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v5.4
   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/* -*- mode: c; c-basic-offset: 8; -*-
   3 * vim: noexpandtab sw=8 ts=8 sts=0:
   4 *
   5 * suballoc.c
   6 *
   7 * metadata alloc and free
   8 * Inspired by ext3 block groups.
   9 *
  10 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  11 */
  12
  13#include <linux/fs.h>
  14#include <linux/types.h>
  15#include <linux/slab.h>
  16#include <linux/highmem.h>
  17
  18#include <cluster/masklog.h>
  19
  20#include "ocfs2.h"
  21
  22#include "alloc.h"
  23#include "blockcheck.h"
  24#include "dlmglue.h"
  25#include "inode.h"
  26#include "journal.h"
  27#include "localalloc.h"
  28#include "suballoc.h"
  29#include "super.h"
  30#include "sysfile.h"
  31#include "uptodate.h"
  32#include "ocfs2_trace.h"
  33
  34#include "buffer_head_io.h"
  35
  36#define NOT_ALLOC_NEW_GROUP		0
  37#define ALLOC_NEW_GROUP			0x1
  38#define ALLOC_GROUPS_FROM_GLOBAL	0x2
  39
  40#define OCFS2_MAX_TO_STEAL		1024
  41
  42struct ocfs2_suballoc_result {
  43	u64		sr_bg_blkno;	/* The bg we allocated from.  Set
  44					   to 0 when a block group is
  45					   contiguous. */
  46	u64		sr_bg_stable_blkno; /*
  47					     * Doesn't change, always
  48					     * set to target block
  49					     * group descriptor
  50					     * block.
  51					     */
  52	u64		sr_blkno;	/* The first allocated block */
  53	unsigned int	sr_bit_offset;	/* The bit in the bg */
  54	unsigned int	sr_bits;	/* How many bits we claimed */
  55};
  56
  57static u64 ocfs2_group_from_res(struct ocfs2_suballoc_result *res)
  58{
  59	if (res->sr_blkno == 0)
  60		return 0;
  61
  62	if (res->sr_bg_blkno)
  63		return res->sr_bg_blkno;
  64
  65	return ocfs2_which_suballoc_group(res->sr_blkno, res->sr_bit_offset);
  66}
  67
  68static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl);
  69static int ocfs2_block_group_fill(handle_t *handle,
  70				  struct inode *alloc_inode,
  71				  struct buffer_head *bg_bh,
  72				  u64 group_blkno,
  73				  unsigned int group_clusters,
  74				  u16 my_chain,
  75				  struct ocfs2_chain_list *cl);
  76static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
  77				   struct inode *alloc_inode,
  78				   struct buffer_head *bh,
  79				   u64 max_block,
  80				   u64 *last_alloc_group,
  81				   int flags);
  82
  83static int ocfs2_cluster_group_search(struct inode *inode,
  84				      struct buffer_head *group_bh,
  85				      u32 bits_wanted, u32 min_bits,
  86				      u64 max_block,
  87				      struct ocfs2_suballoc_result *res);
  88static int ocfs2_block_group_search(struct inode *inode,
  89				    struct buffer_head *group_bh,
  90				    u32 bits_wanted, u32 min_bits,
  91				    u64 max_block,
  92				    struct ocfs2_suballoc_result *res);
  93static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
  94				     handle_t *handle,
  95				     u32 bits_wanted,
  96				     u32 min_bits,
  97				     struct ocfs2_suballoc_result *res);
  98static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
  99					 int nr);
 100static int ocfs2_relink_block_group(handle_t *handle,
 101				    struct inode *alloc_inode,
 102				    struct buffer_head *fe_bh,
 103				    struct buffer_head *bg_bh,
 104				    struct buffer_head *prev_bg_bh,
 105				    u16 chain);
 106static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
 107						     u32 wanted);
 108static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
 109						   u64 bg_blkno,
 110						   u16 bg_bit_off);
 111static inline void ocfs2_block_to_cluster_group(struct inode *inode,
 112						u64 data_blkno,
 113						u64 *bg_blkno,
 114						u16 *bg_bit_off);
 115static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
 116					     u32 bits_wanted, u64 max_block,
 117					     int flags,
 118					     struct ocfs2_alloc_context **ac);
 119
 120void ocfs2_free_ac_resource(struct ocfs2_alloc_context *ac)
 121{
 122	struct inode *inode = ac->ac_inode;
 123
 124	if (inode) {
 125		if (ac->ac_which != OCFS2_AC_USE_LOCAL)
 126			ocfs2_inode_unlock(inode, 1);
 127
 128		inode_unlock(inode);
 129
 130		iput(inode);
 131		ac->ac_inode = NULL;
 132	}
 133	brelse(ac->ac_bh);
 134	ac->ac_bh = NULL;
 135	ac->ac_resv = NULL;
 136	kfree(ac->ac_find_loc_priv);
 137	ac->ac_find_loc_priv = NULL;
 138}
 139
 140void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
 141{
 142	ocfs2_free_ac_resource(ac);
 143	kfree(ac);
 144}
 145
 146static u32 ocfs2_bits_per_group(struct ocfs2_chain_list *cl)
 147{
 148	return (u32)le16_to_cpu(cl->cl_cpg) * (u32)le16_to_cpu(cl->cl_bpc);
 149}
 150
 151#define do_error(fmt, ...)						\
 152do {									\
 153	if (resize)							\
 154		mlog(ML_ERROR, fmt, ##__VA_ARGS__);			\
 155	else								\
 156		return ocfs2_error(sb, fmt, ##__VA_ARGS__);		\
 157} while (0)
 158
 159static int ocfs2_validate_gd_self(struct super_block *sb,
 160				  struct buffer_head *bh,
 161				  int resize)
 162{
 163	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 164
 165	if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
 166		do_error("Group descriptor #%llu has bad signature %.*s\n",
 167			 (unsigned long long)bh->b_blocknr, 7,
 168			 gd->bg_signature);
 169	}
 170
 171	if (le64_to_cpu(gd->bg_blkno) != bh->b_blocknr) {
 172		do_error("Group descriptor #%llu has an invalid bg_blkno of %llu\n",
 173			 (unsigned long long)bh->b_blocknr,
 174			 (unsigned long long)le64_to_cpu(gd->bg_blkno));
 175	}
 176
 177	if (le32_to_cpu(gd->bg_generation) != OCFS2_SB(sb)->fs_generation) {
 178		do_error("Group descriptor #%llu has an invalid fs_generation of #%u\n",
 179			 (unsigned long long)bh->b_blocknr,
 180			 le32_to_cpu(gd->bg_generation));
 181	}
 182
 183	if (le16_to_cpu(gd->bg_free_bits_count) > le16_to_cpu(gd->bg_bits)) {
 184		do_error("Group descriptor #%llu has bit count %u but claims that %u are free\n",
 185			 (unsigned long long)bh->b_blocknr,
 186			 le16_to_cpu(gd->bg_bits),
 187			 le16_to_cpu(gd->bg_free_bits_count));
 188	}
 189
 190	if (le16_to_cpu(gd->bg_bits) > (8 * le16_to_cpu(gd->bg_size))) {
 191		do_error("Group descriptor #%llu has bit count %u but max bitmap bits of %u\n",
 192			 (unsigned long long)bh->b_blocknr,
 193			 le16_to_cpu(gd->bg_bits),
 194			 8 * le16_to_cpu(gd->bg_size));
 195	}
 196
 197	return 0;
 198}
 199
 200static int ocfs2_validate_gd_parent(struct super_block *sb,
 201				    struct ocfs2_dinode *di,
 202				    struct buffer_head *bh,
 203				    int resize)
 204{
 205	unsigned int max_bits;
 206	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 207
 208	if (di->i_blkno != gd->bg_parent_dinode) {
 209		do_error("Group descriptor #%llu has bad parent pointer (%llu, expected %llu)\n",
 210			 (unsigned long long)bh->b_blocknr,
 211			 (unsigned long long)le64_to_cpu(gd->bg_parent_dinode),
 212			 (unsigned long long)le64_to_cpu(di->i_blkno));
 213	}
 214
 215	max_bits = le16_to_cpu(di->id2.i_chain.cl_cpg) * le16_to_cpu(di->id2.i_chain.cl_bpc);
 216	if (le16_to_cpu(gd->bg_bits) > max_bits) {
 217		do_error("Group descriptor #%llu has bit count of %u\n",
 218			 (unsigned long long)bh->b_blocknr,
 219			 le16_to_cpu(gd->bg_bits));
 220	}
 221
 222	/* In resize, we may meet the case bg_chain == cl_next_free_rec. */
 223	if ((le16_to_cpu(gd->bg_chain) >
 224	     le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) ||
 225	    ((le16_to_cpu(gd->bg_chain) ==
 226	     le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) && !resize)) {
 227		do_error("Group descriptor #%llu has bad chain %u\n",
 228			 (unsigned long long)bh->b_blocknr,
 229			 le16_to_cpu(gd->bg_chain));
 230	}
 231
 232	return 0;
 233}
 234
 235#undef do_error
 236
 237/*
 238 * This version only prints errors.  It does not fail the filesystem, and
 239 * exists only for resize.
 240 */
 241int ocfs2_check_group_descriptor(struct super_block *sb,
 242				 struct ocfs2_dinode *di,
 243				 struct buffer_head *bh)
 244{
 245	int rc;
 246	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 247
 248	BUG_ON(!buffer_uptodate(bh));
 249
 250	/*
 251	 * If the ecc fails, we return the error but otherwise
 252	 * leave the filesystem running.  We know any error is
 253	 * local to this block.
 254	 */
 255	rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
 256	if (rc) {
 257		mlog(ML_ERROR,
 258		     "Checksum failed for group descriptor %llu\n",
 259		     (unsigned long long)bh->b_blocknr);
 260	} else
 261		rc = ocfs2_validate_gd_self(sb, bh, 1);
 262	if (!rc)
 263		rc = ocfs2_validate_gd_parent(sb, di, bh, 1);
 264
 265	return rc;
 266}
 267
 268static int ocfs2_validate_group_descriptor(struct super_block *sb,
 269					   struct buffer_head *bh)
 270{
 271	int rc;
 272	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 273
 274	trace_ocfs2_validate_group_descriptor(
 275					(unsigned long long)bh->b_blocknr);
 276
 277	BUG_ON(!buffer_uptodate(bh));
 278
 279	/*
 280	 * If the ecc fails, we return the error but otherwise
 281	 * leave the filesystem running.  We know any error is
 282	 * local to this block.
 283	 */
 284	rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
 285	if (rc)
 286		return rc;
 287
 288	/*
 289	 * Errors after here are fatal.
 290	 */
 291
 292	return ocfs2_validate_gd_self(sb, bh, 0);
 293}
 294
 295int ocfs2_read_group_descriptor(struct inode *inode, struct ocfs2_dinode *di,
 296				u64 gd_blkno, struct buffer_head **bh)
 297{
 298	int rc;
 299	struct buffer_head *tmp = *bh;
 300
 301	rc = ocfs2_read_block(INODE_CACHE(inode), gd_blkno, &tmp,
 302			      ocfs2_validate_group_descriptor);
 303	if (rc)
 304		goto out;
 305
 306	rc = ocfs2_validate_gd_parent(inode->i_sb, di, tmp, 0);
 307	if (rc) {
 308		brelse(tmp);
 309		goto out;
 310	}
 311
 312	/* If ocfs2_read_block() got us a new bh, pass it up. */
 313	if (!*bh)
 314		*bh = tmp;
 315
 316out:
 317	return rc;
 318}
 319
 320static void ocfs2_bg_discontig_add_extent(struct ocfs2_super *osb,
 321					  struct ocfs2_group_desc *bg,
 322					  struct ocfs2_chain_list *cl,
 323					  u64 p_blkno, unsigned int clusters)
 324{
 325	struct ocfs2_extent_list *el = &bg->bg_list;
 326	struct ocfs2_extent_rec *rec;
 327
 328	BUG_ON(!ocfs2_supports_discontig_bg(osb));
 329	if (!el->l_next_free_rec)
 330		el->l_count = cpu_to_le16(ocfs2_extent_recs_per_gd(osb->sb));
 331	rec = &el->l_recs[le16_to_cpu(el->l_next_free_rec)];
 332	rec->e_blkno = cpu_to_le64(p_blkno);
 333	rec->e_cpos = cpu_to_le32(le16_to_cpu(bg->bg_bits) /
 334				  le16_to_cpu(cl->cl_bpc));
 335	rec->e_leaf_clusters = cpu_to_le16(clusters);
 336	le16_add_cpu(&bg->bg_bits, clusters * le16_to_cpu(cl->cl_bpc));
 337	le16_add_cpu(&bg->bg_free_bits_count,
 338		     clusters * le16_to_cpu(cl->cl_bpc));
 339	le16_add_cpu(&el->l_next_free_rec, 1);
 340}
 341
 342static int ocfs2_block_group_fill(handle_t *handle,
 343				  struct inode *alloc_inode,
 344				  struct buffer_head *bg_bh,
 345				  u64 group_blkno,
 346				  unsigned int group_clusters,
 347				  u16 my_chain,
 348				  struct ocfs2_chain_list *cl)
 349{
 350	int status = 0;
 351	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 352	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 353	struct super_block * sb = alloc_inode->i_sb;
 354
 355	if (((unsigned long long) bg_bh->b_blocknr) != group_blkno) {
 356		status = ocfs2_error(alloc_inode->i_sb,
 357				     "group block (%llu) != b_blocknr (%llu)\n",
 358				     (unsigned long long)group_blkno,
 359				     (unsigned long long) bg_bh->b_blocknr);
 360		goto bail;
 361	}
 362
 363	status = ocfs2_journal_access_gd(handle,
 364					 INODE_CACHE(alloc_inode),
 365					 bg_bh,
 366					 OCFS2_JOURNAL_ACCESS_CREATE);
 367	if (status < 0) {
 368		mlog_errno(status);
 369		goto bail;
 370	}
 371
 372	memset(bg, 0, sb->s_blocksize);
 373	strcpy(bg->bg_signature, OCFS2_GROUP_DESC_SIGNATURE);
 374	bg->bg_generation = cpu_to_le32(osb->fs_generation);
 375	bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb, 1,
 376						osb->s_feature_incompat));
 377	bg->bg_chain = cpu_to_le16(my_chain);
 378	bg->bg_next_group = cl->cl_recs[my_chain].c_blkno;
 379	bg->bg_parent_dinode = cpu_to_le64(OCFS2_I(alloc_inode)->ip_blkno);
 380	bg->bg_blkno = cpu_to_le64(group_blkno);
 381	if (group_clusters == le16_to_cpu(cl->cl_cpg))
 382		bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
 383	else
 384		ocfs2_bg_discontig_add_extent(osb, bg, cl, group_blkno,
 385					      group_clusters);
 386
 387	/* set the 1st bit in the bitmap to account for the descriptor block */
 388	ocfs2_set_bit(0, (unsigned long *)bg->bg_bitmap);
 389	bg->bg_free_bits_count = cpu_to_le16(le16_to_cpu(bg->bg_bits) - 1);
 390
 391	ocfs2_journal_dirty(handle, bg_bh);
 392
 393	/* There is no need to zero out or otherwise initialize the
 394	 * other blocks in a group - All valid FS metadata in a block
 395	 * group stores the superblock fs_generation value at
 396	 * allocation time. */
 397
 398bail:
 399	if (status)
 400		mlog_errno(status);
 401	return status;
 402}
 403
 404static inline u16 ocfs2_find_smallest_chain(struct ocfs2_chain_list *cl)
 405{
 406	u16 curr, best;
 407
 408	best = curr = 0;
 409	while (curr < le16_to_cpu(cl->cl_count)) {
 410		if (le32_to_cpu(cl->cl_recs[best].c_total) >
 411		    le32_to_cpu(cl->cl_recs[curr].c_total))
 412			best = curr;
 413		curr++;
 414	}
 415	return best;
 416}
 417
 418static struct buffer_head *
 419ocfs2_block_group_alloc_contig(struct ocfs2_super *osb, handle_t *handle,
 420			       struct inode *alloc_inode,
 421			       struct ocfs2_alloc_context *ac,
 422			       struct ocfs2_chain_list *cl)
 423{
 424	int status;
 425	u32 bit_off, num_bits;
 426	u64 bg_blkno;
 427	struct buffer_head *bg_bh;
 428	unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
 429
 430	status = ocfs2_claim_clusters(handle, ac,
 431				      le16_to_cpu(cl->cl_cpg), &bit_off,
 432				      &num_bits);
 433	if (status < 0) {
 434		if (status != -ENOSPC)
 435			mlog_errno(status);
 436		goto bail;
 437	}
 438
 439	/* setup the group */
 440	bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 441	trace_ocfs2_block_group_alloc_contig(
 442	     (unsigned long long)bg_blkno, alloc_rec);
 443
 444	bg_bh = sb_getblk(osb->sb, bg_blkno);
 445	if (!bg_bh) {
 446		status = -ENOMEM;
 447		mlog_errno(status);
 448		goto bail;
 449	}
 450	ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
 451
 452	status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
 453					bg_blkno, num_bits, alloc_rec, cl);
 454	if (status < 0) {
 455		brelse(bg_bh);
 456		mlog_errno(status);
 457	}
 458
 459bail:
 460	return status ? ERR_PTR(status) : bg_bh;
 461}
 462
 463static int ocfs2_block_group_claim_bits(struct ocfs2_super *osb,
 464					handle_t *handle,
 465					struct ocfs2_alloc_context *ac,
 466					unsigned int min_bits,
 467					u32 *bit_off, u32 *num_bits)
 468{
 469	int status = 0;
 470
 471	while (min_bits) {
 472		status = ocfs2_claim_clusters(handle, ac, min_bits,
 473					      bit_off, num_bits);
 474		if (status != -ENOSPC)
 475			break;
 476
 477		min_bits >>= 1;
 478	}
 479
 480	return status;
 481}
 482
 483static int ocfs2_block_group_grow_discontig(handle_t *handle,
 484					    struct inode *alloc_inode,
 485					    struct buffer_head *bg_bh,
 486					    struct ocfs2_alloc_context *ac,
 487					    struct ocfs2_chain_list *cl,
 488					    unsigned int min_bits)
 489{
 490	int status;
 491	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 492	struct ocfs2_group_desc *bg =
 493		(struct ocfs2_group_desc *)bg_bh->b_data;
 494	unsigned int needed = le16_to_cpu(cl->cl_cpg) -
 495			 le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
 496	u32 p_cpos, clusters;
 497	u64 p_blkno;
 498	struct ocfs2_extent_list *el = &bg->bg_list;
 499
 500	status = ocfs2_journal_access_gd(handle,
 501					 INODE_CACHE(alloc_inode),
 502					 bg_bh,
 503					 OCFS2_JOURNAL_ACCESS_CREATE);
 504	if (status < 0) {
 505		mlog_errno(status);
 506		goto bail;
 507	}
 508
 509	while ((needed > 0) && (le16_to_cpu(el->l_next_free_rec) <
 510				le16_to_cpu(el->l_count))) {
 511		if (min_bits > needed)
 512			min_bits = needed;
 513		status = ocfs2_block_group_claim_bits(osb, handle, ac,
 514						      min_bits, &p_cpos,
 515						      &clusters);
 516		if (status < 0) {
 517			if (status != -ENOSPC)
 518				mlog_errno(status);
 519			goto bail;
 520		}
 521		p_blkno = ocfs2_clusters_to_blocks(osb->sb, p_cpos);
 522		ocfs2_bg_discontig_add_extent(osb, bg, cl, p_blkno,
 523					      clusters);
 524
 525		min_bits = clusters;
 526		needed = le16_to_cpu(cl->cl_cpg) -
 527			 le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
 528	}
 529
 530	if (needed > 0) {
 531		/*
 532		 * We have used up all the extent rec but can't fill up
 533		 * the cpg. So bail out.
 534		 */
 535		status = -ENOSPC;
 536		goto bail;
 537	}
 538
 539	ocfs2_journal_dirty(handle, bg_bh);
 540
 541bail:
 542	return status;
 543}
 544
 545static void ocfs2_bg_alloc_cleanup(handle_t *handle,
 546				   struct ocfs2_alloc_context *cluster_ac,
 547				   struct inode *alloc_inode,
 548				   struct buffer_head *bg_bh)
 549{
 550	int i, ret;
 551	struct ocfs2_group_desc *bg;
 552	struct ocfs2_extent_list *el;
 553	struct ocfs2_extent_rec *rec;
 554
 555	if (!bg_bh)
 556		return;
 557
 558	bg = (struct ocfs2_group_desc *)bg_bh->b_data;
 559	el = &bg->bg_list;
 560	for (i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
 561		rec = &el->l_recs[i];
 562		ret = ocfs2_free_clusters(handle, cluster_ac->ac_inode,
 563					  cluster_ac->ac_bh,
 564					  le64_to_cpu(rec->e_blkno),
 565					  le16_to_cpu(rec->e_leaf_clusters));
 566		if (ret)
 567			mlog_errno(ret);
 568		/* Try all the clusters to free */
 569	}
 570
 571	ocfs2_remove_from_cache(INODE_CACHE(alloc_inode), bg_bh);
 572	brelse(bg_bh);
 573}
 574
 575static struct buffer_head *
 576ocfs2_block_group_alloc_discontig(handle_t *handle,
 577				  struct inode *alloc_inode,
 578				  struct ocfs2_alloc_context *ac,
 579				  struct ocfs2_chain_list *cl)
 580{
 581	int status;
 582	u32 bit_off, num_bits;
 583	u64 bg_blkno;
 584	unsigned int min_bits = le16_to_cpu(cl->cl_cpg) >> 1;
 585	struct buffer_head *bg_bh = NULL;
 586	unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
 587	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 588
 589	if (!ocfs2_supports_discontig_bg(osb)) {
 590		status = -ENOSPC;
 591		goto bail;
 592	}
 593
 594	status = ocfs2_extend_trans(handle,
 595				    ocfs2_calc_bg_discontig_credits(osb->sb));
 596	if (status) {
 597		mlog_errno(status);
 598		goto bail;
 599	}
 600
 601	/*
 602	 * We're going to be grabbing from multiple cluster groups.
 603	 * We don't have enough credits to relink them all, and the
 604	 * cluster groups will be staying in cache for the duration of
 605	 * this operation.
 606	 */
 607	ac->ac_disable_chain_relink = 1;
 608
 609	/* Claim the first region */
 610	status = ocfs2_block_group_claim_bits(osb, handle, ac, min_bits,
 611					      &bit_off, &num_bits);
 612	if (status < 0) {
 613		if (status != -ENOSPC)
 614			mlog_errno(status);
 615		goto bail;
 616	}
 617	min_bits = num_bits;
 618
 619	/* setup the group */
 620	bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 621	trace_ocfs2_block_group_alloc_discontig(
 622				(unsigned long long)bg_blkno, alloc_rec);
 623
 624	bg_bh = sb_getblk(osb->sb, bg_blkno);
 625	if (!bg_bh) {
 626		status = -ENOMEM;
 627		mlog_errno(status);
 628		goto bail;
 629	}
 630	ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
 631
 632	status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
 633					bg_blkno, num_bits, alloc_rec, cl);
 634	if (status < 0) {
 635		mlog_errno(status);
 636		goto bail;
 637	}
 638
 639	status = ocfs2_block_group_grow_discontig(handle, alloc_inode,
 640						  bg_bh, ac, cl, min_bits);
 641	if (status)
 642		mlog_errno(status);
 643
 644bail:
 645	if (status)
 646		ocfs2_bg_alloc_cleanup(handle, ac, alloc_inode, bg_bh);
 647	return status ? ERR_PTR(status) : bg_bh;
 648}
 649
 650/*
 651 * We expect the block group allocator to already be locked.
