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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}
v6.2
   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
 
 
   3 * suballoc.c
   4 *
   5 * metadata alloc and free
   6 * Inspired by ext3 block groups.
   7 *
   8 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
   9 */
  10
  11#include <linux/fs.h>
  12#include <linux/types.h>
  13#include <linux/slab.h>
  14#include <linux/highmem.h>
  15
  16#include <cluster/masklog.h>
  17
  18#include "ocfs2.h"
  19
  20#include "alloc.h"
  21#include "blockcheck.h"
  22#include "dlmglue.h"
  23#include "inode.h"
  24#include "journal.h"
  25#include "localalloc.h"
  26#include "suballoc.h"
  27#include "super.h"
  28#include "sysfile.h"
  29#include "uptodate.h"
  30#include "ocfs2_trace.h"
  31
  32#include "buffer_head_io.h"
  33
  34#define NOT_ALLOC_NEW_GROUP		0
  35#define ALLOC_NEW_GROUP			0x1
  36#define ALLOC_GROUPS_FROM_GLOBAL	0x2
  37
  38#define OCFS2_MAX_TO_STEAL		1024
  39
  40struct ocfs2_suballoc_result {
  41	u64		sr_bg_blkno;	/* The bg we allocated from.  Set
  42					   to 0 when a block group is
  43					   contiguous. */
  44	u64		sr_bg_stable_blkno; /*
  45					     * Doesn't change, always
  46					     * set to target block
  47					     * group descriptor
  48					     * block.
  49					     */
  50	u64		sr_blkno;	/* The first allocated block */
  51	unsigned int	sr_bit_offset;	/* The bit in the bg */
  52	unsigned int	sr_bits;	/* How many bits we claimed */
  53};
  54
  55static u64 ocfs2_group_from_res(struct ocfs2_suballoc_result *res)
  56{
  57	if (res->sr_blkno == 0)
  58		return 0;
  59
  60	if (res->sr_bg_blkno)
  61		return res->sr_bg_blkno;
  62
  63	return ocfs2_which_suballoc_group(res->sr_blkno, res->sr_bit_offset);
  64}
  65
  66static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl);
  67static int ocfs2_block_group_fill(handle_t *handle,
  68				  struct inode *alloc_inode,
  69				  struct buffer_head *bg_bh,
  70				  u64 group_blkno,
  71				  unsigned int group_clusters,
  72				  u16 my_chain,
  73				  struct ocfs2_chain_list *cl);
  74static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
  75				   struct inode *alloc_inode,
  76				   struct buffer_head *bh,
  77				   u64 max_block,
  78				   u64 *last_alloc_group,
  79				   int flags);
  80
  81static int ocfs2_cluster_group_search(struct inode *inode,
  82				      struct buffer_head *group_bh,
  83				      u32 bits_wanted, u32 min_bits,
  84				      u64 max_block,
  85				      struct ocfs2_suballoc_result *res);
  86static int ocfs2_block_group_search(struct inode *inode,
  87				    struct buffer_head *group_bh,
  88				    u32 bits_wanted, u32 min_bits,
  89				    u64 max_block,
  90				    struct ocfs2_suballoc_result *res);
  91static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
  92				     handle_t *handle,
  93				     u32 bits_wanted,
  94				     u32 min_bits,
  95				     struct ocfs2_suballoc_result *res);
  96static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
