xref: /openbmc/linux/fs/ocfs2/dir.c (revision 020c5260)
1 /* -*- mode: c; c-basic-offset: 8; -*-
2  * vim: noexpandtab sw=8 ts=8 sts=0:
3  *
4  * dir.c
5  *
6  * Creates, reads, walks and deletes directory-nodes
7  *
8  * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
9  *
10  *  Portions of this code from linux/fs/ext3/dir.c
11  *
12  *  Copyright (C) 1992, 1993, 1994, 1995
13  *  Remy Card (card@masi.ibp.fr)
14  *  Laboratoire MASI - Institut Blaise pascal
15  *  Universite Pierre et Marie Curie (Paris VI)
16  *
17  *   from
18  *
19  *   linux/fs/minix/dir.c
20  *
21  *   Copyright (C) 1991, 1992 Linus Torvalds
22  *
23  * This program is free software; you can redistribute it and/or
24  * modify it under the terms of the GNU General Public
25  * License as published by the Free Software Foundation; either
26  * version 2 of the License, or (at your option) any later version.
27  *
28  * This program is distributed in the hope that it will be useful,
29  * but WITHOUT ANY WARRANTY; without even the implied warranty of
30  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
31  * General Public License for more details.
32  *
33  * You should have received a copy of the GNU General Public
34  * License along with this program; if not, write to the
35  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
36  * Boston, MA 021110-1307, USA.
37  */
38 
39 #include <linux/fs.h>
40 #include <linux/types.h>
41 #include <linux/slab.h>
42 #include <linux/highmem.h>
43 #include <linux/quotaops.h>
44 #include <linux/sort.h>
45 
46 #include <cluster/masklog.h>
47 
48 #include "ocfs2.h"
49 
50 #include "alloc.h"
51 #include "blockcheck.h"
52 #include "dir.h"
53 #include "dlmglue.h"
54 #include "extent_map.h"
55 #include "file.h"
56 #include "inode.h"
57 #include "journal.h"
58 #include "namei.h"
59 #include "suballoc.h"
60 #include "super.h"
61 #include "sysfile.h"
62 #include "uptodate.h"
63 #include "ocfs2_trace.h"
64 
65 #include "buffer_head_io.h"
66 
67 #define NAMEI_RA_CHUNKS  2
68 #define NAMEI_RA_BLOCKS  4
69 #define NAMEI_RA_SIZE        (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
70 
71 static unsigned char ocfs2_filetype_table[] = {
72 	DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
73 };
74 
75 static int ocfs2_do_extend_dir(struct super_block *sb,
76 			       handle_t *handle,
77 			       struct inode *dir,
78 			       struct buffer_head *parent_fe_bh,
79 			       struct ocfs2_alloc_context *data_ac,
80 			       struct ocfs2_alloc_context *meta_ac,
81 			       struct buffer_head **new_bh);
82 static int ocfs2_dir_indexed(struct inode *inode);
83 
84 /*
85  * These are distinct checks because future versions of the file system will
86  * want to have a trailing dirent structure independent of indexing.
87  */
88 static int ocfs2_supports_dir_trailer(struct inode *dir)
89 {
90 	struct ocfs2_super *osb = OCFS2_SB(dir->i_sb);
91 
92 	if (OCFS2_I(dir)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
93 		return 0;
94 
95 	return ocfs2_meta_ecc(osb) || ocfs2_dir_indexed(dir);
96 }
97 
98 /*
99  * "new' here refers to the point at which we're creating a new
100  * directory via "mkdir()", but also when we're expanding an inline
101  * directory. In either case, we don't yet have the indexing bit set
102  * on the directory, so the standard checks will fail in when metaecc
103  * is turned off. Only directory-initialization type functions should
104  * use this then. Everything else wants ocfs2_supports_dir_trailer()
105  */
106 static int ocfs2_new_dir_wants_trailer(struct inode *dir)
107 {
108 	struct ocfs2_super *osb = OCFS2_SB(dir->i_sb);
109 
110 	return ocfs2_meta_ecc(osb) ||
111 		ocfs2_supports_indexed_dirs(osb);
112 }
113 
114 static inline unsigned int ocfs2_dir_trailer_blk_off(struct super_block *sb)
115 {
116 	return sb->s_blocksize - sizeof(struct ocfs2_dir_block_trailer);
117 }
118 
119 #define ocfs2_trailer_from_bh(_bh, _sb) ((struct ocfs2_dir_block_trailer *) ((_bh)->b_data + ocfs2_dir_trailer_blk_off((_sb))))
120 
121 /* XXX ocfs2_block_dqtrailer() is similar but not quite - can we make
122  * them more consistent? */
123 struct ocfs2_dir_block_trailer *ocfs2_dir_trailer_from_size(int blocksize,
124 							    void *data)
125 {
126 	char *p = data;
127 
128 	p += blocksize - sizeof(struct ocfs2_dir_block_trailer);
129 	return (struct ocfs2_dir_block_trailer *)p;
130 }
131 
132 /*
133  * XXX: This is executed once on every dirent. We should consider optimizing
134  * it.
135  */
136 static int ocfs2_skip_dir_trailer(struct inode *dir,
137 				  struct ocfs2_dir_entry *de,
138 				  unsigned long offset,
139 				  unsigned long blklen)
140 {
141 	unsigned long toff = blklen - sizeof(struct ocfs2_dir_block_trailer);
142 
143 	if (!ocfs2_supports_dir_trailer(dir))
144 		return 0;
145 
146 	if (offset != toff)
147 		return 0;
148 
149 	return 1;
150 }
151 
152 static void ocfs2_init_dir_trailer(struct inode *inode,
153 				   struct buffer_head *bh, u16 rec_len)
154 {
155 	struct ocfs2_dir_block_trailer *trailer;
156 
157 	trailer = ocfs2_trailer_from_bh(bh, inode->i_sb);
158 	strcpy(trailer->db_signature, OCFS2_DIR_TRAILER_SIGNATURE);
159 	trailer->db_compat_rec_len =
160 			cpu_to_le16(sizeof(struct ocfs2_dir_block_trailer));
161 	trailer->db_parent_dinode = cpu_to_le64(OCFS2_I(inode)->ip_blkno);
162 	trailer->db_blkno = cpu_to_le64(bh->b_blocknr);
163 	trailer->db_free_rec_len = cpu_to_le16(rec_len);
164 }
165 /*
166  * Link an unindexed block with a dir trailer structure into the index free
167  * list. This function will modify dirdata_bh, but assumes you've already
168  * passed it to the journal.
169  */
170 static int ocfs2_dx_dir_link_trailer(struct inode *dir, handle_t *handle,
171 				     struct buffer_head *dx_root_bh,
172 				     struct buffer_head *dirdata_bh)
173 {
174 	int ret;
175 	struct ocfs2_dx_root_block *dx_root;
176 	struct ocfs2_dir_block_trailer *trailer;
177 
178 	ret = ocfs2_journal_access_dr(handle, INODE_CACHE(dir), dx_root_bh,
179 				      OCFS2_JOURNAL_ACCESS_WRITE);
180 	if (ret) {
181 		mlog_errno(ret);
182 		goto out;
183 	}
184 	trailer = ocfs2_trailer_from_bh(dirdata_bh, dir->i_sb);
185 	dx_root = (struct ocfs2_dx_root_block *)dx_root_bh->b_data;
186 
187 	trailer->db_free_next = dx_root->dr_free_blk;
188 	dx_root->dr_free_blk = cpu_to_le64(dirdata_bh->b_blocknr);
189 
190 	ocfs2_journal_dirty(handle, dx_root_bh);
191 
192 out:
193 	return ret;
194 }
195 
196 static int ocfs2_free_list_at_root(struct ocfs2_dir_lookup_result *res)
197 {
198 	return res->dl_prev_leaf_bh == NULL;
199 }
200 
201 void ocfs2_free_dir_lookup_result(struct ocfs2_dir_lookup_result *res)
202 {
203 	brelse(res->dl_dx_root_bh);
204 	brelse(res->dl_leaf_bh);
205 	brelse(res->dl_dx_leaf_bh);
206 	brelse(res->dl_prev_leaf_bh);
207 }
208 
209 static int ocfs2_dir_indexed(struct inode *inode)
210 {
211 	if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INDEXED_DIR_FL)
212 		return 1;
213 	return 0;
214 }
215 
216 static inline int ocfs2_dx_root_inline(struct ocfs2_dx_root_block *dx_root)
217 {
218 	return dx_root->dr_flags & OCFS2_DX_FLAG_INLINE;
219 }
220 
221 /*
222  * Hashing code adapted from ext3
223  */
224 #define DELTA 0x9E3779B9
225 
226 static void TEA_transform(__u32 buf[4], __u32 const in[])
227 {
228 	__u32	sum = 0;
229 	__u32	b0 = buf[0], b1 = buf[1];
230 	__u32	a = in[0], b = in[1], c = in[2], d = in[3];
231 	int	n = 16;
232 
233 	do {
234 		sum += DELTA;
235 		b0 += ((b1 << 4)+a) ^ (b1+sum) ^ ((b1 >> 5)+b);
236 		b1 += ((b0 << 4)+c) ^ (b0+sum) ^ ((b0 >> 5)+d);
237 	} while (--n);
238 
239 	buf[0] += b0;
240 	buf[1] += b1;
241 }
242 
243 static void str2hashbuf(const char *msg, int len, __u32 *buf, int num)
244 {
245 	__u32	pad, val;
246 	int	i;
247 
248 	pad = (__u32)len | ((__u32)len << 8);
249 	pad |= pad << 16;
250 
251 	val = pad;
252 	if (len > num*4)
253 		len = num * 4;
254 	for (i = 0; i < len; i++) {
255 		if ((i % 4) == 0)
256 			val = pad;
257 		val = msg[i] + (val << 8);
258 		if ((i % 4) == 3) {
259 			*buf++ = val;
260 			val = pad;
261 			num--;
262 		}
263 	}
264 	if (--num >= 0)
265 		*buf++ = val;
266 	while (--num >= 0)
267 		*buf++ = pad;
268 }
269 
270 static void ocfs2_dx_dir_name_hash(struct inode *dir, const char *name, int len,
271 				   struct ocfs2_dx_hinfo *hinfo)
272 {
273 	struct ocfs2_super *osb = OCFS2_SB(dir->i_sb);
274 	const char	*p;
275 	__u32		in[8], buf[4];
276 
277 	/*
278 	 * XXX: Is this really necessary, if the index is never looked
279 	 * at by readdir? Is a hash value of '0' a bad idea?
280 	 */
281 	if ((len == 1 && !strncmp(".", name, 1)) ||
282 	    (len == 2 && !strncmp("..", name, 2))) {
283 		buf[0] = buf[1] = 0;
284 		goto out;
285 	}
286 
287 #ifdef OCFS2_DEBUG_DX_DIRS
288 	/*
289 	 * This makes it very easy to debug indexing problems. We
290 	 * should never allow this to be selected without hand editing
291 	 * this file though.
292 	 */
293 	buf[0] = buf[1] = len;
294 	goto out;
295 #endif
296 
297 	memcpy(buf, osb->osb_dx_seed, sizeof(buf));
298 
299 	p = name;
300 	while (len > 0) {
301 		str2hashbuf(p, len, in, 4);
302 		TEA_transform(buf, in);
303 		len -= 16;
304 		p += 16;
305 	}
306 
307 out:
308 	hinfo->major_hash = buf[0];
309 	hinfo->minor_hash = buf[1];
310 }
311 
312 /*
313  * bh passed here can be an inode block or a dir data block, depending
314  * on the inode inline data flag.
315  */
316 static int ocfs2_check_dir_entry(struct inode * dir,
317 				 struct ocfs2_dir_entry * de,
318 				 struct buffer_head * bh,
319 				 unsigned long offset)
320 {
321 	const char *error_msg = NULL;
322 	const int rlen = le16_to_cpu(de->rec_len);
323 
324 	if (unlikely(rlen < OCFS2_DIR_REC_LEN(1)))
325 		error_msg = "rec_len is smaller than minimal";
326 	else if (unlikely(rlen % 4 != 0))
327 		error_msg = "rec_len % 4 != 0";
328 	else if (unlikely(rlen < OCFS2_DIR_REC_LEN(de->name_len)))
329 		error_msg = "rec_len is too small for name_len";
330 	else if (unlikely(
331 		 ((char *) de - bh->b_data) + rlen > dir->i_sb->s_blocksize))
332 		error_msg = "directory entry across blocks";
333 
334 	if (unlikely(error_msg != NULL))
335 		mlog(ML_ERROR, "bad entry in directory #%llu: %s - "
336 		     "offset=%lu, inode=%llu, rec_len=%d, name_len=%d\n",
337 		     (unsigned long long)OCFS2_I(dir)->ip_blkno, error_msg,
338 		     offset, (unsigned long long)le64_to_cpu(de->inode), rlen,
339 		     de->name_len);
340 
341 	return error_msg == NULL ? 1 : 0;
342 }
343 
344 static inline int ocfs2_match(int len,
345 			      const char * const name,
346 			      struct ocfs2_dir_entry *de)
347 {
348 	if (len != de->name_len)
349 		return 0;
350 	if (!de->inode)
351 		return 0;
352 	return !memcmp(name, de->name, len);
353 }
354 
355 /*
356  * Returns 0 if not found, -1 on failure, and 1 on success
357  */
358 static inline int ocfs2_search_dirblock(struct buffer_head *bh,
359 					struct inode *dir,
360 					const char *name, int namelen,
361 					unsigned long offset,
362 					char *first_de,
363 					unsigned int bytes,
364 					struct ocfs2_dir_entry **res_dir)
365 {
366 	struct ocfs2_dir_entry *de;
367 	char *dlimit, *de_buf;
368 	int de_len;
369 	int ret = 0;
370 
371 	de_buf = first_de;
372 	dlimit = de_buf + bytes;
373 
374 	while (de_buf < dlimit) {
375 		/* this code is executed quadratically often */
376 		/* do minimal checking `by hand' */
377 
378 		de = (struct ocfs2_dir_entry *) de_buf;
379 
380 		if (de_buf + namelen <= dlimit &&
381 		    ocfs2_match(namelen, name, de)) {
382 			/* found a match - just to be sure, do a full check */
383 			if (!ocfs2_check_dir_entry(dir, de, bh, offset)) {
384 				ret = -1;
385 				goto bail;
386 			}
387 			*res_dir = de;
388 			ret = 1;
389 			goto bail;
390 		}
391 
392 		/* prevent looping on a bad block */
393 		de_len = le16_to_cpu(de->rec_len);
394 		if (de_len <= 0) {
395 			ret = -1;
396 			goto bail;
397 		}
398 
399 		de_buf += de_len;
400 		offset += de_len;
401 	}
402 
403 bail:
404 	trace_ocfs2_search_dirblock(ret);
405 	return ret;
406 }
407 
408 static struct buffer_head *ocfs2_find_entry_id(const char *name,
409 					       int namelen,
410 					       struct inode *dir,
411 					       struct ocfs2_dir_entry **res_dir)
412 {
413 	int ret, found;
414 	struct buffer_head *di_bh = NULL;
415 	struct ocfs2_dinode *di;
416 	struct ocfs2_inline_data *data;
417 
418 	ret = ocfs2_read_inode_block(dir, &di_bh);
419 	if (ret) {
420 		mlog_errno(ret);
421 		goto out;
422 	}
423 
424 	di = (struct ocfs2_dinode *)di_bh->b_data;
425 	data = &di->id2.i_data;
426 
427 	found = ocfs2_search_dirblock(di_bh, dir, name, namelen, 0,
428 				      data->id_data, i_size_read(dir), res_dir);
429 	if (found == 1)
430 		return di_bh;
431 
432 	brelse(di_bh);
433 out:
434 	return NULL;
435 }
436 
437 static int ocfs2_validate_dir_block(struct super_block *sb,
438 				    struct buffer_head *bh)
439 {
440 	int rc;
441 	struct ocfs2_dir_block_trailer *trailer =
442 		ocfs2_trailer_from_bh(bh, sb);
443 
444 
445 	/*
446 	 * We don't validate dirents here, that's handled
447 	 * in-place when the code walks them.
448 	 */
449 	trace_ocfs2_validate_dir_block((unsigned long long)bh->b_blocknr);
450 
451 	BUG_ON(!buffer_uptodate(bh));
452 
453 	/*
454 	 * If the ecc fails, we return the error but otherwise
455 	 * leave the filesystem running.  We know any error is
456 	 * local to this block.
457 	 *
458 	 * Note that we are safe to call this even if the directory
459 	 * doesn't have a trailer.  Filesystems without metaecc will do
460 	 * nothing, and filesystems with it will have one.
461 	 */
462 	rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &trailer->db_check);
463 	if (rc)
464 		mlog(ML_ERROR, "Checksum failed for dinode %llu\n",
465 		     (unsigned long long)bh->b_blocknr);
466 
467 	return rc;
468 }
469 
470 /*
471  * Validate a directory trailer.
472  *
473  * We check the trailer here rather than in ocfs2_validate_dir_block()
474  * because that function doesn't have the inode to test.
475  */
476 static int ocfs2_check_dir_trailer(struct inode *dir, struct buffer_head *bh)
477 {
478 	int rc = 0;
479 	struct ocfs2_dir_block_trailer *trailer;
480 
481 	trailer = ocfs2_trailer_from_bh(bh, dir->i_sb);
482 	if (!OCFS2_IS_VALID_DIR_TRAILER(trailer)) {
483 		rc = ocfs2_error(dir->i_sb,
484 				 "Invalid dirblock #%llu: signature = %.*s\n",
485 				 (unsigned long long)bh->b_blocknr, 7,
486 				 trailer->db_signature);
487 		goto out;
488 	}
489 	if (le64_to_cpu(trailer->db_blkno) != bh->b_blocknr) {
490 		rc = ocfs2_error(dir->i_sb,
491 				 "Directory block #%llu has an invalid db_blkno of %llu\n",
492 				 (unsigned long long)bh->b_blocknr,
493 				 (unsigned long long)le64_to_cpu(trailer->db_blkno));
494 		goto out;
495 	}
496 	if (le64_to_cpu(trailer->db_parent_dinode) !=
497 	    OCFS2_I(dir)->ip_blkno) {
498 		rc = ocfs2_error(dir->i_sb,
499 				 "Directory block #%llu on dinode #%llu has an invalid parent_dinode of %llu\n",
500 				 (unsigned long long)bh->b_blocknr,
501 				 (unsigned long long)OCFS2_I(dir)->ip_blkno,
502 				 (unsigned long long)le64_to_cpu(trailer->db_blkno));
503 		goto out;
504 	}
505 out:
506 	return rc;
507 }
508 
509 /*
510  * This function forces all errors to -EIO for consistency with its
511  * predecessor, ocfs2_bread().  We haven't audited what returning the
512  * real error codes would do to callers.  We log the real codes with
513  * mlog_errno() before we squash them.
514  */
515 static int ocfs2_read_dir_block(struct inode *inode, u64 v_block,
516 				struct buffer_head **bh, int flags)
517 {
518 	int rc = 0;
519 	struct buffer_head *tmp = *bh;
520 
521 	rc = ocfs2_read_virt_blocks(inode, v_block, 1, &tmp, flags,
522 				    ocfs2_validate_dir_block);
523 	if (rc) {
524 		mlog_errno(rc);
525 		goto out;
526 	}
527 
528 	if (!(flags & OCFS2_BH_READAHEAD) &&
529 	    ocfs2_supports_dir_trailer(inode)) {
530 		rc = ocfs2_check_dir_trailer(inode, tmp);
531 		if (rc) {
532 			if (!*bh)
533 				brelse(tmp);
534 			mlog_errno(rc);
535 			goto out;
536 		}
537 	}
538 
539 	/* If ocfs2_read_virt_blocks() got us a new bh, pass it up. */
540 	if (!*bh)
541 		*bh = tmp;
542 
543 out:
544 	return rc ? -EIO : 0;
545 }
546 
547 /*
548  * Read the block at 'phys' which belongs to this directory
549  * inode. This function does no virtual->physical block translation -
550  * what's passed in is assumed to be a valid directory block.
551  */
552 static int ocfs2_read_dir_block_direct(struct inode *dir, u64 phys,
553 				       struct buffer_head **bh)
554 {
555 	int ret;
556 	struct buffer_head *tmp = *bh;
557 
558 	ret = ocfs2_read_block(INODE_CACHE(dir), phys, &tmp,
559 			       ocfs2_validate_dir_block);
560 	if (ret) {
561 		mlog_errno(ret);
562 		goto out;
563 	}
564 
565 	if (ocfs2_supports_dir_trailer(dir)) {
566 		ret = ocfs2_check_dir_trailer(dir, tmp);
567 		if (ret) {
568 			if (!*bh)
569 				brelse(tmp);
570 			mlog_errno(ret);
571 			goto out;
572 		}
573 	}
574 
575 	if (!ret && !*bh)
576 		*bh = tmp;
577 out:
578 	return ret;
579 }
580 
581 static int ocfs2_validate_dx_root(struct super_block *sb,
582 				  struct buffer_head *bh)
583 {
584 	int ret;
585 	struct ocfs2_dx_root_block *dx_root;
586 
587 	BUG_ON(!buffer_uptodate(bh));
588 
589 	dx_root = (struct ocfs2_dx_root_block *) bh->b_data;
590 
591 	ret = ocfs2_validate_meta_ecc(sb, bh->b_data, &dx_root->dr_check);
592 	if (ret) {
593 		mlog(ML_ERROR,
594 		     "Checksum failed for dir index root block %llu\n",
595 		     (unsigned long long)bh->b_blocknr);
596 		return ret;
597 	}
598 
599 	if (!OCFS2_IS_VALID_DX_ROOT(dx_root)) {
600 		ret = ocfs2_error(sb,
601 				  "Dir Index Root # %llu has bad signature %.*s\n",
602 				  (unsigned long long)le64_to_cpu(dx_root->dr_blkno),
603 				  7, dx_root->dr_signature);
604 	}
605 
606 	return ret;
607 }
608 
609 static int ocfs2_read_dx_root(struct inode *dir, struct ocfs2_dinode *di,
610 			      struct buffer_head **dx_root_bh)
611 {
612 	int ret;
613 	u64 blkno = le64_to_cpu(di->i_dx_root);
614 	struct buffer_head *tmp = *dx_root_bh;
615 
616 	ret = ocfs2_read_block(INODE_CACHE(dir), blkno, &tmp,
617 			       ocfs2_validate_dx_root);
618 
619 	/* If ocfs2_read_block() got us a new bh, pass it up. */
620 	if (!ret && !*dx_root_bh)
621 		*dx_root_bh = tmp;
622 
623 	return ret;
624 }
625 
626 static int ocfs2_validate_dx_leaf(struct super_block *sb,
627 				  struct buffer_head *bh)
628 {
629 	int ret;
630 	struct ocfs2_dx_leaf *dx_leaf = (struct ocfs2_dx_leaf *)bh->b_data;
631 
632 	BUG_ON(!buffer_uptodate(bh));
633 
634 	ret = ocfs2_validate_meta_ecc(sb, bh->b_data, &dx_leaf->dl_check);
635 	if (ret) {
636 		mlog(ML_ERROR,
637 		     "Checksum failed for dir index leaf block %llu\n",
638 		     (unsigned long long)bh->b_blocknr);
639 		return ret;
640 	}
641 
642 	if (!OCFS2_IS_VALID_DX_LEAF(dx_leaf)) {
643 		ret = ocfs2_error(sb, "Dir Index Leaf has bad signature %.*s\n",
644 				  7, dx_leaf->dl_signature);
645 	}
646 
647 	return ret;
648 }
649 
650 static int ocfs2_read_dx_leaf(struct inode *dir, u64 blkno,
651 			      struct buffer_head **dx_leaf_bh)
652 {
653 	int ret;
654 	struct buffer_head *tmp = *dx_leaf_bh;
655 
656 	ret = ocfs2_read_block(INODE_CACHE(dir), blkno, &tmp,
657 			       ocfs2_validate_dx_leaf);
658 
659 	/* If ocfs2_read_block() got us a new bh, pass it up. */
660 	if (!ret && !*dx_leaf_bh)
661 		*dx_leaf_bh = tmp;
662 
663 	return ret;
664 }
665 
666 /*
667  * Read a series of dx_leaf blocks. This expects all buffer_head
668  * pointers to be NULL on function entry.
