1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * suballoc.c
4 *
5 * metadata alloc and free
6 * Inspired by ext3 block groups.
7 *
8 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
9 */
10
11#include <linux/fs.h>
12#include <linux/types.h>
13#include <linux/slab.h>
14#include <linux/highmem.h>
15
16#include <cluster/masklog.h>
17
18#include "ocfs2.h"
19
20#include "alloc.h"
21#include "blockcheck.h"
22#include "dlmglue.h"
23#include "inode.h"
24#include "journal.h"
25#include "localalloc.h"
26#include "suballoc.h"
27#include "super.h"
28#include "sysfile.h"
29#include "uptodate.h"
30#include "ocfs2_trace.h"
31
32#include "buffer_head_io.h"
33
34#define NOT_ALLOC_NEW_GROUP		0
35#define ALLOC_NEW_GROUP			0x1
36#define ALLOC_GROUPS_FROM_GLOBAL	0x2
37
38#define OCFS2_MAX_TO_STEAL		1024
39
40struct ocfs2_suballoc_result {
41	u64		sr_bg_blkno;	/* The bg we allocated from.  Set
42					   to 0 when a block group is
43					   contiguous. */
44	u64		sr_bg_stable_blkno; /*
45					     * Doesn't change, always
46					     * set to target block
47					     * group descriptor
48					     * block.
49					     */
50	u64		sr_blkno;	/* The first allocated block */
51	unsigned int	sr_bit_offset;	/* The bit in the bg */
52	unsigned int	sr_bits;	/* How many bits we claimed */
53};
54
55static u64 ocfs2_group_from_res(struct ocfs2_suballoc_result *res)
56{
57	if (res->sr_blkno == 0)
58		return 0;
59
60	if (res->sr_bg_blkno)
61		return res->sr_bg_blkno;
62
63	return ocfs2_which_suballoc_group(res->sr_blkno, res->sr_bit_offset);
64}
65
66static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl);
67static int ocfs2_block_group_fill(handle_t *handle,
68				  struct inode *alloc_inode,
69				  struct buffer_head *bg_bh,
70				  u64 group_blkno,
71				  unsigned int group_clusters,
72				  u16 my_chain,
73				  struct ocfs2_chain_list *cl);
74static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
75				   struct inode *alloc_inode,
76				   struct buffer_head *bh,
77				   u64 max_block,
78				   u64 *last_alloc_group,
79				   int flags);
80
81static int ocfs2_cluster_group_search(struct inode *inode,
82				      struct buffer_head *group_bh,
83				      u32 bits_wanted, u32 min_bits,
84				      u64 max_block,
85				      struct ocfs2_suballoc_result *res);
86static int ocfs2_block_group_search(struct inode *inode,
87				    struct buffer_head *group_bh,
88				    u32 bits_wanted, u32 min_bits,
89				    u64 max_block,
90				    struct ocfs2_suballoc_result *res);
91static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
92				     handle_t *handle,
93				     u32 bits_wanted,
94				     u32 min_bits,
95				     struct ocfs2_suballoc_result *res);
96static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
97					 int nr);
98static int ocfs2_relink_block_group(handle_t *handle,
99				    struct inode *alloc_inode,
100				    struct buffer_head *fe_bh,
101				    struct buffer_head *bg_bh,
102				    struct buffer_head *prev_bg_bh,
103				    u16 chain);
104static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
105						     u32 wanted);
106static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
107						   u64 bg_blkno,
108						   u16 bg_bit_off);
109static inline void ocfs2_block_to_cluster_group(struct inode *inode,
110						u64 data_blkno,
111						u64 *bg_blkno,
112						u16 *bg_bit_off);
113static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
114					     u32 bits_wanted, u64 max_block,
115					     int flags,
116					     struct ocfs2_alloc_context **ac);
117
118void ocfs2_free_ac_resource(struct ocfs2_alloc_context *ac)
119{
120	struct inode *inode = ac->ac_inode;
121
122	if (inode) {
123		if (ac->ac_which != OCFS2_AC_USE_LOCAL)
124			ocfs2_inode_unlock(inode, 1);
125
126		inode_unlock(inode);
127
128		iput(inode);
129		ac->ac_inode = NULL;
130	}
131	brelse(ac->ac_bh);
132	ac->ac_bh = NULL;
133	ac->ac_resv = NULL;
134	kfree(ac->ac_find_loc_priv);
135	ac->ac_find_loc_priv = NULL;
136}
137
138void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
139{
140	ocfs2_free_ac_resource(ac);
141	kfree(ac);
142}
143
144static u32 ocfs2_bits_per_group(struct ocfs2_chain_list *cl)
145{
146	return (u32)le16_to_cpu(cl->cl_cpg) * (u32)le16_to_cpu(cl->cl_bpc);
147}
148
149#define do_error(fmt, ...)						\
150do {									\
151	if (resize)							\
152		mlog(ML_ERROR, fmt, ##__VA_ARGS__);			\
153	else								\
154		return ocfs2_error(sb, fmt, ##__VA_ARGS__);		\
155} while (0)
156
157static int ocfs2_validate_gd_self(struct super_block *sb,
158				  struct buffer_head *bh,
159				  int resize)
160{
161	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
162
163	if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
164		do_error("Group descriptor #%llu has bad signature %.*s\n",
165			 (unsigned long long)bh->b_blocknr, 7,
166			 gd->bg_signature);
167	}
168
169	if (le64_to_cpu(gd->bg_blkno) != bh->b_blocknr) {
170		do_error("Group descriptor #%llu has an invalid bg_blkno of %llu\n",
171			 (unsigned long long)bh->b_blocknr,
172			 (unsigned long long)le64_to_cpu(gd->bg_blkno));
173	}
174
175	if (le32_to_cpu(gd->bg_generation) != OCFS2_SB(sb)->fs_generation) {
176		do_error("Group descriptor #%llu has an invalid fs_generation of #%u\n",
177			 (unsigned long long)bh->b_blocknr,
178			 le32_to_cpu(gd->bg_generation));
179	}
180
181	if (le16_to_cpu(gd->bg_free_bits_count) > le16_to_cpu(gd->bg_bits)) {
182		do_error("Group descriptor #%llu has bit count %u but claims that %u are free\n",
183			 (unsigned long long)bh->b_blocknr,
184			 le16_to_cpu(gd->bg_bits),
185			 le16_to_cpu(gd->bg_free_bits_count));
186	}
187
188	if (le16_to_cpu(gd->bg_bits) > (8 * le16_to_cpu(gd->bg_size))) {
189		do_error("Group descriptor #%llu has bit count %u but max bitmap bits of %u\n",
190			 (unsigned long long)bh->b_blocknr,
191			 le16_to_cpu(gd->bg_bits),
192			 8 * le16_to_cpu(gd->bg_size));
193	}
194
195	return 0;
196}
197
198static int ocfs2_validate_gd_parent(struct super_block *sb,
199				    struct ocfs2_dinode *di,
200				    struct buffer_head *bh,
201				    int resize)
202{
203	unsigned int max_bits;
204	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
205
206	if (di->i_blkno != gd->bg_parent_dinode) {
207		do_error("Group descriptor #%llu has bad parent pointer (%llu, expected %llu)\n",
208			 (unsigned long long)bh->b_blocknr,
209			 (unsigned long long)le64_to_cpu(gd->bg_parent_dinode),
210			 (unsigned long long)le64_to_cpu(di->i_blkno));
211	}
212
213	max_bits = le16_to_cpu(di->id2.i_chain.cl_cpg) * le16_to_cpu(di->id2.i_chain.cl_bpc);
214	if (le16_to_cpu(gd->bg_bits) > max_bits) {
215		do_error("Group descriptor #%llu has bit count of %u\n",
216			 (unsigned long long)bh->b_blocknr,
217			 le16_to_cpu(gd->bg_bits));
218	}
219
220	/* In resize, we may meet the case bg_chain == cl_next_free_rec. */
221	if ((le16_to_cpu(gd->bg_chain) >
222	     le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) ||
223	    ((le16_to_cpu(gd->bg_chain) ==
224	     le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) && !resize)) {
225		do_error("Group descriptor #%llu has bad chain %u\n",
226			 (unsigned long long)bh->b_blocknr,
227			 le16_to_cpu(gd->bg_chain));
228	}
229
230	return 0;
231}
232
233#undef do_error
234
235/*
236 * This version only prints errors.  It does not fail the filesystem, and
237 * exists only for resize.
238 */
239int ocfs2_check_group_descriptor(struct super_block *sb,
240				 struct ocfs2_dinode *di,
241				 struct buffer_head *bh)
242{
243	int rc;
244	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
245
246	BUG_ON(!buffer_uptodate(bh));
247
248	/*
249	 * If the ecc fails, we return the error but otherwise
250	 * leave the filesystem running.  We know any error is
251	 * local to this block.
252	 */
253	rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
254	if (rc) {
255		mlog(ML_ERROR,
256		     "Checksum failed for group descriptor %llu\n",
257		     (unsigned long long)bh->b_blocknr);
258	} else
259		rc = ocfs2_validate_gd_self(sb, bh, 1);
260	if (!rc)
261		rc = ocfs2_validate_gd_parent(sb, di, bh, 1);
262
263	return rc;
264}
265
266static int ocfs2_validate_group_descriptor(struct super_block *sb,
267					   struct buffer_head *bh)
268{
269	int rc;
270	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
271
272	trace_ocfs2_validate_group_descriptor(
273					(unsigned long long)bh->b_blocknr);
274
275	BUG_ON(!buffer_uptodate(bh));
276
277	/*
278	 * If the ecc fails, we return the error but otherwise
279	 * leave the filesystem running.  We know any error is
280	 * local to this block.
281	 */
282	rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
283	if (rc)
284		return rc;
285
286	/*
287	 * Errors after here are fatal.
