1/* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
3 *
4 * suballoc.c
5 *
6 * metadata alloc and free
7 * Inspired by ext3 block groups.
8 *
9 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
10 *
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public
13 * License as published by the Free Software Foundation; either
14 * version 2 of the License, or (at your option) any later version.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19 * General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public
22 * License along with this program; if not, write to the
23 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
24 * Boston, MA 021110-1307, USA.
25 */
26
27#include <linux/fs.h>
28#include <linux/types.h>
29#include <linux/slab.h>
30#include <linux/highmem.h>
31
32#include <cluster/masklog.h>
33
34#include "ocfs2.h"
35
36#include "alloc.h"
37#include "blockcheck.h"
38#include "dlmglue.h"
39#include "inode.h"
40#include "journal.h"
41#include "localalloc.h"
42#include "suballoc.h"
43#include "super.h"
44#include "sysfile.h"
45#include "uptodate.h"
46#include "ocfs2_trace.h"
47
48#include "buffer_head_io.h"
49
50#define NOT_ALLOC_NEW_GROUP		0
51#define ALLOC_NEW_GROUP			0x1
52#define ALLOC_GROUPS_FROM_GLOBAL	0x2
53
54#define OCFS2_MAX_TO_STEAL		1024
55
56struct ocfs2_suballoc_result {
57	u64		sr_bg_blkno;	/* The bg we allocated from.  Set
58					   to 0 when a block group is
59					   contiguous. */
60	u64		sr_bg_stable_blkno; /*
61					     * Doesn't change, always
62					     * set to target block
63					     * group descriptor
64					     * block.
65					     */
66	u64		sr_blkno;	/* The first allocated block */
67	unsigned int	sr_bit_offset;	/* The bit in the bg */
68	unsigned int	sr_bits;	/* How many bits we claimed */
69};
70
71static u64 ocfs2_group_from_res(struct ocfs2_suballoc_result *res)
72{
73	if (res->sr_blkno == 0)
74		return 0;
75
76	if (res->sr_bg_blkno)
77		return res->sr_bg_blkno;
78
79	return ocfs2_which_suballoc_group(res->sr_blkno, res->sr_bit_offset);
80}
81
82static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg);
83static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe);
84static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl);
85static int ocfs2_block_group_fill(handle_t *handle,
86				  struct inode *alloc_inode,
87				  struct buffer_head *bg_bh,
88				  u64 group_blkno,
89				  unsigned int group_clusters,
90				  u16 my_chain,
91				  struct ocfs2_chain_list *cl);
92static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
93				   struct inode *alloc_inode,
94				   struct buffer_head *bh,
95				   u64 max_block,
96				   u64 *last_alloc_group,
97				   int flags);
98
99static int ocfs2_cluster_group_search(struct inode *inode,
100				      struct buffer_head *group_bh,
101				      u32 bits_wanted, u32 min_bits,
102				      u64 max_block,
103				      struct ocfs2_suballoc_result *res);
104static int ocfs2_block_group_search(struct inode *inode,
105				    struct buffer_head *group_bh,
106				    u32 bits_wanted, u32 min_bits,
107				    u64 max_block,
108				    struct ocfs2_suballoc_result *res);
109static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
110				     handle_t *handle,
111				     u32 bits_wanted,
112				     u32 min_bits,
113				     struct ocfs2_suballoc_result *res);
114static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
115					 int nr);
116static int ocfs2_relink_block_group(handle_t *handle,
117				    struct inode *alloc_inode,
118				    struct buffer_head *fe_bh,
119				    struct buffer_head *bg_bh,
120				    struct buffer_head *prev_bg_bh,
121				    u16 chain);
122static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
123						     u32 wanted);
124static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
125						   u64 bg_blkno,
126						   u16 bg_bit_off);
127static inline void ocfs2_block_to_cluster_group(struct inode *inode,
128						u64 data_blkno,
129						u64 *bg_blkno,
130						u16 *bg_bit_off);
131static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
132					     u32 bits_wanted, u64 max_block,
133					     int flags,
134					     struct ocfs2_alloc_context **ac);
135
136void ocfs2_free_ac_resource(struct ocfs2_alloc_context *ac)
137{
138	struct inode *inode = ac->ac_inode;
139
140	if (inode) {
141		if (ac->ac_which != OCFS2_AC_USE_LOCAL)
142			ocfs2_inode_unlock(inode, 1);
143
144		mutex_unlock(&inode->i_mutex);
145
146		iput(inode);
147		ac->ac_inode = NULL;
148	}
149	brelse(ac->ac_bh);
150	ac->ac_bh = NULL;
151	ac->ac_resv = NULL;
152	if (ac->ac_find_loc_priv) {
153		kfree(ac->ac_find_loc_priv);
154		ac->ac_find_loc_priv = NULL;
155	}
156}
157
158void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
159{
160	ocfs2_free_ac_resource(ac);
161	kfree(ac);
162}
163
164static u32 ocfs2_bits_per_group(struct ocfs2_chain_list *cl)
165{
166	return (u32)le16_to_cpu(cl->cl_cpg) * (u32)le16_to_cpu(cl->cl_bpc);
167}
168
169#define do_error(fmt, ...)						\
170	do{								\
171		if (resize)					\
172			mlog(ML_ERROR, fmt "\n", ##__VA_ARGS__);	\
173		else							\
174			ocfs2_error(sb, fmt, ##__VA_ARGS__);		\
175	} while (0)
176
177static int ocfs2_validate_gd_self(struct super_block *sb,
178				  struct buffer_head *bh,
179				  int resize)
180{
181	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
182
183	if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
184		do_error("Group descriptor #%llu has bad signature %.*s",
185			 (unsigned long long)bh->b_blocknr, 7,
186			 gd->bg_signature);
187		return -EINVAL;
188	}
189
190	if (le64_to_cpu(gd->bg_blkno) != bh->b_blocknr) {
191		do_error("Group descriptor #%llu has an invalid bg_blkno "
192			 "of %llu",
193			 (unsigned long long)bh->b_blocknr,
194			 (unsigned long long)le64_to_cpu(gd->bg_blkno));
195		return -EINVAL;
196	}
197
198	if (le32_to_cpu(gd->bg_generation) != OCFS2_SB(sb)->fs_generation) {
199		do_error("Group descriptor #%llu has an invalid "
200			 "fs_generation of #%u",
201			 (unsigned long long)bh->b_blocknr,
202			 le32_to_cpu(gd->bg_generation));
203		return -EINVAL;
204	}
205
206	if (le16_to_cpu(gd->bg_free_bits_count) > le16_to_cpu(gd->bg_bits)) {
207		do_error("Group descriptor #%llu has bit count %u but "
208			 "claims that %u are free",
209			 (unsigned long long)bh->b_blocknr,
210			 le16_to_cpu(gd->bg_bits),
211			 le16_to_cpu(gd->bg_free_bits_count));
212		return -EINVAL;
213	}
214
215	if (le16_to_cpu(gd->bg_bits) > (8 * le16_to_cpu(gd->bg_size))) {
216		do_error("Group descriptor #%llu has bit count %u but "
217			 "max bitmap bits of %u",
218			 (unsigned long long)bh->b_blocknr,
219			 le16_to_cpu(gd->bg_bits),
220			 8 * le16_to_cpu(gd->bg_size));
221		return -EINVAL;
222	}
223
224	return 0;
225}
226
227static int ocfs2_validate_gd_parent(struct super_block *sb,
228				    struct ocfs2_dinode *di,
229				    struct buffer_head *bh,
230				    int resize)
231{
232	unsigned int max_bits;
233	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
234
235	if (di->i_blkno != gd->bg_parent_dinode) {
236		do_error("Group descriptor #%llu has bad parent "
237			 "pointer (%llu, expected %llu)",
238			 (unsigned long long)bh->b_blocknr,
239			 (unsigned long long)le64_to_cpu(gd->bg_parent_dinode),
240			 (unsigned long long)le64_to_cpu(di->i_blkno));
241		return -EINVAL;
242	}
243
244	max_bits = le16_to_cpu(di->id2.i_chain.cl_cpg) * le16_to_cpu(di->id2.i_chain.cl_bpc);
245	if (le16_to_cpu(gd->bg_bits) > max_bits) {
246		do_error("Group descriptor #%llu has bit count of %u",
247			 (unsigned long long)bh->b_blocknr,
248			 le16_to_cpu(gd->bg_bits));
249		return -EINVAL;
250	}
251
252	/* In resize, we may meet the case bg_chain == cl_next_free_rec. */
253	if ((le16_to_cpu(gd->bg_chain) >
254	     le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) ||
255	    ((le16_to_cpu(gd->bg_chain) ==
256	     le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) && !resize)) {
257		do_error("Group descriptor #%llu has bad chain %u",
258			 (unsigned long long)bh->b_blocknr,
259			 le16_to_cpu(gd->bg_chain));
260		return -EINVAL;
261	}
262
263	return 0;
264}
265
266#undef do_error
267
268/*
269 * This version only prints errors.  It does not fail the filesystem, and
270 * exists only for resize.
271 */
272int ocfs2_check_group_descriptor(struct super_block *sb,
273				 struct ocfs2_dinode *di,
274				 struct buffer_head *bh)
275{
276	int rc;
277	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
278
279	BUG_ON(!buffer_uptodate(bh));
280
281	/*
282	 * If the ecc fails, we return the error but otherwise
283	 * leave the filesystem running.  We know any error is
284	 * local to this block.
285	 */
286	rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
287	if (rc) {
288		mlog(ML_ERROR,
289		     "Checksum failed for group descriptor %llu\n",
290		     (unsigned long long)bh->b_blocknr);
291	} else
292		rc = ocfs2_validate_gd_self(sb, bh, 1);
293	if (!rc)
294		rc = ocfs2_validate_gd_parent(sb, di, bh, 1);
295
296	return rc;
297}
298
299static int ocfs2_validate_group_descriptor(struct super_block *sb,
300					   struct buffer_head *bh)
301{
302	int rc;
303	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
304
305	trace_ocfs2_validate_group_descriptor(
306					(unsigned long long)bh->b_blocknr);
307
308	BUG_ON(!buffer_uptodate(bh));
309
310	/*
311	 * If the ecc fails, we return the error but otherwise
312	 * leave the filesystem running.  We know any error is
313	 * local to this block.
314	 */
315	rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
316	if (rc)
317		return rc;
318
319	/*
320	 * Errors after here are fatal.