669  */
670 static int ocfs2_read_dx_leaves(struct inode *dir, u64 start, int num,
671 				struct buffer_head **dx_leaf_bhs)
672 {
673 	int ret;
674 
675 	ret = ocfs2_read_blocks(INODE_CACHE(dir), start, num, dx_leaf_bhs, 0,
676 				ocfs2_validate_dx_leaf);
677 	if (ret)
678 		mlog_errno(ret);
679 
680 	return ret;
681 }
682 
683 static struct buffer_head *ocfs2_find_entry_el(const char *name, int namelen,
684 					       struct inode *dir,
685 					       struct ocfs2_dir_entry **res_dir)
686 {
687 	struct super_block *sb;
688 	struct buffer_head *bh_use[NAMEI_RA_SIZE];
689 	struct buffer_head *bh, *ret = NULL;
690 	unsigned long start, block, b;
691 	int ra_max = 0;		/* Number of bh's in the readahead
692 				   buffer, bh_use[] */
693 	int ra_ptr = 0;		/* Current index into readahead
694 				   buffer */
695 	int num = 0;
696 	int nblocks, i, err;
697 
698 	sb = dir->i_sb;
699 
700 	nblocks = i_size_read(dir) >> sb->s_blocksize_bits;
701 	start = OCFS2_I(dir)->ip_dir_start_lookup;
702 	if (start >= nblocks)
703 		start = 0;
704 	block = start;
705 
706 restart:
707 	do {
708 		/*
709 		 * We deal with the read-ahead logic here.
710 		 */
711 		if (ra_ptr >= ra_max) {
712 			/* Refill the readahead buffer */
713 			ra_ptr = 0;
714 			b = block;
715 			for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
716 				/*
717 				 * Terminate if we reach the end of the
718 				 * directory and must wrap, or if our
719 				 * search has finished at this block.
720 				 */
721 				if (b >= nblocks || (num && block == start)) {
722 					bh_use[ra_max] = NULL;
723 					break;
724 				}
725 				num++;
726 
727 				bh = NULL;
728 				err = ocfs2_read_dir_block(dir, b++, &bh,
729 							   OCFS2_BH_READAHEAD);
730 				bh_use[ra_max] = bh;
731 			}
732 		}
733 		if ((bh = bh_use[ra_ptr++]) == NULL)
734 			goto next;
735 		if (ocfs2_read_dir_block(dir, block, &bh, 0)) {
736 			/* read error, skip block & hope for the best.
737 			 * ocfs2_read_dir_block() has released the bh. */
738 			mlog(ML_ERROR, "reading directory %llu, "
739 				    "offset %lu\n",
740 				    (unsigned long long)OCFS2_I(dir)->ip_blkno,
741 				    block);
742 			goto next;
743 		}
744 		i = ocfs2_search_dirblock(bh, dir, name, namelen,
745 					  block << sb->s_blocksize_bits,
746 					  bh->b_data, sb->s_blocksize,
747 					  res_dir);
748 		if (i == 1) {
749 			OCFS2_I(dir)->ip_dir_start_lookup = block;
750 			ret = bh;
751 			goto cleanup_and_exit;
752 		} else {
753 			brelse(bh);
754 			if (i < 0)
755 				goto cleanup_and_exit;
756 		}
757 	next:
758 		if (++block >= nblocks)
759 			block = 0;
760 	} while (block != start);
761 
762 	/*
763 	 * If the directory has grown while we were searching, then
764 	 * search the last part of the directory before giving up.
765 	 */
766 	block = nblocks;
767 	nblocks = i_size_read(dir) >> sb->s_blocksize_bits;
768 	if (block < nblocks) {
769 		start = 0;
770 		goto restart;
771 	}
772 
773 cleanup_and_exit:
774 	/* Clean up the read-ahead blocks */
775 	for (; ra_ptr < ra_max; ra_ptr++)
776 		brelse(bh_use[ra_ptr]);
777 
778 	trace_ocfs2_find_entry_el(ret);
779 	return ret;
780 }
781 
782 static int ocfs2_dx_dir_lookup_rec(struct inode *inode,
783 				   struct ocfs2_extent_list *el,
784 				   u32 major_hash,
785 				   u32 *ret_cpos,
786 				   u64 *ret_phys_blkno,
787 				   unsigned int *ret_clen)
788 {
789 	int ret = 0, i, found;
790 	struct buffer_head *eb_bh = NULL;
791 	struct ocfs2_extent_block *eb;
792 	struct ocfs2_extent_rec *rec = NULL;
793 
794 	if (el->l_tree_depth) {
795 		ret = ocfs2_find_leaf(INODE_CACHE(inode), el, major_hash,
796 				      &eb_bh);
797 		if (ret) {
798 			mlog_errno(ret);
799 			goto out;
800 		}
801 
802 		eb = (struct ocfs2_extent_block *) eb_bh->b_data;
803 		el = &eb->h_list;
804 
805 		if (el->l_tree_depth) {
806 			ret = ocfs2_error(inode->i_sb,
807 					  "Inode %lu has non zero tree depth in btree tree block %llu\n",
808 					  inode->i_ino,
809 					  (unsigned long long)eb_bh->b_blocknr);
810 			goto out;
811 		}
812 	}
813 
814 	found = 0;
815 	for (i = le16_to_cpu(el->l_next_free_rec) - 1; i >= 0; i--) {
816 		rec = &el->l_recs[i];
817 
818 		if (le32_to_cpu(rec->e_cpos) <= major_hash) {
819 			found = 1;
820 			break;
821 		}
822 	}
823 
824 	if (!found) {
825 		ret = ocfs2_error(inode->i_sb,
826 				  "Inode %lu has bad extent record (%u, %u, 0) in btree\n",
827 				  inode->i_ino,
828 				  le32_to_cpu(rec->e_cpos),
829 				  ocfs2_rec_clusters(el, rec));
830 		goto out;
831 	}
832 
833 	if (ret_phys_blkno)
834 		*ret_phys_blkno = le64_to_cpu(rec->e_blkno);
835 	if (ret_cpos)
836 		*ret_cpos = le32_to_cpu(rec->e_cpos);
837 	if (ret_clen)
838 		*ret_clen = le16_to_cpu(rec->e_leaf_clusters);
839 
840 out:
841 	brelse(eb_bh);
842 	return ret;
843 }
844 
845 /*
846  * Returns the block index, from the start of the cluster which this
847  * hash belongs too.
848  */
849 static inline unsigned int __ocfs2_dx_dir_hash_idx(struct ocfs2_super *osb,
850 						   u32 minor_hash)
851 {
852 	return minor_hash & osb->osb_dx_mask;
853 }
854 
855 static inline unsigned int ocfs2_dx_dir_hash_idx(struct ocfs2_super *osb,
856 					  struct ocfs2_dx_hinfo *hinfo)
857 {
858 	return __ocfs2_dx_dir_hash_idx(osb, hinfo->minor_hash);
859 }
860 
861 static int ocfs2_dx_dir_lookup(struct inode *inode,
862 			       struct ocfs2_extent_list *el,
863 			       struct ocfs2_dx_hinfo *hinfo,
864 			       u32 *ret_cpos,
865 			       u64 *ret_phys_blkno)
866 {
867 	int ret = 0;
868 	unsigned int cend, uninitialized_var(clen);
869 	u32 uninitialized_var(cpos);
870 	u64 uninitialized_var(blkno);
871 	u32 name_hash = hinfo->major_hash;
872 
873 	ret = ocfs2_dx_dir_lookup_rec(inode, el, name_hash, &cpos, &blkno,
874 				      &clen);
875 	if (ret) {
876 		mlog_errno(ret);
877 		goto out;
878 	}
879 
880 	cend = cpos + clen;
881 	if (name_hash >= cend) {
882 		/* We want the last cluster */
883 		blkno += ocfs2_clusters_to_blocks(inode->i_sb, clen - 1);
884 		cpos += clen - 1;
885 	} else {
886 		blkno += ocfs2_clusters_to_blocks(inode->i_sb,
887 						  name_hash - cpos);
888 		cpos = name_hash;
889 	}
890 
891 	/*
892 	 * We now have the cluster which should hold our entry. To
893 	 * find the exact block from the start of the cluster to
894 	 * search, we take the lower bits of the hash.
895 	 */
896 	blkno += ocfs2_dx_dir_hash_idx(OCFS2_SB(inode->i_sb), hinfo);
897 
898 	if (ret_phys_blkno)
899 		*ret_phys_blkno = blkno;
900 	if (ret_cpos)
901 		*ret_cpos = cpos;
902 
903 out:
904 
905 	return ret;
906 }
907 
908 static int ocfs2_dx_dir_search(const char *name, int namelen,
909 			       struct inode *dir,
910 			       struct ocfs2_dx_root_block *dx_root,
911 			       struct ocfs2_dir_lookup_result *res)
912 {
913 	int ret, i, found;
914 	u64 uninitialized_var(phys);
915 	struct buffer_head *dx_leaf_bh = NULL;
916 	struct ocfs2_dx_leaf *dx_leaf;
917 	struct ocfs2_dx_entry *dx_entry = NULL;
918 	struct buffer_head *dir_ent_bh = NULL;
919 	struct ocfs2_dir_entry *dir_ent = NULL;
920 	struct ocfs2_dx_hinfo *hinfo = &res->dl_hinfo;
921 	struct ocfs2_extent_list *dr_el;
922 	struct ocfs2_dx_entry_list *entry_list;
923 
924 	ocfs2_dx_dir_name_hash(dir, name, namelen, &res->dl_hinfo);
925 
926 	if (ocfs2_dx_root_inline(dx_root)) {
927 		entry_list = &dx_root->dr_entries;
928 		goto search;
929 	}
930 
931 	dr_el = &dx_root->dr_list;
932 
933 	ret = ocfs2_dx_dir_lookup(dir, dr_el, hinfo, NULL, &phys);
934 	if (ret) {
935 		mlog_errno(ret);
936 		goto out;
937 	}
938 
939 	trace_ocfs2_dx_dir_search((unsigned long long)OCFS2_I(dir)->ip_blkno,
940 				  namelen, name, hinfo->major_hash,
941 				  hinfo->minor_hash, (unsigned long long)phys);
942 
943 	ret = ocfs2_read_dx_leaf(dir, phys, &dx_leaf_bh);
944 	if (ret) {
945 		mlog_errno(ret);
946 		goto out;
947 	}
948 
949 	dx_leaf = (struct ocfs2_dx_leaf *) dx_leaf_bh->b_data;
950 
951 	trace_ocfs2_dx_dir_search_leaf_info(
952 			le16_to_cpu(dx_leaf->dl_list.de_num_used),
953 			le16_to_cpu(dx_leaf->dl_list.de_count));
954 
955 	entry_list = &dx_leaf->dl_list;
956 
957 search:
958 	/*
959 	 * Empty leaf is legal, so no need to check for that.
960 	 */
961 	found = 0;
962 	for (i = 0; i < le16_to_cpu(entry_list->de_num_used); i++) {
963 		dx_entry = &entry_list->de_entries[i];
964 
965 		if (hinfo->major_hash != le32_to_cpu(dx_entry->dx_major_hash)
966 		    || hinfo->minor_hash != le32_to_cpu(dx_entry->dx_minor_hash))
967 			continue;
968 
969 		/*
970 		 * Search unindexed leaf block now. We're not
971 		 * guaranteed to find anything.
972 		 */
973 		ret = ocfs2_read_dir_block_direct(dir,
974 					  le64_to_cpu(dx_entry->dx_dirent_blk),
975 					  &dir_ent_bh);
976 		if (ret) {
977 			mlog_errno(ret);
978 			goto out;
979 		}
980 
981 		/*
982 		 * XXX: We should check the unindexed block here,
983 		 * before using it.
984 		 */
985 
986 		found = ocfs2_search_dirblock(dir_ent_bh, dir, name, namelen,
987 					      0, dir_ent_bh->b_data,
988 					      dir->i_sb->s_blocksize, &dir_ent);
989 		if (found == 1)
990 			break;
991 
992 		if (found == -1) {
993 			/* This means we found a bad directory entry. */
994 			ret = -EIO;
995 			mlog_errno(ret);
996 			goto out;
997 		}
998 
999 		brelse(dir_ent_bh);
1000 		dir_ent_bh = NULL;
1001 	}
1002 
1003 	if (found <= 0) {
1004 		ret = -ENOENT;
1005 		goto out;
1006 	}
1007 
1008 	res->dl_leaf_bh = dir_ent_bh;
1009 	res->dl_entry = dir_ent;
1010 	res->dl_dx_leaf_bh = dx_leaf_bh;
1011 	res->dl_dx_entry = dx_entry;
1012 
1013 	ret = 0;
1014 out:
1015 	if (ret) {
1016 		brelse(dx_leaf_bh);
1017 		brelse(dir_ent_bh);
1018 	}
1019 	return ret;
1020 }
1021 
1022 static int ocfs2_find_entry_dx(const char *name, int namelen,
1023 			       struct inode *dir,
1024 			       struct ocfs2_dir_lookup_result *lookup)
1025 {
1026 	int ret;
1027 	struct buffer_head *di_bh = NULL;
1028 	struct ocfs2_dinode *di;
1029 	struct buffer_head *dx_root_bh = NULL;
1030 	struct ocfs2_dx_root_block *dx_root;
1031 
1032 	ret = ocfs2_read_inode_block(dir, &di_bh);
1033 	if (ret) {
1034 		mlog_errno(ret);
1035 		goto out;
1036 	}
1037 
1038 	di = (struct ocfs2_dinode *)di_bh->b_data;
1039 
1040 	ret = ocfs2_read_dx_root(dir, di, &dx_root_bh);
1041 	if (ret) {
1042 		mlog_errno(ret);
1043 		goto out;
1044 	}
1045 	dx_root = (struct ocfs2_dx_root_block *) dx_root_bh->b_data;
1046 
1047 	ret = ocfs2_dx_dir_search(name, namelen, dir, dx_root, lookup);
1048 	if (ret) {
1049 		if (ret != -ENOENT)
1050 			mlog_errno(ret);
1051 		goto out;
1052 	}
1053 
1054 	lookup->dl_dx_root_bh = dx_root_bh;
1055 	dx_root_bh = NULL;
1056 out:
1057 	brelse(di_bh);
1058 	brelse(dx_root_bh);
1059 	return ret;
1060 }
1061 
1062 /*
1063  * Try to find an entry of the provided name within 'dir'.
1064  *
1065  * If nothing was found, -ENOENT is returned. Otherwise, zero is
1066  * returned and the struct 'res' will contain information useful to
1067  * other directory manipulation functions.
1068  *
1069  * Caller can NOT assume anything about the contents of the
1070  * buffer_heads - they are passed back only so that it can be passed
1071  * into any one of the manipulation functions (add entry, delete
1072  * entry, etc). As an example, bh in the extent directory case is a
1073  * data block, in the inline-data case it actually points to an inode,
1074  * in the indexed directory case, multiple buffers are involved.
1075  */
1076 int ocfs2_find_entry(const char *name, int namelen,
1077 		     struct inode *dir, struct ocfs2_dir_lookup_result *lookup)
1078 {
1079 	struct buffer_head *bh;
1080 	struct ocfs2_dir_entry *res_dir = NULL;
1081 
1082 	if (ocfs2_dir_indexed(dir))
1083 		return ocfs2_find_entry_dx(name, namelen, dir, lookup);
1084 
1085 	/*
1086 	 * The unindexed dir code only uses part of the lookup
1087 	 * structure, so there's no reason to push it down further
1088 	 * than this.
1089 	 */
1090 	if (OCFS2_I(dir)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
1091 		bh = ocfs2_find_entry_id(name, namelen, dir, &res_dir);
1092 	else
1093 		bh = ocfs2_find_entry_el(name, namelen, dir, &res_dir);
1094 
1095 	if (bh == NULL)
1096 		return -ENOENT;
1097 
1098 	lookup->dl_leaf_bh = bh;
1099 	lookup->dl_entry = res_dir;
1100 	return 0;
1101 }
1102 
1103 /*
1104  * Update inode number and type of a previously found directory entry.
1105  */
1106 int ocfs2_update_entry(struct inode *dir, handle_t *handle,
1107 		       struct ocfs2_dir_lookup_result *res,
1108 		       struct inode *new_entry_inode)
1109 {
1110 	int ret;
1111 	ocfs2_journal_access_func access = ocfs2_journal_access_db;
1112 	struct ocfs2_dir_entry *de = res->dl_entry;
1113 	struct buffer_head *de_bh = res->dl_leaf_bh;
1114 
1115 	/*
1116 	 * The same code works fine for both inline-data and extent
1117 	 * based directories, so no need to split this up.  The only
1118 	 * difference is the journal_access function.
1119 	 */
1120 
1121 	if (OCFS2_I(dir)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
1122 		access = ocfs2_journal_access_di;
1123 
1124 	ret = access(handle, INODE_CACHE(dir), de_bh,
1125 		     OCFS2_JOURNAL_ACCESS_WRITE);
1126 	if (ret) {
1127 		mlog_errno(ret);
1128 		goto out;
1129 	}
1130 
1131 	de->inode = cpu_to_le64(OCFS2_I(new_entry_inode)->ip_blkno);
1132 	ocfs2_set_de_type(de, new_entry_inode->i_mode);
1133 
1134 	ocfs2_journal_dirty(handle, de_bh);
1135 
1136 out:
1137 	return ret;
1138 }
1139 
1140 /*
1141  * __ocfs2_delete_entry deletes a directory entry by merging it with the
1142  * previous entry
1143  */
1144 static int __ocfs2_delete_entry(handle_t *handle, struct inode *dir,
1145 				struct ocfs2_dir_entry *de_del,
1146 				struct buffer_head *bh, char *first_de,
1147 				unsigned int bytes)
1148 {
1149 	struct ocfs2_dir_entry *de, *pde;
1150 	int i, status = -ENOENT;
1151 	ocfs2_journal_access_func access = ocfs2_journal_access_db;
1152 
1153 	if (OCFS2_I(dir)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
1154 		access = ocfs2_journal_access_di;
1155 
1156 	i = 0;
1157 	pde = NULL;
1158 	de = (struct ocfs2_dir_entry *) first_de;
1159 	while (i < bytes) {
1160 		if (!ocfs2_check_dir_entry(dir, de, bh, i)) {
1161 			status = -EIO;
1162 			mlog_errno(status);
1163 			goto bail;
1164 		}
1165 		if (de == de_del)  {
1166 			status = access(handle, INODE_CACHE(dir), bh,
1167 					OCFS2_JOURNAL_ACCESS_WRITE);
1168 			if (status < 0) {
1169 				status = -EIO;
1170 				mlog_errno(status);
1171 				goto bail;
1172 			}
1173 			if (pde)
1174 				le16_add_cpu(&pde->rec_len,
1175 						le16_to_cpu(de->rec_len));
1176 			de->inode = 0;
1177 			dir->i_version++;
1178 			ocfs2_journal_dirty(handle, bh);
1179 			goto bail;
1180 		}
1181 		i += le16_to_cpu(de->rec_len);
1182 		pde = de;
1183 		de = (struct ocfs2_dir_entry *)((char *)de + le16_to_cpu(de->rec_len));
1184 	}
1185 bail:
1186 	return status;
1187 }
1188 
1189 static unsigned int ocfs2_figure_dirent_hole(struct ocfs2_dir_entry *de)
1190 {
1191 	unsigned int hole;
1192 
1193 	if (le64_to_cpu(de->inode) == 0)
1194 		hole = le16_to_cpu(de->rec_len);
1195 	else
1196 		hole = le16_to_cpu(de->rec_len) -
1197 			OCFS2_DIR_REC_LEN(de->name_len);
1198 
1199 	return hole;
1200 }
1201 
1202 static int ocfs2_find_max_rec_len(struct super_block *sb,
1203 				  struct buffer_head *dirblock_bh)
1204 {
1205 	int size, this_hole, largest_hole = 0;
1206 	char *trailer, *de_buf, *limit, *start = dirblock_bh->b_data;
1207 	struct ocfs2_dir_entry *de;
1208 
1209 	trailer = (char *)ocfs2_trailer_from_bh(dirblock_bh, sb);
1210 	size = ocfs2_dir_trailer_blk_off(sb);
1211 	limit = start + size;
1212 	de_buf = start;
1213 	de = (struct ocfs2_dir_entry *)de_buf;
1214 	do {
1215 		if (de_buf != trailer) {
1216 			this_hole = ocfs2_figure_dirent_hole(de);
1217 			if (this_hole > largest_hole)
1218 				largest_hole = this_hole;
1219 		}
1220 
1221 		de_buf += le16_to_cpu(de->rec_len);
1222 		de = (struct ocfs2_dir_entry *)de_buf;
1223 	} while (de_buf < limit);
1224 
1225 	if (largest_hole >= OCFS2_DIR_MIN_REC_LEN)
1226 		return largest_hole;
1227 	return 0;
1228 }
1229 
1230 static void ocfs2_dx_list_remove_entry(struct ocfs2_dx_entry_list *entry_list,
1231 				       int index)
1232 {
1233 	int num_used = le16_to_cpu(entry_list->de_num_used);
1234 
1235 	if (num_used == 1 || index == (num_used - 1))
1236 		goto clear;
1237 
1238 	memmove(&entry_list->de_entries[index],
1239 		&entry_list->de_entries[index + 1],
1240 		(num_used - index - 1)*sizeof(struct ocfs2_dx_entry));
1241 clear:
1242 	num_used--;
1243 	memset(&entry_list->de_entries[num_used], 0,
1244 	       sizeof(struct ocfs2_dx_entry));
1245 	entry_list->de_num_used = cpu_to_le16(num_used);
1246 }
1247 
1248 static int ocfs2_delete_entry_dx(handle_t *handle, struct inode *dir,
1249 				 struct ocfs2_dir_lookup_result *lookup)
1250 {
1251 	int ret, index, max_rec_len, add_to_free_list = 0;
1252 	struct buffer_head *dx_root_bh = lookup->dl_dx_root_bh;
1253 	struct buffer_head *leaf_bh = lookup->dl_leaf_bh;
1254 	struct ocfs2_dx_leaf *dx_leaf;
1255 	struct ocfs2_dx_entry *dx_entry = lookup->dl_dx_entry;
1256 	struct ocfs2_dir_block_trailer *trailer;
1257 	struct ocfs2_dx_root_block *dx_root;
1258 	struct ocfs2_dx_entry_list *entry_list;
1259 
1260 	/*
1261 	 * This function gets a bit messy because we might have to
1262 	 * modify the root block, regardless of whether the indexed
1263 	 * entries are stored inline.