288	 */
289
290	return ocfs2_validate_gd_self(sb, bh, 0);
291}
292
293int ocfs2_read_group_descriptor(struct inode *inode, struct ocfs2_dinode *di,
294				u64 gd_blkno, struct buffer_head **bh)
295{
296	int rc;
297	struct buffer_head *tmp = *bh;
298
299	rc = ocfs2_read_block(INODE_CACHE(inode), gd_blkno, &tmp,
300			      ocfs2_validate_group_descriptor);
301	if (rc)
302		goto out;
303
304	rc = ocfs2_validate_gd_parent(inode->i_sb, di, tmp, 0);
305	if (rc) {
306		brelse(tmp);
307		goto out;
308	}
309
310	/* If ocfs2_read_block() got us a new bh, pass it up. */
311	if (!*bh)
312		*bh = tmp;
313
314out:
315	return rc;
316}
317
318static void ocfs2_bg_discontig_add_extent(struct ocfs2_super *osb,
319					  struct ocfs2_group_desc *bg,
320					  struct ocfs2_chain_list *cl,
321					  u64 p_blkno, unsigned int clusters)
322{
323	struct ocfs2_extent_list *el = &bg->bg_list;
324	struct ocfs2_extent_rec *rec;
325
326	BUG_ON(!ocfs2_supports_discontig_bg(osb));
327	if (!el->l_next_free_rec)
328		el->l_count = cpu_to_le16(ocfs2_extent_recs_per_gd(osb->sb));
329	rec = &el->l_recs[le16_to_cpu(el->l_next_free_rec)];
330	rec->e_blkno = cpu_to_le64(p_blkno);
331	rec->e_cpos = cpu_to_le32(le16_to_cpu(bg->bg_bits) /
332				  le16_to_cpu(cl->cl_bpc));
333	rec->e_leaf_clusters = cpu_to_le16(clusters);
334	le16_add_cpu(&bg->bg_bits, clusters * le16_to_cpu(cl->cl_bpc));
335	le16_add_cpu(&bg->bg_free_bits_count,
336		     clusters * le16_to_cpu(cl->cl_bpc));
337	le16_add_cpu(&el->l_next_free_rec, 1);
338}
339
340static int ocfs2_block_group_fill(handle_t *handle,
341				  struct inode *alloc_inode,
342				  struct buffer_head *bg_bh,
343				  u64 group_blkno,
344				  unsigned int group_clusters,
345				  u16 my_chain,
346				  struct ocfs2_chain_list *cl)
347{
348	int status = 0;
349	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
350	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
351	struct super_block * sb = alloc_inode->i_sb;
352
353	if (((unsigned long long) bg_bh->b_blocknr) != group_blkno) {
354		status = ocfs2_error(alloc_inode->i_sb,
355				     "group block (%llu) != b_blocknr (%llu)\n",
356				     (unsigned long long)group_blkno,
357				     (unsigned long long) bg_bh->b_blocknr);
358		goto bail;
359	}
360
361	status = ocfs2_journal_access_gd(handle,
362					 INODE_CACHE(alloc_inode),
363					 bg_bh,
364					 OCFS2_JOURNAL_ACCESS_CREATE);
365	if (status < 0) {
366		mlog_errno(status);
367		goto bail;
368	}
369
370	memset(bg, 0, sb->s_blocksize);
371	strcpy(bg->bg_signature, OCFS2_GROUP_DESC_SIGNATURE);
372	bg->bg_generation = cpu_to_le32(osb->fs_generation);
373	bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb, 1,
374						osb->s_feature_incompat));
375	bg->bg_chain = cpu_to_le16(my_chain);
376	bg->bg_next_group = cl->cl_recs[my_chain].c_blkno;
377	bg->bg_parent_dinode = cpu_to_le64(OCFS2_I(alloc_inode)->ip_blkno);
378	bg->bg_blkno = cpu_to_le64(group_blkno);
379	if (group_clusters == le16_to_cpu(cl->cl_cpg))
380		bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
381	else
382		ocfs2_bg_discontig_add_extent(osb, bg, cl, group_blkno,
383					      group_clusters);
384
385	/* set the 1st bit in the bitmap to account for the descriptor block */
386	ocfs2_set_bit(0, (unsigned long *)bg->bg_bitmap);
387	bg->bg_free_bits_count = cpu_to_le16(le16_to_cpu(bg->bg_bits) - 1);
388
389	ocfs2_journal_dirty(handle, bg_bh);
390
391	/* There is no need to zero out or otherwise initialize the
392	 * other blocks in a group - All valid FS metadata in a block
393	 * group stores the superblock fs_generation value at
394	 * allocation time. */
395
396bail:
397	if (status)
398		mlog_errno(status);
399	return status;
400}
401
402static inline u16 ocfs2_find_smallest_chain(struct ocfs2_chain_list *cl)
403{
404	u16 curr, best;
405
406	best = curr = 0;
407	while (curr < le16_to_cpu(cl->cl_count)) {
408		if (le32_to_cpu(cl->cl_recs[best].c_total) >
409		    le32_to_cpu(cl->cl_recs[curr].c_total))
410			best = curr;
411		curr++;
412	}
413	return best;
414}
415
416static struct buffer_head *
417ocfs2_block_group_alloc_contig(struct ocfs2_super *osb, handle_t *handle,
418			       struct inode *alloc_inode,
419			       struct ocfs2_alloc_context *ac,
420			       struct ocfs2_chain_list *cl)
421{
422	int status;
423	u32 bit_off, num_bits;
424	u64 bg_blkno;
425	struct buffer_head *bg_bh;
426	unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
427
428	status = ocfs2_claim_clusters(handle, ac,
429				      le16_to_cpu(cl->cl_cpg), &bit_off,
430				      &num_bits);
431	if (status < 0) {
432		if (status != -ENOSPC)
433			mlog_errno(status);
434		goto bail;
435	}
436
437	/* setup the group */
438	bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
439	trace_ocfs2_block_group_alloc_contig(
440	     (unsigned long long)bg_blkno, alloc_rec);
441
442	bg_bh = sb_getblk(osb->sb, bg_blkno);
443	if (!bg_bh) {
444		status = -ENOMEM;
445		mlog_errno(status);
446		goto bail;
447	}
448	ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
449
450	status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
451					bg_blkno, num_bits, alloc_rec, cl);
452	if (status < 0) {
453		brelse(bg_bh);
454		mlog_errno(status);
455	}
456
457bail:
458	return status ? ERR_PTR(status) : bg_bh;
459}
460
461static int ocfs2_block_group_claim_bits(struct ocfs2_super *osb,
462					handle_t *handle,
463					struct ocfs2_alloc_context *ac,
464					unsigned int min_bits,
465					u32 *bit_off, u32 *num_bits)
466{
467	int status = 0;
468
469	while (min_bits) {
470		status = ocfs2_claim_clusters(handle, ac, min_bits,
471					      bit_off, num_bits);
472		if (status != -ENOSPC)
473			break;
474
475		min_bits >>= 1;
476	}
477
478	return status;
479}
480
481static int ocfs2_block_group_grow_discontig(handle_t *handle,
482					    struct inode *alloc_inode,
483					    struct buffer_head *bg_bh,
484					    struct ocfs2_alloc_context *ac,
485					    struct ocfs2_chain_list *cl,
486					    unsigned int min_bits)
487{
488	int status;
489	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
490	struct ocfs2_group_desc *bg =
491		(struct ocfs2_group_desc *)bg_bh->b_data;
492	unsigned int needed = le16_to_cpu(cl->cl_cpg) -
493			 le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
494	u32 p_cpos, clusters;
495	u64 p_blkno;
496	struct ocfs2_extent_list *el = &bg->bg_list;
497
498	status = ocfs2_journal_access_gd(handle,
499					 INODE_CACHE(alloc_inode),
500					 bg_bh,
501					 OCFS2_JOURNAL_ACCESS_CREATE);
502	if (status < 0) {
503		mlog_errno(status);
504		goto bail;
505	}
506
507	while ((needed > 0) && (le16_to_cpu(el->l_next_free_rec) <
508				le16_to_cpu(el->l_count))) {
509		if (min_bits > needed)
510			min_bits = needed;
511		status = ocfs2_block_group_claim_bits(osb, handle, ac,
512						      min_bits, &p_cpos,
513						      &clusters);
514		if (status < 0) {
515			if (status != -ENOSPC)
516				mlog_errno(status);
517			goto bail;
518		}
519		p_blkno = ocfs2_clusters_to_blocks(osb->sb, p_cpos);
520		ocfs2_bg_discontig_add_extent(osb, bg, cl, p_blkno,
521					      clusters);
522
523		min_bits = clusters;
524		needed = le16_to_cpu(cl->cl_cpg) -
525			 le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
526	}
527
528	if (needed > 0) {
529		/*
530		 * We have used up all the extent rec but can't fill up
531		 * the cpg. So bail out.
532		 */
533		status = -ENOSPC;
534		goto bail;
535	}
536
537	ocfs2_journal_dirty(handle, bg_bh);
538
539bail:
540	return status;
541}
542
543static void ocfs2_bg_alloc_cleanup(handle_t *handle,
544				   struct ocfs2_alloc_context *cluster_ac,
545				   struct inode *alloc_inode,
546				   struct buffer_head *bg_bh)
547{
548	int i, ret;
549	struct ocfs2_group_desc *bg;
550	struct ocfs2_extent_list *el;
551	struct ocfs2_extent_rec *rec;
552
553	if (!bg_bh)
554		return;
555
556	bg = (struct ocfs2_group_desc *)bg_bh->b_data;
557	el = &bg->bg_list;
558	for (i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
559		rec = &el->l_recs[i];
560		ret = ocfs2_free_clusters(handle, cluster_ac->ac_inode,
561					  cluster_ac->ac_bh,
562					  le64_to_cpu(rec->e_blkno),
563					  le16_to_cpu(rec->e_leaf_clusters));
564		if (ret)
565			mlog_errno(ret);
566		/* Try all the clusters to free */
567	}
568
569	ocfs2_remove_from_cache(INODE_CACHE(alloc_inode), bg_bh);
570	brelse(bg_bh);
571}
572
573static struct buffer_head *
574ocfs2_block_group_alloc_discontig(handle_t *handle,
575				  struct inode *alloc_inode,
576				  struct ocfs2_alloc_context *ac,
577				  struct ocfs2_chain_list *cl)
578{
579	int status;
580	u32 bit_off, num_bits;
581	u64 bg_blkno;
582	unsigned int min_bits = le16_to_cpu(cl->cl_cpg) >> 1;
583	struct buffer_head *bg_bh = NULL;
584	unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
585	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
586
587	if (!ocfs2_supports_discontig_bg(osb)) {
588		status = -ENOSPC;
589		goto bail;
590	}
591
592	status = ocfs2_extend_trans(handle,
593				    ocfs2_calc_bg_discontig_credits(osb->sb));
594	if (status) {
595		mlog_errno(status);
596		goto bail;
597	}
598
599	/*
600	 * We're going to be grabbing from multiple cluster groups.
601	 * We don't have enough credits to relink them all, and the
602	 * cluster groups will be staying in cache for the duration of
603	 * this operation.
604	 */
605	ac->ac_disable_chain_relink = 1;
606
607	/* Claim the first region */
608	status = ocfs2_block_group_claim_bits(osb, handle, ac, min_bits,
609					      &bit_off, &num_bits);
610	if (status < 0) {
611		if (status != -ENOSPC)
612			mlog_errno(status);
613		goto bail;
614	}
615	min_bits = num_bits;
616
617	/* setup the group */
618	bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
619	trace_ocfs2_block_group_alloc_discontig(
620				(unsigned long long)bg_blkno, alloc_rec);
621
622	bg_bh = sb_getblk(osb->sb, bg_blkno);
623	if (!bg_bh) {
624		status = -ENOMEM;
625		mlog_errno(status);
626		goto bail;
627	}
628	ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
629
630	status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
631					bg_blkno, num_bits, alloc_rec, cl);
632	if (status < 0) {
633		mlog_errno(status);
634		goto bail;
635	}
636
637	status = ocfs2_block_group_grow_discontig(handle, alloc_inode,
638						  bg_bh, ac, cl, min_bits);
639	if (status)
640		mlog_errno(status);
641
642bail:
643	if (status)
644		ocfs2_bg_alloc_cleanup(handle, ac, alloc_inode, bg_bh);
645	return status ? ERR_PTR(status) : bg_bh;
646}
647
648/*
649 * We expect the block group allocator to already be locked.
