir->i_sb->s_blocksize -
1090	ext4_dir_rec_len(name_len: 0,
1091	dir: csum ? NULL : dir));
1092	/* Check if the directory is encrypted */
1093	if (IS_ENCRYPTED(dir)) {
1094	err = fscrypt_prepare_readdir(dir);
1095	if (err < 0) {
1096	brelse(bh);
1097	return err;
1098	}
1099	err = fscrypt_fname_alloc_buffer(EXT4_NAME_LEN,
1100	crypto_str: &fname_crypto_str);
1101	if (err < 0) {
1102	brelse(bh);
1103	return err;
1104	}
1105	}
1106
1107	for (; de < top; de = ext4_next_entry(p: de, blocksize: dir->i_sb->s_blocksize)) {
1108	if (ext4_check_dir_entry(dir, NULL, de, bh,
1109	bh->b_data, bh->b_size,
1110	(block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
1111	+ ((char *)de - bh->b_data))) {
1112	/* silently ignore the rest of the block */
1113	break;
1114	}
1115	if (ext4_hash_in_dirent(inode: dir)) {
1116	if (de->name_len && de->inode) {
1117	hinfo->hash = EXT4_DIRENT_HASH(de);
1118	hinfo->minor_hash = EXT4_DIRENT_MINOR_HASH(de);
1119	} else {
1120	hinfo->hash = 0;
1121	hinfo->minor_hash = 0;
1122	}
1123	} else {
1124	err = ext4fs_dirhash(dir, name: de->name,
1125	len: de->name_len, hinfo);
1126	if (err < 0) {
1127	count = err;
1128	goto errout;
1129	}
1130	}
1131	if ((hinfo->hash < start_hash) ||
1132	((hinfo->hash == start_hash) &&
1133	(hinfo->minor_hash < start_minor_hash)))
1134	continue;
1135	if (de->inode == 0)
1136	continue;
1137	if (!IS_ENCRYPTED(dir)) {
1138	tmp_str.name = de->name;
1139	tmp_str.len = de->name_len;
1140	err = ext4_htree_store_dirent(dir_file,
1141	hash: hinfo->hash, minor_hash: hinfo->minor_hash, dirent: de,
1142	ent_name: &tmp_str);
1143	} else {
1144	int save_len = fname_crypto_str.len;
1145	struct fscrypt_str de_name = FSTR_INIT(de->name,
1146	de->name_len);
1147
1148	/* Directory is encrypted */
1149	err = fscrypt_fname_disk_to_usr(inode: dir, hash: hinfo->hash,
1150	minor_hash: hinfo->minor_hash, iname: &de_name,
1151	oname: &fname_crypto_str);
1152	if (err) {
1153	count = err;
1154	goto errout;
1155	}
1156	err = ext4_htree_store_dirent(dir_file,
1157	hash: hinfo->hash, minor_hash: hinfo->minor_hash, dirent: de,
1158	ent_name: &fname_crypto_str);
1159	fname_crypto_str.len = save_len;
1160	}
1161	if (err != 0) {
1162	count = err;
1163	goto errout;
1164	}
1165	count++;
1166	}
1167	errout:
1168	brelse(bh);
1169	fscrypt_fname_free_buffer(crypto_str: &fname_crypto_str);
1170	return count;
1171	}
1172
1173
1174	/*
1175	* This function fills a red-black tree with information from a
1176	* directory. We start scanning the directory in hash order, starting
1177	* at start_hash and start_minor_hash.
1178	*
1179	* This function returns the number of entries inserted into the tree,
1180	* or a negative error code.
1181	*/
1182	int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1183	__u32 start_minor_hash, __u32 *next_hash)
1184	{
1185	struct dx_hash_info hinfo;
1186	struct ext4_dir_entry_2 *de;
1187	struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
1188	struct inode *dir;
1189	ext4_lblk_t block;
1190	int count = 0;
1191	int ret, err;
1192	__u32 hashval;
1193	struct fscrypt_str tmp_str;
1194
1195	dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
1196	start_hash, start_minor_hash));
1197	dir = file_inode(f: dir_file);
1198	if (!(ext4_test_inode_flag(inode: dir, bit: EXT4_INODE_INDEX))) {
1199	if (ext4_hash_in_dirent(inode: dir))
1200	hinfo.hash_version = DX_HASH_SIPHASH;
1201	else
1202	hinfo.hash_version =
1203	EXT4_SB(sb: dir->i_sb)->s_def_hash_version;
1204	if (hinfo.hash_version <= DX_HASH_TEA)
1205	hinfo.hash_version +=
1206	EXT4_SB(sb: dir->i_sb)->s_hash_unsigned;
1207	hinfo.seed = EXT4_SB(sb: dir->i_sb)->s_hash_seed;
1208	if (ext4_has_inline_data(inode: dir)) {
1209	int has_inline_data = 1;
1210	count = ext4_inlinedir_to_tree(dir_file, dir, block: 0,
1211	hinfo: &hinfo, start_hash,
1212	start_minor_hash,
1213	has_inline_data: &has_inline_data);
1214	if (has_inline_data) {
1215	*next_hash = ~0;
1216	return count;
1217	}
1218	}
1219	count = htree_dirblock_to_tree(dir_file, dir, block: 0, hinfo: &hinfo,
1220	start_hash, start_minor_hash);
1221	*next_hash = ~0;
1222	return count;
1223	}
1224	hinfo.hash = start_hash;
1225	hinfo.minor_hash = 0;
1226	frame = dx_probe(NULL, dir, hinfo: &hinfo, frame_in: frames);
1227	if (IS_ERR(ptr: frame))
1228	return PTR_ERR(ptr: frame);
1229
1230	/* Add '.' and '..' from the htree header */
1231	if (!start_hash && !start_minor_hash) {
1232	de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1233	tmp_str.name = de->name;
1234	tmp_str.len = de->name_len;
1235	err = ext4_htree_store_dirent(dir_file, hash: 0, minor_hash: 0,
1236	dirent: de, ent_name: &tmp_str);
1237	if (err != 0)
1238	goto errout;
1239	count++;
1240	}
1241	if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
1242	de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
1243	de = ext4_next_entry(p: de, blocksize: dir->i_sb->s_blocksize);
1244	tmp_str.name = de->name;
1245	tmp_str.len = de->name_len;
1246	err = ext4_htree_store_dirent(dir_file, hash: 2, minor_hash: 0,
1247	dirent: de, ent_name: &tmp_str);
1248	if (err != 0)
1249	goto errout;
1250	count++;
1251	}
1252
1253	while (1) {
1254	if (fatal_signal_pending(current)) {
1255	err = -ERESTARTSYS;
1256	goto errout;
1257	}
1258	cond_resched();
1259	block = dx_get_block(entry: frame->at);
1260	ret = htree_dirblock_to_tree(dir_file, dir, block, hinfo: &hinfo,
1261	start_hash, start_minor_hash);
1262	if (ret < 0) {
1263	err = ret;
1264	goto errout;
1265	}
1266	count += ret;
1267	hashval = ~0;
1268	ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
1269	frame, frames, start_hash: &hashval);
1270	*next_hash = hashval;
1271	if (ret < 0) {
1272	err = ret;
1273	goto errout;
1274	}
1275	/*
1276	* Stop if: (a) there are no more entries, or
1277	* (b) we have inserted at least one entry and the
1278	* next hash value is not a continuation
1279	*/
1280	if ((ret == 0) ||
1281	(count && ((hashval & 1) == 0)))
1282	break;
1283	}
1284	dx_release(frames);
1285	dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
1286	"next hash: %x\n", count, *next_hash));
1287	return count;
1288	errout:
1289	dx_release(frames);
1290	return (err);
1291	}
1292
1293	static inline int search_dirblock(struct buffer_head *bh,
1294	struct inode *dir,
1295	struct ext4_filename *fname,
1296	unsigned int offset,
1297	struct ext4_dir_entry_2 **res_dir)
1298	{
1299	return ext4_search_dir(bh, search_buf: bh->b_data, buf_size: dir->i_sb->s_blocksize, dir,
1300	fname, offset, res_dir);
1301	}
1302
1303	/*
1304	* Directory block splitting, compacting
1305	*/
1306
1307	/*
1308	* Create map of hash values, offsets, and sizes, stored at end of block.
1309	* Returns number of entries mapped.
1310	*/
1311	static int dx_make_map(struct inode *dir, struct buffer_head *bh,
1312	struct dx_hash_info *hinfo,
1313	struct dx_map_entry *map_tail)
1314	{
1315	int count = 0;
1316	struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)bh->b_data;
1317	unsigned int buflen = bh->b_size;
1318	char *base = bh->b_data;
1319	struct dx_hash_info h = *hinfo;
1320	int blocksize = EXT4_BLOCK_SIZE(dir->i_sb);
1321
1322	if (ext4_has_metadata_csum(sb: dir->i_sb))
1323	buflen -= sizeof(struct ext4_dir_entry_tail);
1324
1325	while ((char *) de < base + buflen) {
1326	if (ext4_check_dir_entry(dir, NULL, de, bh, base, buflen,
1327	((char *)de) - base))
1328	return -EFSCORRUPTED;
1329	if (de->name_len && de->inode) {
1330	if (ext4_hash_in_dirent(inode: dir))
1331	h.hash = EXT4_DIRENT_HASH(de);
1332	else {
1333	int err = ext4fs_dirhash(dir, name: de->name,
1334	len: de->name_len, hinfo: &h);
1335	if (err < 0)
1336	return err;
1337	}
1338	map_tail--;
1339	map_tail->hash = h.hash;
1340	map_tail->offs = ((char *) de - base)>>2;
1341	map_tail->size = ext4_rec_len_from_disk(dlen: de->rec_len,
1342	blocksize);
1343	count++;
1344	cond_resched();
1345	}
1346	de = ext4_next_entry(p: de, blocksize);
1347	}
1348	return count;
1349	}
1350
1351	/* Sort map by hash value */
1352	static void dx_sort_map (struct dx_map_entry *map, unsigned count)
1353	{
1354	struct dx_map_entry *p, *q, *top = map + count - 1;
1355	int more;
1356	/* Combsort until bubble sort doesn't suck */
1357	while (count > 2) {
1358	count = count*10/13;
1359	if (count - 9 < 2) /* 9, 10 -> 11 */
1360	count = 11;
1361	for (p = top, q = p - count; q >= map; p--, q--)
1362	if (p->hash < q->hash)
1363	swap(*p, *q);
1364	}
1365	/* Garden variety bubble sort */
1366	do {
1367	more = 0;
1368	q = top;
1369	while (q-- > map) {
1370	if (q[1].hash >= q[0].hash)
1371	continue;
1372	swap(*(q+1), *q);
1373	more = 1;
1374	}
1375	} while(more);
1376	}
1377
1378	static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
1379	{
1380	struct dx_entry *entries = frame->entries;
1381	struct dx_entry *old = frame->at, *new = old + 1;
1382	int count = dx_get_count(entries);
1383
1384	ASSERT(count < dx_get_limit(entries));
1385	ASSERT(old < entries + count);
1386	memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
1387	dx_set_hash(entry: new, value: hash);
1388	dx_set_block(entry: new, value: block);
1389	dx_set_count(entries, value: count + 1);
1390	}
1391
1392	#if IS_ENABLED(CONFIG_UNICODE)
1393	/*
1394	* Test whether a case-insensitive directory entry matches the filename
1395	* being searched for. If quick is set, assume the name being looked up
1396	* is already in the casefolded form.
1397	*
1398	* Returns: 0 if the directory entry matches, more than 0 if it
1399	* doesn't match or less than zero on error.
1400	*/
1401	static int ext4_ci_compare(const struct inode *parent, const struct qstr *name,
1402	u8 *de_name, size_t de_name_len, bool quick)
1403	{
1404	const struct super_block *sb = parent->i_sb;
1405	const struct unicode_map *um = sb->s_encoding;
1406	struct fscrypt_str decrypted_name = FSTR_INIT(NULL, de_name_len);
1407	struct qstr entry = QSTR_INIT(de_name, de_name_len);
1408	int ret;
1409
1410	if (IS_ENCRYPTED(parent)) {
1411	const struct fscrypt_str encrypted_name =
1412	FSTR_INIT(de_name, de_name_len);
1413
1414	decrypted_name.name = kmalloc(size: de_name_len, GFP_KERNEL);
1415	if (!decrypted_name.name)
1416	return -ENOMEM;
1417	ret = fscrypt_fname_disk_to_usr(inode: parent, hash: 0, minor_hash: 0, iname: &encrypted_name,
1418	oname: &decrypted_name);
1419	if (ret < 0)
1420	goto out;
1421	entry.name = decrypted_name.name;
1422	entry.len = decrypted_name.len;
1423	}
1424
1425	if (quick)
1426	ret = utf8_strncasecmp_folded(um, cf: name, s1: &entry);
1427	else
1428	ret = utf8_strncasecmp(um, s1: name, s2: &entry);
1429	if (ret < 0) {
1430	/* Handle invalid character sequence as either an error
1431	* or as an opaque byte sequence.
1432	*/
1433	if (sb_has_strict_encoding(sb))
1434	ret = -EINVAL;
1435	else if (name->len != entry.len)
1436	ret = 1;
1437	else
1438	ret = !!memcmp(p: name->name, q: entry.name, size: entry.len);
1439	}
1440	out:
1441	kfree(objp: decrypted_name.name);
1442	return ret;
1443	}
1444
1445	int ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname,
1446	struct ext4_filename *name)
1447	{
1448	struct fscrypt_str *cf_name = &name->cf_name;
1449	struct dx_hash_info *hinfo = &name->hinfo;
1450	int len;
1451
1452	if (!IS_CASEFOLDED(dir) ||
1453	(IS_ENCRYPTED(dir) && !fscrypt_has_encryption_key(inode: dir))) {
1454	cf_name->name = NULL;
1455	return 0;
1456	}
1457
1458	cf_name->name = kmalloc(EXT4_NAME_LEN, GFP_NOFS);
1459	if (!cf_name->name)
1460	return -ENOMEM;
1461
1462	len = utf8_casefold(um: dir->i_sb->s_encoding,
1463	str: iname, dest: cf_name->name,
1464	EXT4_NAME_LEN);
1465	if (len <= 0) {
1466	kfree(objp: cf_name->name);
1467	cf_name->name = NULL;
1468	}
1469	cf_name->len = (unsigned) len;
1470	if (!IS_ENCRYPTED(dir))
1471	return 0;
1472
1473	hinfo->hash_version = DX_HASH_SIPHASH;
1474	hinfo->seed = NULL;
1475	if (cf_name->name)
1476	return ext4fs_dirhash(dir, name: cf_name->name, len: cf_name->len, hinfo);
1477	else
1478	return ext4fs_dirhash(dir, name: iname->name, len: iname->len, hinfo);
1479	}
1480	#endif
1481
1482	/*
1483	* Test whether a directory entry matches the filename being searched for.
1484	*
1485	* Return: %true if the directory entry matches, otherwise %false.