1264 	 */
1265 
1266 	/*
1267 	 * *Only* set 'entry_list' here, based on where we're looking
1268 	 * for the indexed entries. Later, we might still want to
1269 	 * journal both blocks, based on free list state.
1270 	 */
1271 	dx_root = (struct ocfs2_dx_root_block *)dx_root_bh->b_data;
1272 	if (ocfs2_dx_root_inline(dx_root)) {
1273 		entry_list = &dx_root->dr_entries;
1274 	} else {
1275 		dx_leaf = (struct ocfs2_dx_leaf *) lookup->dl_dx_leaf_bh->b_data;
1276 		entry_list = &dx_leaf->dl_list;
1277 	}
1278 
1279 	/* Neither of these are a disk corruption - that should have
1280 	 * been caught by lookup, before we got here. */
1281 	BUG_ON(le16_to_cpu(entry_list->de_count) <= 0);
1282 	BUG_ON(le16_to_cpu(entry_list->de_num_used) <= 0);
1283 
1284 	index = (char *)dx_entry - (char *)entry_list->de_entries;
1285 	index /= sizeof(*dx_entry);
1286 
1287 	if (index >= le16_to_cpu(entry_list->de_num_used)) {
1288 		mlog(ML_ERROR, "Dir %llu: Bad dx_entry ptr idx %d, (%p, %p)\n",
1289 		     (unsigned long long)OCFS2_I(dir)->ip_blkno, index,
1290 		     entry_list, dx_entry);
1291 		return -EIO;
1292 	}
1293 
1294 	/*
1295 	 * We know that removal of this dirent will leave enough room
1296 	 * for a new one, so add this block to the free list if it
1297 	 * isn't already there.
1298 	 */
1299 	trailer = ocfs2_trailer_from_bh(leaf_bh, dir->i_sb);
1300 	if (trailer->db_free_rec_len == 0)
1301 		add_to_free_list = 1;
1302 
1303 	/*
1304 	 * Add the block holding our index into the journal before
1305 	 * removing the unindexed entry. If we get an error return
1306 	 * from __ocfs2_delete_entry(), then it hasn't removed the
1307 	 * entry yet. Likewise, successful return means we *must*
1308 	 * remove the indexed entry.
1309 	 *
1310 	 * We're also careful to journal the root tree block here as
1311 	 * the entry count needs to be updated. Also, we might be
1312 	 * adding to the start of the free list.
1313 	 */
1314 	ret = ocfs2_journal_access_dr(handle, INODE_CACHE(dir), dx_root_bh,
1315 				      OCFS2_JOURNAL_ACCESS_WRITE);
1316 	if (ret) {
1317 		mlog_errno(ret);
1318 		goto out;
1319 	}
1320 
1321 	if (!ocfs2_dx_root_inline(dx_root)) {
1322 		ret = ocfs2_journal_access_dl(handle, INODE_CACHE(dir),
1323 					      lookup->dl_dx_leaf_bh,
1324 					      OCFS2_JOURNAL_ACCESS_WRITE);
1325 		if (ret) {
1326 			mlog_errno(ret);
1327 			goto out;
1328 		}
1329 	}
1330 
1331 	trace_ocfs2_delete_entry_dx((unsigned long long)OCFS2_I(dir)->ip_blkno,
1332 				    index);
1333 
1334 	ret = __ocfs2_delete_entry(handle, dir, lookup->dl_entry,
1335 				   leaf_bh, leaf_bh->b_data, leaf_bh->b_size);
1336 	if (ret) {
1337 		mlog_errno(ret);
1338 		goto out;
1339 	}
1340 
1341 	max_rec_len = ocfs2_find_max_rec_len(dir->i_sb, leaf_bh);
1342 	trailer->db_free_rec_len = cpu_to_le16(max_rec_len);
1343 	if (add_to_free_list) {
1344 		trailer->db_free_next = dx_root->dr_free_blk;
1345 		dx_root->dr_free_blk = cpu_to_le64(leaf_bh->b_blocknr);
1346 		ocfs2_journal_dirty(handle, dx_root_bh);
1347 	}
1348 
1349 	/* leaf_bh was journal_accessed for us in __ocfs2_delete_entry */
1350 	ocfs2_journal_dirty(handle, leaf_bh);
1351 
1352 	le32_add_cpu(&dx_root->dr_num_entries, -1);
1353 	ocfs2_journal_dirty(handle, dx_root_bh);
1354 
1355 	ocfs2_dx_list_remove_entry(entry_list, index);
1356 
1357 	if (!ocfs2_dx_root_inline(dx_root))
1358 		ocfs2_journal_dirty(handle, lookup->dl_dx_leaf_bh);
1359 
1360 out:
1361 	return ret;
1362 }
1363 
1364 static inline int ocfs2_delete_entry_id(handle_t *handle,
1365 					struct inode *dir,
1366 					struct ocfs2_dir_entry *de_del,
1367 					struct buffer_head *bh)
1368 {
1369 	int ret;
1370 	struct buffer_head *di_bh = NULL;
1371 	struct ocfs2_dinode *di;
1372 	struct ocfs2_inline_data *data;
1373 
1374 	ret = ocfs2_read_inode_block(dir, &di_bh);
1375 	if (ret) {
1376 		mlog_errno(ret);
1377 		goto out;
1378 	}
1379 
1380 	di = (struct ocfs2_dinode *)di_bh->b_data;
1381 	data = &di->id2.i_data;
1382 
1383 	ret = __ocfs2_delete_entry(handle, dir, de_del, bh, data->id_data,
1384 				   i_size_read(dir));
1385 
1386 	brelse(di_bh);
1387 out:
1388 	return ret;
1389 }
1390 
1391 static inline int ocfs2_delete_entry_el(handle_t *handle,
1392 					struct inode *dir,
1393 					struct ocfs2_dir_entry *de_del,
1394 					struct buffer_head *bh)
1395 {
1396 	return __ocfs2_delete_entry(handle, dir, de_del, bh, bh->b_data,
1397 				    bh->b_size);
1398 }
1399 
1400 /*
1401  * Delete a directory entry. Hide the details of directory
1402  * implementation from the caller.
1403  */
1404 int ocfs2_delete_entry(handle_t *handle,
1405 		       struct inode *dir,
1406 		       struct ocfs2_dir_lookup_result *res)
1407 {
1408 	if (ocfs2_dir_indexed(dir))
1409 		return ocfs2_delete_entry_dx(handle, dir, res);
1410 
1411 	if (OCFS2_I(dir)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
1412 		return ocfs2_delete_entry_id(handle, dir, res->dl_entry,
1413 					     res->dl_leaf_bh);
1414 
1415 	return ocfs2_delete_entry_el(handle, dir, res->dl_entry,
1416 				     res->dl_leaf_bh);
1417 }
1418 
1419 /*
1420  * Check whether 'de' has enough room to hold an entry of
1421  * 'new_rec_len' bytes.
1422  */
1423 static inline int ocfs2_dirent_would_fit(struct ocfs2_dir_entry *de,
1424 					 unsigned int new_rec_len)
1425 {
1426 	unsigned int de_really_used;
1427 
1428 	/* Check whether this is an empty record with enough space */
1429 	if (le64_to_cpu(de->inode) == 0 &&
1430 	    le16_to_cpu(de->rec_len) >= new_rec_len)
1431 		return 1;
1432 
1433 	/*
1434 	 * Record might have free space at the end which we can
1435 	 * use.
1436 	 */
1437 	de_really_used = OCFS2_DIR_REC_LEN(de->name_len);
1438 	if (le16_to_cpu(de->rec_len) >= (de_really_used + new_rec_len))
1439 	    return 1;
1440 
1441 	return 0;
1442 }
1443 
1444 static void ocfs2_dx_dir_leaf_insert_tail(struct ocfs2_dx_leaf *dx_leaf,
1445 					  struct ocfs2_dx_entry *dx_new_entry)
1446 {
1447 	int i;
1448 
1449 	i = le16_to_cpu(dx_leaf->dl_list.de_num_used);
1450 	dx_leaf->dl_list.de_entries[i] = *dx_new_entry;
1451 
1452 	le16_add_cpu(&dx_leaf->dl_list.de_num_used, 1);
1453 }
1454 
1455 static void ocfs2_dx_entry_list_insert(struct ocfs2_dx_entry_list *entry_list,
1456 				       struct ocfs2_dx_hinfo *hinfo,
1457 				       u64 dirent_blk)
1458 {
1459 	int i;
1460 	struct ocfs2_dx_entry *dx_entry;
1461 
1462 	i = le16_to_cpu(entry_list->de_num_used);
1463 	dx_entry = &entry_list->de_entries[i];
1464 
1465 	memset(dx_entry, 0, sizeof(*dx_entry));
1466 	dx_entry->dx_major_hash = cpu_to_le32(hinfo->major_hash);
1467 	dx_entry->dx_minor_hash = cpu_to_le32(hinfo->minor_hash);
1468 	dx_entry->dx_dirent_blk = cpu_to_le64(dirent_blk);
1469 
1470 	le16_add_cpu(&entry_list->de_num_used, 1);
1471 }
1472 
1473 static int __ocfs2_dx_dir_leaf_insert(struct inode *dir, handle_t *handle,
1474 				      struct ocfs2_dx_hinfo *hinfo,
1475 				      u64 dirent_blk,
1476 				      struct buffer_head *dx_leaf_bh)
1477 {
1478 	int ret;
1479 	struct ocfs2_dx_leaf *dx_leaf;
1480 
1481 	ret = ocfs2_journal_access_dl(handle, INODE_CACHE(dir), dx_leaf_bh,
1482 				      OCFS2_JOURNAL_ACCESS_WRITE);
1483 	if (ret) {
1484 		mlog_errno(ret);
1485 		goto out;
1486 	}
1487 
1488 	dx_leaf = (struct ocfs2_dx_leaf *)dx_leaf_bh->b_data;
1489 	ocfs2_dx_entry_list_insert(&dx_leaf->dl_list, hinfo, dirent_blk);
1490 	ocfs2_journal_dirty(handle, dx_leaf_bh);
1491 
1492 out:
1493 	return ret;
1494 }
1495 
1496 static void ocfs2_dx_inline_root_insert(struct inode *dir, handle_t *handle,
1497 					struct ocfs2_dx_hinfo *hinfo,
1498 					u64 dirent_blk,
1499 					struct ocfs2_dx_root_block *dx_root)
1500 {
1501 	ocfs2_dx_entry_list_insert(&dx_root->dr_entries, hinfo, dirent_blk);
1502 }
1503 
1504 static int ocfs2_dx_dir_insert(struct inode *dir, handle_t *handle,
1505 			       struct ocfs2_dir_lookup_result *lookup)
1506 {
1507 	int ret = 0;
1508 	struct ocfs2_dx_root_block *dx_root;
1509 	struct buffer_head *dx_root_bh = lookup->dl_dx_root_bh;
1510 
1511 	ret = ocfs2_journal_access_dr(handle, INODE_CACHE(dir), dx_root_bh,
1512 				      OCFS2_JOURNAL_ACCESS_WRITE);
1513 	if (ret) {
1514 		mlog_errno(ret);
1515 		goto out;
1516 	}
1517 
1518 	dx_root = (struct ocfs2_dx_root_block *)lookup->dl_dx_root_bh->b_data;
1519 	if (ocfs2_dx_root_inline(dx_root)) {
1520 		ocfs2_dx_inline_root_insert(dir, handle,
1521 					    &lookup->dl_hinfo,
1522 					    lookup->dl_leaf_bh->b_blocknr,
1523 					    dx_root);
1524 	} else {
1525 		ret = __ocfs2_dx_dir_leaf_insert(dir, handle, &lookup->dl_hinfo,
1526 						 lookup->dl_leaf_bh->b_blocknr,
1527 						 lookup->dl_dx_leaf_bh);
1528 		if (ret)
1529 			goto out;
1530 	}
1531 
1532 	le32_add_cpu(&dx_root->dr_num_entries, 1);
1533 	ocfs2_journal_dirty(handle, dx_root_bh);
1534 
1535 out:
1536 	return ret;
1537 }
1538 
1539 static void ocfs2_remove_block_from_free_list(struct inode *dir,
1540 				       handle_t *handle,
1541 				       struct ocfs2_dir_lookup_result *lookup)
1542 {
1543 	struct ocfs2_dir_block_trailer *trailer, *prev;
1544 	struct ocfs2_dx_root_block *dx_root;
1545 	struct buffer_head *bh;
1546 
1547 	trailer = ocfs2_trailer_from_bh(lookup->dl_leaf_bh, dir->i_sb);
1548 
1549 	if (ocfs2_free_list_at_root(lookup)) {
1550 		bh = lookup->dl_dx_root_bh;
1551 		dx_root = (struct ocfs2_dx_root_block *)bh->b_data;
1552 		dx_root->dr_free_blk = trailer->db_free_next;
1553 	} else {
1554 		bh = lookup->dl_prev_leaf_bh;
1555 		prev = ocfs2_trailer_from_bh(bh, dir->i_sb);
1556 		prev->db_free_next = trailer->db_free_next;
1557 	}
1558 
1559 	trailer->db_free_rec_len = cpu_to_le16(0);
1560 	trailer->db_free_next = cpu_to_le64(0);
1561 
1562 	ocfs2_journal_dirty(handle, bh);
1563 	ocfs2_journal_dirty(handle, lookup->dl_leaf_bh);
1564 }
1565 
1566 /*
1567  * This expects that a journal write has been reserved on
1568  * lookup->dl_prev_leaf_bh or lookup->dl_dx_root_bh
1569  */
1570 static void ocfs2_recalc_free_list(struct inode *dir, handle_t *handle,
1571 				   struct ocfs2_dir_lookup_result *lookup)
1572 {
1573 	int max_rec_len;
1574 	struct ocfs2_dir_block_trailer *trailer;
1575 
1576 	/* Walk dl_leaf_bh to figure out what the new free rec_len is. */
1577 	max_rec_len = ocfs2_find_max_rec_len(dir->i_sb, lookup->dl_leaf_bh);
1578 	if (max_rec_len) {
1579 		/*
1580 		 * There's still room in this block, so no need to remove it
1581 		 * from the free list. In this case, we just want to update
1582 		 * the rec len accounting.
1583 		 */
1584 		trailer = ocfs2_trailer_from_bh(lookup->dl_leaf_bh, dir->i_sb);
1585 		trailer->db_free_rec_len = cpu_to_le16(max_rec_len);
1586 		ocfs2_journal_dirty(handle, lookup->dl_leaf_bh);
1587 	} else {
1588 		ocfs2_remove_block_from_free_list(dir, handle, lookup);
1589 	}
1590 }
1591 
1592 /* we don't always have a dentry for what we want to add, so people
1593  * like orphan dir can call this instead.
1594  *
1595  * The lookup context must have been filled from
1596  * ocfs2_prepare_dir_for_insert.
1597  */
1598 int __ocfs2_add_entry(handle_t *handle,
1599 		      struct inode *dir,
1600 		      const char *name, int namelen,
1601 		      struct inode *inode, u64 blkno,
1602 		      struct buffer_head *parent_fe_bh,
1603 		      struct ocfs2_dir_lookup_result *lookup)
1604 {
1605 	unsigned long offset;
1606 	unsigned short rec_len;
1607 	struct ocfs2_dir_entry *de, *de1;
1608 	struct ocfs2_dinode *di = (struct ocfs2_dinode *)parent_fe_bh->b_data;
1609 	struct super_block *sb = dir->i_sb;
1610 	int retval;
1611 	unsigned int size = sb->s_blocksize;
1612 	struct buffer_head *insert_bh = lookup->dl_leaf_bh;
1613 	char *data_start = insert_bh->b_data;
1614 
1615 	if (!namelen)
1616 		return -EINVAL;
1617 
1618 	if (ocfs2_dir_indexed(dir)) {
1619 		struct buffer_head *bh;
1620 
1621 		/*
1622 		 * An indexed dir may require that we update the free space
1623 		 * list. Reserve a write to the previous node in the list so
1624 		 * that we don't fail later.
1625 		 *
1626 		 * XXX: This can be either a dx_root_block, or an unindexed
1627 		 * directory tree leaf block.
1628 		 */
1629 		if (ocfs2_free_list_at_root(lookup)) {
1630 			bh = lookup->dl_dx_root_bh;
1631 			retval = ocfs2_journal_access_dr(handle,
1632 						 INODE_CACHE(dir), bh,
1633 						 OCFS2_JOURNAL_ACCESS_WRITE);
1634 		} else {
1635 			bh = lookup->dl_prev_leaf_bh;
1636 			retval = ocfs2_journal_access_db(handle,
1637 						 INODE_CACHE(dir), bh,
1638 						 OCFS2_JOURNAL_ACCESS_WRITE);
1639 		}
1640 		if (retval) {
1641 			mlog_errno(retval);
1642 			return retval;
1643 		}
1644 	} else if (OCFS2_I(dir)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
1645 		data_start = di->id2.i_data.id_data;
1646 		size = i_size_read(dir);
1647 
1648 		BUG_ON(insert_bh != parent_fe_bh);
1649 	}
1650 
1651 	rec_len = OCFS2_DIR_REC_LEN(namelen);
1652 	offset = 0;
1653 	de = (struct ocfs2_dir_entry *) data_start;
1654 	while (1) {
1655 		BUG_ON((char *)de >= (size + data_start));
1656 
1657 		/* These checks should've already been passed by the
1658 		 * prepare function, but I guess we can leave them
1659 		 * here anyway. */
1660 		if (!ocfs2_check_dir_entry(dir, de, insert_bh, offset)) {
1661 			retval = -ENOENT;
1662 			goto bail;
1663 		}
1664 		if (ocfs2_match(namelen, name, de)) {
1665 			retval = -EEXIST;
1666 			goto bail;
1667 		}
1668 
1669 		/* We're guaranteed that we should have space, so we
1670 		 * can't possibly have hit the trailer...right? */
1671 		mlog_bug_on_msg(ocfs2_skip_dir_trailer(dir, de, offset, size),
1672 				"Hit dir trailer trying to insert %.*s "
1673 			        "(namelen %d) into directory %llu.  "
1674 				"offset is %lu, trailer offset is %d\n",
1675 				namelen, name, namelen,
1676 				(unsigned long long)parent_fe_bh->b_blocknr,
1677 				offset, ocfs2_dir_trailer_blk_off(dir->i_sb));
1678 
1679 		if (ocfs2_dirent_would_fit(de, rec_len)) {
1680 			dir->i_mtime = dir->i_ctime = current_time(dir);
1681 			retval = ocfs2_mark_inode_dirty(handle, dir, parent_fe_bh);
1682 			if (retval < 0) {
1683 				mlog_errno(retval);
1684 				goto bail;
1685 			}
1686 
1687 			if (insert_bh == parent_fe_bh)
1688 				retval = ocfs2_journal_access_di(handle,
1689 								 INODE_CACHE(dir),
1690 								 insert_bh,
1691 								 OCFS2_JOURNAL_ACCESS_WRITE);
1692 			else {
1693 				retval = ocfs2_journal_access_db(handle,
1694 								 INODE_CACHE(dir),
1695 								 insert_bh,
1696 					      OCFS2_JOURNAL_ACCESS_WRITE);
1697 
1698 				if (!retval && ocfs2_dir_indexed(dir))
1699 					retval = ocfs2_dx_dir_insert(dir,
1700 								handle,
1701 								lookup);
1702 			}
1703 
1704 			if (retval) {
1705 				mlog_errno(retval);
1706 				goto bail;
1707 			}
1708 
1709 			/* By now the buffer is marked for journaling */
1710 			offset += le16_to_cpu(de->rec_len);
1711 			if (le64_to_cpu(de->inode)) {
1712 				de1 = (struct ocfs2_dir_entry *)((char *) de +
1713 					OCFS2_DIR_REC_LEN(de->name_len));
1714 				de1->rec_len =
1715 					cpu_to_le16(le16_to_cpu(de->rec_len) -
1716 					OCFS2_DIR_REC_LEN(de->name_len));
1717 				de->rec_len = cpu_to_le16(OCFS2_DIR_REC_LEN(de->name_len));
1718 				de = de1;
1719 			}
1720 			de->file_type = OCFS2_FT_UNKNOWN;
1721 			if (blkno) {
1722 				de->inode = cpu_to_le64(blkno);
1723 				ocfs2_set_de_type(de, inode->i_mode);
1724 			} else
1725 				de->inode = 0;
1726 			de->name_len = namelen;
1727 			memcpy(de->name, name, namelen);
1728 
1729 			if (ocfs2_dir_indexed(dir))
1730 				ocfs2_recalc_free_list(dir, handle, lookup);
1731 
1732 			dir->i_version++;
1733 			ocfs2_journal_dirty(handle, insert_bh);
1734 			retval = 0;
1735 			goto bail;
1736 		}
1737 
1738 		offset += le16_to_cpu(de->rec_len);
1739 		de = (struct ocfs2_dir_entry *) ((char *) de + le16_to_cpu(de->rec_len));
1740 	}
1741 
1742 	/* when you think about it, the assert above should prevent us
1743 	 * from ever getting here. */
1744 	retval = -ENOSPC;
1745 bail:
1746 	if (retval)
1747 		mlog_errno(retval);
1748 
1749 	return retval;
1750 }
1751 
1752 static int ocfs2_dir_foreach_blk_id(struct inode *inode,
1753 				    u64 *f_version,
1754 				    struct dir_context *ctx)
1755 {
1756 	int ret, i;
1757 	unsigned long offset = ctx->pos;
1758 	struct buffer_head *di_bh = NULL;
1759 	struct ocfs2_dinode *di;
1760 	struct ocfs2_inline_data *data;
1761 	struct ocfs2_dir_entry *de;
1762 
1763 	ret = ocfs2_read_inode_block(inode, &di_bh);
1764 	if (ret) {
1765 		mlog(ML_ERROR, "Unable to read inode block for dir %llu\n",
1766 		     (unsigned long long)OCFS2_I(inode)->ip_blkno);
1767 		goto out;
1768 	}
1769 
1770 	di = (struct ocfs2_dinode *)di_bh->b_data;
1771 	data = &di->id2.i_data;
1772 
1773 	while (ctx->pos < i_size_read(inode)) {
1774 		/* If the dir block has changed since the last call to
1775 		 * readdir(2), then we might be pointing to an invalid
1776 		 * dirent right now.  Scan from the start of the block
1777 		 * to make sure. */
1778 		if (*f_version != inode->i_version) {
1779 			for (i = 0; i < i_size_read(inode) && i < offset; ) {
1780 				de = (struct ocfs2_dir_entry *)
1781 					(data->id_data + i);
1782 				/* It's too expensive to do a full
1783 				 * dirent test each time round this
1784 				 * loop, but we do have to test at
1785 				 * least that it is non-zero.  A
1786 				 * failure will be detected in the
1787 				 * dirent test below. */
1788 				if (le16_to_cpu(de->rec_len) <
1789 				    OCFS2_DIR_REC_LEN(1))
1790 					break;
1791 				i += le16_to_cpu(de->rec_len);
1792 			}
1793 			ctx->pos = offset = i;
1794 			*f_version = inode->i_version;
1795 		}
1796 
1797 		de = (struct ocfs2_dir_entry *) (data->id_data + ctx->pos);
1798 		if (!ocfs2_check_dir_entry(inode, de, di_bh, ctx->pos)) {
1799 			/* On error, skip the f_pos to the end. */
1800 			ctx->pos = i_size_read(inode);
1801 			break;
1802 		}
1803 		offset += le16_to_cpu(de->rec_len);
1804 		if (le64_to_cpu(de->inode)) {
1805 			unsigned char d_type = DT_UNKNOWN;
1806 
1807 			if (de->file_type < OCFS2_FT_MAX)
1808 				d_type = ocfs2_filetype_table[de->file_type];
1809 
1810 			if (!dir_emit(ctx, de->name, de->name_len,
1811 				      le64_to_cpu(de->inode), d_type))
1812 				goto out;
1813 		}
1814 		ctx->pos += le16_to_cpu(de->rec_len);
1815 	}
1816 out:
1817 	brelse(di_bh);
1818 	return 0;
1819 }
1820 
1821 /*
1822  * NOTE: This function can be called against unindexed directories,
1823  * and indexed ones.