321	 */
322
323	return ocfs2_validate_gd_self(sb, bh, 0);
324}
325
326int ocfs2_read_group_descriptor(struct inode *inode, struct ocfs2_dinode *di,
327				u64 gd_blkno, struct buffer_head **bh)
328{
329	int rc;
330	struct buffer_head *tmp = *bh;
331
332	rc = ocfs2_read_block(INODE_CACHE(inode), gd_blkno, &tmp,
333			      ocfs2_validate_group_descriptor);
334	if (rc)
335		goto out;
336
337	rc = ocfs2_validate_gd_parent(inode->i_sb, di, tmp, 0);
338	if (rc) {
339		brelse(tmp);
340		goto out;
341	}
342
343	/* If ocfs2_read_block() got us a new bh, pass it up. */
344	if (!*bh)
345		*bh = tmp;
346
347out:
348	return rc;
349}
350
351static void ocfs2_bg_discontig_add_extent(struct ocfs2_super *osb,
352					  struct ocfs2_group_desc *bg,
353					  struct ocfs2_chain_list *cl,
354					  u64 p_blkno, unsigned int clusters)
355{
356	struct ocfs2_extent_list *el = &bg->bg_list;
357	struct ocfs2_extent_rec *rec;
358
359	BUG_ON(!ocfs2_supports_discontig_bg(osb));
360	if (!el->l_next_free_rec)
361		el->l_count = cpu_to_le16(ocfs2_extent_recs_per_gd(osb->sb));
362	rec = &el->l_recs[le16_to_cpu(el->l_next_free_rec)];
363	rec->e_blkno = cpu_to_le64(p_blkno);
364	rec->e_cpos = cpu_to_le32(le16_to_cpu(bg->bg_bits) /
365				  le16_to_cpu(cl->cl_bpc));
366	rec->e_leaf_clusters = cpu_to_le16(clusters);
367	le16_add_cpu(&bg->bg_bits, clusters * le16_to_cpu(cl->cl_bpc));
368	le16_add_cpu(&bg->bg_free_bits_count,
369		     clusters * le16_to_cpu(cl->cl_bpc));
370	le16_add_cpu(&el->l_next_free_rec, 1);
371}
372
373static int ocfs2_block_group_fill(handle_t *handle,
374				  struct inode *alloc_inode,
375				  struct buffer_head *bg_bh,
376				  u64 group_blkno,
377				  unsigned int group_clusters,
378				  u16 my_chain,
379				  struct ocfs2_chain_list *cl)
380{
381	int status = 0;
382	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
383	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
384	struct super_block * sb = alloc_inode->i_sb;
385
386	if (((unsigned long long) bg_bh->b_blocknr) != group_blkno) {
387		ocfs2_error(alloc_inode->i_sb, "group block (%llu) != "
388			    "b_blocknr (%llu)",
389			    (unsigned long long)group_blkno,
390			    (unsigned long long) bg_bh->b_blocknr);
391		status = -EIO;
392		goto bail;
393	}
394
395	status = ocfs2_journal_access_gd(handle,
396					 INODE_CACHE(alloc_inode),
397					 bg_bh,
398					 OCFS2_JOURNAL_ACCESS_CREATE);
399	if (status < 0) {
400		mlog_errno(status);
401		goto bail;
402	}
403
404	memset(bg, 0, sb->s_blocksize);
405	strcpy(bg->bg_signature, OCFS2_GROUP_DESC_SIGNATURE);
406	bg->bg_generation = cpu_to_le32(OCFS2_SB(sb)->fs_generation);
407	bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb, 1,
408						osb->s_feature_incompat));
409	bg->bg_chain = cpu_to_le16(my_chain);
410	bg->bg_next_group = cl->cl_recs[my_chain].c_blkno;
411	bg->bg_parent_dinode = cpu_to_le64(OCFS2_I(alloc_inode)->ip_blkno);
412	bg->bg_blkno = cpu_to_le64(group_blkno);
413	if (group_clusters == le16_to_cpu(cl->cl_cpg))
414		bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
415	else
416		ocfs2_bg_discontig_add_extent(osb, bg, cl, group_blkno,
417					      group_clusters);
418
419	/* set the 1st bit in the bitmap to account for the descriptor block */
420	ocfs2_set_bit(0, (unsigned long *)bg->bg_bitmap);
421	bg->bg_free_bits_count = cpu_to_le16(le16_to_cpu(bg->bg_bits) - 1);
422
423	ocfs2_journal_dirty(handle, bg_bh);
424
425	/* There is no need to zero out or otherwise initialize the
426	 * other blocks in a group - All valid FS metadata in a block
427	 * group stores the superblock fs_generation value at
428	 * allocation time. */
429
430bail:
431	if (status)
432		mlog_errno(status);
433	return status;
434}
435
436static inline u16 ocfs2_find_smallest_chain(struct ocfs2_chain_list *cl)
437{
438	u16 curr, best;
439
440	best = curr = 0;
441	while (curr < le16_to_cpu(cl->cl_count)) {
442		if (le32_to_cpu(cl->cl_recs[best].c_total) >
443		    le32_to_cpu(cl->cl_recs[curr].c_total))
444			best = curr;
445		curr++;
446	}
447	return best;
448}
449
450static struct buffer_head *
451ocfs2_block_group_alloc_contig(struct ocfs2_super *osb, handle_t *handle,
452			       struct inode *alloc_inode,
453			       struct ocfs2_alloc_context *ac,
454			       struct ocfs2_chain_list *cl)
455{
456	int status;
457	u32 bit_off, num_bits;
458	u64 bg_blkno;
459	struct buffer_head *bg_bh;
460	unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
461
462	status = ocfs2_claim_clusters(handle, ac,
463				      le16_to_cpu(cl->cl_cpg), &bit_off,
464				      &num_bits);
465	if (status < 0) {
466		if (status != -ENOSPC)
467			mlog_errno(status);
468		goto bail;
469	}
470
471	/* setup the group */
472	bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
473	trace_ocfs2_block_group_alloc_contig(
474	     (unsigned long long)bg_blkno, alloc_rec);
475
476	bg_bh = sb_getblk(osb->sb, bg_blkno);
477	if (!bg_bh) {
478		status = -ENOMEM;
479		mlog_errno(status);
480		goto bail;
481	}
482	ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
483
484	status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
485					bg_blkno, num_bits, alloc_rec, cl);
486	if (status < 0) {
487		brelse(bg_bh);
488		mlog_errno(status);
489	}
490
491bail:
492	return status ? ERR_PTR(status) : bg_bh;
493}
494
495static int ocfs2_block_group_claim_bits(struct ocfs2_super *osb,
496					handle_t *handle,
497					struct ocfs2_alloc_context *ac,
498					unsigned int min_bits,
499					u32 *bit_off, u32 *num_bits)
500{
501	int status = 0;
502
503	while (min_bits) {
504		status = ocfs2_claim_clusters(handle, ac, min_bits,
505					      bit_off, num_bits);
506		if (status != -ENOSPC)
507			break;
508
509		min_bits >>= 1;
510	}
511
512	return status;
513}
514
515static int ocfs2_block_group_grow_discontig(handle_t *handle,
516					    struct inode *alloc_inode,
517					    struct buffer_head *bg_bh,
518					    struct ocfs2_alloc_context *ac,
519					    struct ocfs2_chain_list *cl,
520					    unsigned int min_bits)
521{
522	int status;
523	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
524	struct ocfs2_group_desc *bg =
525		(struct ocfs2_group_desc *)bg_bh->b_data;
526	unsigned int needed = le16_to_cpu(cl->cl_cpg) -
527			 le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
528	u32 p_cpos, clusters;
529	u64 p_blkno;
530	struct ocfs2_extent_list *el = &bg->bg_list;
531
532	status = ocfs2_journal_access_gd(handle,
533					 INODE_CACHE(alloc_inode),
534					 bg_bh,
535					 OCFS2_JOURNAL_ACCESS_CREATE);
536	if (status < 0) {
537		mlog_errno(status);
538		goto bail;
539	}
540
541	while ((needed > 0) && (le16_to_cpu(el->l_next_free_rec) <
542				le16_to_cpu(el->l_count))) {
543		if (min_bits > needed)
544			min_bits = needed;
545		status = ocfs2_block_group_claim_bits(osb, handle, ac,
546						      min_bits, &p_cpos,
547						      &clusters);
548		if (status < 0) {
549			if (status != -ENOSPC)
550				mlog_errno(status);
551			goto bail;
552		}
553		p_blkno = ocfs2_clusters_to_blocks(osb->sb, p_cpos);
554		ocfs2_bg_discontig_add_extent(osb, bg, cl, p_blkno,
555					      clusters);
556
557		min_bits = clusters;
558		needed = le16_to_cpu(cl->cl_cpg) -
559			 le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
560	}
561
562	if (needed > 0) {
563		/*
564		 * We have used up all the extent rec but can't fill up
565		 * the cpg. So bail out.
566		 */
567		status = -ENOSPC;
568		goto bail;
569	}
570
571	ocfs2_journal_dirty(handle, bg_bh);
572
573bail:
574	return status;
575}
576
577static void ocfs2_bg_alloc_cleanup(handle_t *handle,
578				   struct ocfs2_alloc_context *cluster_ac,
579				   struct inode *alloc_inode,
580				   struct buffer_head *bg_bh)
581{
582	int i, ret;
583	struct ocfs2_group_desc *bg;
584	struct ocfs2_extent_list *el;
585	struct ocfs2_extent_rec *rec;
586
587	if (!bg_bh)
588		return;
589
590	bg = (struct ocfs2_group_desc *)bg_bh->b_data;
591	el = &bg->bg_list;
592	for (i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
593		rec = &el->l_recs[i];
594		ret = ocfs2_free_clusters(handle, cluster_ac->ac_inode,
595					  cluster_ac->ac_bh,
596					  le64_to_cpu(rec->e_blkno),
597					  le16_to_cpu(rec->e_leaf_clusters));
598		if (ret)
599			mlog_errno(ret);
600		/* Try all the clusters to free */
601	}
602
603	ocfs2_remove_from_cache(INODE_CACHE(alloc_inode), bg_bh);
604	brelse(bg_bh);
605}
606
607static struct buffer_head *
608ocfs2_block_group_alloc_discontig(handle_t *handle,
609				  struct inode *alloc_inode,
610				  struct ocfs2_alloc_context *ac,
611				  struct ocfs2_chain_list *cl)
612{
613	int status;
614	u32 bit_off, num_bits;
615	u64 bg_blkno;
616	unsigned int min_bits = le16_to_cpu(cl->cl_cpg) >> 1;
617	struct buffer_head *bg_bh = NULL;
618	unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
619	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
620
621	if (!ocfs2_supports_discontig_bg(osb)) {
622		status = -ENOSPC;
623		goto bail;
624	}
625
626	status = ocfs2_extend_trans(handle,
627				    ocfs2_calc_bg_discontig_credits(osb->sb));
628	if (status) {
629		mlog_errno(status);
630		goto bail;
631	}
632
633	/*
634	 * We're going to be grabbing from multiple cluster groups.
635	 * We don't have enough credits to relink them all, and the
636	 * cluster groups will be staying in cache for the duration of
637	 * this operation.
638	 */
639	ac->ac_disable_chain_relink = 1;
640
641	/* Claim the first region */
642	status = ocfs2_block_group_claim_bits(osb, handle, ac, min_bits,
643					      &bit_off, &num_bits);
644	if (status < 0) {
645		if (status != -ENOSPC)
646			mlog_errno(status);
647		goto bail;
648	}
649	min_bits = num_bits;
650
651	/* setup the group */
652	bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
653	trace_ocfs2_block_group_alloc_discontig(
654				(unsigned long long)bg_blkno, alloc_rec);
655
656	bg_bh = sb_getblk(osb->sb, bg_blkno);
657	if (!bg_bh) {
658		status = -ENOMEM;
659		mlog_errno(status);
660		goto bail;
661	}
662	ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
663
664	status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
665					bg_blkno, num_bits, alloc_rec, cl);
666	if (status < 0) {
667		mlog_errno(status);
668		goto bail;
669	}
670
671	status = ocfs2_block_group_grow_discontig(handle, alloc_inode,
672						  bg_bh, ac, cl, min_bits);
673	if (status)
674		mlog_errno(status);
675
676bail:
677	if (status)
678		ocfs2_bg_alloc_cleanup(handle, ac, alloc_inode, bg_bh);
679	return status ? ERR_PTR(status) : bg_bh;
680}
681
682/*
683 * We expect the block group allocator to already be locked.