1486	*/
1487	static bool ext4_match(struct inode *parent,
1488	const struct ext4_filename *fname,
1489	struct ext4_dir_entry_2 *de)
1490	{
1491	struct fscrypt_name f;
1492
1493	if (!de->inode)
1494	return false;
1495
1496	f.usr_fname = fname->usr_fname;
1497	f.disk_name = fname->disk_name;
1498	#ifdef CONFIG_FS_ENCRYPTION
1499	f.crypto_buf = fname->crypto_buf;
1500	#endif
1501
1502	#if IS_ENABLED(CONFIG_UNICODE)
1503	if (IS_CASEFOLDED(parent) &&
1504	(!IS_ENCRYPTED(parent) || fscrypt_has_encryption_key(inode: parent))) {
1505	if (fname->cf_name.name) {
1506	struct qstr cf = {.name = fname->cf_name.name,
1507	.len = fname->cf_name.len};
1508	if (IS_ENCRYPTED(parent)) {
1509	if (fname->hinfo.hash != EXT4_DIRENT_HASH(de) ||
1510	fname->hinfo.minor_hash !=
1511	EXT4_DIRENT_MINOR_HASH(de)) {
1512
1513	return false;
1514	}
1515	}
1516	return !ext4_ci_compare(parent, name: &cf, de_name: de->name,
1517	de_name_len: de->name_len, quick: true);
1518	}
1519	return !ext4_ci_compare(parent, name: fname->usr_fname, de_name: de->name,
1520	de_name_len: de->name_len, quick: false);
1521	}
1522	#endif
1523
1524	return fscrypt_match_name(fname: &f, de_name: de->name, de_name_len: de->name_len);
1525	}
1526
1527	/*
1528	* Returns 0 if not found, -1 on failure, and 1 on success
1529	*/
1530	int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
1531	struct inode *dir, struct ext4_filename *fname,
1532	unsigned int offset, struct ext4_dir_entry_2 **res_dir)
1533	{
1534	struct ext4_dir_entry_2 * de;
1535	char * dlimit;
1536	int de_len;
1537
1538	de = (struct ext4_dir_entry_2 *)search_buf;
1539	dlimit = search_buf + buf_size;
1540	while ((char *) de < dlimit - EXT4_BASE_DIR_LEN) {
1541	/* this code is executed quadratically often */
1542	/* do minimal checking `by hand' */
1543	if (de->name + de->name_len <= dlimit &&
1544	ext4_match(parent: dir, fname, de)) {
1545	/* found a match - just to be sure, do
1546	* a full check */
1547	if (ext4_check_dir_entry(dir, NULL, de, bh, search_buf,
1548	buf_size, offset))
1549	return -1;
1550	*res_dir = de;
1551	return 1;
1552	}
1553	/* prevent looping on a bad block */
1554	de_len = ext4_rec_len_from_disk(dlen: de->rec_len,
1555	blocksize: dir->i_sb->s_blocksize);
1556	if (de_len <= 0)
1557	return -1;
1558	offset += de_len;
1559	de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
1560	}
1561	return 0;
1562	}
1563
1564	static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
1565	struct ext4_dir_entry *de)
1566	{
1567	struct super_block *sb = dir->i_sb;
1568
1569	if (!is_dx(dir))
1570	return 0;
1571	if (block == 0)
1572	return 1;
1573	if (de->inode == 0 &&
1574	ext4_rec_len_from_disk(dlen: de->rec_len, blocksize: sb->s_blocksize) ==
1575	sb->s_blocksize)
1576	return 1;
1577	return 0;
1578	}
1579
1580	/*
1581	* __ext4_find_entry()
1582	*
1583	* finds an entry in the specified directory with the wanted name. It
1584	* returns the cache buffer in which the entry was found, and the entry
1585	* itself (as a parameter - res_dir). It does NOT read the inode of the
1586	* entry - you'll have to do that yourself if you want to.
1587	*
1588	* The returned buffer_head has ->b_count elevated. The caller is expected
1589	* to brelse() it when appropriate.
1590	*/
1591	static struct buffer_head *__ext4_find_entry(struct inode *dir,
1592	struct ext4_filename *fname,
1593	struct ext4_dir_entry_2 **res_dir,
1594	int *inlined)
1595	{
1596	struct super_block *sb;
1597	struct buffer_head *bh_use[NAMEI_RA_SIZE];
1598	struct buffer_head *bh, *ret = NULL;
1599	ext4_lblk_t start, block;
1600	const u8 *name = fname->usr_fname->name;
1601	size_t ra_max = 0; /* Number of bh's in the readahead
1602	buffer, bh_use[] */
1603	size_t ra_ptr = 0; /* Current index into readahead
1604	buffer */
1605	ext4_lblk_t nblocks;
1606	int i, namelen, retval;
1607
1608	*res_dir = NULL;
1609	sb = dir->i_sb;
1610	namelen = fname->usr_fname->len;
1611	if (namelen > EXT4_NAME_LEN)
1612	return NULL;
1613
1614	if (ext4_has_inline_data(inode: dir)) {
1615	int has_inline_data = 1;
1616	ret = ext4_find_inline_entry(dir, fname, res_dir,
1617	has_inline_data: &has_inline_data);
1618	if (inlined)
1619	*inlined = has_inline_data;
1620	if (has_inline_data)
1621	goto cleanup_and_exit;
1622	}
1623
1624	if ((namelen <= 2) && (name[0] == '.') &&
1625	(name[1] == '.' || name[1] == '\0')) {
1626	/*
1627	* "." or ".." will only be in the first block
1628	* NFS may look up ".."; "." should be handled by the VFS
1629	*/
1630	block = start = 0;
1631	nblocks = 1;
1632	goto restart;
1633	}
1634	if (is_dx(dir)) {
1635	ret = ext4_dx_find_entry(dir, fname, res_dir);
1636	/*
1637	* On success, or if the error was file not found,
1638	* return. Otherwise, fall back to doing a search the
1639	* old fashioned way.
1640	*/
1641	if (!IS_ERR(ptr: ret) || PTR_ERR(ptr: ret) != ERR_BAD_DX_DIR)
1642	goto cleanup_and_exit;
1643	dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
1644	"falling back\n"));
1645	ret = NULL;
1646	}
1647	nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1648	if (!nblocks) {
1649	ret = NULL;
1650	goto cleanup_and_exit;
1651	}
1652	start = EXT4_I(dir)->i_dir_start_lookup;
1653	if (start >= nblocks)
1654	start = 0;
1655	block = start;
1656	restart:
1657	do {
1658	/*
1659	* We deal with the read-ahead logic here.
1660	*/
1661	cond_resched();
1662	if (ra_ptr >= ra_max) {
1663	/* Refill the readahead buffer */
1664	ra_ptr = 0;
1665	if (block < start)
1666	ra_max = start - block;
1667	else
1668	ra_max = nblocks - block;
1669	ra_max = min(ra_max, ARRAY_SIZE(bh_use));
1670	retval = ext4_bread_batch(inode: dir, block, bh_count: ra_max,
1671	wait: false /* wait */, bhs: bh_use);
1672	if (retval) {
1673	ret = ERR_PTR(error: retval);
1674	ra_max = 0;
1675	goto cleanup_and_exit;
1676	}
1677	}
1678	if ((bh = bh_use[ra_ptr++]) == NULL)
1679	goto next;
1680	wait_on_buffer(bh);
1681	if (!buffer_uptodate(bh)) {
1682	EXT4_ERROR_INODE_ERR(dir, EIO,
1683	"reading directory lblock %lu",
1684	(unsigned long) block);
1685	brelse(bh);
1686	ret = ERR_PTR(error: -EIO);
1687	goto cleanup_and_exit;
1688	}
1689	if (!buffer_verified(bh) &&
1690	!is_dx_internal_node(dir, block,
1691	de: (struct ext4_dir_entry *)bh->b_data) &&
1692	!ext4_dirblock_csum_verify(inode: dir, bh)) {
1693	EXT4_ERROR_INODE_ERR(dir, EFSBADCRC,
1694	"checksumming directory "
1695	"block %lu", (unsigned long)block);
1696	brelse(bh);
1697	ret = ERR_PTR(error: -EFSBADCRC);
1698	goto cleanup_and_exit;
1699	}
1700	set_buffer_verified(bh);
1701	i = search_dirblock(bh, dir, fname,
1702	offset: block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
1703	if (i == 1) {
1704	EXT4_I(dir)->i_dir_start_lookup = block;
1705	ret = bh;
1706	goto cleanup_and_exit;
1707	} else {
1708	brelse(bh);
1709	if (i < 0)
1710	goto cleanup_and_exit;
1711	}
1712	next:
1713	if (++block >= nblocks)
1714	block = 0;
1715	} while (block != start);
1716
1717	/*
1718	* If the directory has grown while we were searching, then
1719	* search the last part of the directory before giving up.
1720	*/
1721	block = nblocks;
1722	nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
1723	if (block < nblocks) {
1724	start = 0;
1725	goto restart;
1726	}
1727
1728	cleanup_and_exit:
1729	/* Clean up the read-ahead blocks */
1730	for (; ra_ptr < ra_max; ra_ptr++)
1731	brelse(bh: bh_use[ra_ptr]);
1732	return ret;
1733	}
1734
1735	static struct buffer_head *ext4_find_entry(struct inode *dir,
1736	const struct qstr *d_name,
1737	struct ext4_dir_entry_2 **res_dir,
1738	int *inlined)
1739	{
1740	int err;
1741	struct ext4_filename fname;
1742	struct buffer_head *bh;
1743
1744	err = ext4_fname_setup_filename(dir, iname: d_name, lookup: 1, fname: &fname);
1745	if (err == -ENOENT)
1746	return NULL;
1747	if (err)
1748	return ERR_PTR(error: err);
1749
1750	bh = __ext4_find_entry(dir, fname: &fname, res_dir, inlined);
1751
1752	ext4_fname_free_filename(fname: &fname);
1753	return bh;
1754	}
1755
1756	static struct buffer_head *ext4_lookup_entry(struct inode *dir,
1757	struct dentry *dentry,
1758	struct ext4_dir_entry_2 **res_dir)
1759	{
1760	int err;
1761	struct ext4_filename fname;
1762	struct buffer_head *bh;
1763
1764	err = ext4_fname_prepare_lookup(dir, dentry, fname: &fname);
1765	if (err == -ENOENT)
1766	return NULL;
1767	if (err)
1768	return ERR_PTR(error: err);
1769
1770	bh = __ext4_find_entry(dir, fname: &fname, res_dir, NULL);
1771
1772	ext4_fname_free_filename(fname: &fname);
1773	return bh;
1774	}
1775
1776	static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
1777	struct ext4_filename *fname,
1778	struct ext4_dir_entry_2 **res_dir)
1779	{
1780	struct super_block * sb = dir->i_sb;
1781	struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
1782	struct buffer_head *bh;
1783	ext4_lblk_t block;
1784	int retval;
1785
1786	#ifdef CONFIG_FS_ENCRYPTION
1787	*res_dir = NULL;
1788	#endif
1789	frame = dx_probe(fname, dir, NULL, frame_in: frames);
1790	if (IS_ERR(ptr: frame))
1791	return (struct buffer_head *) frame;
1792	do {
1793	block = dx_get_block(entry: frame->at);
1794	bh = ext4_read_dirblock(dir, block, DIRENT_HTREE);
1795	if (IS_ERR(ptr: bh))
1796	goto errout;
1797
1798	retval = search_dirblock(bh, dir, fname,
1799	offset: block << EXT4_BLOCK_SIZE_BITS(sb),
1800	res_dir);
1801	if (retval == 1)
1802	goto success;
1803	brelse(bh);
1804	if (retval == -1) {
1805	bh = ERR_PTR(ERR_BAD_DX_DIR);
1806	goto errout;
1807	}
1808
1809	/* Check to see if we should continue to search */
1810	retval = ext4_htree_next_block(dir, hash: fname->hinfo.hash, frame,
1811	frames, NULL);
1812	if (retval < 0) {
1813	ext4_warning_inode(dir,
1814	"error %d reading directory index block",
1815	retval);
1816	bh = ERR_PTR(error: retval);
1817	goto errout;
1818	}
1819	} while (retval == 1);
1820
1821	bh = NULL;
1822	errout:
1823	dxtrace(printk(KERN_DEBUG "%s not found\n", fname->usr_fname->name));
1824	success:
1825	dx_release(frames);
1826	return bh;
1827	}
1828
1829	static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
1830	{
1831	struct inode *inode;
1832	struct ext4_dir_entry_2 *de;
1833	struct buffer_head *bh;
1834
1835	if (dentry->d_name.len > EXT4_NAME_LEN)
1836	return ERR_PTR(error: -ENAMETOOLONG);
1837
1838	bh = ext4_lookup_entry(dir, dentry, res_dir: &de);
1839	if (IS_ERR(ptr: bh))
1840	return ERR_CAST(ptr: bh);
1841	inode = NULL;
1842	if (bh) {
1843	__u32 ino = le32_to_cpu(de->inode);
1844	brelse(bh);
1845	if (!ext4_valid_inum(sb: dir->i_sb, ino)) {
1846	EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
1847	return ERR_PTR(error: -EFSCORRUPTED);
1848	}
1849	if (unlikely(ino == dir->i_ino)) {
1850	EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir",
1851	dentry);
1852	return ERR_PTR(error: -EFSCORRUPTED);
1853	}
1854	inode = ext4_iget(dir->i_sb, ino, EXT4_IGET_NORMAL);
1855	if (inode == ERR_PTR(error: -ESTALE)) {
1856	EXT4_ERROR_INODE(dir,
1857	"deleted inode referenced: %u",
1858	ino);
1859	return ERR_PTR(error: -EFSCORRUPTED);
1860	}
1861	if (!IS_ERR(ptr: inode) && IS_ENCRYPTED(dir) &&
1862	(S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) &&
1863	!fscrypt_has_permitted_context(parent: dir, child: inode)) {
1864	ext4_warning(inode->i_sb,
1865	"Inconsistent encryption contexts: %lu/%lu",
1866	dir->i_ino, inode->i_ino);
1867	iput(inode);
1868	return ERR_PTR(error: -EPERM);
1869	}
1870	}
1871
1872	#if IS_ENABLED(CONFIG_UNICODE)
1873	if (!inode && IS_CASEFOLDED(dir)) {
1874	/* Eventually we want to call d_add_ci(dentry, NULL)
1875	* for negative dentries in the encoding case as
1876	* well. For now, prevent the negative dentry
1877	* from being cached.
1878	*/
1879	return NULL;
1880	}
1881	#endif
1882	return d_splice_alias(inode, dentry);
1883	}
1884
1885
1886	struct dentry *ext4_get_parent(struct dentry *child)
1887	{
1888	__u32 ino;
1889	struct ext4_dir_entry_2 * de;
1890	struct buffer_head *bh;
1891
1892	bh = ext4_find_entry(dir: d_inode(dentry: child), d_name: &dotdot_name, res_dir: &de, NULL);
1893	if (IS_ERR(ptr: bh))
1894	return ERR_CAST(ptr: bh);
1895	if (!bh)
1896	return ERR_PTR(error: -ENOENT);
1897	ino = le32_to_cpu(de->inode);
1898	brelse(bh);
1899
1900	if (!ext4_valid_inum(sb: child->d_sb, ino)) {
1901	EXT4_ERROR_INODE(d_inode(child),
1902	"bad parent inode number: %u", ino);
1903	return ERR_PTR(error: -EFSCORRUPTED);
1904	}
1905
1906	return d_obtain_alias(ext4_iget(child->d_sb, ino, EXT4_IGET_NORMAL));
1907	}
1908
1909	/*
1910	* Move count entries from end of map between two memory locations.