  97					 int nr);
  98static int ocfs2_relink_block_group(handle_t *handle,
  99				    struct inode *alloc_inode,
 100				    struct buffer_head *fe_bh,
 101				    struct buffer_head *bg_bh,
 102				    struct buffer_head *prev_bg_bh,
 103				    u16 chain);
 104static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
 105						     u32 wanted);
 106static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
 107						   u64 bg_blkno,
 108						   u16 bg_bit_off);
 109static inline void ocfs2_block_to_cluster_group(struct inode *inode,
 110						u64 data_blkno,
 111						u64 *bg_blkno,
 112						u16 *bg_bit_off);
 113static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
 114					     u32 bits_wanted, u64 max_block,
 115					     int flags,
 116					     struct ocfs2_alloc_context **ac);
 117
 118void ocfs2_free_ac_resource(struct ocfs2_alloc_context *ac)
 119{
 120	struct inode *inode = ac->ac_inode;
 121
 122	if (inode) {
 123		if (ac->ac_which != OCFS2_AC_USE_LOCAL)
 124			ocfs2_inode_unlock(inode, 1);
 125
 126		inode_unlock(inode);
 127
 128		iput(inode);
 129		ac->ac_inode = NULL;
 130	}
 131	brelse(ac->ac_bh);
 132	ac->ac_bh = NULL;
 133	ac->ac_resv = NULL;
 134	kfree(ac->ac_find_loc_priv);
 135	ac->ac_find_loc_priv = NULL;
 136}
 137
 138void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
 139{
 140	ocfs2_free_ac_resource(ac);
 141	kfree(ac);
 142}
 143
 144static u32 ocfs2_bits_per_group(struct ocfs2_chain_list *cl)
 145{
 146	return (u32)le16_to_cpu(cl->cl_cpg) * (u32)le16_to_cpu(cl->cl_bpc);
 147}
 148
 149#define do_error(fmt, ...)						\
 150do {									\
 151	if (resize)							\
 152		mlog(ML_ERROR, fmt, ##__VA_ARGS__);			\
 153	else								\
 154		return ocfs2_error(sb, fmt, ##__VA_ARGS__);		\
 155} while (0)
 156
 157static int ocfs2_validate_gd_self(struct super_block *sb,
 158				  struct buffer_head *bh,
 159				  int resize)
 160{
 161	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 162
 163	if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
 164		do_error("Group descriptor #%llu has bad signature %.*s\n",
 165			 (unsigned long long)bh->b_blocknr, 7,
 166			 gd->bg_signature);
 167	}
 168
 169	if (le64_to_cpu(gd->bg_blkno) != bh->b_blocknr) {
 170		do_error("Group descriptor #%llu has an invalid bg_blkno of %llu\n",
 171			 (unsigned long long)bh->b_blocknr,
 172			 (unsigned long long)le64_to_cpu(gd->bg_blkno));
 173	}
 174
 175	if (le32_to_cpu(gd->bg_generation) != OCFS2_SB(sb)->fs_generation) {
 176		do_error("Group descriptor #%llu has an invalid fs_generation of #%u\n",
 177			 (unsigned long long)bh->b_blocknr,
 178			 le32_to_cpu(gd->bg_generation));
 179	}
 180
 181	if (le16_to_cpu(gd->bg_free_bits_count) > le16_to_cpu(gd->bg_bits)) {
 182		do_error("Group descriptor #%llu has bit count %u but claims that %u are free\n",
 183			 (unsigned long long)bh->b_blocknr,
 184			 le16_to_cpu(gd->bg_bits),
 185			 le16_to_cpu(gd->bg_free_bits_count));
 186	}
 187
 188	if (le16_to_cpu(gd->bg_bits) > (8 * le16_to_cpu(gd->bg_size))) {
 189		do_error("Group descriptor #%llu has bit count %u but max bitmap bits of %u\n",