 652 */
 653static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
 654				   struct inode *alloc_inode,
 655				   struct buffer_head *bh,
 656				   u64 max_block,
 657				   u64 *last_alloc_group,
 658				   int flags)
 659{
 660	int status, credits;
 661	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) bh->b_data;
 662	struct ocfs2_chain_list *cl;
 663	struct ocfs2_alloc_context *ac = NULL;
 664	handle_t *handle = NULL;
 665	u16 alloc_rec;
 666	struct buffer_head *bg_bh = NULL;
 667	struct ocfs2_group_desc *bg;
 668
 669	BUG_ON(ocfs2_is_cluster_bitmap(alloc_inode));
 670
 671	cl = &fe->id2.i_chain;
 672	status = ocfs2_reserve_clusters_with_limit(osb,
 673						   le16_to_cpu(cl->cl_cpg),
 674						   max_block, flags, &ac);
 675	if (status < 0) {
 676		if (status != -ENOSPC)
 677			mlog_errno(status);
 678		goto bail;
 679	}
 680
 681	credits = ocfs2_calc_group_alloc_credits(osb->sb,
 682						 le16_to_cpu(cl->cl_cpg));
 683	handle = ocfs2_start_trans(osb, credits);
 684	if (IS_ERR(handle)) {
 685		status = PTR_ERR(handle);
 686		handle = NULL;
 687		mlog_errno(status);
 688		goto bail;
 689	}
 690
 691	if (last_alloc_group && *last_alloc_group != 0) {
 692		trace_ocfs2_block_group_alloc(
 693				(unsigned long long)*last_alloc_group);
 694		ac->ac_last_group = *last_alloc_group;
 695	}
 696
 697	bg_bh = ocfs2_block_group_alloc_contig(osb, handle, alloc_inode,
 698					       ac, cl);
 699	if (IS_ERR(bg_bh) && (PTR_ERR(bg_bh) == -ENOSPC))
 700		bg_bh = ocfs2_block_group_alloc_discontig(handle,
 701							  alloc_inode,
 702							  ac, cl);
 703	if (IS_ERR(bg_bh)) {
 704		status = PTR_ERR(bg_bh);
 705		bg_bh = NULL;
 706		if (status != -ENOSPC)
 707			mlog_errno(status);
 708		goto bail;
 709	}
 710	bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 711
 712	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
 713					 bh, OCFS2_JOURNAL_ACCESS_WRITE);
 714	if (status < 0) {
 715		mlog_errno(status);
 716		goto bail;
 717	}
 718
 719	alloc_rec = le16_to_cpu(bg->bg_chain);
 720	le32_add_cpu(&cl->cl_recs[alloc_rec].c_free,
 721		     le16_to_cpu(bg->bg_free_bits_count));
 722	le32_add_cpu(&cl->cl_recs[alloc_rec].c_total,
 723		     le16_to_cpu(bg->bg_bits));
 724	cl->cl_recs[alloc_rec].c_blkno = bg->bg_blkno;
 725	if (le16_to_cpu(cl->cl_next_free_rec) < le16_to_cpu(cl->cl_count))
 726		le16_add_cpu(&cl->cl_next_free_rec, 1);
 727
 728	le32_add_cpu(&fe->id1.bitmap1.i_used, le16_to_cpu(bg->bg_bits) -
 729					le16_to_cpu(bg->bg_free_bits_count));
 730	le32_add_cpu(&fe->id1.bitmap1.i_total, le16_to_cpu(bg->bg_bits));
 731	le32_add_cpu(&fe->i_clusters, le16_to_cpu(cl->cl_cpg));
 732
 733	ocfs2_journal_dirty(handle, bh);
 734
 735	spin_lock(&OCFS2_I(alloc_inode)->ip_lock);
 736	OCFS2_I(alloc_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
 737	fe->i_size = cpu_to_le64(ocfs2_clusters_to_bytes(alloc_inode->i_sb,
 738					     le32_to_cpu(fe->i_clusters)));
 739	spin_unlock(&OCFS2_I(alloc_inode)->ip_lock);
 740	i_size_write(alloc_inode, le64_to_cpu(fe->i_size));
 741	alloc_inode->i_blocks = ocfs2_inode_sector_count(alloc_inode);
 742	ocfs2_update_inode_fsync_trans(handle, alloc_inode, 0);
 743
 744	status = 0;
 745
 746	/* save the new last alloc group so that the caller can cache it. */
 747	if (last_alloc_group)
 748		*last_alloc_group = ac->ac_last_group;
 749
 750bail:
 751	if (handle)
 752		ocfs2_commit_trans(osb, handle);
 753
 754	if (ac)
 755		ocfs2_free_alloc_context(ac);
 756
 757	brelse(bg_bh);
 758
 759	if (status)
 760		mlog_errno(status);
 761	return status;
 762}
 763
 764static int ocfs2_reserve_suballoc_bits(struct ocfs2_super *osb,
 765				       struct ocfs2_alloc_context *ac,
 766				       int type,
 767				       u32 slot,
 768				       u64 *last_alloc_group,
 769				       int flags)
 770{
 771	int status;
 772	u32 bits_wanted = ac->ac_bits_wanted;
 773	struct inode *alloc_inode;
 774	struct buffer_head *bh = NULL;
 775	struct ocfs2_dinode *fe;
 776	u32 free_bits;
 777
 778	alloc_inode = ocfs2_get_system_file_inode(osb, type, slot);
 779	if (!alloc_inode) {
 780		mlog_errno(-EINVAL);
 781		return -EINVAL;
 782	}
 783
 784	inode_lock(alloc_inode);
 785
 786	status = ocfs2_inode_lock(alloc_inode, &bh, 1);
 787	if (status < 0) {
 788		inode_unlock(alloc_inode);
 789		iput(alloc_inode);
 790
 791		mlog_errno(status);
 792		return status;
 793	}
 794
 795	ac->ac_inode = alloc_inode;
 796	ac->ac_alloc_slot = slot;
 797
 798	fe = (struct ocfs2_dinode *) bh->b_data;
 799
 800	/* The bh was validated by the inode read inside
 801	 * ocfs2_inode_lock().  Any corruption is a code bug. */
 802	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
 803
 804	if (!(fe->i_flags & cpu_to_le32(OCFS2_CHAIN_FL))) {
 805		status = ocfs2_error(alloc_inode->i_sb,
 806				     "Invalid chain allocator %llu\n",
 807				     (unsigned long long)le64_to_cpu(fe->i_blkno));
 808		goto bail;
 809	}
 810
 811	free_bits = le32_to_cpu(fe->id1.bitmap1.i_total) -
 812		le32_to_cpu(fe->id1.bitmap1.i_used);
 813
 814	if (bits_wanted > free_bits) {
 815		/* cluster bitmap never grows */
 816		if (ocfs2_is_cluster_bitmap(alloc_inode)) {
 817			trace_ocfs2_reserve_suballoc_bits_nospc(bits_wanted,
 818								free_bits);
 819			status = -ENOSPC;
 820			goto bail;
 821		}
 822
 823		if (!(flags & ALLOC_NEW_GROUP)) {
 824			trace_ocfs2_reserve_suballoc_bits_no_new_group(
 825						slot, bits_wanted, free_bits);
 826			status = -ENOSPC;
 827			goto bail;
 828		}
 829
 830		status = ocfs2_block_group_alloc(osb, alloc_inode, bh,
 831						 ac->ac_max_block,
 832						 last_alloc_group, flags);
 833		if (status < 0) {
 834			if (status != -ENOSPC)
 835				mlog_errno(status);
 836			goto bail;
 837		}
 838		atomic_inc(&osb->alloc_stats.bg_extends);
 839
 840		/* You should never ask for this much metadata */
 841		BUG_ON(bits_wanted >
 842		       (le32_to_cpu(fe->id1.bitmap1.i_total)
 843			- le32_to_cpu(fe->id1.bitmap1.i_used)));
 844	}
 845
 846	get_bh(bh);
 847	ac->ac_bh = bh;
 848bail:
 849	brelse(bh);
 850
 851	if (status)
 852		mlog_errno(status);
 853	return status;
 854}
 855
 856static void ocfs2_init_inode_steal_slot(struct ocfs2_super *osb)
 857{
 858	spin_lock(&osb->osb_lock);
 859	osb->s_inode_steal_slot = OCFS2_INVALID_SLOT;
 860	spin_unlock(&osb->osb_lock);
 861	atomic_set(&osb->s_num_inodes_stolen, 0);
 862}
 863
 864static void ocfs2_init_meta_steal_slot(struct ocfs2_super *osb)
 865{
 866	spin_lock(&osb->osb_lock);
 867	osb->s_meta_steal_slot = OCFS2_INVALID_SLOT;
 868	spin_unlock(&osb->osb_lock);
 869	atomic_set(&osb->s_num_meta_stolen, 0);
 870}
 871
 872void ocfs2_init_steal_slots(struct ocfs2_super *osb)
 873{
 874	ocfs2_init_inode_steal_slot(osb);
 875	ocfs2_init_meta_steal_slot(osb);
 876}
 877
 878static void __ocfs2_set_steal_slot(struct ocfs2_super *osb, int slot, int type)
 879{
 880	spin_lock(&osb->osb_lock);
 881	if (type == INODE_ALLOC_SYSTEM_INODE)
 882		osb->s_inode_steal_slot = slot;
 883	else if (type == EXTENT_ALLOC_SYSTEM_INODE)
 884		osb->s_meta_steal_slot = slot;
 885	spin_unlock(&osb->osb_lock);
 886}
 887
 888static int __ocfs2_get_steal_slot(struct ocfs2_super *osb, int type)
 889{
 890	int slot = OCFS2_INVALID_SLOT;
 891
 892	spin_lock(&osb->osb_lock);
 893	if (type == INODE_ALLOC_SYSTEM_INODE)
 894		slot = osb->s_inode_steal_slot;
 895	else if (type == EXTENT_ALLOC_SYSTEM_INODE)
 896		slot = osb->s_meta_steal_slot;
 897	spin_unlock(&osb->osb_lock);
 898
 899	return slot;
 900}
 901
 902static int ocfs2_get_inode_steal_slot(struct ocfs2_super *osb)
 903{
 904	return __ocfs2_get_steal_slot(osb, INODE_ALLOC_SYSTEM_INODE);
 905}
 906
 907static int ocfs2_get_meta_steal_slot(struct ocfs2_super *osb)
 908{
 909	return __ocfs2_get_steal_slot(osb, EXTENT_ALLOC_SYSTEM_INODE);
 910}
 911
 912static int ocfs2_steal_resource(struct ocfs2_super *osb,
 913				struct ocfs2_alloc_context *ac,
 914				int type)
 915{
 916	int i, status = -ENOSPC;
 917	int slot = __ocfs2_get_steal_slot(osb, type);
 918
 919	/* Start to steal resource from the first slot after ours. */
 920	if (slot == OCFS2_INVALID_SLOT)
 921		slot = osb->slot_num + 1;
 922
 923	for (i = 0; i < osb->max_slots; i++, slot++) {
 924		if (slot == osb->max_slots)
 925			slot = 0;
 926
 927		if (slot == osb->slot_num)
 928			continue;
 929
 930		status = ocfs2_reserve_suballoc_bits(osb, ac,
 931						     type,
 932						     (u32)slot, NULL,
 933						     NOT_ALLOC_NEW_GROUP);
 934		if (status >= 0) {
 935			__ocfs2_set_steal_slot(osb, slot, type);
 936			break;
 937		}
 938
 939		ocfs2_free_ac_resource(ac);
 940	}
 941
 942	return status;
 943}
 944
 945static int ocfs2_steal_inode(struct ocfs2_super *osb,
 946			     struct ocfs2_alloc_context *ac)
 947{
 948	return ocfs2_steal_resource(osb, ac, INODE_ALLOC_SYSTEM_INODE);
 949}
 950
 951static int ocfs2_steal_meta(struct ocfs2_super *osb,
 952			    struct ocfs2_alloc_context *ac)
 953{
 954	return ocfs2_steal_resource(osb, ac, EXTENT_ALLOC_SYSTEM_INODE);
 955}
 956
 957int ocfs2_reserve_new_metadata_blocks(struct ocfs2_super *osb,
 958				      int blocks,
 959				      struct ocfs2_alloc_context **ac)
 960{
 961	int status;
 962	int slot = ocfs2_get_meta_steal_slot(osb);
 963
 964	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 965	if (!(*ac)) {
 966		status = -ENOMEM;
 967		mlog_errno(status);
 968		goto bail;
 969	}
 970
 971	(*ac)->ac_bits_wanted = blocks;
 972	(*ac)->ac_which = OCFS2_AC_USE_META;
 973	(*ac)->ac_group_search = ocfs2_block_group_search;
 974
 975	if (slot != OCFS2_INVALID_SLOT &&
 976		atomic_read(&osb->s_num_meta_stolen) < OCFS2_MAX_TO_STEAL)
 977		goto extent_steal;
 978
 979	atomic_set(&osb->s_num_meta_stolen, 0);
 980	status = ocfs2_reserve_suballoc_bits(osb, (*ac),
 981					     EXTENT_ALLOC_SYSTEM_INODE,
 982					     (u32)osb->slot_num, NULL,
 983					     ALLOC_GROUPS_FROM_GLOBAL|ALLOC_NEW_GROUP);
 984
 985
 986	if (status >= 0) {
 987		status = 0;
 988		if (slot != OCFS2_INVALID_SLOT)
 989			ocfs2_init_meta_steal_slot(osb);
 990		goto bail;
 991	} else if (status < 0 && status != -ENOSPC) {
 992		mlog_errno(status);
 993		goto bail;
 994	}
 995
 996	ocfs2_free_ac_resource(*ac);
 997
 998extent_steal:
 999	status = ocfs2_steal_meta(osb, *ac);
1000	atomic_inc(&osb->s_num_meta_stolen);
1001	if (status < 0) {
1002		if (status != -ENOSPC)
1003			mlog_errno(status);
1004		goto bail;
1005	}
1006
1007	status = 0;
1008bail:
1009	if ((status < 0) && *ac) {
1010		ocfs2_free_alloc_context(*ac);
1011		*ac = NULL;
1012	}
1013
1014	if (status)
1015		mlog_errno(status);
1016	return status;
1017}
1018
1019int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
1020			       struct ocfs2_extent_list *root_el,
1021			       struct ocfs2_alloc_context **ac)
1022{
1023	return ocfs2_reserve_new_metadata_blocks(osb,
1024					ocfs2_extend_meta_needed(root_el),
1025					ac);
1026}
1027
1028int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
1029			    struct ocfs2_alloc_context **ac)
1030{
1031	int status;
1032	int slot = ocfs2_get_inode_steal_slot(osb);
1033	u64 alloc_group;
1034
1035	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1036	if (!(*ac)) {
1037		status = -ENOMEM;
1038		mlog_errno(status);
1039		goto bail;
1040	}
1041
1042	(*ac)->ac_bits_wanted = 1;
1043	(*ac)->ac_which = OCFS2_AC_USE_INODE;
1044
1045	(*ac)->ac_group_search = ocfs2_block_group_search;
1046
1047	/*
1048	 * stat(2) can't handle i_ino > 32bits, so we tell the
1049	 * lower levels not to allocate us a block group past that
1050	 * limit.  The 'inode64' mount option avoids this behavior.
1051	 */
1052	if (!(osb->s_mount_opt & OCFS2_MOUNT_INODE64))
1053		(*ac)->ac_max_block = (u32)~0U;
1054
1055	/*
1056	 * slot is set when we successfully steal inode from other nodes.
1057	 * It is reset in 3 places:
1058	 * 1. when we flush the truncate log
1059	 * 2. when we complete local alloc recovery.
1060	 * 3. when we successfully allocate from our own slot.
1061	 * After it is set, we will go on stealing inodes until we find the
1062	 * need to check our slots to see whether there is some space for us.
1063	 */
1064	if (slot != OCFS2_INVALID_SLOT &&
1065	    atomic_read(&osb->s_num_inodes_stolen) < OCFS2_MAX_TO_STEAL)
1066		goto inode_steal;
1067
1068	atomic_set(&osb->s_num_inodes_stolen, 0);
1069	alloc_group = osb->osb_inode_alloc_group;
1070	status = ocfs2_reserve_suballoc_bits(osb, *ac,
1071					     INODE_ALLOC_SYSTEM_INODE,
1072					     (u32)osb->slot_num,
1073					     &alloc_group,
1074					     ALLOC_NEW_GROUP |
1075					     ALLOC_GROUPS_FROM_GLOBAL);
1076	if (status >= 0) {
1077		status = 0;
1078
1079		spin_lock(&osb->osb_lock);
1080		osb->osb_inode_alloc_group = alloc_group;
1081		spin_unlock(&osb->osb_lock);
1082		trace_ocfs2_reserve_new_inode_new_group(
1083			(unsigned long long)alloc_group);
1084
1085		/*
1086		 * Some inodes must be freed by us, so try to allocate
1087		 * from our own next time.
1088		 */
1089		if (slot != OCFS2_INVALID_SLOT)
1090			ocfs2_init_inode_steal_slot(osb);
1091		goto bail;
1092	} else if (status < 0 && status != -ENOSPC) {
1093		mlog_errno(status);
1094		goto bail;
1095	}
1096
1097	ocfs2_free_ac_resource(*ac);
1098
1099inode_steal:
1100	status = ocfs2_steal_inode(osb, *ac);
1101	atomic_inc(&osb->s_num_inodes_stolen);
1102	if (status < 0) {
1103		if (status != -ENOSPC)
1104			mlog_errno(status);
1105		goto bail;
1106	}
1107
1108	status = 0;
1109bail:
1110	if ((status < 0) && *ac) {
1111		ocfs2_free_alloc_context(*ac);
1112		*ac = NULL;
1113	}
1114
1115	if (status)
1116		mlog_errno(status);
1117	return status;
1118}
1119
1120/* local alloc code has to do the same thing, so rather than do this
1121 * twice.. */
1122int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
1123				      struct ocfs2_alloc_context *ac)
1124{
1125	int status;
1126
1127	ac->ac_which = OCFS2_AC_USE_MAIN;
1128	ac->ac_group_search = ocfs2_cluster_group_search;
1129
1130	status = ocfs2_reserve_suballoc_bits(osb, ac,
1131					     GLOBAL_BITMAP_SYSTEM_INODE,
1132					     OCFS2_INVALID_SLOT, NULL,
1133					     ALLOC_NEW_GROUP);
1134	if (status < 0 && status != -ENOSPC)
1135		mlog_errno(status);
1136
1137	return status;
1138}
1139
1140/* Callers don't need to care which bitmap (local alloc or main) to
1141 * use so we figure it out for them, but unfortunately this clutters
1142 * things a bit. */
1143static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
1144					     u32 bits_wanted, u64 max_block,
1145					     int flags,
1146					     struct ocfs2_alloc_context **ac)
1147{
1148	int status, ret = 0;
1149	int retried = 0;
1150
1151	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1152	if (!(*ac)) {
1153		status = -ENOMEM;
1154		mlog_errno(status);
1155		goto bail;
1156	}
1157
1158	(*ac)->ac_bits_wanted = bits_wanted;
1159	(*ac)->ac_max_block = max_block;
1160
1161	status = -ENOSPC;
1162	if (!(flags & ALLOC_GROUPS_FROM_GLOBAL) &&
1163	    ocfs2_alloc_should_use_local(osb, bits_wanted)) {
1164		status = ocfs2_reserve_local_alloc_bits(osb,
1165							bits_wanted,
1166							*ac);
1167		if ((status < 0) && (status != -ENOSPC)) {
1168			mlog_errno(status);
1169			goto bail;
1170		}
1171	}
1172
1173	if (status == -ENOSPC) {
1174retry:
1175		status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
1176		/* Retry if there is sufficient space cached in truncate log */
1177		if (status == -ENOSPC && !retried) {
1178			retried = 1;
1179			ocfs2_inode_unlock((*ac)->ac_inode, 1);
1180			inode_unlock((*ac)->ac_inode);
1181
1182			ret = ocfs2_try_to_free_truncate_log(osb, bits_wanted);
1183			if (ret == 1) {
1184				iput((*ac)->ac_inode);
1185				(*ac)->ac_inode = NULL;
1186				goto retry;
1187			}
1188
1189			if (ret < 0)
1190				mlog_errno(ret);
1191
1192			inode_lock((*ac)->ac_inode);
1193			ret = ocfs2_inode_lock((*ac)->ac_inode, NULL, 1);
1194			if (ret < 0) {
1195				mlog_errno(ret);
1196				inode_unlock((*ac)->ac_inode);
1197				iput((*ac)->ac_inode);
1198				(*ac)->ac_inode = NULL;
1199				goto bail;
1200			}
1201		}
1202		if (status < 0) {
1203			if (status != -ENOSPC)
1204				mlog_errno(status);
1205			goto bail;
1206		}
1207	}
1208
1209	status = 0;
1210bail:
1211	if ((status < 0) && *ac) {
1212		ocfs2_free_alloc_context(*ac);
1213		*ac = NULL;
1214	}
1215
1216	if (status)
1217		mlog_errno(status);
1218	return status;
1219}
1220
1221int ocfs2_reserve_clusters(struct ocfs2_super *osb,
1222			   u32 bits_wanted,
1223			   struct ocfs2_alloc_context **ac)
1224{
1225	return ocfs2_reserve_clusters_with_limit(osb, bits_wanted, 0,
1226						 ALLOC_NEW_GROUP, ac);
1227}
1228
1229/*
1230 * More or less lifted from ext3. I'll leave their description below:
1231 *
1232 * "For ext3 allocations, we must not reuse any blocks which are
1233 * allocated in the bitmap buffer's "last committed data" copy.  This
1234 * prevents deletes from freeing up the page for reuse until we have
1235 * committed the delete transaction.
1236 *
1237 * If we didn't do this, then deleting something and reallocating it as
1238 * data would allow the old block to be overwritten before the
1239 * transaction committed (because we force data to disk before commit).
1240 * This would lead to corruption if we crashed between overwriting the
1241 * data and committing the delete.
1242 *
1243 * @@@ We may want to make this allocation behaviour conditional on
1244 * data-writes at some point, and disable it for metadata allocations or
1245 * sync-data inodes."
1246 *
1247 * Note: OCFS2 already does this differently for metadata vs data
1248 * allocations, as those bitmaps are separate and undo access is never
1249 * called on a metadata group descriptor.