684 */
685static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
686				   struct inode *alloc_inode,
687				   struct buffer_head *bh,
688				   u64 max_block,
689				   u64 *last_alloc_group,
690				   int flags)
691{
692	int status, credits;
693	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) bh->b_data;
694	struct ocfs2_chain_list *cl;
695	struct ocfs2_alloc_context *ac = NULL;
696	handle_t *handle = NULL;
697	u16 alloc_rec;
698	struct buffer_head *bg_bh = NULL;
699	struct ocfs2_group_desc *bg;
700
701	BUG_ON(ocfs2_is_cluster_bitmap(alloc_inode));
702
703	cl = &fe->id2.i_chain;
704	status = ocfs2_reserve_clusters_with_limit(osb,
705						   le16_to_cpu(cl->cl_cpg),
706						   max_block, flags, &ac);
707	if (status < 0) {
708		if (status != -ENOSPC)
709			mlog_errno(status);
710		goto bail;
711	}
712
713	credits = ocfs2_calc_group_alloc_credits(osb->sb,
714						 le16_to_cpu(cl->cl_cpg));
715	handle = ocfs2_start_trans(osb, credits);
716	if (IS_ERR(handle)) {
717		status = PTR_ERR(handle);
718		handle = NULL;
719		mlog_errno(status);
720		goto bail;
721	}
722
723	if (last_alloc_group && *last_alloc_group != 0) {
724		trace_ocfs2_block_group_alloc(
725				(unsigned long long)*last_alloc_group);
726		ac->ac_last_group = *last_alloc_group;
727	}
728
729	bg_bh = ocfs2_block_group_alloc_contig(osb, handle, alloc_inode,
730					       ac, cl);
731	if (IS_ERR(bg_bh) && (PTR_ERR(bg_bh) == -ENOSPC))
732		bg_bh = ocfs2_block_group_alloc_discontig(handle,
733							  alloc_inode,
734							  ac, cl);
735	if (IS_ERR(bg_bh)) {
736		status = PTR_ERR(bg_bh);
737		bg_bh = NULL;
738		if (status != -ENOSPC)
739			mlog_errno(status);
740		goto bail;
741	}
742	bg = (struct ocfs2_group_desc *) bg_bh->b_data;
743
744	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
745					 bh, OCFS2_JOURNAL_ACCESS_WRITE);
746	if (status < 0) {
747		mlog_errno(status);
748		goto bail;
749	}
750
751	alloc_rec = le16_to_cpu(bg->bg_chain);
752	le32_add_cpu(&cl->cl_recs[alloc_rec].c_free,
753		     le16_to_cpu(bg->bg_free_bits_count));
754	le32_add_cpu(&cl->cl_recs[alloc_rec].c_total,
755		     le16_to_cpu(bg->bg_bits));
756	cl->cl_recs[alloc_rec].c_blkno = bg->bg_blkno;
757	if (le16_to_cpu(cl->cl_next_free_rec) < le16_to_cpu(cl->cl_count))
758		le16_add_cpu(&cl->cl_next_free_rec, 1);
759
760	le32_add_cpu(&fe->id1.bitmap1.i_used, le16_to_cpu(bg->bg_bits) -
761					le16_to_cpu(bg->bg_free_bits_count));
762	le32_add_cpu(&fe->id1.bitmap1.i_total, le16_to_cpu(bg->bg_bits));
763	le32_add_cpu(&fe->i_clusters, le16_to_cpu(cl->cl_cpg));
764
765	ocfs2_journal_dirty(handle, bh);
766
767	spin_lock(&OCFS2_I(alloc_inode)->ip_lock);
768	OCFS2_I(alloc_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
769	fe->i_size = cpu_to_le64(ocfs2_clusters_to_bytes(alloc_inode->i_sb,
770					     le32_to_cpu(fe->i_clusters)));
771	spin_unlock(&OCFS2_I(alloc_inode)->ip_lock);
772	i_size_write(alloc_inode, le64_to_cpu(fe->i_size));
773	alloc_inode->i_blocks = ocfs2_inode_sector_count(alloc_inode);
774	ocfs2_update_inode_fsync_trans(handle, alloc_inode, 0);
775
776	status = 0;
777
778	/* save the new last alloc group so that the caller can cache it. */
779	if (last_alloc_group)
780		*last_alloc_group = ac->ac_last_group;
781
782bail:
783	if (handle)
784		ocfs2_commit_trans(osb, handle);
785
786	if (ac)
787		ocfs2_free_alloc_context(ac);
788
789	brelse(bg_bh);
790
791	if (status)
792		mlog_errno(status);
793	return status;
794}
795
796static int ocfs2_reserve_suballoc_bits(struct ocfs2_super *osb,
797				       struct ocfs2_alloc_context *ac,
798				       int type,
799				       u32 slot,
800				       u64 *last_alloc_group,
801				       int flags)
802{
803	int status;
804	u32 bits_wanted = ac->ac_bits_wanted;
805	struct inode *alloc_inode;
806	struct buffer_head *bh = NULL;
807	struct ocfs2_dinode *fe;
808	u32 free_bits;
809
810	alloc_inode = ocfs2_get_system_file_inode(osb, type, slot);
811	if (!alloc_inode) {
812		mlog_errno(-EINVAL);
813		return -EINVAL;
814	}
815
816	mutex_lock(&alloc_inode->i_mutex);
817
818	status = ocfs2_inode_lock(alloc_inode, &bh, 1);
819	if (status < 0) {
820		mutex_unlock(&alloc_inode->i_mutex);
821		iput(alloc_inode);
822
823		mlog_errno(status);
824		return status;
825	}
826
827	ac->ac_inode = alloc_inode;
828	ac->ac_alloc_slot = slot;
829
830	fe = (struct ocfs2_dinode *) bh->b_data;
831
832	/* The bh was validated by the inode read inside
833	 * ocfs2_inode_lock().  Any corruption is a code bug. */
834	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
835
836	if (!(fe->i_flags & cpu_to_le32(OCFS2_CHAIN_FL))) {
837		ocfs2_error(alloc_inode->i_sb, "Invalid chain allocator %llu",
838			    (unsigned long long)le64_to_cpu(fe->i_blkno));
839		status = -EIO;
840		goto bail;
841	}
842
843	free_bits = le32_to_cpu(fe->id1.bitmap1.i_total) -
844		le32_to_cpu(fe->id1.bitmap1.i_used);
845
846	if (bits_wanted > free_bits) {
847		/* cluster bitmap never grows */
848		if (ocfs2_is_cluster_bitmap(alloc_inode)) {
849			trace_ocfs2_reserve_suballoc_bits_nospc(bits_wanted,
850								free_bits);
851			status = -ENOSPC;
852			goto bail;
853		}
854
855		if (!(flags & ALLOC_NEW_GROUP)) {
856			trace_ocfs2_reserve_suballoc_bits_no_new_group(
857						slot, bits_wanted, free_bits);
858			status = -ENOSPC;
859			goto bail;
860		}
861
862		status = ocfs2_block_group_alloc(osb, alloc_inode, bh,
863						 ac->ac_max_block,
864						 last_alloc_group, flags);
865		if (status < 0) {
866			if (status != -ENOSPC)
867				mlog_errno(status);
868			goto bail;
869		}
870		atomic_inc(&osb->alloc_stats.bg_extends);
871
872		/* You should never ask for this much metadata */
873		BUG_ON(bits_wanted >
874		       (le32_to_cpu(fe->id1.bitmap1.i_total)
875			- le32_to_cpu(fe->id1.bitmap1.i_used)));
876	}
877
878	get_bh(bh);
879	ac->ac_bh = bh;
880bail:
881	brelse(bh);
882
883	if (status)
884		mlog_errno(status);
885	return status;
886}
887
888static void ocfs2_init_inode_steal_slot(struct ocfs2_super *osb)
889{
890	spin_lock(&osb->osb_lock);
891	osb->s_inode_steal_slot = OCFS2_INVALID_SLOT;
892	spin_unlock(&osb->osb_lock);
893	atomic_set(&osb->s_num_inodes_stolen, 0);
894}
895
896static void ocfs2_init_meta_steal_slot(struct ocfs2_super *osb)
897{
898	spin_lock(&osb->osb_lock);
899	osb->s_meta_steal_slot = OCFS2_INVALID_SLOT;
900	spin_unlock(&osb->osb_lock);
901	atomic_set(&osb->s_num_meta_stolen, 0);
902}
903
904void ocfs2_init_steal_slots(struct ocfs2_super *osb)
905{
906	ocfs2_init_inode_steal_slot(osb);
907	ocfs2_init_meta_steal_slot(osb);
908}
909
910static void __ocfs2_set_steal_slot(struct ocfs2_super *osb, int slot, int type)
911{
912	spin_lock(&osb->osb_lock);
913	if (type == INODE_ALLOC_SYSTEM_INODE)
914		osb->s_inode_steal_slot = slot;
915	else if (type == EXTENT_ALLOC_SYSTEM_INODE)
916		osb->s_meta_steal_slot = slot;
917	spin_unlock(&osb->osb_lock);
918}
919
920static int __ocfs2_get_steal_slot(struct ocfs2_super *osb, int type)
921{
922	int slot = OCFS2_INVALID_SLOT;
923
924	spin_lock(&osb->osb_lock);
925	if (type == INODE_ALLOC_SYSTEM_INODE)
926		slot = osb->s_inode_steal_slot;
927	else if (type == EXTENT_ALLOC_SYSTEM_INODE)
928		slot = osb->s_meta_steal_slot;
929	spin_unlock(&osb->osb_lock);
930
931	return slot;
932}
933
934static int ocfs2_get_inode_steal_slot(struct ocfs2_super *osb)
935{
936	return __ocfs2_get_steal_slot(osb, INODE_ALLOC_SYSTEM_INODE);
937}
938
939static int ocfs2_get_meta_steal_slot(struct ocfs2_super *osb)
940{
941	return __ocfs2_get_steal_slot(osb, EXTENT_ALLOC_SYSTEM_INODE);
942}
943
944static int ocfs2_steal_resource(struct ocfs2_super *osb,
945				struct ocfs2_alloc_context *ac,
946				int type)
947{
948	int i, status = -ENOSPC;
949	int slot = __ocfs2_get_steal_slot(osb, type);
950
951	/* Start to steal resource from the first slot after ours. */
952	if (slot == OCFS2_INVALID_SLOT)
953		slot = osb->slot_num + 1;
954
955	for (i = 0; i < osb->max_slots; i++, slot++) {
956		if (slot == osb->max_slots)
957			slot = 0;
958
959		if (slot == osb->slot_num)
960			continue;
961
962		status = ocfs2_reserve_suballoc_bits(osb, ac,
963						     type,
964						     (u32)slot, NULL,
965						     NOT_ALLOC_NEW_GROUP);
966		if (status >= 0) {
967			__ocfs2_set_steal_slot(osb, slot, type);
968			break;
969		}
970
971		ocfs2_free_ac_resource(ac);
972	}
973
974	return status;
975}
976
977static int ocfs2_steal_inode(struct ocfs2_super *osb,
978			     struct ocfs2_alloc_context *ac)
979{
980	return ocfs2_steal_resource(osb, ac, INODE_ALLOC_SYSTEM_INODE);
981}
982
983static int ocfs2_steal_meta(struct ocfs2_super *osb,
984			    struct ocfs2_alloc_context *ac)
985{
986	return ocfs2_steal_resource(osb, ac, EXTENT_ALLOC_SYSTEM_INODE);
987}
988
989int ocfs2_reserve_new_metadata_blocks(struct ocfs2_super *osb,
990				      int blocks,
991				      struct ocfs2_alloc_context **ac)
992{
993	int status;
994	int slot = ocfs2_get_meta_steal_slot(osb);
995
996	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
997	if (!(*ac)) {
998		status = -ENOMEM;
999		mlog_errno(status);
1000		goto bail;
1001	}
1002
1003	(*ac)->ac_bits_wanted = blocks;
1004	(*ac)->ac_which = OCFS2_AC_USE_META;
1005	(*ac)->ac_group_search = ocfs2_block_group_search;
1006
1007	if (slot != OCFS2_INVALID_SLOT &&
1008		atomic_read(&osb->s_num_meta_stolen) < OCFS2_MAX_TO_STEAL)
1009		goto extent_steal;
1010
1011	atomic_set(&osb->s_num_meta_stolen, 0);
1012	status = ocfs2_reserve_suballoc_bits(osb, (*ac),
1013					     EXTENT_ALLOC_SYSTEM_INODE,
1014					     (u32)osb->slot_num, NULL,
1015					     ALLOC_GROUPS_FROM_GLOBAL|ALLOC_NEW_GROUP);
1016
1017
1018	if (status >= 0) {
1019		status = 0;
1020		if (slot != OCFS2_INVALID_SLOT)
1021			ocfs2_init_meta_steal_slot(osb);
1022		goto bail;
1023	} else if (status < 0 && status != -ENOSPC) {
1024		mlog_errno(status);
1025		goto bail;
1026	}
1027
1028	ocfs2_free_ac_resource(*ac);
1029
1030extent_steal:
1031	status = ocfs2_steal_meta(osb, *ac);
1032	atomic_inc(&osb->s_num_meta_stolen);
1033	if (status < 0) {
1034		if (status != -ENOSPC)
1035			mlog_errno(status);
1036		goto bail;
1037	}
1038
1039	status = 0;
1040bail:
1041	if ((status < 0) && *ac) {
1042		ocfs2_free_alloc_context(*ac);
1043		*ac = NULL;
1044	}
1045
1046	if (status)
1047		mlog_errno(status);
1048	return status;
1049}
1050
1051int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
1052			       struct ocfs2_extent_list *root_el,
1053			       struct ocfs2_alloc_context **ac)
1054{
1055	return ocfs2_reserve_new_metadata_blocks(osb,
1056					ocfs2_extend_meta_needed(root_el),
1057					ac);
1058}
1059
1060int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
1061			    struct ocfs2_alloc_context **ac)
1062{
1063	int status;
1064	int slot = ocfs2_get_inode_steal_slot(osb);
1065	u64 alloc_group;
1066
1067	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1068	if (!(*ac)) {
1069		status = -ENOMEM;
1070		mlog_errno(status);
1071		goto bail;
1072	}
1073
1074	(*ac)->ac_bits_wanted = 1;
1075	(*ac)->ac_which = OCFS2_AC_USE_INODE;
1076
1077	(*ac)->ac_group_search = ocfs2_block_group_search;
1078
1079	/*
1080	 * stat(2) can't handle i_ino > 32bits, so we tell the
1081	 * lower levels not to allocate us a block group past that
1082	 * limit.  The 'inode64' mount option avoids this behavior.
1083	 */
1084	if (!(osb->s_mount_opt & OCFS2_MOUNT_INODE64))
1085		(*ac)->ac_max_block = (u32)~0U;
1086
1087	/*
1088	 * slot is set when we successfully steal inode from other nodes.
1089	 * It is reset in 3 places:
1090	 * 1. when we flush the truncate log
1091	 * 2. when we complete local alloc recovery.
1092	 * 3. when we successfully allocate from our own slot.
1093	 * After it is set, we will go on stealing inodes until we find the
1094	 * need to check our slots to see whether there is some space for us.