 190			 (unsigned long long)bh->b_blocknr,
 191			 le16_to_cpu(gd->bg_bits),
 192			 8 * le16_to_cpu(gd->bg_size));
 193	}
 194
 195	return 0;
 196}
 197
 198static int ocfs2_validate_gd_parent(struct super_block *sb,
 199				    struct ocfs2_dinode *di,
 200				    struct buffer_head *bh,
 201				    int resize)
 202{
 203	unsigned int max_bits;
 204	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 205
 206	if (di->i_blkno != gd->bg_parent_dinode) {
 207		do_error("Group descriptor #%llu has bad parent pointer (%llu, expected %llu)\n",
 208			 (unsigned long long)bh->b_blocknr,
 209			 (unsigned long long)le64_to_cpu(gd->bg_parent_dinode),
 210			 (unsigned long long)le64_to_cpu(di->i_blkno));
 211	}
 212
 213	max_bits = le16_to_cpu(di->id2.i_chain.cl_cpg) * le16_to_cpu(di->id2.i_chain.cl_bpc);
 214	if (le16_to_cpu(gd->bg_bits) > max_bits) {
 215		do_error("Group descriptor #%llu has bit count of %u\n",
 216			 (unsigned long long)bh->b_blocknr,
 217			 le16_to_cpu(gd->bg_bits));
 218	}
 219
 220	/* In resize, we may meet the case bg_chain == cl_next_free_rec. */
 221	if ((le16_to_cpu(gd->bg_chain) >
 222	     le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) ||
 223	    ((le16_to_cpu(gd->bg_chain) ==
 224	     le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) && !resize)) {
 225		do_error("Group descriptor #%llu has bad chain %u\n",
 226			 (unsigned long long)bh->b_blocknr,
 227			 le16_to_cpu(gd->bg_chain));
 228	}
 229
 230	return 0;
 231}
 232
 233#undef do_error
 234
 235/*
 236 * This version only prints errors.  It does not fail the filesystem, and
 237 * exists only for resize.
 238 */
 239int ocfs2_check_group_descriptor(struct super_block *sb,
 240				 struct ocfs2_dinode *di,
 241				 struct buffer_head *bh)
 242{
 243	int rc;
 244	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 245
 246	BUG_ON(!buffer_uptodate(bh));
 247
 248	/*
 249	 * If the ecc fails, we return the error but otherwise
 250	 * leave the filesystem running.  We know any error is
 251	 * local to this block.
 252	 */
 253	rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
 254	if (rc) {
 255		mlog(ML_ERROR,
 256		     "Checksum failed for group descriptor %llu\n",
 257		     (unsigned long long)bh->b_blocknr);
 258	} else
 259		rc = ocfs2_validate_gd_self(sb, bh, 1);
 260	if (!rc)
 261		rc = ocfs2_validate_gd_parent(sb, di, bh, 1);
 262
 263	return rc;
 264}
 265
 266static int ocfs2_validate_group_descriptor(struct super_block *sb,
 267					   struct buffer_head *bh)
 268{
 269	int rc;
 270	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 271
 272	trace_ocfs2_validate_group_descriptor(
 273					(unsigned long long)bh->b_blocknr);
 274
 275	BUG_ON(!buffer_uptodate(bh));
 276
 277	/*
 278	 * If the ecc fails, we return the error but otherwise
 279	 * leave the filesystem running.  We know any error is
 280	 * local to this block.
 281	 */
 282	rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
 283	if (rc)
 284		return rc;
 285
 286	/*
 287	 * Errors after here are fatal.