650 */
651static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
652				   struct inode *alloc_inode,
653				   struct buffer_head *bh,
654				   u64 max_block,
655				   u64 *last_alloc_group,
656				   int flags)
657{
658	int status, credits;
659	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) bh->b_data;
660	struct ocfs2_chain_list *cl;
661	struct ocfs2_alloc_context *ac = NULL;
662	handle_t *handle = NULL;
663	u16 alloc_rec;
664	struct buffer_head *bg_bh = NULL;
665	struct ocfs2_group_desc *bg;
666
667	BUG_ON(ocfs2_is_cluster_bitmap(alloc_inode));
668
669	cl = &fe->id2.i_chain;
670	status = ocfs2_reserve_clusters_with_limit(osb,
671						   le16_to_cpu(cl->cl_cpg),
672						   max_block, flags, &ac);
673	if (status < 0) {
674		if (status != -ENOSPC)
675			mlog_errno(status);
676		goto bail;
677	}
678
679	credits = ocfs2_calc_group_alloc_credits(osb->sb,
680						 le16_to_cpu(cl->cl_cpg));
681	handle = ocfs2_start_trans(osb, credits);
682	if (IS_ERR(handle)) {
683		status = PTR_ERR(handle);
684		handle = NULL;
685		mlog_errno(status);
686		goto bail;
687	}
688
689	if (last_alloc_group && *last_alloc_group != 0) {
690		trace_ocfs2_block_group_alloc(
691				(unsigned long long)*last_alloc_group);
692		ac->ac_last_group = *last_alloc_group;
693	}
694
695	bg_bh = ocfs2_block_group_alloc_contig(osb, handle, alloc_inode,
696					       ac, cl);
697	if (PTR_ERR(bg_bh) == -ENOSPC)
698		bg_bh = ocfs2_block_group_alloc_discontig(handle,
699							  alloc_inode,
700							  ac, cl);
701	if (IS_ERR(bg_bh)) {
702		status = PTR_ERR(bg_bh);
703		bg_bh = NULL;
704		if (status != -ENOSPC)
705			mlog_errno(status);
706		goto bail;
707	}
708	bg = (struct ocfs2_group_desc *) bg_bh->b_data;
709
710	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
711					 bh, OCFS2_JOURNAL_ACCESS_WRITE);
712	if (status < 0) {
713		mlog_errno(status);
714		goto bail;
715	}
716
717	alloc_rec = le16_to_cpu(bg->bg_chain);
718	le32_add_cpu(&cl->cl_recs[alloc_rec].c_free,
719		     le16_to_cpu(bg->bg_free_bits_count));
720	le32_add_cpu(&cl->cl_recs[alloc_rec].c_total,
721		     le16_to_cpu(bg->bg_bits));
722	cl->cl_recs[alloc_rec].c_blkno = bg->bg_blkno;
723	if (le16_to_cpu(cl->cl_next_free_rec) < le16_to_cpu(cl->cl_count))
724		le16_add_cpu(&cl->cl_next_free_rec, 1);
725
726	le32_add_cpu(&fe->id1.bitmap1.i_used, le16_to_cpu(bg->bg_bits) -
727					le16_to_cpu(bg->bg_free_bits_count));
728	le32_add_cpu(&fe->id1.bitmap1.i_total, le16_to_cpu(bg->bg_bits));
729	le32_add_cpu(&fe->i_clusters, le16_to_cpu(cl->cl_cpg));
730
731	ocfs2_journal_dirty(handle, bh);
732
733	spin_lock(&OCFS2_I(alloc_inode)->ip_lock);
734	OCFS2_I(alloc_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
735	fe->i_size = cpu_to_le64(ocfs2_clusters_to_bytes(alloc_inode->i_sb,
736					     le32_to_cpu(fe->i_clusters)));
737	spin_unlock(&OCFS2_I(alloc_inode)->ip_lock);
738	i_size_write(alloc_inode, le64_to_cpu(fe->i_size));
739	alloc_inode->i_blocks = ocfs2_inode_sector_count(alloc_inode);
740	ocfs2_update_inode_fsync_trans(handle, alloc_inode, 0);
741
742	status = 0;
743
744	/* save the new last alloc group so that the caller can cache it. */
745	if (last_alloc_group)
746		*last_alloc_group = ac->ac_last_group;
747
748bail:
749	if (handle)
750		ocfs2_commit_trans(osb, handle);
751
752	if (ac)
753		ocfs2_free_alloc_context(ac);
754
755	brelse(bg_bh);
756
757	if (status)
758		mlog_errno(status);
759	return status;
760}
761
762static int ocfs2_reserve_suballoc_bits(struct ocfs2_super *osb,
763				       struct ocfs2_alloc_context *ac,
764				       int type,
765				       u32 slot,
766				       u64 *last_alloc_group,
767				       int flags)
768{
769	int status;
770	u32 bits_wanted = ac->ac_bits_wanted;
771	struct inode *alloc_inode;
772	struct buffer_head *bh = NULL;
773	struct ocfs2_dinode *fe;
774	u32 free_bits;
775
776	alloc_inode = ocfs2_get_system_file_inode(osb, type, slot);
777	if (!alloc_inode) {
778		mlog_errno(-EINVAL);
779		return -EINVAL;
780	}
781
782	inode_lock(alloc_inode);
783
784	status = ocfs2_inode_lock(alloc_inode, &bh, 1);
785	if (status < 0) {
786		inode_unlock(alloc_inode);
787		iput(alloc_inode);
788
789		mlog_errno(status);
790		return status;
791	}
792
793	ac->ac_inode = alloc_inode;
794	ac->ac_alloc_slot = slot;
795
796	fe = (struct ocfs2_dinode *) bh->b_data;
797
798	/* The bh was validated by the inode read inside
799	 * ocfs2_inode_lock().  Any corruption is a code bug. */
800	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
801
802	if (!(fe->i_flags & cpu_to_le32(OCFS2_CHAIN_FL))) {
803		status = ocfs2_error(alloc_inode->i_sb,
804				     "Invalid chain allocator %llu\n",
805				     (unsigned long long)le64_to_cpu(fe->i_blkno));
806		goto bail;
807	}
808
809	free_bits = le32_to_cpu(fe->id1.bitmap1.i_total) -
810		le32_to_cpu(fe->id1.bitmap1.i_used);
811
812	if (bits_wanted > free_bits) {
813		/* cluster bitmap never grows */
814		if (ocfs2_is_cluster_bitmap(alloc_inode)) {
815			trace_ocfs2_reserve_suballoc_bits_nospc(bits_wanted,
816								free_bits);
817			status = -ENOSPC;
818			goto bail;
819		}
820
821		if (!(flags & ALLOC_NEW_GROUP)) {
822			trace_ocfs2_reserve_suballoc_bits_no_new_group(
823						slot, bits_wanted, free_bits);
824			status = -ENOSPC;
825			goto bail;
826		}
827
828		status = ocfs2_block_group_alloc(osb, alloc_inode, bh,
829						 ac->ac_max_block,
830						 last_alloc_group, flags);
831		if (status < 0) {
832			if (status != -ENOSPC)
833				mlog_errno(status);
834			goto bail;
835		}
836		atomic_inc(&osb->alloc_stats.bg_extends);
837
838		/* You should never ask for this much metadata */
839		BUG_ON(bits_wanted >
840		       (le32_to_cpu(fe->id1.bitmap1.i_total)
841			- le32_to_cpu(fe->id1.bitmap1.i_used)));
842	}
843
844	get_bh(bh);
845	ac->ac_bh = bh;
846bail:
847	brelse(bh);
848
849	if (status)
850		mlog_errno(status);
851	return status;
852}
853
854static void ocfs2_init_inode_steal_slot(struct ocfs2_super *osb)
855{
856	spin_lock(&osb->osb_lock);
857	osb->s_inode_steal_slot = OCFS2_INVALID_SLOT;
858	spin_unlock(&osb->osb_lock);
859	atomic_set(&osb->s_num_inodes_stolen, 0);
860}
861
862static void ocfs2_init_meta_steal_slot(struct ocfs2_super *osb)
863{
864	spin_lock(&osb->osb_lock);
865	osb->s_meta_steal_slot = OCFS2_INVALID_SLOT;
866	spin_unlock(&osb->osb_lock);
867	atomic_set(&osb->s_num_meta_stolen, 0);
868}
869
870void ocfs2_init_steal_slots(struct ocfs2_super *osb)
871{
872	ocfs2_init_inode_steal_slot(osb);
873	ocfs2_init_meta_steal_slot(osb);
874}
875
876static void __ocfs2_set_steal_slot(struct ocfs2_super *osb, int slot, int type)
877{
878	spin_lock(&osb->osb_lock);
879	if (type == INODE_ALLOC_SYSTEM_INODE)
880		osb->s_inode_steal_slot = (u16)slot;
881	else if (type == EXTENT_ALLOC_SYSTEM_INODE)
882		osb->s_meta_steal_slot = (u16)slot;
883	spin_unlock(&osb->osb_lock);
884}
885
886static int __ocfs2_get_steal_slot(struct ocfs2_super *osb, int type)
887{
888	int slot = OCFS2_INVALID_SLOT;
889
890	spin_lock(&osb->osb_lock);
891	if (type == INODE_ALLOC_SYSTEM_INODE)
892		slot = osb->s_inode_steal_slot;
893	else if (type == EXTENT_ALLOC_SYSTEM_INODE)
894		slot = osb->s_meta_steal_slot;
895	spin_unlock(&osb->osb_lock);
896
897	return slot;
898}
899
900static int ocfs2_get_inode_steal_slot(struct ocfs2_super *osb)
901{
902	return __ocfs2_get_steal_slot(osb, INODE_ALLOC_SYSTEM_INODE);
903}
904
905static int ocfs2_get_meta_steal_slot(struct ocfs2_super *osb)
906{
907	return __ocfs2_get_steal_slot(osb, EXTENT_ALLOC_SYSTEM_INODE);
908}
909
910static int ocfs2_steal_resource(struct ocfs2_super *osb,
911				struct ocfs2_alloc_context *ac,
912				int type)
913{
914	int i, status = -ENOSPC;
915	int slot = __ocfs2_get_steal_slot(osb, type);
916
917	/* Start to steal resource from the first slot after ours. */
918	if (slot == OCFS2_INVALID_SLOT)
919		slot = osb->slot_num + 1;
920
921	for (i = 0; i < osb->max_slots; i++, slot++) {
922		if (slot == osb->max_slots)
923			slot = 0;
924
925		if (slot == osb->slot_num)
926			continue;
927
928		status = ocfs2_reserve_suballoc_bits(osb, ac,
929						     type,
930						     (u32)slot, NULL,
931						     NOT_ALLOC_NEW_GROUP);
932		if (status >= 0) {
933			__ocfs2_set_steal_slot(osb, slot, type);
934			break;
935		}
936
937		ocfs2_free_ac_resource(ac);
938	}
939
940	return status;
941}
942
943static int ocfs2_steal_inode(struct ocfs2_super *osb,
944			     struct ocfs2_alloc_context *ac)
945{
946	return ocfs2_steal_resource(osb, ac, INODE_ALLOC_SYSTEM_INODE);
947}
948
949static int ocfs2_steal_meta(struct ocfs2_super *osb,
950			    struct ocfs2_alloc_context *ac)
951{
952	return ocfs2_steal_resource(osb, ac, EXTENT_ALLOC_SYSTEM_INODE);
953}
954
955int ocfs2_reserve_new_metadata_blocks(struct ocfs2_super *osb,
956				      int blocks,
957				      struct ocfs2_alloc_context **ac)
958{
959	int status;
960	int slot = ocfs2_get_meta_steal_slot(osb);
961
962	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
963	if (!(*ac)) {
964		status = -ENOMEM;
965		mlog_errno(status);
966		goto bail;
967	}
968
969	(*ac)->ac_bits_wanted = blocks;
970	(*ac)->ac_which = OCFS2_AC_USE_META;
971	(*ac)->ac_group_search = ocfs2_block_group_search;
972
973	if (slot != OCFS2_INVALID_SLOT &&
974		atomic_read(&osb->s_num_meta_stolen) < OCFS2_MAX_TO_STEAL)
975		goto extent_steal;
976
977	atomic_set(&osb->s_num_meta_stolen, 0);
978	status = ocfs2_reserve_suballoc_bits(osb, (*ac),
979					     EXTENT_ALLOC_SYSTEM_INODE,
980					     (u32)osb->slot_num, NULL,
981					     ALLOC_GROUPS_FROM_GLOBAL|ALLOC_NEW_GROUP);
982
983
984	if (status >= 0) {
985		status = 0;
986		if (slot != OCFS2_INVALID_SLOT)
987			ocfs2_init_meta_steal_slot(osb);
988		goto bail;
989	} else if (status < 0 && status != -ENOSPC) {
990		mlog_errno(status);
991		goto bail;
992	}
993
994	ocfs2_free_ac_resource(*ac);
995
996extent_steal:
997	status = ocfs2_steal_meta(osb, *ac);
998	atomic_inc(&osb->s_num_meta_stolen);
999	if (status < 0) {
1000		if (status != -ENOSPC)
1001			mlog_errno(status);
1002		goto bail;
1003	}
1004
1005	status = 0;
1006bail:
1007	if ((status < 0) && *ac) {
1008		ocfs2_free_alloc_context(*ac);
1009		*ac = NULL;
1010	}
1011
1012	if (status)
1013		mlog_errno(status);
1014	return status;
1015}
1016
1017int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
1018			       struct ocfs2_extent_list *root_el,
1019			       struct ocfs2_alloc_context **ac)
1020{
1021	return ocfs2_reserve_new_metadata_blocks(osb,
1022					ocfs2_extend_meta_needed(root_el),
1023					ac);
1024}
1025
1026int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
1027			    struct ocfs2_alloc_context **ac)
1028{
1029	int status;
1030	int slot = ocfs2_get_inode_steal_slot(osb);
1031	u64 alloc_group;
1032
1033	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1034	if (!(*ac)) {
1035		status = -ENOMEM;
1036		mlog_errno(status);
1037		goto bail;
1038	}
1039
1040	(*ac)->ac_bits_wanted = 1;
1041	(*ac)->ac_which = OCFS2_AC_USE_INODE;
1042
1043	(*ac)->ac_group_search = ocfs2_block_group_search;
1044
1045	/*
1046	 * stat(2) can't handle i_ino > 32bits, so we tell the
1047	 * lower levels not to allocate us a block group past that
1048	 * limit.  The 'inode64' mount option avoids this behavior.
1049	 */
1050	if (!(osb->s_mount_opt & OCFS2_MOUNT_INODE64))
1051		(*ac)->ac_max_block = (u32)~0U;
1052
1053	/*
1054	 * slot is set when we successfully steal inode from other nodes.
1055	 * It is reset in 3 places:
1056	 * 1. when we flush the truncate log
1057	 * 2. when we complete local alloc recovery.
1058	 * 3. when we successfully allocate from our own slot.
1059	 * After it is set, we will go on stealing inodes until we find the
1060	 * need to check our slots to see whether there is some space for us.