1824  */
1825 static int ocfs2_dir_foreach_blk_el(struct inode *inode,
1826 				    u64 *f_version,
1827 				    struct dir_context *ctx,
1828 				    bool persist)
1829 {
1830 	unsigned long offset, blk, last_ra_blk = 0;
1831 	int i;
1832 	struct buffer_head * bh, * tmp;
1833 	struct ocfs2_dir_entry * de;
1834 	struct super_block * sb = inode->i_sb;
1835 	unsigned int ra_sectors = 16;
1836 	int stored = 0;
1837 
1838 	bh = NULL;
1839 
1840 	offset = ctx->pos & (sb->s_blocksize - 1);
1841 
1842 	while (ctx->pos < i_size_read(inode)) {
1843 		blk = ctx->pos >> sb->s_blocksize_bits;
1844 		if (ocfs2_read_dir_block(inode, blk, &bh, 0)) {
1845 			/* Skip the corrupt dirblock and keep trying */
1846 			ctx->pos += sb->s_blocksize - offset;
1847 			continue;
1848 		}
1849 
1850 		/* The idea here is to begin with 8k read-ahead and to stay
1851 		 * 4k ahead of our current position.
1852 		 *
1853 		 * TODO: Use the pagecache for this. We just need to
1854 		 * make sure it's cluster-safe... */
1855 		if (!last_ra_blk
1856 		    || (((last_ra_blk - blk) << 9) <= (ra_sectors / 2))) {
1857 			for (i = ra_sectors >> (sb->s_blocksize_bits - 9);
1858 			     i > 0; i--) {
1859 				tmp = NULL;
1860 				if (!ocfs2_read_dir_block(inode, ++blk, &tmp,
1861 							  OCFS2_BH_READAHEAD))
1862 					brelse(tmp);
1863 			}
1864 			last_ra_blk = blk;
1865 			ra_sectors = 8;
1866 		}
1867 
1868 		/* If the dir block has changed since the last call to
1869 		 * readdir(2), then we might be pointing to an invalid
1870 		 * dirent right now.  Scan from the start of the block
1871 		 * to make sure. */
1872 		if (*f_version != inode->i_version) {
1873 			for (i = 0; i < sb->s_blocksize && i < offset; ) {
1874 				de = (struct ocfs2_dir_entry *) (bh->b_data + i);
1875 				/* It's too expensive to do a full
1876 				 * dirent test each time round this
1877 				 * loop, but we do have to test at
1878 				 * least that it is non-zero.  A
1879 				 * failure will be detected in the
1880 				 * dirent test below. */
1881 				if (le16_to_cpu(de->rec_len) <
1882 				    OCFS2_DIR_REC_LEN(1))
1883 					break;
1884 				i += le16_to_cpu(de->rec_len);
1885 			}
1886 			offset = i;
1887 			ctx->pos = (ctx->pos & ~(sb->s_blocksize - 1))
1888 				| offset;
1889 			*f_version = inode->i_version;
1890 		}
1891 
1892 		while (ctx->pos < i_size_read(inode)
1893 		       && offset < sb->s_blocksize) {
1894 			de = (struct ocfs2_dir_entry *) (bh->b_data + offset);
1895 			if (!ocfs2_check_dir_entry(inode, de, bh, offset)) {
1896 				/* On error, skip the f_pos to the
1897 				   next block. */
1898 				ctx->pos = (ctx->pos | (sb->s_blocksize - 1)) + 1;
1899 				brelse(bh);
1900 				continue;
1901 			}
1902 			if (le64_to_cpu(de->inode)) {
1903 				unsigned char d_type = DT_UNKNOWN;
1904 
1905 				if (de->file_type < OCFS2_FT_MAX)
1906 					d_type = ocfs2_filetype_table[de->file_type];
1907 				if (!dir_emit(ctx, de->name,
1908 						de->name_len,
1909 						le64_to_cpu(de->inode),
1910 						d_type)) {
1911 					brelse(bh);
1912 					return 0;
1913 				}
1914 				stored++;
1915 			}
1916 			offset += le16_to_cpu(de->rec_len);
1917 			ctx->pos += le16_to_cpu(de->rec_len);
1918 		}
1919 		offset = 0;
1920 		brelse(bh);
1921 		bh = NULL;
1922 		if (!persist && stored)
1923 			break;
1924 	}
1925 	return 0;
1926 }
1927 
1928 static int ocfs2_dir_foreach_blk(struct inode *inode, u64 *f_version,
1929 				 struct dir_context *ctx,
1930 				 bool persist)
1931 {
1932 	if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
1933 		return ocfs2_dir_foreach_blk_id(inode, f_version, ctx);
1934 	return ocfs2_dir_foreach_blk_el(inode, f_version, ctx, persist);
1935 }
1936 
1937 /*
1938  * This is intended to be called from inside other kernel functions,
1939  * so we fake some arguments.
1940  */
1941 int ocfs2_dir_foreach(struct inode *inode, struct dir_context *ctx)
1942 {
1943 	u64 version = inode->i_version;
1944 	ocfs2_dir_foreach_blk(inode, &version, ctx, true);
1945 	return 0;
1946 }
1947 
1948 /*
1949  * ocfs2_readdir()
1950  *
1951  */
1952 int ocfs2_readdir(struct file *file, struct dir_context *ctx)
1953 {
1954 	int error = 0;
1955 	struct inode *inode = file_inode(file);
1956 	int lock_level = 0;
1957 
1958 	trace_ocfs2_readdir((unsigned long long)OCFS2_I(inode)->ip_blkno);
1959 
1960 	error = ocfs2_inode_lock_atime(inode, file->f_path.mnt, &lock_level);
1961 	if (lock_level && error >= 0) {
1962 		/* We release EX lock which used to update atime
1963 		 * and get PR lock again to reduce contention
1964 		 * on commonly accessed directories. */
1965 		ocfs2_inode_unlock(inode, 1);
1966 		lock_level = 0;
1967 		error = ocfs2_inode_lock(inode, NULL, 0);
1968 	}
1969 	if (error < 0) {
1970 		if (error != -ENOENT)
1971 			mlog_errno(error);
1972 		/* we haven't got any yet, so propagate the error. */
1973 		goto bail_nolock;
1974 	}
1975 
1976 	error = ocfs2_dir_foreach_blk(inode, &file->f_version, ctx, false);
1977 
1978 	ocfs2_inode_unlock(inode, lock_level);
1979 	if (error)
1980 		mlog_errno(error);
1981 
1982 bail_nolock:
1983 
1984 	return error;
1985 }
1986 
1987 /*
1988  * NOTE: this should always be called with parent dir i_mutex taken.
1989  */
1990 int ocfs2_find_files_on_disk(const char *name,
1991 			     int namelen,
1992 			     u64 *blkno,
1993 			     struct inode *inode,
1994 			     struct ocfs2_dir_lookup_result *lookup)
1995 {
1996 	int status = -ENOENT;
1997 
1998 	trace_ocfs2_find_files_on_disk(namelen, name, blkno,
1999 				(unsigned long long)OCFS2_I(inode)->ip_blkno);
2000 
2001 	status = ocfs2_find_entry(name, namelen, inode, lookup);
2002 	if (status)
2003 		goto leave;
2004 
2005 	*blkno = le64_to_cpu(lookup->dl_entry->inode);
2006 
2007 	status = 0;
2008 leave:
2009 
2010 	return status;
2011 }
2012 
2013 /*
2014  * Convenience function for callers which just want the block number
2015  * mapped to a name and don't require the full dirent info, etc.
2016  */
2017 int ocfs2_lookup_ino_from_name(struct inode *dir, const char *name,
2018 			       int namelen, u64 *blkno)
2019 {
2020 	int ret;
2021 	struct ocfs2_dir_lookup_result lookup = { NULL, };
2022 
2023 	ret = ocfs2_find_files_on_disk(name, namelen, blkno, dir, &lookup);
2024 	ocfs2_free_dir_lookup_result(&lookup);
2025 
2026 	return ret;
2027 }
2028 
2029 /* Check for a name within a directory.
2030  *
2031  * Return 0 if the name does not exist
2032  * Return -EEXIST if the directory contains the name
2033  *
2034  * Callers should have i_mutex + a cluster lock on dir
2035  */
2036 int ocfs2_check_dir_for_entry(struct inode *dir,
2037 			      const char *name,
2038 			      int namelen)
2039 {
2040 	int ret = 0;
2041 	struct ocfs2_dir_lookup_result lookup = { NULL, };
2042 
2043 	trace_ocfs2_check_dir_for_entry(
2044 		(unsigned long long)OCFS2_I(dir)->ip_blkno, namelen, name);
2045 
2046 	if (ocfs2_find_entry(name, namelen, dir, &lookup) == 0) {
2047 		ret = -EEXIST;
2048 		mlog_errno(ret);
2049 	}
2050 
2051 	ocfs2_free_dir_lookup_result(&lookup);
2052 
2053 	return ret;
2054 }
2055 
2056 struct ocfs2_empty_dir_priv {
2057 	struct dir_context ctx;
2058 	unsigned seen_dot;
2059 	unsigned seen_dot_dot;
2060 	unsigned seen_other;
2061 	unsigned dx_dir;
2062 };
2063 static int ocfs2_empty_dir_filldir(struct dir_context *ctx, const char *name,
2064 				   int name_len, loff_t pos, u64 ino,
2065 				   unsigned type)
2066 {
2067 	struct ocfs2_empty_dir_priv *p =
2068 		container_of(ctx, struct ocfs2_empty_dir_priv, ctx);
2069 
2070 	/*
2071 	 * Check the positions of "." and ".." records to be sure
2072 	 * they're in the correct place.
2073 	 *
2074 	 * Indexed directories don't need to proceed past the first
2075 	 * two entries, so we end the scan after seeing '..'. Despite
2076 	 * that, we allow the scan to proceed In the event that we
2077 	 * have a corrupted indexed directory (no dot or dot dot
2078 	 * entries). This allows us to double check for existing
2079 	 * entries which might not have been found in the index.
2080 	 */
2081 	if (name_len == 1 && !strncmp(".", name, 1) && pos == 0) {
2082 		p->seen_dot = 1;
2083 		return 0;
2084 	}
2085 
2086 	if (name_len == 2 && !strncmp("..", name, 2) &&
2087 	    pos == OCFS2_DIR_REC_LEN(1)) {
2088 		p->seen_dot_dot = 1;
2089 
2090 		if (p->dx_dir && p->seen_dot)
2091 			return 1;
2092 
2093 		return 0;
2094 	}
2095 
2096 	p->seen_other = 1;
2097 	return 1;
2098 }
2099 
2100 static int ocfs2_empty_dir_dx(struct inode *inode,
2101 			      struct ocfs2_empty_dir_priv *priv)
2102 {
2103 	int ret;
2104 	struct buffer_head *di_bh = NULL;
2105 	struct buffer_head *dx_root_bh = NULL;
2106 	struct ocfs2_dinode *di;
2107 	struct ocfs2_dx_root_block *dx_root;
2108 
2109 	priv->dx_dir = 1;
2110 
2111 	ret = ocfs2_read_inode_block(inode, &di_bh);
2112 	if (ret) {
2113 		mlog_errno(ret);
2114 		goto out;
2115 	}
2116 	di = (struct ocfs2_dinode *)di_bh->b_data;
2117 
2118 	ret = ocfs2_read_dx_root(inode, di, &dx_root_bh);
2119 	if (ret) {
2120 		mlog_errno(ret);
2121 		goto out;
2122 	}
2123 	dx_root = (struct ocfs2_dx_root_block *)dx_root_bh->b_data;
2124 
2125 	if (le32_to_cpu(dx_root->dr_num_entries) != 2)
2126 		priv->seen_other = 1;
2127 
2128 out:
2129 	brelse(di_bh);
2130 	brelse(dx_root_bh);
2131 	return ret;
2132 }
2133 
2134 /*
2135  * routine to check that the specified directory is empty (for rmdir)
2136  *
2137  * Returns 1 if dir is empty, zero otherwise.
2138  *
2139  * XXX: This is a performance problem for unindexed directories.
2140  */
2141 int ocfs2_empty_dir(struct inode *inode)
2142 {
2143 	int ret;
2144 	struct ocfs2_empty_dir_priv priv = {
2145 		.ctx.actor = ocfs2_empty_dir_filldir,
2146 	};
2147 
2148 	if (ocfs2_dir_indexed(inode)) {
2149 		ret = ocfs2_empty_dir_dx(inode, &priv);
2150 		if (ret)
2151 			mlog_errno(ret);
2152 		/*
2153 		 * We still run ocfs2_dir_foreach to get the checks
2154 		 * for "." and "..".
2155 		 */
2156 	}
2157 
2158 	ret = ocfs2_dir_foreach(inode, &priv.ctx);
2159 	if (ret)
2160 		mlog_errno(ret);
2161 
2162 	if (!priv.seen_dot || !priv.seen_dot_dot) {
2163 		mlog(ML_ERROR, "bad directory (dir #%llu) - no `.' or `..'\n",
2164 		     (unsigned long long)OCFS2_I(inode)->ip_blkno);
2165 		/*
2166 		 * XXX: Is it really safe to allow an unlink to continue?
2167 		 */
2168 		return 1;
2169 	}
2170 
2171 	return !priv.seen_other;
2172 }
2173 
2174 /*
2175  * Fills "." and ".." dirents in a new directory block. Returns dirent for
2176  * "..", which might be used during creation of a directory with a trailing
2177  * header. It is otherwise safe to ignore the return code.
2178  */
2179 static struct ocfs2_dir_entry *ocfs2_fill_initial_dirents(struct inode *inode,
2180 							  struct inode *parent,
2181 							  char *start,
2182 							  unsigned int size)
2183 {
2184 	struct ocfs2_dir_entry *de = (struct ocfs2_dir_entry *)start;
2185 
2186 	de->inode = cpu_to_le64(OCFS2_I(inode)->ip_blkno);
2187 	de->name_len = 1;
2188 	de->rec_len =
2189 		cpu_to_le16(OCFS2_DIR_REC_LEN(de->name_len));
2190 	strcpy(de->name, ".");
2191 	ocfs2_set_de_type(de, S_IFDIR);
2192 
2193 	de = (struct ocfs2_dir_entry *) ((char *)de + le16_to_cpu(de->rec_len));
2194 	de->inode = cpu_to_le64(OCFS2_I(parent)->ip_blkno);
2195 	de->rec_len = cpu_to_le16(size - OCFS2_DIR_REC_LEN(1));
2196 	de->name_len = 2;
2197 	strcpy(de->name, "..");
2198 	ocfs2_set_de_type(de, S_IFDIR);
2199 
2200 	return de;
2201 }
2202 
2203 /*
2204  * This works together with code in ocfs2_mknod_locked() which sets
2205  * the inline-data flag and initializes the inline-data section.
2206  */
2207 static int ocfs2_fill_new_dir_id(struct ocfs2_super *osb,
2208 				 handle_t *handle,
2209 				 struct inode *parent,
2210 				 struct inode *inode,
2211 				 struct buffer_head *di_bh)
2212 {
2213 	int ret;
2214 	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
2215 	struct ocfs2_inline_data *data = &di->id2.i_data;
2216 	unsigned int size = le16_to_cpu(data->id_count);
2217 
2218 	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
2219 				      OCFS2_JOURNAL_ACCESS_WRITE);
2220 	if (ret) {
2221 		mlog_errno(ret);
2222 		goto out;
2223 	}
2224 
2225 	ocfs2_fill_initial_dirents(inode, parent, data->id_data, size);
2226 	ocfs2_journal_dirty(handle, di_bh);
2227 
2228 	i_size_write(inode, size);
2229 	set_nlink(inode, 2);
2230 	inode->i_blocks = ocfs2_inode_sector_count(inode);
2231 
2232 	ret = ocfs2_mark_inode_dirty(handle, inode, di_bh);
2233 	if (ret < 0)
2234 		mlog_errno(ret);
2235 
2236 out:
2237 	return ret;
2238 }
2239 
2240 static int ocfs2_fill_new_dir_el(struct ocfs2_super *osb,
2241 				 handle_t *handle,
2242 				 struct inode *parent,
2243 				 struct inode *inode,
2244 				 struct buffer_head *fe_bh,
2245 				 struct ocfs2_alloc_context *data_ac,
2246 				 struct buffer_head **ret_new_bh)
2247 {
2248 	int status;
2249 	unsigned int size = osb->sb->s_blocksize;
2250 	struct buffer_head *new_bh = NULL;
2251 	struct ocfs2_dir_entry *de;
2252 
2253 	if (ocfs2_new_dir_wants_trailer(inode))
2254 		size = ocfs2_dir_trailer_blk_off(parent->i_sb);
2255 
2256 	status = ocfs2_do_extend_dir(osb->sb, handle, inode, fe_bh,
2257 				     data_ac, NULL, &new_bh);
2258 	if (status < 0) {
2259 		mlog_errno(status);
2260 		goto bail;
2261 	}
2262 
2263 	ocfs2_set_new_buffer_uptodate(INODE_CACHE(inode), new_bh);
2264 
2265 	status = ocfs2_journal_access_db(handle, INODE_CACHE(inode), new_bh,
2266 					 OCFS2_JOURNAL_ACCESS_CREATE);
2267 	if (status < 0) {
2268 		mlog_errno(status);
2269 		goto bail;
2270 	}
2271 	memset(new_bh->b_data, 0, osb->sb->s_blocksize);
2272 
2273 	de = ocfs2_fill_initial_dirents(inode, parent, new_bh->b_data, size);
2274 	if (ocfs2_new_dir_wants_trailer(inode)) {
2275 		int size = le16_to_cpu(de->rec_len);
2276 
2277 		/*
2278 		 * Figure out the size of the hole left over after
2279 		 * insertion of '.' and '..'. The trailer wants this
2280 		 * information.