1250 */
1251static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
1252					 int nr)
1253{
1254	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1255	int ret;
1256
1257	if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
1258		return 0;
1259
1260	if (!buffer_jbd(bg_bh))
1261		return 1;
1262
1263	jbd_lock_bh_state(bg_bh);
1264	bg = (struct ocfs2_group_desc *) bh2jh(bg_bh)->b_committed_data;
1265	if (bg)
1266		ret = !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
1267	else
1268		ret = 1;
1269	jbd_unlock_bh_state(bg_bh);
1270
1271	return ret;
1272}
1273
1274static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
1275					     struct buffer_head *bg_bh,
1276					     unsigned int bits_wanted,
1277					     unsigned int total_bits,
1278					     struct ocfs2_suballoc_result *res)
1279{
1280	void *bitmap;
1281	u16 best_offset, best_size;
1282	int offset, start, found, status = 0;
1283	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1284
1285	/* Callers got this descriptor from
1286	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1287	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1288
1289	found = start = best_offset = best_size = 0;
1290	bitmap = bg->bg_bitmap;
1291
1292	while((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) != -1) {
1293		if (offset == total_bits)
1294			break;
1295
1296		if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
1297			/* We found a zero, but we can't use it as it
1298			 * hasn't been put to disk yet! */
1299			found = 0;
1300			start = offset + 1;
1301		} else if (offset == start) {
1302			/* we found a zero */
1303			found++;
1304			/* move start to the next bit to test */
1305			start++;
1306		} else {
1307			/* got a zero after some ones */
1308			found = 1;
1309			start = offset + 1;
1310		}
1311		if (found > best_size) {
1312			best_size = found;
1313			best_offset = start - found;
1314		}
1315		/* we got everything we needed */
1316		if (found == bits_wanted) {
1317			/* mlog(0, "Found it all!\n"); */
1318			break;
1319		}
1320	}
1321
1322	if (best_size) {
1323		res->sr_bit_offset = best_offset;
1324		res->sr_bits = best_size;
1325	} else {
1326		status = -ENOSPC;
1327		/* No error log here -- see the comment above
1328		 * ocfs2_test_bg_bit_allocatable */
1329	}
1330
1331	return status;
1332}
1333
1334int ocfs2_block_group_set_bits(handle_t *handle,
1335					     struct inode *alloc_inode,
1336					     struct ocfs2_group_desc *bg,
1337					     struct buffer_head *group_bh,
1338					     unsigned int bit_off,
1339					     unsigned int num_bits)
1340{
1341	int status;
1342	void *bitmap = bg->bg_bitmap;
1343	int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1344
1345	/* All callers get the descriptor via
1346	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1347	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1348	BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
1349
1350	trace_ocfs2_block_group_set_bits(bit_off, num_bits);
1351
1352	if (ocfs2_is_cluster_bitmap(alloc_inode))
1353		journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1354
1355	status = ocfs2_journal_access_gd(handle,
1356					 INODE_CACHE(alloc_inode),
1357					 group_bh,
1358					 journal_type);
1359	if (status < 0) {
1360		mlog_errno(status);
1361		goto bail;
1362	}
1363
1364	le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
1365	if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
1366		return ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit count %u but claims %u are freed. num_bits %d\n",
1367				   (unsigned long long)le64_to_cpu(bg->bg_blkno),
1368				   le16_to_cpu(bg->bg_bits),
1369				   le16_to_cpu(bg->bg_free_bits_count),
1370				   num_bits);
1371	}
1372	while(num_bits--)
1373		ocfs2_set_bit(bit_off++, bitmap);
1374
1375	ocfs2_journal_dirty(handle, group_bh);
1376
1377bail:
1378	return status;
1379}
1380
1381/* find the one with the most empty bits */
1382static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
1383{
1384	u16 curr, best;
1385
1386	BUG_ON(!cl->cl_next_free_rec);
1387
1388	best = curr = 0;
1389	while (curr < le16_to_cpu(cl->cl_next_free_rec)) {
1390		if (le32_to_cpu(cl->cl_recs[curr].c_free) >
1391		    le32_to_cpu(cl->cl_recs[best].c_free))
1392			best = curr;
1393		curr++;
1394	}
1395
1396	BUG_ON(best >= le16_to_cpu(cl->cl_next_free_rec));
1397	return best;
1398}
1399
1400static int ocfs2_relink_block_group(handle_t *handle,
1401				    struct inode *alloc_inode,
1402				    struct buffer_head *fe_bh,
1403				    struct buffer_head *bg_bh,
1404				    struct buffer_head *prev_bg_bh,
1405				    u16 chain)
1406{
1407	int status;
1408	/* there is a really tiny chance the journal calls could fail,
1409	 * but we wouldn't want inconsistent blocks in *any* case. */
1410	u64 bg_ptr, prev_bg_ptr;
1411	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
1412	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1413	struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
1414
1415	/* The caller got these descriptors from
1416	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1417	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1418	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(prev_bg));
1419
1420	trace_ocfs2_relink_block_group(
1421		(unsigned long long)le64_to_cpu(fe->i_blkno), chain,
1422		(unsigned long long)le64_to_cpu(bg->bg_blkno),
1423		(unsigned long long)le64_to_cpu(prev_bg->bg_blkno));
1424
1425	bg_ptr = le64_to_cpu(bg->bg_next_group);
1426	prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
1427
1428	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1429					 prev_bg_bh,
1430					 OCFS2_JOURNAL_ACCESS_WRITE);
1431	if (status < 0)
1432		goto out;
1433
1434	prev_bg->bg_next_group = bg->bg_next_group;
1435	ocfs2_journal_dirty(handle, prev_bg_bh);
1436
1437	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1438					 bg_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1439	if (status < 0)
1440		goto out_rollback_prev_bg;
1441
1442	bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
1443	ocfs2_journal_dirty(handle, bg_bh);
1444
1445	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
1446					 fe_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1447	if (status < 0)
1448		goto out_rollback_bg;
1449
1450	fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
1451	ocfs2_journal_dirty(handle, fe_bh);
1452
1453out:
1454	if (status < 0)
1455		mlog_errno(status);
1456	return status;
1457
1458out_rollback_bg:
1459	bg->bg_next_group = cpu_to_le64(bg_ptr);
1460out_rollback_prev_bg:
1461	prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
1462	goto out;
1463}
1464
1465static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
1466						     u32 wanted)
1467{
1468	return le16_to_cpu(bg->bg_free_bits_count) > wanted;
1469}
1470
1471/* return 0 on success, -ENOSPC to keep searching and any other < 0
1472 * value on error. */
1473static int ocfs2_cluster_group_search(struct inode *inode,
1474				      struct buffer_head *group_bh,
1475				      u32 bits_wanted, u32 min_bits,
1476				      u64 max_block,
1477				      struct ocfs2_suballoc_result *res)
1478{
1479	int search = -ENOSPC;
1480	int ret;
1481	u64 blkoff;
1482	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
1483	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1484	unsigned int max_bits, gd_cluster_off;
1485
1486	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1487
1488	if (gd->bg_free_bits_count) {
1489		max_bits = le16_to_cpu(gd->bg_bits);
1490
1491		/* Tail groups in cluster bitmaps which aren't cpg
1492		 * aligned are prone to partial extension by a failed
1493		 * fs resize. If the file system resize never got to
1494		 * update the dinode cluster count, then we don't want
1495		 * to trust any clusters past it, regardless of what
1496		 * the group descriptor says. */
1497		gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
1498							  le64_to_cpu(gd->bg_blkno));
1499		if ((gd_cluster_off + max_bits) >
1500		    OCFS2_I(inode)->ip_clusters) {
1501			max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
1502			trace_ocfs2_cluster_group_search_wrong_max_bits(
1503				(unsigned long long)le64_to_cpu(gd->bg_blkno),
1504				le16_to_cpu(gd->bg_bits),
1505				OCFS2_I(inode)->ip_clusters, max_bits);
1506		}
1507
1508		ret = ocfs2_block_group_find_clear_bits(osb,
1509							group_bh, bits_wanted,
1510							max_bits, res);
1511		if (ret)
1512			return ret;
1513
1514		if (max_block) {
1515			blkoff = ocfs2_clusters_to_blocks(inode->i_sb,
1516							  gd_cluster_off +
1517							  res->sr_bit_offset +
1518							  res->sr_bits);
1519			trace_ocfs2_cluster_group_search_max_block(
1520				(unsigned long long)blkoff,
1521				(unsigned long long)max_block);
1522			if (blkoff > max_block)
1523				return -ENOSPC;
1524		}
1525
1526		/* ocfs2_block_group_find_clear_bits() might
1527		 * return success, but we still want to return
1528		 * -ENOSPC unless it found the minimum number
1529		 * of bits. */
1530		if (min_bits <= res->sr_bits)
1531			search = 0; /* success */
1532		else if (res->sr_bits) {
1533			/*
1534			 * Don't show bits which we'll be returning
1535			 * for allocation to the local alloc bitmap.
1536			 */
1537			ocfs2_local_alloc_seen_free_bits(osb, res->sr_bits);
1538		}
1539	}
1540
1541	return search;
1542}
1543
1544static int ocfs2_block_group_search(struct inode *inode,
1545				    struct buffer_head *group_bh,
1546				    u32 bits_wanted, u32 min_bits,
1547				    u64 max_block,
1548				    struct ocfs2_suballoc_result *res)
1549{
1550	int ret = -ENOSPC;
1551	u64 blkoff;
1552	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
1553
1554	BUG_ON(min_bits != 1);
1555	BUG_ON(ocfs2_is_cluster_bitmap(inode));
1556
1557	if (bg->bg_free_bits_count) {
1558		ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1559							group_bh, bits_wanted,
1560							le16_to_cpu(bg->bg_bits),
1561							res);
1562		if (!ret && max_block) {
1563			blkoff = le64_to_cpu(bg->bg_blkno) +
1564				res->sr_bit_offset + res->sr_bits;
1565			trace_ocfs2_block_group_search_max_block(
1566				(unsigned long long)blkoff,
1567				(unsigned long long)max_block);
1568			if (blkoff > max_block)
1569				ret = -ENOSPC;
1570		}
1571	}
1572
1573	return ret;
1574}
1575
1576int ocfs2_alloc_dinode_update_counts(struct inode *inode,
1577				       handle_t *handle,
1578				       struct buffer_head *di_bh,
1579				       u32 num_bits,
1580				       u16 chain)
1581{
1582	int ret;
1583	u32 tmp_used;
1584	struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1585	struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &di->id2.i_chain;
1586
1587	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
1588				      OCFS2_JOURNAL_ACCESS_WRITE);
1589	if (ret < 0) {
1590		mlog_errno(ret);
1591		goto out;
1592	}
1593
1594	tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1595	di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
1596	le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
1597	ocfs2_journal_dirty(handle, di_bh);
1598
1599out:
1600	return ret;
1601}
1602
1603void ocfs2_rollback_alloc_dinode_counts(struct inode *inode,
1604				       struct buffer_head *di_bh,
1605				       u32 num_bits,
1606				       u16 chain)
1607{
1608	u32 tmp_used;
1609	struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1610	struct ocfs2_chain_list *cl;
1611
1612	cl = (struct ocfs2_chain_list *)&di->id2.i_chain;
1613	tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1614	di->id1.bitmap1.i_used = cpu_to_le32(tmp_used - num_bits);
1615	le32_add_cpu(&cl->cl_recs[chain].c_free, num_bits);
1616}
1617
1618static int ocfs2_bg_discontig_fix_by_rec(struct ocfs2_suballoc_result *res,
1619					 struct ocfs2_extent_rec *rec,
1620					 struct ocfs2_chain_list *cl)
1621{
1622	unsigned int bpc = le16_to_cpu(cl->cl_bpc);
1623	unsigned int bitoff = le32_to_cpu(rec->e_cpos) * bpc;
1624	unsigned int bitcount = le16_to_cpu(rec->e_leaf_clusters) * bpc;
1625
1626	if (res->sr_bit_offset < bitoff)
1627		return 0;
1628	if (res->sr_bit_offset >= (bitoff + bitcount))
1629		return 0;
1630	res->sr_blkno = le64_to_cpu(rec->e_blkno) +
1631		(res->sr_bit_offset - bitoff);
1632	if ((res->sr_bit_offset + res->sr_bits) > (bitoff + bitcount))
1633		res->sr_bits = (bitoff + bitcount) - res->sr_bit_offset;
1634	return 1;
1635}
1636
1637static void ocfs2_bg_discontig_fix_result(struct ocfs2_alloc_context *ac,
1638					  struct ocfs2_group_desc *bg,
1639					  struct ocfs2_suballoc_result *res)
1640{
1641	int i;
1642	u64 bg_blkno = res->sr_bg_blkno;  /* Save off */
1643	struct ocfs2_extent_rec *rec;
1644	struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1645	struct ocfs2_chain_list *cl = &di->id2.i_chain;
1646
1647	if (ocfs2_is_cluster_bitmap(ac->ac_inode)) {
1648		res->sr_blkno = 0;
1649		return;
1650	}
1651
1652	res->sr_blkno = res->sr_bg_blkno + res->sr_bit_offset;
1653	res->sr_bg_blkno = 0;  /* Clear it for contig block groups */
1654	if (!ocfs2_supports_discontig_bg(OCFS2_SB(ac->ac_inode->i_sb)) ||
1655	    !bg->bg_list.l_next_free_rec)
1656		return;
1657
1658	for (i = 0; i < le16_to_cpu(bg->bg_list.l_next_free_rec); i++) {
1659		rec = &bg->bg_list.l_recs[i];
1660		if (ocfs2_bg_discontig_fix_by_rec(res, rec, cl)) {
1661			res->sr_bg_blkno = bg_blkno;  /* Restore */
1662			break;
1663		}
1664	}
1665}
1666
1667static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
1668				  handle_t *handle,
1669				  u32 bits_wanted,
1670				  u32 min_bits,
1671				  struct ocfs2_suballoc_result *res,
1672				  u16 *bits_left)
1673{
1674	int ret;
1675	struct buffer_head *group_bh = NULL;
1676	struct ocfs2_group_desc *gd;
1677	struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1678	struct inode *alloc_inode = ac->ac_inode;
1679
1680	ret = ocfs2_read_group_descriptor(alloc_inode, di,
1681					  res->sr_bg_blkno, &group_bh);
1682	if (ret < 0) {
1683		mlog_errno(ret);
1684		return ret;
1685	}
1686
1687	gd = (struct ocfs2_group_desc *) group_bh->b_data;
1688	ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
1689				  ac->ac_max_block, res);
1690	if (ret < 0) {
1691		if (ret != -ENOSPC)
1692			mlog_errno(ret);
1693		goto out;
1694	}
1695
1696	if (!ret)
1697		ocfs2_bg_discontig_fix_result(ac, gd, res);
1698
1699	/*
1700	 * sr_bg_blkno might have been changed by
1701	 * ocfs2_bg_discontig_fix_result
1702	 */
1703	res->sr_bg_stable_blkno = group_bh->b_blocknr;
1704
1705	if (ac->ac_find_loc_only)
1706		goto out_loc_only;
1707
1708	ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
1709					       res->sr_bits,
1710					       le16_to_cpu(gd->bg_chain));
1711	if (ret < 0) {
1712		mlog_errno(ret);
1713		goto out;
1714	}
1715
1716	ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
1717					 res->sr_bit_offset, res->sr_bits);
1718	if (ret < 0) {
1719		ocfs2_rollback_alloc_dinode_counts(alloc_inode, ac->ac_bh,
1720					       res->sr_bits,
1721					       le16_to_cpu(gd->bg_chain));
1722		mlog_errno(ret);
1723	}
1724
1725out_loc_only:
1726	*bits_left = le16_to_cpu(gd->bg_free_bits_count);
1727
1728out:
1729	brelse(group_bh);
1730
1731	return ret;
1732}
1733
1734static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
1735			      handle_t *handle,
1736			      u32 bits_wanted,
1737			      u32 min_bits,
1738			      struct ocfs2_suballoc_result *res,
1739			      u16 *bits_left)
1740{
1741	int status;
1742	u16 chain;
1743	u64 next_group;
1744	struct inode *alloc_inode = ac->ac_inode;
1745	struct buffer_head *group_bh = NULL;
1746	struct buffer_head *prev_group_bh = NULL;
1747	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1748	struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1749	struct ocfs2_group_desc *bg;
1750
1751	chain = ac->ac_chain;
1752	trace_ocfs2_search_chain_begin(
1753		(unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
1754		bits_wanted, chain);
1755
1756	status = ocfs2_read_group_descriptor(alloc_inode, fe,
1757					     le64_to_cpu(cl->cl_recs[chain].c_blkno),
1758					     &group_bh);
1759	if (status < 0) {
1760		mlog_errno(status);
1761		goto bail;
1762	}
1763	bg = (struct ocfs2_group_desc *) group_bh->b_data;
1764
1765	status = -ENOSPC;
1766	/* for now, the chain search is a bit simplistic. We just use
1767	 * the 1st group with any empty bits. */
1768	while ((status = ac->ac_group_search(alloc_inode, group_bh,
1769					     bits_wanted, min_bits,
1770					     ac->ac_max_block,
1771					     res)) == -ENOSPC) {
1772		if (!bg->bg_next_group)
1773			break;
1774
1775		brelse(prev_group_bh);
1776		prev_group_bh = NULL;
1777
1778		next_group = le64_to_cpu(bg->bg_next_group);
1779		prev_group_bh = group_bh;
1780		group_bh = NULL;
1781		status = ocfs2_read_group_descriptor(alloc_inode, fe,
1782						     next_group, &group_bh);
1783		if (status < 0) {
1784			mlog_errno(status);
1785			goto bail;
1786		}
1787		bg = (struct ocfs2_group_desc *) group_bh->b_data;
1788	}
1789	if (status < 0) {
1790		if (status != -ENOSPC)
1791			mlog_errno(status);
1792		goto bail;
1793	}
1794
1795	trace_ocfs2_search_chain_succ(
1796		(unsigned long long)le64_to_cpu(bg->bg_blkno), res->sr_bits);
1797
1798	res->sr_bg_blkno = le64_to_cpu(bg->bg_blkno);
1799
1800	BUG_ON(res->sr_bits == 0);
1801	if (!status)
1802		ocfs2_bg_discontig_fix_result(ac, bg, res);
1803
1804	/*
1805	 * sr_bg_blkno might have been changed by
1806	 * ocfs2_bg_discontig_fix_result
1807	 */
1808	res->sr_bg_stable_blkno = group_bh->b_blocknr;
1809
1810	/*
1811	 * Keep track of previous block descriptor read. When
1812	 * we find a target, if we have read more than X
1813	 * number of descriptors, and the target is reasonably
1814	 * empty, relink him to top of his chain.
1815	 *
1816	 * We've read 0 extra blocks and only send one more to
1817	 * the transaction, yet the next guy to search has a
1818	 * much easier time.
1819	 *
1820	 * Do this *after* figuring out how many bits we're taking out
1821	 * of our target group.
1822	 */
1823	if (!ac->ac_disable_chain_relink &&
1824	    (prev_group_bh) &&
1825	    (ocfs2_block_group_reasonably_empty(bg, res->sr_bits))) {
1826		status = ocfs2_relink_block_group(handle, alloc_inode,
1827						  ac->ac_bh, group_bh,
1828						  prev_group_bh, chain);
1829		if (status < 0) {
1830			mlog_errno(status);
1831			goto bail;
1832		}
1833	}
1834
1835	if (ac->ac_find_loc_only)
1836		goto out_loc_only;
1837
1838	status = ocfs2_alloc_dinode_update_counts(alloc_inode, handle,
1839						  ac->ac_bh, res->sr_bits,
1840						  chain);
1841	if (status) {
1842		mlog_errno(status);
1843		goto bail;
1844	}
1845
1846	status = ocfs2_block_group_set_bits(handle,
1847					    alloc_inode,
1848					    bg,
1849					    group_bh,
1850					    res->sr_bit_offset,
1851					    res->sr_bits);
1852	if (status < 0) {
1853		ocfs2_rollback_alloc_dinode_counts(alloc_inode,
1854					ac->ac_bh, res->sr_bits, chain);
1855		mlog_errno(status);
1856		goto bail;
1857	}
1858
1859	trace_ocfs2_search_chain_end(
1860			(unsigned long long)le64_to_cpu(fe->i_blkno),
1861			res->sr_bits);
1862
1863out_loc_only:
1864	*bits_left = le16_to_cpu(bg->bg_free_bits_count);
1865bail:
1866	brelse(group_bh);
1867	brelse(prev_group_bh);
1868
1869	if (status)
1870		mlog_errno(status);
1871	return status;
1872}
1873
1874/* will give out up to bits_wanted contiguous bits. */
1875static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
1876				     handle_t *handle,
1877				     u32 bits_wanted,
1878				     u32 min_bits,
1879				     struct ocfs2_suballoc_result *res)
1880{
1881	int status;
1882	u16 victim, i;
1883	u16 bits_left = 0;
1884	u64 hint = ac->ac_last_group;
1885	struct ocfs2_chain_list *cl;
1886	struct ocfs2_dinode *fe;
1887
1888	BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1889	BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1890	BUG_ON(!ac->ac_bh);
1891
1892	fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1893
1894	/* The bh was validated by the inode read during
1895	 * ocfs2_reserve_suballoc_bits().  Any corruption is a code bug. */
1896	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
1897
1898	if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1899	    le32_to_cpu(fe->id1.bitmap1.i_total)) {
1900		status = ocfs2_error(ac->ac_inode->i_sb,
1901				     "Chain allocator dinode %llu has %u used bits but only %u total\n",
1902				     (unsigned long long)le64_to_cpu(fe->i_blkno),
1903				     le32_to_cpu(fe->id1.bitmap1.i_used),
1904				     le32_to_cpu(fe->id1.bitmap1.i_total));
1905		goto bail;
1906	}
1907
1908	res->sr_bg_blkno = hint;
1909	if (res->sr_bg_blkno) {
1910		/* Attempt to short-circuit the usual search mechanism
1911		 * by jumping straight to the most recently used
1912		 * allocation group. This helps us maintain some
1913		 * contiguousness across allocations. */
1914		status = ocfs2_search_one_group(ac, handle, bits_wanted,
1915						min_bits, res, &bits_left);
1916		if (!status)
1917			goto set_hint;
1918		if (status < 0 && status != -ENOSPC) {
1919			mlog_errno(status);
1920			goto bail;
1921		}
1922	}
1923
1924	cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1925
1926	victim = ocfs2_find_victim_chain(cl);
1927	ac->ac_chain = victim;
1928
1929	status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1930				    res, &bits_left);
1931	if (!status) {
1932		if (ocfs2_is_cluster_bitmap(ac->ac_inode))
1933			hint = res->sr_bg_blkno;
1934		else
1935			hint = ocfs2_group_from_res(res);
1936		goto set_hint;
1937	}
1938	if (status < 0 && status != -ENOSPC) {
1939		mlog_errno(status);
1940		goto bail;
1941	}
1942
1943	trace_ocfs2_claim_suballoc_bits(victim);
1944
1945	/* If we didn't pick a good victim, then just default to
1946	 * searching each chain in order. Don't allow chain relinking
1947	 * because we only calculate enough journal credits for one
1948	 * relink per alloc. */
1949	ac->ac_disable_chain_relink = 1;
1950	for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
1951		if (i == victim)
1952			continue;
1953		if (!cl->cl_recs[i].c_free)
1954			continue;
1955
1956		ac->ac_chain = i;
1957		status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1958					    res, &bits_left);
1959		if (!status) {
1960			hint = ocfs2_group_from_res(res);
1961			break;
1962		}
1963		if (status < 0 && status != -ENOSPC) {
1964			mlog_errno(status);
1965			goto bail;
1966		}
1967	}
1968
1969set_hint:
1970	if (status != -ENOSPC) {
1971		/* If the next search of this group is not likely to
1972		 * yield a suitable extent, then we reset the last
1973		 * group hint so as to not waste a disk read */
1974		if (bits_left < min_bits)
1975			ac->ac_last_group = 0;
1976		else
1977			ac->ac_last_group = hint;
1978	}
1979
1980bail:
1981	if (status)
1982		mlog_errno(status);
1983	return status;
1984}
1985
1986int ocfs2_claim_metadata(handle_t *handle,
1987			 struct ocfs2_alloc_context *ac,
1988			 u32 bits_wanted,
1989			 u64 *suballoc_loc,
1990			 u16 *suballoc_bit_start,
1991			 unsigned int *num_bits,
1992			 u64 *blkno_start)
1993{
1994	int status;
1995	struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
1996
1997	BUG_ON(!ac);
1998	BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
1999	BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
2000
2001	status = ocfs2_claim_suballoc_bits(ac,
2002					   handle,
2003					   bits_wanted,
2004					   1,
2005					   &res);
2006	if (status < 0) {
2007		mlog_errno(status);
2008		goto bail;
2009	}
2010	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2011
2012	*suballoc_loc = res.sr_bg_blkno;
2013	*suballoc_bit_start = res.sr_bit_offset;
2014	*blkno_start = res.sr_blkno;
2015	ac->ac_bits_given += res.sr_bits;
2016	*num_bits = res.sr_bits;
2017	status = 0;
2018bail:
2019	if (status)
2020		mlog_errno(status);
2021	return status;
2022}
2023
2024static void ocfs2_init_inode_ac_group(struct inode *dir,
2025				      struct buffer_head *parent_di_bh,
2026				      struct ocfs2_alloc_context *ac)
2027{
2028	struct ocfs2_dinode *di = (struct ocfs2_dinode *)parent_di_bh->b_data;
2029	/*
2030	 * Try to allocate inodes from some specific group.
2031	 *
2032	 * If the parent dir has recorded the last group used in allocation,
2033	 * cool, use it. Otherwise if we try to allocate new inode from the
2034	 * same slot the parent dir belongs to, use the same chunk.
2035	 *
2036	 * We are very careful here to avoid the mistake of setting
2037	 * ac_last_group to a group descriptor from a different (unlocked) slot.
2038	 */
2039	if (OCFS2_I(dir)->ip_last_used_group &&
2040	    OCFS2_I(dir)->ip_last_used_slot == ac->ac_alloc_slot)
2041		ac->ac_last_group = OCFS2_I(dir)->ip_last_used_group;
2042	else if (le16_to_cpu(di->i_suballoc_slot) == ac->ac_alloc_slot) {
2043		if (di->i_suballoc_loc)
2044			ac->ac_last_group = le64_to_cpu(di->i_suballoc_loc);
2045		else
2046			ac->ac_last_group = ocfs2_which_suballoc_group(
2047					le64_to_cpu(di->i_blkno),
2048					le16_to_cpu(di->i_suballoc_bit));
2049	}
2050}
2051
2052static inline void ocfs2_save_inode_ac_group(struct inode *dir,
2053					     struct ocfs2_alloc_context *ac)
2054{
2055	OCFS2_I(dir)->ip_last_used_group = ac->ac_last_group;
2056	OCFS2_I(dir)->ip_last_used_slot = ac->ac_alloc_slot;
2057}
2058
2059int ocfs2_find_new_inode_loc(struct inode *dir,
2060			     struct buffer_head *parent_fe_bh,
2061			     struct ocfs2_alloc_context *ac,
2062			     u64 *fe_blkno)
2063{
2064	int ret;
2065	handle_t *handle = NULL;
2066	struct ocfs2_suballoc_result *res;
2067
2068	BUG_ON(!ac);
2069	BUG_ON(ac->ac_bits_given != 0);
2070	BUG_ON(ac->ac_bits_wanted != 1);
2071	BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2072
2073	res = kzalloc(sizeof(*res), GFP_NOFS);
2074	if (res == NULL) {
2075		ret = -ENOMEM;
2076		mlog_errno(ret);
2077		goto out;
2078	}
2079
2080	ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2081
2082	/*
2083	 * The handle started here is for chain relink. Alternatively,
2084	 * we could just disable relink for these calls.
2085	 */
2086	handle = ocfs2_start_trans(OCFS2_SB(dir->i_sb), OCFS2_SUBALLOC_ALLOC);
2087	if (IS_ERR(handle)) {
2088		ret = PTR_ERR(handle);
2089		handle = NULL;
2090		mlog_errno(ret);
2091		goto out;
2092	}
2093
2094	/*
2095	 * This will instruct ocfs2_claim_suballoc_bits and
2096	 * ocfs2_search_one_group to search but save actual allocation
2097	 * for later.