1061	 */
1062	if (slot != OCFS2_INVALID_SLOT &&
1063	    atomic_read(&osb->s_num_inodes_stolen) < OCFS2_MAX_TO_STEAL)
1064		goto inode_steal;
1065
1066	atomic_set(&osb->s_num_inodes_stolen, 0);
1067	alloc_group = osb->osb_inode_alloc_group;
1068	status = ocfs2_reserve_suballoc_bits(osb, *ac,
1069					     INODE_ALLOC_SYSTEM_INODE,
1070					     (u32)osb->slot_num,
1071					     &alloc_group,
1072					     ALLOC_NEW_GROUP |
1073					     ALLOC_GROUPS_FROM_GLOBAL);
1074	if (status >= 0) {
1075		status = 0;
1076
1077		spin_lock(&osb->osb_lock);
1078		osb->osb_inode_alloc_group = alloc_group;
1079		spin_unlock(&osb->osb_lock);
1080		trace_ocfs2_reserve_new_inode_new_group(
1081			(unsigned long long)alloc_group);
1082
1083		/*
1084		 * Some inodes must be freed by us, so try to allocate
1085		 * from our own next time.
1086		 */
1087		if (slot != OCFS2_INVALID_SLOT)
1088			ocfs2_init_inode_steal_slot(osb);
1089		goto bail;
1090	} else if (status < 0 && status != -ENOSPC) {
1091		mlog_errno(status);
1092		goto bail;
1093	}
1094
1095	ocfs2_free_ac_resource(*ac);
1096
1097inode_steal:
1098	status = ocfs2_steal_inode(osb, *ac);
1099	atomic_inc(&osb->s_num_inodes_stolen);
1100	if (status < 0) {
1101		if (status != -ENOSPC)
1102			mlog_errno(status);
1103		goto bail;
1104	}
1105
1106	status = 0;
1107bail:
1108	if ((status < 0) && *ac) {
1109		ocfs2_free_alloc_context(*ac);
1110		*ac = NULL;
1111	}
1112
1113	if (status)
1114		mlog_errno(status);
1115	return status;
1116}
1117
1118/* local alloc code has to do the same thing, so rather than do this
1119 * twice.. */
1120int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
1121				      struct ocfs2_alloc_context *ac)
1122{
1123	int status;
1124
1125	ac->ac_which = OCFS2_AC_USE_MAIN;
1126	ac->ac_group_search = ocfs2_cluster_group_search;
1127
1128	status = ocfs2_reserve_suballoc_bits(osb, ac,
1129					     GLOBAL_BITMAP_SYSTEM_INODE,
1130					     OCFS2_INVALID_SLOT, NULL,
1131					     ALLOC_NEW_GROUP);
1132	if (status < 0 && status != -ENOSPC)
1133		mlog_errno(status);
1134
1135	return status;
1136}
1137
1138/* Callers don't need to care which bitmap (local alloc or main) to
1139 * use so we figure it out for them, but unfortunately this clutters
1140 * things a bit. */
1141static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
1142					     u32 bits_wanted, u64 max_block,
1143					     int flags,
1144					     struct ocfs2_alloc_context **ac)
1145{
1146	int status, ret = 0;
1147	int retried = 0;
1148
1149	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1150	if (!(*ac)) {
1151		status = -ENOMEM;
1152		mlog_errno(status);
1153		goto bail;
1154	}
1155
1156	(*ac)->ac_bits_wanted = bits_wanted;
1157	(*ac)->ac_max_block = max_block;
1158
1159	status = -ENOSPC;
1160	if (!(flags & ALLOC_GROUPS_FROM_GLOBAL) &&
1161	    ocfs2_alloc_should_use_local(osb, bits_wanted)) {
1162		status = ocfs2_reserve_local_alloc_bits(osb,
1163							bits_wanted,
1164							*ac);
1165		if ((status < 0) && (status != -ENOSPC)) {
1166			mlog_errno(status);
1167			goto bail;
1168		}
1169	}
1170
1171	if (status == -ENOSPC) {
1172retry:
1173		status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
1174		/* Retry if there is sufficient space cached in truncate log */
1175		if (status == -ENOSPC && !retried) {
1176			retried = 1;
1177			ocfs2_inode_unlock((*ac)->ac_inode, 1);
1178			inode_unlock((*ac)->ac_inode);
1179
1180			ret = ocfs2_try_to_free_truncate_log(osb, bits_wanted);
1181			if (ret == 1) {
1182				iput((*ac)->ac_inode);
1183				(*ac)->ac_inode = NULL;
1184				goto retry;
1185			}
1186
1187			if (ret < 0)
1188				mlog_errno(ret);
1189
1190			inode_lock((*ac)->ac_inode);
1191			ret = ocfs2_inode_lock((*ac)->ac_inode, NULL, 1);
1192			if (ret < 0) {
1193				mlog_errno(ret);
1194				inode_unlock((*ac)->ac_inode);
1195				iput((*ac)->ac_inode);
1196				(*ac)->ac_inode = NULL;
1197				goto bail;
1198			}
1199		}
1200		if (status < 0) {
1201			if (status != -ENOSPC)
1202				mlog_errno(status);
1203			goto bail;
1204		}
1205	}
1206
1207	status = 0;
1208bail:
1209	if ((status < 0) && *ac) {
1210		ocfs2_free_alloc_context(*ac);
1211		*ac = NULL;
1212	}
1213
1214	if (status)
1215		mlog_errno(status);
1216	return status;
1217}
1218
1219int ocfs2_reserve_clusters(struct ocfs2_super *osb,
1220			   u32 bits_wanted,
1221			   struct ocfs2_alloc_context **ac)
1222{
1223	return ocfs2_reserve_clusters_with_limit(osb, bits_wanted, 0,
1224						 ALLOC_NEW_GROUP, ac);
1225}
1226
1227/*
1228 * More or less lifted from ext3. I'll leave their description below:
1229 *
1230 * "For ext3 allocations, we must not reuse any blocks which are
1231 * allocated in the bitmap buffer's "last committed data" copy.  This
1232 * prevents deletes from freeing up the page for reuse until we have
1233 * committed the delete transaction.
1234 *
1235 * If we didn't do this, then deleting something and reallocating it as
1236 * data would allow the old block to be overwritten before the
1237 * transaction committed (because we force data to disk before commit).
1238 * This would lead to corruption if we crashed between overwriting the
1239 * data and committing the delete.
1240 *
1241 * @@@ We may want to make this allocation behaviour conditional on
1242 * data-writes at some point, and disable it for metadata allocations or
1243 * sync-data inodes."
1244 *
1245 * Note: OCFS2 already does this differently for metadata vs data
1246 * allocations, as those bitmaps are separate and undo access is never
1247 * called on a metadata group descriptor.
1248 */
1249static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
1250					 int nr)
1251{
1252	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1253	struct journal_head *jh;
1254	int ret;
1255
1256	if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
1257		return 0;
1258
1259	jh = jbd2_journal_grab_journal_head(bg_bh);
1260	if (!jh)
1261		return 1;
1262
1263	spin_lock(&jh->b_state_lock);
1264	bg = (struct ocfs2_group_desc *) jh->b_committed_data;
1265	if (bg)
1266		ret = !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
1267	else
1268		ret = 1;
1269	spin_unlock(&jh->b_state_lock);
1270	jbd2_journal_put_journal_head(jh);
1271
1272	return ret;
1273}
1274
1275static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
1276					     struct buffer_head *bg_bh,
1277					     unsigned int bits_wanted,
1278					     unsigned int total_bits,
1279					     struct ocfs2_suballoc_result *res)
1280{
1281	void *bitmap;
1282	u16 best_offset, best_size;
1283	int offset, start, found, status = 0;
1284	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1285
1286	/* Callers got this descriptor from
1287	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1288	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1289
1290	found = start = best_offset = best_size = 0;
1291	bitmap = bg->bg_bitmap;
1292
1293	while((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) != -1) {
1294		if (offset == total_bits)
1295			break;
1296
1297		if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
1298			/* We found a zero, but we can't use it as it
1299			 * hasn't been put to disk yet! */
1300			found = 0;
1301			start = offset + 1;
1302		} else if (offset == start) {
1303			/* we found a zero */
1304			found++;
1305			/* move start to the next bit to test */
1306			start++;
1307		} else {
1308			/* got a zero after some ones */
1309			found = 1;
1310			start = offset + 1;
1311		}
1312		if (found > best_size) {
1313			best_size = found;
1314			best_offset = start - found;
1315		}
1316		/* we got everything we needed */
1317		if (found == bits_wanted) {
1318			/* mlog(0, "Found it all!\n"); */
1319			break;
1320		}
1321	}
1322
1323	if (best_size) {
1324		res->sr_bit_offset = best_offset;
1325		res->sr_bits = best_size;
1326	} else {
1327		status = -ENOSPC;
1328		/* No error log here -- see the comment above
1329		 * ocfs2_test_bg_bit_allocatable */
1330	}
1331
1332	return status;
1333}
1334
1335int ocfs2_block_group_set_bits(handle_t *handle,
1336					     struct inode *alloc_inode,
1337					     struct ocfs2_group_desc *bg,
1338					     struct buffer_head *group_bh,
1339					     unsigned int bit_off,
1340					     unsigned int num_bits)
1341{
1342	int status;
1343	void *bitmap = bg->bg_bitmap;
1344	int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1345
1346	/* All callers get the descriptor via
1347	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1348	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1349	BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
1350
1351	trace_ocfs2_block_group_set_bits(bit_off, num_bits);
1352
1353	if (ocfs2_is_cluster_bitmap(alloc_inode))
1354		journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1355
1356	status = ocfs2_journal_access_gd(handle,
1357					 INODE_CACHE(alloc_inode),
1358					 group_bh,
1359					 journal_type);
1360	if (status < 0) {
1361		mlog_errno(status);
1362		goto bail;
1363	}
1364
1365	le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
1366	if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
1367		return ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit count %u but claims %u are freed. num_bits %d\n",
1368				   (unsigned long long)le64_to_cpu(bg->bg_blkno),
1369				   le16_to_cpu(bg->bg_bits),
1370				   le16_to_cpu(bg->bg_free_bits_count),
1371				   num_bits);
1372	}
1373	while(num_bits--)
1374		ocfs2_set_bit(bit_off++, bitmap);
1375
1376	ocfs2_journal_dirty(handle, group_bh);
1377
1378bail:
1379	return status;
1380}
1381
1382/* find the one with the most empty bits */
1383static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
1384{
1385	u16 curr, best;
1386
1387	BUG_ON(!cl->cl_next_free_rec);
1388
1389	best = curr = 0;
1390	while (curr < le16_to_cpu(cl->cl_next_free_rec)) {
1391		if (le32_to_cpu(cl->cl_recs[curr].c_free) >
1392		    le32_to_cpu(cl->cl_recs[best].c_free))
1393			best = curr;
1394		curr++;
1395	}
1396
1397	BUG_ON(best >= le16_to_cpu(cl->cl_next_free_rec));
1398	return best;
1399}
1400
1401static int ocfs2_relink_block_group(handle_t *handle,
1402				    struct inode *alloc_inode,
1403				    struct buffer_head *fe_bh,
1404				    struct buffer_head *bg_bh,
1405				    struct buffer_head *prev_bg_bh,
1406				    u16 chain)
1407{
1408	int status;
1409	/* there is a really tiny chance the journal calls could fail,
1410	 * but we wouldn't want inconsistent blocks in *any* case. */
1411	u64 bg_ptr, prev_bg_ptr;
1412	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
1413	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1414	struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
1415
1416	/* The caller got these descriptors from
1417	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1418	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1419	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(prev_bg));
1420
1421	trace_ocfs2_relink_block_group(
1422		(unsigned long long)le64_to_cpu(fe->i_blkno), chain,
1423		(unsigned long long)le64_to_cpu(bg->bg_blkno),
1424		(unsigned long long)le64_to_cpu(prev_bg->bg_blkno));
1425
1426	bg_ptr = le64_to_cpu(bg->bg_next_group);
1427	prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
1428
1429	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1430					 prev_bg_bh,
1431					 OCFS2_JOURNAL_ACCESS_WRITE);
1432	if (status < 0)
1433		goto out;
1434
1435	prev_bg->bg_next_group = bg->bg_next_group;
1436	ocfs2_journal_dirty(handle, prev_bg_bh);
1437
1438	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1439					 bg_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1440	if (status < 0)
1441		goto out_rollback_prev_bg;
1442
1443	bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
1444	ocfs2_journal_dirty(handle, bg_bh);
1445
1446	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
1447					 fe_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1448	if (status < 0)
1449		goto out_rollback_bg;
1450
1451	fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
1452	ocfs2_journal_dirty(handle, fe_bh);
1453
1454out:
1455	if (status < 0)
1456		mlog_errno(status);
1457	return status;
1458
1459out_rollback_bg:
1460	bg->bg_next_group = cpu_to_le64(bg_ptr);
1461out_rollback_prev_bg:
1462	prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
1463	goto out;
1464}
1465
1466static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
1467						     u32 wanted)
1468{
1469	return le16_to_cpu(bg->bg_free_bits_count) > wanted;
1470}
1471
1472/* return 0 on success, -ENOSPC to keep searching and any other < 0
1473 * value on error. */
1474static int ocfs2_cluster_group_search(struct inode *inode,
1475				      struct buffer_head *group_bh,
1476				      u32 bits_wanted, u32 min_bits,
1477				      u64 max_block,
1478				      struct ocfs2_suballoc_result *res)
1479{
1480	int search = -ENOSPC;
1481	int ret;
1482	u64 blkoff;
1483	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
1484	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1485	unsigned int max_bits, gd_cluster_off;
1486
1487	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1488
1489	if (gd->bg_free_bits_count) {
1490		max_bits = le16_to_cpu(gd->bg_bits);
1491
1492		/* Tail groups in cluster bitmaps which aren't cpg
1493		 * aligned are prone to partial extension by a failed
1494		 * fs resize. If the file system resize never got to
1495		 * update the dinode cluster count, then we don't want
1496		 * to trust any clusters past it, regardless of what
1497		 * the group descriptor says. */
1498		gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
1499							  le64_to_cpu(gd->bg_blkno));
1500		if ((gd_cluster_off + max_bits) >
1501		    OCFS2_I(inode)->ip_clusters) {
1502			max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
1503			trace_ocfs2_cluster_group_search_wrong_max_bits(
1504				(unsigned long long)le64_to_cpu(gd->bg_blkno),
1505				le16_to_cpu(gd->bg_bits),
1506				OCFS2_I(inode)->ip_clusters, max_bits);
1507		}
1508
1509		ret = ocfs2_block_group_find_clear_bits(osb,
1510							group_bh, bits_wanted,
1511							max_bits, res);
1512		if (ret)
1513			return ret;
1514
1515		if (max_block) {
1516			blkoff = ocfs2_clusters_to_blocks(inode->i_sb,
1517							  gd_cluster_off +
1518							  res->sr_bit_offset +
1519							  res->sr_bits);
1520			trace_ocfs2_cluster_group_search_max_block(
1521				(unsigned long long)blkoff,
1522				(unsigned long long)max_block);
1523			if (blkoff > max_block)
1524				return -ENOSPC;
1525		}
1526
1527		/* ocfs2_block_group_find_clear_bits() might
1528		 * return success, but we still want to return
1529		 * -ENOSPC unless it found the minimum number
1530		 * of bits. */
1531		if (min_bits <= res->sr_bits)
1532			search = 0; /* success */
1533		else if (res->sr_bits) {
1534			/*
1535			 * Don't show bits which we'll be returning
1536			 * for allocation to the local alloc bitmap.