1095	 */
1096	if (slot != OCFS2_INVALID_SLOT &&
1097	    atomic_read(&osb->s_num_inodes_stolen) < OCFS2_MAX_TO_STEAL)
1098		goto inode_steal;
1099
1100	atomic_set(&osb->s_num_inodes_stolen, 0);
1101	alloc_group = osb->osb_inode_alloc_group;
1102	status = ocfs2_reserve_suballoc_bits(osb, *ac,
1103					     INODE_ALLOC_SYSTEM_INODE,
1104					     (u32)osb->slot_num,
1105					     &alloc_group,
1106					     ALLOC_NEW_GROUP |
1107					     ALLOC_GROUPS_FROM_GLOBAL);
1108	if (status >= 0) {
1109		status = 0;
1110
1111		spin_lock(&osb->osb_lock);
1112		osb->osb_inode_alloc_group = alloc_group;
1113		spin_unlock(&osb->osb_lock);
1114		trace_ocfs2_reserve_new_inode_new_group(
1115			(unsigned long long)alloc_group);
1116
1117		/*
1118		 * Some inodes must be freed by us, so try to allocate
1119		 * from our own next time.
1120		 */
1121		if (slot != OCFS2_INVALID_SLOT)
1122			ocfs2_init_inode_steal_slot(osb);
1123		goto bail;
1124	} else if (status < 0 && status != -ENOSPC) {
1125		mlog_errno(status);
1126		goto bail;
1127	}
1128
1129	ocfs2_free_ac_resource(*ac);
1130
1131inode_steal:
1132	status = ocfs2_steal_inode(osb, *ac);
1133	atomic_inc(&osb->s_num_inodes_stolen);
1134	if (status < 0) {
1135		if (status != -ENOSPC)
1136			mlog_errno(status);
1137		goto bail;
1138	}
1139
1140	status = 0;
1141bail:
1142	if ((status < 0) && *ac) {
1143		ocfs2_free_alloc_context(*ac);
1144		*ac = NULL;
1145	}
1146
1147	if (status)
1148		mlog_errno(status);
1149	return status;
1150}
1151
1152/* local alloc code has to do the same thing, so rather than do this
1153 * twice.. */
1154int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
1155				      struct ocfs2_alloc_context *ac)
1156{
1157	int status;
1158
1159	ac->ac_which = OCFS2_AC_USE_MAIN;
1160	ac->ac_group_search = ocfs2_cluster_group_search;
1161
1162	status = ocfs2_reserve_suballoc_bits(osb, ac,
1163					     GLOBAL_BITMAP_SYSTEM_INODE,
1164					     OCFS2_INVALID_SLOT, NULL,
1165					     ALLOC_NEW_GROUP);
1166	if (status < 0 && status != -ENOSPC) {
1167		mlog_errno(status);
1168		goto bail;
1169	}
1170
1171bail:
1172	return status;
1173}
1174
1175/* Callers don't need to care which bitmap (local alloc or main) to
1176 * use so we figure it out for them, but unfortunately this clutters
1177 * things a bit. */
1178static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
1179					     u32 bits_wanted, u64 max_block,
1180					     int flags,
1181					     struct ocfs2_alloc_context **ac)
1182{
1183	int status;
1184
1185	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1186	if (!(*ac)) {
1187		status = -ENOMEM;
1188		mlog_errno(status);
1189		goto bail;
1190	}
1191
1192	(*ac)->ac_bits_wanted = bits_wanted;
1193	(*ac)->ac_max_block = max_block;
1194
1195	status = -ENOSPC;
1196	if (!(flags & ALLOC_GROUPS_FROM_GLOBAL) &&
1197	    ocfs2_alloc_should_use_local(osb, bits_wanted)) {
1198		status = ocfs2_reserve_local_alloc_bits(osb,
1199							bits_wanted,
1200							*ac);
1201		if ((status < 0) && (status != -ENOSPC)) {
1202			mlog_errno(status);
1203			goto bail;
1204		}
1205	}
1206
1207	if (status == -ENOSPC) {
1208		status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
1209		if (status < 0) {
1210			if (status != -ENOSPC)
1211				mlog_errno(status);
1212			goto bail;
1213		}
1214	}
1215
1216	status = 0;
1217bail:
1218	if ((status < 0) && *ac) {
1219		ocfs2_free_alloc_context(*ac);
1220		*ac = NULL;
1221	}
1222
1223	if (status)
1224		mlog_errno(status);
1225	return status;
1226}
1227
1228int ocfs2_reserve_clusters(struct ocfs2_super *osb,
1229			   u32 bits_wanted,
1230			   struct ocfs2_alloc_context **ac)
1231{
1232	return ocfs2_reserve_clusters_with_limit(osb, bits_wanted, 0,
1233						 ALLOC_NEW_GROUP, ac);
1234}
1235
1236/*
1237 * More or less lifted from ext3. I'll leave their description below:
1238 *
1239 * "For ext3 allocations, we must not reuse any blocks which are
1240 * allocated in the bitmap buffer's "last committed data" copy.  This
1241 * prevents deletes from freeing up the page for reuse until we have
1242 * committed the delete transaction.
1243 *
1244 * If we didn't do this, then deleting something and reallocating it as
1245 * data would allow the old block to be overwritten before the
1246 * transaction committed (because we force data to disk before commit).
1247 * This would lead to corruption if we crashed between overwriting the
1248 * data and committing the delete.
1249 *
1250 * @@@ We may want to make this allocation behaviour conditional on
1251 * data-writes at some point, and disable it for metadata allocations or
1252 * sync-data inodes."
1253 *
1254 * Note: OCFS2 already does this differently for metadata vs data
1255 * allocations, as those bitmaps are separate and undo access is never
1256 * called on a metadata group descriptor.
1257 */
1258static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
1259					 int nr)
1260{
1261	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1262	int ret;
1263
1264	if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
1265		return 0;
1266
1267	if (!buffer_jbd(bg_bh))
1268		return 1;
1269
1270	jbd_lock_bh_state(bg_bh);
1271	bg = (struct ocfs2_group_desc *) bh2jh(bg_bh)->b_committed_data;
1272	if (bg)
1273		ret = !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
1274	else
1275		ret = 1;
1276	jbd_unlock_bh_state(bg_bh);
1277
1278	return ret;
1279}
1280
1281static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
1282					     struct buffer_head *bg_bh,
1283					     unsigned int bits_wanted,
1284					     unsigned int total_bits,
1285					     struct ocfs2_suballoc_result *res)
1286{
1287	void *bitmap;
1288	u16 best_offset, best_size;
1289	int offset, start, found, status = 0;
1290	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1291
1292	/* Callers got this descriptor from
1293	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1294	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1295
1296	found = start = best_offset = best_size = 0;
1297	bitmap = bg->bg_bitmap;
1298
1299	while((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) != -1) {
1300		if (offset == total_bits)
1301			break;
1302
1303		if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
1304			/* We found a zero, but we can't use it as it
1305			 * hasn't been put to disk yet! */
1306			found = 0;
1307			start = offset + 1;
1308		} else if (offset == start) {
1309			/* we found a zero */
1310			found++;
1311			/* move start to the next bit to test */
1312			start++;
1313		} else {
1314			/* got a zero after some ones */
1315			found = 1;
1316			start = offset + 1;
1317		}
1318		if (found > best_size) {
1319			best_size = found;
1320			best_offset = start - found;
1321		}
1322		/* we got everything we needed */
1323		if (found == bits_wanted) {
1324			/* mlog(0, "Found it all!\n"); */
1325			break;
1326		}
1327	}
1328
1329	if (best_size) {
1330		res->sr_bit_offset = best_offset;
1331		res->sr_bits = best_size;
1332	} else {
1333		status = -ENOSPC;
1334		/* No error log here -- see the comment above
1335		 * ocfs2_test_bg_bit_allocatable */
1336	}
1337
1338	return status;
1339}
1340
1341int ocfs2_block_group_set_bits(handle_t *handle,
1342					     struct inode *alloc_inode,
1343					     struct ocfs2_group_desc *bg,
1344					     struct buffer_head *group_bh,
1345					     unsigned int bit_off,
1346					     unsigned int num_bits)
1347{
1348	int status;
1349	void *bitmap = bg->bg_bitmap;
1350	int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1351
1352	/* All callers get the descriptor via
1353	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1354	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1355	BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
1356
1357	trace_ocfs2_block_group_set_bits(bit_off, num_bits);
1358
1359	if (ocfs2_is_cluster_bitmap(alloc_inode))
1360		journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1361
1362	status = ocfs2_journal_access_gd(handle,
1363					 INODE_CACHE(alloc_inode),
1364					 group_bh,
1365					 journal_type);
1366	if (status < 0) {
1367		mlog_errno(status);
1368		goto bail;
1369	}
1370
1371	le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
1372	if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
1373		ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit"
1374			    " count %u but claims %u are freed. num_bits %d",
1375			    (unsigned long long)le64_to_cpu(bg->bg_blkno),
1376			    le16_to_cpu(bg->bg_bits),
1377			    le16_to_cpu(bg->bg_free_bits_count), num_bits);
1378		return -EROFS;
1379	}
1380	while(num_bits--)
1381		ocfs2_set_bit(bit_off++, bitmap);
1382
1383	ocfs2_journal_dirty(handle, group_bh);
1384
1385bail:
1386	return status;
1387}
1388
1389/* find the one with the most empty bits */
1390static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
1391{
1392	u16 curr, best;
1393
1394	BUG_ON(!cl->cl_next_free_rec);
1395
1396	best = curr = 0;
1397	while (curr < le16_to_cpu(cl->cl_next_free_rec)) {
1398		if (le32_to_cpu(cl->cl_recs[curr].c_free) >
1399		    le32_to_cpu(cl->cl_recs[best].c_free))
1400			best = curr;
1401		curr++;
1402	}
1403
1404	BUG_ON(best >= le16_to_cpu(cl->cl_next_free_rec));
1405	return best;
1406}
1407
1408static int ocfs2_relink_block_group(handle_t *handle,
1409				    struct inode *alloc_inode,
1410				    struct buffer_head *fe_bh,
1411				    struct buffer_head *bg_bh,
1412				    struct buffer_head *prev_bg_bh,
1413				    u16 chain)
1414{
1415	int status;
1416	/* there is a really tiny chance the journal calls could fail,
1417	 * but we wouldn't want inconsistent blocks in *any* case. */
1418	u64 bg_ptr, prev_bg_ptr;
1419	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
1420	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1421	struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
1422
1423	/* The caller got these descriptors from
1424	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1425	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1426	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(prev_bg));
1427
1428	trace_ocfs2_relink_block_group(
1429		(unsigned long long)le64_to_cpu(fe->i_blkno), chain,
1430		(unsigned long long)le64_to_cpu(bg->bg_blkno),
1431		(unsigned long long)le64_to_cpu(prev_bg->bg_blkno));
1432
1433	bg_ptr = le64_to_cpu(bg->bg_next_group);
1434	prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
1435
1436	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1437					 prev_bg_bh,
1438					 OCFS2_JOURNAL_ACCESS_WRITE);
1439	if (status < 0)
1440		goto out;
1441
1442	prev_bg->bg_next_group = bg->bg_next_group;
1443	ocfs2_journal_dirty(handle, prev_bg_bh);
1444
1445	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1446					 bg_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1447	if (status < 0)
1448		goto out_rollback_prev_bg;
1449
1450	bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
1451	ocfs2_journal_dirty(handle, bg_bh);
1452
1453	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
1454					 fe_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1455	if (status < 0)
1456		goto out_rollback_bg;
1457
1458	fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
1459	ocfs2_journal_dirty(handle, fe_bh);
1460
1461out:
1462	if (status < 0)
1463		mlog_errno(status);
1464	return status;
1465
1466out_rollback_bg:
1467	bg->bg_next_group = cpu_to_le64(bg_ptr);
1468out_rollback_prev_bg:
1469	prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
1470	goto out;
1471}
1472
1473static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
1474						     u32 wanted)
1475{
1476	return le16_to_cpu(bg->bg_free_bits_count) > wanted;
1477}
1478
1479/* return 0 on success, -ENOSPC to keep searching and any other < 0
1480 * value on error. */
1481static int ocfs2_cluster_group_search(struct inode *inode,
1482				      struct buffer_head *group_bh,
1483				      u32 bits_wanted, u32 min_bits,
1484				      u64 max_block,
1485				      struct ocfs2_suballoc_result *res)
1486{
1487	int search = -ENOSPC;
1488	int ret;
1489	u64 blkoff;
1490	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
1491	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1492	unsigned int max_bits, gd_cluster_off;
1493
1494	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1495
1496	if (gd->bg_free_bits_count) {
1497		max_bits = le16_to_cpu(gd->bg_bits);
1498
1499		/* Tail groups in cluster bitmaps which aren't cpg
1500		 * aligned are prone to partial extension by a failed
1501		 * fs resize. If the file system resize never got to
1502		 * update the dinode cluster count, then we don't want
1503		 * to trust any clusters past it, regardless of what
1504		 * the group descriptor says. */
1505		gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
1506							  le64_to_cpu(gd->bg_blkno));
1507		if ((gd_cluster_off + max_bits) >
1508		    OCFS2_I(inode)->ip_clusters) {
1509			max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
1510			trace_ocfs2_cluster_group_search_wrong_max_bits(
1511				(unsigned long long)le64_to_cpu(gd->bg_blkno),
1512				le16_to_cpu(gd->bg_bits),
1513				OCFS2_I(inode)->ip_clusters, max_bits);
1514		}
1515
1516		ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1517							group_bh, bits_wanted,
1518							max_bits, res);
1519		if (ret)
1520			return ret;
1521
1522		if (max_block) {
1523			blkoff = ocfs2_clusters_to_blocks(inode->i_sb,
1524							  gd_cluster_off +
1525							  res->sr_bit_offset +
1526							  res->sr_bits);
1527			trace_ocfs2_cluster_group_search_max_block(
1528				(unsigned long long)blkoff,
1529				(unsigned long long)max_block);
1530			if (blkoff > max_block)
1531				return -ENOSPC;
1532		}
1533
1534		/* ocfs2_block_group_find_clear_bits() might
1535		 * return success, but we still want to return
1536		 * -ENOSPC unless it found the minimum number
1537		 * of bits. */
1538		if (min_bits <= res->sr_bits)
1539			search = 0; /* success */
1540		else if (res->sr_bits) {
1541			/*
1542			 * Don't show bits which we'll be returning
1543			 * for allocation to the local alloc bitmap.