 288	 */
 289
 290	return ocfs2_validate_gd_self(sb, bh, 0);
 291}
 292
 293int ocfs2_read_group_descriptor(struct inode *inode, struct ocfs2_dinode *di,
 294				u64 gd_blkno, struct buffer_head **bh)
 295{
 296	int rc;
 297	struct buffer_head *tmp = *bh;
 298
 299	rc = ocfs2_read_block(INODE_CACHE(inode), gd_blkno, &tmp,
 300			      ocfs2_validate_group_descriptor);
 301	if (rc)
 302		goto out;
 303
 304	rc = ocfs2_validate_gd_parent(inode->i_sb, di, tmp, 0);
 305	if (rc) {
 306		brelse(tmp);
 307		goto out;
 308	}
 309
 310	/* If ocfs2_read_block() got us a new bh, pass it up. */
 311	if (!*bh)
 312		*bh = tmp;
 313
 314out:
 315	return rc;
 316}
 317
 318static void ocfs2_bg_discontig_add_extent(struct ocfs2_super *osb,
 319					  struct ocfs2_group_desc *bg,
 320					  struct ocfs2_chain_list *cl,
 321					  u64 p_blkno, unsigned int clusters)
 322{
 323	struct ocfs2_extent_list *el = &bg->bg_list;
 324	struct ocfs2_extent_rec *rec;
 325
 326	BUG_ON(!ocfs2_supports_discontig_bg(osb));
 327	if (!el->l_next_free_rec)
 328		el->l_count = cpu_to_le16(ocfs2_extent_recs_per_gd(osb->sb));
 329	rec = &el->l_recs[le16_to_cpu(el->l_next_free_rec)];
 330	rec->e_blkno = cpu_to_le64(p_blkno);
 331	rec->e_cpos = cpu_to_le32(le16_to_cpu(bg->bg_bits) /
 332				  le16_to_cpu(cl->cl_bpc));
 333	rec->e_leaf_clusters = cpu_to_le16(clusters);
 334	le16_add_cpu(&bg->bg_bits, clusters * le16_to_cpu(cl->cl_bpc));
 335	le16_add_cpu(&bg->bg_free_bits_count,
 336		     clusters * le16_to_cpu(cl->cl_bpc));
 337	le16_add_cpu(&el->l_next_free_rec, 1);
 338}
 339
 340static int ocfs2_block_group_fill(handle_t *handle,
 341				  struct inode *alloc_inode,
 342				  struct buffer_head *bg_bh,
 343				  u64 group_blkno,
 344				  unsigned int group_clusters,
 345				  u16 my_chain,
 346				  struct ocfs2_chain_list *cl)
 347{
 348	int status = 0;
 349	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 350	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 351	struct super_block * sb = alloc_inode->i_sb;
 352
 353	if (((unsigned long long) bg_bh->b_blocknr) != group_blkno) {
 354		status = ocfs2_error(alloc_inode->i_sb,
 355				     "group block (%llu) != b_blocknr (%llu)\n",
 356				     (unsigned long long)group_blkno,
 357				     (unsigned long long) bg_bh->b_blocknr);
 358		goto bail;
 359	}
 360
 361	status = ocfs2_journal_access_gd(handle,
 362					 INODE_CACHE(alloc_inode),
 363					 bg_bh,
 364					 OCFS2_JOURNAL_ACCESS_CREATE);
 365	if (status < 0) {
 366		mlog_errno(status);
 367		goto bail;
 368	}
 369
 370	memset(bg, 0, sb->s_blocksize);
 371	strcpy(bg->bg_signature, OCFS2_GROUP_DESC_SIGNATURE);
 372	bg->bg_generation = cpu_to_le32(osb->fs_generation);
 373	bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb, 1,
 374						osb->s_feature_incompat));
 375	bg->bg_chain = cpu_to_le16(my_chain);
 376	bg->bg_next_group = cl->cl_recs[my_chain].c_blkno;
 377	bg->bg_parent_dinode = cpu_to_le64(OCFS2_I(alloc_inode)->ip_blkno);
 378	bg->bg_blkno = cpu_to_le64(group_blkno);
 379	if (group_clusters == le16_to_cpu(cl->cl_cpg))
 380		bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
 381	else
 382		ocfs2_bg_discontig_add_extent(osb, bg, cl, group_blkno,
 383					      group_clusters);
 384
 385	/* set the 1st bit in the bitmap to account for the descriptor block */
 386	ocfs2_set_bit(0, (unsigned long *)bg->bg_bitmap);
 387	bg->bg_free_bits_count = cpu_to_le16(le16_to_cpu(bg->bg_bits) - 1);
 388
 389	ocfs2_journal_dirty(handle, bg_bh);
 390
 391	/* There is no need to zero out or otherwise initialize the
 392	 * other blocks in a group - All valid FS metadata in a block
 393	 * group stores the superblock fs_generation value at
 394	 * allocation time. */
 395
 396bail:
 397	if (status)
 398		mlog_errno(status);
 399	return status;