1537			 */
1538			ocfs2_local_alloc_seen_free_bits(osb, res->sr_bits);
1539		}
1540	}
1541
1542	return search;
1543}
1544
1545static int ocfs2_block_group_search(struct inode *inode,
1546				    struct buffer_head *group_bh,
1547				    u32 bits_wanted, u32 min_bits,
1548				    u64 max_block,
1549				    struct ocfs2_suballoc_result *res)
1550{
1551	int ret = -ENOSPC;
1552	u64 blkoff;
1553	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
1554
1555	BUG_ON(min_bits != 1);
1556	BUG_ON(ocfs2_is_cluster_bitmap(inode));
1557
1558	if (bg->bg_free_bits_count) {
1559		ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1560							group_bh, bits_wanted,
1561							le16_to_cpu(bg->bg_bits),
1562							res);
1563		if (!ret && max_block) {
1564			blkoff = le64_to_cpu(bg->bg_blkno) +
1565				res->sr_bit_offset + res->sr_bits;
1566			trace_ocfs2_block_group_search_max_block(
1567				(unsigned long long)blkoff,
1568				(unsigned long long)max_block);
1569			if (blkoff > max_block)
1570				ret = -ENOSPC;
1571		}
1572	}
1573
1574	return ret;
1575}
1576
1577int ocfs2_alloc_dinode_update_counts(struct inode *inode,
1578				       handle_t *handle,
1579				       struct buffer_head *di_bh,
1580				       u32 num_bits,
1581				       u16 chain)
1582{
1583	int ret;
1584	u32 tmp_used;
1585	struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1586	struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &di->id2.i_chain;
1587
1588	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
1589				      OCFS2_JOURNAL_ACCESS_WRITE);
1590	if (ret < 0) {
1591		mlog_errno(ret);
1592		goto out;
1593	}
1594
1595	tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1596	di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
1597	le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
1598	ocfs2_journal_dirty(handle, di_bh);
1599
1600out:
1601	return ret;
1602}
1603
1604void ocfs2_rollback_alloc_dinode_counts(struct inode *inode,
1605				       struct buffer_head *di_bh,
1606				       u32 num_bits,
1607				       u16 chain)
1608{
1609	u32 tmp_used;
1610	struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1611	struct ocfs2_chain_list *cl;
1612
1613	cl = (struct ocfs2_chain_list *)&di->id2.i_chain;
1614	tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1615	di->id1.bitmap1.i_used = cpu_to_le32(tmp_used - num_bits);
1616	le32_add_cpu(&cl->cl_recs[chain].c_free, num_bits);
1617}
1618
1619static int ocfs2_bg_discontig_fix_by_rec(struct ocfs2_suballoc_result *res,
1620					 struct ocfs2_extent_rec *rec,
1621					 struct ocfs2_chain_list *cl)
1622{
1623	unsigned int bpc = le16_to_cpu(cl->cl_bpc);
1624	unsigned int bitoff = le32_to_cpu(rec->e_cpos) * bpc;
1625	unsigned int bitcount = le16_to_cpu(rec->e_leaf_clusters) * bpc;
1626
1627	if (res->sr_bit_offset < bitoff)
1628		return 0;
1629	if (res->sr_bit_offset >= (bitoff + bitcount))
1630		return 0;
1631	res->sr_blkno = le64_to_cpu(rec->e_blkno) +
1632		(res->sr_bit_offset - bitoff);
1633	if ((res->sr_bit_offset + res->sr_bits) > (bitoff + bitcount))
1634		res->sr_bits = (bitoff + bitcount) - res->sr_bit_offset;
1635	return 1;
1636}
1637
1638static void ocfs2_bg_discontig_fix_result(struct ocfs2_alloc_context *ac,
1639					  struct ocfs2_group_desc *bg,
1640					  struct ocfs2_suballoc_result *res)
1641{
1642	int i;
1643	u64 bg_blkno = res->sr_bg_blkno;  /* Save off */
1644	struct ocfs2_extent_rec *rec;
1645	struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1646	struct ocfs2_chain_list *cl = &di->id2.i_chain;
1647
1648	if (ocfs2_is_cluster_bitmap(ac->ac_inode)) {
1649		res->sr_blkno = 0;
1650		return;
1651	}
1652
1653	res->sr_blkno = res->sr_bg_blkno + res->sr_bit_offset;
1654	res->sr_bg_blkno = 0;  /* Clear it for contig block groups */
1655	if (!ocfs2_supports_discontig_bg(OCFS2_SB(ac->ac_inode->i_sb)) ||
1656	    !bg->bg_list.l_next_free_rec)
1657		return;
1658
1659	for (i = 0; i < le16_to_cpu(bg->bg_list.l_next_free_rec); i++) {
1660		rec = &bg->bg_list.l_recs[i];
1661		if (ocfs2_bg_discontig_fix_by_rec(res, rec, cl)) {
1662			res->sr_bg_blkno = bg_blkno;  /* Restore */
1663			break;
1664		}
1665	}
1666}
1667
1668static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
1669				  handle_t *handle,
1670				  u32 bits_wanted,
1671				  u32 min_bits,
1672				  struct ocfs2_suballoc_result *res,
1673				  u16 *bits_left)
1674{
1675	int ret;
1676	struct buffer_head *group_bh = NULL;
1677	struct ocfs2_group_desc *gd;
1678	struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1679	struct inode *alloc_inode = ac->ac_inode;
1680
1681	ret = ocfs2_read_group_descriptor(alloc_inode, di,
1682					  res->sr_bg_blkno, &group_bh);
1683	if (ret < 0) {
1684		mlog_errno(ret);
1685		return ret;
1686	}
1687
1688	gd = (struct ocfs2_group_desc *) group_bh->b_data;
1689	ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
1690				  ac->ac_max_block, res);
1691	if (ret < 0) {
1692		if (ret != -ENOSPC)
1693			mlog_errno(ret);
1694		goto out;
1695	}
1696
1697	if (!ret)
1698		ocfs2_bg_discontig_fix_result(ac, gd, res);
1699
1700	/*
1701	 * sr_bg_blkno might have been changed by
1702	 * ocfs2_bg_discontig_fix_result
1703	 */
1704	res->sr_bg_stable_blkno = group_bh->b_blocknr;
1705
1706	if (ac->ac_find_loc_only)
1707		goto out_loc_only;
1708
1709	ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
1710					       res->sr_bits,
1711					       le16_to_cpu(gd->bg_chain));
1712	if (ret < 0) {
1713		mlog_errno(ret);
1714		goto out;
1715	}
1716
1717	ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
1718					 res->sr_bit_offset, res->sr_bits);
1719	if (ret < 0) {
1720		ocfs2_rollback_alloc_dinode_counts(alloc_inode, ac->ac_bh,
1721					       res->sr_bits,
1722					       le16_to_cpu(gd->bg_chain));
1723		mlog_errno(ret);
1724	}
1725
1726out_loc_only:
1727	*bits_left = le16_to_cpu(gd->bg_free_bits_count);
1728
1729out:
1730	brelse(group_bh);
1731
1732	return ret;
1733}
1734
1735static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
1736			      handle_t *handle,
1737			      u32 bits_wanted,
1738			      u32 min_bits,
1739			      struct ocfs2_suballoc_result *res,
1740			      u16 *bits_left)
1741{
1742	int status;
1743	u16 chain;
1744	u64 next_group;
1745	struct inode *alloc_inode = ac->ac_inode;
1746	struct buffer_head *group_bh = NULL;
1747	struct buffer_head *prev_group_bh = NULL;
1748	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1749	struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1750	struct ocfs2_group_desc *bg;
1751
1752	chain = ac->ac_chain;
1753	trace_ocfs2_search_chain_begin(
1754		(unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
1755		bits_wanted, chain);
1756
1757	status = ocfs2_read_group_descriptor(alloc_inode, fe,
1758					     le64_to_cpu(cl->cl_recs[chain].c_blkno),
1759					     &group_bh);
1760	if (status < 0) {
1761		mlog_errno(status);
1762		goto bail;
1763	}
1764	bg = (struct ocfs2_group_desc *) group_bh->b_data;
1765
1766	status = -ENOSPC;
1767	/* for now, the chain search is a bit simplistic. We just use
1768	 * the 1st group with any empty bits. */
1769	while ((status = ac->ac_group_search(alloc_inode, group_bh,
1770					     bits_wanted, min_bits,
1771					     ac->ac_max_block,
1772					     res)) == -ENOSPC) {
1773		if (!bg->bg_next_group)
1774			break;
1775
1776		brelse(prev_group_bh);
1777		prev_group_bh = NULL;
1778
1779		next_group = le64_to_cpu(bg->bg_next_group);
1780		prev_group_bh = group_bh;
1781		group_bh = NULL;
1782		status = ocfs2_read_group_descriptor(alloc_inode, fe,
1783						     next_group, &group_bh);
1784		if (status < 0) {
1785			mlog_errno(status);
1786			goto bail;
1787		}
1788		bg = (struct ocfs2_group_desc *) group_bh->b_data;
1789	}
1790	if (status < 0) {
1791		if (status != -ENOSPC)
1792			mlog_errno(status);
1793		goto bail;
1794	}
1795
1796	trace_ocfs2_search_chain_succ(
1797		(unsigned long long)le64_to_cpu(bg->bg_blkno), res->sr_bits);
1798
1799	res->sr_bg_blkno = le64_to_cpu(bg->bg_blkno);
1800
1801	BUG_ON(res->sr_bits == 0);
1802	if (!status)
1803		ocfs2_bg_discontig_fix_result(ac, bg, res);
1804
1805	/*
1806	 * sr_bg_blkno might have been changed by
1807	 * ocfs2_bg_discontig_fix_result
1808	 */
1809	res->sr_bg_stable_blkno = group_bh->b_blocknr;
1810
1811	/*
1812	 * Keep track of previous block descriptor read. When
1813	 * we find a target, if we have read more than X
1814	 * number of descriptors, and the target is reasonably
1815	 * empty, relink him to top of his chain.