1544			 */
1545			ocfs2_local_alloc_seen_free_bits(osb, res->sr_bits);
1546		}
1547	}
1548
1549	return search;
1550}
1551
1552static int ocfs2_block_group_search(struct inode *inode,
1553				    struct buffer_head *group_bh,
1554				    u32 bits_wanted, u32 min_bits,
1555				    u64 max_block,
1556				    struct ocfs2_suballoc_result *res)
1557{
1558	int ret = -ENOSPC;
1559	u64 blkoff;
1560	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
1561
1562	BUG_ON(min_bits != 1);
1563	BUG_ON(ocfs2_is_cluster_bitmap(inode));
1564
1565	if (bg->bg_free_bits_count) {
1566		ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1567							group_bh, bits_wanted,
1568							le16_to_cpu(bg->bg_bits),
1569							res);
1570		if (!ret && max_block) {
1571			blkoff = le64_to_cpu(bg->bg_blkno) +
1572				res->sr_bit_offset + res->sr_bits;
1573			trace_ocfs2_block_group_search_max_block(
1574				(unsigned long long)blkoff,
1575				(unsigned long long)max_block);
1576			if (blkoff > max_block)
1577				ret = -ENOSPC;
1578		}
1579	}
1580
1581	return ret;
1582}
1583
1584int ocfs2_alloc_dinode_update_counts(struct inode *inode,
1585				       handle_t *handle,
1586				       struct buffer_head *di_bh,
1587				       u32 num_bits,
1588				       u16 chain)
1589{
1590	int ret;
1591	u32 tmp_used;
1592	struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1593	struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &di->id2.i_chain;
1594
1595	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
1596				      OCFS2_JOURNAL_ACCESS_WRITE);
1597	if (ret < 0) {
1598		mlog_errno(ret);
1599		goto out;
1600	}
1601
1602	tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1603	di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
1604	le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
1605	ocfs2_journal_dirty(handle, di_bh);
1606
1607out:
1608	return ret;
1609}
1610
1611void ocfs2_rollback_alloc_dinode_counts(struct inode *inode,
1612				       struct buffer_head *di_bh,
1613				       u32 num_bits,
1614				       u16 chain)
1615{
1616	u32 tmp_used;
1617	struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1618	struct ocfs2_chain_list *cl;
1619
1620	cl = (struct ocfs2_chain_list *)&di->id2.i_chain;
1621	tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1622	di->id1.bitmap1.i_used = cpu_to_le32(tmp_used - num_bits);
1623	le32_add_cpu(&cl->cl_recs[chain].c_free, num_bits);
1624}
1625
1626static int ocfs2_bg_discontig_fix_by_rec(struct ocfs2_suballoc_result *res,
1627					 struct ocfs2_extent_rec *rec,
1628					 struct ocfs2_chain_list *cl)
1629{
1630	unsigned int bpc = le16_to_cpu(cl->cl_bpc);
1631	unsigned int bitoff = le32_to_cpu(rec->e_cpos) * bpc;
1632	unsigned int bitcount = le16_to_cpu(rec->e_leaf_clusters) * bpc;
1633
1634	if (res->sr_bit_offset < bitoff)
1635		return 0;
1636	if (res->sr_bit_offset >= (bitoff + bitcount))
1637		return 0;
1638	res->sr_blkno = le64_to_cpu(rec->e_blkno) +
1639		(res->sr_bit_offset - bitoff);
1640	if ((res->sr_bit_offset + res->sr_bits) > (bitoff + bitcount))
1641		res->sr_bits = (bitoff + bitcount) - res->sr_bit_offset;
1642	return 1;
1643}
1644
1645static void ocfs2_bg_discontig_fix_result(struct ocfs2_alloc_context *ac,
1646					  struct ocfs2_group_desc *bg,
1647					  struct ocfs2_suballoc_result *res)
1648{
1649	int i;
1650	u64 bg_blkno = res->sr_bg_blkno;  /* Save off */
1651	struct ocfs2_extent_rec *rec;
1652	struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1653	struct ocfs2_chain_list *cl = &di->id2.i_chain;
1654
1655	if (ocfs2_is_cluster_bitmap(ac->ac_inode)) {
1656		res->sr_blkno = 0;
1657		return;
1658	}
1659
1660	res->sr_blkno = res->sr_bg_blkno + res->sr_bit_offset;
1661	res->sr_bg_blkno = 0;  /* Clear it for contig block groups */
1662	if (!ocfs2_supports_discontig_bg(OCFS2_SB(ac->ac_inode->i_sb)) ||
1663	    !bg->bg_list.l_next_free_rec)
1664		return;
1665
1666	for (i = 0; i < le16_to_cpu(bg->bg_list.l_next_free_rec); i++) {
1667		rec = &bg->bg_list.l_recs[i];
1668		if (ocfs2_bg_discontig_fix_by_rec(res, rec, cl)) {
1669			res->sr_bg_blkno = bg_blkno;  /* Restore */
1670			break;
1671		}
1672	}
1673}
1674
1675static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
1676				  handle_t *handle,
1677				  u32 bits_wanted,
1678				  u32 min_bits,
1679				  struct ocfs2_suballoc_result *res,
1680				  u16 *bits_left)
1681{
1682	int ret;
1683	struct buffer_head *group_bh = NULL;
1684	struct ocfs2_group_desc *gd;
1685	struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1686	struct inode *alloc_inode = ac->ac_inode;
1687
1688	ret = ocfs2_read_group_descriptor(alloc_inode, di,
1689					  res->sr_bg_blkno, &group_bh);
1690	if (ret < 0) {
1691		mlog_errno(ret);
1692		return ret;
1693	}
1694
1695	gd = (struct ocfs2_group_desc *) group_bh->b_data;
1696	ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
1697				  ac->ac_max_block, res);
1698	if (ret < 0) {
1699		if (ret != -ENOSPC)
1700			mlog_errno(ret);
1701		goto out;
1702	}
1703
1704	if (!ret)
1705		ocfs2_bg_discontig_fix_result(ac, gd, res);
1706
1707	/*
1708	 * sr_bg_blkno might have been changed by
1709	 * ocfs2_bg_discontig_fix_result
1710	 */
1711	res->sr_bg_stable_blkno = group_bh->b_blocknr;
1712
1713	if (ac->ac_find_loc_only)
1714		goto out_loc_only;
1715
1716	ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
1717					       res->sr_bits,
1718					       le16_to_cpu(gd->bg_chain));
1719	if (ret < 0) {
1720		mlog_errno(ret);
1721		goto out;
1722	}
1723
1724	ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
1725					 res->sr_bit_offset, res->sr_bits);
1726	if (ret < 0) {
1727		ocfs2_rollback_alloc_dinode_counts(alloc_inode, ac->ac_bh,
1728					       res->sr_bits,
1729					       le16_to_cpu(gd->bg_chain));
1730		mlog_errno(ret);
1731	}
1732
1733out_loc_only:
1734	*bits_left = le16_to_cpu(gd->bg_free_bits_count);
1735
1736out:
1737	brelse(group_bh);
1738
1739	return ret;
1740}
1741
1742static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
1743			      handle_t *handle,
1744			      u32 bits_wanted,
1745			      u32 min_bits,
1746			      struct ocfs2_suballoc_result *res,
1747			      u16 *bits_left)
1748{
1749	int status;
1750	u16 chain;
1751	u64 next_group;
1752	struct inode *alloc_inode = ac->ac_inode;
1753	struct buffer_head *group_bh = NULL;
1754	struct buffer_head *prev_group_bh = NULL;
1755	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1756	struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1757	struct ocfs2_group_desc *bg;
1758
1759	chain = ac->ac_chain;
1760	trace_ocfs2_search_chain_begin(
1761		(unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
1762		bits_wanted, chain);
1763
1764	status = ocfs2_read_group_descriptor(alloc_inode, fe,
1765					     le64_to_cpu(cl->cl_recs[chain].c_blkno),
1766					     &group_bh);
1767	if (status < 0) {
1768		mlog_errno(status);
1769		goto bail;
1770	}
1771	bg = (struct ocfs2_group_desc *) group_bh->b_data;
1772
1773	status = -ENOSPC;
1774	/* for now, the chain search is a bit simplistic. We just use
1775	 * the 1st group with any empty bits. */
1776	while ((status = ac->ac_group_search(alloc_inode, group_bh,
1777					     bits_wanted, min_bits,
1778					     ac->ac_max_block,
1779					     res)) == -ENOSPC) {
1780		if (!bg->bg_next_group)
1781			break;
1782
1783		brelse(prev_group_bh);
1784		prev_group_bh = NULL;
1785
1786		next_group = le64_to_cpu(bg->bg_next_group);
1787		prev_group_bh = group_bh;
1788		group_bh = NULL;
1789		status = ocfs2_read_group_descriptor(alloc_inode, fe,
1790						     next_group, &group_bh);
1791		if (status < 0) {
1792			mlog_errno(status);
1793			goto bail;
1794		}
1795		bg = (struct ocfs2_group_desc *) group_bh->b_data;
1796	}
1797	if (status < 0) {
1798		if (status != -ENOSPC)
1799			mlog_errno(status);
1800		goto bail;
1801	}
1802
1803	trace_ocfs2_search_chain_succ(
1804		(unsigned long long)le64_to_cpu(bg->bg_blkno), res->sr_bits);
1805
1806	res->sr_bg_blkno = le64_to_cpu(bg->bg_blkno);
1807
1808	BUG_ON(res->sr_bits == 0);
1809	if (!status)
1810		ocfs2_bg_discontig_fix_result(ac, bg, res);
1811
1812	/*
1813	 * sr_bg_blkno might have been changed by
1814	 * ocfs2_bg_discontig_fix_result
1815	 */
1816	res->sr_bg_stable_blkno = group_bh->b_blocknr;
1817
1818	/*
1819	 * Keep track of previous block descriptor read. When
1820	 * we find a target, if we have read more than X
1821	 * number of descriptors, and the target is reasonably
1822	 * empty, relink him to top of his chain.
1823	 *
1824	 * We've read 0 extra blocks and only send one more to
1825	 * the transaction, yet the next guy to search has a
1826	 * much easier time.
1827	 *
1828	 * Do this *after* figuring out how many bits we're taking out
1829	 * of our target group.