2098	 */
2099	ac->ac_find_loc_only = 1;
2100
2101	ret = ocfs2_claim_suballoc_bits(ac, handle, 1, 1, res);
2102	if (ret < 0) {
2103		mlog_errno(ret);
2104		goto out;
2105	}
2106
2107	ac->ac_find_loc_priv = res;
2108	*fe_blkno = res->sr_blkno;
2109	ocfs2_update_inode_fsync_trans(handle, dir, 0);
2110out:
2111	if (handle)
2112		ocfs2_commit_trans(OCFS2_SB(dir->i_sb), handle);
2113
2114	if (ret)
2115		kfree(res);
2116
2117	return ret;
2118}
2119
2120int ocfs2_claim_new_inode_at_loc(handle_t *handle,
2121				 struct inode *dir,
2122				 struct ocfs2_alloc_context *ac,
2123				 u64 *suballoc_loc,
2124				 u16 *suballoc_bit,
2125				 u64 di_blkno)
2126{
2127	int ret;
2128	u16 chain;
2129	struct ocfs2_suballoc_result *res = ac->ac_find_loc_priv;
2130	struct buffer_head *bg_bh = NULL;
2131	struct ocfs2_group_desc *bg;
2132	struct ocfs2_dinode *di = (struct ocfs2_dinode *) ac->ac_bh->b_data;
2133
2134	/*
2135	 * Since di_blkno is being passed back in, we check for any
2136	 * inconsistencies which may have happened between
2137	 * calls. These are code bugs as di_blkno is not expected to
2138	 * change once returned from ocfs2_find_new_inode_loc()
2139	 */
2140	BUG_ON(res->sr_blkno != di_blkno);
2141
2142	ret = ocfs2_read_group_descriptor(ac->ac_inode, di,
2143					  res->sr_bg_stable_blkno, &bg_bh);
2144	if (ret) {
2145		mlog_errno(ret);
2146		goto out;
2147	}
2148
2149	bg = (struct ocfs2_group_desc *) bg_bh->b_data;
2150	chain = le16_to_cpu(bg->bg_chain);
2151
2152	ret = ocfs2_alloc_dinode_update_counts(ac->ac_inode, handle,
2153					       ac->ac_bh, res->sr_bits,
2154					       chain);
2155	if (ret) {
2156		mlog_errno(ret);
2157		goto out;
2158	}
2159
2160	ret = ocfs2_block_group_set_bits(handle,
2161					 ac->ac_inode,
2162					 bg,
2163					 bg_bh,
2164					 res->sr_bit_offset,
2165					 res->sr_bits);
2166	if (ret < 0) {
2167		ocfs2_rollback_alloc_dinode_counts(ac->ac_inode,
2168					       ac->ac_bh, res->sr_bits, chain);
2169		mlog_errno(ret);
2170		goto out;
2171	}
2172
2173	trace_ocfs2_claim_new_inode_at_loc((unsigned long long)di_blkno,
2174					   res->sr_bits);
2175
2176	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2177
2178	BUG_ON(res->sr_bits != 1);
2179
2180	*suballoc_loc = res->sr_bg_blkno;
2181	*suballoc_bit = res->sr_bit_offset;
2182	ac->ac_bits_given++;
2183	ocfs2_save_inode_ac_group(dir, ac);
2184
2185out:
2186	brelse(bg_bh);
2187
2188	return ret;
2189}
2190
2191int ocfs2_claim_new_inode(handle_t *handle,
2192			  struct inode *dir,
2193			  struct buffer_head *parent_fe_bh,
2194			  struct ocfs2_alloc_context *ac,
2195			  u64 *suballoc_loc,
2196			  u16 *suballoc_bit,
2197			  u64 *fe_blkno)
2198{
2199	int status;
2200	struct ocfs2_suballoc_result res;
2201
2202	BUG_ON(!ac);
2203	BUG_ON(ac->ac_bits_given != 0);
2204	BUG_ON(ac->ac_bits_wanted != 1);
2205	BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2206
2207	ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2208
2209	status = ocfs2_claim_suballoc_bits(ac,
2210					   handle,
2211					   1,
2212					   1,
2213					   &res);
2214	if (status < 0) {
2215		mlog_errno(status);
2216		goto bail;
2217	}
2218	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2219
2220	BUG_ON(res.sr_bits != 1);
2221
2222	*suballoc_loc = res.sr_bg_blkno;
2223	*suballoc_bit = res.sr_bit_offset;
2224	*fe_blkno = res.sr_blkno;
2225	ac->ac_bits_given++;
2226	ocfs2_save_inode_ac_group(dir, ac);
2227	status = 0;
2228bail:
2229	if (status)
2230		mlog_errno(status);
2231	return status;
2232}
2233
2234/* translate a group desc. blkno and it's bitmap offset into
2235 * disk cluster offset. */
2236static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
2237						   u64 bg_blkno,
2238						   u16 bg_bit_off)
2239{
2240	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2241	u32 cluster = 0;
2242
2243	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2244
2245	if (bg_blkno != osb->first_cluster_group_blkno)
2246		cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
2247	cluster += (u32) bg_bit_off;
2248	return cluster;
2249}
2250
2251/* given a cluster offset, calculate which block group it belongs to
2252 * and return that block offset. */
2253u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster)
2254{
2255	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2256	u32 group_no;
2257
2258	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2259
2260	group_no = cluster / osb->bitmap_cpg;
2261	if (!group_no)
2262		return osb->first_cluster_group_blkno;
2263	return ocfs2_clusters_to_blocks(inode->i_sb,
2264					group_no * osb->bitmap_cpg);
2265}
2266
2267/* given the block number of a cluster start, calculate which cluster
2268 * group and descriptor bitmap offset that corresponds to. */
2269static inline void ocfs2_block_to_cluster_group(struct inode *inode,
2270						u64 data_blkno,
2271						u64 *bg_blkno,
2272						u16 *bg_bit_off)
2273{
2274	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2275	u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
2276
2277	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2278
2279	*bg_blkno = ocfs2_which_cluster_group(inode,
2280					      data_cluster);
2281
2282	if (*bg_blkno == osb->first_cluster_group_blkno)
2283		*bg_bit_off = (u16) data_cluster;
2284	else
2285		*bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
2286							     data_blkno - *bg_blkno);
2287}
2288
2289/*
2290 * min_bits - minimum contiguous chunk from this total allocation we
2291 * can handle. set to what we asked for originally for a full
2292 * contig. allocation, set to '1' to indicate we can deal with extents
2293 * of any size.
2294 */
2295int __ocfs2_claim_clusters(handle_t *handle,
2296			   struct ocfs2_alloc_context *ac,
2297			   u32 min_clusters,
2298			   u32 max_clusters,
2299			   u32 *cluster_start,
2300			   u32 *num_clusters)
2301{
2302	int status;
2303	unsigned int bits_wanted = max_clusters;
2304	struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
2305	struct ocfs2_super *osb = OCFS2_SB(ac->ac_inode->i_sb);
2306
2307	BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
2308
2309	BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
2310	       && ac->ac_which != OCFS2_AC_USE_MAIN);
2311
2312	if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
2313		WARN_ON(min_clusters > 1);
2314
2315		status = ocfs2_claim_local_alloc_bits(osb,
2316						      handle,
2317						      ac,
2318						      bits_wanted,
2319						      cluster_start,
2320						      num_clusters);
2321		if (!status)
2322			atomic_inc(&osb->alloc_stats.local_data);
2323	} else {
2324		if (min_clusters > (osb->bitmap_cpg - 1)) {
2325			/* The only paths asking for contiguousness
2326			 * should know about this already. */
2327			mlog(ML_ERROR, "minimum allocation requested %u exceeds "
2328			     "group bitmap size %u!\n", min_clusters,
2329			     osb->bitmap_cpg);
2330			status = -ENOSPC;
2331			goto bail;
2332		}
2333		/* clamp the current request down to a realistic size. */
2334		if (bits_wanted > (osb->bitmap_cpg - 1))
2335			bits_wanted = osb->bitmap_cpg - 1;
2336
2337		status = ocfs2_claim_suballoc_bits(ac,
2338						   handle,
2339						   bits_wanted,
2340						   min_clusters,
2341						   &res);
2342		if (!status) {
2343			BUG_ON(res.sr_blkno); /* cluster alloc can't set */
2344			*cluster_start =
2345				ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
2346								 res.sr_bg_blkno,
2347								 res.sr_bit_offset);
2348			atomic_inc(&osb->alloc_stats.bitmap_data);
2349			*num_clusters = res.sr_bits;
2350		}
2351	}
2352	if (status < 0) {
2353		if (status != -ENOSPC)
2354			mlog_errno(status);
2355		goto bail;
2356	}
2357
2358	ac->ac_bits_given += *num_clusters;
2359
2360bail:
2361	if (status)
2362		mlog_errno(status);
2363	return status;
2364}
2365
2366int ocfs2_claim_clusters(handle_t *handle,
2367			 struct ocfs2_alloc_context *ac,
2368			 u32 min_clusters,
2369			 u32 *cluster_start,
2370			 u32 *num_clusters)
2371{
2372	unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
2373
2374	return __ocfs2_claim_clusters(handle, ac, min_clusters,
2375				      bits_wanted, cluster_start, num_clusters);
2376}
2377
2378static int ocfs2_block_group_clear_bits(handle_t *handle,
2379					struct inode *alloc_inode,
2380					struct ocfs2_group_desc *bg,
2381					struct buffer_head *group_bh,
2382					unsigned int bit_off,
2383					unsigned int num_bits,
2384					void (*undo_fn)(unsigned int bit,
2385							unsigned long *bmap))
2386{
2387	int status;
2388	unsigned int tmp;
2389	struct ocfs2_group_desc *undo_bg = NULL;
2390
2391	/* The caller got this descriptor from
2392	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
2393	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
2394
2395	trace_ocfs2_block_group_clear_bits(bit_off, num_bits);
2396
2397	BUG_ON(undo_fn && !ocfs2_is_cluster_bitmap(alloc_inode));
2398	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
2399					 group_bh,
2400					 undo_fn ?
2401					 OCFS2_JOURNAL_ACCESS_UNDO :
2402					 OCFS2_JOURNAL_ACCESS_WRITE);
2403	if (status < 0) {
2404		mlog_errno(status);
2405		goto bail;
2406	}
2407
2408	if (undo_fn) {
2409		jbd_lock_bh_state(group_bh);
2410		undo_bg = (struct ocfs2_group_desc *)
2411					bh2jh(group_bh)->b_committed_data;
2412		BUG_ON(!undo_bg);
2413	}
2414
2415	tmp = num_bits;
2416	while(tmp--) {
2417		ocfs2_clear_bit((bit_off + tmp),
2418				(unsigned long *) bg->bg_bitmap);
2419		if (undo_fn)
2420			undo_fn(bit_off + tmp,
2421				(unsigned long *) undo_bg->bg_bitmap);
2422	}
2423	le16_add_cpu(&bg->bg_free_bits_count, num_bits);
2424	if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
2425		if (undo_fn)
2426			jbd_unlock_bh_state(group_bh);
2427		return ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit count %u but claims %u are freed. num_bits %d\n",
2428				   (unsigned long long)le64_to_cpu(bg->bg_blkno),
2429				   le16_to_cpu(bg->bg_bits),
2430				   le16_to_cpu(bg->bg_free_bits_count),
2431				   num_bits);
2432	}
2433
2434	if (undo_fn)
2435		jbd_unlock_bh_state(group_bh);
2436
2437	ocfs2_journal_dirty(handle, group_bh);
2438bail:
2439	return status;
2440}
2441
2442/*
2443 * expects the suballoc inode to already be locked.
2444 */
2445static int _ocfs2_free_suballoc_bits(handle_t *handle,
2446				     struct inode *alloc_inode,
2447				     struct buffer_head *alloc_bh,
2448				     unsigned int start_bit,
2449				     u64 bg_blkno,
2450				     unsigned int count,
2451				     void (*undo_fn)(unsigned int bit,
2452						     unsigned long *bitmap))
2453{
2454	int status = 0;
2455	u32 tmp_used;
2456	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
2457	struct ocfs2_chain_list *cl = &fe->id2.i_chain;
2458	struct buffer_head *group_bh = NULL;
2459	struct ocfs2_group_desc *group;
2460
2461	/* The alloc_bh comes from ocfs2_free_dinode() or
2462	 * ocfs2_free_clusters().  The callers have all locked the
2463	 * allocator and gotten alloc_bh from the lock call.  This
2464	 * validates the dinode buffer.  Any corruption that has happened
2465	 * is a code bug. */
2466	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
2467	BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
2468
2469	trace_ocfs2_free_suballoc_bits(
2470		(unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
2471		(unsigned long long)bg_blkno,
2472		start_bit, count);
2473
2474	status = ocfs2_read_group_descriptor(alloc_inode, fe, bg_blkno,
2475					     &group_bh);
2476	if (status < 0) {
2477		mlog_errno(status);
2478		goto bail;
2479	}
2480	group = (struct ocfs2_group_desc *) group_bh->b_data;
2481
2482	BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
2483
2484	status = ocfs2_block_group_clear_bits(handle, alloc_inode,
2485					      group, group_bh,
2486					      start_bit, count, undo_fn);
2487	if (status < 0) {
2488		mlog_errno(status);
2489		goto bail;
2490	}
2491
2492	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
2493					 alloc_bh, OCFS2_JOURNAL_ACCESS_WRITE);
2494	if (status < 0) {
2495		mlog_errno(status);
2496		ocfs2_block_group_set_bits(handle, alloc_inode, group, group_bh,
2497				start_bit, count);
2498		goto bail;
2499	}
2500
2501	le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
2502		     count);
2503	tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
2504	fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
2505	ocfs2_journal_dirty(handle, alloc_bh);
2506
2507bail:
2508	brelse(group_bh);
2509
2510	if (status)
2511		mlog_errno(status);
2512	return status;
2513}
2514
2515int ocfs2_free_suballoc_bits(handle_t *handle,
2516			     struct inode *alloc_inode,
2517			     struct buffer_head *alloc_bh,
2518			     unsigned int start_bit,
2519			     u64 bg_blkno,
2520			     unsigned int count)
2521{
2522	return _ocfs2_free_suballoc_bits(handle, alloc_inode, alloc_bh,
2523					 start_bit, bg_blkno, count, NULL);
2524}
2525
2526int ocfs2_free_dinode(handle_t *handle,
2527		      struct inode *inode_alloc_inode,
2528		      struct buffer_head *inode_alloc_bh,
2529		      struct ocfs2_dinode *di)
2530{
2531	u64 blk = le64_to_cpu(di->i_blkno);
2532	u16 bit = le16_to_cpu(di->i_suballoc_bit);
2533	u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
2534
2535	if (di->i_suballoc_loc)
2536		bg_blkno = le64_to_cpu(di->i_suballoc_loc);
2537	return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
2538					inode_alloc_bh, bit, bg_blkno, 1);
2539}
2540
2541static int _ocfs2_free_clusters(handle_t *handle,
2542				struct inode *bitmap_inode,
2543				struct buffer_head *bitmap_bh,
2544				u64 start_blk,
2545				unsigned int num_clusters,
2546				void (*undo_fn)(unsigned int bit,
2547						unsigned long *bitmap))
2548{
2549	int status;
2550	u16 bg_start_bit;
2551	u64 bg_blkno;
2552
2553	/* You can't ever have a contiguous set of clusters
2554	 * bigger than a block group bitmap so we never have to worry
2555	 * about looping on them.
2556	 * This is expensive. We can safely remove once this stuff has
2557	 * gotten tested really well. */
2558	BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb,
2559				ocfs2_blocks_to_clusters(bitmap_inode->i_sb,
2560							 start_blk)));
2561
2562
2563	ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
2564				     &bg_start_bit);
2565
2566	trace_ocfs2_free_clusters((unsigned long long)bg_blkno,
2567			(unsigned long long)start_blk,
2568			bg_start_bit, num_clusters);
2569
2570	status = _ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
2571					   bg_start_bit, bg_blkno,
2572					   num_clusters, undo_fn);
2573	if (status < 0) {
2574		mlog_errno(status);
2575		goto out;
2576	}
2577
2578	ocfs2_local_alloc_seen_free_bits(OCFS2_SB(bitmap_inode->i_sb),
2579					 num_clusters);
2580
2581out:
2582	if (status)
2583		mlog_errno(status);
2584	return status;
2585}
2586
2587int ocfs2_free_clusters(handle_t *handle,
2588			struct inode *bitmap_inode,
2589			struct buffer_head *bitmap_bh,
2590			u64 start_blk,
2591			unsigned int num_clusters)
2592{
2593	return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2594				    start_blk, num_clusters,
2595				    _ocfs2_set_bit);
2596}
2597
2598/*
2599 * Give never-used clusters back to the global bitmap.  We don't need
2600 * to protect these bits in the undo buffer.
2601 */
2602int ocfs2_release_clusters(handle_t *handle,
2603			   struct inode *bitmap_inode,
2604			   struct buffer_head *bitmap_bh,
2605			   u64 start_blk,
2606			   unsigned int num_clusters)
2607{
2608	return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2609				    start_blk, num_clusters,
2610				    _ocfs2_clear_bit);
2611}
2612
2613/*
2614 * For a given allocation, determine which allocators will need to be
2615 * accessed, and lock them, reserving the appropriate number of bits.
2616 *
2617 * Sparse file systems call this from ocfs2_write_begin_nolock()
2618 * and ocfs2_allocate_unwritten_extents().
2619 *
2620 * File systems which don't support holes call this from
2621 * ocfs2_extend_allocation().
2622 */
2623int ocfs2_lock_allocators(struct inode *inode,
2624			  struct ocfs2_extent_tree *et,
2625			  u32 clusters_to_add, u32 extents_to_split,
2626			  struct ocfs2_alloc_context **data_ac,
2627			  struct ocfs2_alloc_context **meta_ac)
2628{
2629	int ret = 0, num_free_extents;
2630	unsigned int max_recs_needed = clusters_to_add + 2 * extents_to_split;
2631	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2632
2633	*meta_ac = NULL;
2634	if (data_ac)
2635		*data_ac = NULL;
2636
2637	BUG_ON(clusters_to_add != 0 && data_ac == NULL);
2638
2639	num_free_extents = ocfs2_num_free_extents(et);
2640	if (num_free_extents < 0) {
2641		ret = num_free_extents;
2642		mlog_errno(ret);
2643		goto out;
2644	}
2645
2646	/*
2647	 * Sparse allocation file systems need to be more conservative
2648	 * with reserving room for expansion - the actual allocation
2649	 * happens while we've got a journal handle open so re-taking
2650	 * a cluster lock (because we ran out of room for another
2651	 * extent) will violate ordering rules.
2652	 *
2653	 * Most of the time we'll only be seeing this 1 cluster at a time
2654	 * anyway.
2655	 *
2656	 * Always lock for any unwritten extents - we might want to
2657	 * add blocks during a split.
2658	 */
2659	if (!num_free_extents ||
2660	    (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed)) {
2661		ret = ocfs2_reserve_new_metadata(osb, et->et_root_el, meta_ac);
2662		if (ret < 0) {
2663			if (ret != -ENOSPC)
2664				mlog_errno(ret);
2665			goto out;
2666		}
2667	}
2668
2669	if (clusters_to_add == 0)
2670		goto out;
2671
2672	ret = ocfs2_reserve_clusters(osb, clusters_to_add, data_ac);
2673	if (ret < 0) {
2674		if (ret != -ENOSPC)
2675			mlog_errno(ret);
2676		goto out;
2677	}
2678
2679out:
2680	if (ret) {
2681		if (*meta_ac) {
2682			ocfs2_free_alloc_context(*meta_ac);
2683			*meta_ac = NULL;
2684		}
2685
2686		/*
2687		 * We cannot have an error and a non null *data_ac.
2688		 */
2689	}
2690
2691	return ret;
2692}
2693
2694/*
2695 * Read the inode specified by blkno to get suballoc_slot and
2696 * suballoc_bit.
2697 */
2698static int ocfs2_get_suballoc_slot_bit(struct ocfs2_super *osb, u64 blkno,
2699				       u16 *suballoc_slot, u64 *group_blkno,
2700				       u16 *suballoc_bit)
2701{
2702	int status;
2703	struct buffer_head *inode_bh = NULL;
2704	struct ocfs2_dinode *inode_fe;
2705
2706	trace_ocfs2_get_suballoc_slot_bit((unsigned long long)blkno);
2707
2708	/* dirty read disk */
2709	status = ocfs2_read_blocks_sync(osb, blkno, 1, &inode_bh);
2710	if (status < 0) {
2711		mlog(ML_ERROR, "read block %llu failed %d\n",
2712		     (unsigned long long)blkno, status);
2713		goto bail;
2714	}
2715
2716	inode_fe = (struct ocfs2_dinode *) inode_bh->b_data;
2717	if (!OCFS2_IS_VALID_DINODE(inode_fe)) {
2718		mlog(ML_ERROR, "invalid inode %llu requested\n",
2719		     (unsigned long long)blkno);
2720		status = -EINVAL;
2721		goto bail;
2722	}
2723
2724	if (le16_to_cpu(inode_fe->i_suballoc_slot) != (u16)OCFS2_INVALID_SLOT &&
2725	    (u32)le16_to_cpu(inode_fe->i_suballoc_slot) > osb->max_slots - 1) {
2726		mlog(ML_ERROR, "inode %llu has invalid suballoc slot %u\n",
2727		     (unsigned long long)blkno,
2728		     (u32)le16_to_cpu(inode_fe->i_suballoc_slot));
2729		status = -EINVAL;
2730		goto bail;
2731	}
2732
2733	if (suballoc_slot)
2734		*suballoc_slot = le16_to_cpu(inode_fe->i_suballoc_slot);
2735	if (suballoc_bit)
2736		*suballoc_bit = le16_to_cpu(inode_fe->i_suballoc_bit);
2737	if (group_blkno)
2738		*group_blkno = le64_to_cpu(inode_fe->i_suballoc_loc);
2739
2740bail:
2741	brelse(inode_bh);
2742
2743	if (status)
2744		mlog_errno(status);
2745	return status;
2746}
2747
2748/*
2749 * test whether bit is SET in allocator bitmap or not.  on success, 0
2750 * is returned and *res is 1 for SET; 0 otherwise.  when fails, errno
2751 * is returned and *res is meaningless.  Call this after you have
2752 * cluster locked against suballoc, or you may get a result based on
2753 * non-up2date contents
2754 */
2755static int ocfs2_test_suballoc_bit(struct ocfs2_super *osb,
2756				   struct inode *suballoc,
2757				   struct buffer_head *alloc_bh,
2758				   u64 group_blkno, u64 blkno,
2759				   u16 bit, int *res)
2760{
2761	struct ocfs2_dinode *alloc_di;
2762	struct ocfs2_group_desc *group;
2763	struct buffer_head *group_bh = NULL;
2764	u64 bg_blkno;
2765	int status;
2766
2767	trace_ocfs2_test_suballoc_bit((unsigned long long)blkno,
2768				      (unsigned int)bit);
2769
2770	alloc_di = (struct ocfs2_dinode *)alloc_bh->b_data;
2771	if ((bit + 1) > ocfs2_bits_per_group(&alloc_di->id2.i_chain)) {
2772		mlog(ML_ERROR, "suballoc bit %u out of range of %u\n",
2773		     (unsigned int)bit,
2774		     ocfs2_bits_per_group(&alloc_di->id2.i_chain));
2775		status = -EINVAL;
2776		goto bail;
2777	}
2778
2779	bg_blkno = group_blkno ? group_blkno :
2780		   ocfs2_which_suballoc_group(blkno, bit);
2781	status = ocfs2_read_group_descriptor(suballoc, alloc_di, bg_blkno,
2782					     &group_bh);
2783	if (status < 0) {
2784		mlog(ML_ERROR, "read group %llu failed %d\n",
2785		     (unsigned long long)bg_blkno, status);
2786		goto bail;
2787	}
2788
2789	group = (struct ocfs2_group_desc *) group_bh->b_data;
2790	*res = ocfs2_test_bit(bit, (unsigned long *)group->bg_bitmap);
2791
2792bail:
2793	brelse(group_bh);
2794
2795	if (status)
2796		mlog_errno(status);
2797	return status;
2798}
2799
2800/*
2801 * Test if the bit representing this inode (blkno) is set in the
2802 * suballocator.
2803 *
2804 * On success, 0 is returned and *res is 1 for SET; 0 otherwise.
2805 *
2806 * In the event of failure, a negative value is returned and *res is
2807 * meaningless.
2808 *
2809 * Callers must make sure to hold nfs_sync_lock to prevent
2810 * ocfs2_delete_inode() on another node from accessing the same
2811 * suballocator concurrently.