1911	* Returns pointer to last entry moved.
1912	*/
1913	static struct ext4_dir_entry_2 *
1914	dx_move_dirents(struct inode *dir, char *from, char *to,
1915	struct dx_map_entry *map, int count,
1916	unsigned blocksize)
1917	{
1918	unsigned rec_len = 0;
1919
1920	while (count--) {
1921	struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
1922	(from + (map->offs<<2));
1923	rec_len = ext4_dir_rec_len(name_len: de->name_len, dir);
1924
1925	memcpy (to, de, rec_len);
1926	((struct ext4_dir_entry_2 *) to)->rec_len =
1927	ext4_rec_len_to_disk(len: rec_len, blocksize);
1928
1929	/* wipe dir_entry excluding the rec_len field */
1930	de->inode = 0;
1931	memset(&de->name_len, 0, ext4_rec_len_from_disk(de->rec_len,
1932	blocksize) -
1933	offsetof(struct ext4_dir_entry_2,
1934	name_len));
1935
1936	map++;
1937	to += rec_len;
1938	}
1939	return (struct ext4_dir_entry_2 *) (to - rec_len);
1940	}
1941
1942	/*
1943	* Compact each dir entry in the range to the minimal rec_len.
1944	* Returns pointer to last entry in range.
1945	*/
1946	static struct ext4_dir_entry_2 *dx_pack_dirents(struct inode *dir, char *base,
1947	unsigned int blocksize)
1948	{
1949	struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1950	unsigned rec_len = 0;
1951
1952	prev = to = de;
1953	while ((char*)de < base + blocksize) {
1954	next = ext4_next_entry(p: de, blocksize);
1955	if (de->inode && de->name_len) {
1956	rec_len = ext4_dir_rec_len(name_len: de->name_len, dir);
1957	if (de > to)
1958	memmove(to, de, rec_len);
1959	to->rec_len = ext4_rec_len_to_disk(len: rec_len, blocksize);
1960	prev = to;
1961	to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1962	}
1963	de = next;
1964	}
1965	return prev;
1966	}
1967
1968	/*
1969	* Split a full leaf block to make room for a new dir entry.
1970	* Allocate a new block, and move entries so that they are approx. equally full.
1971	* Returns pointer to de in block into which the new entry will be inserted.
1972	*/
1973	static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1974	struct buffer_head **bh,struct dx_frame *frame,
1975	struct dx_hash_info *hinfo)
1976	{
1977	unsigned blocksize = dir->i_sb->s_blocksize;
1978	unsigned continued;
1979	int count;
1980	struct buffer_head *bh2;
1981	ext4_lblk_t newblock;
1982	u32 hash2;
1983	struct dx_map_entry *map;
1984	char *data1 = (*bh)->b_data, *data2;
1985	unsigned split, move, size;
1986	struct ext4_dir_entry_2 *de = NULL, *de2;
1987	int csum_size = 0;
1988	int err = 0, i;
1989
1990	if (ext4_has_metadata_csum(sb: dir->i_sb))
1991	csum_size = sizeof(struct ext4_dir_entry_tail);
1992
1993	bh2 = ext4_append(handle, inode: dir, block: &newblock);
1994	if (IS_ERR(ptr: bh2)) {
1995	brelse(bh: *bh);
1996	*bh = NULL;
1997	return (struct ext4_dir_entry_2 *) bh2;
1998	}
1999
2000	BUFFER_TRACE(*bh, "get_write_access");
2001	err = ext4_journal_get_write_access(handle, dir->i_sb, *bh,
2002	EXT4_JTR_NONE);
2003	if (err)
2004	goto journal_error;
2005
2006	BUFFER_TRACE(frame->bh, "get_write_access");
2007	err = ext4_journal_get_write_access(handle, dir->i_sb, frame->bh,
2008	EXT4_JTR_NONE);
2009	if (err)
2010	goto journal_error;
2011
2012	data2 = bh2->b_data;
2013
2014	/* create map in the end of data2 block */
2015	map = (struct dx_map_entry *) (data2 + blocksize);
2016	count = dx_make_map(dir, bh: *bh, hinfo, map_tail: map);
2017	if (count < 0) {
2018	err = count;
2019	goto journal_error;
2020	}
2021	map -= count;
2022	dx_sort_map(map, count);
2023	/* Ensure that neither split block is over half full */
2024	size = 0;
2025	move = 0;
2026	for (i = count-1; i >= 0; i--) {
2027	/* is more than half of this entry in 2nd half of the block? */
2028	if (size + map[i].size/2 > blocksize/2)
2029	break;
2030	size += map[i].size;
2031	move++;
2032	}
2033	/*
2034	* map index at which we will split
2035	*
2036	* If the sum of active entries didn't exceed half the block size, just
2037	* split it in half by count; each resulting block will have at least
2038	* half the space free.
2039	*/
2040	if (i > 0)
2041	split = count - move;
2042	else
2043	split = count/2;
2044
2045	hash2 = map[split].hash;
2046	continued = hash2 == map[split - 1].hash;
2047	dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
2048	(unsigned long)dx_get_block(frame->at),
2049	hash2, split, count-split));
2050
2051	/* Fancy dance to stay within two buffers */
2052	de2 = dx_move_dirents(dir, from: data1, to: data2, map: map + split, count: count - split,
2053	blocksize);
2054	de = dx_pack_dirents(dir, base: data1, blocksize);
2055	de->rec_len = ext4_rec_len_to_disk(len: data1 + (blocksize - csum_size) -
2056	(char *) de,
2057	blocksize);
2058	de2->rec_len = ext4_rec_len_to_disk(len: data2 + (blocksize - csum_size) -
2059	(char *) de2,
2060	blocksize);
2061	if (csum_size) {
2062	ext4_initialize_dirent_tail(bh: *bh, blocksize);
2063	ext4_initialize_dirent_tail(bh: bh2, blocksize);
2064	}
2065
2066	dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1,
2067	blocksize, 1));
2068	dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2,
2069	blocksize, 1));
2070
2071	/* Which block gets the new entry? */
2072	if (hinfo->hash >= hash2) {
2073	swap(*bh, bh2);
2074	de = de2;
2075	}
2076	dx_insert_block(frame, hash: hash2 + continued, block: newblock);
2077	err = ext4_handle_dirty_dirblock(handle, inode: dir, bh: bh2);
2078	if (err)
2079	goto journal_error;
2080	err = ext4_handle_dirty_dx_node(handle, inode: dir, bh: frame->bh);
2081	if (err)
2082	goto journal_error;
2083	brelse(bh: bh2);
2084	dxtrace(dx_show_index("frame", frame->entries));
2085	return de;
2086
2087	journal_error:
2088	brelse(bh: *bh);
2089	brelse(bh: bh2);
2090	*bh = NULL;
2091	ext4_std_error(dir->i_sb, err);
2092	return ERR_PTR(error: err);
2093	}
2094
2095	int ext4_find_dest_de(struct inode *dir, struct inode *inode,
2096	struct buffer_head *bh,
2097	void *buf, int buf_size,
2098	struct ext4_filename *fname,
2099	struct ext4_dir_entry_2 **dest_de)
2100	{
2101	struct ext4_dir_entry_2 *de;
2102	unsigned short reclen = ext4_dir_rec_len(fname_len(fname), dir);
2103	int nlen, rlen;
2104	unsigned int offset = 0;
2105	char *top;
2106
2107	de = buf;
2108	top = buf + buf_size - reclen;
2109	while ((char *) de <= top) {
2110	if (ext4_check_dir_entry(dir, NULL, de, bh,
2111	buf, buf_size, offset))
2112	return -EFSCORRUPTED;
2113	if (ext4_match(parent: dir, fname, de))
2114	return -EEXIST;
2115	nlen = ext4_dir_rec_len(name_len: de->name_len, dir);
2116	rlen = ext4_rec_len_from_disk(dlen: de->rec_len, blocksize: buf_size);
2117	if ((de->inode ? rlen - nlen : rlen) >= reclen)
2118	break;
2119	de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
2120	offset += rlen;
2121	}
2122	if ((char *) de > top)
2123	return -ENOSPC;
2124
2125	*dest_de = de;
2126	return 0;
2127	}
2128
2129	void ext4_insert_dentry(struct inode *dir,
2130	struct inode *inode,
2131	struct ext4_dir_entry_2 *de,
2132	int buf_size,
2133	struct ext4_filename *fname)
2134	{
2135
2136	int nlen, rlen;
2137
2138	nlen = ext4_dir_rec_len(name_len: de->name_len, dir);
2139	rlen = ext4_rec_len_from_disk(dlen: de->rec_len, blocksize: buf_size);
2140	if (de->inode) {
2141	struct ext4_dir_entry_2 *de1 =
2142	(struct ext4_dir_entry_2 *)((char *)de + nlen);
2143	de1->rec_len = ext4_rec_len_to_disk(len: rlen - nlen, blocksize: buf_size);
2144	de->rec_len = ext4_rec_len_to_disk(len: nlen, blocksize: buf_size);
2145	de = de1;
2146	}
2147	de->file_type = EXT4_FT_UNKNOWN;
2148	de->inode = cpu_to_le32(inode->i_ino);
2149	ext4_set_de_type(sb: inode->i_sb, de, mode: inode->i_mode);
2150	de->name_len = fname_len(fname);
2151	memcpy(de->name, fname_name(fname), fname_len(fname));
2152	if (ext4_hash_in_dirent(inode: dir)) {
2153	struct dx_hash_info *hinfo = &fname->hinfo;
2154
2155	EXT4_DIRENT_HASHES(de)->hash = cpu_to_le32(hinfo->hash);
2156	EXT4_DIRENT_HASHES(de)->minor_hash =
2157	cpu_to_le32(hinfo->minor_hash);
2158	}
2159	}
2160
2161	/*
2162	* Add a new entry into a directory (leaf) block. If de is non-NULL,
2163	* it points to a directory entry which is guaranteed to be large
2164	* enough for new directory entry. If de is NULL, then
2165	* add_dirent_to_buf will attempt search the directory block for
2166	* space. It will return -ENOSPC if no space is available, and -EIO
2167	* and -EEXIST if directory entry already exists.
2168	*/
2169	static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
2170	struct inode *dir,
2171	struct inode *inode, struct ext4_dir_entry_2 *de,
2172	struct buffer_head *bh)
2173	{
2174	unsigned int blocksize = dir->i_sb->s_blocksize;
2175	int csum_size = 0;
2176	int err, err2;
2177
2178	if (ext4_has_metadata_csum(sb: inode->i_sb))
2179	csum_size = sizeof(struct ext4_dir_entry_tail);
2180
2181	if (!de) {
2182	err = ext4_find_dest_de(dir, inode, bh, buf: bh->b_data,
2183	buf_size: blocksize - csum_size, fname, dest_de: &de);
2184	if (err)
2185	return err;
2186	}
2187	BUFFER_TRACE(bh, "get_write_access");
2188	err = ext4_journal_get_write_access(handle, dir->i_sb, bh,
2189	EXT4_JTR_NONE);
2190	if (err) {
2191	ext4_std_error(dir->i_sb, err);
2192	return err;
2193	}
2194
2195	/* By now the buffer is marked for journaling */
2196	ext4_insert_dentry(dir, inode, de, buf_size: blocksize, fname);
2197
2198	/*
2199	* XXX shouldn't update any times until successful
2200	* completion of syscall, but too many callers depend
2201	* on this.
2202	*
2203	* XXX similarly, too many callers depend on
2204	* ext4_new_inode() setting the times, but error
2205	* recovery deletes the inode, so the worst that can
2206	* happen is that the times are slightly out of date
2207	* and/or different from the directory change time.
2208	*/
2209	inode_set_mtime_to_ts(inode: dir, ts: inode_set_ctime_current(inode: dir));
2210	ext4_update_dx_flag(inode: dir);
2211	inode_inc_iversion(inode: dir);
2212	err2 = ext4_mark_inode_dirty(handle, dir);
2213	BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2214	err = ext4_handle_dirty_dirblock(handle, inode: dir, bh);
2215	if (err)
2216	ext4_std_error(dir->i_sb, err);
2217	return err ? err : err2;
2218	}
2219
2220	/*
2221	* This converts a one block unindexed directory to a 3 block indexed
2222	* directory, and adds the dentry to the indexed directory.