 400}
 401
 402static inline u16 ocfs2_find_smallest_chain(struct ocfs2_chain_list *cl)
 403{
 404	u16 curr, best;
 405
 406	best = curr = 0;
 407	while (curr < le16_to_cpu(cl->cl_count)) {
 408		if (le32_to_cpu(cl->cl_recs[best].c_total) >
 409		    le32_to_cpu(cl->cl_recs[curr].c_total))
 410			best = curr;
 411		curr++;
 412	}
 413	return best;
 414}
 415
 416static struct buffer_head *
 417ocfs2_block_group_alloc_contig(struct ocfs2_super *osb, handle_t *handle,
 418			       struct inode *alloc_inode,
 419			       struct ocfs2_alloc_context *ac,
 420			       struct ocfs2_chain_list *cl)
 421{
 422	int status;
 423	u32 bit_off, num_bits;
 424	u64 bg_blkno;
 425	struct buffer_head *bg_bh;
 426	unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
 427
 428	status = ocfs2_claim_clusters(handle, ac,
 429				      le16_to_cpu(cl->cl_cpg), &bit_off,
 430				      &num_bits);
 431	if (status < 0) {
 432		if (status != -ENOSPC)
 433			mlog_errno(status);
 434		goto bail;
 435	}
 436
 437	/* setup the group */
 438	bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 439	trace_ocfs2_block_group_alloc_contig(
 440	     (unsigned long long)bg_blkno, alloc_rec);
 441
 442	bg_bh = sb_getblk(osb->sb, bg_blkno);
 443	if (!bg_bh) {
 444		status = -ENOMEM;
 445		mlog_errno(status);
 446		goto bail;
 447	}
 448	ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
 449
 450	status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
 451					bg_blkno, num_bits, alloc_rec, cl);
 452	if (status < 0) {
 453		brelse(bg_bh);
 454		mlog_errno(status);
 455	}
 456
 457bail:
 458	return status ? ERR_PTR(status) : bg_bh;
 459}
 460
 461static int ocfs2_block_group_claim_bits(struct ocfs2_super *osb,
 462					handle_t *handle,
 463					struct ocfs2_alloc_context *ac,
 464					unsigned int min_bits,
 465					u32 *bit_off, u32 *num_bits)
 466{
 467	int status = 0;
 468
 469	while (min_bits) {
 470		status = ocfs2_claim_clusters(handle, ac, min_bits,
 471					      bit_off, num_bits);
 472		if (status != -ENOSPC)
 473			break;
 474
 475		min_bits >>= 1;
 476	}
 477
 478	return status;
 479}
 480
 481static int ocfs2_block_group_grow_discontig(handle_t *handle,
 482					    struct inode *alloc_inode,
 483					    struct buffer_head *bg_bh,
 484					    struct ocfs2_alloc_context *ac,
 485					    struct ocfs2_chain_list *cl,
 486					    unsigned int min_bits)
 487{
 488	int status;
 489	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 490	struct ocfs2_group_desc *bg =
 491		(struct ocfs2_group_desc *)bg_bh->b_data;
 492	unsigned int needed = le16_to_cpu(cl->cl_cpg) -
 493			 le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
 494	u32 p_cpos, clusters;
 495	u64 p_blkno;
 496	struct ocfs2_extent_list *el = &bg->bg_list;
 497
 498	status = ocfs2_journal_access_gd(handle,
 499					 INODE_CACHE(alloc_inode),
 500					 bg_bh,
 501					 OCFS2_JOURNAL_ACCESS_CREATE);
 502	if (status < 0) {
 503		mlog_errno(status);
 504		goto bail;
 505	}
 506
 507	while ((needed > 0) && (le16_to_cpu(el->l_next_free_rec) <
 508				le16_to_cpu(el->l_count))) {
 509		if (min_bits > needed)
 510			min_bits = needed;
 511		status = ocfs2_block_group_claim_bits(osb, handle, ac,
 512						      min_bits, &p_cpos,
 513						      &clusters);
 514		if (status < 0) {
 515			if (status != -ENOSPC)
 516				mlog_errno(status);
 517			goto bail;
 518		}
 519		p_blkno = ocfs2_clusters_to_blocks(osb->sb, p_cpos);
 520		ocfs2_bg_discontig_add_extent(osb, bg, cl, p_blkno,
 521					      clusters);
 522
 523		min_bits = clusters;
 524		needed = le16_to_cpu(cl->cl_cpg) -
 525			 le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
 526	}
 527
 528	if (needed > 0) {
 529		/*
 530		 * We have used up all the extent rec but can't fill up
 531		 * the cpg. So bail out.