1830	 */
1831	if (!ac->ac_disable_chain_relink &&
1832	    (prev_group_bh) &&
1833	    (ocfs2_block_group_reasonably_empty(bg, res->sr_bits))) {
1834		status = ocfs2_relink_block_group(handle, alloc_inode,
1835						  ac->ac_bh, group_bh,
1836						  prev_group_bh, chain);
1837		if (status < 0) {
1838			mlog_errno(status);
1839			goto bail;
1840		}
1841	}
1842
1843	if (ac->ac_find_loc_only)
1844		goto out_loc_only;
1845
1846	status = ocfs2_alloc_dinode_update_counts(alloc_inode, handle,
1847						  ac->ac_bh, res->sr_bits,
1848						  chain);
1849	if (status) {
1850		mlog_errno(status);
1851		goto bail;
1852	}
1853
1854	status = ocfs2_block_group_set_bits(handle,
1855					    alloc_inode,
1856					    bg,
1857					    group_bh,
1858					    res->sr_bit_offset,
1859					    res->sr_bits);
1860	if (status < 0) {
1861		ocfs2_rollback_alloc_dinode_counts(alloc_inode,
1862					ac->ac_bh, res->sr_bits, chain);
1863		mlog_errno(status);
1864		goto bail;
1865	}
1866
1867	trace_ocfs2_search_chain_end(
1868			(unsigned long long)le64_to_cpu(fe->i_blkno),
1869			res->sr_bits);
1870
1871out_loc_only:
1872	*bits_left = le16_to_cpu(bg->bg_free_bits_count);
1873bail:
1874	brelse(group_bh);
1875	brelse(prev_group_bh);
1876
1877	if (status)
1878		mlog_errno(status);
1879	return status;
1880}
1881
1882/* will give out up to bits_wanted contiguous bits. */
1883static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
1884				     handle_t *handle,
1885				     u32 bits_wanted,
1886				     u32 min_bits,
1887				     struct ocfs2_suballoc_result *res)
1888{
1889	int status;
1890	u16 victim, i;
1891	u16 bits_left = 0;
1892	u64 hint = ac->ac_last_group;
1893	struct ocfs2_chain_list *cl;
1894	struct ocfs2_dinode *fe;
1895
1896	BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1897	BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1898	BUG_ON(!ac->ac_bh);
1899
1900	fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1901
1902	/* The bh was validated by the inode read during
1903	 * ocfs2_reserve_suballoc_bits().  Any corruption is a code bug. */
1904	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
1905
1906	if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1907	    le32_to_cpu(fe->id1.bitmap1.i_total)) {
1908		ocfs2_error(ac->ac_inode->i_sb,
1909			    "Chain allocator dinode %llu has %u used "
1910			    "bits but only %u total.",
1911			    (unsigned long long)le64_to_cpu(fe->i_blkno),
1912			    le32_to_cpu(fe->id1.bitmap1.i_used),
1913			    le32_to_cpu(fe->id1.bitmap1.i_total));
1914		status = -EIO;
1915		goto bail;
1916	}
1917
1918	res->sr_bg_blkno = hint;
1919	if (res->sr_bg_blkno) {
1920		/* Attempt to short-circuit the usual search mechanism
1921		 * by jumping straight to the most recently used
1922		 * allocation group. This helps us maintain some
1923		 * contiguousness across allocations. */
1924		status = ocfs2_search_one_group(ac, handle, bits_wanted,
1925						min_bits, res, &bits_left);
1926		if (!status)
1927			goto set_hint;
1928		if (status < 0 && status != -ENOSPC) {
1929			mlog_errno(status);
1930			goto bail;
1931		}
1932	}
1933
1934	cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1935
1936	victim = ocfs2_find_victim_chain(cl);
1937	ac->ac_chain = victim;
1938
1939	status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1940				    res, &bits_left);
1941	if (!status) {
1942		hint = ocfs2_group_from_res(res);
1943		goto set_hint;
1944	}
1945	if (status < 0 && status != -ENOSPC) {
1946		mlog_errno(status);
1947		goto bail;
1948	}
1949
1950	trace_ocfs2_claim_suballoc_bits(victim);
1951
1952	/* If we didn't pick a good victim, then just default to
1953	 * searching each chain in order. Don't allow chain relinking
1954	 * because we only calculate enough journal credits for one
1955	 * relink per alloc. */
1956	ac->ac_disable_chain_relink = 1;
1957	for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
1958		if (i == victim)
1959			continue;
1960		if (!cl->cl_recs[i].c_free)
1961			continue;
1962
1963		ac->ac_chain = i;
1964		status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1965					    res, &bits_left);
1966		if (!status) {
1967			hint = ocfs2_group_from_res(res);
1968			break;
1969		}
1970		if (status < 0 && status != -ENOSPC) {
1971			mlog_errno(status);
1972			goto bail;
1973		}
1974	}
1975
1976set_hint:
1977	if (status != -ENOSPC) {
1978		/* If the next search of this group is not likely to
1979		 * yield a suitable extent, then we reset the last
1980		 * group hint so as to not waste a disk read */
1981		if (bits_left < min_bits)
1982			ac->ac_last_group = 0;
1983		else
1984			ac->ac_last_group = hint;
1985	}
1986
1987bail:
1988	if (status)
1989		mlog_errno(status);
1990	return status;
1991}
1992
1993int ocfs2_claim_metadata(handle_t *handle,
1994			 struct ocfs2_alloc_context *ac,
1995			 u32 bits_wanted,
1996			 u64 *suballoc_loc,
1997			 u16 *suballoc_bit_start,
1998			 unsigned int *num_bits,
1999			 u64 *blkno_start)
2000{
2001	int status;
2002	struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
2003
2004	BUG_ON(!ac);
2005	BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
2006	BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
2007
2008	status = ocfs2_claim_suballoc_bits(ac,
2009					   handle,
2010					   bits_wanted,
2011					   1,
2012					   &res);
2013	if (status < 0) {
2014		mlog_errno(status);
2015		goto bail;
2016	}
2017	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2018
2019	*suballoc_loc = res.sr_bg_blkno;
2020	*suballoc_bit_start = res.sr_bit_offset;
2021	*blkno_start = res.sr_blkno;
2022	ac->ac_bits_given += res.sr_bits;
2023	*num_bits = res.sr_bits;
2024	status = 0;
2025bail:
2026	if (status)
2027		mlog_errno(status);
2028	return status;
2029}
2030
2031static void ocfs2_init_inode_ac_group(struct inode *dir,
2032				      struct buffer_head *parent_di_bh,
2033				      struct ocfs2_alloc_context *ac)
2034{
2035	struct ocfs2_dinode *di = (struct ocfs2_dinode *)parent_di_bh->b_data;
2036	/*
2037	 * Try to allocate inodes from some specific group.
2038	 *
2039	 * If the parent dir has recorded the last group used in allocation,
2040	 * cool, use it. Otherwise if we try to allocate new inode from the
2041	 * same slot the parent dir belongs to, use the same chunk.
2042	 *
2043	 * We are very careful here to avoid the mistake of setting
2044	 * ac_last_group to a group descriptor from a different (unlocked) slot.
2045	 */
2046	if (OCFS2_I(dir)->ip_last_used_group &&
2047	    OCFS2_I(dir)->ip_last_used_slot == ac->ac_alloc_slot)
2048		ac->ac_last_group = OCFS2_I(dir)->ip_last_used_group;
2049	else if (le16_to_cpu(di->i_suballoc_slot) == ac->ac_alloc_slot) {
2050		if (di->i_suballoc_loc)
2051			ac->ac_last_group = le64_to_cpu(di->i_suballoc_loc);
2052		else
2053			ac->ac_last_group = ocfs2_which_suballoc_group(
2054					le64_to_cpu(di->i_blkno),
2055					le16_to_cpu(di->i_suballoc_bit));
2056	}
2057}
2058
2059static inline void ocfs2_save_inode_ac_group(struct inode *dir,
2060					     struct ocfs2_alloc_context *ac)
2061{
2062	OCFS2_I(dir)->ip_last_used_group = ac->ac_last_group;
2063	OCFS2_I(dir)->ip_last_used_slot = ac->ac_alloc_slot;
2064}
2065
2066int ocfs2_find_new_inode_loc(struct inode *dir,
2067			     struct buffer_head *parent_fe_bh,
2068			     struct ocfs2_alloc_context *ac,
2069			     u64 *fe_blkno)
2070{
2071	int ret;
2072	handle_t *handle = NULL;
2073	struct ocfs2_suballoc_result *res;
2074
2075	BUG_ON(!ac);
2076	BUG_ON(ac->ac_bits_given != 0);
2077	BUG_ON(ac->ac_bits_wanted != 1);
2078	BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2079
2080	res = kzalloc(sizeof(*res), GFP_NOFS);
2081	if (res == NULL) {
2082		ret = -ENOMEM;
2083		mlog_errno(ret);
2084		goto out;
2085	}
2086
2087	ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2088
2089	/*
2090	 * The handle started here is for chain relink. Alternatively,
2091	 * we could just disable relink for these calls.
2092	 */
2093	handle = ocfs2_start_trans(OCFS2_SB(dir->i_sb), OCFS2_SUBALLOC_ALLOC);
2094	if (IS_ERR(handle)) {
2095		ret = PTR_ERR(handle);
2096		handle = NULL;
2097		mlog_errno(ret);
2098		goto out;
2099	}
2100
2101	/*
2102	 * This will instruct ocfs2_claim_suballoc_bits and
2103	 * ocfs2_search_one_group to search but save actual allocation
2104	 * for later.
2105	 */
2106	ac->ac_find_loc_only = 1;
2107
2108	ret = ocfs2_claim_suballoc_bits(ac, handle, 1, 1, res);
2109	if (ret < 0) {
2110		mlog_errno(ret);
2111		goto out;
2112	}
2113
2114	ac->ac_find_loc_priv = res;
2115	*fe_blkno = res->sr_blkno;
2116	ocfs2_update_inode_fsync_trans(handle, dir, 0);
2117out:
2118	if (handle)
2119		ocfs2_commit_trans(OCFS2_SB(dir->i_sb), handle);
2120
2121	if (ret)
2122		kfree(res);
2123
2124	return ret;
2125}
2126
2127int ocfs2_claim_new_inode_at_loc(handle_t *handle,
2128				 struct inode *dir,
2129				 struct ocfs2_alloc_context *ac,
2130				 u64 *suballoc_loc,
2131				 u16 *suballoc_bit,
2132				 u64 di_blkno)
2133{
2134	int ret;
2135	u16 chain;
2136	struct ocfs2_suballoc_result *res = ac->ac_find_loc_priv;
2137	struct buffer_head *bg_bh = NULL;
2138	struct ocfs2_group_desc *bg;
2139	struct ocfs2_dinode *di = (struct ocfs2_dinode *) ac->ac_bh->b_data;
2140
2141	/*
2142	 * Since di_blkno is being passed back in, we check for any
2143	 * inconsistencies which may have happened between
2144	 * calls. These are code bugs as di_blkno is not expected to
2145	 * change once returned from ocfs2_find_new_inode_loc()
2146	 */
2147	BUG_ON(res->sr_blkno != di_blkno);
2148
2149	ret = ocfs2_read_group_descriptor(ac->ac_inode, di,
2150					  res->sr_bg_stable_blkno, &bg_bh);
2151	if (ret) {
2152		mlog_errno(ret);
2153		goto out;
2154	}
2155
2156	bg = (struct ocfs2_group_desc *) bg_bh->b_data;
2157	chain = le16_to_cpu(bg->bg_chain);
2158
2159	ret = ocfs2_alloc_dinode_update_counts(ac->ac_inode, handle,
2160					       ac->ac_bh, res->sr_bits,
2161					       chain);
2162	if (ret) {
2163		mlog_errno(ret);
2164		goto out;
2165	}
2166
2167	ret = ocfs2_block_group_set_bits(handle,
2168					 ac->ac_inode,
2169					 bg,
2170					 bg_bh,
2171					 res->sr_bit_offset,
2172					 res->sr_bits);
2173	if (ret < 0) {
2174		ocfs2_rollback_alloc_dinode_counts(ac->ac_inode,
2175					       ac->ac_bh, res->sr_bits, chain);
2176		mlog_errno(ret);
2177		goto out;
2178	}
2179
2180	trace_ocfs2_claim_new_inode_at_loc((unsigned long long)di_blkno,
2181					   res->sr_bits);
2182
2183	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2184
2185	BUG_ON(res->sr_bits != 1);
2186
2187	*suballoc_loc = res->sr_bg_blkno;
2188	*suballoc_bit = res->sr_bit_offset;
2189	ac->ac_bits_given++;
2190	ocfs2_save_inode_ac_group(dir, ac);
2191
2192out:
2193	brelse(bg_bh);
2194
2195	return ret;
2196}
2197
2198int ocfs2_claim_new_inode(handle_t *handle,
2199			  struct inode *dir,
2200			  struct buffer_head *parent_fe_bh,
2201			  struct ocfs2_alloc_context *ac,
2202			  u64 *suballoc_loc,
2203			  u16 *suballoc_bit,
2204			  u64 *fe_blkno)
2205{
2206	int status;
2207	struct ocfs2_suballoc_result res;
2208
2209	BUG_ON(!ac);
2210	BUG_ON(ac->ac_bits_given != 0);
2211	BUG_ON(ac->ac_bits_wanted != 1);
2212	BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2213
2214	ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2215
2216	status = ocfs2_claim_suballoc_bits(ac,
2217					   handle,
2218					   1,
2219					   1,
2220					   &res);
2221	if (status < 0) {
2222		mlog_errno(status);
2223		goto bail;
2224	}
2225	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2226
2227	BUG_ON(res.sr_bits != 1);
2228
2229	*suballoc_loc = res.sr_bg_blkno;
2230	*suballoc_bit = res.sr_bit_offset;
2231	*fe_blkno = res.sr_blkno;
2232	ac->ac_bits_given++;
2233	ocfs2_save_inode_ac_group(dir, ac);
2234	status = 0;
2235bail:
2236	if (status)
2237		mlog_errno(status);
2238	return status;
2239}
2240
2241/* translate a group desc. blkno and it's bitmap offset into
2242 * disk cluster offset. */
2243static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
2244						   u64 bg_blkno,
2245						   u16 bg_bit_off)
2246{
2247	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2248	u32 cluster = 0;
2249
2250	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2251
2252	if (bg_blkno != osb->first_cluster_group_blkno)
2253		cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
2254	cluster += (u32) bg_bit_off;
2255	return cluster;
2256}
2257
2258/* given a cluster offset, calculate which block group it belongs to
2259 * and return that block offset. */
2260u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster)
2261{
2262	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2263	u32 group_no;
2264
2265	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2266
2267	group_no = cluster / osb->bitmap_cpg;
2268	if (!group_no)
2269		return osb->first_cluster_group_blkno;
2270	return ocfs2_clusters_to_blocks(inode->i_sb,
2271					group_no * osb->bitmap_cpg);
2272}
2273
2274/* given the block number of a cluster start, calculate which cluster
2275 * group and descriptor bitmap offset that corresponds to. */
2276static inline void ocfs2_block_to_cluster_group(struct inode *inode,
2277						u64 data_blkno,
2278						u64 *bg_blkno,
2279						u16 *bg_bit_off)
2280{
2281	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2282	u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
2283
2284	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2285
2286	*bg_blkno = ocfs2_which_cluster_group(inode,
2287					      data_cluster);
2288
2289	if (*bg_blkno == osb->first_cluster_group_blkno)
2290		*bg_bit_off = (u16) data_cluster;
2291	else
2292		*bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
2293							     data_blkno - *bg_blkno);
2294}
2295
2296/*
2297 * min_bits - minimum contiguous chunk from this total allocation we
2298 * can handle. set to what we asked for originally for a full
2299 * contig. allocation, set to '1' to indicate we can deal with extents
2300 * of any size.