2223	*/
2224	static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
2225	struct inode *dir,
2226	struct inode *inode, struct buffer_head *bh)
2227	{
2228	struct buffer_head *bh2;
2229	struct dx_root *root;
2230	struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
2231	struct dx_entry *entries;
2232	struct ext4_dir_entry_2 *de, *de2;
2233	char *data2, *top;
2234	unsigned len;
2235	int retval;
2236	unsigned blocksize;
2237	ext4_lblk_t block;
2238	struct fake_dirent *fde;
2239	int csum_size = 0;
2240
2241	if (ext4_has_metadata_csum(sb: inode->i_sb))
2242	csum_size = sizeof(struct ext4_dir_entry_tail);
2243
2244	blocksize = dir->i_sb->s_blocksize;
2245	dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
2246	BUFFER_TRACE(bh, "get_write_access");
2247	retval = ext4_journal_get_write_access(handle, dir->i_sb, bh,
2248	EXT4_JTR_NONE);
2249	if (retval) {
2250	ext4_std_error(dir->i_sb, retval);
2251	brelse(bh);
2252	return retval;
2253	}
2254	root = (struct dx_root *) bh->b_data;
2255
2256	/* The 0th block becomes the root, move the dirents out */
2257	fde = &root->dotdot;
2258	de = (struct ext4_dir_entry_2 *)((char *)fde +
2259	ext4_rec_len_from_disk(dlen: fde->rec_len, blocksize));
2260	if ((char *) de >= (((char *) root) + blocksize)) {
2261	EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
2262	brelse(bh);
2263	return -EFSCORRUPTED;
2264	}
2265	len = ((char *) root) + (blocksize - csum_size) - (char *) de;
2266
2267	/* Allocate new block for the 0th block's dirents */
2268	bh2 = ext4_append(handle, inode: dir, block: &block);
2269	if (IS_ERR(ptr: bh2)) {
2270	brelse(bh);
2271	return PTR_ERR(ptr: bh2);
2272	}
2273	ext4_set_inode_flag(inode: dir, bit: EXT4_INODE_INDEX);
2274	data2 = bh2->b_data;
2275
2276	memcpy(data2, de, len);
2277	memset(de, 0, len); /* wipe old data */
2278	de = (struct ext4_dir_entry_2 *) data2;
2279	top = data2 + len;
2280	while ((char *)(de2 = ext4_next_entry(p: de, blocksize)) < top) {
2281	if (ext4_check_dir_entry(dir, NULL, de, bh2, data2, len,
2282	(char *)de - data2)) {
2283	brelse(bh: bh2);
2284	brelse(bh);
2285	return -EFSCORRUPTED;
2286	}
2287	de = de2;
2288	}
2289	de->rec_len = ext4_rec_len_to_disk(len: data2 + (blocksize - csum_size) -
2290	(char *) de, blocksize);
2291
2292	if (csum_size)
2293	ext4_initialize_dirent_tail(bh: bh2, blocksize);
2294
2295	/* Initialize the root; the dot dirents already exist */
2296	de = (struct ext4_dir_entry_2 *) (&root->dotdot);
2297	de->rec_len = ext4_rec_len_to_disk(
2298	len: blocksize - ext4_dir_rec_len(name_len: 2, NULL), blocksize);
2299	memset (&root->info, 0, sizeof(root->info));
2300	root->info.info_length = sizeof(root->info);
2301	if (ext4_hash_in_dirent(inode: dir))
2302	root->info.hash_version = DX_HASH_SIPHASH;
2303	else
2304	root->info.hash_version =
2305	EXT4_SB(sb: dir->i_sb)->s_def_hash_version;
2306
2307	entries = root->entries;
2308	dx_set_block(entry: entries, value: 1);
2309	dx_set_count(entries, value: 1);
2310	dx_set_limit(entries, value: dx_root_limit(dir, infosize: sizeof(root->info)));
2311
2312	/* Initialize as for dx_probe */
2313	fname->hinfo.hash_version = root->info.hash_version;
2314	if (fname->hinfo.hash_version <= DX_HASH_TEA)
2315	fname->hinfo.hash_version += EXT4_SB(sb: dir->i_sb)->s_hash_unsigned;
2316	fname->hinfo.seed = EXT4_SB(sb: dir->i_sb)->s_hash_seed;
2317
2318	/* casefolded encrypted hashes are computed on fname setup */
2319	if (!ext4_hash_in_dirent(inode: dir)) {
2320	int err = ext4fs_dirhash(dir, fname_name(fname),
2321	fname_len(fname), hinfo: &fname->hinfo);
2322	if (err < 0) {
2323	brelse(bh: bh2);
2324	brelse(bh);
2325	return err;
2326	}
2327	}
2328	memset(frames, 0, sizeof(frames));
2329	frame = frames;
2330	frame->entries = entries;
2331	frame->at = entries;
2332	frame->bh = bh;
2333
2334	retval = ext4_handle_dirty_dx_node(handle, inode: dir, bh: frame->bh);
2335	if (retval)
2336	goto out_frames;
2337	retval = ext4_handle_dirty_dirblock(handle, inode: dir, bh: bh2);
2338	if (retval)
2339	goto out_frames;
2340
2341	de = do_split(handle,dir, bh: &bh2, frame, hinfo: &fname->hinfo);
2342	if (IS_ERR(ptr: de)) {
2343	retval = PTR_ERR(ptr: de);
2344	goto out_frames;
2345	}
2346
2347	retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh: bh2);
2348	out_frames:
2349	/*
2350	* Even if the block split failed, we have to properly write
2351	* out all the changes we did so far. Otherwise we can end up
2352	* with corrupted filesystem.
2353	*/
2354	if (retval)
2355	ext4_mark_inode_dirty(handle, dir);
2356	dx_release(frames);
2357	brelse(bh: bh2);
2358	return retval;
2359	}
2360
2361	/*
2362	* ext4_add_entry()
2363	*
2364	* adds a file entry to the specified directory, using the same
2365	* semantics as ext4_find_entry(). It returns NULL if it failed.
2366	*
2367	* NOTE!! The inode part of 'de' is left at 0 - which means you
2368	* may not sleep between calling this and putting something into
2369	* the entry, as someone else might have used it while you slept.
2370	*/
2371	static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
2372	struct inode *inode)
2373	{
2374	struct inode *dir = d_inode(dentry: dentry->d_parent);
2375	struct buffer_head *bh = NULL;
2376	struct ext4_dir_entry_2 *de;
2377	struct super_block *sb;
2378	struct ext4_filename fname;
2379	int retval;
2380	int dx_fallback=0;
2381	unsigned blocksize;
2382	ext4_lblk_t block, blocks;
2383	int csum_size = 0;
2384
2385	if (ext4_has_metadata_csum(sb: inode->i_sb))
2386	csum_size = sizeof(struct ext4_dir_entry_tail);
2387
2388	sb = dir->i_sb;
2389	blocksize = sb->s_blocksize;
2390
2391	if (fscrypt_is_nokey_name(dentry))
2392	return -ENOKEY;
2393
2394	#if IS_ENABLED(CONFIG_UNICODE)
2395	if (sb_has_strict_encoding(sb) && IS_CASEFOLDED(dir) &&
2396	utf8_validate(um: sb->s_encoding, str: &dentry->d_name))
2397	return -EINVAL;
2398	#endif
2399
2400	retval = ext4_fname_setup_filename(dir, iname: &dentry->d_name, lookup: 0, fname: &fname);
2401	if (retval)
2402	return retval;
2403
2404	if (ext4_has_inline_data(inode: dir)) {
2405	retval = ext4_try_add_inline_entry(handle, fname: &fname, dir, inode);
2406	if (retval < 0)
2407	goto out;
2408	if (retval == 1) {
2409	retval = 0;
2410	goto out;
2411	}
2412	}
2413
2414	if (is_dx(dir)) {
2415	retval = ext4_dx_add_entry(handle, fname: &fname, dir, inode);
2416	if (!retval || (retval != ERR_BAD_DX_DIR))
2417	goto out;
2418	/* Can we just ignore htree data? */
2419	if (ext4_has_metadata_csum(sb)) {
2420	EXT4_ERROR_INODE(dir,
2421	"Directory has corrupted htree index.");
2422	retval = -EFSCORRUPTED;
2423	goto out;
2424	}
2425	ext4_clear_inode_flag(inode: dir, bit: EXT4_INODE_INDEX);
2426	dx_fallback++;
2427	retval = ext4_mark_inode_dirty(handle, dir);
2428	if (unlikely(retval))
2429	goto out;
2430	}
2431	blocks = dir->i_size >> sb->s_blocksize_bits;
2432	for (block = 0; block < blocks; block++) {
2433	bh = ext4_read_dirblock(dir, block, DIRENT);
2434	if (bh == NULL) {
2435	bh = ext4_bread(handle, dir, block,
2436	EXT4_GET_BLOCKS_CREATE);
2437	goto add_to_new_block;
2438	}
2439	if (IS_ERR(ptr: bh)) {
2440	retval = PTR_ERR(ptr: bh);
2441	bh = NULL;
2442	goto out;
2443	}
2444	retval = add_dirent_to_buf(handle, fname: &fname, dir, inode,
2445	NULL, bh);
2446	if (retval != -ENOSPC)
2447	goto out;
2448
2449	if (blocks == 1 && !dx_fallback &&
2450	ext4_has_feature_dir_index(sb)) {
2451	retval = make_indexed_dir(handle, fname: &fname, dir,
2452	inode, bh);
2453	bh = NULL; /* make_indexed_dir releases bh */
2454	goto out;
2455	}
2456	brelse(bh);
2457	}
2458	bh = ext4_append(handle, inode: dir, block: &block);
2459	add_to_new_block:
2460	if (IS_ERR(ptr: bh)) {
2461	retval = PTR_ERR(ptr: bh);
2462	bh = NULL;
2463	goto out;
2464	}
2465	de = (struct ext4_dir_entry_2 *) bh->b_data;
2466	de->inode = 0;
2467	de->rec_len = ext4_rec_len_to_disk(len: blocksize - csum_size, blocksize);
2468
2469	if (csum_size)
2470	ext4_initialize_dirent_tail(bh, blocksize);
2471
2472	retval = add_dirent_to_buf(handle, fname: &fname, dir, inode, de, bh);
2473	out:
2474	ext4_fname_free_filename(fname: &fname);
2475	brelse(bh);
2476	if (retval == 0)
2477	ext4_set_inode_state(inode, bit: EXT4_STATE_NEWENTRY);
2478	return retval;
2479	}
2480
2481	/*
2482	* Returns 0 for success, or a negative error value
2483	*/
2484	static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
2485	struct inode *dir, struct inode *inode)
2486	{
2487	struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
2488	struct dx_entry *entries, *at;
2489	struct buffer_head *bh;
2490	struct super_block *sb = dir->i_sb;
2491	struct ext4_dir_entry_2 *de;
2492	int restart;
2493	int err;
2494
2495	again:
2496	restart = 0;
2497	frame = dx_probe(fname, dir, NULL, frame_in: frames);
2498	if (IS_ERR(ptr: frame))
2499	return PTR_ERR(ptr: frame);
2500	entries = frame->entries;
2501	at = frame->at;
2502	bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT_HTREE);
2503	if (IS_ERR(ptr: bh)) {
2504	err = PTR_ERR(ptr: bh);
2505	bh = NULL;
2506	goto cleanup;
2507	}
2508
2509	BUFFER_TRACE(bh, "get_write_access");
2510	err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
2511	if (err)
2512	goto journal_error;
2513
2514	err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh);
2515	if (err != -ENOSPC)
2516	goto cleanup;
2517
2518	err = 0;
2519	/* Block full, should compress but for now just split */
2520	dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
2521	dx_get_count(entries), dx_get_limit(entries)));
2522	/* Need to split index? */
2523	if (dx_get_count(entries) == dx_get_limit(entries)) {
2524	ext4_lblk_t newblock;
2525	int levels = frame - frames + 1;
2526	unsigned int icount;
2527	int add_level = 1;
2528	struct dx_entry *entries2;
2529	struct dx_node *node2;
2530	struct buffer_head *bh2;
2531
2532	while (frame > frames) {
2533	if (dx_get_count(entries: (frame - 1)->entries) <
2534	dx_get_limit(entries: (frame - 1)->entries)) {
2535	add_level = 0;
2536	break;
2537	}
2538	frame--; /* split higher index block */
2539	at = frame->at;
2540	entries = frame->entries;
2541	restart = 1;
2542	}
2543	if (add_level && levels == ext4_dir_htree_level(sb)) {
2544	ext4_warning(sb, "Directory (ino: %lu) index full, "
2545	"reach max htree level :%d",
2546	dir->i_ino, levels);
2547	if (ext4_dir_htree_level(sb) < EXT4_HTREE_LEVEL) {
2548	ext4_warning(sb, "Large directory feature is "
2549	"not enabled on this "
2550	"filesystem");
2551	}
2552	err = -ENOSPC;
2553	goto cleanup;
2554	}
2555	icount = dx_get_count(entries);
2556	bh2 = ext4_append(handle, inode: dir, block: &newblock);
2557	if (IS_ERR(ptr: bh2)) {
2558	err = PTR_ERR(ptr: bh2);
2559	goto cleanup;
2560	}
2561	node2 = (struct dx_node *)(bh2->b_data);
2562	entries2 = node2->entries;
2563	memset(&node2->fake, 0, sizeof(struct fake_dirent));
2564	node2->fake.rec_len = ext4_rec_len_to_disk(len: sb->s_blocksize,
2565	blocksize: sb->s_blocksize);
2566	BUFFER_TRACE(frame->bh, "get_write_access");
2567	err = ext4_journal_get_write_access(handle, sb, frame->bh,
2568	EXT4_JTR_NONE);
2569	if (err)
2570	goto journal_error;
2571	if (!add_level) {
2572	unsigned icount1 = icount/2, icount2 = icount - icount1;
2573	unsigned hash2 = dx_get_hash(entry: entries + icount1);
2574	dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
2575	icount1, icount2));
2576
2577	BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
2578	err = ext4_journal_get_write_access(handle, sb,
2579	(frame - 1)->bh,
2580	EXT4_JTR_NONE);
2581	if (err)
2582	goto journal_error;
2583
2584	memcpy((char *) entries2, (char *) (entries + icount1),
2585	icount2 * sizeof(struct dx_entry));
2586	dx_set_count(entries, value: icount1);
2587	dx_set_count(entries: entries2, value: icount2);
2588	dx_set_limit(entries: entries2, value: dx_node_limit(dir));
2589
2590	/* Which index block gets the new entry? */
2591	if (at - entries >= icount1) {
2592	frame->at = at - entries - icount1 + entries2;
2593	frame->entries = entries = entries2;
2594	swap(frame->bh, bh2);
2595	}
2596	dx_insert_block(frame: (frame - 1), hash: hash2, block: newblock);
2597	dxtrace(dx_show_index("node", frame->entries));
2598	dxtrace(dx_show_index("node",
2599	((struct dx_node *) bh2->b_data)->entries));
2600	err = ext4_handle_dirty_dx_node(handle, inode: dir, bh: bh2);
2601	if (err)
2602	goto journal_error;
2603	brelse (bh: bh2);
2604	err = ext4_handle_dirty_dx_node(handle, inode: dir,
2605	bh: (frame - 1)->bh);
2606	if (err)
2607	goto journal_error;
2608	err = ext4_handle_dirty_dx_node(handle, inode: dir,
2609	bh: frame->bh);
2610	if (restart || err)
2611	goto journal_error;
2612	} else {
2613	struct dx_root *dxroot;
2614	memcpy((char *) entries2, (char *) entries,
2615	icount * sizeof(struct dx_entry));
2616	dx_set_limit(entries: entries2, value: dx_node_limit(dir));
2617
2618	/* Set up root */
2619	dx_set_count(entries, value: 1);
2620	dx_set_block(entry: entries + 0, value: newblock);
2621	dxroot = (struct dx_root *)frames[0].bh->b_data;
2622	dxroot->info.indirect_levels += 1;
2623	dxtrace(printk(KERN_DEBUG
2624	"Creating %d level index...\n",
2625	dxroot->info.indirect_levels));
2626	err = ext4_handle_dirty_dx_node(handle, inode: dir, bh: frame->bh);
2627	if (err)
2628	goto journal_error;
2629	err = ext4_handle_dirty_dx_node(handle, inode: dir, bh: bh2);
2630	brelse(bh: bh2);
2631	restart = 1;
2632	goto journal_error;
2633	}
2634	}
2635	de = do_split(handle, dir, bh: &bh, frame, hinfo: &fname->hinfo);
2636	if (IS_ERR(ptr: de)) {
2637	err = PTR_ERR(ptr: de);
2638	goto cleanup;
2639	}
2640	err = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
2641	goto cleanup;
2642
2643	journal_error:
2644	ext4_std_error(dir->i_sb, err); /* this is a no-op if err == 0 */
2645	cleanup:
2646	brelse(bh);
2647	dx_release(frames);
2648	/* @restart is true means htree-path has been changed, we need to
2649	* repeat dx_probe() to find out valid htree-path
2650	*/
2651	if (restart && err == 0)
2652	goto again;
2653	return err;
2654	}
2655
2656	/*
2657	* ext4_generic_delete_entry deletes a directory entry by merging it
2658	* with the previous entry
2659	*/
2660	int ext4_generic_delete_entry(struct inode *dir,
2661	struct ext4_dir_entry_2 *de_del,
2662	struct buffer_head *bh,
2663	void *entry_buf,
2664	int buf_size,
2665	int csum_size)
2666	{
2667	struct ext4_dir_entry_2 *de, *pde;
2668	unsigned int blocksize = dir->i_sb->s_blocksize;
2669	int i;
2670
2671	i = 0;
2672	pde = NULL;
2673	de = entry_buf;
2674	while (i < buf_size - csum_size) {
2675	if (ext4_check_dir_entry(dir, NULL, de, bh,
2676	entry_buf, buf_size, i))
2677	return -EFSCORRUPTED;
2678	if (de == de_del) {
2679	if (pde) {
2680	pde->rec_len = ext4_rec_len_to_disk(
2681	len: ext4_rec_len_from_disk(dlen: pde->rec_len,
2682	blocksize) +
2683	ext4_rec_len_from_disk(dlen: de->rec_len,
2684	blocksize),
2685	blocksize);
2686
2687	/* wipe entire dir_entry */
2688	memset(de, 0, ext4_rec_len_from_disk(de->rec_len,
2689	blocksize));
2690	} else {
2691	/* wipe dir_entry excluding the rec_len field */
2692	de->inode = 0;
2693	memset(&de->name_len, 0,
2694	ext4_rec_len_from_disk(de->rec_len,
2695	blocksize) -
2696	offsetof(struct ext4_dir_entry_2,
2697	name_len));
2698	}
2699
2700	inode_inc_iversion(inode: dir);
2701	return 0;
2702	}
2703	i += ext4_rec_len_from_disk(dlen: de->rec_len, blocksize);
2704	pde = de;
2705	de = ext4_next_entry(p: de, blocksize);
2706	}
2707	return -ENOENT;
2708	}
2709
2710	static int ext4_delete_entry(handle_t *handle,
2711	struct inode *dir,
2712	struct ext4_dir_entry_2 *de_del,
2713	struct buffer_head *bh)
2714	{
2715	int err, csum_size = 0;
2716
2717	if (ext4_has_inline_data(inode: dir)) {
2718	int has_inline_data = 1;
2719	err = ext4_delete_inline_entry(handle, dir, de_del, bh,
2720	has_inline_data: &has_inline_data);
2721	if (has_inline_data)
2722	return err;
2723	}
2724
2725	if (ext4_has_metadata_csum(sb: dir->i_sb))
2726	csum_size = sizeof(struct ext4_dir_entry_tail);
2727
2728	BUFFER_TRACE(bh, "get_write_access");
2729	err = ext4_journal_get_write_access(handle, dir->i_sb, bh,
2730	EXT4_JTR_NONE);
2731	if (unlikely(err))
2732	goto out;
2733
2734	err = ext4_generic_delete_entry(dir, de_del, bh, entry_buf: bh->b_data,
2735	buf_size: dir->i_sb->s_blocksize, csum_size);
2736	if (err)
2737	goto out;
2738
2739	BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
2740	err = ext4_handle_dirty_dirblock(handle, inode: dir, bh);
2741	if (unlikely(err))
2742	goto out;
2743
2744	return 0;
2745	out:
2746	if (err != -ENOENT)
2747	ext4_std_error(dir->i_sb, err);
2748	return err;
2749	}
2750
2751	/*
2752	* Set directory link count to 1 if nlinks > EXT4_LINK_MAX, or if nlinks == 2
2753	* since this indicates that nlinks count was previously 1 to avoid overflowing
2754	* the 16-bit i_links_count field on disk. Directories with i_nlink == 1 mean
2755	* that subdirectory link counts are not being maintained accurately.