2281 		 */
2282 		size -= OCFS2_DIR_REC_LEN(2);
2283 		size -= sizeof(struct ocfs2_dir_block_trailer);
2284 
2285 		ocfs2_init_dir_trailer(inode, new_bh, size);
2286 	}
2287 
2288 	ocfs2_journal_dirty(handle, new_bh);
2289 
2290 	i_size_write(inode, inode->i_sb->s_blocksize);
2291 	set_nlink(inode, 2);
2292 	inode->i_blocks = ocfs2_inode_sector_count(inode);
2293 	status = ocfs2_mark_inode_dirty(handle, inode, fe_bh);
2294 	if (status < 0) {
2295 		mlog_errno(status);
2296 		goto bail;
2297 	}
2298 
2299 	status = 0;
2300 	if (ret_new_bh) {
2301 		*ret_new_bh = new_bh;
2302 		new_bh = NULL;
2303 	}
2304 bail:
2305 	brelse(new_bh);
2306 
2307 	return status;
2308 }
2309 
2310 static int ocfs2_dx_dir_attach_index(struct ocfs2_super *osb,
2311 				     handle_t *handle, struct inode *dir,
2312 				     struct buffer_head *di_bh,
2313 				     struct buffer_head *dirdata_bh,
2314 				     struct ocfs2_alloc_context *meta_ac,
2315 				     int dx_inline, u32 num_entries,
2316 				     struct buffer_head **ret_dx_root_bh)
2317 {
2318 	int ret;
2319 	struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
2320 	u16 dr_suballoc_bit;
2321 	u64 suballoc_loc, dr_blkno;
2322 	unsigned int num_bits;
2323 	struct buffer_head *dx_root_bh = NULL;
2324 	struct ocfs2_dx_root_block *dx_root;
2325 	struct ocfs2_dir_block_trailer *trailer =
2326 		ocfs2_trailer_from_bh(dirdata_bh, dir->i_sb);
2327 
2328 	ret = ocfs2_claim_metadata(handle, meta_ac, 1, &suballoc_loc,
2329 				   &dr_suballoc_bit, &num_bits, &dr_blkno);
2330 	if (ret) {
2331 		mlog_errno(ret);
2332 		goto out;
2333 	}
2334 
2335 	trace_ocfs2_dx_dir_attach_index(
2336 				(unsigned long long)OCFS2_I(dir)->ip_blkno,
2337 				(unsigned long long)dr_blkno);
2338 
2339 	dx_root_bh = sb_getblk(osb->sb, dr_blkno);
2340 	if (dx_root_bh == NULL) {
2341 		ret = -ENOMEM;
2342 		goto out;
2343 	}
2344 	ocfs2_set_new_buffer_uptodate(INODE_CACHE(dir), dx_root_bh);
2345 
2346 	ret = ocfs2_journal_access_dr(handle, INODE_CACHE(dir), dx_root_bh,
2347 				      OCFS2_JOURNAL_ACCESS_CREATE);
2348 	if (ret < 0) {
2349 		mlog_errno(ret);
2350 		goto out;
2351 	}
2352 
2353 	dx_root = (struct ocfs2_dx_root_block *)dx_root_bh->b_data;
2354 	memset(dx_root, 0, osb->sb->s_blocksize);
2355 	strcpy(dx_root->dr_signature, OCFS2_DX_ROOT_SIGNATURE);
2356 	dx_root->dr_suballoc_slot = cpu_to_le16(meta_ac->ac_alloc_slot);
2357 	dx_root->dr_suballoc_loc = cpu_to_le64(suballoc_loc);
2358 	dx_root->dr_suballoc_bit = cpu_to_le16(dr_suballoc_bit);
2359 	dx_root->dr_fs_generation = cpu_to_le32(osb->fs_generation);
2360 	dx_root->dr_blkno = cpu_to_le64(dr_blkno);
2361 	dx_root->dr_dir_blkno = cpu_to_le64(OCFS2_I(dir)->ip_blkno);
2362 	dx_root->dr_num_entries = cpu_to_le32(num_entries);
2363 	if (le16_to_cpu(trailer->db_free_rec_len))
2364 		dx_root->dr_free_blk = cpu_to_le64(dirdata_bh->b_blocknr);
2365 	else
2366 		dx_root->dr_free_blk = cpu_to_le64(0);
2367 
2368 	if (dx_inline) {
2369 		dx_root->dr_flags |= OCFS2_DX_FLAG_INLINE;
2370 		dx_root->dr_entries.de_count =
2371 			cpu_to_le16(ocfs2_dx_entries_per_root(osb->sb));
2372 	} else {
2373 		dx_root->dr_list.l_count =
2374 			cpu_to_le16(ocfs2_extent_recs_per_dx_root(osb->sb));
2375 	}
2376 	ocfs2_journal_dirty(handle, dx_root_bh);
2377 
2378 	ret = ocfs2_journal_access_di(handle, INODE_CACHE(dir), di_bh,
2379 				      OCFS2_JOURNAL_ACCESS_CREATE);
2380 	if (ret) {
2381 		mlog_errno(ret);
2382 		goto out;
2383 	}
2384 
2385 	di->i_dx_root = cpu_to_le64(dr_blkno);
2386 
2387 	spin_lock(&OCFS2_I(dir)->ip_lock);
2388 	OCFS2_I(dir)->ip_dyn_features |= OCFS2_INDEXED_DIR_FL;
2389 	di->i_dyn_features = cpu_to_le16(OCFS2_I(dir)->ip_dyn_features);
2390 	spin_unlock(&OCFS2_I(dir)->ip_lock);
2391 
2392 	ocfs2_journal_dirty(handle, di_bh);
2393 
2394 	*ret_dx_root_bh = dx_root_bh;
2395 	dx_root_bh = NULL;
2396 
2397 out:
2398 	brelse(dx_root_bh);
2399 	return ret;
2400 }
2401 
2402 static int ocfs2_dx_dir_format_cluster(struct ocfs2_super *osb,
2403 				       handle_t *handle, struct inode *dir,
2404 				       struct buffer_head **dx_leaves,
2405 				       int num_dx_leaves, u64 start_blk)
2406 {
2407 	int ret, i;
2408 	struct ocfs2_dx_leaf *dx_leaf;
2409 	struct buffer_head *bh;
2410 
2411 	for (i = 0; i < num_dx_leaves; i++) {
2412 		bh = sb_getblk(osb->sb, start_blk + i);
2413 		if (bh == NULL) {
2414 			ret = -ENOMEM;
2415 			goto out;
2416 		}
2417 		dx_leaves[i] = bh;
2418 
2419 		ocfs2_set_new_buffer_uptodate(INODE_CACHE(dir), bh);
2420 
2421 		ret = ocfs2_journal_access_dl(handle, INODE_CACHE(dir), bh,
2422 					      OCFS2_JOURNAL_ACCESS_CREATE);
2423 		if (ret < 0) {
2424 			mlog_errno(ret);
2425 			goto out;
2426 		}
2427 
2428 		dx_leaf = (struct ocfs2_dx_leaf *) bh->b_data;
2429 
2430 		memset(dx_leaf, 0, osb->sb->s_blocksize);
2431 		strcpy(dx_leaf->dl_signature, OCFS2_DX_LEAF_SIGNATURE);
2432 		dx_leaf->dl_fs_generation = cpu_to_le32(osb->fs_generation);
2433 		dx_leaf->dl_blkno = cpu_to_le64(bh->b_blocknr);
2434 		dx_leaf->dl_list.de_count =
2435 			cpu_to_le16(ocfs2_dx_entries_per_leaf(osb->sb));
2436 
2437 		trace_ocfs2_dx_dir_format_cluster(
2438 				(unsigned long long)OCFS2_I(dir)->ip_blkno,
2439 				(unsigned long long)bh->b_blocknr,
2440 				le16_to_cpu(dx_leaf->dl_list.de_count));
2441 
2442 		ocfs2_journal_dirty(handle, bh);
2443 	}
2444 
2445 	ret = 0;
2446 out:
2447 	return ret;
2448 }
2449 
2450 /*
2451  * Allocates and formats a new cluster for use in an indexed dir
2452  * leaf. This version will not do the extent insert, so that it can be
2453  * used by operations which need careful ordering.
2454  */
2455 static int __ocfs2_dx_dir_new_cluster(struct inode *dir,
2456 				      u32 cpos, handle_t *handle,
2457 				      struct ocfs2_alloc_context *data_ac,
2458 				      struct buffer_head **dx_leaves,
2459 				      int num_dx_leaves, u64 *ret_phys_blkno)
2460 {
2461 	int ret;
2462 	u32 phys, num;
2463 	u64 phys_blkno;
2464 	struct ocfs2_super *osb = OCFS2_SB(dir->i_sb);
2465 
2466 	/*
2467 	 * XXX: For create, this should claim cluster for the index
2468 	 * *before* the unindexed insert so that we have a better
2469 	 * chance of contiguousness as the directory grows in number
2470 	 * of entries.
2471 	 */
2472 	ret = __ocfs2_claim_clusters(handle, data_ac, 1, 1, &phys, &num);
2473 	if (ret) {
2474 		mlog_errno(ret);
2475 		goto out;
2476 	}
2477 
2478 	/*
2479 	 * Format the new cluster first. That way, we're inserting
2480 	 * valid data.
2481 	 */
2482 	phys_blkno = ocfs2_clusters_to_blocks(osb->sb, phys);
2483 	ret = ocfs2_dx_dir_format_cluster(osb, handle, dir, dx_leaves,
2484 					  num_dx_leaves, phys_blkno);
2485 	if (ret) {
2486 		mlog_errno(ret);
2487 		goto out;
2488 	}
2489 
2490 	*ret_phys_blkno = phys_blkno;
2491 out:
2492 	return ret;
2493 }
2494 
2495 static int ocfs2_dx_dir_new_cluster(struct inode *dir,
2496 				    struct ocfs2_extent_tree *et,
2497 				    u32 cpos, handle_t *handle,
2498 				    struct ocfs2_alloc_context *data_ac,
2499 				    struct ocfs2_alloc_context *meta_ac,
2500 				    struct buffer_head **dx_leaves,
2501 				    int num_dx_leaves)
2502 {
2503 	int ret;
2504 	u64 phys_blkno;
2505 
2506 	ret = __ocfs2_dx_dir_new_cluster(dir, cpos, handle, data_ac, dx_leaves,
2507 					 num_dx_leaves, &phys_blkno);
2508 	if (ret) {
2509 		mlog_errno(ret);
2510 		goto out;
2511 	}
2512 
2513 	ret = ocfs2_insert_extent(handle, et, cpos, phys_blkno, 1, 0,
2514 				  meta_ac);
2515 	if (ret)
2516 		mlog_errno(ret);
2517 out:
2518 	return ret;
2519 }
2520 
2521 static struct buffer_head **ocfs2_dx_dir_kmalloc_leaves(struct super_block *sb,
2522 							int *ret_num_leaves)
2523 {
2524 	int num_dx_leaves = ocfs2_clusters_to_blocks(sb, 1);
2525 	struct buffer_head **dx_leaves;
2526 
2527 	dx_leaves = kcalloc(num_dx_leaves, sizeof(struct buffer_head *),
2528 			    GFP_NOFS);
2529 	if (dx_leaves && ret_num_leaves)
2530 		*ret_num_leaves = num_dx_leaves;
2531 
2532 	return dx_leaves;
2533 }
2534 
2535 static int ocfs2_fill_new_dir_dx(struct ocfs2_super *osb,
2536 				 handle_t *handle,
2537 				 struct inode *parent,
2538 				 struct inode *inode,
2539 				 struct buffer_head *di_bh,
2540 				 struct ocfs2_alloc_context *data_ac,
2541 				 struct ocfs2_alloc_context *meta_ac)
2542 {
2543 	int ret;
2544 	struct buffer_head *leaf_bh = NULL;
2545 	struct buffer_head *dx_root_bh = NULL;
2546 	struct ocfs2_dx_hinfo hinfo;
2547 	struct ocfs2_dx_root_block *dx_root;
2548 	struct ocfs2_dx_entry_list *entry_list;
2549 
2550 	/*
2551 	 * Our strategy is to create the directory as though it were
2552 	 * unindexed, then add the index block. This works with very
2553 	 * little complication since the state of a new directory is a
2554 	 * very well known quantity.
2555 	 *
2556 	 * Essentially, we have two dirents ("." and ".."), in the 1st
2557 	 * block which need indexing. These are easily inserted into
2558 	 * the index block.
2559 	 */
2560 
2561 	ret = ocfs2_fill_new_dir_el(osb, handle, parent, inode, di_bh,
2562 				    data_ac, &leaf_bh);
2563 	if (ret) {
2564 		mlog_errno(ret);
2565 		goto out;
2566 	}
2567 
2568 	ret = ocfs2_dx_dir_attach_index(osb, handle, inode, di_bh, leaf_bh,
2569 					meta_ac, 1, 2, &dx_root_bh);
2570 	if (ret) {
2571 		mlog_errno(ret);
2572 		goto out;
2573 	}
2574 	dx_root = (struct ocfs2_dx_root_block *)dx_root_bh->b_data;
2575 	entry_list = &dx_root->dr_entries;
2576 
2577 	/* Buffer has been journaled for us by ocfs2_dx_dir_attach_index */
2578 	ocfs2_dx_dir_name_hash(inode, ".", 1, &hinfo);
2579 	ocfs2_dx_entry_list_insert(entry_list, &hinfo, leaf_bh->b_blocknr);
2580 
2581 	ocfs2_dx_dir_name_hash(inode, "..", 2, &hinfo);
2582 	ocfs2_dx_entry_list_insert(entry_list, &hinfo, leaf_bh->b_blocknr);
2583 
2584 out:
2585 	brelse(dx_root_bh);
2586 	brelse(leaf_bh);
2587 	return ret;
2588 }
2589 
2590 int ocfs2_fill_new_dir(struct ocfs2_super *osb,
2591 		       handle_t *handle,
2592 		       struct inode *parent,
2593 		       struct inode *inode,
2594 		       struct buffer_head *fe_bh,
2595 		       struct ocfs2_alloc_context *data_ac,
2596 		       struct ocfs2_alloc_context *meta_ac)
2597 
2598 {
2599 	BUG_ON(!ocfs2_supports_inline_data(osb) && data_ac == NULL);
2600 
2601 	if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
2602 		return ocfs2_fill_new_dir_id(osb, handle, parent, inode, fe_bh);
2603 
2604 	if (ocfs2_supports_indexed_dirs(osb))
2605 		return ocfs2_fill_new_dir_dx(osb, handle, parent, inode, fe_bh,
2606 					     data_ac, meta_ac);
2607 
2608 	return ocfs2_fill_new_dir_el(osb, handle, parent, inode, fe_bh,
2609 				     data_ac, NULL);
2610 }
2611 
2612 static int ocfs2_dx_dir_index_block(struct inode *dir,
2613 				    handle_t *handle,
2614 				    struct buffer_head **dx_leaves,
2615 				    int num_dx_leaves,
2616 				    u32 *num_dx_entries,
2617 				    struct buffer_head *dirent_bh)
2618 {
2619 	int ret = 0, namelen, i;
2620 	char *de_buf, *limit;
2621 	struct ocfs2_dir_entry *de;
2622 	struct buffer_head *dx_leaf_bh;
2623 	struct ocfs2_dx_hinfo hinfo;
2624 	u64 dirent_blk = dirent_bh->b_blocknr;
2625 
2626 	de_buf = dirent_bh->b_data;
2627 	limit = de_buf + dir->i_sb->s_blocksize;
2628 
2629 	while (de_buf < limit) {
2630 		de = (struct ocfs2_dir_entry *)de_buf;
2631 
2632 		namelen = de->name_len;
2633 		if (!namelen || !de->inode)
2634 			goto inc;
2635 
2636 		ocfs2_dx_dir_name_hash(dir, de->name, namelen, &hinfo);
2637 
2638 		i = ocfs2_dx_dir_hash_idx(OCFS2_SB(dir->i_sb), &hinfo);
2639 		dx_leaf_bh = dx_leaves[i];
2640 
2641 		ret = __ocfs2_dx_dir_leaf_insert(dir, handle, &hinfo,
2642 						 dirent_blk, dx_leaf_bh);
2643 		if (ret) {
2644 			mlog_errno(ret);
2645 			goto out;
2646 		}
2647 
2648 		*num_dx_entries = *num_dx_entries + 1;
2649 
2650 inc:
2651 		de_buf += le16_to_cpu(de->rec_len);
2652 	}
2653 
2654 out:
2655 	return ret;
2656 }
2657 
2658 /*
2659  * XXX: This expects dx_root_bh to already be part of the transaction.
2660  */
2661 static void ocfs2_dx_dir_index_root_block(struct inode *dir,
2662 					 struct buffer_head *dx_root_bh,
2663 					 struct buffer_head *dirent_bh)
2664 {
2665 	char *de_buf, *limit;
2666 	struct ocfs2_dx_root_block *dx_root;
2667 	struct ocfs2_dir_entry *de;
2668 	struct ocfs2_dx_hinfo hinfo;
2669 	u64 dirent_blk = dirent_bh->b_blocknr;
2670 
2671 	dx_root = (struct ocfs2_dx_root_block *)dx_root_bh->b_data;
2672 
2673 	de_buf = dirent_bh->b_data;
2674 	limit = de_buf + dir->i_sb->s_blocksize;
2675 
2676 	while (de_buf < limit) {
2677 		de = (struct ocfs2_dir_entry *)de_buf;
2678 
2679 		if (!de->name_len || !de->inode)
2680 			goto inc;
2681 
2682 		ocfs2_dx_dir_name_hash(dir, de->name, de->name_len, &hinfo);
2683 
2684 		trace_ocfs2_dx_dir_index_root_block(
2685 				(unsigned long long)dir->i_ino,
2686 				hinfo.major_hash, hinfo.minor_hash,
2687 				de->name_len, de->name,
2688 				le16_to_cpu(dx_root->dr_entries.de_num_used));
2689 
2690 		ocfs2_dx_entry_list_insert(&dx_root->dr_entries, &hinfo,
2691 					   dirent_blk);
2692 
2693 		le32_add_cpu(&dx_root->dr_num_entries, 1);
2694 inc:
2695 		de_buf += le16_to_cpu(de->rec_len);
2696 	}
2697 }
2698 
2699 /*
2700  * Count the number of inline directory entries in di_bh and compare
2701  * them against the number of entries we can hold in an inline dx root
2702  * block.
2703  */
2704 static int ocfs2_new_dx_should_be_inline(struct inode *dir,
2705 					 struct buffer_head *di_bh)
2706 {
2707 	int dirent_count = 0;
2708 	char *de_buf, *limit;
2709 	struct ocfs2_dir_entry *de;
2710 	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
2711 
2712 	de_buf = di->id2.i_data.id_data;
2713 	limit = de_buf + i_size_read(dir);
2714 
2715 	while (de_buf < limit) {
2716 		de = (struct ocfs2_dir_entry *)de_buf;
2717 
2718 		if (de->name_len && de->inode)
2719 			dirent_count++;
2720 
2721 		de_buf += le16_to_cpu(de->rec_len);
2722 	}
2723 
2724 	/* We are careful to leave room for one extra record. */
2725 	return dirent_count < ocfs2_dx_entries_per_root(dir->i_sb);
2726 }
2727 
2728 /*
2729  * Expand rec_len of the rightmost dirent in a directory block so that it
2730  * contains the end of our valid space for dirents. We do this during
2731  * expansion from an inline directory to one with extents. The first dir block
2732  * in that case is taken from the inline data portion of the inode block.
2733  *
2734  * This will also return the largest amount of contiguous space for a dirent
2735  * in the block. That value is *not* necessarily the last dirent, even after
2736  * expansion. The directory indexing code wants this value for free space
2737  * accounting. We do this here since we're already walking the entire dir
2738  * block.
2739  *
2740  * We add the dir trailer if this filesystem wants it.
2741  */
2742 static unsigned int ocfs2_expand_last_dirent(char *start, unsigned int old_size,
2743 					     struct inode *dir)
2744 {
2745 	struct super_block *sb = dir->i_sb;
2746 	struct ocfs2_dir_entry *de;
2747 	struct ocfs2_dir_entry *prev_de;
2748 	char *de_buf, *limit;
2749 	unsigned int new_size = sb->s_blocksize;
2750 	unsigned int bytes, this_hole;
2751 	unsigned int largest_hole = 0;
2752 
2753 	if (ocfs2_new_dir_wants_trailer(dir))
2754 		new_size = ocfs2_dir_trailer_blk_off(sb);
2755 
2756 	bytes = new_size - old_size;
2757 
2758 	limit = start + old_size;
2759 	de_buf = start;
2760 	de = (struct ocfs2_dir_entry *)de_buf;
2761 	do {
2762 		this_hole = ocfs2_figure_dirent_hole(de);
2763 		if (this_hole > largest_hole)
2764 			largest_hole = this_hole;
2765 
2766 		prev_de = de;
2767 		de_buf += le16_to_cpu(de->rec_len);
2768 		de = (struct ocfs2_dir_entry *)de_buf;
2769 	} while (de_buf < limit);
2770 
2771 	le16_add_cpu(&prev_de->rec_len, bytes);
2772 
2773 	/* We need to double check this after modification of the final
2774 	 * dirent. */
2775 	this_hole = ocfs2_figure_dirent_hole(prev_de);
2776 	if (this_hole > largest_hole)
2777 		largest_hole = this_hole;
2778 
2779 	if (largest_hole >= OCFS2_DIR_MIN_REC_LEN)
2780 		return largest_hole;
2781 	return 0;
2782 }
2783 
2784 /*
2785  * We allocate enough clusters to fulfill "blocks_wanted", but set
2786  * i_size to exactly one block. Ocfs2_extend_dir() will handle the
2787  * rest automatically for us.
2788  *
2789  * *first_block_bh is a pointer to the 1st data block allocated to the
2790  *  directory.
2791  */
2792 static int ocfs2_expand_inline_dir(struct inode *dir, struct buffer_head *di_bh,
2793 				   unsigned int blocks_wanted,
2794 				   struct ocfs2_dir_lookup_result *lookup,
2795 				   struct buffer_head **first_block_bh)
2796 {
2797 	u32 alloc, dx_alloc, bit_off, len, num_dx_entries = 0;
2798 	struct super_block *sb = dir->i_sb;
2799 	int ret, i, num_dx_leaves = 0, dx_inline = 0,
2800 		credits = ocfs2_inline_to_extents_credits(sb);
2801 	u64 dx_insert_blkno, blkno,
2802 		bytes = blocks_wanted << sb->s_blocksize_bits;
2803 	struct ocfs2_super *osb = OCFS2_SB(dir->i_sb);
2804 	struct ocfs2_inode_info *oi = OCFS2_I(dir);
2805 	struct ocfs2_alloc_context *data_ac = NULL;
2806 	struct ocfs2_alloc_context *meta_ac = NULL;
2807 	struct buffer_head *dirdata_bh = NULL;
2808 	struct buffer_head *dx_root_bh = NULL;
2809 	struct buffer_head **dx_leaves = NULL;
2810 	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
2811 	handle_t *handle;
2812 	struct ocfs2_extent_tree et;
2813 	struct ocfs2_extent_tree dx_et;
2814 	int did_quota = 0, bytes_allocated = 0;
2815 
2816 	ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(dir), di_bh);
2817 
2818 	alloc = ocfs2_clusters_for_bytes(sb, bytes);
2819 	dx_alloc = 0;
2820 
2821 	down_write(&oi->ip_alloc_sem);
2822 
2823 	if (ocfs2_supports_indexed_dirs(osb)) {
2824 		credits += ocfs2_add_dir_index_credits(sb);
2825 
2826 		dx_inline = ocfs2_new_dx_should_be_inline(dir, di_bh);
2827 		if (!dx_inline) {
2828 			/* Add one more cluster for an index leaf */
2829 			dx_alloc++;
2830 			dx_leaves = ocfs2_dx_dir_kmalloc_leaves(sb,
2831 								&num_dx_leaves);
2832 			if (!dx_leaves) {
2833 				ret = -ENOMEM;
2834 				mlog_errno(ret);
2835 				goto out;
2836 			}
2837 		}
2838 
2839 		/* This gets us the dx_root */
2840 		ret = ocfs2_reserve_new_metadata_blocks(osb, 1, &meta_ac);
2841 		if (ret) {
2842 			mlog_errno(ret);
2843 			goto out;
2844 		}
2845 	}
2846 
2847 	/*
2848 	 * We should never need more than 2 clusters for the unindexed
2849 	 * tree - maximum dirent size is far less than one block. In
2850 	 * fact, the only time we'd need more than one cluster is if
2851 	 * blocksize == clustersize and the dirent won't fit in the
2852 	 * extra space that the expansion to a single block gives. As
2853 	 * of today, that only happens on 4k/4k file systems.