2301 */
2302int __ocfs2_claim_clusters(handle_t *handle,
2303			   struct ocfs2_alloc_context *ac,
2304			   u32 min_clusters,
2305			   u32 max_clusters,
2306			   u32 *cluster_start,
2307			   u32 *num_clusters)
2308{
2309	int status;
2310	unsigned int bits_wanted = max_clusters;
2311	struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
2312	struct ocfs2_super *osb = OCFS2_SB(ac->ac_inode->i_sb);
2313
2314	BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
2315
2316	BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
2317	       && ac->ac_which != OCFS2_AC_USE_MAIN);
2318
2319	if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
2320		WARN_ON(min_clusters > 1);
2321
2322		status = ocfs2_claim_local_alloc_bits(osb,
2323						      handle,
2324						      ac,
2325						      bits_wanted,
2326						      cluster_start,
2327						      num_clusters);
2328		if (!status)
2329			atomic_inc(&osb->alloc_stats.local_data);
2330	} else {
2331		if (min_clusters > (osb->bitmap_cpg - 1)) {
2332			/* The only paths asking for contiguousness
2333			 * should know about this already. */
2334			mlog(ML_ERROR, "minimum allocation requested %u exceeds "
2335			     "group bitmap size %u!\n", min_clusters,
2336			     osb->bitmap_cpg);
2337			status = -ENOSPC;
2338			goto bail;
2339		}
2340		/* clamp the current request down to a realistic size. */
2341		if (bits_wanted > (osb->bitmap_cpg - 1))
2342			bits_wanted = osb->bitmap_cpg - 1;
2343
2344		status = ocfs2_claim_suballoc_bits(ac,
2345						   handle,
2346						   bits_wanted,
2347						   min_clusters,
2348						   &res);
2349		if (!status) {
2350			BUG_ON(res.sr_blkno); /* cluster alloc can't set */
2351			*cluster_start =
2352				ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
2353								 res.sr_bg_blkno,
2354								 res.sr_bit_offset);
2355			atomic_inc(&osb->alloc_stats.bitmap_data);
2356			*num_clusters = res.sr_bits;
2357		}
2358	}
2359	if (status < 0) {
2360		if (status != -ENOSPC)
2361			mlog_errno(status);
2362		goto bail;
2363	}
2364
2365	ac->ac_bits_given += *num_clusters;
2366
2367bail:
2368	if (status)
2369		mlog_errno(status);
2370	return status;
2371}
2372
2373int ocfs2_claim_clusters(handle_t *handle,
2374			 struct ocfs2_alloc_context *ac,
2375			 u32 min_clusters,
2376			 u32 *cluster_start,
2377			 u32 *num_clusters)
2378{
2379	unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
2380
2381	return __ocfs2_claim_clusters(handle, ac, min_clusters,
2382				      bits_wanted, cluster_start, num_clusters);
2383}
2384
2385static int ocfs2_block_group_clear_bits(handle_t *handle,
2386					struct inode *alloc_inode,
2387					struct ocfs2_group_desc *bg,
2388					struct buffer_head *group_bh,
2389					unsigned int bit_off,
2390					unsigned int num_bits,
2391					void (*undo_fn)(unsigned int bit,
2392							unsigned long *bmap))
2393{
2394	int status;
2395	unsigned int tmp;
2396	struct ocfs2_group_desc *undo_bg = NULL;
2397
2398	/* The caller got this descriptor from
2399	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
2400	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
2401
2402	trace_ocfs2_block_group_clear_bits(bit_off, num_bits);
2403
2404	BUG_ON(undo_fn && !ocfs2_is_cluster_bitmap(alloc_inode));
2405	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
2406					 group_bh,
2407					 undo_fn ?
2408					 OCFS2_JOURNAL_ACCESS_UNDO :
2409					 OCFS2_JOURNAL_ACCESS_WRITE);
2410	if (status < 0) {
2411		mlog_errno(status);
2412		goto bail;
2413	}
2414
2415	if (undo_fn) {
2416		jbd_lock_bh_state(group_bh);
2417		undo_bg = (struct ocfs2_group_desc *)
2418					bh2jh(group_bh)->b_committed_data;
2419		BUG_ON(!undo_bg);
2420	}
2421
2422	tmp = num_bits;
2423	while(tmp--) {
2424		ocfs2_clear_bit((bit_off + tmp),
2425				(unsigned long *) bg->bg_bitmap);
2426		if (undo_fn)
2427			undo_fn(bit_off + tmp,
2428				(unsigned long *) undo_bg->bg_bitmap);
2429	}
2430	le16_add_cpu(&bg->bg_free_bits_count, num_bits);
2431	if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
2432		ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit"
2433			    " count %u but claims %u are freed. num_bits %d",
2434			    (unsigned long long)le64_to_cpu(bg->bg_blkno),
2435			    le16_to_cpu(bg->bg_bits),
2436			    le16_to_cpu(bg->bg_free_bits_count), num_bits);
2437		return -EROFS;
2438	}
2439
2440	if (undo_fn)
2441		jbd_unlock_bh_state(group_bh);
2442
2443	ocfs2_journal_dirty(handle, group_bh);
2444bail:
2445	return status;
2446}
2447
2448/*
2449 * expects the suballoc inode to already be locked.
2450 */
2451static int _ocfs2_free_suballoc_bits(handle_t *handle,
2452				     struct inode *alloc_inode,
2453				     struct buffer_head *alloc_bh,
2454				     unsigned int start_bit,
2455				     u64 bg_blkno,
2456				     unsigned int count,
2457				     void (*undo_fn)(unsigned int bit,
2458						     unsigned long *bitmap))
2459{
2460	int status = 0;
2461	u32 tmp_used;
2462	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
2463	struct ocfs2_chain_list *cl = &fe->id2.i_chain;
2464	struct buffer_head *group_bh = NULL;
2465	struct ocfs2_group_desc *group;
2466
2467	/* The alloc_bh comes from ocfs2_free_dinode() or
2468	 * ocfs2_free_clusters().  The callers have all locked the
2469	 * allocator and gotten alloc_bh from the lock call.  This
2470	 * validates the dinode buffer.  Any corruption that has happened
2471	 * is a code bug. */
2472	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
2473	BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
2474
2475	trace_ocfs2_free_suballoc_bits(
2476		(unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
2477		(unsigned long long)bg_blkno,
2478		start_bit, count);
2479
2480	status = ocfs2_read_group_descriptor(alloc_inode, fe, bg_blkno,
2481					     &group_bh);
2482	if (status < 0) {
2483		mlog_errno(status);
2484		goto bail;
2485	}
2486	group = (struct ocfs2_group_desc *) group_bh->b_data;
2487
2488	BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
2489
2490	status = ocfs2_block_group_clear_bits(handle, alloc_inode,
2491					      group, group_bh,
2492					      start_bit, count, undo_fn);
2493	if (status < 0) {
2494		mlog_errno(status);
2495		goto bail;
2496	}
2497
2498	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
2499					 alloc_bh, OCFS2_JOURNAL_ACCESS_WRITE);
2500	if (status < 0) {
2501		mlog_errno(status);
2502		ocfs2_block_group_set_bits(handle, alloc_inode, group, group_bh,
2503				start_bit, count);
2504		goto bail;
2505	}
2506
2507	le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
2508		     count);
2509	tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
2510	fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
2511	ocfs2_journal_dirty(handle, alloc_bh);
2512
2513bail:
2514	brelse(group_bh);
2515
2516	if (status)
2517		mlog_errno(status);
2518	return status;
2519}
2520
2521int ocfs2_free_suballoc_bits(handle_t *handle,
2522			     struct inode *alloc_inode,
2523			     struct buffer_head *alloc_bh,
2524			     unsigned int start_bit,
2525			     u64 bg_blkno,
2526			     unsigned int count)
2527{
2528	return _ocfs2_free_suballoc_bits(handle, alloc_inode, alloc_bh,
2529					 start_bit, bg_blkno, count, NULL);
2530}
2531
2532int ocfs2_free_dinode(handle_t *handle,
2533		      struct inode *inode_alloc_inode,
2534		      struct buffer_head *inode_alloc_bh,
2535		      struct ocfs2_dinode *di)
2536{
2537	u64 blk = le64_to_cpu(di->i_blkno);
2538	u16 bit = le16_to_cpu(di->i_suballoc_bit);
2539	u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
2540
2541	if (di->i_suballoc_loc)
2542		bg_blkno = le64_to_cpu(di->i_suballoc_loc);
2543	return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
2544					inode_alloc_bh, bit, bg_blkno, 1);
2545}
2546
2547static int _ocfs2_free_clusters(handle_t *handle,
2548				struct inode *bitmap_inode,
2549				struct buffer_head *bitmap_bh,
2550				u64 start_blk,
2551				unsigned int num_clusters,
2552				void (*undo_fn)(unsigned int bit,
2553						unsigned long *bitmap))
2554{
2555	int status;
2556	u16 bg_start_bit;
2557	u64 bg_blkno;
2558	struct ocfs2_dinode *fe;
2559
2560	/* You can't ever have a contiguous set of clusters
2561	 * bigger than a block group bitmap so we never have to worry
2562	 * about looping on them.
2563	 * This is expensive. We can safely remove once this stuff has
2564	 * gotten tested really well. */
2565	BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb, ocfs2_blocks_to_clusters(bitmap_inode->i_sb, start_blk)));
2566
2567	fe = (struct ocfs2_dinode *) bitmap_bh->b_data;
2568
2569	ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
2570				     &bg_start_bit);
2571
2572	trace_ocfs2_free_clusters((unsigned long long)bg_blkno,
2573			(unsigned long long)start_blk,
2574			bg_start_bit, num_clusters);
2575
2576	status = _ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
2577					   bg_start_bit, bg_blkno,
2578					   num_clusters, undo_fn);
2579	if (status < 0) {
2580		mlog_errno(status);
2581		goto out;
2582	}
2583
2584	ocfs2_local_alloc_seen_free_bits(OCFS2_SB(bitmap_inode->i_sb),
2585					 num_clusters);
2586
2587out:
2588	if (status)
2589		mlog_errno(status);
2590	return status;
2591}
2592
2593int ocfs2_free_clusters(handle_t *handle,
2594			struct inode *bitmap_inode,
2595			struct buffer_head *bitmap_bh,
2596			u64 start_blk,
2597			unsigned int num_clusters)
2598{
2599	return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2600				    start_blk, num_clusters,
2601				    _ocfs2_set_bit);
2602}
2603
2604/*
2605 * Give never-used clusters back to the global bitmap.  We don't need
2606 * to protect these bits in the undo buffer.