2812 */
2813int ocfs2_test_inode_bit(struct ocfs2_super *osb, u64 blkno, int *res)
2814{
2815	int status;
2816	u64 group_blkno = 0;
2817	u16 suballoc_bit = 0, suballoc_slot = 0;
2818	struct inode *inode_alloc_inode;
2819	struct buffer_head *alloc_bh = NULL;
2820
2821	trace_ocfs2_test_inode_bit((unsigned long long)blkno);
2822
2823	status = ocfs2_get_suballoc_slot_bit(osb, blkno, &suballoc_slot,
2824					     &group_blkno, &suballoc_bit);
2825	if (status < 0) {
2826		mlog(ML_ERROR, "get alloc slot and bit failed %d\n", status);
2827		goto bail;
2828	}
2829
2830	inode_alloc_inode =
2831		ocfs2_get_system_file_inode(osb, INODE_ALLOC_SYSTEM_INODE,
2832					    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}
v4.17
 
   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 u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl);
  83static int ocfs2_block_group_fill(handle_t *handle,
  84				  struct inode *alloc_inode,
  85				  struct buffer_head *bg_bh,
  86				  u64 group_blkno,
  87				  unsigned int group_clusters,
  88				  u16 my_chain,
  89				  struct ocfs2_chain_list *cl);
  90static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
  91				   struct inode *alloc_inode,
  92				   struct buffer_head *bh,
  93				   u64 max_block,
  94				   u64 *last_alloc_group,
  95				   int flags);
  96
  97static int ocfs2_cluster_group_search(struct inode *inode,
  98				      struct buffer_head *group_bh,
  99				      u32 bits_wanted, u32 min_bits,
 100				      u64 max_block,
 101				      struct ocfs2_suballoc_result *res);
 102static int ocfs2_block_group_search(struct inode *inode,
 103				    struct buffer_head *group_bh,
 104				    u32 bits_wanted, u32 min_bits,
 105				    u64 max_block,
 106				    struct ocfs2_suballoc_result *res);
 107static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
 108				     handle_t *handle,
 109				     u32 bits_wanted,
 110				     u32 min_bits,
 111				     struct ocfs2_suballoc_result *res);
 112static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
 113					 int nr);
 114static int ocfs2_relink_block_group(handle_t *handle,
 115				    struct inode *alloc_inode,
 116				    struct buffer_head *fe_bh,
 117				    struct buffer_head *bg_bh,
 118				    struct buffer_head *prev_bg_bh,
 119				    u16 chain);
 120static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
 121						     u32 wanted);
 122static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
 123						   u64 bg_blkno,
 124						   u16 bg_bit_off);
 125static inline void ocfs2_block_to_cluster_group(struct inode *inode,
 126						u64 data_blkno,
 127						u64 *bg_blkno,
 128						u16 *bg_bit_off);
 129static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
 130					     u32 bits_wanted, u64 max_block,
 131					     int flags,
 132					     struct ocfs2_alloc_context **ac);
 133
 134void ocfs2_free_ac_resource(struct ocfs2_alloc_context *ac)
 135{
 136	struct inode *inode = ac->ac_inode;
 137
 138	if (inode) {
 139		if (ac->ac_which != OCFS2_AC_USE_LOCAL)
 140			ocfs2_inode_unlock(inode, 1);
 141
 142		inode_unlock(inode);
 143
 144		iput(inode);
 145		ac->ac_inode = NULL;
 146	}
 147	brelse(ac->ac_bh);
 148	ac->ac_bh = NULL;
 149	ac->ac_resv = NULL;
 150	kfree(ac->ac_find_loc_priv);
 151	ac->ac_find_loc_priv = NULL;
 152}
 153
 154void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
 155{
 156	ocfs2_free_ac_resource(ac);
 157	kfree(ac);
 158}
 159
 160static u32 ocfs2_bits_per_group(struct ocfs2_chain_list *cl)
 161{
 162	return (u32)le16_to_cpu(cl->cl_cpg) * (u32)le16_to_cpu(cl->cl_bpc);
 163}
 164
 165#define do_error(fmt, ...)						\
 166do {									\
 167	if (resize)							\
 168		mlog(ML_ERROR, fmt, ##__VA_ARGS__);			\
 169	else								\
 170		return ocfs2_error(sb, fmt, ##__VA_ARGS__);		\
 171} while (0)
 172
 173static int ocfs2_validate_gd_self(struct super_block *sb,
 174				  struct buffer_head *bh,
 175				  int resize)
 176{
 177	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 178
 179	if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
 180		do_error("Group descriptor #%llu has bad signature %.*s\n",
 181			 (unsigned long long)bh->b_blocknr, 7,
 182			 gd->bg_signature);
 183	}
 184
 185	if (le64_to_cpu(gd->bg_blkno) != bh->b_blocknr) {
 186		do_error("Group descriptor #%llu has an invalid bg_blkno of %llu\n",
 187			 (unsigned long long)bh->b_blocknr,
 188			 (unsigned long long)le64_to_cpu(gd->bg_blkno));
 189	}
 190
 191	if (le32_to_cpu(gd->bg_generation) != OCFS2_SB(sb)->fs_generation) {
 192		do_error("Group descriptor #%llu has an invalid fs_generation of #%u\n",
 193			 (unsigned long long)bh->b_blocknr,
 194			 le32_to_cpu(gd->bg_generation));
 195	}
 196
 197	if (le16_to_cpu(gd->bg_free_bits_count) > le16_to_cpu(gd->bg_bits)) {
 198		do_error("Group descriptor #%llu has bit count %u but claims that %u are free\n",
 199			 (unsigned long long)bh->b_blocknr,
 200			 le16_to_cpu(gd->bg_bits),
 201			 le16_to_cpu(gd->bg_free_bits_count));
 202	}
 203
 204	if (le16_to_cpu(gd->bg_bits) > (8 * le16_to_cpu(gd->bg_size))) {
 205		do_error("Group descriptor #%llu has bit count %u but max bitmap bits of %u\n",
 206			 (unsigned long long)bh->b_blocknr,
 207			 le16_to_cpu(gd->bg_bits),
 208			 8 * le16_to_cpu(gd->bg_size));
 209	}
 210
 211	return 0;
 212}
 213
 214static int ocfs2_validate_gd_parent(struct super_block *sb,
 215				    struct ocfs2_dinode *di,
 216				    struct buffer_head *bh,
 217				    int resize)
 218{
 219	unsigned int max_bits;
 220	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 221
 222	if (di->i_blkno != gd->bg_parent_dinode) {
 223		do_error("Group descriptor #%llu has bad parent pointer (%llu, expected %llu)\n",
 224			 (unsigned long long)bh->b_blocknr,
 225			 (unsigned long long)le64_to_cpu(gd->bg_parent_dinode),
 226			 (unsigned long long)le64_to_cpu(di->i_blkno));
 227	}
 228
 229	max_bits = le16_to_cpu(di->id2.i_chain.cl_cpg) * le16_to_cpu(di->id2.i_chain.cl_bpc);
 230	if (le16_to_cpu(gd->bg_bits) > max_bits) {
 231		do_error("Group descriptor #%llu has bit count of %u\n",
 232			 (unsigned long long)bh->b_blocknr,
 233			 le16_to_cpu(gd->bg_bits));
 234	}
 235
 236	/* In resize, we may meet the case bg_chain == cl_next_free_rec. */
 237	if ((le16_to_cpu(gd->bg_chain) >
 238	     le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) ||
 239	    ((le16_to_cpu(gd->bg_chain) ==
 240	     le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) && !resize)) {
 241		do_error("Group descriptor #%llu has bad chain %u\n",
 242			 (unsigned long long)bh->b_blocknr,
 243			 le16_to_cpu(gd->bg_chain));
 244	}
 245
 246	return 0;
 247}
 248
 249#undef do_error
 250
 251/*
 252 * This version only prints errors.  It does not fail the filesystem, and
 253 * exists only for resize.
 254 */
 255int ocfs2_check_group_descriptor(struct super_block *sb,
 256				 struct ocfs2_dinode *di,
 257				 struct buffer_head *bh)
 258{
 259	int rc;
 260	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 261
 262	BUG_ON(!buffer_uptodate(bh));
 263
 264	/*
 265	 * If the ecc fails, we return the error but otherwise
 266	 * leave the filesystem running.  We know any error is
 267	 * local to this block.
 268	 */
 269	rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
 270	if (rc) {
 271		mlog(ML_ERROR,
 272		     "Checksum failed for group descriptor %llu\n",
 273		     (unsigned long long)bh->b_blocknr);
 274	} else
 275		rc = ocfs2_validate_gd_self(sb, bh, 1);
 276	if (!rc)
 277		rc = ocfs2_validate_gd_parent(sb, di, bh, 1);
 278
 279	return rc;
 280}
 281
 282static int ocfs2_validate_group_descriptor(struct super_block *sb,
 283					   struct buffer_head *bh)
 284{
 285	int rc;
 286	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 287
 288	trace_ocfs2_validate_group_descriptor(
 289					(unsigned long long)bh->b_blocknr);
 290
 291	BUG_ON(!buffer_uptodate(bh));
 292
 293	/*
 294	 * If the ecc fails, we return the error but otherwise
 295	 * leave the filesystem running.  We know any error is
 296	 * local to this block.
 297	 */
 298	rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
 299	if (rc)
 300		return rc;
 301
 302	/*
 303	 * Errors after here are fatal.
 304	 */
 305
 306	return ocfs2_validate_gd_self(sb, bh, 0);
 307}
 308
 309int ocfs2_read_group_descriptor(struct inode *inode, struct ocfs2_dinode *di,
 310				u64 gd_blkno, struct buffer_head **bh)
 311{
 312	int rc;
 313	struct buffer_head *tmp = *bh;
 314
 315	rc = ocfs2_read_block(INODE_CACHE(inode), gd_blkno, &tmp,
 316			      ocfs2_validate_group_descriptor);
 317	if (rc)
 318		goto out;
 319
 320	rc = ocfs2_validate_gd_parent(inode->i_sb, di, tmp, 0);
 321	if (rc) {
 322		brelse(tmp);
 323		goto out;
 324	}
 325
 326	/* If ocfs2_read_block() got us a new bh, pass it up. */
 327	if (!*bh)
 328		*bh = tmp;
 329
 330out:
 331	return rc;
 332}
 333
 334static void ocfs2_bg_discontig_add_extent(struct ocfs2_super *osb,
 335					  struct ocfs2_group_desc *bg,
 336					  struct ocfs2_chain_list *cl,
 337					  u64 p_blkno, unsigned int clusters)
 338{
 339	struct ocfs2_extent_list *el = &bg->bg_list;
 340	struct ocfs2_extent_rec *rec;
 341
 342	BUG_ON(!ocfs2_supports_discontig_bg(osb));
 343	if (!el->l_next_free_rec)
 344		el->l_count = cpu_to_le16(ocfs2_extent_recs_per_gd(osb->sb));
 345	rec = &el->l_recs[le16_to_cpu(el->l_next_free_rec)];
 346	rec->e_blkno = cpu_to_le64(p_blkno);
 347	rec->e_cpos = cpu_to_le32(le16_to_cpu(bg->bg_bits) /
 348				  le16_to_cpu(cl->cl_bpc));
 349	rec->e_leaf_clusters = cpu_to_le16(clusters);
 350	le16_add_cpu(&bg->bg_bits, clusters * le16_to_cpu(cl->cl_bpc));
 351	le16_add_cpu(&bg->bg_free_bits_count,
 352		     clusters * le16_to_cpu(cl->cl_bpc));
 353	le16_add_cpu(&el->l_next_free_rec, 1);
 354}
 355
 356static int ocfs2_block_group_fill(handle_t *handle,
 357				  struct inode *alloc_inode,
 358				  struct buffer_head *bg_bh,
 359				  u64 group_blkno,
 360				  unsigned int group_clusters,
 361				  u16 my_chain,
 362				  struct ocfs2_chain_list *cl)
 363{
 364	int status = 0;
 365	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 366	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 367	struct super_block * sb = alloc_inode->i_sb;
 368
 369	if (((unsigned long long) bg_bh->b_blocknr) != group_blkno) {
 370		status = ocfs2_error(alloc_inode->i_sb,
 371				     "group block (%llu) != b_blocknr (%llu)\n",
 372				     (unsigned long long)group_blkno,
 373				     (unsigned long long) bg_bh->b_blocknr);
 374		goto bail;
 375	}
 376
 377	status = ocfs2_journal_access_gd(handle,
 378					 INODE_CACHE(alloc_inode),
 379					 bg_bh,
 380					 OCFS2_JOURNAL_ACCESS_CREATE);
 381	if (status < 0) {
 382		mlog_errno(status);
 383		goto bail;
 384	}
 385
 386	memset(bg, 0, sb->s_blocksize);
 387	strcpy(bg->bg_signature, OCFS2_GROUP_DESC_SIGNATURE);
 388	bg->bg_generation = cpu_to_le32(osb->fs_generation);
 389	bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb, 1,
 390						osb->s_feature_incompat));
 391	bg->bg_chain = cpu_to_le16(my_chain);
 392	bg->bg_next_group = cl->cl_recs[my_chain].c_blkno;
 393	bg->bg_parent_dinode = cpu_to_le64(OCFS2_I(alloc_inode)->ip_blkno);
 394	bg->bg_blkno = cpu_to_le64(group_blkno);
 395	if (group_clusters == le16_to_cpu(cl->cl_cpg))
 396		bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
 397	else
 398		ocfs2_bg_discontig_add_extent(osb, bg, cl, group_blkno,
 399					      group_clusters);
 400
 401	/* set the 1st bit in the bitmap to account for the descriptor block */
 402	ocfs2_set_bit(0, (unsigned long *)bg->bg_bitmap);
 403	bg->bg_free_bits_count = cpu_to_le16(le16_to_cpu(bg->bg_bits) - 1);
 404
 405	ocfs2_journal_dirty(handle, bg_bh);
 406
 407	/* There is no need to zero out or otherwise initialize the
 408	 * other blocks in a group - All valid FS metadata in a block
 409	 * group stores the superblock fs_generation value at
 410	 * allocation time. */
 411
 412bail:
 413	if (status)
 414		mlog_errno(status);
 415	return status;
 416}
 417
 418static inline u16 ocfs2_find_smallest_chain(struct ocfs2_chain_list *cl)
 419{
 420	u16 curr, best;
 421
 422	best = curr = 0;
 423	while (curr < le16_to_cpu(cl->cl_count)) {
 424		if (le32_to_cpu(cl->cl_recs[best].c_total) >
 425		    le32_to_cpu(cl->cl_recs[curr].c_total))
 426			best = curr;
 427		curr++;
 428	}
 429	return best;
 430}
 431
 432static struct buffer_head *
 433ocfs2_block_group_alloc_contig(struct ocfs2_super *osb, handle_t *handle,
 434			       struct inode *alloc_inode,
 435			       struct ocfs2_alloc_context *ac,
 436			       struct ocfs2_chain_list *cl)
 437{
 438	int status;
 439	u32 bit_off, num_bits;
 440	u64 bg_blkno;
 441	struct buffer_head *bg_bh;
 442	unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
 443
 444	status = ocfs2_claim_clusters(handle, ac,
 445				      le16_to_cpu(cl->cl_cpg), &bit_off,
 446				      &num_bits);
 447	if (status < 0) {
 448		if (status != -ENOSPC)
 449			mlog_errno(status);
 450		goto bail;
 451	}
 452
 453	/* setup the group */
 454	bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 455	trace_ocfs2_block_group_alloc_contig(
 456	     (unsigned long long)bg_blkno, alloc_rec);
 457
 458	bg_bh = sb_getblk(osb->sb, bg_blkno);
 459	if (!bg_bh) {
 460		status = -ENOMEM;
 461		mlog_errno(status);
 462		goto bail;
 463	}
 464	ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
 465
 466	status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
 467					bg_blkno, num_bits, alloc_rec, cl);
 468	if (status < 0) {
 469		brelse(bg_bh);
 470		mlog_errno(status);
 471	}
 472
 473bail:
 474	return status ? ERR_PTR(status) : bg_bh;
 475}
 476
 477static int ocfs2_block_group_claim_bits(struct ocfs2_super *osb,
 478					handle_t *handle,
 479					struct ocfs2_alloc_context *ac,
 480					unsigned int min_bits,
 481					u32 *bit_off, u32 *num_bits)
 482{
 483	int status = 0;
 484
 485	while (min_bits) {
 486		status = ocfs2_claim_clusters(handle, ac, min_bits,
 487					      bit_off, num_bits);
 488		if (status != -ENOSPC)
 489			break;
 490
 491		min_bits >>= 1;
 492	}
 493
 494	return status;
 495}
 496
 497static int ocfs2_block_group_grow_discontig(handle_t *handle,
 498					    struct inode *alloc_inode,
 499					    struct buffer_head *bg_bh,
 500					    struct ocfs2_alloc_context *ac,
 501					    struct ocfs2_chain_list *cl,
 502					    unsigned int min_bits)
 503{
 504	int status;
 505	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 506	struct ocfs2_group_desc *bg =
 507		(struct ocfs2_group_desc *)bg_bh->b_data;
 508	unsigned int needed = le16_to_cpu(cl->cl_cpg) -
 509			 le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
 510	u32 p_cpos, clusters;
 511	u64 p_blkno;
 512	struct ocfs2_extent_list *el = &bg->bg_list;
 513
 514	status = ocfs2_journal_access_gd(handle,
 515					 INODE_CACHE(alloc_inode),
 516					 bg_bh,
 517					 OCFS2_JOURNAL_ACCESS_CREATE);
 518	if (status < 0) {
 519		mlog_errno(status);
 520		goto bail;
 521	}
 522
 523	while ((needed > 0) && (le16_to_cpu(el->l_next_free_rec) <
 524				le16_to_cpu(el->l_count))) {
 525		if (min_bits > needed)
 526			min_bits = needed;
 527		status = ocfs2_block_group_claim_bits(osb, handle, ac,
 528						      min_bits, &p_cpos,
 529						      &clusters);
 530		if (status < 0) {
 531			if (status != -ENOSPC)
 532				mlog_errno(status);
 533			goto bail;
 534		}
 535		p_blkno = ocfs2_clusters_to_blocks(osb->sb, p_cpos);
 536		ocfs2_bg_discontig_add_extent(osb, bg, cl, p_blkno,
 537					      clusters);
 538
 539		min_bits = clusters;
 540		needed = le16_to_cpu(cl->cl_cpg) -
 541			 le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
 542	}
 543
 544	if (needed > 0) {
 545		/*
 546		 * We have used up all the extent rec but can't fill up
 547		 * the cpg. So bail out.
 548		 */
 549		status = -ENOSPC;
 550		goto bail;
 551	}
 552
 553	ocfs2_journal_dirty(handle, bg_bh);
 554
 555bail:
 556	return status;
 557}
 558
 559static void ocfs2_bg_alloc_cleanup(handle_t *handle,
 560				   struct ocfs2_alloc_context *cluster_ac,
 561				   struct inode *alloc_inode,
 562				   struct buffer_head *bg_bh)
 563{
 564	int i, ret;
 565	struct ocfs2_group_desc *bg;
 566	struct ocfs2_extent_list *el;
 567	struct ocfs2_extent_rec *rec;
 568
 569	if (!bg_bh)
 570		return;
 571
 572	bg = (struct ocfs2_group_desc *)bg_bh->b_data;
 573	el = &bg->bg_list;
 574	for (i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
 575		rec = &el->l_recs[i];
 576		ret = ocfs2_free_clusters(handle, cluster_ac->ac_inode,
 577					  cluster_ac->ac_bh,
 578					  le64_to_cpu(rec->e_blkno),
 579					  le16_to_cpu(rec->e_leaf_clusters));
 580		if (ret)
 581			mlog_errno(ret);
 582		/* Try all the clusters to free */
 583	}
 584
 585	ocfs2_remove_from_cache(INODE_CACHE(alloc_inode), bg_bh);
 586	brelse(bg_bh);
 587}
 588
 589static struct buffer_head *
 590ocfs2_block_group_alloc_discontig(handle_t *handle,
 591				  struct inode *alloc_inode,
 592				  struct ocfs2_alloc_context *ac,
 593				  struct ocfs2_chain_list *cl)
 594{
 595	int status;
 596	u32 bit_off, num_bits;
 597	u64 bg_blkno;
 598	unsigned int min_bits = le16_to_cpu(cl->cl_cpg) >> 1;
 599	struct buffer_head *bg_bh = NULL;
 600	unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
 601	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 602
 603	if (!ocfs2_supports_discontig_bg(osb)) {
 604		status = -ENOSPC;
 605		goto bail;
 606	}
 607
 608	status = ocfs2_extend_trans(handle,
 609				    ocfs2_calc_bg_discontig_credits(osb->sb));
 610	if (status) {
 611		mlog_errno(status);
 612		goto bail;
 613	}
 614
 615	/*
 616	 * We're going to be grabbing from multiple cluster groups.
 617	 * We don't have enough credits to relink them all, and the
 618	 * cluster groups will be staying in cache for the duration of
 619	 * this operation.
 620	 */
 621	ac->ac_disable_chain_relink = 1;
 622
 623	/* Claim the first region */
 624	status = ocfs2_block_group_claim_bits(osb, handle, ac, min_bits,
 625					      &bit_off, &num_bits);
 626	if (status < 0) {
 627		if (status != -ENOSPC)
 628			mlog_errno(status);
 629		goto bail;
 630	}
 631	min_bits = num_bits;
 632
 633	/* setup the group */
 634	bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 635	trace_ocfs2_block_group_alloc_discontig(
 636				(unsigned long long)bg_blkno, alloc_rec);
 637
 638	bg_bh = sb_getblk(osb->sb, bg_blkno);
 639	if (!bg_bh) {
 640		status = -ENOMEM;
 641		mlog_errno(status);
 642		goto bail;
 643	}
 644	ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
 645
 646	status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
 647					bg_blkno, num_bits, alloc_rec, cl);
 648	if (status < 0) {
 649		mlog_errno(status);
 650		goto bail;
 651	}
 652
 653	status = ocfs2_block_group_grow_discontig(handle, alloc_inode,
 654						  bg_bh, ac, cl, min_bits);
 655	if (status)
 656		mlog_errno(status);
 657
 658bail:
 659	if (status)
 660		ocfs2_bg_alloc_cleanup(handle, ac, alloc_inode, bg_bh);
 661	return status ? ERR_PTR(status) : bg_bh;
 662}
 663
 664/*
 665 * We expect the block group allocator to already be locked.