2854 	 */
2855 	BUG_ON(alloc > 2);
2856 
2857 	ret = ocfs2_reserve_clusters(osb, alloc + dx_alloc, &data_ac);
2858 	if (ret) {
2859 		mlog_errno(ret);
2860 		goto out;
2861 	}
2862 
2863 	/*
2864 	 * Prepare for worst case allocation scenario of two separate
2865 	 * extents in the unindexed tree.
2866 	 */
2867 	if (alloc == 2)
2868 		credits += OCFS2_SUBALLOC_ALLOC;
2869 
2870 	handle = ocfs2_start_trans(osb, credits);
2871 	if (IS_ERR(handle)) {
2872 		ret = PTR_ERR(handle);
2873 		mlog_errno(ret);
2874 		goto out;
2875 	}
2876 
2877 	ret = dquot_alloc_space_nodirty(dir,
2878 		ocfs2_clusters_to_bytes(osb->sb, alloc + dx_alloc));
2879 	if (ret)
2880 		goto out_commit;
2881 	did_quota = 1;
2882 
2883 	if (ocfs2_supports_indexed_dirs(osb) && !dx_inline) {
2884 		/*
2885 		 * Allocate our index cluster first, to maximize the
2886 		 * possibility that unindexed leaves grow
2887 		 * contiguously.
2888 		 */
2889 		ret = __ocfs2_dx_dir_new_cluster(dir, 0, handle, data_ac,
2890 						 dx_leaves, num_dx_leaves,
2891 						 &dx_insert_blkno);
2892 		if (ret) {
2893 			mlog_errno(ret);
2894 			goto out_commit;
2895 		}
2896 		bytes_allocated += ocfs2_clusters_to_bytes(dir->i_sb, 1);
2897 	}
2898 
2899 	/*
2900 	 * Try to claim as many clusters as the bitmap can give though
2901 	 * if we only get one now, that's enough to continue. The rest
2902 	 * will be claimed after the conversion to extents.
2903 	 */
2904 	if (ocfs2_dir_resv_allowed(osb))
2905 		data_ac->ac_resv = &oi->ip_la_data_resv;
2906 	ret = ocfs2_claim_clusters(handle, data_ac, 1, &bit_off, &len);
2907 	if (ret) {
2908 		mlog_errno(ret);
2909 		goto out_commit;
2910 	}
2911 	bytes_allocated += ocfs2_clusters_to_bytes(dir->i_sb, 1);
2912 
2913 	/*
2914 	 * Operations are carefully ordered so that we set up the new
2915 	 * data block first. The conversion from inline data to
2916 	 * extents follows.
2917 	 */
2918 	blkno = ocfs2_clusters_to_blocks(dir->i_sb, bit_off);
2919 	dirdata_bh = sb_getblk(sb, blkno);
2920 	if (!dirdata_bh) {
2921 		ret = -ENOMEM;
2922 		mlog_errno(ret);
2923 		goto out_commit;
2924 	}
2925 
2926 	ocfs2_set_new_buffer_uptodate(INODE_CACHE(dir), dirdata_bh);
2927 
2928 	ret = ocfs2_journal_access_db(handle, INODE_CACHE(dir), dirdata_bh,
2929 				      OCFS2_JOURNAL_ACCESS_CREATE);
2930 	if (ret) {
2931 		mlog_errno(ret);
2932 		goto out_commit;
2933 	}
2934 
2935 	memcpy(dirdata_bh->b_data, di->id2.i_data.id_data, i_size_read(dir));
2936 	memset(dirdata_bh->b_data + i_size_read(dir), 0,
2937 	       sb->s_blocksize - i_size_read(dir));
2938 	i = ocfs2_expand_last_dirent(dirdata_bh->b_data, i_size_read(dir), dir);
2939 	if (ocfs2_new_dir_wants_trailer(dir)) {
2940 		/*
2941 		 * Prepare the dir trailer up front. It will otherwise look
2942 		 * like a valid dirent. Even if inserting the index fails
2943 		 * (unlikely), then all we'll have done is given first dir
2944 		 * block a small amount of fragmentation.
2945 		 */
2946 		ocfs2_init_dir_trailer(dir, dirdata_bh, i);
2947 	}
2948 
2949 	ocfs2_update_inode_fsync_trans(handle, dir, 1);
2950 	ocfs2_journal_dirty(handle, dirdata_bh);
2951 
2952 	if (ocfs2_supports_indexed_dirs(osb) && !dx_inline) {
2953 		/*
2954 		 * Dx dirs with an external cluster need to do this up
2955 		 * front. Inline dx root's get handled later, after
2956 		 * we've allocated our root block. We get passed back
2957 		 * a total number of items so that dr_num_entries can
2958 		 * be correctly set once the dx_root has been
2959 		 * allocated.
2960 		 */
2961 		ret = ocfs2_dx_dir_index_block(dir, handle, dx_leaves,
2962 					       num_dx_leaves, &num_dx_entries,
2963 					       dirdata_bh);
2964 		if (ret) {
2965 			mlog_errno(ret);
2966 			goto out_commit;
2967 		}
2968 	}
2969 
2970 	/*
2971 	 * Set extent, i_size, etc on the directory. After this, the
2972 	 * inode should contain the same exact dirents as before and
2973 	 * be fully accessible from system calls.
2974 	 *
2975 	 * We let the later dirent insert modify c/mtime - to the user
2976 	 * the data hasn't changed.
2977 	 */
2978 	ret = ocfs2_journal_access_di(handle, INODE_CACHE(dir), di_bh,
2979 				      OCFS2_JOURNAL_ACCESS_CREATE);
2980 	if (ret) {
2981 		mlog_errno(ret);
2982 		goto out_commit;
2983 	}
2984 
2985 	spin_lock(&oi->ip_lock);
2986 	oi->ip_dyn_features &= ~OCFS2_INLINE_DATA_FL;
2987 	di->i_dyn_features = cpu_to_le16(oi->ip_dyn_features);
2988 	spin_unlock(&oi->ip_lock);
2989 
2990 	ocfs2_dinode_new_extent_list(dir, di);
2991 
2992 	i_size_write(dir, sb->s_blocksize);
2993 	dir->i_mtime = dir->i_ctime = current_time(dir);
2994 
2995 	di->i_size = cpu_to_le64(sb->s_blocksize);
2996 	di->i_ctime = di->i_mtime = cpu_to_le64(dir->i_ctime.tv_sec);
2997 	di->i_ctime_nsec = di->i_mtime_nsec = cpu_to_le32(dir->i_ctime.tv_nsec);
2998 	ocfs2_update_inode_fsync_trans(handle, dir, 1);
2999 
3000 	/*
3001 	 * This should never fail as our extent list is empty and all
3002 	 * related blocks have been journaled already.
3003 	 */
3004 	ret = ocfs2_insert_extent(handle, &et, 0, blkno, len,
3005 				  0, NULL);
3006 	if (ret) {
3007 		mlog_errno(ret);
3008 		goto out_commit;
3009 	}
3010 
3011 	/*
3012 	 * Set i_blocks after the extent insert for the most up to
3013 	 * date ip_clusters value.
3014 	 */
3015 	dir->i_blocks = ocfs2_inode_sector_count(dir);
3016 
3017 	ocfs2_journal_dirty(handle, di_bh);
3018 
3019 	if (ocfs2_supports_indexed_dirs(osb)) {
3020 		ret = ocfs2_dx_dir_attach_index(osb, handle, dir, di_bh,
3021 						dirdata_bh, meta_ac, dx_inline,
3022 						num_dx_entries, &dx_root_bh);
3023 		if (ret) {
3024 			mlog_errno(ret);
3025 			goto out_commit;
3026 		}
3027 
3028 		if (dx_inline) {
3029 			ocfs2_dx_dir_index_root_block(dir, dx_root_bh,
3030 						      dirdata_bh);
3031 		} else {
3032 			ocfs2_init_dx_root_extent_tree(&dx_et,
3033 						       INODE_CACHE(dir),
3034 						       dx_root_bh);
3035 			ret = ocfs2_insert_extent(handle, &dx_et, 0,
3036 						  dx_insert_blkno, 1, 0, NULL);
3037 			if (ret)
3038 				mlog_errno(ret);
3039 		}
3040 	}
3041 
3042 	/*
3043 	 * We asked for two clusters, but only got one in the 1st
3044 	 * pass. Claim the 2nd cluster as a separate extent.
3045 	 */
3046 	if (alloc > len) {
3047 		ret = ocfs2_claim_clusters(handle, data_ac, 1, &bit_off,
3048 					   &len);
3049 		if (ret) {
3050 			mlog_errno(ret);
3051 			goto out_commit;
3052 		}
3053 		blkno = ocfs2_clusters_to_blocks(dir->i_sb, bit_off);
3054 
3055 		ret = ocfs2_insert_extent(handle, &et, 1,
3056 					  blkno, len, 0, NULL);
3057 		if (ret) {
3058 			mlog_errno(ret);
3059 			goto out_commit;
3060 		}
3061 		bytes_allocated += ocfs2_clusters_to_bytes(dir->i_sb, 1);
3062 	}
3063 
3064 	*first_block_bh = dirdata_bh;
3065 	dirdata_bh = NULL;
3066 	if (ocfs2_supports_indexed_dirs(osb)) {
3067 		unsigned int off;
3068 
3069 		if (!dx_inline) {
3070 			/*
3071 			 * We need to return the correct block within the
3072 			 * cluster which should hold our entry.
3073 			 */
3074 			off = ocfs2_dx_dir_hash_idx(OCFS2_SB(dir->i_sb),
3075 						    &lookup->dl_hinfo);
3076 			get_bh(dx_leaves[off]);
3077 			lookup->dl_dx_leaf_bh = dx_leaves[off];
3078 		}
3079 		lookup->dl_dx_root_bh = dx_root_bh;
3080 		dx_root_bh = NULL;
3081 	}
3082 
3083 out_commit:
3084 	if (ret < 0 && did_quota)
3085 		dquot_free_space_nodirty(dir, bytes_allocated);
3086 
3087 	ocfs2_commit_trans(osb, handle);
3088 
3089 out:
3090 	up_write(&oi->ip_alloc_sem);
3091 	if (data_ac)
3092 		ocfs2_free_alloc_context(data_ac);
3093 	if (meta_ac)
3094 		ocfs2_free_alloc_context(meta_ac);
3095 
3096 	if (dx_leaves) {
3097 		for (i = 0; i < num_dx_leaves; i++)
3098 			brelse(dx_leaves[i]);
3099 		kfree(dx_leaves);
3100 	}
3101 
3102 	brelse(dirdata_bh);
3103 	brelse(dx_root_bh);
3104 
3105 	return ret;
3106 }
3107 
3108 /* returns a bh of the 1st new block in the allocation. */
3109 static int ocfs2_do_extend_dir(struct super_block *sb,
3110 			       handle_t *handle,
3111 			       struct inode *dir,
3112 			       struct buffer_head *parent_fe_bh,
3113 			       struct ocfs2_alloc_context *data_ac,
3114 			       struct ocfs2_alloc_context *meta_ac,
3115 			       struct buffer_head **new_bh)
3116 {
3117 	int status;
3118 	int extend, did_quota = 0;
3119 	u64 p_blkno, v_blkno;
3120 
3121 	spin_lock(&OCFS2_I(dir)->ip_lock);
3122 	extend = (i_size_read(dir) == ocfs2_clusters_to_bytes(sb, OCFS2_I(dir)->ip_clusters));
3123 	spin_unlock(&OCFS2_I(dir)->ip_lock);
3124 
3125 	if (extend) {
3126 		u32 offset = OCFS2_I(dir)->ip_clusters;
3127 
3128 		status = dquot_alloc_space_nodirty(dir,
3129 					ocfs2_clusters_to_bytes(sb, 1));
3130 		if (status)
3131 			goto bail;
3132 		did_quota = 1;
3133 
3134 		status = ocfs2_add_inode_data(OCFS2_SB(sb), dir, &offset,
3135 					      1, 0, parent_fe_bh, handle,
3136 					      data_ac, meta_ac, NULL);
3137 		BUG_ON(status == -EAGAIN);
3138 		if (status < 0) {
3139 			mlog_errno(status);
3140 			goto bail;
3141 		}
3142 	}
3143 
3144 	v_blkno = ocfs2_blocks_for_bytes(sb, i_size_read(dir));
3145 	status = ocfs2_extent_map_get_blocks(dir, v_blkno, &p_blkno, NULL, NULL);
3146 	if (status < 0) {
3147 		mlog_errno(status);
3148 		goto bail;
3149 	}
3150 
3151 	*new_bh = sb_getblk(sb, p_blkno);
3152 	if (!*new_bh) {
3153 		status = -ENOMEM;
3154 		mlog_errno(status);
3155 		goto bail;
3156 	}
3157 	status = 0;
3158 bail:
3159 	if (did_quota && status < 0)
3160 		dquot_free_space_nodirty(dir, ocfs2_clusters_to_bytes(sb, 1));
3161 	return status;
3162 }
3163 
3164 /*
3165  * Assumes you already have a cluster lock on the directory.
3166  *
3167  * 'blocks_wanted' is only used if we have an inline directory which
3168  * is to be turned into an extent based one. The size of the dirent to
3169  * insert might be larger than the space gained by growing to just one
3170  * block, so we may have to grow the inode by two blocks in that case.
3171  *
3172  * If the directory is already indexed, dx_root_bh must be provided.
3173  */
3174 static int ocfs2_extend_dir(struct ocfs2_super *osb,
3175 			    struct inode *dir,
3176 			    struct buffer_head *parent_fe_bh,
3177 			    unsigned int blocks_wanted,
3178 			    struct ocfs2_dir_lookup_result *lookup,
3179 			    struct buffer_head **new_de_bh)
3180 {
3181 	int status = 0;
3182 	int credits, num_free_extents, drop_alloc_sem = 0;
3183 	loff_t dir_i_size;
3184 	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) parent_fe_bh->b_data;
3185 	struct ocfs2_extent_list *el = &fe->id2.i_list;
3186 	struct ocfs2_alloc_context *data_ac = NULL;
3187 	struct ocfs2_alloc_context *meta_ac = NULL;
3188 	handle_t *handle = NULL;
3189 	struct buffer_head *new_bh = NULL;
3190 	struct ocfs2_dir_entry * de;
3191 	struct super_block *sb = osb->sb;
3192 	struct ocfs2_extent_tree et;
3193 	struct buffer_head *dx_root_bh = lookup->dl_dx_root_bh;
3194 
3195 	if (OCFS2_I(dir)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
3196 		/*
3197 		 * This would be a code error as an inline directory should
3198 		 * never have an index root.
3199 		 */
3200 		BUG_ON(dx_root_bh);
3201 
3202 		status = ocfs2_expand_inline_dir(dir, parent_fe_bh,
3203 						 blocks_wanted, lookup,
3204 						 &new_bh);
3205 		if (status) {
3206 			mlog_errno(status);
3207 			goto bail;
3208 		}
3209 
3210 		/* Expansion from inline to an indexed directory will
3211 		 * have given us this. */
3212 		dx_root_bh = lookup->dl_dx_root_bh;
3213 
3214 		if (blocks_wanted == 1) {
3215 			/*
3216 			 * If the new dirent will fit inside the space
3217 			 * created by pushing out to one block, then
3218 			 * we can complete the operation
3219 			 * here. Otherwise we have to expand i_size
3220 			 * and format the 2nd block below.
3221 			 */
3222 			BUG_ON(new_bh == NULL);
3223 			goto bail_bh;
3224 		}
3225 
3226 		/*
3227 		 * Get rid of 'new_bh' - we want to format the 2nd
3228 		 * data block and return that instead.
3229 		 */
3230 		brelse(new_bh);
3231 		new_bh = NULL;
3232 
3233 		down_write(&OCFS2_I(dir)->ip_alloc_sem);
3234 		drop_alloc_sem = 1;
3235 		dir_i_size = i_size_read(dir);
3236 		credits = OCFS2_SIMPLE_DIR_EXTEND_CREDITS;
3237 		goto do_extend;
3238 	}
3239 
3240 	down_write(&OCFS2_I(dir)->ip_alloc_sem);
3241 	drop_alloc_sem = 1;
3242 	dir_i_size = i_size_read(dir);
3243 	trace_ocfs2_extend_dir((unsigned long long)OCFS2_I(dir)->ip_blkno,
3244 			       dir_i_size);
3245 
3246 	/* dir->i_size is always block aligned. */
3247 	spin_lock(&OCFS2_I(dir)->ip_lock);
3248 	if (dir_i_size == ocfs2_clusters_to_bytes(sb, OCFS2_I(dir)->ip_clusters)) {
3249 		spin_unlock(&OCFS2_I(dir)->ip_lock);
3250 		ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(dir),
3251 					      parent_fe_bh);
3252 		num_free_extents = ocfs2_num_free_extents(osb, &et);
3253 		if (num_free_extents < 0) {
3254 			status = num_free_extents;
3255 			mlog_errno(status);
3256 			goto bail;
3257 		}
3258 
3259 		if (!num_free_extents) {
3260 			status = ocfs2_reserve_new_metadata(osb, el, &meta_ac);
3261 			if (status < 0) {
3262 				if (status != -ENOSPC)
3263 					mlog_errno(status);
3264 				goto bail;
3265 			}
3266 		}
3267 
3268 		status = ocfs2_reserve_clusters(osb, 1, &data_ac);
3269 		if (status < 0) {
3270 			if (status != -ENOSPC)
3271 				mlog_errno(status);
3272 			goto bail;
3273 		}
3274 
3275 		if (ocfs2_dir_resv_allowed(osb))
3276 			data_ac->ac_resv = &OCFS2_I(dir)->ip_la_data_resv;
3277 
3278 		credits = ocfs2_calc_extend_credits(sb, el);
3279 	} else {
3280 		spin_unlock(&OCFS2_I(dir)->ip_lock);
3281 		credits = OCFS2_SIMPLE_DIR_EXTEND_CREDITS;
3282 	}
3283 
3284 do_extend:
3285 	if (ocfs2_dir_indexed(dir))
3286 		credits++; /* For attaching the new dirent block to the
3287 			    * dx_root */
3288 
3289 	handle = ocfs2_start_trans(osb, credits);
3290 	if (IS_ERR(handle)) {
3291 		status = PTR_ERR(handle);
3292 		handle = NULL;
3293 		mlog_errno(status);
3294 		goto bail;
3295 	}
3296 
3297 	status = ocfs2_do_extend_dir(osb->sb, handle, dir, parent_fe_bh,
3298 				     data_ac, meta_ac, &new_bh);
3299 	if (status < 0) {
3300 		mlog_errno(status);
3301 		goto bail;
3302 	}
3303 
3304 	ocfs2_set_new_buffer_uptodate(INODE_CACHE(dir), new_bh);
3305 
3306 	status = ocfs2_journal_access_db(handle, INODE_CACHE(dir), new_bh,
3307 					 OCFS2_JOURNAL_ACCESS_CREATE);
3308 	if (status < 0) {
3309 		mlog_errno(status);
3310 		goto bail;
3311 	}
3312 	memset(new_bh->b_data, 0, sb->s_blocksize);
3313 
3314 	de = (struct ocfs2_dir_entry *) new_bh->b_data;
3315 	de->inode = 0;
3316 	if (ocfs2_supports_dir_trailer(dir)) {
3317 		de->rec_len = cpu_to_le16(ocfs2_dir_trailer_blk_off(sb));
3318 
3319 		ocfs2_init_dir_trailer(dir, new_bh, le16_to_cpu(de->rec_len));
3320 
3321 		if (ocfs2_dir_indexed(dir)) {
3322 			status = ocfs2_dx_dir_link_trailer(dir, handle,
3323 							   dx_root_bh, new_bh);
3324 			if (status) {
3325 				mlog_errno(status);
3326 				goto bail;
3327 			}
3328 		}
3329 	} else {
3330 		de->rec_len = cpu_to_le16(sb->s_blocksize);
3331 	}
3332 	ocfs2_update_inode_fsync_trans(handle, dir, 1);
3333 	ocfs2_journal_dirty(handle, new_bh);
3334 
3335 	dir_i_size += dir->i_sb->s_blocksize;
3336 	i_size_write(dir, dir_i_size);
3337 	dir->i_blocks = ocfs2_inode_sector_count(dir);
3338 	status = ocfs2_mark_inode_dirty(handle, dir, parent_fe_bh);
3339 	if (status < 0) {
3340 		mlog_errno(status);
3341 		goto bail;
3342 	}
3343 
3344 bail_bh:
3345 	*new_de_bh = new_bh;
3346 	get_bh(*new_de_bh);
3347 bail:
3348 	if (handle)
3349 		ocfs2_commit_trans(osb, handle);
3350 	if (drop_alloc_sem)
3351 		up_write(&OCFS2_I(dir)->ip_alloc_sem);
3352 
3353 	if (data_ac)
3354 		ocfs2_free_alloc_context(data_ac);
3355 	if (meta_ac)
3356 		ocfs2_free_alloc_context(meta_ac);
3357 
3358 	brelse(new_bh);
3359 
3360 	return status;
3361 }
3362 
3363 static int ocfs2_find_dir_space_id(struct inode *dir, struct buffer_head *di_bh,
3364 				   const char *name, int namelen,
3365 				   struct buffer_head **ret_de_bh,
3366 				   unsigned int *blocks_wanted)
3367 {
3368 	int ret;
3369 	struct super_block *sb = dir->i_sb;
3370 	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
3371 	struct ocfs2_dir_entry *de, *last_de = NULL;
3372 	char *de_buf, *limit;
3373 	unsigned long offset = 0;
3374 	unsigned int rec_len, new_rec_len, free_space = dir->i_sb->s_blocksize;
3375 
3376 	/*
3377 	 * This calculates how many free bytes we'd have in block zero, should
3378 	 * this function force expansion to an extent tree.
3379 	 */
3380 	if (ocfs2_new_dir_wants_trailer(dir))
3381 		free_space = ocfs2_dir_trailer_blk_off(sb) - i_size_read(dir);
3382 	else
3383 		free_space = dir->i_sb->s_blocksize - i_size_read(dir);
3384 
3385 	de_buf = di->id2.i_data.id_data;
3386 	limit = de_buf + i_size_read(dir);
3387 	rec_len = OCFS2_DIR_REC_LEN(namelen);
3388 
3389 	while (de_buf < limit) {
3390 		de = (struct ocfs2_dir_entry *)de_buf;
3391 
3392 		if (!ocfs2_check_dir_entry(dir, de, di_bh, offset)) {
3393 			ret = -ENOENT;
3394 			goto out;
3395 		}
3396 		if (ocfs2_match(namelen, name, de)) {
3397 			ret = -EEXIST;
3398 			goto out;
3399 		}
3400 		/*
3401 		 * No need to check for a trailing dirent record here as
3402 		 * they're not used for inline dirs.
