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