 666 */
 667static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
 668				   struct inode *alloc_inode,
 669				   struct buffer_head *bh,
 670				   u64 max_block,
 671				   u64 *last_alloc_group,
 672				   int flags)
 673{
 674	int status, credits;
 675	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) bh->b_data;
 676	struct ocfs2_chain_list *cl;
 677	struct ocfs2_alloc_context *ac = NULL;
 678	handle_t *handle = NULL;
 679	u16 alloc_rec;
 680	struct buffer_head *bg_bh = NULL;
 681	struct ocfs2_group_desc *bg;
 682
 683	BUG_ON(ocfs2_is_cluster_bitmap(alloc_inode));
 684
 685	cl = &fe->id2.i_chain;
 686	status = ocfs2_reserve_clusters_with_limit(osb,
 687						   le16_to_cpu(cl->cl_cpg),
 688						   max_block, flags, &ac);
 689	if (status < 0) {
 690		if (status != -ENOSPC)
 691			mlog_errno(status);
 692		goto bail;
 693	}
 694
 695	credits = ocfs2_calc_group_alloc_credits(osb->sb,
 696						 le16_to_cpu(cl->cl_cpg));
 697	handle = ocfs2_start_trans(osb, credits);
 698	if (IS_ERR(handle)) {
 699		status = PTR_ERR(handle);
 700		handle = NULL;
 701		mlog_errno(status);
 702		goto bail;
 703	}
 704
 705	if (last_alloc_group && *last_alloc_group != 0) {
 706		trace_ocfs2_block_group_alloc(
 707				(unsigned long long)*last_alloc_group);
 708		ac->ac_last_group = *last_alloc_group;
 709	}
 710
 711	bg_bh = ocfs2_block_group_alloc_contig(osb, handle, alloc_inode,
 712					       ac, cl);
 713	if (IS_ERR(bg_bh) && (PTR_ERR(bg_bh) == -ENOSPC))
 714		bg_bh = ocfs2_block_group_alloc_discontig(handle,
 715							  alloc_inode,
 716							  ac, cl);
 717	if (IS_ERR(bg_bh)) {
 718		status = PTR_ERR(bg_bh);
 719		bg_bh = NULL;
 720		if (status != -ENOSPC)
 721			mlog_errno(status);
 722		goto bail;
 723	}
 724	bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 725
 726	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
 727					 bh, OCFS2_JOURNAL_ACCESS_WRITE);
 728	if (status < 0) {
 729		mlog_errno(status);
 730		goto bail;
 731	}
 732
 733	alloc_rec = le16_to_cpu(bg->bg_chain);
 734	le32_add_cpu(&cl->cl_recs[alloc_rec].c_free,
 735		     le16_to_cpu(bg->bg_free_bits_count));
 736	le32_add_cpu(&cl->cl_recs[alloc_rec].c_total,
 737		     le16_to_cpu(bg->bg_bits));
 738	cl->cl_recs[alloc_rec].c_blkno = bg->bg_blkno;
 739	if (le16_to_cpu(cl->cl_next_free_rec) < le16_to_cpu(cl->cl_count))
 740		le16_add_cpu(&cl->cl_next_free_rec, 1);
 741
 742	le32_add_cpu(&fe->id1.bitmap1.i_used, le16_to_cpu(bg->bg_bits) -
 743					le16_to_cpu(bg->bg_free_bits_count));
 744	le32_add_cpu(&fe->id1.bitmap1.i_total, le16_to_cpu(bg->bg_bits));
 745	le32_add_cpu(&fe->i_clusters, le16_to_cpu(cl->cl_cpg));
 746
 747	ocfs2_journal_dirty(handle, bh);
 748
 749	spin_lock(&OCFS2_I(alloc_inode)->ip_lock);
 750	OCFS2_I(alloc_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
 751	fe->i_size = cpu_to_le64(ocfs2_clusters_to_bytes(alloc_inode->i_sb,
 752					     le32_to_cpu(fe->i_clusters)));
 753	spin_unlock(&OCFS2_I(alloc_inode)->ip_lock);
 754	i_size_write(alloc_inode, le64_to_cpu(fe->i_size));
 755	alloc_inode->i_blocks = ocfs2_inode_sector_count(alloc_inode);
 756	ocfs2_update_inode_fsync_trans(handle, alloc_inode, 0);
 757
 758	status = 0;
 759
 760	/* save the new last alloc group so that the caller can cache it. */
 761	if (last_alloc_group)
 762		*last_alloc_group = ac->ac_last_group;
 763
 764bail:
 765	if (handle)
 766		ocfs2_commit_trans(osb, handle);
 767
 768	if (ac)
 769		ocfs2_free_alloc_context(ac);
 770
 771	brelse(bg_bh);
 772
 773	if (status)
 774		mlog_errno(status);
 775	return status;
 776}
 777
 778static int ocfs2_reserve_suballoc_bits(struct ocfs2_super *osb,
 779				       struct ocfs2_alloc_context *ac,
 780				       int type,
 781				       u32 slot,
 782				       u64 *last_alloc_group,
 783				       int flags)
 784{
 785	int status;
 786	u32 bits_wanted = ac->ac_bits_wanted;
 787	struct inode *alloc_inode;
 788	struct buffer_head *bh = NULL;
 789	struct ocfs2_dinode *fe;
 790	u32 free_bits;
 791
 792	alloc_inode = ocfs2_get_system_file_inode(osb, type, slot);
 793	if (!alloc_inode) {
 794		mlog_errno(-EINVAL);
 795		return -EINVAL;
 796	}
 797
 798	inode_lock(alloc_inode);
 799
 800	status = ocfs2_inode_lock(alloc_inode, &bh, 1);
 801	if (status < 0) {
 802		inode_unlock(alloc_inode);
 803		iput(alloc_inode);
 804
 805		mlog_errno(status);
 806		return status;
 807	}
 808
 809	ac->ac_inode = alloc_inode;
 810	ac->ac_alloc_slot = slot;
 811
 812	fe = (struct ocfs2_dinode *) bh->b_data;
 813
 814	/* The bh was validated by the inode read inside
 815	 * ocfs2_inode_lock().  Any corruption is a code bug. */
 816	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
 817
 818	if (!(fe->i_flags & cpu_to_le32(OCFS2_CHAIN_FL))) {
 819		status = ocfs2_error(alloc_inode->i_sb,
 820				     "Invalid chain allocator %llu\n",
 821				     (unsigned long long)le64_to_cpu(fe->i_blkno));
 822		goto bail;
 823	}
 824
 825	free_bits = le32_to_cpu(fe->id1.bitmap1.i_total) -
 826		le32_to_cpu(fe->id1.bitmap1.i_used);
 827
 828	if (bits_wanted > free_bits) {
 829		/* cluster bitmap never grows */
 830		if (ocfs2_is_cluster_bitmap(alloc_inode)) {
 831			trace_ocfs2_reserve_suballoc_bits_nospc(bits_wanted,
 832								free_bits);
 833			status = -ENOSPC;
 834			goto bail;
 835		}
 836
 837		if (!(flags & ALLOC_NEW_GROUP)) {
 838			trace_ocfs2_reserve_suballoc_bits_no_new_group(
 839						slot, bits_wanted, free_bits);
 840			status = -ENOSPC;
 841			goto bail;
 842		}
 843
 844		status = ocfs2_block_group_alloc(osb, alloc_inode, bh,
 845						 ac->ac_max_block,
 846						 last_alloc_group, flags);
 847		if (status < 0) {
 848			if (status != -ENOSPC)
 849				mlog_errno(status);
 850			goto bail;
 851		}
 852		atomic_inc(&osb->alloc_stats.bg_extends);
 853
 854		/* You should never ask for this much metadata */
 855		BUG_ON(bits_wanted >
 856		       (le32_to_cpu(fe->id1.bitmap1.i_total)
 857			- le32_to_cpu(fe->id1.bitmap1.i_used)));
 858	}
 859
 860	get_bh(bh);
 861	ac->ac_bh = bh;
 862bail:
 863	brelse(bh);
 864
 865	if (status)
 866		mlog_errno(status);
 867	return status;
 868}
 869
 870static void ocfs2_init_inode_steal_slot(struct ocfs2_super *osb)
 871{
 872	spin_lock(&osb->osb_lock);
 873	osb->s_inode_steal_slot = OCFS2_INVALID_SLOT;
 874	spin_unlock(&osb->osb_lock);
 875	atomic_set(&osb->s_num_inodes_stolen, 0);
 876}
 877
 878static void ocfs2_init_meta_steal_slot(struct ocfs2_super *osb)
 879{
 880	spin_lock(&osb->osb_lock);
 881	osb->s_meta_steal_slot = OCFS2_INVALID_SLOT;
 882	spin_unlock(&osb->osb_lock);
 883	atomic_set(&osb->s_num_meta_stolen, 0);
 884}
 885
 886void ocfs2_init_steal_slots(struct ocfs2_super *osb)
 887{
 888	ocfs2_init_inode_steal_slot(osb);
 889	ocfs2_init_meta_steal_slot(osb);
 890}
 891
 892static void __ocfs2_set_steal_slot(struct ocfs2_super *osb, int slot, int type)
 893{
 894	spin_lock(&osb->osb_lock);
 895	if (type == INODE_ALLOC_SYSTEM_INODE)
 896		osb->s_inode_steal_slot = slot;
 897	else if (type == EXTENT_ALLOC_SYSTEM_INODE)
 898		osb->s_meta_steal_slot = slot;
 899	spin_unlock(&osb->osb_lock);
 900}
 901
 902static int __ocfs2_get_steal_slot(struct ocfs2_super *osb, int type)
 903{
 904	int slot = OCFS2_INVALID_SLOT;
 905
 906	spin_lock(&osb->osb_lock);
 907	if (type == INODE_ALLOC_SYSTEM_INODE)
 908		slot = osb->s_inode_steal_slot;
 909	else if (type == EXTENT_ALLOC_SYSTEM_INODE)
 910		slot = osb->s_meta_steal_slot;
 911	spin_unlock(&osb->osb_lock);
 912
 913	return slot;
 914}
 915
 916static int ocfs2_get_inode_steal_slot(struct ocfs2_super *osb)
 917{
 918	return __ocfs2_get_steal_slot(osb, INODE_ALLOC_SYSTEM_INODE);
 919}
 920
 921static int ocfs2_get_meta_steal_slot(struct ocfs2_super *osb)
 922{
 923	return __ocfs2_get_steal_slot(osb, EXTENT_ALLOC_SYSTEM_INODE);
 924}
 925
 926static int ocfs2_steal_resource(struct ocfs2_super *osb,
 927				struct ocfs2_alloc_context *ac,
 928				int type)
 929{
 930	int i, status = -ENOSPC;
 931	int slot = __ocfs2_get_steal_slot(osb, type);
 932
 933	/* Start to steal resource from the first slot after ours. */
 934	if (slot == OCFS2_INVALID_SLOT)
 935		slot = osb->slot_num + 1;
 936
 937	for (i = 0; i < osb->max_slots; i++, slot++) {
 938		if (slot == osb->max_slots)
 939			slot = 0;
 940
 941		if (slot == osb->slot_num)
 942			continue;
 943
 944		status = ocfs2_reserve_suballoc_bits(osb, ac,
 945						     type,
 946						     (u32)slot, NULL,
 947						     NOT_ALLOC_NEW_GROUP);
 948		if (status >= 0) {
 949			__ocfs2_set_steal_slot(osb, slot, type);
 950			break;
 951		}
 952
 953		ocfs2_free_ac_resource(ac);
 954	}
 955
 956	return status;
 957}
 958
 959static int ocfs2_steal_inode(struct ocfs2_super *osb,
 960			     struct ocfs2_alloc_context *ac)
 961{
 962	return ocfs2_steal_resource(osb, ac, INODE_ALLOC_SYSTEM_INODE);
 963}
 964
 965static int ocfs2_steal_meta(struct ocfs2_super *osb,
 966			    struct ocfs2_alloc_context *ac)
 967{
 968	return ocfs2_steal_resource(osb, ac, EXTENT_ALLOC_SYSTEM_INODE);
 969}
 970
 971int ocfs2_reserve_new_metadata_blocks(struct ocfs2_super *osb,
 972				      int blocks,
 973				      struct ocfs2_alloc_context **ac)
 974{
 975	int status;
 976	int slot = ocfs2_get_meta_steal_slot(osb);
 977
 978	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 979	if (!(*ac)) {
 980		status = -ENOMEM;
 981		mlog_errno(status);
 982		goto bail;
 983	}
 984
 985	(*ac)->ac_bits_wanted = blocks;
 986	(*ac)->ac_which = OCFS2_AC_USE_META;
 987	(*ac)->ac_group_search = ocfs2_block_group_search;
 988
 989	if (slot != OCFS2_INVALID_SLOT &&
 990		atomic_read(&osb->s_num_meta_stolen) < OCFS2_MAX_TO_STEAL)
 991		goto extent_steal;
 992
 993	atomic_set(&osb->s_num_meta_stolen, 0);
 994	status = ocfs2_reserve_suballoc_bits(osb, (*ac),
 995					     EXTENT_ALLOC_SYSTEM_INODE,
 996					     (u32)osb->slot_num, NULL,
 997					     ALLOC_GROUPS_FROM_GLOBAL|ALLOC_NEW_GROUP);
 998
 999
1000	if (status >= 0) {
1001		status = 0;
1002		if (slot != OCFS2_INVALID_SLOT)
1003			ocfs2_init_meta_steal_slot(osb);
1004		goto bail;
1005	} else if (status < 0 && status != -ENOSPC) {
1006		mlog_errno(status);
1007		goto bail;
1008	}
1009
1010	ocfs2_free_ac_resource(*ac);
1011
1012extent_steal:
1013	status = ocfs2_steal_meta(osb, *ac);
1014	atomic_inc(&osb->s_num_meta_stolen);
1015	if (status < 0) {
1016		if (status != -ENOSPC)
1017			mlog_errno(status);
1018		goto bail;
1019	}
1020
1021	status = 0;
1022bail:
1023	if ((status < 0) && *ac) {
1024		ocfs2_free_alloc_context(*ac);
1025		*ac = NULL;
1026	}
1027
1028	if (status)
1029		mlog_errno(status);
1030	return status;
1031}
1032
1033int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
1034			       struct ocfs2_extent_list *root_el,
1035			       struct ocfs2_alloc_context **ac)
1036{
1037	return ocfs2_reserve_new_metadata_blocks(osb,
1038					ocfs2_extend_meta_needed(root_el),
1039					ac);
1040}
1041
1042int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
1043			    struct ocfs2_alloc_context **ac)
1044{
1045	int status;
1046	int slot = ocfs2_get_inode_steal_slot(osb);
1047	u64 alloc_group;
1048
1049	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1050	if (!(*ac)) {
1051		status = -ENOMEM;
1052		mlog_errno(status);
1053		goto bail;
1054	}
1055
1056	(*ac)->ac_bits_wanted = 1;
1057	(*ac)->ac_which = OCFS2_AC_USE_INODE;
1058
1059	(*ac)->ac_group_search = ocfs2_block_group_search;
1060
1061	/*
1062	 * stat(2) can't handle i_ino > 32bits, so we tell the
1063	 * lower levels not to allocate us a block group past that
1064	 * limit.  The 'inode64' mount option avoids this behavior.
1065	 */
1066	if (!(osb->s_mount_opt & OCFS2_MOUNT_INODE64))
1067		(*ac)->ac_max_block = (u32)~0U;
1068
1069	/*
1070	 * slot is set when we successfully steal inode from other nodes.
1071	 * It is reset in 3 places:
1072	 * 1. when we flush the truncate log
1073	 * 2. when we complete local alloc recovery.
1074	 * 3. when we successfully allocate from our own slot.
1075	 * After it is set, we will go on stealing inodes until we find the
1076	 * need to check our slots to see whether there is some space for us.
1077	 */
1078	if (slot != OCFS2_INVALID_SLOT &&
1079	    atomic_read(&osb->s_num_inodes_stolen) < OCFS2_MAX_TO_STEAL)
1080		goto inode_steal;
1081
1082	atomic_set(&osb->s_num_inodes_stolen, 0);
1083	alloc_group = osb->osb_inode_alloc_group;
1084	status = ocfs2_reserve_suballoc_bits(osb, *ac,
1085					     INODE_ALLOC_SYSTEM_INODE,
1086					     (u32)osb->slot_num,
1087					     &alloc_group,
1088					     ALLOC_NEW_GROUP |
1089					     ALLOC_GROUPS_FROM_GLOBAL);
1090	if (status >= 0) {
1091		status = 0;
1092
1093		spin_lock(&osb->osb_lock);
1094		osb->osb_inode_alloc_group = alloc_group;
1095		spin_unlock(&osb->osb_lock);
1096		trace_ocfs2_reserve_new_inode_new_group(
1097			(unsigned long long)alloc_group);
1098
1099		/*
1100		 * Some inodes must be freed by us, so try to allocate
1101		 * from our own next time.
1102		 */
1103		if (slot != OCFS2_INVALID_SLOT)
1104			ocfs2_init_inode_steal_slot(osb);
1105		goto bail;
1106	} else if (status < 0 && status != -ENOSPC) {
1107		mlog_errno(status);
1108		goto bail;
1109	}
1110
1111	ocfs2_free_ac_resource(*ac);
1112
1113inode_steal:
1114	status = ocfs2_steal_inode(osb, *ac);
1115	atomic_inc(&osb->s_num_inodes_stolen);
1116	if (status < 0) {
1117		if (status != -ENOSPC)
1118			mlog_errno(status);
1119		goto bail;
1120	}
1121
1122	status = 0;
1123bail:
1124	if ((status < 0) && *ac) {
1125		ocfs2_free_alloc_context(*ac);
1126		*ac = NULL;
1127	}
1128
1129	if (status)
1130		mlog_errno(status);
1131	return status;
1132}
1133
1134/* local alloc code has to do the same thing, so rather than do this
1135 * twice.. */
1136int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
1137				      struct ocfs2_alloc_context *ac)
1138{
1139	int status;
1140
1141	ac->ac_which = OCFS2_AC_USE_MAIN;
1142	ac->ac_group_search = ocfs2_cluster_group_search;
1143
1144	status = ocfs2_reserve_suballoc_bits(osb, ac,
1145					     GLOBAL_BITMAP_SYSTEM_INODE,
1146					     OCFS2_INVALID_SLOT, NULL,
1147					     ALLOC_NEW_GROUP);
1148	if (status < 0 && status != -ENOSPC)
1149		mlog_errno(status);
1150
1151	return status;
1152}
1153
1154/* Callers don't need to care which bitmap (local alloc or main) to
1155 * use so we figure it out for them, but unfortunately this clutters
1156 * things a bit. */
1157static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
1158					     u32 bits_wanted, u64 max_block,
1159					     int flags,
1160					     struct ocfs2_alloc_context **ac)
1161{
1162	int status, ret = 0;
1163	int retried = 0;
1164
1165	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1166	if (!(*ac)) {
1167		status = -ENOMEM;
1168		mlog_errno(status);
1169		goto bail;
1170	}
1171
1172	(*ac)->ac_bits_wanted = bits_wanted;
1173	(*ac)->ac_max_block = max_block;
1174
1175	status = -ENOSPC;
1176	if (!(flags & ALLOC_GROUPS_FROM_GLOBAL) &&
1177	    ocfs2_alloc_should_use_local(osb, bits_wanted)) {
1178		status = ocfs2_reserve_local_alloc_bits(osb,
1179							bits_wanted,
1180							*ac);
1181		if ((status < 0) && (status != -ENOSPC)) {
1182			mlog_errno(status);
1183			goto bail;
1184		}
1185	}
1186
1187	if (status == -ENOSPC) {
1188retry:
1189		status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
1190		/* Retry if there is sufficient space cached in truncate log */
1191		if (status == -ENOSPC && !retried) {
1192			retried = 1;
1193			ocfs2_inode_unlock((*ac)->ac_inode, 1);
1194			inode_unlock((*ac)->ac_inode);
1195
1196			ret = ocfs2_try_to_free_truncate_log(osb, bits_wanted);
1197			if (ret == 1) {
1198				iput((*ac)->ac_inode);
1199				(*ac)->ac_inode = NULL;
1200				goto retry;
1201			}
1202
1203			if (ret < 0)
1204				mlog_errno(ret);
1205
1206			inode_lock((*ac)->ac_inode);
1207			ret = ocfs2_inode_lock((*ac)->ac_inode, NULL, 1);
1208			if (ret < 0) {
1209				mlog_errno(ret);
1210				inode_unlock((*ac)->ac_inode);
1211				iput((*ac)->ac_inode);
1212				(*ac)->ac_inode = NULL;
1213				goto bail;
1214			}
1215		}
1216		if (status < 0) {
1217			if (status != -ENOSPC)
1218				mlog_errno(status);
1219			goto bail;
1220		}
1221	}
1222
1223	status = 0;
1224bail:
1225	if ((status < 0) && *ac) {
1226		ocfs2_free_alloc_context(*ac);
1227		*ac = NULL;
1228	}
1229
1230	if (status)
1231		mlog_errno(status);
1232	return status;
1233}
1234
1235int ocfs2_reserve_clusters(struct ocfs2_super *osb,
1236			   u32 bits_wanted,
1237			   struct ocfs2_alloc_context **ac)
1238{
1239	return ocfs2_reserve_clusters_with_limit(osb, bits_wanted, 0,
1240						 ALLOC_NEW_GROUP, ac);
1241}
1242
1243/*
1244 * More or less lifted from ext3. I'll leave their description below:
1245 *
1246 * "For ext3 allocations, we must not reuse any blocks which are
1247 * allocated in the bitmap buffer's "last committed data" copy.  This
1248 * prevents deletes from freeing up the page for reuse until we have
1249 * committed the delete transaction.
1250 *
1251 * If we didn't do this, then deleting something and reallocating it as
1252 * data would allow the old block to be overwritten before the
1253 * transaction committed (because we force data to disk before commit).
1254 * This would lead to corruption if we crashed between overwriting the
1255 * data and committing the delete.
1256 *
1257 * @@@ We may want to make this allocation behaviour conditional on
1258 * data-writes at some point, and disable it for metadata allocations or
1259 * sync-data inodes."
1260 *
1261 * Note: OCFS2 already does this differently for metadata vs data
1262 * allocations, as those bitmaps are separate and undo access is never
1263 * called on a metadata group descriptor.
1264 */
1265static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
1266					 int nr)
1267{
1268	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1269	int ret;
1270
1271	if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
1272		return 0;
1273
1274	if (!buffer_jbd(bg_bh))
1275		return 1;
1276
1277	jbd_lock_bh_state(bg_bh);
1278	bg = (struct ocfs2_group_desc *) bh2jh(bg_bh)->b_committed_data;
1279	if (bg)
1280		ret = !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
1281	else
1282		ret = 1;
1283	jbd_unlock_bh_state(bg_bh);
1284
1285	return ret;
1286}
1287
1288static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
1289					     struct buffer_head *bg_bh,
1290					     unsigned int bits_wanted,
1291					     unsigned int total_bits,
1292					     struct ocfs2_suballoc_result *res)
1293{
1294	void *bitmap;
1295	u16 best_offset, best_size;
1296	int offset, start, found, status = 0;
1297	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1298
1299	/* Callers got this descriptor from
1300	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1301	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1302
1303	found = start = best_offset = best_size = 0;
1304	bitmap = bg->bg_bitmap;
1305
1306	while((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) != -1) {
1307		if (offset == total_bits)
1308			break;
1309
1310		if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
1311			/* We found a zero, but we can't use it as it
1312			 * hasn't been put to disk yet! */
1313			found = 0;
1314			start = offset + 1;
1315		} else if (offset == start) {
1316			/* we found a zero */
1317			found++;
1318			/* move start to the next bit to test */
1319			start++;
1320		} else {
1321			/* got a zero after some ones */
1322			found = 1;
1323			start = offset + 1;
1324		}
1325		if (found > best_size) {
1326			best_size = found;
1327			best_offset = start - found;
1328		}
1329		/* we got everything we needed */
1330		if (found == bits_wanted) {
1331			/* mlog(0, "Found it all!\n"); */
1332			break;
1333		}
1334	}
1335
1336	if (best_size) {
1337		res->sr_bit_offset = best_offset;
1338		res->sr_bits = best_size;
1339	} else {
1340		status = -ENOSPC;
1341		/* No error log here -- see the comment above
1342		 * ocfs2_test_bg_bit_allocatable */
1343	}
1344
1345	return status;
1346}
1347
1348int ocfs2_block_group_set_bits(handle_t *handle,
1349					     struct inode *alloc_inode,
1350					     struct ocfs2_group_desc *bg,
1351					     struct buffer_head *group_bh,
1352					     unsigned int bit_off,
1353					     unsigned int num_bits)
1354{
1355	int status;
1356	void *bitmap = bg->bg_bitmap;
1357	int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1358
1359	/* All callers get the descriptor via
1360	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1361	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1362	BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
1363
1364	trace_ocfs2_block_group_set_bits(bit_off, num_bits);
1365
1366	if (ocfs2_is_cluster_bitmap(alloc_inode))
1367		journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1368
1369	status = ocfs2_journal_access_gd(handle,
1370					 INODE_CACHE(alloc_inode),
1371					 group_bh,
1372					 journal_type);
1373	if (status < 0) {
1374		mlog_errno(status);
1375		goto bail;
1376	}
1377
1378	le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
1379	if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
1380		return ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit count %u but claims %u are freed. num_bits %d\n",
1381				   (unsigned long long)le64_to_cpu(bg->bg_blkno),
1382				   le16_to_cpu(bg->bg_bits),
1383				   le16_to_cpu(bg->bg_free_bits_count),
1384				   num_bits);
1385	}
1386	while(num_bits--)
1387		ocfs2_set_bit(bit_off++, bitmap);
1388
1389	ocfs2_journal_dirty(handle, group_bh);
1390
1391bail:
1392	return status;
1393}
1394
1395/* find the one with the most empty bits */
1396static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
1397{
1398	u16 curr, best;
1399
1400	BUG_ON(!cl->cl_next_free_rec);
1401
1402	best = curr = 0;
1403	while (curr < le16_to_cpu(cl->cl_next_free_rec)) {
1404		if (le32_to_cpu(cl->cl_recs[curr].c_free) >
1405		    le32_to_cpu(cl->cl_recs[best].c_free))
1406			best = curr;
1407		curr++;
1408	}
1409
1410	BUG_ON(best >= le16_to_cpu(cl->cl_next_free_rec));
1411	return best;
1412}
1413
1414static int ocfs2_relink_block_group(handle_t *handle,
1415				    struct inode *alloc_inode,
1416				    struct buffer_head *fe_bh,
1417				    struct buffer_head *bg_bh,
1418				    struct buffer_head *prev_bg_bh,
1419				    u16 chain)
1420{
1421	int status;
1422	/* there is a really tiny chance the journal calls could fail,
1423	 * but we wouldn't want inconsistent blocks in *any* case. */
1424	u64 bg_ptr, prev_bg_ptr;
1425	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
1426	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1427	struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
1428
1429	/* The caller got these descriptors from
1430	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1431	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1432	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(prev_bg));
1433
1434	trace_ocfs2_relink_block_group(
1435		(unsigned long long)le64_to_cpu(fe->i_blkno), chain,
1436		(unsigned long long)le64_to_cpu(bg->bg_blkno),
1437		(unsigned long long)le64_to_cpu(prev_bg->bg_blkno));
1438
1439	bg_ptr = le64_to_cpu(bg->bg_next_group);
1440	prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
1441
1442	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1443					 prev_bg_bh,
1444					 OCFS2_JOURNAL_ACCESS_WRITE);
1445	if (status < 0)
1446		goto out;
1447
1448	prev_bg->bg_next_group = bg->bg_next_group;
1449	ocfs2_journal_dirty(handle, prev_bg_bh);
1450
1451	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1452					 bg_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1453	if (status < 0)
1454		goto out_rollback_prev_bg;
1455
1456	bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
1457	ocfs2_journal_dirty(handle, bg_bh);
1458
1459	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
1460					 fe_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1461	if (status < 0)
1462		goto out_rollback_bg;
1463
1464	fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
1465	ocfs2_journal_dirty(handle, fe_bh);
1466
1467out:
1468	if (status < 0)
1469		mlog_errno(status);
1470	return status;
1471
1472out_rollback_bg:
1473	bg->bg_next_group = cpu_to_le64(bg_ptr);
1474out_rollback_prev_bg:
1475	prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
1476	goto out;
1477}
1478
1479static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
1480						     u32 wanted)
1481{
1482	return le16_to_cpu(bg->bg_free_bits_count) > wanted;
1483}
1484
1485/* return 0 on success, -ENOSPC to keep searching and any other < 0
1486 * value on error. */
1487static int ocfs2_cluster_group_search(struct inode *inode,
1488				      struct buffer_head *group_bh,
1489				      u32 bits_wanted, u32 min_bits,
1490				      u64 max_block,
1491				      struct ocfs2_suballoc_result *res)
1492{
1493	int search = -ENOSPC;
1494	int ret;
1495	u64 blkoff;
1496	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
1497	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1498	unsigned int max_bits, gd_cluster_off;
1499
1500	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1501
1502	if (gd->bg_free_bits_count) {
1503		max_bits = le16_to_cpu(gd->bg_bits);
1504
1505		/* Tail groups in cluster bitmaps which aren't cpg
1506		 * aligned are prone to partial extension by a failed
1507		 * fs resize. If the file system resize never got to
1508		 * update the dinode cluster count, then we don't want
1509		 * to trust any clusters past it, regardless of what
1510		 * the group descriptor says. */
1511		gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
1512							  le64_to_cpu(gd->bg_blkno));
1513		if ((gd_cluster_off + max_bits) >
1514		    OCFS2_I(inode)->ip_clusters) {
1515			max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
1516			trace_ocfs2_cluster_group_search_wrong_max_bits(
1517				(unsigned long long)le64_to_cpu(gd->bg_blkno),
1518				le16_to_cpu(gd->bg_bits),
1519				OCFS2_I(inode)->ip_clusters, max_bits);
1520		}
1521
1522		ret = ocfs2_block_group_find_clear_bits(osb,
1523							group_bh, bits_wanted,
1524							max_bits, res);
1525		if (ret)
1526			return ret;
1527
1528		if (max_block) {
1529			blkoff = ocfs2_clusters_to_blocks(inode->i_sb,
1530							  gd_cluster_off +
1531							  res->sr_bit_offset +
1532							  res->sr_bits);
1533			trace_ocfs2_cluster_group_search_max_block(
1534				(unsigned long long)blkoff,
1535				(unsigned long long)max_block);
1536			if (blkoff > max_block)
1537				return -ENOSPC;
1538		}
1539
1540		/* ocfs2_block_group_find_clear_bits() might
1541		 * return success, but we still want to return
1542		 * -ENOSPC unless it found the minimum number
1543		 * of bits. */
1544		if (min_bits <= res->sr_bits)
1545			search = 0; /* success */
1546		else if (res->sr_bits) {
1547			/*
1548			 * Don't show bits which we'll be returning
1549			 * for allocation to the local alloc bitmap.