3403 		 */
3404 
3405 		if (ocfs2_dirent_would_fit(de, rec_len)) {
3406 			/* Ok, we found a spot. Return this bh and let
3407 			 * the caller actually fill it in. */
3408 			*ret_de_bh = di_bh;
3409 			get_bh(*ret_de_bh);
3410 			ret = 0;
3411 			goto out;
3412 		}
3413 
3414 		last_de = de;
3415 		de_buf += le16_to_cpu(de->rec_len);
3416 		offset += le16_to_cpu(de->rec_len);
3417 	}
3418 
3419 	/*
3420 	 * We're going to require expansion of the directory - figure
3421 	 * out how many blocks we'll need so that a place for the
3422 	 * dirent can be found.
3423 	 */
3424 	*blocks_wanted = 1;
3425 	new_rec_len = le16_to_cpu(last_de->rec_len) + free_space;
3426 	if (new_rec_len < (rec_len + OCFS2_DIR_REC_LEN(last_de->name_len)))
3427 		*blocks_wanted = 2;
3428 
3429 	ret = -ENOSPC;
3430 out:
3431 	return ret;
3432 }
3433 
3434 static int ocfs2_find_dir_space_el(struct inode *dir, const char *name,
3435 				   int namelen, struct buffer_head **ret_de_bh)
3436 {
3437 	unsigned long offset;
3438 	struct buffer_head *bh = NULL;
3439 	unsigned short rec_len;
3440 	struct ocfs2_dir_entry *de;
3441 	struct super_block *sb = dir->i_sb;
3442 	int status;
3443 	int blocksize = dir->i_sb->s_blocksize;
3444 
3445 	status = ocfs2_read_dir_block(dir, 0, &bh, 0);
3446 	if (status)
3447 		goto bail;
3448 
3449 	rec_len = OCFS2_DIR_REC_LEN(namelen);
3450 	offset = 0;
3451 	de = (struct ocfs2_dir_entry *) bh->b_data;
3452 	while (1) {
3453 		if ((char *)de >= sb->s_blocksize + bh->b_data) {
3454 			brelse(bh);
3455 			bh = NULL;
3456 
3457 			if (i_size_read(dir) <= offset) {
3458 				/*
3459 				 * Caller will have to expand this
3460 				 * directory.
3461 				 */
3462 				status = -ENOSPC;
3463 				goto bail;
3464 			}
3465 			status = ocfs2_read_dir_block(dir,
3466 					     offset >> sb->s_blocksize_bits,
3467 					     &bh, 0);
3468 			if (status)
3469 				goto bail;
3470 
3471 			/* move to next block */
3472 			de = (struct ocfs2_dir_entry *) bh->b_data;
3473 		}
3474 		if (!ocfs2_check_dir_entry(dir, de, bh, offset)) {
3475 			status = -ENOENT;
3476 			goto bail;
3477 		}
3478 		if (ocfs2_match(namelen, name, de)) {
3479 			status = -EEXIST;
3480 			goto bail;
3481 		}
3482 
3483 		if (ocfs2_skip_dir_trailer(dir, de, offset % blocksize,
3484 					   blocksize))
3485 			goto next;
3486 
3487 		if (ocfs2_dirent_would_fit(de, rec_len)) {
3488 			/* Ok, we found a spot. Return this bh and let
3489 			 * the caller actually fill it in. */
3490 			*ret_de_bh = bh;
3491 			get_bh(*ret_de_bh);
3492 			status = 0;
3493 			goto bail;
3494 		}
3495 next:
3496 		offset += le16_to_cpu(de->rec_len);
3497 		de = (struct ocfs2_dir_entry *)((char *) de + le16_to_cpu(de->rec_len));
3498 	}
3499 
3500 bail:
3501 	brelse(bh);
3502 	if (status)
3503 		mlog_errno(status);
3504 
3505 	return status;
3506 }
3507 
3508 static int dx_leaf_sort_cmp(const void *a, const void *b)
3509 {
3510 	const struct ocfs2_dx_entry *entry1 = a;
3511 	const struct ocfs2_dx_entry *entry2 = b;
3512 	u32 major_hash1 = le32_to_cpu(entry1->dx_major_hash);
3513 	u32 major_hash2 = le32_to_cpu(entry2->dx_major_hash);
3514 	u32 minor_hash1 = le32_to_cpu(entry1->dx_minor_hash);
3515 	u32 minor_hash2 = le32_to_cpu(entry2->dx_minor_hash);
3516 
3517 	if (major_hash1 > major_hash2)
3518 		return 1;
3519 	if (major_hash1 < major_hash2)
3520 		return -1;
3521 
3522 	/*
3523 	 * It is not strictly necessary to sort by minor
3524 	 */
3525 	if (minor_hash1 > minor_hash2)
3526 		return 1;
3527 	if (minor_hash1 < minor_hash2)
3528 		return -1;
3529 	return 0;
3530 }
3531 
3532 static void dx_leaf_sort_swap(void *a, void *b, int size)
3533 {
3534 	struct ocfs2_dx_entry *entry1 = a;
3535 	struct ocfs2_dx_entry *entry2 = b;
3536 
3537 	BUG_ON(size != sizeof(*entry1));
3538 
3539 	swap(*entry1, *entry2);
3540 }
3541 
3542 static int ocfs2_dx_leaf_same_major(struct ocfs2_dx_leaf *dx_leaf)
3543 {
3544 	struct ocfs2_dx_entry_list *dl_list = &dx_leaf->dl_list;
3545 	int i, num = le16_to_cpu(dl_list->de_num_used);
3546 
3547 	for (i = 0; i < (num - 1); i++) {
3548 		if (le32_to_cpu(dl_list->de_entries[i].dx_major_hash) !=
3549 		    le32_to_cpu(dl_list->de_entries[i + 1].dx_major_hash))
3550 			return 0;
3551 	}
3552 
3553 	return 1;
3554 }
3555 
3556 /*
3557  * Find the optimal value to split this leaf on. This expects the leaf
3558  * entries to be in sorted order.
3559  *
3560  * leaf_cpos is the cpos of the leaf we're splitting. insert_hash is
3561  * the hash we want to insert.
3562  *
3563  * This function is only concerned with the major hash - that which
3564  * determines which cluster an item belongs to.
3565  */
3566 static int ocfs2_dx_dir_find_leaf_split(struct ocfs2_dx_leaf *dx_leaf,
3567 					u32 leaf_cpos, u32 insert_hash,
3568 					u32 *split_hash)
3569 {
3570 	struct ocfs2_dx_entry_list *dl_list = &dx_leaf->dl_list;
3571 	int i, num_used = le16_to_cpu(dl_list->de_num_used);
3572 	int allsame;
3573 
3574 	/*
3575 	 * There's a couple rare, but nasty corner cases we have to
3576 	 * check for here. All of them involve a leaf where all value
3577 	 * have the same hash, which is what we look for first.
3578 	 *
3579 	 * Most of the time, all of the above is false, and we simply
3580 	 * pick the median value for a split.
3581 	 */
3582 	allsame = ocfs2_dx_leaf_same_major(dx_leaf);
3583 	if (allsame) {
3584 		u32 val = le32_to_cpu(dl_list->de_entries[0].dx_major_hash);
3585 
3586 		if (val == insert_hash) {
3587 			/*
3588 			 * No matter where we would choose to split,
3589 			 * the new entry would want to occupy the same
3590 			 * block as these. Since there's no space left
3591 			 * in their existing block, we know there
3592 			 * won't be space after the split.
3593 			 */
3594 			return -ENOSPC;
3595 		}
3596 
3597 		if (val == leaf_cpos) {
3598 			/*
3599 			 * Because val is the same as leaf_cpos (which
3600 			 * is the smallest value this leaf can have),
3601 			 * yet is not equal to insert_hash, then we
3602 			 * know that insert_hash *must* be larger than
3603 			 * val (and leaf_cpos). At least cpos+1 in value.
3604 			 *
3605 			 * We also know then, that there cannot be an
3606 			 * adjacent extent (otherwise we'd be looking
3607 			 * at it). Choosing this value gives us a
3608 			 * chance to get some contiguousness.
3609 			 */
3610 			*split_hash = leaf_cpos + 1;
3611 			return 0;
3612 		}
3613 
3614 		if (val > insert_hash) {
3615 			/*
3616 			 * val can not be the same as insert hash, and
3617 			 * also must be larger than leaf_cpos. Also,
3618 			 * we know that there can't be a leaf between
3619 			 * cpos and val, otherwise the entries with
3620 			 * hash 'val' would be there.
3621 			 */
3622 			*split_hash = val;
3623 			return 0;
3624 		}
3625 
3626 		*split_hash = insert_hash;
3627 		return 0;
3628 	}
3629 
3630 	/*
3631 	 * Since the records are sorted and the checks above
3632 	 * guaranteed that not all records in this block are the same,
3633 	 * we simple travel forward, from the median, and pick the 1st
3634 	 * record whose value is larger than leaf_cpos.
3635 	 */
3636 	for (i = (num_used / 2); i < num_used; i++)
3637 		if (le32_to_cpu(dl_list->de_entries[i].dx_major_hash) >
3638 		    leaf_cpos)
3639 			break;
3640 
3641 	BUG_ON(i == num_used); /* Should be impossible */
3642 	*split_hash = le32_to_cpu(dl_list->de_entries[i].dx_major_hash);
3643 	return 0;
3644 }
3645 
3646 /*
3647  * Transfer all entries in orig_dx_leaves whose major hash is equal to or
3648  * larger than split_hash into new_dx_leaves. We use a temporary
3649  * buffer (tmp_dx_leaf) to make the changes to the original leaf blocks.
3650  *
3651  * Since the block offset inside a leaf (cluster) is a constant mask
3652  * of minor_hash, we can optimize - an item at block offset X within
3653  * the original cluster, will be at offset X within the new cluster.
3654  */
3655 static void ocfs2_dx_dir_transfer_leaf(struct inode *dir, u32 split_hash,
3656 				       handle_t *handle,
3657 				       struct ocfs2_dx_leaf *tmp_dx_leaf,
3658 				       struct buffer_head **orig_dx_leaves,
3659 				       struct buffer_head **new_dx_leaves,
3660 				       int num_dx_leaves)
3661 {
3662 	int i, j, num_used;
3663 	u32 major_hash;
3664 	struct ocfs2_dx_leaf *orig_dx_leaf, *new_dx_leaf;
3665 	struct ocfs2_dx_entry_list *orig_list, *new_list, *tmp_list;
3666 	struct ocfs2_dx_entry *dx_entry;
3667 
3668 	tmp_list = &tmp_dx_leaf->dl_list;
3669 
3670 	for (i = 0; i < num_dx_leaves; i++) {
3671 		orig_dx_leaf = (struct ocfs2_dx_leaf *) orig_dx_leaves[i]->b_data;
3672 		orig_list = &orig_dx_leaf->dl_list;
3673 		new_dx_leaf = (struct ocfs2_dx_leaf *) new_dx_leaves[i]->b_data;
3674 		new_list = &new_dx_leaf->dl_list;
3675 
3676 		num_used = le16_to_cpu(orig_list->de_num_used);
3677 
3678 		memcpy(tmp_dx_leaf, orig_dx_leaf, dir->i_sb->s_blocksize);
3679 		tmp_list->de_num_used = cpu_to_le16(0);
3680 		memset(&tmp_list->de_entries, 0, sizeof(*dx_entry)*num_used);
3681 
3682 		for (j = 0; j < num_used; j++) {
3683 			dx_entry = &orig_list->de_entries[j];
3684 			major_hash = le32_to_cpu(dx_entry->dx_major_hash);
3685 			if (major_hash >= split_hash)
3686 				ocfs2_dx_dir_leaf_insert_tail(new_dx_leaf,
3687 							      dx_entry);
3688 			else
3689 				ocfs2_dx_dir_leaf_insert_tail(tmp_dx_leaf,
3690 							      dx_entry);
3691 		}
3692 		memcpy(orig_dx_leaf, tmp_dx_leaf, dir->i_sb->s_blocksize);
3693 
3694 		ocfs2_journal_dirty(handle, orig_dx_leaves[i]);
3695 		ocfs2_journal_dirty(handle, new_dx_leaves[i]);
3696 	}
3697 }
3698 
3699 static int ocfs2_dx_dir_rebalance_credits(struct ocfs2_super *osb,
3700 					  struct ocfs2_dx_root_block *dx_root)
3701 {
3702 	int credits = ocfs2_clusters_to_blocks(osb->sb, 3);
3703 
3704 	credits += ocfs2_calc_extend_credits(osb->sb, &dx_root->dr_list);
3705 	credits += ocfs2_quota_trans_credits(osb->sb);
3706 	return credits;
3707 }
3708 
3709 /*
3710  * Find the median value in dx_leaf_bh and allocate a new leaf to move
3711  * half our entries into.
3712  */
3713 static int ocfs2_dx_dir_rebalance(struct ocfs2_super *osb, struct inode *dir,
3714 				  struct buffer_head *dx_root_bh,
3715 				  struct buffer_head *dx_leaf_bh,
3716 				  struct ocfs2_dx_hinfo *hinfo, u32 leaf_cpos,
3717 				  u64 leaf_blkno)
3718 {
3719 	struct ocfs2_dx_leaf *dx_leaf = (struct ocfs2_dx_leaf *)dx_leaf_bh->b_data;
3720 	int credits, ret, i, num_used, did_quota = 0;
3721 	u32 cpos, split_hash, insert_hash = hinfo->major_hash;
3722 	u64 orig_leaves_start;
3723 	int num_dx_leaves;
3724 	struct buffer_head **orig_dx_leaves = NULL;
3725 	struct buffer_head **new_dx_leaves = NULL;
3726 	struct ocfs2_alloc_context *data_ac = NULL, *meta_ac = NULL;
3727 	struct ocfs2_extent_tree et;
3728 	handle_t *handle = NULL;
3729 	struct ocfs2_dx_root_block *dx_root;
3730 	struct ocfs2_dx_leaf *tmp_dx_leaf = NULL;
3731 
3732 	trace_ocfs2_dx_dir_rebalance((unsigned long long)OCFS2_I(dir)->ip_blkno,
3733 				     (unsigned long long)leaf_blkno,
3734 				     insert_hash);
3735 
3736 	ocfs2_init_dx_root_extent_tree(&et, INODE_CACHE(dir), dx_root_bh);
3737 
3738 	dx_root = (struct ocfs2_dx_root_block *)dx_root_bh->b_data;
3739 	/*
3740 	 * XXX: This is a rather large limit. We should use a more
3741 	 * realistic value.
3742 	 */
3743 	if (le32_to_cpu(dx_root->dr_clusters) == UINT_MAX)
3744 		return -ENOSPC;
3745 
3746 	num_used = le16_to_cpu(dx_leaf->dl_list.de_num_used);
3747 	if (num_used < le16_to_cpu(dx_leaf->dl_list.de_count)) {
3748 		mlog(ML_ERROR, "DX Dir: %llu, Asked to rebalance empty leaf: "
3749 		     "%llu, %d\n", (unsigned long long)OCFS2_I(dir)->ip_blkno,
3750 		     (unsigned long long)leaf_blkno, num_used);
3751 		ret = -EIO;
3752 		goto out;
3753 	}
3754 
3755 	orig_dx_leaves = ocfs2_dx_dir_kmalloc_leaves(osb->sb, &num_dx_leaves);
3756 	if (!orig_dx_leaves) {
3757 		ret = -ENOMEM;
3758 		mlog_errno(ret);
3759 		goto out;
3760 	}
3761 
3762 	new_dx_leaves = ocfs2_dx_dir_kmalloc_leaves(osb->sb, NULL);
3763 	if (!new_dx_leaves) {
3764 		ret = -ENOMEM;
3765 		mlog_errno(ret);
3766 		goto out;
3767 	}
3768 
3769 	ret = ocfs2_lock_allocators(dir, &et, 1, 0, &data_ac, &meta_ac);
3770 	if (ret) {
3771 		if (ret != -ENOSPC)
3772 			mlog_errno(ret);
3773 		goto out;
3774 	}
3775 
3776 	credits = ocfs2_dx_dir_rebalance_credits(osb, dx_root);
3777 	handle = ocfs2_start_trans(osb, credits);
3778 	if (IS_ERR(handle)) {
3779 		ret = PTR_ERR(handle);
3780 		handle = NULL;
3781 		mlog_errno(ret);
3782 		goto out;
3783 	}
3784 
3785 	ret = dquot_alloc_space_nodirty(dir,
3786 				       ocfs2_clusters_to_bytes(dir->i_sb, 1));
3787 	if (ret)
3788 		goto out_commit;
3789 	did_quota = 1;
3790 
3791 	ret = ocfs2_journal_access_dl(handle, INODE_CACHE(dir), dx_leaf_bh,
3792 				      OCFS2_JOURNAL_ACCESS_WRITE);
3793 	if (ret) {
3794 		mlog_errno(ret);
3795 		goto out_commit;
3796 	}
3797 
3798 	/*
3799 	 * This block is changing anyway, so we can sort it in place.
3800 	 */
3801 	sort(dx_leaf->dl_list.de_entries, num_used,
3802 	     sizeof(struct ocfs2_dx_entry), dx_leaf_sort_cmp,
3803 	     dx_leaf_sort_swap);
3804 
3805 	ocfs2_journal_dirty(handle, dx_leaf_bh);
3806 
3807 	ret = ocfs2_dx_dir_find_leaf_split(dx_leaf, leaf_cpos, insert_hash,
3808 					   &split_hash);
3809 	if (ret) {
3810 		mlog_errno(ret);
3811 		goto  out_commit;
3812 	}
3813 
3814 	trace_ocfs2_dx_dir_rebalance_split(leaf_cpos, split_hash, insert_hash);
3815 
3816 	/*
3817 	 * We have to carefully order operations here. There are items
3818 	 * which want to be in the new cluster before insert, but in
3819 	 * order to put those items in the new cluster, we alter the
3820 	 * old cluster. A failure to insert gets nasty.
3821 	 *
3822 	 * So, start by reserving writes to the old
3823 	 * cluster. ocfs2_dx_dir_new_cluster will reserve writes on
3824 	 * the new cluster for us, before inserting it. The insert
3825 	 * won't happen if there's an error before that. Once the
3826 	 * insert is done then, we can transfer from one leaf into the
3827 	 * other without fear of hitting any error.
3828 	 */
3829 
3830 	/*
3831 	 * The leaf transfer wants some scratch space so that we don't
3832 	 * wind up doing a bunch of expensive memmove().
3833 	 */
3834 	tmp_dx_leaf = kmalloc(osb->sb->s_blocksize, GFP_NOFS);
3835 	if (!tmp_dx_leaf) {
3836 		ret = -ENOMEM;
3837 		mlog_errno(ret);
3838 		goto out_commit;
3839 	}
3840 
3841 	orig_leaves_start = ocfs2_block_to_cluster_start(dir->i_sb, leaf_blkno);
3842 	ret = ocfs2_read_dx_leaves(dir, orig_leaves_start, num_dx_leaves,
3843 				   orig_dx_leaves);
3844 	if (ret) {
3845 		mlog_errno(ret);
3846 		goto out_commit;
3847 	}
3848 
3849 	cpos = split_hash;
3850 	ret = ocfs2_dx_dir_new_cluster(dir, &et, cpos, handle,
3851 				       data_ac, meta_ac, new_dx_leaves,
3852 				       num_dx_leaves);
3853 	if (ret) {
3854 		mlog_errno(ret);
3855 		goto out_commit;
3856 	}
3857 
3858 	for (i = 0; i < num_dx_leaves; i++) {
3859 		ret = ocfs2_journal_access_dl(handle, INODE_CACHE(dir),
3860 					      orig_dx_leaves[i],
3861 					      OCFS2_JOURNAL_ACCESS_WRITE);
3862 		if (ret) {
3863 			mlog_errno(ret);
3864 			goto out_commit;
3865 		}
3866 
3867 		ret = ocfs2_journal_access_dl(handle, INODE_CACHE(dir),
3868 					      new_dx_leaves[i],
3869 					      OCFS2_JOURNAL_ACCESS_WRITE);
3870 		if (ret) {
3871 			mlog_errno(ret);
3872 			goto out_commit;
3873 		}
3874 	}
3875 
3876 	ocfs2_dx_dir_transfer_leaf(dir, split_hash, handle, tmp_dx_leaf,
3877 				   orig_dx_leaves, new_dx_leaves, num_dx_leaves);
3878 
3879 out_commit:
3880 	if (ret < 0 && did_quota)
3881 		dquot_free_space_nodirty(dir,
3882 				ocfs2_clusters_to_bytes(dir->i_sb, 1));
3883 
3884 	ocfs2_update_inode_fsync_trans(handle, dir, 1);
3885 	ocfs2_commit_trans(osb, handle);
3886 
3887 out:
3888 	if (orig_dx_leaves || new_dx_leaves) {
3889 		for (i = 0; i < num_dx_leaves; i++) {
3890 			if (orig_dx_leaves)
3891 				brelse(orig_dx_leaves[i]);
3892 			if (new_dx_leaves)
3893 				brelse(new_dx_leaves[i]);
3894 		}
3895 		kfree(orig_dx_leaves);
3896 		kfree(new_dx_leaves);
3897 	}
3898 
3899 	if (meta_ac)
3900 		ocfs2_free_alloc_context(meta_ac);
3901 	if (data_ac)
3902 		ocfs2_free_alloc_context(data_ac);
3903 
3904 	kfree(tmp_dx_leaf);
3905 	return ret;
3906 }
3907 
3908 static int ocfs2_find_dir_space_dx(struct ocfs2_super *osb, struct inode *dir,
3909 				   struct buffer_head *di_bh,
3910 				   struct buffer_head *dx_root_bh,
3911 				   const char *name, int namelen,
3912 				   struct ocfs2_dir_lookup_result *lookup)
3913 {
3914 	int ret, rebalanced = 0;
3915 	struct ocfs2_dx_root_block *dx_root;
3916 	struct buffer_head *dx_leaf_bh = NULL;
3917 	struct ocfs2_dx_leaf *dx_leaf;
3918 	u64 blkno;
3919 	u32 leaf_cpos;
3920 
3921 	dx_root = (struct ocfs2_dx_root_block *)dx_root_bh->b_data;
3922 
3923 restart_search:
3924 	ret = ocfs2_dx_dir_lookup(dir, &dx_root->dr_list, &lookup->dl_hinfo,
3925 				  &leaf_cpos, &blkno);
3926 	if (ret) {
3927 		mlog_errno(ret);
3928 		goto out;
3929 	}
3930 
3931 	ret = ocfs2_read_dx_leaf(dir, blkno, &dx_leaf_bh);
3932 	if (ret) {
3933 		mlog_errno(ret);
3934 		goto out;
3935 	}
3936 
3937 	dx_leaf = (struct ocfs2_dx_leaf *)dx_leaf_bh->b_data;
3938 
3939 	if (le16_to_cpu(dx_leaf->dl_list.de_num_used) >=
3940 	    le16_to_cpu(dx_leaf->dl_list.de_count)) {
3941 		if (rebalanced) {
3942 			/*
3943 			 * Rebalancing should have provided us with
3944 			 * space in an appropriate leaf.