1816	 *
1817	 * We've read 0 extra blocks and only send one more to
1818	 * the transaction, yet the next guy to search has a
1819	 * much easier time.
1820	 *
1821	 * Do this *after* figuring out how many bits we're taking out
1822	 * of our target group.
1823	 */
1824	if (!ac->ac_disable_chain_relink &&
1825	    (prev_group_bh) &&
1826	    (ocfs2_block_group_reasonably_empty(bg, res->sr_bits))) {
1827		status = ocfs2_relink_block_group(handle, alloc_inode,
1828						  ac->ac_bh, group_bh,
1829						  prev_group_bh, chain);
1830		if (status < 0) {
1831			mlog_errno(status);
1832			goto bail;
1833		}
1834	}
1835
1836	if (ac->ac_find_loc_only)
1837		goto out_loc_only;
1838
1839	status = ocfs2_alloc_dinode_update_counts(alloc_inode, handle,
1840						  ac->ac_bh, res->sr_bits,
1841						  chain);
1842	if (status) {
1843		mlog_errno(status);
1844		goto bail;
1845	}
1846
1847	status = ocfs2_block_group_set_bits(handle,
1848					    alloc_inode,
1849					    bg,
1850					    group_bh,
1851					    res->sr_bit_offset,
1852					    res->sr_bits);
1853	if (status < 0) {
1854		ocfs2_rollback_alloc_dinode_counts(alloc_inode,
1855					ac->ac_bh, res->sr_bits, chain);
1856		mlog_errno(status);
1857		goto bail;
1858	}
1859
1860	trace_ocfs2_search_chain_end(
1861			(unsigned long long)le64_to_cpu(fe->i_blkno),
1862			res->sr_bits);
1863
1864out_loc_only:
1865	*bits_left = le16_to_cpu(bg->bg_free_bits_count);
1866bail:
1867	brelse(group_bh);
1868	brelse(prev_group_bh);
1869
1870	if (status)
1871		mlog_errno(status);
1872	return status;
1873}
1874
1875/* will give out up to bits_wanted contiguous bits. */
1876static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
1877				     handle_t *handle,
1878				     u32 bits_wanted,
1879				     u32 min_bits,
1880				     struct ocfs2_suballoc_result *res)
1881{
1882	int status;
1883	u16 victim, i;
1884	u16 bits_left = 0;
1885	u64 hint = ac->ac_last_group;
1886	struct ocfs2_chain_list *cl;
1887	struct ocfs2_dinode *fe;
1888
1889	BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1890	BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1891	BUG_ON(!ac->ac_bh);
1892
1893	fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1894
1895	/* The bh was validated by the inode read during
1896	 * ocfs2_reserve_suballoc_bits().  Any corruption is a code bug. */
1897	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
1898
1899	if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1900	    le32_to_cpu(fe->id1.bitmap1.i_total)) {
1901		status = ocfs2_error(ac->ac_inode->i_sb,
1902				     "Chain allocator dinode %llu has %u used bits but only %u total\n",
1903				     (unsigned long long)le64_to_cpu(fe->i_blkno),
1904				     le32_to_cpu(fe->id1.bitmap1.i_used),
1905				     le32_to_cpu(fe->id1.bitmap1.i_total));
1906		goto bail;
1907	}
1908
1909	res->sr_bg_blkno = hint;
1910	if (res->sr_bg_blkno) {
1911		/* Attempt to short-circuit the usual search mechanism
1912		 * by jumping straight to the most recently used
1913		 * allocation group. This helps us maintain some
1914		 * contiguousness across allocations. */
1915		status = ocfs2_search_one_group(ac, handle, bits_wanted,
1916						min_bits, res, &bits_left);
1917		if (!status)
1918			goto set_hint;
1919		if (status < 0 && status != -ENOSPC) {
1920			mlog_errno(status);
1921			goto bail;
1922		}
1923	}
1924
1925	cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1926
1927	victim = ocfs2_find_victim_chain(cl);
1928	ac->ac_chain = victim;
1929
1930	status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1931				    res, &bits_left);
1932	if (!status) {
1933		if (ocfs2_is_cluster_bitmap(ac->ac_inode))
1934			hint = res->sr_bg_blkno;
1935		else
1936			hint = ocfs2_group_from_res(res);
1937		goto set_hint;
1938	}
1939	if (status < 0 && status != -ENOSPC) {
1940		mlog_errno(status);
1941		goto bail;
1942	}
1943
1944	trace_ocfs2_claim_suballoc_bits(victim);
1945
1946	/* If we didn't pick a good victim, then just default to
1947	 * searching each chain in order. Don't allow chain relinking
1948	 * because we only calculate enough journal credits for one
1949	 * relink per alloc. */
1950	ac->ac_disable_chain_relink = 1;
1951	for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
1952		if (i == victim)
1953			continue;
1954		if (!cl->cl_recs[i].c_free)
1955			continue;
1956
1957		ac->ac_chain = i;
1958		status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1959					    res, &bits_left);
1960		if (!status) {
1961			hint = ocfs2_group_from_res(res);
1962			break;
1963		}
1964		if (status < 0 && status != -ENOSPC) {
1965			mlog_errno(status);
1966			goto bail;
1967		}
1968	}
1969
1970set_hint:
1971	if (status != -ENOSPC) {
1972		/* If the next search of this group is not likely to
1973		 * yield a suitable extent, then we reset the last
1974		 * group hint so as to not waste a disk read */
1975		if (bits_left < min_bits)
1976			ac->ac_last_group = 0;
1977		else
1978			ac->ac_last_group = hint;
1979	}
1980
1981bail:
1982	if (status)
1983		mlog_errno(status);
1984	return status;
1985}
1986
1987int ocfs2_claim_metadata(handle_t *handle,
1988			 struct ocfs2_alloc_context *ac,
1989			 u32 bits_wanted,
1990			 u64 *suballoc_loc,
1991			 u16 *suballoc_bit_start,
1992			 unsigned int *num_bits,
1993			 u64 *blkno_start)
1994{
1995	int status;
1996	struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
1997
1998	BUG_ON(!ac);
1999	BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
2000	BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
2001
2002	status = ocfs2_claim_suballoc_bits(ac,
2003					   handle,
2004					   bits_wanted,
2005					   1,
2006					   &res);
2007	if (status < 0) {
2008		mlog_errno(status);
2009		goto bail;
2010	}
2011	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2012
2013	*suballoc_loc = res.sr_bg_blkno;
2014	*suballoc_bit_start = res.sr_bit_offset;
2015	*blkno_start = res.sr_blkno;
2016	ac->ac_bits_given += res.sr_bits;
2017	*num_bits = res.sr_bits;
2018	status = 0;
2019bail:
2020	if (status)
2021		mlog_errno(status);
2022	return status;
2023}
2024
2025static void ocfs2_init_inode_ac_group(struct inode *dir,
2026				      struct buffer_head *parent_di_bh,
2027				      struct ocfs2_alloc_context *ac)
2028{
2029	struct ocfs2_dinode *di = (struct ocfs2_dinode *)parent_di_bh->b_data;
2030	/*
2031	 * Try to allocate inodes from some specific group.
2032	 *
2033	 * If the parent dir has recorded the last group used in allocation,
2034	 * cool, use it. Otherwise if we try to allocate new inode from the
2035	 * same slot the parent dir belongs to, use the same chunk.
2036	 *
2037	 * We are very careful here to avoid the mistake of setting
2038	 * ac_last_group to a group descriptor from a different (unlocked) slot.
2039	 */
2040	if (OCFS2_I(dir)->ip_last_used_group &&
2041	    OCFS2_I(dir)->ip_last_used_slot == ac->ac_alloc_slot)
2042		ac->ac_last_group = OCFS2_I(dir)->ip_last_used_group;
2043	else if (le16_to_cpu(di->i_suballoc_slot) == ac->ac_alloc_slot) {
2044		if (di->i_suballoc_loc)
2045			ac->ac_last_group = le64_to_cpu(di->i_suballoc_loc);
2046		else
2047			ac->ac_last_group = ocfs2_which_suballoc_group(
2048					le64_to_cpu(di->i_blkno),
2049					le16_to_cpu(di->i_suballoc_bit));
2050	}
2051}
2052
2053static inline void ocfs2_save_inode_ac_group(struct inode *dir,
2054					     struct ocfs2_alloc_context *ac)
2055{
2056	OCFS2_I(dir)->ip_last_used_group = ac->ac_last_group;
2057	OCFS2_I(dir)->ip_last_used_slot = ac->ac_alloc_slot;
2058}
2059
2060int ocfs2_find_new_inode_loc(struct inode *dir,
2061			     struct buffer_head *parent_fe_bh,
2062			     struct ocfs2_alloc_context *ac,
2063			     u64 *fe_blkno)
2064{
2065	int ret;
2066	handle_t *handle = NULL;
2067	struct ocfs2_suballoc_result *res;
2068
2069	BUG_ON(!ac);
2070	BUG_ON(ac->ac_bits_given != 0);
2071	BUG_ON(ac->ac_bits_wanted != 1);
2072	BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2073
2074	res = kzalloc(sizeof(*res), GFP_NOFS);
2075	if (res == NULL) {
2076		ret = -ENOMEM;
2077		mlog_errno(ret);
2078		goto out;
2079	}
2080
2081	ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2082
2083	/*
2084	 * The handle started here is for chain relink. Alternatively,
2085	 * we could just disable relink for these calls.
2086	 */
2087	handle = ocfs2_start_trans(OCFS2_SB(dir->i_sb), OCFS2_SUBALLOC_ALLOC);
2088	if (IS_ERR(handle)) {
2089		ret = PTR_ERR(handle);
2090		handle = NULL;
2091		mlog_errno(ret);
2092		goto out;
2093	}
2094
2095	/*
2096	 * This will instruct ocfs2_claim_suballoc_bits and
2097	 * ocfs2_search_one_group to search but save actual allocation
2098	 * for later.