1550			 */
1551			ocfs2_local_alloc_seen_free_bits(osb, res->sr_bits);
1552		}
1553	}
1554
1555	return search;
1556}
1557
1558static int ocfs2_block_group_search(struct inode *inode,
1559				    struct buffer_head *group_bh,
1560				    u32 bits_wanted, u32 min_bits,
1561				    u64 max_block,
1562				    struct ocfs2_suballoc_result *res)
1563{
1564	int ret = -ENOSPC;
1565	u64 blkoff;
1566	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
1567
1568	BUG_ON(min_bits != 1);
1569	BUG_ON(ocfs2_is_cluster_bitmap(inode));
1570
1571	if (bg->bg_free_bits_count) {
1572		ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1573							group_bh, bits_wanted,
1574							le16_to_cpu(bg->bg_bits),
1575							res);
1576		if (!ret && max_block) {
1577			blkoff = le64_to_cpu(bg->bg_blkno) +
1578				res->sr_bit_offset + res->sr_bits;
1579			trace_ocfs2_block_group_search_max_block(
1580				(unsigned long long)blkoff,
1581				(unsigned long long)max_block);
1582			if (blkoff > max_block)
1583				ret = -ENOSPC;
1584		}
1585	}
1586
1587	return ret;
1588}
1589
1590int ocfs2_alloc_dinode_update_counts(struct inode *inode,
1591				       handle_t *handle,
1592				       struct buffer_head *di_bh,
1593				       u32 num_bits,
1594				       u16 chain)
1595{
1596	int ret;
1597	u32 tmp_used;
1598	struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1599	struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &di->id2.i_chain;
1600
1601	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
1602				      OCFS2_JOURNAL_ACCESS_WRITE);
1603	if (ret < 0) {
1604		mlog_errno(ret);
1605		goto out;
1606	}
1607
1608	tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1609	di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
1610	le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
1611	ocfs2_journal_dirty(handle, di_bh);
1612
1613out:
1614	return ret;
1615}
1616
1617void ocfs2_rollback_alloc_dinode_counts(struct inode *inode,
1618				       struct buffer_head *di_bh,
1619				       u32 num_bits,
1620				       u16 chain)
1621{
1622	u32 tmp_used;
1623	struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1624	struct ocfs2_chain_list *cl;
1625
1626	cl = (struct ocfs2_chain_list *)&di->id2.i_chain;
1627	tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1628	di->id1.bitmap1.i_used = cpu_to_le32(tmp_used - num_bits);
1629	le32_add_cpu(&cl->cl_recs[chain].c_free, num_bits);
1630}
1631
1632static int ocfs2_bg_discontig_fix_by_rec(struct ocfs2_suballoc_result *res,
1633					 struct ocfs2_extent_rec *rec,
1634					 struct ocfs2_chain_list *cl)
1635{
1636	unsigned int bpc = le16_to_cpu(cl->cl_bpc);
1637	unsigned int bitoff = le32_to_cpu(rec->e_cpos) * bpc;
1638	unsigned int bitcount = le16_to_cpu(rec->e_leaf_clusters) * bpc;
1639
1640	if (res->sr_bit_offset < bitoff)
1641		return 0;
1642	if (res->sr_bit_offset >= (bitoff + bitcount))
1643		return 0;
1644	res->sr_blkno = le64_to_cpu(rec->e_blkno) +
1645		(res->sr_bit_offset - bitoff);
1646	if ((res->sr_bit_offset + res->sr_bits) > (bitoff + bitcount))
1647		res->sr_bits = (bitoff + bitcount) - res->sr_bit_offset;
1648	return 1;
1649}
1650
1651static void ocfs2_bg_discontig_fix_result(struct ocfs2_alloc_context *ac,
1652					  struct ocfs2_group_desc *bg,
1653					  struct ocfs2_suballoc_result *res)
1654{
1655	int i;
1656	u64 bg_blkno = res->sr_bg_blkno;  /* Save off */
1657	struct ocfs2_extent_rec *rec;
1658	struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1659	struct ocfs2_chain_list *cl = &di->id2.i_chain;
1660
1661	if (ocfs2_is_cluster_bitmap(ac->ac_inode)) {
1662		res->sr_blkno = 0;
1663		return;
1664	}
1665
1666	res->sr_blkno = res->sr_bg_blkno + res->sr_bit_offset;
1667	res->sr_bg_blkno = 0;  /* Clear it for contig block groups */
1668	if (!ocfs2_supports_discontig_bg(OCFS2_SB(ac->ac_inode->i_sb)) ||
1669	    !bg->bg_list.l_next_free_rec)
1670		return;
1671
1672	for (i = 0; i < le16_to_cpu(bg->bg_list.l_next_free_rec); i++) {
1673		rec = &bg->bg_list.l_recs[i];
1674		if (ocfs2_bg_discontig_fix_by_rec(res, rec, cl)) {
1675			res->sr_bg_blkno = bg_blkno;  /* Restore */
1676			break;
1677		}
1678	}
1679}
1680
1681static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
1682				  handle_t *handle,
1683				  u32 bits_wanted,
1684				  u32 min_bits,
1685				  struct ocfs2_suballoc_result *res,
1686				  u16 *bits_left)
1687{
1688	int ret;
1689	struct buffer_head *group_bh = NULL;
1690	struct ocfs2_group_desc *gd;
1691	struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1692	struct inode *alloc_inode = ac->ac_inode;
1693
1694	ret = ocfs2_read_group_descriptor(alloc_inode, di,
1695					  res->sr_bg_blkno, &group_bh);
1696	if (ret < 0) {
1697		mlog_errno(ret);
1698		return ret;
1699	}
1700
1701	gd = (struct ocfs2_group_desc *) group_bh->b_data;
1702	ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
1703				  ac->ac_max_block, res);
1704	if (ret < 0) {
1705		if (ret != -ENOSPC)
1706			mlog_errno(ret);
1707		goto out;
1708	}
1709
1710	if (!ret)
1711		ocfs2_bg_discontig_fix_result(ac, gd, res);
1712
1713	/*
1714	 * sr_bg_blkno might have been changed by
1715	 * ocfs2_bg_discontig_fix_result
1716	 */
1717	res->sr_bg_stable_blkno = group_bh->b_blocknr;
1718
1719	if (ac->ac_find_loc_only)
1720		goto out_loc_only;
1721
1722	ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
1723					       res->sr_bits,
1724					       le16_to_cpu(gd->bg_chain));
1725	if (ret < 0) {
1726		mlog_errno(ret);
1727		goto out;
1728	}
1729
1730	ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
1731					 res->sr_bit_offset, res->sr_bits);
1732	if (ret < 0) {
1733		ocfs2_rollback_alloc_dinode_counts(alloc_inode, ac->ac_bh,
1734					       res->sr_bits,
1735					       le16_to_cpu(gd->bg_chain));
1736		mlog_errno(ret);
1737	}
1738
1739out_loc_only:
1740	*bits_left = le16_to_cpu(gd->bg_free_bits_count);
1741
1742out:
1743	brelse(group_bh);
1744
1745	return ret;
1746}
1747
1748static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
1749			      handle_t *handle,
1750			      u32 bits_wanted,
1751			      u32 min_bits,
1752			      struct ocfs2_suballoc_result *res,
1753			      u16 *bits_left)
1754{
1755	int status;
1756	u16 chain;
1757	u64 next_group;
1758	struct inode *alloc_inode = ac->ac_inode;
1759	struct buffer_head *group_bh = NULL;
1760	struct buffer_head *prev_group_bh = NULL;
1761	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1762	struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1763	struct ocfs2_group_desc *bg;
1764
1765	chain = ac->ac_chain;
1766	trace_ocfs2_search_chain_begin(
1767		(unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
1768		bits_wanted, chain);
1769
1770	status = ocfs2_read_group_descriptor(alloc_inode, fe,
1771					     le64_to_cpu(cl->cl_recs[chain].c_blkno),
1772					     &group_bh);
1773	if (status < 0) {
1774		mlog_errno(status);
1775		goto bail;
1776	}
1777	bg = (struct ocfs2_group_desc *) group_bh->b_data;
1778
1779	status = -ENOSPC;
1780	/* for now, the chain search is a bit simplistic. We just use
1781	 * the 1st group with any empty bits. */
1782	while ((status = ac->ac_group_search(alloc_inode, group_bh,
1783					     bits_wanted, min_bits,
1784					     ac->ac_max_block,
1785					     res)) == -ENOSPC) {
1786		if (!bg->bg_next_group)
1787			break;
1788
1789		brelse(prev_group_bh);
1790		prev_group_bh = NULL;
1791
1792		next_group = le64_to_cpu(bg->bg_next_group);
1793		prev_group_bh = group_bh;
1794		group_bh = NULL;
1795		status = ocfs2_read_group_descriptor(alloc_inode, fe,
1796						     next_group, &group_bh);
1797		if (status < 0) {
1798			mlog_errno(status);
1799			goto bail;
1800		}
1801		bg = (struct ocfs2_group_desc *) group_bh->b_data;
1802	}
1803	if (status < 0) {
1804		if (status != -ENOSPC)
1805			mlog_errno(status);
1806		goto bail;
1807	}
1808
1809	trace_ocfs2_search_chain_succ(
1810		(unsigned long long)le64_to_cpu(bg->bg_blkno), res->sr_bits);
1811
1812	res->sr_bg_blkno = le64_to_cpu(bg->bg_blkno);
1813
1814	BUG_ON(res->sr_bits == 0);
1815	if (!status)
1816		ocfs2_bg_discontig_fix_result(ac, bg, res);
1817
1818	/*
1819	 * sr_bg_blkno might have been changed by
1820	 * ocfs2_bg_discontig_fix_result
1821	 */
1822	res->sr_bg_stable_blkno = group_bh->b_blocknr;
1823
1824	/*
1825	 * Keep track of previous block descriptor read. When
1826	 * we find a target, if we have read more than X
1827	 * number of descriptors, and the target is reasonably
1828	 * empty, relink him to top of his chain.
1829	 *
1830	 * We've read 0 extra blocks and only send one more to
1831	 * the transaction, yet the next guy to search has a
1832	 * much easier time.
1833	 *
1834	 * Do this *after* figuring out how many bits we're taking out
1835	 * of our target group.
1836	 */
1837	if (!ac->ac_disable_chain_relink &&
1838	    (prev_group_bh) &&
1839	    (ocfs2_block_group_reasonably_empty(bg, res->sr_bits))) {
1840		status = ocfs2_relink_block_group(handle, alloc_inode,
1841						  ac->ac_bh, group_bh,
1842						  prev_group_bh, chain);
1843		if (status < 0) {
1844			mlog_errno(status);
1845			goto bail;
1846		}
1847	}
1848
1849	if (ac->ac_find_loc_only)
1850		goto out_loc_only;
1851
1852	status = ocfs2_alloc_dinode_update_counts(alloc_inode, handle,
1853						  ac->ac_bh, res->sr_bits,
1854						  chain);
1855	if (status) {
1856		mlog_errno(status);
1857		goto bail;
1858	}
1859
1860	status = ocfs2_block_group_set_bits(handle,
1861					    alloc_inode,
1862					    bg,
1863					    group_bh,
1864					    res->sr_bit_offset,
1865					    res->sr_bits);
1866	if (status < 0) {
1867		ocfs2_rollback_alloc_dinode_counts(alloc_inode,
1868					ac->ac_bh, res->sr_bits, chain);
1869		mlog_errno(status);
1870		goto bail;
1871	}
1872
1873	trace_ocfs2_search_chain_end(
1874			(unsigned long long)le64_to_cpu(fe->i_blkno),
1875			res->sr_bits);
1876
1877out_loc_only:
1878	*bits_left = le16_to_cpu(bg->bg_free_bits_count);
1879bail:
1880	brelse(group_bh);
1881	brelse(prev_group_bh);
1882
1883	if (status)
1884		mlog_errno(status);
1885	return status;
1886}
1887
1888/* will give out up to bits_wanted contiguous bits. */
1889static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
1890				     handle_t *handle,
1891				     u32 bits_wanted,
1892				     u32 min_bits,
1893				     struct ocfs2_suballoc_result *res)
1894{
1895	int status;
1896	u16 victim, i;
1897	u16 bits_left = 0;
1898	u64 hint = ac->ac_last_group;
1899	struct ocfs2_chain_list *cl;
1900	struct ocfs2_dinode *fe;
1901
1902	BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1903	BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1904	BUG_ON(!ac->ac_bh);
1905
1906	fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1907
1908	/* The bh was validated by the inode read during
1909	 * ocfs2_reserve_suballoc_bits().  Any corruption is a code bug. */
1910	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
1911
1912	if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1913	    le32_to_cpu(fe->id1.bitmap1.i_total)) {
1914		status = ocfs2_error(ac->ac_inode->i_sb,
1915				     "Chain allocator dinode %llu has %u used bits but only %u total\n",
1916				     (unsigned long long)le64_to_cpu(fe->i_blkno),
1917				     le32_to_cpu(fe->id1.bitmap1.i_used),
1918				     le32_to_cpu(fe->id1.bitmap1.i_total));
1919		goto bail;
1920	}
1921
1922	res->sr_bg_blkno = hint;
1923	if (res->sr_bg_blkno) {
1924		/* Attempt to short-circuit the usual search mechanism
1925		 * by jumping straight to the most recently used
1926		 * allocation group. This helps us maintain some
1927		 * contiguousness across allocations. */
1928		status = ocfs2_search_one_group(ac, handle, bits_wanted,
1929						min_bits, res, &bits_left);
1930		if (!status)
1931			goto set_hint;
1932		if (status < 0 && status != -ENOSPC) {
1933			mlog_errno(status);
1934			goto bail;
1935		}
1936	}
1937
1938	cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1939
1940	victim = ocfs2_find_victim_chain(cl);
1941	ac->ac_chain = victim;
1942
1943	status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1944				    res, &bits_left);
1945	if (!status) {
1946		if (ocfs2_is_cluster_bitmap(ac->ac_inode))
1947			hint = res->sr_bg_blkno;
1948		else
1949			hint = ocfs2_group_from_res(res);
1950		goto set_hint;
1951	}
1952	if (status < 0 && status != -ENOSPC) {
1953		mlog_errno(status);
1954		goto bail;
1955	}
1956
1957	trace_ocfs2_claim_suballoc_bits(victim);
1958
1959	/* If we didn't pick a good victim, then just default to
1960	 * searching each chain in order. Don't allow chain relinking
1961	 * because we only calculate enough journal credits for one
1962	 * relink per alloc. */
1963	ac->ac_disable_chain_relink = 1;
1964	for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
1965		if (i == victim)
1966			continue;
1967		if (!cl->cl_recs[i].c_free)
1968			continue;
1969
1970		ac->ac_chain = i;
1971		status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1972					    res, &bits_left);
1973		if (!status) {
1974			hint = ocfs2_group_from_res(res);
1975			break;
1976		}
1977		if (status < 0 && status != -ENOSPC) {
1978			mlog_errno(status);
1979			goto bail;
1980		}
1981	}
1982
1983set_hint:
1984	if (status != -ENOSPC) {
1985		/* If the next search of this group is not likely to
1986		 * yield a suitable extent, then we reset the last
1987		 * group hint so as to not waste a disk read */
1988		if (bits_left < min_bits)
1989			ac->ac_last_group = 0;
1990		else
1991			ac->ac_last_group = hint;
1992	}
1993
1994bail:
1995	if (status)
1996		mlog_errno(status);
1997	return status;
1998}
1999
2000int ocfs2_claim_metadata(handle_t *handle,
2001			 struct ocfs2_alloc_context *ac,
2002			 u32 bits_wanted,
2003			 u64 *suballoc_loc,
2004			 u16 *suballoc_bit_start,
2005			 unsigned int *num_bits,
2006			 u64 *blkno_start)
2007{
2008	int status;
2009	struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
2010
2011	BUG_ON(!ac);
2012	BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
2013	BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
2014
2015	status = ocfs2_claim_suballoc_bits(ac,
2016					   handle,
2017					   bits_wanted,
2018					   1,
2019					   &res);
2020	if (status < 0) {
2021		mlog_errno(status);
2022		goto bail;
2023	}
2024	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2025
2026	*suballoc_loc = res.sr_bg_blkno;
2027	*suballoc_bit_start = res.sr_bit_offset;
2028	*blkno_start = res.sr_blkno;
2029	ac->ac_bits_given += res.sr_bits;
2030	*num_bits = res.sr_bits;
2031	status = 0;
2032bail:
2033	if (status)
2034		mlog_errno(status);
2035	return status;
2036}
2037
2038static void ocfs2_init_inode_ac_group(struct inode *dir,
2039				      struct buffer_head *parent_di_bh,
2040				      struct ocfs2_alloc_context *ac)
2041{
2042	struct ocfs2_dinode *di = (struct ocfs2_dinode *)parent_di_bh->b_data;
2043	/*
2044	 * Try to allocate inodes from some specific group.
2045	 *
2046	 * If the parent dir has recorded the last group used in allocation,
2047	 * cool, use it. Otherwise if we try to allocate new inode from the
2048	 * same slot the parent dir belongs to, use the same chunk.
2049	 *
2050	 * We are very careful here to avoid the mistake of setting
2051	 * ac_last_group to a group descriptor from a different (unlocked) slot.
2052	 */
2053	if (OCFS2_I(dir)->ip_last_used_group &&
2054	    OCFS2_I(dir)->ip_last_used_slot == ac->ac_alloc_slot)
2055		ac->ac_last_group = OCFS2_I(dir)->ip_last_used_group;
2056	else if (le16_to_cpu(di->i_suballoc_slot) == ac->ac_alloc_slot) {
2057		if (di->i_suballoc_loc)
2058			ac->ac_last_group = le64_to_cpu(di->i_suballoc_loc);
2059		else
2060			ac->ac_last_group = ocfs2_which_suballoc_group(
2061					le64_to_cpu(di->i_blkno),
2062					le16_to_cpu(di->i_suballoc_bit));
2063	}
2064}
2065
2066static inline void ocfs2_save_inode_ac_group(struct inode *dir,
2067					     struct ocfs2_alloc_context *ac)
2068{
2069	OCFS2_I(dir)->ip_last_used_group = ac->ac_last_group;
2070	OCFS2_I(dir)->ip_last_used_slot = ac->ac_alloc_slot;
2071}
2072
2073int ocfs2_find_new_inode_loc(struct inode *dir,
2074			     struct buffer_head *parent_fe_bh,
2075			     struct ocfs2_alloc_context *ac,
2076			     u64 *fe_blkno)
2077{
2078	int ret;
2079	handle_t *handle = NULL;
2080	struct ocfs2_suballoc_result *res;
2081
2082	BUG_ON(!ac);
2083	BUG_ON(ac->ac_bits_given != 0);
2084	BUG_ON(ac->ac_bits_wanted != 1);
2085	BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2086
2087	res = kzalloc(sizeof(*res), GFP_NOFS);
2088	if (res == NULL) {
2089		ret = -ENOMEM;
2090		mlog_errno(ret);
2091		goto out;
2092	}
2093
2094	ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2095
2096	/*
2097	 * The handle started here is for chain relink. Alternatively,
2098	 * we could just disable relink for these calls.
2099	 */
2100	handle = ocfs2_start_trans(OCFS2_SB(dir->i_sb), OCFS2_SUBALLOC_ALLOC);
2101	if (IS_ERR(handle)) {
2102		ret = PTR_ERR(handle);
2103		handle = NULL;
2104		mlog_errno(ret);
2105		goto out;
2106	}
2107
2108	/*
2109	 * This will instruct ocfs2_claim_suballoc_bits and
2110	 * ocfs2_search_one_group to search but save actual allocation
2111	 * for later.