2756	*
2757	* The caller has already checked for i_nlink overflow in case the DIR_LINK
2758	* feature is not enabled and returned -EMLINK. The is_dx() check is a proxy
2759	* for checking S_ISDIR(inode) (since the INODE_INDEX feature will not be set
2760	* on regular files) and to avoid creating huge/slow non-HTREE directories.
2761	*/
2762	static void ext4_inc_count(struct inode *inode)
2763	{
2764	inc_nlink(inode);
2765	if (is_dx(inode) &&
2766	(inode->i_nlink > EXT4_LINK_MAX || inode->i_nlink == 2))
2767	set_nlink(inode, nlink: 1);
2768	}
2769
2770	/*
2771	* If a directory had nlink == 1, then we should let it be 1. This indicates
2772	* directory has >EXT4_LINK_MAX subdirs.
2773	*/
2774	static void ext4_dec_count(struct inode *inode)
2775	{
2776	if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
2777	drop_nlink(inode);
2778	}
2779
2780
2781	/*
2782	* Add non-directory inode to a directory. On success, the inode reference is
2783	* consumed by dentry is instantiation. This is also indicated by clearing of
2784	* *inodep pointer. On failure, the caller is responsible for dropping the
2785	* inode reference in the safe context.
2786	*/
2787	static int ext4_add_nondir(handle_t *handle,
2788	struct dentry *dentry, struct inode **inodep)
2789	{
2790	struct inode *dir = d_inode(dentry: dentry->d_parent);
2791	struct inode *inode = *inodep;
2792	int err = ext4_add_entry(handle, dentry, inode);
2793	if (!err) {
2794	err = ext4_mark_inode_dirty(handle, inode);
2795	if (IS_DIRSYNC(dir))
2796	ext4_handle_sync(handle);
2797	d_instantiate_new(dentry, inode);
2798	*inodep = NULL;
2799	return err;
2800	}
2801	drop_nlink(inode);
2802	ext4_mark_inode_dirty(handle, inode);
2803	ext4_orphan_add(handle, inode);
2804	unlock_new_inode(inode);
2805	return err;
2806	}
2807
2808	/*
2809	* By the time this is called, we already have created
2810	* the directory cache entry for the new file, but it
2811	* is so far negative - it has no inode.
2812	*
2813	* If the create succeeds, we fill in the inode information
2814	* with d_instantiate().
2815	*/
2816	static int ext4_create(struct mnt_idmap *idmap, struct inode *dir,
2817	struct dentry *dentry, umode_t mode, bool excl)
2818	{
2819	handle_t *handle;
2820	struct inode *inode;
2821	int err, credits, retries = 0;
2822
2823	err = dquot_initialize(inode: dir);
2824	if (err)
2825	return err;
2826
2827	credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2828	EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2829	retry:
2830	inode = ext4_new_inode_start_handle(idmap, dir, mode, &dentry->d_name,
2831	0, NULL, EXT4_HT_DIR, credits);
2832	handle = ext4_journal_current_handle();
2833	err = PTR_ERR(ptr: inode);
2834	if (!IS_ERR(ptr: inode)) {
2835	inode->i_op = &ext4_file_inode_operations;
2836	inode->i_fop = &ext4_file_operations;
2837	ext4_set_aops(inode);
2838	err = ext4_add_nondir(handle, dentry, inodep: &inode);
2839	if (!err)
2840	ext4_fc_track_create(handle, dentry);
2841	}
2842	if (handle)
2843	ext4_journal_stop(handle);
2844	if (!IS_ERR_OR_NULL(ptr: inode))
2845	iput(inode);
2846	if (err == -ENOSPC && ext4_should_retry_alloc(sb: dir->i_sb, retries: &retries))
2847	goto retry;
2848	return err;
2849	}
2850
2851	static int ext4_mknod(struct mnt_idmap *idmap, struct inode *dir,
2852	struct dentry *dentry, umode_t mode, dev_t rdev)
2853	{
2854	handle_t *handle;
2855	struct inode *inode;
2856	int err, credits, retries = 0;
2857
2858	err = dquot_initialize(inode: dir);
2859	if (err)
2860	return err;
2861
2862	credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2863	EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
2864	retry:
2865	inode = ext4_new_inode_start_handle(idmap, dir, mode, &dentry->d_name,
2866	0, NULL, EXT4_HT_DIR, credits);
2867	handle = ext4_journal_current_handle();
2868	err = PTR_ERR(ptr: inode);
2869	if (!IS_ERR(ptr: inode)) {
2870	init_special_inode(inode, inode->i_mode, rdev);
2871	inode->i_op = &ext4_special_inode_operations;
2872	err = ext4_add_nondir(handle, dentry, inodep: &inode);
2873	if (!err)
2874	ext4_fc_track_create(handle, dentry);
2875	}
2876	if (handle)
2877	ext4_journal_stop(handle);
2878	if (!IS_ERR_OR_NULL(ptr: inode))
2879	iput(inode);
2880	if (err == -ENOSPC && ext4_should_retry_alloc(sb: dir->i_sb, retries: &retries))
2881	goto retry;
2882	return err;
2883	}
2884
2885	static int ext4_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
2886	struct file *file, umode_t mode)
2887	{
2888	handle_t *handle;
2889	struct inode *inode;
2890	int err, retries = 0;
2891
2892	err = dquot_initialize(inode: dir);
2893	if (err)
2894	return err;
2895
2896	retry:
2897	inode = ext4_new_inode_start_handle(idmap, dir, mode,
2898	NULL, 0, NULL,
2899	EXT4_HT_DIR,
2900	EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
2901	4 + EXT4_XATTR_TRANS_BLOCKS);
2902	handle = ext4_journal_current_handle();
2903	err = PTR_ERR(ptr: inode);
2904	if (!IS_ERR(ptr: inode)) {
2905	inode->i_op = &ext4_file_inode_operations;
2906	inode->i_fop = &ext4_file_operations;
2907	ext4_set_aops(inode);
2908	d_tmpfile(file, inode);
2909	err = ext4_orphan_add(handle, inode);
2910	if (err)
2911	goto err_unlock_inode;
2912	mark_inode_dirty(inode);
2913	unlock_new_inode(inode);
2914	}
2915	if (handle)
2916	ext4_journal_stop(handle);
2917	if (err == -ENOSPC && ext4_should_retry_alloc(sb: dir->i_sb, retries: &retries))
2918	goto retry;
2919	return finish_open_simple(file, error: err);
2920	err_unlock_inode:
2921	ext4_journal_stop(handle);
2922	unlock_new_inode(inode);
2923	return err;
2924	}
2925
2926	struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
2927	struct ext4_dir_entry_2 *de,
2928	int blocksize, int csum_size,
2929	unsigned int parent_ino, int dotdot_real_len)
2930	{
2931	de->inode = cpu_to_le32(inode->i_ino);
2932	de->name_len = 1;
2933	de->rec_len = ext4_rec_len_to_disk(len: ext4_dir_rec_len(name_len: de->name_len, NULL),
2934	blocksize);
2935	strcpy(p: de->name, q: ".");
2936	ext4_set_de_type(sb: inode->i_sb, de, S_IFDIR);
2937
2938	de = ext4_next_entry(p: de, blocksize);
2939	de->inode = cpu_to_le32(parent_ino);
2940	de->name_len = 2;
2941	if (!dotdot_real_len)
2942	de->rec_len = ext4_rec_len_to_disk(len: blocksize -
2943	(csum_size + ext4_dir_rec_len(name_len: 1, NULL)),
2944	blocksize);
2945	else
2946	de->rec_len = ext4_rec_len_to_disk(
2947	len: ext4_dir_rec_len(name_len: de->name_len, NULL),
2948	blocksize);
2949	strcpy(p: de->name, q: "..");
2950	ext4_set_de_type(sb: inode->i_sb, de, S_IFDIR);
2951
2952	return ext4_next_entry(p: de, blocksize);
2953	}
2954
2955	int ext4_init_new_dir(handle_t *handle, struct inode *dir,
2956	struct inode *inode)
2957	{
2958	struct buffer_head *dir_block = NULL;
2959	struct ext4_dir_entry_2 *de;
2960	ext4_lblk_t block = 0;
2961	unsigned int blocksize = dir->i_sb->s_blocksize;
2962	int csum_size = 0;
2963	int err;
2964
2965	if (ext4_has_metadata_csum(sb: dir->i_sb))
2966	csum_size = sizeof(struct ext4_dir_entry_tail);
2967
2968	if (ext4_test_inode_state(inode, bit: EXT4_STATE_MAY_INLINE_DATA)) {
2969	err = ext4_try_create_inline_dir(handle, parent: dir, inode);
2970	if (err < 0 && err != -ENOSPC)
2971	goto out;
2972	if (!err)
2973	goto out;
2974	}
2975
2976	inode->i_size = 0;
2977	dir_block = ext4_append(handle, inode, block: &block);
2978	if (IS_ERR(ptr: dir_block))
2979	return PTR_ERR(ptr: dir_block);
2980	de = (struct ext4_dir_entry_2 *)dir_block->b_data;
2981	ext4_init_dot_dotdot(inode, de, blocksize, csum_size, parent_ino: dir->i_ino, dotdot_real_len: 0);
2982	set_nlink(inode, nlink: 2);
2983	if (csum_size)
2984	ext4_initialize_dirent_tail(bh: dir_block, blocksize);
2985
2986	BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
2987	err = ext4_handle_dirty_dirblock(handle, inode, bh: dir_block);
2988	if (err)
2989	goto out;
2990	set_buffer_verified(dir_block);
2991	out:
2992	brelse(bh: dir_block);
2993	return err;
2994	}
2995
2996	static int ext4_mkdir(struct mnt_idmap *idmap, struct inode *dir,
2997	struct dentry *dentry, umode_t mode)
2998	{
2999	handle_t *handle;
3000	struct inode *inode;
3001	int err, err2 = 0, credits, retries = 0;
3002
3003	if (EXT4_DIR_LINK_MAX(dir))
3004	return -EMLINK;
3005
3006	err = dquot_initialize(inode: dir);
3007	if (err)
3008	return err;
3009
3010	credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3011	EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
3012	retry:
3013	inode = ext4_new_inode_start_handle(idmap, dir, S_IFDIR | mode,
3014	&dentry->d_name,
3015	0, NULL, EXT4_HT_DIR, credits);
3016	handle = ext4_journal_current_handle();
3017	err = PTR_ERR(ptr: inode);
3018	if (IS_ERR(ptr: inode))
3019	goto out_stop;
3020
3021	inode->i_op = &ext4_dir_inode_operations;
3022	inode->i_fop = &ext4_dir_operations;
3023	err = ext4_init_new_dir(handle, dir, inode);
3024	if (err)
3025	goto out_clear_inode;
3026	err = ext4_mark_inode_dirty(handle, inode);
3027	if (!err)
3028	err = ext4_add_entry(handle, dentry, inode);
3029	if (err) {
3030	out_clear_inode:
3031	clear_nlink(inode);
3032	ext4_orphan_add(handle, inode);
3033	unlock_new_inode(inode);
3034	err2 = ext4_mark_inode_dirty(handle, inode);
3035	if (unlikely(err2))
3036	err = err2;
3037	ext4_journal_stop(handle);
3038	iput(inode);
3039	goto out_retry;
3040	}
3041	ext4_inc_count(inode: dir);
3042
3043	ext4_update_dx_flag(inode: dir);
3044	err = ext4_mark_inode_dirty(handle, dir);
3045	if (err)
3046	goto out_clear_inode;
3047	d_instantiate_new(dentry, inode);
3048	ext4_fc_track_create(handle, dentry);
3049	if (IS_DIRSYNC(dir))
3050	ext4_handle_sync(handle);
3051
3052	out_stop:
3053	if (handle)
3054	ext4_journal_stop(handle);
3055	out_retry:
3056	if (err == -ENOSPC && ext4_should_retry_alloc(sb: dir->i_sb, retries: &retries))
3057	goto retry;
3058	return err;
3059	}
3060
3061	/*
3062	* routine to check that the specified directory is empty (for rmdir)
3063	*/
3064	bool ext4_empty_dir(struct inode *inode)
3065	{
3066	unsigned int offset;