2099	 */
2100	ac->ac_find_loc_only = 1;
2101
2102	ret = ocfs2_claim_suballoc_bits(ac, handle, 1, 1, res);
2103	if (ret < 0) {
2104		mlog_errno(ret);
2105		goto out;
2106	}
2107
2108	ac->ac_find_loc_priv = res;
2109	*fe_blkno = res->sr_blkno;
2110	ocfs2_update_inode_fsync_trans(handle, dir, 0);
2111out:
2112	if (handle)
2113		ocfs2_commit_trans(OCFS2_SB(dir->i_sb), handle);
2114
2115	if (ret)
2116		kfree(res);
2117
2118	return ret;
2119}
2120
2121int ocfs2_claim_new_inode_at_loc(handle_t *handle,
2122				 struct inode *dir,
2123				 struct ocfs2_alloc_context *ac,
2124				 u64 *suballoc_loc,
2125				 u16 *suballoc_bit,
2126				 u64 di_blkno)
2127{
2128	int ret;
2129	u16 chain;
2130	struct ocfs2_suballoc_result *res = ac->ac_find_loc_priv;
2131	struct buffer_head *bg_bh = NULL;
2132	struct ocfs2_group_desc *bg;
2133	struct ocfs2_dinode *di = (struct ocfs2_dinode *) ac->ac_bh->b_data;
2134
2135	/*
2136	 * Since di_blkno is being passed back in, we check for any
2137	 * inconsistencies which may have happened between
2138	 * calls. These are code bugs as di_blkno is not expected to
2139	 * change once returned from ocfs2_find_new_inode_loc()
2140	 */
2141	BUG_ON(res->sr_blkno != di_blkno);
2142
2143	ret = ocfs2_read_group_descriptor(ac->ac_inode, di,
2144					  res->sr_bg_stable_blkno, &bg_bh);
2145	if (ret) {
2146		mlog_errno(ret);
2147		goto out;
2148	}
2149
2150	bg = (struct ocfs2_group_desc *) bg_bh->b_data;
2151	chain = le16_to_cpu(bg->bg_chain);
2152
2153	ret = ocfs2_alloc_dinode_update_counts(ac->ac_inode, handle,
2154					       ac->ac_bh, res->sr_bits,
2155					       chain);
2156	if (ret) {
2157		mlog_errno(ret);
2158		goto out;
2159	}
2160
2161	ret = ocfs2_block_group_set_bits(handle,
2162					 ac->ac_inode,
2163					 bg,
2164					 bg_bh,
2165					 res->sr_bit_offset,
2166					 res->sr_bits);
2167	if (ret < 0) {
2168		ocfs2_rollback_alloc_dinode_counts(ac->ac_inode,
2169					       ac->ac_bh, res->sr_bits, chain);
2170		mlog_errno(ret);
2171		goto out;
2172	}
2173
2174	trace_ocfs2_claim_new_inode_at_loc((unsigned long long)di_blkno,
2175					   res->sr_bits);
2176
2177	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2178
2179	BUG_ON(res->sr_bits != 1);
2180
2181	*suballoc_loc = res->sr_bg_blkno;
2182	*suballoc_bit = res->sr_bit_offset;
2183	ac->ac_bits_given++;
2184	ocfs2_save_inode_ac_group(dir, ac);
2185
2186out:
2187	brelse(bg_bh);
2188
2189	return ret;
2190}
2191
2192int ocfs2_claim_new_inode(handle_t *handle,
2193			  struct inode *dir,
2194			  struct buffer_head *parent_fe_bh,
2195			  struct ocfs2_alloc_context *ac,
2196			  u64 *suballoc_loc,
2197			  u16 *suballoc_bit,
2198			  u64 *fe_blkno)
2199{
2200	int status;
2201	struct ocfs2_suballoc_result res;
2202
2203	BUG_ON(!ac);
2204	BUG_ON(ac->ac_bits_given != 0);
2205	BUG_ON(ac->ac_bits_wanted != 1);
2206	BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2207
2208	ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2209
2210	status = ocfs2_claim_suballoc_bits(ac,
2211					   handle,
2212					   1,
2213					   1,
2214					   &res);
2215	if (status < 0) {
2216		mlog_errno(status);
2217		goto bail;
2218	}
2219	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2220
2221	BUG_ON(res.sr_bits != 1);
2222
2223	*suballoc_loc = res.sr_bg_blkno;
2224	*suballoc_bit = res.sr_bit_offset;
2225	*fe_blkno = res.sr_blkno;
2226	ac->ac_bits_given++;
2227	ocfs2_save_inode_ac_group(dir, ac);
2228	status = 0;
2229bail:
2230	if (status)
2231		mlog_errno(status);
2232	return status;
2233}
2234
2235/* translate a group desc. blkno and it's bitmap offset into
2236 * disk cluster offset. */
2237static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
2238						   u64 bg_blkno,
2239						   u16 bg_bit_off)
2240{
2241	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2242	u32 cluster = 0;
2243
2244	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2245
2246	if (bg_blkno != osb->first_cluster_group_blkno)
2247		cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
2248	cluster += (u32) bg_bit_off;
2249	return cluster;
2250}
2251
2252/* given a cluster offset, calculate which block group it belongs to
2253 * and return that block offset. */
2254u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster)
2255{
2256	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2257	u32 group_no;
2258
2259	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2260
2261	group_no = cluster / osb->bitmap_cpg;
2262	if (!group_no)
2263		return osb->first_cluster_group_blkno;
2264	return ocfs2_clusters_to_blocks(inode->i_sb,
2265					group_no * osb->bitmap_cpg);
2266}
2267
2268/* given the block number of a cluster start, calculate which cluster
2269 * group and descriptor bitmap offset that corresponds to. */
2270static inline void ocfs2_block_to_cluster_group(struct inode *inode,
2271						u64 data_blkno,
2272						u64 *bg_blkno,
2273						u16 *bg_bit_off)
2274{
2275	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2276	u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
2277
2278	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2279
2280	*bg_blkno = ocfs2_which_cluster_group(inode,
2281					      data_cluster);
2282
2283	if (*bg_blkno == osb->first_cluster_group_blkno)
2284		*bg_bit_off = (u16) data_cluster;
2285	else
2286		*bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
2287							     data_blkno - *bg_blkno);
2288}
2289
2290/*
2291 * min_bits - minimum contiguous chunk from this total allocation we
2292 * can handle. set to what we asked for originally for a full
2293 * contig. allocation, set to '1' to indicate we can deal with extents
2294 * of any size.
2295 */
2296int __ocfs2_claim_clusters(handle_t *handle,
2297			   struct ocfs2_alloc_context *ac,
2298			   u32 min_clusters,
2299			   u32 max_clusters,
2300			   u32 *cluster_start,
2301			   u32 *num_clusters)
2302{
2303	int status;
2304	unsigned int bits_wanted = max_clusters;
2305	struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
2306	struct ocfs2_super *osb = OCFS2_SB(ac->ac_inode->i_sb);
2307
2308	BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
2309
2310	BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
2311	       && ac->ac_which != OCFS2_AC_USE_MAIN);
2312
2313	if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
2314		WARN_ON(min_clusters > 1);
2315
2316		status = ocfs2_claim_local_alloc_bits(osb,
2317						      handle,
2318						      ac,
2319						      bits_wanted,
2320						      cluster_start,
2321						      num_clusters);
2322		if (!status)
2323			atomic_inc(&osb->alloc_stats.local_data);
2324	} else {
2325		if (min_clusters > (osb->bitmap_cpg - 1)) {
2326			/* The only paths asking for contiguousness
2327			 * should know about this already. */
2328			mlog(ML_ERROR, "minimum allocation requested %u exceeds "
2329			     "group bitmap size %u!\n", min_clusters,
2330			     osb->bitmap_cpg);
2331			status = -ENOSPC;
2332			goto bail;
2333		}
2334		/* clamp the current request down to a realistic size. */
2335		if (bits_wanted > (osb->bitmap_cpg - 1))
2336			bits_wanted = osb->bitmap_cpg - 1;
2337
2338		status = ocfs2_claim_suballoc_bits(ac,
2339						   handle,
2340						   bits_wanted,
2341						   min_clusters,
2342						   &res);
2343		if (!status) {
2344			BUG_ON(res.sr_blkno); /* cluster alloc can't set */
2345			*cluster_start =
2346				ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
2347								 res.sr_bg_blkno,
2348								 res.sr_bit_offset);
2349			atomic_inc(&osb->alloc_stats.bitmap_data);
2350			*num_clusters = res.sr_bits;
2351		}
2352	}
2353	if (status < 0) {
2354		if (status != -ENOSPC)
2355			mlog_errno(status);
2356		goto bail;
2357	}
2358
2359	ac->ac_bits_given += *num_clusters;
2360
2361bail:
2362	if (status)
2363		mlog_errno(status);
2364	return status;
2365}
2366
2367int ocfs2_claim_clusters(handle_t *handle,
2368			 struct ocfs2_alloc_context *ac,
2369			 u32 min_clusters,
2370			 u32 *cluster_start,
2371			 u32 *num_clusters)
2372{
2373	unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
2374
2375	return __ocfs2_claim_clusters(handle, ac, min_clusters,
2376				      bits_wanted, cluster_start, num_clusters);
2377}
2378
2379static int ocfs2_block_group_clear_bits(handle_t *handle,
2380					struct inode *alloc_inode,
2381					struct ocfs2_group_desc *bg,
2382					struct buffer_head *group_bh,
2383					unsigned int bit_off,
2384					unsigned int num_bits,
2385					void (*undo_fn)(unsigned int bit,
2386							unsigned long *bmap))
2387{
2388	int status;
2389	unsigned int tmp;
2390	struct ocfs2_group_desc *undo_bg = NULL;
2391	struct journal_head *jh;
2392
2393	/* The caller got this descriptor from
2394	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
2395	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
2396
2397	trace_ocfs2_block_group_clear_bits(bit_off, num_bits);
2398
2399	BUG_ON(undo_fn && !ocfs2_is_cluster_bitmap(alloc_inode));
2400	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
2401					 group_bh,
2402					 undo_fn ?
2403					 OCFS2_JOURNAL_ACCESS_UNDO :
2404					 OCFS2_JOURNAL_ACCESS_WRITE);
2405	if (status < 0) {
2406		mlog_errno(status);
2407		goto bail;
2408	}
2409
2410	jh = bh2jh(group_bh);
2411	if (undo_fn) {
2412		spin_lock(&jh->b_state_lock);
2413		undo_bg = (struct ocfs2_group_desc *) jh->b_committed_data;
2414		BUG_ON(!undo_bg);
2415	}
2416
2417	tmp = num_bits;
2418	while(tmp--) {
2419		ocfs2_clear_bit((bit_off + tmp),
2420				(unsigned long *) bg->bg_bitmap);
2421		if (undo_fn)
2422			undo_fn(bit_off + tmp,
2423				(unsigned long *) undo_bg->bg_bitmap);
2424	}
2425	le16_add_cpu(&bg->bg_free_bits_count, num_bits);
2426	if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
2427		if (undo_fn)
2428			spin_unlock(&jh->b_state_lock);
2429		return ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit count %u but claims %u are freed. num_bits %d\n",
2430				   (unsigned long long)le64_to_cpu(bg->bg_blkno),
2431				   le16_to_cpu(bg->bg_bits),
2432				   le16_to_cpu(bg->bg_free_bits_count),
2433				   num_bits);
2434	}
2435
2436	if (undo_fn)
2437		spin_unlock(&jh->b_state_lock);
2438
2439	ocfs2_journal_dirty(handle, group_bh);
2440bail:
2441	return status;
2442}
2443
2444/*
2445 * expects the suballoc inode to already be locked.
2446 */
2447static int _ocfs2_free_suballoc_bits(handle_t *handle,
2448				     struct inode *alloc_inode,
2449				     struct buffer_head *alloc_bh,
2450				     unsigned int start_bit,
2451				     u64 bg_blkno,
2452				     unsigned int count,
2453				     void (*undo_fn)(unsigned int bit,
2454						     unsigned long *bitmap))
2455{
2456	int status = 0;
2457	u32 tmp_used;
2458	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
2459	struct ocfs2_chain_list *cl = &fe->id2.i_chain;
2460	struct buffer_head *group_bh = NULL;
2461	struct ocfs2_group_desc *group;
2462
2463	/* The alloc_bh comes from ocfs2_free_dinode() or
2464	 * ocfs2_free_clusters().  The callers have all locked the
2465	 * allocator and gotten alloc_bh from the lock call.  This
2466	 * validates the dinode buffer.  Any corruption that has happened
2467	 * is a code bug. */
2468	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
2469	BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
2470
2471	trace_ocfs2_free_suballoc_bits(
2472		(unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
2473		(unsigned long long)bg_blkno,
2474		start_bit, count);
2475
2476	status = ocfs2_read_group_descriptor(alloc_inode, fe, bg_blkno,
2477					     &group_bh);
2478	if (status < 0) {
2479		mlog_errno(status);
2480		goto bail;
2481	}
2482	group = (struct ocfs2_group_desc *) group_bh->b_data;
2483
2484	BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
2485
2486	status = ocfs2_block_group_clear_bits(handle, alloc_inode,
2487					      group, group_bh,
2488					      start_bit, count, undo_fn);
2489	if (status < 0) {
2490		mlog_errno(status);
2491		goto bail;
2492	}
2493
2494	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
2495					 alloc_bh, OCFS2_JOURNAL_ACCESS_WRITE);
2496	if (status < 0) {
2497		mlog_errno(status);
2498		ocfs2_block_group_set_bits(handle, alloc_inode, group, group_bh,
2499				start_bit, count);
2500		goto bail;
2501	}
2502
2503	le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
2504		     count);
2505	tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
2506	fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
2507	ocfs2_journal_dirty(handle, alloc_bh);
2508
2509bail:
2510	brelse(group_bh);
2511	return status;
2512}
2513
2514int ocfs2_free_suballoc_bits(handle_t *handle,
2515			     struct inode *alloc_inode,
2516			     struct buffer_head *alloc_bh,
2517			     unsigned int start_bit,
2518			     u64 bg_blkno,
2519			     unsigned int count)
2520{
2521	return _ocfs2_free_suballoc_bits(handle, alloc_inode, alloc_bh,
2522					 start_bit, bg_blkno, count, NULL);
2523}
2524
2525int ocfs2_free_dinode(handle_t *handle,
2526		      struct inode *inode_alloc_inode,
2527		      struct buffer_head *inode_alloc_bh,
2528		      struct ocfs2_dinode *di)
2529{
2530	u64 blk = le64_to_cpu(di->i_blkno);
2531	u16 bit = le16_to_cpu(di->i_suballoc_bit);
2532	u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
2533
2534	if (di->i_suballoc_loc)
2535		bg_blkno = le64_to_cpu(di->i_suballoc_loc);
2536	return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
2537					inode_alloc_bh, bit, bg_blkno, 1);
2538}
2539
2540static int _ocfs2_free_clusters(handle_t *handle,
2541				struct inode *bitmap_inode,
2542				struct buffer_head *bitmap_bh,
2543				u64 start_blk,
2544				unsigned int num_clusters,
2545				void (*undo_fn)(unsigned int bit,
2546						unsigned long *bitmap))
2547{
2548	int status;
2549	u16 bg_start_bit;
2550	u64 bg_blkno;
2551
2552	/* You can't ever have a contiguous set of clusters
2553	 * bigger than a block group bitmap so we never have to worry
2554	 * about looping on them.