3945 			 *
3946 			 * XXX: Is this an abnormal condition then?
3947 			 * Should we print a message here?
3948 			 */
3949 			ret = -ENOSPC;
3950 			goto out;
3951 		}
3952 
3953 		ret = ocfs2_dx_dir_rebalance(osb, dir, dx_root_bh, dx_leaf_bh,
3954 					     &lookup->dl_hinfo, leaf_cpos,
3955 					     blkno);
3956 		if (ret) {
3957 			if (ret != -ENOSPC)
3958 				mlog_errno(ret);
3959 			goto out;
3960 		}
3961 
3962 		/*
3963 		 * Restart the lookup. The rebalance might have
3964 		 * changed which block our item fits into. Mark our
3965 		 * progress, so we only execute this once.
3966 		 */
3967 		brelse(dx_leaf_bh);
3968 		dx_leaf_bh = NULL;
3969 		rebalanced = 1;
3970 		goto restart_search;
3971 	}
3972 
3973 	lookup->dl_dx_leaf_bh = dx_leaf_bh;
3974 	dx_leaf_bh = NULL;
3975 
3976 out:
3977 	brelse(dx_leaf_bh);
3978 	return ret;
3979 }
3980 
3981 static int ocfs2_search_dx_free_list(struct inode *dir,
3982 				     struct buffer_head *dx_root_bh,
3983 				     int namelen,
3984 				     struct ocfs2_dir_lookup_result *lookup)
3985 {
3986 	int ret = -ENOSPC;
3987 	struct buffer_head *leaf_bh = NULL, *prev_leaf_bh = NULL;
3988 	struct ocfs2_dir_block_trailer *db;
3989 	u64 next_block;
3990 	int rec_len = OCFS2_DIR_REC_LEN(namelen);
3991 	struct ocfs2_dx_root_block *dx_root;
3992 
3993 	dx_root = (struct ocfs2_dx_root_block *)dx_root_bh->b_data;
3994 	next_block = le64_to_cpu(dx_root->dr_free_blk);
3995 
3996 	while (next_block) {
3997 		brelse(prev_leaf_bh);
3998 		prev_leaf_bh = leaf_bh;
3999 		leaf_bh = NULL;
4000 
4001 		ret = ocfs2_read_dir_block_direct(dir, next_block, &leaf_bh);
4002 		if (ret) {
4003 			mlog_errno(ret);
4004 			goto out;
4005 		}
4006 
4007 		db = ocfs2_trailer_from_bh(leaf_bh, dir->i_sb);
4008 		if (rec_len <= le16_to_cpu(db->db_free_rec_len)) {
4009 			lookup->dl_leaf_bh = leaf_bh;
4010 			lookup->dl_prev_leaf_bh = prev_leaf_bh;
4011 			leaf_bh = NULL;
4012 			prev_leaf_bh = NULL;
4013 			break;
4014 		}
4015 
4016 		next_block = le64_to_cpu(db->db_free_next);
4017 	}
4018 
4019 	if (!next_block)
4020 		ret = -ENOSPC;
4021 
4022 out:
4023 
4024 	brelse(leaf_bh);
4025 	brelse(prev_leaf_bh);
4026 	return ret;
4027 }
4028 
4029 static int ocfs2_expand_inline_dx_root(struct inode *dir,
4030 				       struct buffer_head *dx_root_bh)
4031 {
4032 	int ret, num_dx_leaves, i, j, did_quota = 0;
4033 	struct buffer_head **dx_leaves = NULL;
4034 	struct ocfs2_extent_tree et;
4035 	u64 insert_blkno;
4036 	struct ocfs2_alloc_context *data_ac = NULL;
4037 	struct ocfs2_super *osb = OCFS2_SB(dir->i_sb);
4038 	handle_t *handle = NULL;
4039 	struct ocfs2_dx_root_block *dx_root;
4040 	struct ocfs2_dx_entry_list *entry_list;
4041 	struct ocfs2_dx_entry *dx_entry;
4042 	struct ocfs2_dx_leaf *target_leaf;
4043 
4044 	ret = ocfs2_reserve_clusters(osb, 1, &data_ac);
4045 	if (ret) {
4046 		mlog_errno(ret);
4047 		goto out;
4048 	}
4049 
4050 	dx_leaves = ocfs2_dx_dir_kmalloc_leaves(osb->sb, &num_dx_leaves);
4051 	if (!dx_leaves) {
4052 		ret = -ENOMEM;
4053 		mlog_errno(ret);
4054 		goto out;
4055 	}
4056 
4057 	handle = ocfs2_start_trans(osb, ocfs2_calc_dxi_expand_credits(osb->sb));
4058 	if (IS_ERR(handle)) {
4059 		ret = PTR_ERR(handle);
4060 		mlog_errno(ret);
4061 		goto out;
4062 	}
4063 
4064 	ret = dquot_alloc_space_nodirty(dir,
4065 				       ocfs2_clusters_to_bytes(osb->sb, 1));
4066 	if (ret)
4067 		goto out_commit;
4068 	did_quota = 1;
4069 
4070 	/*
4071 	 * We do this up front, before the allocation, so that a
4072 	 * failure to add the dx_root_bh to the journal won't result
4073 	 * us losing clusters.
4074 	 */
4075 	ret = ocfs2_journal_access_dr(handle, INODE_CACHE(dir), dx_root_bh,
4076 				      OCFS2_JOURNAL_ACCESS_WRITE);
4077 	if (ret) {
4078 		mlog_errno(ret);
4079 		goto out_commit;
4080 	}
4081 
4082 	ret = __ocfs2_dx_dir_new_cluster(dir, 0, handle, data_ac, dx_leaves,
4083 					 num_dx_leaves, &insert_blkno);
4084 	if (ret) {
4085 		mlog_errno(ret);
4086 		goto out_commit;
4087 	}
4088 
4089 	/*
4090 	 * Transfer the entries from our dx_root into the appropriate
4091 	 * block
4092 	 */
4093 	dx_root = (struct ocfs2_dx_root_block *) dx_root_bh->b_data;
4094 	entry_list = &dx_root->dr_entries;
4095 
4096 	for (i = 0; i < le16_to_cpu(entry_list->de_num_used); i++) {
4097 		dx_entry = &entry_list->de_entries[i];
4098 
4099 		j = __ocfs2_dx_dir_hash_idx(osb,
4100 					    le32_to_cpu(dx_entry->dx_minor_hash));
4101 		target_leaf = (struct ocfs2_dx_leaf *)dx_leaves[j]->b_data;
4102 
4103 		ocfs2_dx_dir_leaf_insert_tail(target_leaf, dx_entry);
4104 
4105 		/* Each leaf has been passed to the journal already
4106 		 * via __ocfs2_dx_dir_new_cluster() */
4107 	}
4108 
4109 	dx_root->dr_flags &= ~OCFS2_DX_FLAG_INLINE;
4110 	memset(&dx_root->dr_list, 0, osb->sb->s_blocksize -
4111 	       offsetof(struct ocfs2_dx_root_block, dr_list));
4112 	dx_root->dr_list.l_count =
4113 		cpu_to_le16(ocfs2_extent_recs_per_dx_root(osb->sb));
4114 
4115 	/* This should never fail considering we start with an empty
4116 	 * dx_root. */
4117 	ocfs2_init_dx_root_extent_tree(&et, INODE_CACHE(dir), dx_root_bh);
4118 	ret = ocfs2_insert_extent(handle, &et, 0, insert_blkno, 1, 0, NULL);
4119 	if (ret)
4120 		mlog_errno(ret);
4121 	did_quota = 0;
4122 
4123 	ocfs2_update_inode_fsync_trans(handle, dir, 1);
4124 	ocfs2_journal_dirty(handle, dx_root_bh);
4125 
4126 out_commit:
4127 	if (ret < 0 && did_quota)
4128 		dquot_free_space_nodirty(dir,
4129 					  ocfs2_clusters_to_bytes(dir->i_sb, 1));
4130 
4131 	ocfs2_commit_trans(osb, handle);
4132 
4133 out:
4134 	if (data_ac)
4135 		ocfs2_free_alloc_context(data_ac);
4136 
4137 	if (dx_leaves) {
4138 		for (i = 0; i < num_dx_leaves; i++)
4139 			brelse(dx_leaves[i]);
4140 		kfree(dx_leaves);
4141 	}
4142 	return ret;
4143 }
4144 
4145 static int ocfs2_inline_dx_has_space(struct buffer_head *dx_root_bh)
4146 {
4147 	struct ocfs2_dx_root_block *dx_root;
4148 	struct ocfs2_dx_entry_list *entry_list;
4149 
4150 	dx_root = (struct ocfs2_dx_root_block *) dx_root_bh->b_data;
4151 	entry_list = &dx_root->dr_entries;
4152 
4153 	if (le16_to_cpu(entry_list->de_num_used) >=
4154 	    le16_to_cpu(entry_list->de_count))
4155 		return -ENOSPC;
4156 
4157 	return 0;
4158 }
4159 
4160 static int ocfs2_prepare_dx_dir_for_insert(struct inode *dir,
4161 					   struct buffer_head *di_bh,
4162 					   const char *name,
4163 					   int namelen,
4164 					   struct ocfs2_dir_lookup_result *lookup)
4165 {
4166 	int ret, free_dx_root = 1;
4167 	struct ocfs2_super *osb = OCFS2_SB(dir->i_sb);
4168 	struct buffer_head *dx_root_bh = NULL;
4169 	struct buffer_head *leaf_bh = NULL;
4170 	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
4171 	struct ocfs2_dx_root_block *dx_root;
4172 
4173 	ret = ocfs2_read_dx_root(dir, di, &dx_root_bh);
4174 	if (ret) {
4175 		mlog_errno(ret);
4176 		goto out;
4177 	}
4178 
4179 	dx_root = (struct ocfs2_dx_root_block *)dx_root_bh->b_data;
4180 	if (le32_to_cpu(dx_root->dr_num_entries) == OCFS2_DX_ENTRIES_MAX) {
4181 		ret = -ENOSPC;
4182 		mlog_errno(ret);
4183 		goto out;
4184 	}
4185 
4186 	if (ocfs2_dx_root_inline(dx_root)) {
4187 		ret = ocfs2_inline_dx_has_space(dx_root_bh);
4188 
4189 		if (ret == 0)
4190 			goto search_el;
4191 
4192 		/*
4193 		 * We ran out of room in the root block. Expand it to
4194 		 * an extent, then allow ocfs2_find_dir_space_dx to do
4195 		 * the rest.
4196 		 */
4197 		ret = ocfs2_expand_inline_dx_root(dir, dx_root_bh);
4198 		if (ret) {
4199 			mlog_errno(ret);
4200 			goto out;
4201 		}
4202 	}
4203 
4204 	/*
4205 	 * Insert preparation for an indexed directory is split into two
4206 	 * steps. The call to find_dir_space_dx reserves room in the index for
4207 	 * an additional item. If we run out of space there, it's a real error
4208 	 * we can't continue on.
4209 	 */
4210 	ret = ocfs2_find_dir_space_dx(osb, dir, di_bh, dx_root_bh, name,
4211 				      namelen, lookup);
4212 	if (ret) {
4213 		mlog_errno(ret);
4214 		goto out;
4215 	}
4216 
4217 search_el:
4218 	/*
4219 	 * Next, we need to find space in the unindexed tree. This call
4220 	 * searches using the free space linked list. If the unindexed tree
4221 	 * lacks sufficient space, we'll expand it below. The expansion code
4222 	 * is smart enough to add any new blocks to the free space list.
4223 	 */
4224 	ret = ocfs2_search_dx_free_list(dir, dx_root_bh, namelen, lookup);
4225 	if (ret && ret != -ENOSPC) {
4226 		mlog_errno(ret);
4227 		goto out;
4228 	}
4229 
4230 	/* Do this up here - ocfs2_extend_dir might need the dx_root */
4231 	lookup->dl_dx_root_bh = dx_root_bh;
4232 	free_dx_root = 0;
4233 
4234 	if (ret == -ENOSPC) {
4235 		ret = ocfs2_extend_dir(osb, dir, di_bh, 1, lookup, &leaf_bh);
4236 
4237 		if (ret) {
4238 			mlog_errno(ret);
4239 			goto out;
4240 		}
4241 
4242 		/*
4243 		 * We make the assumption here that new leaf blocks are added
4244 		 * to the front of our free list.
4245 		 */
4246 		lookup->dl_prev_leaf_bh = NULL;
4247 		lookup->dl_leaf_bh = leaf_bh;
4248 	}
4249 
4250 out:
4251 	if (free_dx_root)
4252 		brelse(dx_root_bh);
4253 	return ret;
4254 }
4255 
4256 /*
4257  * Get a directory ready for insert. Any directory allocation required
4258  * happens here. Success returns zero, and enough context in the dir
4259  * lookup result that ocfs2_add_entry() will be able complete the task
4260  * with minimal performance impact.
4261  */
4262 int ocfs2_prepare_dir_for_insert(struct ocfs2_super *osb,
4263 				 struct inode *dir,
4264 				 struct buffer_head *parent_fe_bh,
4265 				 const char *name,
4266 				 int namelen,
4267 				 struct ocfs2_dir_lookup_result *lookup)
4268 {
4269 	int ret;
4270 	unsigned int blocks_wanted = 1;
4271 	struct buffer_head *bh = NULL;
4272 
4273 	trace_ocfs2_prepare_dir_for_insert(
4274 		(unsigned long long)OCFS2_I(dir)->ip_blkno, namelen);
4275 
4276 	if (!namelen) {
4277 		ret = -EINVAL;
4278 		mlog_errno(ret);
4279 		goto out;
4280 	}
4281 
4282 	/*
4283 	 * Do this up front to reduce confusion.
4284 	 *
4285 	 * The directory might start inline, then be turned into an
4286 	 * indexed one, in which case we'd need to hash deep inside
4287 	 * ocfs2_find_dir_space_id(). Since
4288 	 * ocfs2_prepare_dx_dir_for_insert() also needs this hash
4289 	 * done, there seems no point in spreading out the calls. We
4290 	 * can optimize away the case where the file system doesn't
4291 	 * support indexing.
4292 	 */
4293 	if (ocfs2_supports_indexed_dirs(osb))
4294 		ocfs2_dx_dir_name_hash(dir, name, namelen, &lookup->dl_hinfo);
4295 
4296 	if (ocfs2_dir_indexed(dir)) {
4297 		ret = ocfs2_prepare_dx_dir_for_insert(dir, parent_fe_bh,
4298 						      name, namelen, lookup);
4299 		if (ret)
4300 			mlog_errno(ret);
4301 		goto out;
4302 	}
4303 
4304 	if (OCFS2_I(dir)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
4305 		ret = ocfs2_find_dir_space_id(dir, parent_fe_bh, name,
4306 					      namelen, &bh, &blocks_wanted);
4307 	} else
4308 		ret = ocfs2_find_dir_space_el(dir, name, namelen, &bh);
4309 
4310 	if (ret && ret != -ENOSPC) {
4311 		mlog_errno(ret);
4312 		goto out;
4313 	}
4314 
4315 	if (ret == -ENOSPC) {
4316 		/*
4317 		 * We have to expand the directory to add this name.
4318 		 */
4319 		BUG_ON(bh);
4320 
4321 		ret = ocfs2_extend_dir(osb, dir, parent_fe_bh, blocks_wanted,
4322 				       lookup, &bh);
4323 		if (ret) {
4324 			if (ret != -ENOSPC)
4325 				mlog_errno(ret);
4326 			goto out;
4327 		}
4328 
4329 		BUG_ON(!bh);
4330 	}
4331 
4332 	lookup->dl_leaf_bh = bh;
4333 	bh = NULL;
4334 out:
4335 	brelse(bh);
4336 	return ret;
4337 }
4338 
4339 static int ocfs2_dx_dir_remove_index(struct inode *dir,
4340 				     struct buffer_head *di_bh,
4341 				     struct buffer_head *dx_root_bh)
4342 {
4343 	int ret;
4344 	struct ocfs2_super *osb = OCFS2_SB(dir->i_sb);
4345 	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
4346 	struct ocfs2_dx_root_block *dx_root;
4347 	struct inode *dx_alloc_inode = NULL;
4348 	struct buffer_head *dx_alloc_bh = NULL;
4349 	handle_t *handle;
4350 	u64 blk;
4351 	u16 bit;
4352 	u64 bg_blkno;
4353 
4354 	dx_root = (struct ocfs2_dx_root_block *) dx_root_bh->b_data;
4355 
4356 	dx_alloc_inode = ocfs2_get_system_file_inode(osb,
4357 					EXTENT_ALLOC_SYSTEM_INODE,
4358 					le16_to_cpu(dx_root->dr_suballoc_slot));
4359 	if (!dx_alloc_inode) {
4360 		ret = -ENOMEM;
4361 		mlog_errno(ret);
4362 		goto out;
4363 	}
4364 	inode_lock(dx_alloc_inode);
4365 
4366 	ret = ocfs2_inode_lock(dx_alloc_inode, &dx_alloc_bh, 1);
4367 	if (ret) {
4368 		mlog_errno(ret);
4369 		goto out_mutex;
4370 	}
4371 
4372 	handle = ocfs2_start_trans(osb, OCFS2_DX_ROOT_REMOVE_CREDITS);
4373 	if (IS_ERR(handle)) {
4374 		ret = PTR_ERR(handle);
4375 		mlog_errno(ret);
4376 		goto out_unlock;
4377 	}
4378 
4379 	ret = ocfs2_journal_access_di(handle, INODE_CACHE(dir), di_bh,
4380 				      OCFS2_JOURNAL_ACCESS_WRITE);
4381 	if (ret) {
4382 		mlog_errno(ret);
4383 		goto out_commit;
4384 	}
4385 
4386 	spin_lock(&OCFS2_I(dir)->ip_lock);
4387 	OCFS2_I(dir)->ip_dyn_features &= ~OCFS2_INDEXED_DIR_FL;
4388 	di->i_dyn_features = cpu_to_le16(OCFS2_I(dir)->ip_dyn_features);
4389 	spin_unlock(&OCFS2_I(dir)->ip_lock);
4390 	di->i_dx_root = cpu_to_le64(0ULL);
4391 	ocfs2_update_inode_fsync_trans(handle, dir, 1);
4392 
4393 	ocfs2_journal_dirty(handle, di_bh);
4394 
4395 	blk = le64_to_cpu(dx_root->dr_blkno);
4396 	bit = le16_to_cpu(dx_root->dr_suballoc_bit);
4397 	if (dx_root->dr_suballoc_loc)
4398 		bg_blkno = le64_to_cpu(dx_root->dr_suballoc_loc);
4399 	else
4400 		bg_blkno = ocfs2_which_suballoc_group(blk, bit);
4401 	ret = ocfs2_free_suballoc_bits(handle, dx_alloc_inode, dx_alloc_bh,
4402 				       bit, bg_blkno, 1);
4403 	if (ret)
4404 		mlog_errno(ret);
4405 
4406 out_commit:
4407 	ocfs2_commit_trans(osb, handle);
4408 
4409 out_unlock:
4410 	ocfs2_inode_unlock(dx_alloc_inode, 1);
4411 
4412 out_mutex:
4413 	inode_unlock(dx_alloc_inode);
4414 	brelse(dx_alloc_bh);
4415 out:
4416 	iput(dx_alloc_inode);
4417 	return ret;
4418 }
4419 
4420 int ocfs2_dx_dir_truncate(struct inode *dir, struct buffer_head *di_bh)
4421 {
4422 	int ret;
4423 	unsigned int uninitialized_var(clen);
4424 	u32 major_hash = UINT_MAX, p_cpos, uninitialized_var(cpos);
4425 	u64 uninitialized_var(blkno);
4426 	struct ocfs2_super *osb = OCFS2_SB(dir->i_sb);
4427 	struct buffer_head *dx_root_bh = NULL;
4428 	struct ocfs2_dx_root_block *dx_root;
4429 	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
4430 	struct ocfs2_cached_dealloc_ctxt dealloc;
4431 	struct ocfs2_extent_tree et;
4432 
4433 	ocfs2_init_dealloc_ctxt(&dealloc);
4434 
4435 	if (!ocfs2_dir_indexed(dir))
4436 		return 0;
4437 
4438 	ret = ocfs2_read_dx_root(dir, di, &dx_root_bh);
4439 	if (ret) {
4440 		mlog_errno(ret);
4441 		goto out;
4442 	}
4443 	dx_root = (struct ocfs2_dx_root_block *)dx_root_bh->b_data;
4444 
4445 	if (ocfs2_dx_root_inline(dx_root))
4446 		goto remove_index;
4447 
4448 	ocfs2_init_dx_root_extent_tree(&et, INODE_CACHE(dir), dx_root_bh);
4449 
4450 	/* XXX: What if dr_clusters is too large? */
4451 	while (le32_to_cpu(dx_root->dr_clusters)) {
4452 		ret = ocfs2_dx_dir_lookup_rec(dir, &dx_root->dr_list,
4453 					      major_hash, &cpos, &blkno, &clen);
4454 		if (ret) {
4455 			mlog_errno(ret);
4456 			goto out;
4457 		}
4458 
4459 		p_cpos = ocfs2_blocks_to_clusters(dir->i_sb, blkno);
4460 
4461 		ret = ocfs2_remove_btree_range(dir, &et, cpos, p_cpos, clen, 0,
4462 					       &dealloc, 0, false);
4463 		if (ret) {
4464 			mlog_errno(ret);
4465 			goto out;
4466 		}
4467 
4468 		if (cpos == 0)
4469 			break;
4470 
4471 		major_hash = cpos - 1;
4472 	}
4473 
4474 remove_index:
4475 	ret = ocfs2_dx_dir_remove_index(dir, di_bh, dx_root_bh);
4476 	if (ret) {
4477 		mlog_errno(ret);
4478 		goto out;
4479 	}
4480 
4481 	ocfs2_remove_from_cache(INODE_CACHE(dir), dx_root_bh);
4482 out:
4483 	ocfs2_schedule_truncate_log_flush(osb, 1);
4484 	ocfs2_run_deallocs(osb, &dealloc);
4485 
4486 	brelse(dx_root_bh);
4487 	return ret;
4488 }
4489