3067	struct buffer_head *bh;
3068	struct ext4_dir_entry_2 *de;
3069	struct super_block *sb;
3070
3071	if (ext4_has_inline_data(inode)) {
3072	int has_inline_data = 1;
3073	int ret;
3074
3075	ret = empty_inline_dir(dir: inode, has_inline_data: &has_inline_data);
3076	if (has_inline_data)
3077	return ret;
3078	}
3079
3080	sb = inode->i_sb;
3081	if (inode->i_size < ext4_dir_rec_len(name_len: 1, NULL) +
3082	ext4_dir_rec_len(name_len: 2, NULL)) {
3083	EXT4_ERROR_INODE(inode, "invalid size");
3084	return false;
3085	}
3086	/* The first directory block must not be a hole,
3087	* so treat it as DIRENT_HTREE
3088	*/
3089	bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE);
3090	if (IS_ERR(ptr: bh))
3091	return false;
3092
3093	de = (struct ext4_dir_entry_2 *) bh->b_data;
3094	if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size,
3095	0) ||
3096	le32_to_cpu(de->inode) != inode->i_ino || strcmp(".", de->name)) {
3097	ext4_warning_inode(inode, "directory missing '.'");
3098	brelse(bh);
3099	return false;
3100	}
3101	offset = ext4_rec_len_from_disk(dlen: de->rec_len, blocksize: sb->s_blocksize);
3102	de = ext4_next_entry(p: de, blocksize: sb->s_blocksize);
3103	if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size,
3104	offset) ||
3105	le32_to_cpu(de->inode) == 0 || strcmp("..", de->name)) {
3106	ext4_warning_inode(inode, "directory missing '..'");
3107	brelse(bh);
3108	return false;
3109	}
3110	offset += ext4_rec_len_from_disk(dlen: de->rec_len, blocksize: sb->s_blocksize);
3111	while (offset < inode->i_size) {
3112	if (!(offset & (sb->s_blocksize - 1))) {
3113	unsigned int lblock;
3114	brelse(bh);
3115	lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
3116	bh = ext4_read_dirblock(inode, lblock, EITHER);
3117	if (bh == NULL) {
3118	offset += sb->s_blocksize;
3119	continue;
3120	}
3121	if (IS_ERR(ptr: bh))
3122	return false;
3123	}
3124	de = (struct ext4_dir_entry_2 *) (bh->b_data +
3125	(offset & (sb->s_blocksize - 1)));
3126	if (ext4_check_dir_entry(inode, NULL, de, bh,
3127	bh->b_data, bh->b_size, offset) ||
3128	le32_to_cpu(de->inode)) {
3129	brelse(bh);
3130	return false;
3131	}
3132	offset += ext4_rec_len_from_disk(dlen: de->rec_len, blocksize: sb->s_blocksize);
3133	}
3134	brelse(bh);
3135	return true;
3136	}
3137
3138	static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
3139	{
3140	int retval;
3141	struct inode *inode;
3142	struct buffer_head *bh;
3143	struct ext4_dir_entry_2 *de;
3144	handle_t *handle = NULL;
3145
3146	if (unlikely(ext4_forced_shutdown(dir->i_sb)))
3147	return -EIO;
3148
3149	/* Initialize quotas before so that eventual writes go in
3150	* separate transaction */
3151	retval = dquot_initialize(inode: dir);
3152	if (retval)
3153	return retval;
3154	retval = dquot_initialize(inode: d_inode(dentry));
3155	if (retval)
3156	return retval;
3157
3158	retval = -ENOENT;
3159	bh = ext4_find_entry(dir, d_name: &dentry->d_name, res_dir: &de, NULL);
3160	if (IS_ERR(ptr: bh))
3161	return PTR_ERR(ptr: bh);
3162	if (!bh)
3163	goto end_rmdir;
3164
3165	inode = d_inode(dentry);
3166
3167	retval = -EFSCORRUPTED;
3168	if (le32_to_cpu(de->inode) != inode->i_ino)
3169	goto end_rmdir;
3170
3171	retval = -ENOTEMPTY;
3172	if (!ext4_empty_dir(inode))
3173	goto end_rmdir;
3174
3175	handle = ext4_journal_start(dir, EXT4_HT_DIR,
3176	EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3177	if (IS_ERR(ptr: handle)) {
3178	retval = PTR_ERR(ptr: handle);
3179	handle = NULL;
3180	goto end_rmdir;
3181	}
3182
3183	if (IS_DIRSYNC(dir))
3184	ext4_handle_sync(handle);
3185
3186	retval = ext4_delete_entry(handle, dir, de_del: de, bh);
3187	if (retval)
3188	goto end_rmdir;
3189	if (!EXT4_DIR_LINK_EMPTY(inode))
3190	ext4_warning_inode(inode,
3191	"empty directory '%.*s' has too many links (%u)",
3192	dentry->d_name.len, dentry->d_name.name,
3193	inode->i_nlink);
3194	inode_inc_iversion(inode);
3195	clear_nlink(inode);
3196	/* There's no need to set i_disksize: the fact that i_nlink is
3197	* zero will ensure that the right thing happens during any
3198	* recovery. */
3199	inode->i_size = 0;
3200	ext4_orphan_add(handle, inode);
3201	inode_set_mtime_to_ts(inode: dir, ts: inode_set_ctime_current(inode: dir));
3202	inode_set_ctime_current(inode);
3203	retval = ext4_mark_inode_dirty(handle, inode);
3204	if (retval)
3205	goto end_rmdir;
3206	ext4_dec_count(inode: dir);
3207	ext4_update_dx_flag(inode: dir);
3208	ext4_fc_track_unlink(handle, dentry);
3209	retval = ext4_mark_inode_dirty(handle, dir);
3210
3211	#if IS_ENABLED(CONFIG_UNICODE)
3212	/* VFS negative dentries are incompatible with Encoding and
3213	* Case-insensitiveness. Eventually we'll want avoid
3214	* invalidating the dentries here, alongside with returning the
3215	* negative dentries at ext4_lookup(), when it is better
3216	* supported by the VFS for the CI case.
3217	*/
3218	if (IS_CASEFOLDED(dir))
3219	d_invalidate(dentry);
3220	#endif
3221
3222	end_rmdir:
3223	brelse(bh);
3224	if (handle)
3225	ext4_journal_stop(handle);
3226	return retval;
3227	}
3228
3229	int __ext4_unlink(struct inode *dir, const struct qstr *d_name,
3230	struct inode *inode,
3231	struct dentry *dentry /* NULL during fast_commit recovery */)
3232	{
3233	int retval = -ENOENT;
3234	struct buffer_head *bh;
3235	struct ext4_dir_entry_2 *de;
3236	handle_t *handle;
3237	int skip_remove_dentry = 0;
3238
3239	/*
3240	* Keep this outside the transaction; it may have to set up the
3241	* directory's encryption key, which isn't GFP_NOFS-safe.
3242	*/
3243	bh = ext4_find_entry(dir, d_name, res_dir: &de, NULL);
3244	if (IS_ERR(ptr: bh))
3245	return PTR_ERR(ptr: bh);
3246
3247	if (!bh)
3248	return -ENOENT;
3249
3250	if (le32_to_cpu(de->inode) != inode->i_ino) {
3251	/*
3252	* It's okay if we find dont find dentry which matches
3253	* the inode. That's because it might have gotten
3254	* renamed to a different inode number
3255	*/
3256	if (EXT4_SB(sb: inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
3257	skip_remove_dentry = 1;
3258	else
3259	goto out_bh;
3260	}
3261
3262	handle = ext4_journal_start(dir, EXT4_HT_DIR,
3263	EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
3264	if (IS_ERR(ptr: handle)) {
3265	retval = PTR_ERR(ptr: handle);
3266	goto out_bh;
3267	}
3268
3269	if (IS_DIRSYNC(dir))
3270	ext4_handle_sync(handle);
3271
3272	if (!skip_remove_dentry) {
3273	retval = ext4_delete_entry(handle, dir, de_del: de, bh);
3274	if (retval)
3275	goto out_handle;
3276	inode_set_mtime_to_ts(inode: dir, ts: inode_set_ctime_current(inode: dir));
3277	ext4_update_dx_flag(inode: dir);
3278	retval = ext4_mark_inode_dirty(handle, dir);
3279	if (retval)
3280	goto out_handle;
3281	} else {
3282	retval = 0;
3283	}
3284	if (inode->i_nlink == 0)
3285	ext4_warning_inode(inode, "Deleting file '%.*s' with no links",
3286	d_name->len, d_name->name);
3287	else
3288	drop_nlink(inode);
3289	if (!inode->i_nlink)
3290	ext4_orphan_add(handle, inode);
3291	inode_set_ctime_current(inode);
3292	retval = ext4_mark_inode_dirty(handle, inode);
3293	if (dentry && !retval)
3294	ext4_fc_track_unlink(handle, dentry);
3295	out_handle:
3296	ext4_journal_stop(handle);
3297	out_bh:
3298	brelse(bh);
3299	return retval;
3300	}
3301
3302	static int ext4_unlink(struct inode *dir, struct dentry *dentry)
3303	{
3304	int retval;
3305
3306	if (unlikely(ext4_forced_shutdown(dir->i_sb)))
3307	return -EIO;
3308
3309	trace_ext4_unlink_enter(parent: dir, dentry);
3310	/*
3311	* Initialize quotas before so that eventual writes go
3312	* in separate transaction
3313	*/
3314	retval = dquot_initialize(inode: dir);
3315	if (retval)
3316	goto out_trace;
3317	retval = dquot_initialize(inode: d_inode(dentry));
3318	if (retval)
3319	goto out_trace;
3320
3321	retval = __ext4_unlink(dir, d_name: &dentry->d_name, inode: d_inode(dentry), dentry);
3322	#if IS_ENABLED(CONFIG_UNICODE)
3323	/* VFS negative dentries are incompatible with Encoding and
3324	* Case-insensitiveness. Eventually we'll want avoid
3325	* invalidating the dentries here, alongside with returning the
3326	* negative dentries at ext4_lookup(), when it is better
3327	* supported by the VFS for the CI case.
3328	*/
3329	if (IS_CASEFOLDED(dir))
3330	d_invalidate(dentry);
3331	#endif
3332
3333	out_trace:
3334	trace_ext4_unlink_exit(dentry, ret: retval);
3335	return retval;
3336	}
3337
3338	static int ext4_init_symlink_block(handle_t *handle, struct inode *inode,
3339	struct fscrypt_str *disk_link)
3340	{
3341	struct buffer_head *bh;
3342	char *kaddr;
3343	int err = 0;
3344
3345	bh = ext4_bread(handle, inode, 0, EXT4_GET_BLOCKS_CREATE);
3346	if (IS_ERR(ptr: bh))
3347	return PTR_ERR(ptr: bh);
3348
3349	BUFFER_TRACE(bh, "get_write_access");
3350	err = ext4_journal_get_write_access(handle, inode->i_sb, bh, EXT4_JTR_NONE);
3351	if (err)
3352	goto out;
3353
3354	kaddr = (char *)bh->b_data;
3355	memcpy(kaddr, disk_link->name, disk_link->len);
3356	inode->i_size = disk_link->len - 1;
3357	EXT4_I(inode)->i_disksize = inode->i_size;
3358	err = ext4_handle_dirty_metadata(handle, inode, bh);
3359	out:
3360	brelse(bh);
3361	return err;
3362	}
3363
3364	static int ext4_symlink(struct mnt_idmap *idmap, struct inode *dir,
3365	struct dentry *dentry, const char *symname)
3366	{
3367	handle_t *handle;
3368	struct inode *inode;
3369	int err, len = strlen(symname);
3370	int credits;
3371	struct fscrypt_str disk_link;
3372	int retries = 0;
3373
3374	if (unlikely(ext4_forced_shutdown(dir->i_sb)))
3375	return -EIO;
3376
3377	err = fscrypt_prepare_symlink(dir, target: symname, len, max_len: dir->i_sb->s_blocksize,
3378	disk_link: &disk_link);
3379	if (err)
3380	return err;
3381
3382	err = dquot_initialize(inode: dir);
3383	if (err)
3384	return err;
3385
3386	/*
3387	* EXT4_INDEX_EXTRA_TRANS_BLOCKS for addition of entry into the
3388	* directory. +3 for inode, inode bitmap, group descriptor allocation.
3389	* EXT4_DATA_TRANS_BLOCKS for the data block allocation and
3390	* modification.