2607 */
2608int ocfs2_release_clusters(handle_t *handle,
2609			   struct inode *bitmap_inode,
2610			   struct buffer_head *bitmap_bh,
2611			   u64 start_blk,
2612			   unsigned int num_clusters)
2613{
2614	return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2615				    start_blk, num_clusters,
2616				    _ocfs2_clear_bit);
2617}
2618
2619static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg)
2620{
2621	printk("Block Group:\n");
2622	printk("bg_signature:       %s\n", bg->bg_signature);
2623	printk("bg_size:            %u\n", bg->bg_size);
2624	printk("bg_bits:            %u\n", bg->bg_bits);
2625	printk("bg_free_bits_count: %u\n", bg->bg_free_bits_count);
2626	printk("bg_chain:           %u\n", bg->bg_chain);
2627	printk("bg_generation:      %u\n", le32_to_cpu(bg->bg_generation));
2628	printk("bg_next_group:      %llu\n",
2629	       (unsigned long long)bg->bg_next_group);
2630	printk("bg_parent_dinode:   %llu\n",
2631	       (unsigned long long)bg->bg_parent_dinode);
2632	printk("bg_blkno:           %llu\n",
2633	       (unsigned long long)bg->bg_blkno);
2634}
2635
2636static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe)
2637{
2638	int i;
2639
2640	printk("Suballoc Inode %llu:\n", (unsigned long long)fe->i_blkno);
2641	printk("i_signature:                  %s\n", fe->i_signature);
2642	printk("i_size:                       %llu\n",
2643	       (unsigned long long)fe->i_size);
2644	printk("i_clusters:                   %u\n", fe->i_clusters);
2645	printk("i_generation:                 %u\n",
2646	       le32_to_cpu(fe->i_generation));
2647	printk("id1.bitmap1.i_used:           %u\n",
2648	       le32_to_cpu(fe->id1.bitmap1.i_used));
2649	printk("id1.bitmap1.i_total:          %u\n",
2650	       le32_to_cpu(fe->id1.bitmap1.i_total));
2651	printk("id2.i_chain.cl_cpg:           %u\n", fe->id2.i_chain.cl_cpg);
2652	printk("id2.i_chain.cl_bpc:           %u\n", fe->id2.i_chain.cl_bpc);
2653	printk("id2.i_chain.cl_count:         %u\n", fe->id2.i_chain.cl_count);
2654	printk("id2.i_chain.cl_next_free_rec: %u\n",
2655	       fe->id2.i_chain.cl_next_free_rec);
2656	for(i = 0; i < fe->id2.i_chain.cl_next_free_rec; i++) {
2657		printk("fe->id2.i_chain.cl_recs[%d].c_free:  %u\n", i,
2658		       fe->id2.i_chain.cl_recs[i].c_free);
2659		printk("fe->id2.i_chain.cl_recs[%d].c_total: %u\n", i,
2660		       fe->id2.i_chain.cl_recs[i].c_total);
2661		printk("fe->id2.i_chain.cl_recs[%d].c_blkno: %llu\n", i,
2662		       (unsigned long long)fe->id2.i_chain.cl_recs[i].c_blkno);
2663	}
2664}
2665
2666/*
2667 * For a given allocation, determine which allocators will need to be
2668 * accessed, and lock them, reserving the appropriate number of bits.
2669 *
2670 * Sparse file systems call this from ocfs2_write_begin_nolock()
2671 * and ocfs2_allocate_unwritten_extents().
2672 *
2673 * File systems which don't support holes call this from
2674 * ocfs2_extend_allocation().
2675 */
2676int ocfs2_lock_allocators(struct inode *inode,
2677			  struct ocfs2_extent_tree *et,
2678			  u32 clusters_to_add, u32 extents_to_split,
2679			  struct ocfs2_alloc_context **data_ac,
2680			  struct ocfs2_alloc_context **meta_ac)
2681{
2682	int ret = 0, num_free_extents;
2683	unsigned int max_recs_needed = clusters_to_add + 2 * extents_to_split;
2684	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2685
2686	*meta_ac = NULL;
2687	if (data_ac)
2688		*data_ac = NULL;
2689
2690	BUG_ON(clusters_to_add != 0 && data_ac == NULL);
2691
2692	num_free_extents = ocfs2_num_free_extents(osb, et);
2693	if (num_free_extents < 0) {
2694		ret = num_free_extents;
2695		mlog_errno(ret);
2696		goto out;
2697	}
2698
2699	/*
2700	 * Sparse allocation file systems need to be more conservative
2701	 * with reserving room for expansion - the actual allocation
2702	 * happens while we've got a journal handle open so re-taking
2703	 * a cluster lock (because we ran out of room for another
2704	 * extent) will violate ordering rules.
2705	 *
2706	 * Most of the time we'll only be seeing this 1 cluster at a time
2707	 * anyway.
2708	 *
2709	 * Always lock for any unwritten extents - we might want to
2710	 * add blocks during a split.
2711	 */
2712	if (!num_free_extents ||
2713	    (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed)) {
2714		ret = ocfs2_reserve_new_metadata(osb, et->et_root_el, meta_ac);
2715		if (ret < 0) {
2716			if (ret != -ENOSPC)
2717				mlog_errno(ret);
2718			goto out;
2719		}
2720	}
2721
2722	if (clusters_to_add == 0)
2723		goto out;
2724
2725	ret = ocfs2_reserve_clusters(osb, clusters_to_add, data_ac);
2726	if (ret < 0) {
2727		if (ret != -ENOSPC)
2728			mlog_errno(ret);
2729		goto out;
2730	}
2731
2732out:
2733	if (ret) {
2734		if (*meta_ac) {
2735			ocfs2_free_alloc_context(*meta_ac);
2736			*meta_ac = NULL;
2737		}
2738
2739		/*
2740		 * We cannot have an error and a non null *data_ac.
2741		 */
2742	}
2743
2744	return ret;
2745}
2746
2747/*
2748 * Read the inode specified by blkno to get suballoc_slot and
2749 * suballoc_bit.
2750 */
2751static int ocfs2_get_suballoc_slot_bit(struct ocfs2_super *osb, u64 blkno,
2752				       u16 *suballoc_slot, u64 *group_blkno,
2753				       u16 *suballoc_bit)
2754{
2755	int status;
2756	struct buffer_head *inode_bh = NULL;
2757	struct ocfs2_dinode *inode_fe;
2758
2759	trace_ocfs2_get_suballoc_slot_bit((unsigned long long)blkno);
2760
2761	/* dirty read disk */
2762	status = ocfs2_read_blocks_sync(osb, blkno, 1, &inode_bh);
2763	if (status < 0) {
2764		mlog(ML_ERROR, "read block %llu failed %d\n",
2765		     (unsigned long long)blkno, status);
2766		goto bail;
2767	}
2768
2769	inode_fe = (struct ocfs2_dinode *) inode_bh->b_data;
2770	if (!OCFS2_IS_VALID_DINODE(inode_fe)) {
2771		mlog(ML_ERROR, "invalid inode %llu requested\n",
2772		     (unsigned long long)blkno);
2773		status = -EINVAL;
2774		goto bail;
2775	}
2776
2777	if (le16_to_cpu(inode_fe->i_suballoc_slot) != (u16)OCFS2_INVALID_SLOT &&
2778	    (u32)le16_to_cpu(inode_fe->i_suballoc_slot) > osb->max_slots - 1) {
2779		mlog(ML_ERROR, "inode %llu has invalid suballoc slot %u\n",
2780		     (unsigned long long)blkno,
2781		     (u32)le16_to_cpu(inode_fe->i_suballoc_slot));
2782		status = -EINVAL;
2783		goto bail;
2784	}
2785
2786	if (suballoc_slot)
2787		*suballoc_slot = le16_to_cpu(inode_fe->i_suballoc_slot);
2788	if (suballoc_bit)
2789		*suballoc_bit = le16_to_cpu(inode_fe->i_suballoc_bit);
2790	if (group_blkno)
2791		*group_blkno = le64_to_cpu(inode_fe->i_suballoc_loc);
2792
2793bail:
2794	brelse(inode_bh);
2795
2796	if (status)
2797		mlog_errno(status);
2798	return status;
2799}
2800
2801/*
2802 * test whether bit is SET in allocator bitmap or not.  on success, 0
2803 * is returned and *res is 1 for SET; 0 otherwise.  when fails, errno
2804 * is returned and *res is meaningless.  Call this after you have
2805 * cluster locked against suballoc, or you may get a result based on
2806 * non-up2date contents
2807 */
2808static int ocfs2_test_suballoc_bit(struct ocfs2_super *osb,
2809				   struct inode *suballoc,
2810				   struct buffer_head *alloc_bh,
2811				   u64 group_blkno, u64 blkno,
2812				   u16 bit, int *res)
2813{
2814	struct ocfs2_dinode *alloc_di;
2815	struct ocfs2_group_desc *group;
2816	struct buffer_head *group_bh = NULL;
2817	u64 bg_blkno;
2818	int status;
2819
2820	trace_ocfs2_test_suballoc_bit((unsigned long long)blkno,
2821				      (unsigned int)bit);
2822
2823	alloc_di = (struct ocfs2_dinode *)alloc_bh->b_data;
2824	if ((bit + 1) > ocfs2_bits_per_group(&alloc_di->id2.i_chain)) {
2825		mlog(ML_ERROR, "suballoc bit %u out of range of %u\n",
2826		     (unsigned int)bit,
2827		     ocfs2_bits_per_group(&alloc_di->id2.i_chain));
2828		status = -EINVAL;
2829		goto bail;
2830	}
2831
2832	bg_blkno = group_blkno ? group_blkno :
2833		   ocfs2_which_suballoc_group(blkno, bit);
2834	status = ocfs2_read_group_descriptor(suballoc, alloc_di, bg_blkno,
2835					     &group_bh);
2836	if (status < 0) {
2837		mlog(ML_ERROR, "read group %llu failed %d\n",
2838		     (unsigned long long)bg_blkno, status);
2839		goto bail;
2840	}
2841
2842	group = (struct ocfs2_group_desc *) group_bh->b_data;
2843	*res = ocfs2_test_bit(bit, (unsigned long *)group->bg_bitmap);
2844
2845bail:
2846	brelse(group_bh);
2847
2848	if (status)
2849		mlog_errno(status);
2850	return status;
2851}
2852
2853/*
2854 * Test if the bit representing this inode (blkno) is set in the
2855 * suballocator.
2856 *
2857 * On success, 0 is returned and *res is 1 for SET; 0 otherwise.
2858 *
2859 * In the event of failure, a negative value is returned and *res is
2860 * meaningless.
2861 *
2862 * Callers must make sure to hold nfs_sync_lock to prevent
2863 * ocfs2_delete_inode() on another node from accessing the same
2864 * suballocator concurrently.
2865 */
2866int ocfs2_test_inode_bit(struct ocfs2_super *osb, u64 blkno, int *res)
2867{
2868	int status;
2869	u64 group_blkno = 0;
2870	u16 suballoc_bit = 0, suballoc_slot = 0;
2871	struct inode *inode_alloc_inode;
2872	struct buffer_head *alloc_bh = NULL;
2873
2874	trace_ocfs2_test_inode_bit((unsigned long long)blkno);
2875
2876	status = ocfs2_get_suballoc_slot_bit(osb, blkno, &suballoc_slot,
2877					     &group_blkno, &suballoc_bit);
2878	if (status < 0) {
2879		mlog(ML_ERROR, "get alloc slot and bit failed %d\n", status);
2880		goto bail;
2881	}
2882
2883	inode_alloc_inode =
2884		ocfs2_get_system_file_inode(osb, INODE_ALLOC_SYSTEM_INODE,
2885					    suballoc_slot);
2886	if (!inode_alloc_inode) {
2887		/* the error code could be inaccurate, but we are not able to
2888		 * get the correct one. */
2889		status = -EINVAL;
2890		mlog(ML_ERROR, "unable to get alloc inode in slot %u\n",
2891		     (u32)suballoc_slot);
2892		goto bail;
2893	}
2894
2895	mutex_lock(&inode_alloc_inode->i_mutex);
2896	status = ocfs2_inode_lock(inode_alloc_inode, &alloc_bh, 0);
2897	if (status < 0) {
2898		mutex_unlock(&inode_alloc_inode->i_mutex);
2899		iput(inode_alloc_inode);
2900		mlog(ML_ERROR, "lock on alloc inode on slot %u failed %d\n",
2901		     (u32)suballoc_slot, status);
2902		goto bail;
2903	}
2904
2905	status = ocfs2_test_suballoc_bit(osb, inode_alloc_inode, alloc_bh,
2906					 group_blkno, blkno, suballoc_bit, res);
2907	if (status < 0)
2908		mlog(ML_ERROR, "test suballoc bit failed %d\n", status);
2909
2910	ocfs2_inode_unlock(inode_alloc_inode, 0);
2911	mutex_unlock(&inode_alloc_inode->i_mutex);
2912
2913	iput(inode_alloc_inode);
2914	brelse(alloc_bh);
2915bail:
2916	if (status)
2917		mlog_errno(status);
2918	return status;
2919}
2920