2555	 * This is expensive. We can safely remove once this stuff has
2556	 * gotten tested really well. */
2557	BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb,
2558				ocfs2_blocks_to_clusters(bitmap_inode->i_sb,
2559							 start_blk)));
2560
2561
2562	ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
2563				     &bg_start_bit);
2564
2565	trace_ocfs2_free_clusters((unsigned long long)bg_blkno,
2566			(unsigned long long)start_blk,
2567			bg_start_bit, num_clusters);
2568
2569	status = _ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
2570					   bg_start_bit, bg_blkno,
2571					   num_clusters, undo_fn);
2572	if (status < 0) {
2573		mlog_errno(status);
2574		goto out;
2575	}
2576
2577	ocfs2_local_alloc_seen_free_bits(OCFS2_SB(bitmap_inode->i_sb),
2578					 num_clusters);
2579
2580out:
2581	return status;
2582}
2583
2584int ocfs2_free_clusters(handle_t *handle,
2585			struct inode *bitmap_inode,
2586			struct buffer_head *bitmap_bh,
2587			u64 start_blk,
2588			unsigned int num_clusters)
2589{
2590	return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2591				    start_blk, num_clusters,
2592				    _ocfs2_set_bit);
2593}
2594
2595/*
2596 * Give never-used clusters back to the global bitmap.  We don't need
2597 * to protect these bits in the undo buffer.
2598 */
2599int ocfs2_release_clusters(handle_t *handle,
2600			   struct inode *bitmap_inode,
2601			   struct buffer_head *bitmap_bh,
2602			   u64 start_blk,
2603			   unsigned int num_clusters)
2604{
2605	return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2606				    start_blk, num_clusters,
2607				    _ocfs2_clear_bit);
2608}
2609
2610/*
2611 * For a given allocation, determine which allocators will need to be
2612 * accessed, and lock them, reserving the appropriate number of bits.
2613 *
2614 * Sparse file systems call this from ocfs2_write_begin_nolock()
2615 * and ocfs2_allocate_unwritten_extents().
2616 *
2617 * File systems which don't support holes call this from
2618 * ocfs2_extend_allocation().
2619 */
2620int ocfs2_lock_allocators(struct inode *inode,
2621			  struct ocfs2_extent_tree *et,
2622			  u32 clusters_to_add, u32 extents_to_split,
2623			  struct ocfs2_alloc_context **data_ac,
2624			  struct ocfs2_alloc_context **meta_ac)
2625{
2626	int ret = 0, num_free_extents;
2627	unsigned int max_recs_needed = clusters_to_add + 2 * extents_to_split;
2628	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2629
2630	*meta_ac = NULL;
2631	if (data_ac)
2632		*data_ac = NULL;
2633
2634	BUG_ON(clusters_to_add != 0 && data_ac == NULL);
2635
2636	num_free_extents = ocfs2_num_free_extents(et);
2637	if (num_free_extents < 0) {
2638		ret = num_free_extents;
2639		mlog_errno(ret);
2640		goto out;
2641	}
2642
2643	/*
2644	 * Sparse allocation file systems need to be more conservative
2645	 * with reserving room for expansion - the actual allocation
2646	 * happens while we've got a journal handle open so re-taking
2647	 * a cluster lock (because we ran out of room for another
2648	 * extent) will violate ordering rules.
2649	 *
2650	 * Most of the time we'll only be seeing this 1 cluster at a time
2651	 * anyway.
2652	 *
2653	 * Always lock for any unwritten extents - we might want to
2654	 * add blocks during a split.
2655	 */
2656	if (!num_free_extents ||
2657	    (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed)) {
2658		ret = ocfs2_reserve_new_metadata(osb, et->et_root_el, meta_ac);
2659		if (ret < 0) {
2660			if (ret != -ENOSPC)
2661				mlog_errno(ret);
2662			goto out;
2663		}
2664	}
2665
2666	if (clusters_to_add == 0)
2667		goto out;
2668
2669	ret = ocfs2_reserve_clusters(osb, clusters_to_add, data_ac);
2670	if (ret < 0) {
2671		if (ret != -ENOSPC)
2672			mlog_errno(ret);
2673		goto out;
2674	}
2675
2676out:
2677	if (ret) {
2678		if (*meta_ac) {
2679			ocfs2_free_alloc_context(*meta_ac);
2680			*meta_ac = NULL;
2681		}
2682
2683		/*
2684		 * We cannot have an error and a non null *data_ac.
2685		 */
2686	}
2687
2688	return ret;
2689}
2690
2691/*
2692 * Read the inode specified by blkno to get suballoc_slot and
2693 * suballoc_bit.
2694 */
2695static int ocfs2_get_suballoc_slot_bit(struct ocfs2_super *osb, u64 blkno,
2696				       u16 *suballoc_slot, u64 *group_blkno,
2697				       u16 *suballoc_bit)
2698{
2699	int status;
2700	struct buffer_head *inode_bh = NULL;
2701	struct ocfs2_dinode *inode_fe;
2702
2703	trace_ocfs2_get_suballoc_slot_bit((unsigned long long)blkno);
2704
2705	/* dirty read disk */
2706	status = ocfs2_read_blocks_sync(osb, blkno, 1, &inode_bh);
2707	if (status < 0) {
2708		mlog(ML_ERROR, "read block %llu failed %d\n",
2709		     (unsigned long long)blkno, status);
2710		goto bail;
2711	}
2712
2713	inode_fe = (struct ocfs2_dinode *) inode_bh->b_data;
2714	if (!OCFS2_IS_VALID_DINODE(inode_fe)) {
2715		mlog(ML_ERROR, "invalid inode %llu requested\n",
2716		     (unsigned long long)blkno);
2717		status = -EINVAL;
2718		goto bail;
2719	}
2720
2721	if (le16_to_cpu(inode_fe->i_suballoc_slot) != (u16)OCFS2_INVALID_SLOT &&
2722	    (u32)le16_to_cpu(inode_fe->i_suballoc_slot) > osb->max_slots - 1) {
2723		mlog(ML_ERROR, "inode %llu has invalid suballoc slot %u\n",
2724		     (unsigned long long)blkno,
2725		     (u32)le16_to_cpu(inode_fe->i_suballoc_slot));
2726		status = -EINVAL;
2727		goto bail;
2728	}
2729
2730	if (suballoc_slot)
2731		*suballoc_slot = le16_to_cpu(inode_fe->i_suballoc_slot);
2732	if (suballoc_bit)
2733		*suballoc_bit = le16_to_cpu(inode_fe->i_suballoc_bit);
2734	if (group_blkno)
2735		*group_blkno = le64_to_cpu(inode_fe->i_suballoc_loc);
2736
2737bail:
2738	brelse(inode_bh);
2739
2740	if (status)
2741		mlog_errno(status);
2742	return status;
2743}
2744
2745/*
2746 * test whether bit is SET in allocator bitmap or not.  on success, 0
2747 * is returned and *res is 1 for SET; 0 otherwise.  when fails, errno
2748 * is returned and *res is meaningless.  Call this after you have
2749 * cluster locked against suballoc, or you may get a result based on
2750 * non-up2date contents
2751 */
2752static int ocfs2_test_suballoc_bit(struct ocfs2_super *osb,
2753				   struct inode *suballoc,
2754				   struct buffer_head *alloc_bh,
2755				   u64 group_blkno, u64 blkno,
2756				   u16 bit, int *res)
2757{
2758	struct ocfs2_dinode *alloc_di;
2759	struct ocfs2_group_desc *group;
2760	struct buffer_head *group_bh = NULL;
2761	u64 bg_blkno;
2762	int status;
2763
2764	trace_ocfs2_test_suballoc_bit((unsigned long long)blkno,
2765				      (unsigned int)bit);
2766
2767	alloc_di = (struct ocfs2_dinode *)alloc_bh->b_data;
2768	if ((bit + 1) > ocfs2_bits_per_group(&alloc_di->id2.i_chain)) {
2769		mlog(ML_ERROR, "suballoc bit %u out of range of %u\n",
2770		     (unsigned int)bit,
2771		     ocfs2_bits_per_group(&alloc_di->id2.i_chain));
2772		status = -EINVAL;
2773		goto bail;
2774	}
2775
2776	bg_blkno = group_blkno ? group_blkno :
2777		   ocfs2_which_suballoc_group(blkno, bit);
2778	status = ocfs2_read_group_descriptor(suballoc, alloc_di, bg_blkno,
2779					     &group_bh);
2780	if (status < 0) {
2781		mlog(ML_ERROR, "read group %llu failed %d\n",
2782		     (unsigned long long)bg_blkno, status);
2783		goto bail;
2784	}
2785
2786	group = (struct ocfs2_group_desc *) group_bh->b_data;
2787	*res = ocfs2_test_bit(bit, (unsigned long *)group->bg_bitmap);
2788
2789bail:
2790	brelse(group_bh);
2791
2792	if (status)
2793		mlog_errno(status);
2794	return status;
2795}
2796
2797/*
2798 * Test if the bit representing this inode (blkno) is set in the
2799 * suballocator.
2800 *
2801 * On success, 0 is returned and *res is 1 for SET; 0 otherwise.
2802 *
2803 * In the event of failure, a negative value is returned and *res is
2804 * meaningless.
2805 *
2806 * Callers must make sure to hold nfs_sync_lock to prevent
2807 * ocfs2_delete_inode() on another node from accessing the same
2808 * suballocator concurrently.
2809 */
2810int ocfs2_test_inode_bit(struct ocfs2_super *osb, u64 blkno, int *res)
2811{
2812	int status;
2813	u64 group_blkno = 0;
2814	u16 suballoc_bit = 0, suballoc_slot = 0;
2815	struct inode *inode_alloc_inode;
2816	struct buffer_head *alloc_bh = NULL;
2817
2818	trace_ocfs2_test_inode_bit((unsigned long long)blkno);
2819
2820	status = ocfs2_get_suballoc_slot_bit(osb, blkno, &suballoc_slot,
2821					     &group_blkno, &suballoc_bit);
2822	if (status < 0) {
2823		mlog(ML_ERROR, "get alloc slot and bit failed %d\n", status);
2824		goto bail;
2825	}
2826
2827	if (suballoc_slot == (u16)OCFS2_INVALID_SLOT)
2828		inode_alloc_inode = ocfs2_get_system_file_inode(osb,
2829			GLOBAL_INODE_ALLOC_SYSTEM_INODE, suballoc_slot);
2830	else
2831		inode_alloc_inode = ocfs2_get_system_file_inode(osb,
2832			INODE_ALLOC_SYSTEM_INODE, suballoc_slot);
2833	if (!inode_alloc_inode) {
2834		/* the error code could be inaccurate, but we are not able to
2835		 * get the correct one. */
2836		status = -EINVAL;
2837		mlog(ML_ERROR, "unable to get alloc inode in slot %u\n",
2838		     (u32)suballoc_slot);
2839		goto bail;
2840	}
2841
2842	inode_lock(inode_alloc_inode);
2843	status = ocfs2_inode_lock(inode_alloc_inode, &alloc_bh, 0);
2844	if (status < 0) {
2845		inode_unlock(inode_alloc_inode);
2846		iput(inode_alloc_inode);
2847		mlog(ML_ERROR, "lock on alloc inode on slot %u failed %d\n",
2848		     (u32)suballoc_slot, status);
2849		goto bail;
2850	}
2851
2852	status = ocfs2_test_suballoc_bit(osb, inode_alloc_inode, alloc_bh,
2853					 group_blkno, blkno, suballoc_bit, res);
2854	if (status < 0)
2855		mlog(ML_ERROR, "test suballoc bit failed %d\n", status);
2856
2857	ocfs2_inode_unlock(inode_alloc_inode, 0);
2858	inode_unlock(inode_alloc_inode);
2859
2860	iput(inode_alloc_inode);
2861	brelse(alloc_bh);
2862bail:
2863	if (status)
2864		mlog_errno(status);
2865	return status;
2866}
2867