3391	*/
3392	credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3393	EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
3394	retry:
3395	inode = ext4_new_inode_start_handle(idmap, dir, S_IFLNK|S_IRWXUGO,
3396	&dentry->d_name, 0, NULL,
3397	EXT4_HT_DIR, credits);
3398	handle = ext4_journal_current_handle();
3399	if (IS_ERR(ptr: inode)) {
3400	if (handle)
3401	ext4_journal_stop(handle);
3402	err = PTR_ERR(ptr: inode);
3403	goto out_retry;
3404	}
3405
3406	if (IS_ENCRYPTED(inode)) {
3407	err = fscrypt_encrypt_symlink(inode, target: symname, len, disk_link: &disk_link);
3408	if (err)
3409	goto err_drop_inode;
3410	inode->i_op = &ext4_encrypted_symlink_inode_operations;
3411	} else {
3412	if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3413	inode->i_op = &ext4_symlink_inode_operations;
3414	} else {
3415	inode->i_op = &ext4_fast_symlink_inode_operations;
3416	inode->i_link = (char *)&EXT4_I(inode)->i_data;
3417	}
3418	}
3419
3420	if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
3421	/* alloc symlink block and fill it */
3422	err = ext4_init_symlink_block(handle, inode, disk_link: &disk_link);
3423	if (err)
3424	goto err_drop_inode;
3425	} else {
3426	/* clear the extent format for fast symlink */
3427	ext4_clear_inode_flag(inode, bit: EXT4_INODE_EXTENTS);
3428	memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name,
3429	disk_link.len);
3430	inode->i_size = disk_link.len - 1;
3431	EXT4_I(inode)->i_disksize = inode->i_size;
3432	}
3433	err = ext4_add_nondir(handle, dentry, inodep: &inode);
3434	if (handle)
3435	ext4_journal_stop(handle);
3436	iput(inode);
3437	goto out_retry;
3438
3439	err_drop_inode:
3440	clear_nlink(inode);
3441	ext4_mark_inode_dirty(handle, inode);
3442	ext4_orphan_add(handle, inode);
3443	unlock_new_inode(inode);
3444	if (handle)
3445	ext4_journal_stop(handle);
3446	iput(inode);
3447	out_retry:
3448	if (err == -ENOSPC && ext4_should_retry_alloc(sb: dir->i_sb, retries: &retries))
3449	goto retry;
3450	if (disk_link.name != (unsigned char *)symname)
3451	kfree(objp: disk_link.name);
3452	return err;
3453	}
3454
3455	int __ext4_link(struct inode *dir, struct inode *inode, struct dentry *dentry)
3456	{
3457	handle_t *handle;
3458	int err, retries = 0;
3459	retry:
3460	handle = ext4_journal_start(dir, EXT4_HT_DIR,
3461	(EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
3462	EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1);
3463	if (IS_ERR(ptr: handle))
3464	return PTR_ERR(ptr: handle);
3465
3466	if (IS_DIRSYNC(dir))
3467	ext4_handle_sync(handle);
3468
3469	inode_set_ctime_current(inode);
3470	ext4_inc_count(inode);
3471	ihold(inode);
3472
3473	err = ext4_add_entry(handle, dentry, inode);
3474	if (!err) {
3475	err = ext4_mark_inode_dirty(handle, inode);
3476	/* this can happen only for tmpfile being
3477	* linked the first time
3478	*/
3479	if (inode->i_nlink == 1)
3480	ext4_orphan_del(handle, inode);
3481	d_instantiate(dentry, inode);
3482	ext4_fc_track_link(handle, dentry);
3483	} else {
3484	drop_nlink(inode);
3485	iput(inode);
3486	}
3487	ext4_journal_stop(handle);
3488	if (err == -ENOSPC && ext4_should_retry_alloc(sb: dir->i_sb, retries: &retries))
3489	goto retry;
3490	return err;
3491	}
3492
3493	static int ext4_link(struct dentry *old_dentry,
3494	struct inode *dir, struct dentry *dentry)
3495	{
3496	struct inode *inode = d_inode(dentry: old_dentry);
3497	int err;
3498
3499	if (inode->i_nlink >= EXT4_LINK_MAX)
3500	return -EMLINK;
3501
3502	err = fscrypt_prepare_link(old_dentry, dir, dentry);
3503	if (err)
3504	return err;
3505
3506	if ((ext4_test_inode_flag(inode: dir, bit: EXT4_INODE_PROJINHERIT)) &&
3507	(!projid_eq(EXT4_I(dir)->i_projid,
3508	EXT4_I(old_dentry->d_inode)->i_projid)))
3509	return -EXDEV;
3510
3511	err = dquot_initialize(inode: dir);
3512	if (err)
3513	return err;
3514	return __ext4_link(dir, inode, dentry);
3515	}
3516
3517	/*
3518	* Try to find buffer head where contains the parent block.
3519	* It should be the inode block if it is inlined or the 1st block
3520	* if it is a normal dir.
3521	*/
3522	static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
3523	struct inode *inode,
3524	int *retval,
3525	struct ext4_dir_entry_2 **parent_de,
3526	int *inlined)
3527	{
3528	struct buffer_head *bh;
3529
3530	if (!ext4_has_inline_data(inode)) {
3531	struct ext4_dir_entry_2 *de;
3532	unsigned int offset;
3533
3534	/* The first directory block must not be a hole, so
3535	* treat it as DIRENT_HTREE
3536	*/
3537	bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE);
3538	if (IS_ERR(ptr: bh)) {
3539	*retval = PTR_ERR(ptr: bh);
3540	return NULL;
3541	}
3542
3543	de = (struct ext4_dir_entry_2 *) bh->b_data;
3544	if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data,
3545	bh->b_size, 0) ||
3546	le32_to_cpu(de->inode) != inode->i_ino ||
3547	strcmp(".", de->name)) {
3548	EXT4_ERROR_INODE(inode, "directory missing '.'");
3549	brelse(bh);
3550	*retval = -EFSCORRUPTED;
3551	return NULL;
3552	}
3553	offset = ext4_rec_len_from_disk(dlen: de->rec_len,
3554	blocksize: inode->i_sb->s_blocksize);
3555	de = ext4_next_entry(p: de, blocksize: inode->i_sb->s_blocksize);
3556	if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data,
3557	bh->b_size, offset) ||
3558	le32_to_cpu(de->inode) == 0 || strcmp("..", de->name)) {
3559	EXT4_ERROR_INODE(inode, "directory missing '..'");
3560	brelse(bh);
3561	*retval = -EFSCORRUPTED;
3562	return NULL;
3563	}
3564	*parent_de = de;
3565
3566	return bh;
3567	}
3568
3569	*inlined = 1;
3570	return ext4_get_first_inline_block(inode, parent_de, retval);
3571	}
3572
3573	struct ext4_renament {
3574	struct inode *dir;
3575	struct dentry *dentry;
3576	struct inode *inode;
3577	bool is_dir;
3578	int dir_nlink_delta;
3579
3580	/* entry for "dentry" */
3581	struct buffer_head *bh;
3582	struct ext4_dir_entry_2 *de;
3583	int inlined;
3584
3585	/* entry for ".." in inode if it's a directory */
3586	struct buffer_head *dir_bh;
3587	struct ext4_dir_entry_2 *parent_de;
3588	int dir_inlined;
3589	};
3590
3591	static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent, bool is_cross)
3592	{
3593	int retval;
3594
3595	ent->is_dir = true;
3596	if (!is_cross)
3597	return 0;
3598
3599	ent->dir_bh = ext4_get_first_dir_block(handle, inode: ent->inode,
3600	retval: &retval, parent_de: &ent->parent_de,
3601	inlined: &ent->dir_inlined);
3602	if (!ent->dir_bh)
3603	return retval;
3604	if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
3605	return -EFSCORRUPTED;
3606	BUFFER_TRACE(ent->dir_bh, "get_write_access");
3607	return ext4_journal_get_write_access(handle, ent->dir->i_sb,
3608	ent->dir_bh, EXT4_JTR_NONE);
3609	}
3610
3611	static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent,
3612	unsigned dir_ino)
3613	{
3614	int retval;
3615
3616	if (!ent->dir_bh)
3617	return 0;
3618
3619	ent->parent_de->inode = cpu_to_le32(dir_ino);
3620	BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata");
3621	if (!ent->dir_inlined) {
3622	if (is_dx(ent->inode)) {
3623	retval = ext4_handle_dirty_dx_node(handle,
3624	inode: ent->inode,
3625	bh: ent->dir_bh);
3626	} else {
3627	retval = ext4_handle_dirty_dirblock(handle, inode: ent->inode,
3628	bh: ent->dir_bh);
3629	}
3630	} else {
3631	retval = ext4_mark_inode_dirty(handle, ent->inode);
3632	}
3633	if (retval) {
3634	ext4_std_error(ent->dir->i_sb, retval);
3635	return retval;
3636	}
3637	return 0;
3638	}
3639
3640	static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
3641	unsigned ino, unsigned file_type)
3642	{
3643	int retval, retval2;
3644
3645	BUFFER_TRACE(ent->bh, "get write access");
3646	retval = ext4_journal_get_write_access(handle, ent->dir->i_sb, ent->bh,
3647	EXT4_JTR_NONE);
3648	if (retval)
3649	return retval;
3650	ent->de->inode = cpu_to_le32(ino);
3651	if (ext4_has_feature_filetype(sb: ent->dir->i_sb))
3652	ent->de->file_type = file_type;
3653	inode_inc_iversion(inode: ent->dir);
3654	inode_set_mtime_to_ts(inode: ent->dir, ts: inode_set_ctime_current(inode: ent->dir));
3655	retval = ext4_mark_inode_dirty(handle, ent->dir);
3656	BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata");
3657	if (!ent->inlined) {
3658	retval2 = ext4_handle_dirty_dirblock(handle, inode: ent->dir, bh: ent->bh);
3659	if (unlikely(retval2)) {
3660	ext4_std_error(ent->dir->i_sb, retval2);
3661	return retval2;
3662	}
3663	}
3664	return retval;
3665	}
3666
3667	static void ext4_resetent(handle_t *handle, struct ext4_renament *ent,
3668	unsigned ino, unsigned file_type)
3669	{
3670	struct ext4_renament old = *ent;
3671	int retval = 0;
3672
3673	/*
3674	* old->de could have moved from under us during make indexed dir,
3675	* so the old->de may no longer valid and need to find it again
3676	* before reset old inode info.
3677	*/
3678	old.bh = ext4_find_entry(dir: old.dir, d_name: &old.dentry->d_name, res_dir: &old.de,
3679	inlined: &old.inlined);
3680	if (IS_ERR(ptr: old.bh))
3681	retval = PTR_ERR(ptr: old.bh);
3682	if (!old.bh)
3683	retval = -ENOENT;
3684	if (retval) {
3685	ext4_std_error(old.dir->i_sb, retval);
3686	return;
3687	}
3688
3689	ext4_setent(handle, ent: &old, ino, file_type);
3690	brelse(bh: old.bh);
3691	}
3692
3693	static int ext4_find_delete_entry(handle_t *handle, struct inode *dir,
3694	const struct qstr *d_name)
3695	{
3696	int retval = -ENOENT;
3697	struct buffer_head *bh;
3698	struct ext4_dir_entry_2 *de;
3699
3700	bh = ext4_find_entry(dir, d_name, res_dir: &de, NULL);
3701	if (IS_ERR(ptr: bh))
3702	return PTR_ERR(ptr: bh);
3703	if (bh) {
3704	retval = ext4_delete_entry(handle, dir, de_del: de, bh);
3705	brelse(bh);
3706	}
3707	return retval;
3708	}
3709
3710	static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent,
3711	int force_reread)
3712	{
3713	int retval;
3714	/*
3715	* ent->de could have moved from under us during htree split, so make
3716	* sure that we are deleting the right entry. We might also be pointing
3717	* to a stale entry in the unused part of ent->bh so just checking inum
3718	* and the name isn't enough.
3719	*/
3720	if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino ||
3721	ent->de->name_len != ent->dentry->d_name.len ||
3722	strncmp(ent->de->name, ent->dentry->d_name.name,
3723	ent->de->name_len) ||
3724	force_reread) {
3725	retval = ext4_find_delete_entry(handle, dir: ent->dir,
3726	d_name: &ent->dentry->d_name);
3727	} else {
3728	retval = ext4_delete_entry(handle, dir: ent->dir, de_del: ent->de, bh: ent->bh);
3729	if (retval == -ENOENT) {
3730	retval = ext4_find_delete_entry(handle, dir: ent->dir,
3731	d_name: &ent->dentry->d_name);
3732	}
3733	}
3734
3735	if (retval) {
3736	ext4_warning_inode(ent->dir,
3737	"Deleting old file: nlink %d, error=%d",
3738	ent->dir->i_nlink, retval);
3739	}
3740	}
3741
3742	static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent)
3743	{
3744	if (ent->dir_nlink_delta) {
3745	if (ent->dir_nlink_delta == -1)
3746	ext4_dec_count(inode: ent->dir);
3747	else
3748	ext4_inc_count(inode: ent->dir);
3749	ext4_mark_inode_dirty(handle, ent->dir);
3750	}
3751	}
3752
3753	static struct inode *ext4_whiteout_for_rename(struct mnt_idmap *idmap,
3754	struct ext4_renament *ent,
3755	int credits, handle_t **h)
3756	{
3757	struct inode *wh;
3758	handle_t *handle;
3759	int retries = 0;
3760
3761	/*
3762	* for inode block, sb block, group summaries,
3763	* and inode bitmap
3764	*/
3765	credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) +
3766	EXT4_XATTR_TRANS_BLOCKS + 4);
3767	retry:
3768	wh = ext4_new_inode_start_handle(idmap, ent->dir,
3769	S_IFCHR | WHITEOUT_MODE,
3770	&ent->dentry->d_name, 0, NULL,
3771	EXT4_HT_DIR, credits);
3772
3773	handle = ext4_journal_current_handle();
3774	if (IS_ERR(ptr: wh)) {
3775	if (handle)
3776	ext4_journal_stop(handle);
3777	if (PTR_ERR(ptr: wh) == -ENOSPC &&
3778	ext4_should_retry_alloc(sb: ent->dir->i_sb, retries: &retries))
3779	goto retry;
3780	} else {
3781	*h = handle;
3782	init_special_inode(wh, wh->i_mode, WHITEOUT_DEV);
3783	wh->i_op = &ext4_special_inode_operations;
3784	}
3785	return wh;
3786	}
3787
3788	/*
3789	* Anybody can rename anything with this: the permission checks are left to the
3790	* higher-level routines.
3791	*
3792	* n.b. old_{dentry,inode) refers to the source dentry/inode
3793	* while new_{dentry,inode) refers to the destination dentry/inode
3794	* This comes from rename(const char *oldpath, const char *newpath)
3795	*/
3796	static int ext4_rename(struct mnt_idmap *idmap, struct inode *old_dir,
3797	struct dentry *old_dentry, struct inode *new_dir,
3798	struct dentry *new_dentry, unsigned int flags)
3799	{
3800	handle_t *handle = NULL;
3801	struct ext4_renament old = {
3802	.dir = old_dir,
3803	.dentry = old_dentry,
3804	.inode = d_inode(dentry: old_dentry),
3805	};
3806	struct ext4_renament new = {
3807	.dir = new_dir,
3808	.dentry = new_dentry,
3809	.inode = d_inode(dentry: new_dentry),
3810	};
3811	int force_reread;
3812	int retval;
3813	struct inode *whiteout = NULL;
3814	int credits;
3815	u8 old_file_type;
3816
3817	if (new.inode && new.inode->i_nlink == 0) {
3818	EXT4_ERROR_INODE(new.inode,
3819	"target of rename is already freed");
3820	return -EFSCORRUPTED;
3821	}
3822
3823	if ((ext4_test_inode_flag(inode: new_dir, bit: EXT4_INODE_PROJINHERIT)) &&
3824	(!projid_eq(EXT4_I(new_dir)->i_projid,
3825	EXT4_I(old_dentry->d_inode)->i_projid)))
3826	return -EXDEV;
3827
3828	retval = dquot_initialize(inode: old.dir);
3829	if (retval)
3830	return retval;
3831	retval = dquot_initialize(inode: old.inode);
3832	if (retval)
3833	return retval;
3834	retval = dquot_initialize(inode: new.dir);
3835	if (retval)
3836	return retval;
3837
3838	/* Initialize quotas before so that eventual writes go
3839	* in separate transaction */
3840	if (new.inode) {
3841	retval = dquot_initialize(inode: new.inode);
3842	if (retval)
3843	return retval;
3844	}
3845
3846	old.bh = ext4_find_entry(dir: old.dir, d_name: &old.dentry->d_name, res_dir: &old.de,
3847	inlined: &old.inlined);
3848	if (IS_ERR(ptr: old.bh))
3849	return PTR_ERR(ptr: old.bh);
3850
3851	/*
3852	* Check for inode number is _not_ due to possible IO errors.