2112	 */
2113	ac->ac_find_loc_only = 1;
2114
2115	ret = ocfs2_claim_suballoc_bits(ac, handle, 1, 1, res);
2116	if (ret < 0) {
2117		mlog_errno(ret);
2118		goto out;
2119	}
2120
2121	ac->ac_find_loc_priv = res;
2122	*fe_blkno = res->sr_blkno;
2123	ocfs2_update_inode_fsync_trans(handle, dir, 0);
2124out:
2125	if (handle)
2126		ocfs2_commit_trans(OCFS2_SB(dir->i_sb), handle);
2127
2128	if (ret)
2129		kfree(res);
2130
2131	return ret;
2132}
2133
2134int ocfs2_claim_new_inode_at_loc(handle_t *handle,
2135				 struct inode *dir,
2136				 struct ocfs2_alloc_context *ac,
2137				 u64 *suballoc_loc,
2138				 u16 *suballoc_bit,
2139				 u64 di_blkno)
2140{
2141	int ret;
2142	u16 chain;
2143	struct ocfs2_suballoc_result *res = ac->ac_find_loc_priv;
2144	struct buffer_head *bg_bh = NULL;
2145	struct ocfs2_group_desc *bg;
2146	struct ocfs2_dinode *di = (struct ocfs2_dinode *) ac->ac_bh->b_data;
2147
2148	/*
2149	 * Since di_blkno is being passed back in, we check for any
2150	 * inconsistencies which may have happened between
2151	 * calls. These are code bugs as di_blkno is not expected to
2152	 * change once returned from ocfs2_find_new_inode_loc()
2153	 */
2154	BUG_ON(res->sr_blkno != di_blkno);
2155
2156	ret = ocfs2_read_group_descriptor(ac->ac_inode, di,
2157					  res->sr_bg_stable_blkno, &bg_bh);
2158	if (ret) {
2159		mlog_errno(ret);
2160		goto out;
2161	}
2162
2163	bg = (struct ocfs2_group_desc *) bg_bh->b_data;
2164	chain = le16_to_cpu(bg->bg_chain);
2165
2166	ret = ocfs2_alloc_dinode_update_counts(ac->ac_inode, handle,
2167					       ac->ac_bh, res->sr_bits,
2168					       chain);
2169	if (ret) {
2170		mlog_errno(ret);
2171		goto out;
2172	}
2173
2174	ret = ocfs2_block_group_set_bits(handle,
2175					 ac->ac_inode,
2176					 bg,
2177					 bg_bh,
2178					 res->sr_bit_offset,
2179					 res->sr_bits);
2180	if (ret < 0) {
2181		ocfs2_rollback_alloc_dinode_counts(ac->ac_inode,
2182					       ac->ac_bh, res->sr_bits, chain);
2183		mlog_errno(ret);
2184		goto out;
2185	}
2186
2187	trace_ocfs2_claim_new_inode_at_loc((unsigned long long)di_blkno,
2188					   res->sr_bits);
2189
2190	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2191
2192	BUG_ON(res->sr_bits != 1);
2193
2194	*suballoc_loc = res->sr_bg_blkno;
2195	*suballoc_bit = res->sr_bit_offset;
2196	ac->ac_bits_given++;
2197	ocfs2_save_inode_ac_group(dir, ac);
2198
2199out:
2200	brelse(bg_bh);
2201
2202	return ret;
2203}
2204
2205int ocfs2_claim_new_inode(handle_t *handle,
2206			  struct inode *dir,
2207			  struct buffer_head *parent_fe_bh,
2208			  struct ocfs2_alloc_context *ac,
2209			  u64 *suballoc_loc,
2210			  u16 *suballoc_bit,
2211			  u64 *fe_blkno)
2212{
2213	int status;
2214	struct ocfs2_suballoc_result res;
2215
2216	BUG_ON(!ac);
2217	BUG_ON(ac->ac_bits_given != 0);
2218	BUG_ON(ac->ac_bits_wanted != 1);
2219	BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2220
2221	ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2222
2223	status = ocfs2_claim_suballoc_bits(ac,
2224					   handle,
2225					   1,
2226					   1,
2227					   &res);
2228	if (status < 0) {
2229		mlog_errno(status);
2230		goto bail;
2231	}
2232	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2233
2234	BUG_ON(res.sr_bits != 1);
2235
2236	*suballoc_loc = res.sr_bg_blkno;
2237	*suballoc_bit = res.sr_bit_offset;
2238	*fe_blkno = res.sr_blkno;
2239	ac->ac_bits_given++;
2240	ocfs2_save_inode_ac_group(dir, ac);
2241	status = 0;
2242bail:
2243	if (status)
2244		mlog_errno(status);
2245	return status;
2246}
2247
2248/* translate a group desc. blkno and it's bitmap offset into
2249 * disk cluster offset. */
2250static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
2251						   u64 bg_blkno,
2252						   u16 bg_bit_off)
2253{
2254	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2255	u32 cluster = 0;
2256
2257	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2258
2259	if (bg_blkno != osb->first_cluster_group_blkno)
2260		cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
2261	cluster += (u32) bg_bit_off;
2262	return cluster;
2263}
2264
2265/* given a cluster offset, calculate which block group it belongs to
2266 * and return that block offset. */
2267u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster)
2268{
2269	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2270	u32 group_no;
2271
2272	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2273
2274	group_no = cluster / osb->bitmap_cpg;
2275	if (!group_no)
2276		return osb->first_cluster_group_blkno;
2277	return ocfs2_clusters_to_blocks(inode->i_sb,
2278					group_no * osb->bitmap_cpg);
2279}
2280
2281/* given the block number of a cluster start, calculate which cluster
2282 * group and descriptor bitmap offset that corresponds to. */
2283static inline void ocfs2_block_to_cluster_group(struct inode *inode,
2284						u64 data_blkno,
2285						u64 *bg_blkno,
2286						u16 *bg_bit_off)
2287{
2288	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2289	u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
2290
2291	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2292
2293	*bg_blkno = ocfs2_which_cluster_group(inode,
2294					      data_cluster);
2295
2296	if (*bg_blkno == osb->first_cluster_group_blkno)
2297		*bg_bit_off = (u16) data_cluster;
2298	else
2299		*bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
2300							     data_blkno - *bg_blkno);
2301}
2302
2303/*
2304 * min_bits - minimum contiguous chunk from this total allocation we
2305 * can handle. set to what we asked for originally for a full
2306 * contig. allocation, set to '1' to indicate we can deal with extents
2307 * of any size.
2308 */
2309int __ocfs2_claim_clusters(handle_t *handle,
2310			   struct ocfs2_alloc_context *ac,
2311			   u32 min_clusters,
2312			   u32 max_clusters,
2313			   u32 *cluster_start,
2314			   u32 *num_clusters)
2315{
2316	int status;
2317	unsigned int bits_wanted = max_clusters;
2318	struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
2319	struct ocfs2_super *osb = OCFS2_SB(ac->ac_inode->i_sb);
2320
2321	BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
2322
2323	BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
2324	       && ac->ac_which != OCFS2_AC_USE_MAIN);
2325
2326	if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
2327		WARN_ON(min_clusters > 1);
2328
2329		status = ocfs2_claim_local_alloc_bits(osb,
2330						      handle,
2331						      ac,
2332						      bits_wanted,
2333						      cluster_start,
2334						      num_clusters);
2335		if (!status)
2336			atomic_inc(&osb->alloc_stats.local_data);
2337	} else {
2338		if (min_clusters > (osb->bitmap_cpg - 1)) {
2339			/* The only paths asking for contiguousness
2340			 * should know about this already. */
2341			mlog(ML_ERROR, "minimum allocation requested %u exceeds "
2342			     "group bitmap size %u!\n", min_clusters,
2343			     osb->bitmap_cpg);
2344			status = -ENOSPC;
2345			goto bail;
2346		}
2347		/* clamp the current request down to a realistic size. */
2348		if (bits_wanted > (osb->bitmap_cpg - 1))
2349			bits_wanted = osb->bitmap_cpg - 1;
2350
2351		status = ocfs2_claim_suballoc_bits(ac,
2352						   handle,
2353						   bits_wanted,
2354						   min_clusters,
2355						   &res);
2356		if (!status) {
2357			BUG_ON(res.sr_blkno); /* cluster alloc can't set */
2358			*cluster_start =
2359				ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
2360								 res.sr_bg_blkno,
2361								 res.sr_bit_offset);
2362			atomic_inc(&osb->alloc_stats.bitmap_data);
2363			*num_clusters = res.sr_bits;
2364		}
2365	}
2366	if (status < 0) {
2367		if (status != -ENOSPC)
2368			mlog_errno(status);
2369		goto bail;
2370	}
2371
2372	ac->ac_bits_given += *num_clusters;
2373
2374bail:
2375	if (status)
2376		mlog_errno(status);
2377	return status;
2378}
2379
2380int ocfs2_claim_clusters(handle_t *handle,
2381			 struct ocfs2_alloc_context *ac,
2382			 u32 min_clusters,
2383			 u32 *cluster_start,
2384			 u32 *num_clusters)
2385{
2386	unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
2387
2388	return __ocfs2_claim_clusters(handle, ac, min_clusters,
2389				      bits_wanted, cluster_start, num_clusters);
2390}
2391
2392static int ocfs2_block_group_clear_bits(handle_t *handle,
2393					struct inode *alloc_inode,
2394					struct ocfs2_group_desc *bg,
2395					struct buffer_head *group_bh,
2396					unsigned int bit_off,
2397					unsigned int num_bits,
2398					void (*undo_fn)(unsigned int bit,
2399							unsigned long *bmap))
2400{
2401	int status;
2402	unsigned int tmp;
2403	struct ocfs2_group_desc *undo_bg = NULL;
2404
2405	/* The caller got this descriptor from
2406	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
2407	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
2408
2409	trace_ocfs2_block_group_clear_bits(bit_off, num_bits);
2410
2411	BUG_ON(undo_fn && !ocfs2_is_cluster_bitmap(alloc_inode));
2412	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
2413					 group_bh,
2414					 undo_fn ?
2415					 OCFS2_JOURNAL_ACCESS_UNDO :
2416					 OCFS2_JOURNAL_ACCESS_WRITE);
2417	if (status < 0) {
2418		mlog_errno(status);
2419		goto bail;
2420	}
2421
2422	if (undo_fn) {
2423		jbd_lock_bh_state(group_bh);
2424		undo_bg = (struct ocfs2_group_desc *)
2425					bh2jh(group_bh)->b_committed_data;
2426		BUG_ON(!undo_bg);
2427	}
2428
2429	tmp = num_bits;
2430	while(tmp--) {
2431		ocfs2_clear_bit((bit_off + tmp),
2432				(unsigned long *) bg->bg_bitmap);
2433		if (undo_fn)
2434			undo_fn(bit_off + tmp,
2435				(unsigned long *) undo_bg->bg_bitmap);
2436	}
2437	le16_add_cpu(&bg->bg_free_bits_count, num_bits);
2438	if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
2439		if (undo_fn)
2440			jbd_unlock_bh_state(group_bh);
2441		return ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit count %u but claims %u are freed. num_bits %d\n",
2442				   (unsigned long long)le64_to_cpu(bg->bg_blkno),
2443				   le16_to_cpu(bg->bg_bits),
2444				   le16_to_cpu(bg->bg_free_bits_count),
2445				   num_bits);
2446	}
2447
2448	if (undo_fn)
2449		jbd_unlock_bh_state(group_bh);
2450
2451	ocfs2_journal_dirty(handle, group_bh);
2452bail:
2453	return status;
2454}
2455
2456/*
2457 * expects the suballoc inode to already be locked.
2458 */
2459static int _ocfs2_free_suballoc_bits(handle_t *handle,
2460				     struct inode *alloc_inode,
2461				     struct buffer_head *alloc_bh,
2462				     unsigned int start_bit,
2463				     u64 bg_blkno,
2464				     unsigned int count,
2465				     void (*undo_fn)(unsigned int bit,
2466						     unsigned long *bitmap))
2467{
2468	int status = 0;
2469	u32 tmp_used;
2470	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
2471	struct ocfs2_chain_list *cl = &fe->id2.i_chain;
2472	struct buffer_head *group_bh = NULL;
2473	struct ocfs2_group_desc *group;
2474
2475	/* The alloc_bh comes from ocfs2_free_dinode() or
2476	 * ocfs2_free_clusters().  The callers have all locked the
2477	 * allocator and gotten alloc_bh from the lock call.  This
2478	 * validates the dinode buffer.  Any corruption that has happened
2479	 * is a code bug. */
2480	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
2481	BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
2482
2483	trace_ocfs2_free_suballoc_bits(
2484		(unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
2485		(unsigned long long)bg_blkno,
2486		start_bit, count);
2487
2488	status = ocfs2_read_group_descriptor(alloc_inode, fe, bg_blkno,
2489					     &group_bh);
2490	if (status < 0) {
2491		mlog_errno(status);
2492		goto bail;
2493	}
2494	group = (struct ocfs2_group_desc *) group_bh->b_data;
2495
2496	BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
2497
2498	status = ocfs2_block_group_clear_bits(handle, alloc_inode,
2499					      group, group_bh,
2500					      start_bit, count, undo_fn);
2501	if (status < 0) {
2502		mlog_errno(status);
2503		goto bail;
2504	}
2505
2506	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
2507					 alloc_bh, OCFS2_JOURNAL_ACCESS_WRITE);
2508	if (status < 0) {
2509		mlog_errno(status);
2510		ocfs2_block_group_set_bits(handle, alloc_inode, group, group_bh,
2511				start_bit, count);
2512		goto bail;
2513	}
2514
2515	le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
2516		     count);
2517	tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
2518	fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
2519	ocfs2_journal_dirty(handle, alloc_bh);
2520
2521bail:
2522	brelse(group_bh);
2523
2524	if (status)
2525		mlog_errno(status);
2526	return status;
2527}
2528
2529int ocfs2_free_suballoc_bits(handle_t *handle,
2530			     struct inode *alloc_inode,
2531			     struct buffer_head *alloc_bh,
2532			     unsigned int start_bit,
2533			     u64 bg_blkno,
2534			     unsigned int count)
2535{
2536	return _ocfs2_free_suballoc_bits(handle, alloc_inode, alloc_bh,
2537					 start_bit, bg_blkno, count, NULL);
2538}
2539
2540int ocfs2_free_dinode(handle_t *handle,
2541		      struct inode *inode_alloc_inode,
2542		      struct buffer_head *inode_alloc_bh,
2543		      struct ocfs2_dinode *di)
2544{
2545	u64 blk = le64_to_cpu(di->i_blkno);
2546	u16 bit = le16_to_cpu(di->i_suballoc_bit);
2547	u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
2548
2549	if (di->i_suballoc_loc)
2550		bg_blkno = le64_to_cpu(di->i_suballoc_loc);
2551	return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
2552					inode_alloc_bh, bit, bg_blkno, 1);
2553}
2554
2555static int _ocfs2_free_clusters(handle_t *handle,
2556				struct inode *bitmap_inode,
2557				struct buffer_head *bitmap_bh,
2558				u64 start_blk,
2559				unsigned int num_clusters,
2560				void (*undo_fn)(unsigned int bit,
2561						unsigned long *bitmap))
2562{
2563	int status;
2564	u16 bg_start_bit;
2565	u64 bg_blkno;
2566
2567	/* You can't ever have a contiguous set of clusters
2568	 * bigger than a block group bitmap so we never have to worry
2569	 * about looping on them.
2570	 * This is expensive. We can safely remove once this stuff has
2571	 * gotten tested really well. */
2572	BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb,
2573				ocfs2_blocks_to_clusters(bitmap_inode->i_sb,
2574							 start_blk)));
2575
2576
2577	ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
2578				     &bg_start_bit);
2579
2580	trace_ocfs2_free_clusters((unsigned long long)bg_blkno,
2581			(unsigned long long)start_blk,
2582			bg_start_bit, num_clusters);
2583
2584	status = _ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
2585					   bg_start_bit, bg_blkno,
2586					   num_clusters, undo_fn);
2587	if (status < 0) {
2588		mlog_errno(status);
2589		goto out;
2590	}
2591
2592	ocfs2_local_alloc_seen_free_bits(OCFS2_SB(bitmap_inode->i_sb),
2593					 num_clusters);
2594
2595out:
2596	if (status)
2597		mlog_errno(status);
2598	return status;
2599}
2600
2601int ocfs2_free_clusters(handle_t *handle,
2602			struct inode *bitmap_inode,
2603			struct buffer_head *bitmap_bh,
2604			u64 start_blk,
2605			unsigned int num_clusters)
2606{
2607	return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2608				    start_blk, num_clusters,
2609				    _ocfs2_set_bit);
2610}
2611
2612/*
2613 * Give never-used clusters back to the global bitmap.  We don't need
2614 * to protect these bits in the undo buffer.
2615 */
2616int ocfs2_release_clusters(handle_t *handle,
2617			   struct inode *bitmap_inode,
2618			   struct buffer_head *bitmap_bh,
2619			   u64 start_blk,
2620			   unsigned int num_clusters)
2621{
2622	return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2623				    start_blk, num_clusters,
2624				    _ocfs2_clear_bit);
2625}
2626
2627/*
2628 * For a given allocation, determine which allocators will need to be
2629 * accessed, and lock them, reserving the appropriate number of bits.
2630 *
2631 * Sparse file systems call this from ocfs2_write_begin_nolock()
2632 * and ocfs2_allocate_unwritten_extents().
2633 *
2634 * File systems which don't support holes call this from
2635 * ocfs2_extend_allocation().
2636 */
2637int ocfs2_lock_allocators(struct inode *inode,
2638			  struct ocfs2_extent_tree *et,
2639			  u32 clusters_to_add, u32 extents_to_split,
2640			  struct ocfs2_alloc_context **data_ac,
2641			  struct ocfs2_alloc_context **meta_ac)
2642{
2643	int ret = 0, num_free_extents;
2644	unsigned int max_recs_needed = clusters_to_add + 2 * extents_to_split;
2645	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2646
2647	*meta_ac = NULL;
2648	if (data_ac)
2649		*data_ac = NULL;
2650
2651	BUG_ON(clusters_to_add != 0 && data_ac == NULL);
2652
2653	num_free_extents = ocfs2_num_free_extents(et);
2654	if (num_free_extents < 0) {
2655		ret = num_free_extents;
2656		mlog_errno(ret);
2657		goto out;
2658	}
2659
2660	/*
2661	 * Sparse allocation file systems need to be more conservative
2662	 * with reserving room for expansion - the actual allocation
2663	 * happens while we've got a journal handle open so re-taking
2664	 * a cluster lock (because we ran out of room for another
2665	 * extent) will violate ordering rules.
2666	 *
2667	 * Most of the time we'll only be seeing this 1 cluster at a time
2668	 * anyway.
2669	 *
2670	 * Always lock for any unwritten extents - we might want to
2671	 * add blocks during a split.
2672	 */
2673	if (!num_free_extents ||
2674	    (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed)) {
2675		ret = ocfs2_reserve_new_metadata(osb, et->et_root_el, meta_ac);
2676		if (ret < 0) {
2677			if (ret != -ENOSPC)
2678				mlog_errno(ret);
2679			goto out;
2680		}
2681	}
2682
2683	if (clusters_to_add == 0)
2684		goto out;
2685
2686	ret = ocfs2_reserve_clusters(osb, clusters_to_add, data_ac);
2687	if (ret < 0) {
2688		if (ret != -ENOSPC)
2689			mlog_errno(ret);
2690		goto out;
2691	}
2692
2693out:
2694	if (ret) {
2695		if (*meta_ac) {
2696			ocfs2_free_alloc_context(*meta_ac);
2697			*meta_ac = NULL;
2698		}
2699
2700		/*
2701		 * We cannot have an error and a non null *data_ac.
2702		 */
2703	}
2704
2705	return ret;
2706}
2707
2708/*
2709 * Read the inode specified by blkno to get suballoc_slot and
2710 * suballoc_bit.
2711 */
2712static int ocfs2_get_suballoc_slot_bit(struct ocfs2_super *osb, u64 blkno,
2713				       u16 *suballoc_slot, u64 *group_blkno,
2714				       u16 *suballoc_bit)
2715{
2716	int status;
2717	struct buffer_head *inode_bh = NULL;
2718	struct ocfs2_dinode *inode_fe;
2719
2720	trace_ocfs2_get_suballoc_slot_bit((unsigned long long)blkno);
2721
2722	/* dirty read disk */
2723	status = ocfs2_read_blocks_sync(osb, blkno, 1, &inode_bh);
2724	if (status < 0) {
2725		mlog(ML_ERROR, "read block %llu failed %d\n",
2726		     (unsigned long long)blkno, status);
2727		goto bail;
2728	}
2729
2730	inode_fe = (struct ocfs2_dinode *) inode_bh->b_data;
2731	if (!OCFS2_IS_VALID_DINODE(inode_fe)) {
2732		mlog(ML_ERROR, "invalid inode %llu requested\n",
2733		     (unsigned long long)blkno);
2734		status = -EINVAL;
2735		goto bail;
2736	}
2737
2738	if (le16_to_cpu(inode_fe->i_suballoc_slot) != (u16)OCFS2_INVALID_SLOT &&
2739	    (u32)le16_to_cpu(inode_fe->i_suballoc_slot) > osb->max_slots - 1) {
2740		mlog(ML_ERROR, "inode %llu has invalid suballoc slot %u\n",
2741		     (unsigned long long)blkno,
2742		     (u32)le16_to_cpu(inode_fe->i_suballoc_slot));
2743		status = -EINVAL;
2744		goto bail;
2745	}
2746
2747	if (suballoc_slot)
2748		*suballoc_slot = le16_to_cpu(inode_fe->i_suballoc_slot);
2749	if (suballoc_bit)
2750		*suballoc_bit = le16_to_cpu(inode_fe->i_suballoc_bit);
2751	if (group_blkno)
2752		*group_blkno = le64_to_cpu(inode_fe->i_suballoc_loc);
2753
2754bail:
2755	brelse(inode_bh);
2756
2757	if (status)
2758		mlog_errno(status);
2759	return status;
2760}
2761
2762/*
2763 * test whether bit is SET in allocator bitmap or not.  on success, 0
2764 * is returned and *res is 1 for SET; 0 otherwise.  when fails, errno
2765 * is returned and *res is meaningless.  Call this after you have
2766 * cluster locked against suballoc, or you may get a result based on
2767 * non-up2date contents
2768 */
2769static int ocfs2_test_suballoc_bit(struct ocfs2_super *osb,
2770				   struct inode *suballoc,
2771				   struct buffer_head *alloc_bh,
2772				   u64 group_blkno, u64 blkno,
2773				   u16 bit, int *res)
2774{
2775	struct ocfs2_dinode *alloc_di;
2776	struct ocfs2_group_desc *group;
2777	struct buffer_head *group_bh = NULL;
2778	u64 bg_blkno;
2779	int status;
2780
2781	trace_ocfs2_test_suballoc_bit((unsigned long long)blkno,
2782				      (unsigned int)bit);
2783
2784	alloc_di = (struct ocfs2_dinode *)alloc_bh->b_data;
2785	if ((bit + 1) > ocfs2_bits_per_group(&alloc_di->id2.i_chain)) {
2786		mlog(ML_ERROR, "suballoc bit %u out of range of %u\n",
2787		     (unsigned int)bit,
2788		     ocfs2_bits_per_group(&alloc_di->id2.i_chain));
2789		status = -EINVAL;
2790		goto bail;
2791	}
2792
2793	bg_blkno = group_blkno ? group_blkno :
2794		   ocfs2_which_suballoc_group(blkno, bit);
2795	status = ocfs2_read_group_descriptor(suballoc, alloc_di, bg_blkno,
2796					     &group_bh);
2797	if (status < 0) {
2798		mlog(ML_ERROR, "read group %llu failed %d\n",
2799		     (unsigned long long)bg_blkno, status);
2800		goto bail;
2801	}
2802
2803	group = (struct ocfs2_group_desc *) group_bh->b_data;
2804	*res = ocfs2_test_bit(bit, (unsigned long *)group->bg_bitmap);
2805
2806bail:
2807	brelse(group_bh);
2808
2809	if (status)
2810		mlog_errno(status);
2811	return status;
2812}
2813
2814/*
2815 * Test if the bit representing this inode (blkno) is set in the
2816 * suballocator.
2817 *
2818 * On success, 0 is returned and *res is 1 for SET; 0 otherwise.
2819 *
2820 * In the event of failure, a negative value is returned and *res is
2821 * meaningless.
2822 *
2823 * Callers must make sure to hold nfs_sync_lock to prevent
2824 * ocfs2_delete_inode() on another node from accessing the same
2825 * suballocator concurrently.
2826 */
2827int ocfs2_test_inode_bit(struct ocfs2_super *osb, u64 blkno, int *res)
2828{
2829	int status;
2830	u64 group_blkno = 0;
2831	u16 suballoc_bit = 0, suballoc_slot = 0;
2832	struct inode *inode_alloc_inode;
2833	struct buffer_head *alloc_bh = NULL;
2834
2835	trace_ocfs2_test_inode_bit((unsigned long long)blkno);
2836
2837	status = ocfs2_get_suballoc_slot_bit(osb, blkno, &suballoc_slot,
2838					     &group_blkno, &suballoc_bit);
2839	if (status < 0) {
2840		mlog(ML_ERROR, "get alloc slot and bit failed %d\n", status);
2841		goto bail;
2842	}
2843
2844	inode_alloc_inode =
2845		ocfs2_get_system_file_inode(osb, INODE_ALLOC_SYSTEM_INODE,
2846					    suballoc_slot);
2847	if (!inode_alloc_inode) {
2848		/* the error code could be inaccurate, but we are not able to
2849		 * get the correct one. */
2850		status = -EINVAL;
2851		mlog(ML_ERROR, "unable to get alloc inode in slot %u\n",
2852		     (u32)suballoc_slot);
2853		goto bail;
2854	}
2855
2856	inode_lock(inode_alloc_inode);
2857	status = ocfs2_inode_lock(inode_alloc_inode, &alloc_bh, 0);
2858	if (status < 0) {
2859		inode_unlock(inode_alloc_inode);
2860		iput(inode_alloc_inode);
2861		mlog(ML_ERROR, "lock on alloc inode on slot %u failed %d\n",
2862		     (u32)suballoc_slot, status);
2863		goto bail;
2864	}
2865
2866	status = ocfs2_test_suballoc_bit(osb, inode_alloc_inode, alloc_bh,
2867					 group_blkno, blkno, suballoc_bit, res);
2868	if (status < 0)
2869		mlog(ML_ERROR, "test suballoc bit failed %d\n", status);
2870
2871	ocfs2_inode_unlock(inode_alloc_inode, 0);
2872	inode_unlock(inode_alloc_inode);
2873
2874	iput(inode_alloc_inode);
2875	brelse(alloc_bh);
2876bail:
2877	if (status)
2878		mlog_errno(status);
2879	return status;
2880}