3853	* We might rmdir the source, keep it as pwd of some process
3854	* and merrily kill the link to whatever was created under the
3855	* same name. Goodbye sticky bit ;-<
3856	*/
3857	retval = -ENOENT;
3858	if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
3859	goto release_bh;
3860
3861	new.bh = ext4_find_entry(dir: new.dir, d_name: &new.dentry->d_name,
3862	res_dir: &new.de, inlined: &new.inlined);
3863	if (IS_ERR(ptr: new.bh)) {
3864	retval = PTR_ERR(ptr: new.bh);
3865	new.bh = NULL;
3866	goto release_bh;
3867	}
3868	if (new.bh) {
3869	if (!new.inode) {
3870	brelse(bh: new.bh);
3871	new.bh = NULL;
3872	}
3873	}
3874	if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC))
3875	ext4_alloc_da_blocks(inode: old.inode);
3876
3877	credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
3878	EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
3879	if (!(flags & RENAME_WHITEOUT)) {
3880	handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits);
3881	if (IS_ERR(ptr: handle)) {
3882	retval = PTR_ERR(ptr: handle);
3883	goto release_bh;
3884	}
3885	} else {
3886	whiteout = ext4_whiteout_for_rename(idmap, ent: &old, credits, h: &handle);
3887	if (IS_ERR(ptr: whiteout)) {
3888	retval = PTR_ERR(ptr: whiteout);
3889	goto release_bh;
3890	}
3891	}
3892
3893	old_file_type = old.de->file_type;
3894	if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
3895	ext4_handle_sync(handle);
3896
3897	if (S_ISDIR(old.inode->i_mode)) {
3898	if (new.inode) {
3899	retval = -ENOTEMPTY;
3900	if (!ext4_empty_dir(inode: new.inode))
3901	goto end_rename;
3902	} else {
3903	retval = -EMLINK;
3904	if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir))
3905	goto end_rename;
3906	}
3907	retval = ext4_rename_dir_prepare(handle, ent: &old, is_cross: new.dir != old.dir);
3908	if (retval)
3909	goto end_rename;
3910	}
3911	/*
3912	* If we're renaming a file within an inline_data dir and adding or
3913	* setting the new dirent causes a conversion from inline_data to
3914	* extents/blockmap, we need to force the dirent delete code to
3915	* re-read the directory, or else we end up trying to delete a dirent
3916	* from what is now the extent tree root (or a block map).
3917	*/
3918	force_reread = (new.dir->i_ino == old.dir->i_ino &&
3919	ext4_test_inode_flag(inode: new.dir, bit: EXT4_INODE_INLINE_DATA));
3920
3921	if (whiteout) {
3922	/*
3923	* Do this before adding a new entry, so the old entry is sure
3924	* to be still pointing to the valid old entry.
3925	*/
3926	retval = ext4_setent(handle, ent: &old, ino: whiteout->i_ino,
3927	EXT4_FT_CHRDEV);
3928	if (retval)
3929	goto end_rename;
3930	retval = ext4_mark_inode_dirty(handle, whiteout);
3931	if (unlikely(retval))
3932	goto end_rename;
3933
3934	}
3935	if (!new.bh) {
3936	retval = ext4_add_entry(handle, dentry: new.dentry, inode: old.inode);
3937	if (retval)
3938	goto end_rename;
3939	} else {
3940	retval = ext4_setent(handle, ent: &new,
3941	ino: old.inode->i_ino, file_type: old_file_type);
3942	if (retval)
3943	goto end_rename;
3944	}
3945	if (force_reread)
3946	force_reread = !ext4_test_inode_flag(inode: new.dir,
3947	bit: EXT4_INODE_INLINE_DATA);
3948
3949	/*
3950	* Like most other Unix systems, set the ctime for inodes on a
3951	* rename.
3952	*/
3953	inode_set_ctime_current(inode: old.inode);
3954	retval = ext4_mark_inode_dirty(handle, old.inode);
3955	if (unlikely(retval))
3956	goto end_rename;
3957
3958	if (!whiteout) {
3959	/*
3960	* ok, that's it
3961	*/
3962	ext4_rename_delete(handle, ent: &old, force_reread);
3963	}
3964
3965	if (new.inode) {
3966	ext4_dec_count(inode: new.inode);
3967	inode_set_ctime_current(inode: new.inode);
3968	}
3969	inode_set_mtime_to_ts(inode: old.dir, ts: inode_set_ctime_current(inode: old.dir));
3970	ext4_update_dx_flag(inode: old.dir);
3971	if (old.is_dir) {
3972	retval = ext4_rename_dir_finish(handle, ent: &old, dir_ino: new.dir->i_ino);
3973	if (retval)
3974	goto end_rename;
3975
3976	ext4_dec_count(inode: old.dir);
3977	if (new.inode) {
3978	/* checked ext4_empty_dir above, can't have another
3979	* parent, ext4_dec_count() won't work for many-linked
3980	* dirs */
3981	clear_nlink(inode: new.inode);
3982	} else {
3983	ext4_inc_count(inode: new.dir);
3984	ext4_update_dx_flag(inode: new.dir);
3985	retval = ext4_mark_inode_dirty(handle, new.dir);
3986	if (unlikely(retval))
3987	goto end_rename;
3988	}
3989	}
3990	retval = ext4_mark_inode_dirty(handle, old.dir);
3991	if (unlikely(retval))
3992	goto end_rename;
3993
3994	if (old.is_dir) {
3995	/*
3996	* We disable fast commits here that's because the
3997	* replay code is not yet capable of changing dot dot
3998	* dirents in directories.
3999	*/
4000	ext4_fc_mark_ineligible(sb: old.inode->i_sb,
4001	reason: EXT4_FC_REASON_RENAME_DIR, handle);
4002	} else {
4003	struct super_block *sb = old.inode->i_sb;
4004
4005	if (new.inode)
4006	ext4_fc_track_unlink(handle, dentry: new.dentry);
4007	if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
4008	!(EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY) &&
4009	!(ext4_test_mount_flag(sb, bit: EXT4_MF_FC_INELIGIBLE))) {
4010	__ext4_fc_track_link(handle, inode: old.inode, dentry: new.dentry);
4011	__ext4_fc_track_unlink(handle, inode: old.inode, dentry: old.dentry);
4012	if (whiteout)
4013	__ext4_fc_track_create(handle, inode: whiteout,
4014	dentry: old.dentry);
4015	}
4016	}
4017
4018	if (new.inode) {
4019	retval = ext4_mark_inode_dirty(handle, new.inode);
4020	if (unlikely(retval))
4021	goto end_rename;
4022	if (!new.inode->i_nlink)
4023	ext4_orphan_add(handle, new.inode);
4024	}
4025	retval = 0;
4026
4027	end_rename:
4028	if (whiteout) {
4029	if (retval) {
4030	ext4_resetent(handle, ent: &old,
4031	ino: old.inode->i_ino, file_type: old_file_type);
4032	drop_nlink(inode: whiteout);
4033	ext4_mark_inode_dirty(handle, whiteout);
4034	ext4_orphan_add(handle, whiteout);
4035	}
4036	unlock_new_inode(whiteout);
4037	ext4_journal_stop(handle);
4038	iput(whiteout);
4039	} else {
4040	ext4_journal_stop(handle);
4041	}
4042	release_bh:
4043	brelse(bh: old.dir_bh);
4044	brelse(bh: old.bh);
4045	brelse(bh: new.bh);
4046
4047	return retval;
4048	}
4049
4050	static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
4051	struct inode *new_dir, struct dentry *new_dentry)
4052	{
4053	handle_t *handle = NULL;
4054	struct ext4_renament old = {
4055	.dir = old_dir,
4056	.dentry = old_dentry,
4057	.inode = d_inode(dentry: old_dentry),
4058	};
4059	struct ext4_renament new = {
4060	.dir = new_dir,
4061	.dentry = new_dentry,
4062	.inode = d_inode(dentry: new_dentry),
4063	};
4064	u8 new_file_type;
4065	int retval;
4066
4067	if ((ext4_test_inode_flag(inode: new_dir, bit: EXT4_INODE_PROJINHERIT) &&
4068	!projid_eq(EXT4_I(new_dir)->i_projid,
4069	EXT4_I(old_dentry->d_inode)->i_projid)) ||
4070	(ext4_test_inode_flag(inode: old_dir, bit: EXT4_INODE_PROJINHERIT) &&
4071	!projid_eq(EXT4_I(old_dir)->i_projid,
4072	EXT4_I(new_dentry->d_inode)->i_projid)))
4073	return -EXDEV;
4074
4075	retval = dquot_initialize(inode: old.dir);
4076	if (retval)
4077	return retval;
4078	retval = dquot_initialize(inode: new.dir);
4079	if (retval)
4080	return retval;
4081
4082	old.bh = ext4_find_entry(dir: old.dir, d_name: &old.dentry->d_name,
4083	res_dir: &old.de, inlined: &old.inlined);
4084	if (IS_ERR(ptr: old.bh))
4085	return PTR_ERR(ptr: old.bh);
4086	/*
4087	* Check for inode number is _not_ due to possible IO errors.
4088	* We might rmdir the source, keep it as pwd of some process
4089	* and merrily kill the link to whatever was created under the
4090	* same name. Goodbye sticky bit ;-<
4091	*/
4092	retval = -ENOENT;
4093	if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
4094	goto end_rename;
4095
4096	new.bh = ext4_find_entry(dir: new.dir, d_name: &new.dentry->d_name,
4097	res_dir: &new.de, inlined: &new.inlined);
4098	if (IS_ERR(ptr: new.bh)) {
4099	retval = PTR_ERR(ptr: new.bh);
4100	new.bh = NULL;
4101	goto end_rename;
4102	}
4103
4104	/* RENAME_EXCHANGE case: old *and* new must both exist */
4105	if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino)
4106	goto end_rename;
4107
4108	handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
4109	(2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
4110	2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
4111	if (IS_ERR(ptr: handle)) {
4112	retval = PTR_ERR(ptr: handle);
4113	handle = NULL;
4114	goto end_rename;
4115	}
4116
4117	if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
4118	ext4_handle_sync(handle);
4119
4120	if (S_ISDIR(old.inode->i_mode)) {
4121	retval = ext4_rename_dir_prepare(handle, ent: &old, is_cross: new.dir != old.dir);
4122	if (retval)
4123	goto end_rename;
4124	}
4125	if (S_ISDIR(new.inode->i_mode)) {
4126	retval = ext4_rename_dir_prepare(handle, ent: &new, is_cross: new.dir != old.dir);
4127	if (retval)
4128	goto end_rename;
4129	}
4130
4131	/*
4132	* Other than the special case of overwriting a directory, parents'
4133	* nlink only needs to be modified if this is a cross directory rename.
4134	*/
4135	if (old.dir != new.dir && old.is_dir != new.is_dir) {
4136	old.dir_nlink_delta = old.is_dir ? -1 : 1;
4137	new.dir_nlink_delta = -old.dir_nlink_delta;
4138	retval = -EMLINK;
4139	if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) ||
4140	(new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir)))
4141	goto end_rename;
4142	}
4143
4144	new_file_type = new.de->file_type;
4145	retval = ext4_setent(handle, ent: &new, ino: old.inode->i_ino, file_type: old.de->file_type);
4146	if (retval)
4147	goto end_rename;
4148
4149	retval = ext4_setent(handle, ent: &old, ino: new.inode->i_ino, file_type: new_file_type);
4150	if (retval)
4151	goto end_rename;
4152
4153	/*
4154	* Like most other Unix systems, set the ctime for inodes on a
4155	* rename.
4156	*/
4157	inode_set_ctime_current(inode: old.inode);
4158	inode_set_ctime_current(inode: new.inode);
4159	retval = ext4_mark_inode_dirty(handle, old.inode);
4160	if (unlikely(retval))
4161	goto end_rename;
4162	retval = ext4_mark_inode_dirty(handle, new.inode);
4163	if (unlikely(retval))
4164	goto end_rename;
4165	ext4_fc_mark_ineligible(sb: new.inode->i_sb,
4166	reason: EXT4_FC_REASON_CROSS_RENAME, handle);
4167	if (old.dir_bh) {
4168	retval = ext4_rename_dir_finish(handle, ent: &old, dir_ino: new.dir->i_ino);
4169	if (retval)
4170	goto end_rename;
4171	}
4172	if (new.dir_bh) {
4173	retval = ext4_rename_dir_finish(handle, ent: &new, dir_ino: old.dir->i_ino);
4174	if (retval)
4175	goto end_rename;
4176	}
4177	ext4_update_dir_count(handle, ent: &old);
4178	ext4_update_dir_count(handle, ent: &new);
4179	retval = 0;
4180
4181	end_rename:
4182	brelse(bh: old.dir_bh);
4183	brelse(bh: new.dir_bh);
4184	brelse(bh: old.bh);
4185	brelse(bh: new.bh);
4186	if (handle)
4187	ext4_journal_stop(handle);
4188	return retval;
4189	}
4190
4191	static int ext4_rename2(struct mnt_idmap *idmap,
4192	struct inode *old_dir, struct dentry *old_dentry,
4193	struct inode *new_dir, struct dentry *new_dentry,
4194	unsigned int flags)
4195	{
4196	int err;
4197
4198	if (unlikely(ext4_forced_shutdown(old_dir->i_sb)))
4199	return -EIO;
4200
4201	if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
4202	return -EINVAL;
4203
4204	err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry,
4205	flags);
4206	if (err)
4207	return err;
4208
4209	if (flags & RENAME_EXCHANGE) {
4210	return ext4_cross_rename(old_dir, old_dentry,
4211	new_dir, new_dentry);
4212	}
4213
4214	return ext4_rename(idmap, old_dir, old_dentry, new_dir, new_dentry, flags);
4215	}
4216
4217	/*
4218	* directories can handle most operations...
4219	*/
4220	const struct inode_operations ext4_dir_inode_operations = {
4221	.create = ext4_create,
4222	.lookup = ext4_lookup,
4223	.link = ext4_link,
4224	.unlink = ext4_unlink,
4225	.symlink = ext4_symlink,
4226	.mkdir = ext4_mkdir,
4227	.rmdir = ext4_rmdir,
4228	.mknod = ext4_mknod,
4229	.tmpfile = ext4_tmpfile,
4230	.rename = ext4_rename2,
4231	.setattr = ext4_setattr,
4232	.getattr = ext4_getattr,
4233	.listxattr = ext4_listxattr,
4234	.get_inode_acl = ext4_get_acl,
4235	.set_acl = ext4_set_acl,
4236	.fiemap = ext4_fiemap,
4237	.fileattr_get = ext4_fileattr_get,
4238	.fileattr_set = ext4_fileattr_set,
4239	};
4240
4241	const struct inode_operations ext4_special_inode_operations = {
4242	.setattr = ext4_setattr,
4243	.getattr = ext4_getattr,
4244	.listxattr = ext4_listxattr,
4245	.get_inode_acl = ext4_get_acl,
4246	.set_acl = ext4_set_acl,
4247	};
4248