 532		 */
 533		status = -ENOSPC;
 534		goto bail;
 535	}
 536
 537	ocfs2_journal_dirty(handle, bg_bh);
 538
 539bail:
 540	return status;
 541}
 542
 543static void ocfs2_bg_alloc_cleanup(handle_t *handle,
 544				   struct ocfs2_alloc_context *cluster_ac,
 545				   struct inode *alloc_inode,
 546				   struct buffer_head *bg_bh)
 547{
 548	int i, ret;
 549	struct ocfs2_group_desc *bg;
 550	struct ocfs2_extent_list *el;
 551	struct ocfs2_extent_rec *rec;
 552
 553	if (!bg_bh)
 554		return;
 555
 556	bg = (struct ocfs2_group_desc *)bg_bh->b_data;
 557	el = &bg->bg_list;
 558	for (i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
 559		rec = &el->l_recs[i];
 560		ret = ocfs2_free_clusters(handle, cluster_ac->ac_inode,
 561					  cluster_ac->ac_bh,
 562					  le64_to_cpu(rec->e_blkno),
 563					  le16_to_cpu(rec->e_leaf_clusters));
 564		if (ret)
 565			mlog_errno(ret);
 566		/* Try all the clusters to free */
 567	}
 568
 569	ocfs2_remove_from_cache(INODE_CACHE(alloc_inode), bg_bh);
 570	brelse(bg_bh);
 571}
 572
 573static struct buffer_head *
 574ocfs2_block_group_alloc_discontig(handle_t *handle,
 575				  struct inode *alloc_inode,
 576				  struct ocfs2_alloc_context *ac,
 577				  struct ocfs2_chain_list *cl)
 578{
 579	int status;
 580	u32 bit_off, num_bits;
 581	u64 bg_blkno;
 582	unsigned int min_bits = le16_to_cpu(cl->cl_cpg) >> 1;
 583	struct buffer_head *bg_bh = NULL;
 584	unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
 585	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 586
 587	if (!ocfs2_supports_discontig_bg(osb)) {
 588		status = -ENOSPC;
 589		goto bail;
 590	}
 591
 592	status = ocfs2_extend_trans(handle,
 593				    ocfs2_calc_bg_discontig_credits(osb->sb));
 594	if (status) {
 595		mlog_errno(status);
 596		goto bail;
 597	}
 598
 599	/*
 600	 * We're going to be grabbing from multiple cluster groups.
 601	 * We don't have enough credits to relink them all, and the
 602	 * cluster groups will be staying in cache for the duration of
 603	 * this operation.
 604	 */
 605	ac->ac_disable_chain_relink = 1;
 606
 607	/* Claim the first region */
 608	status = ocfs2_block_group_claim_bits(osb, handle, ac, min_bits,
 609					      &bit_off, &num_bits);
 610	if (status < 0) {
 611		if (status != -ENOSPC)
 612			mlog_errno(status);
 613		goto bail;
 614	}
 615	min_bits = num_bits;
 616
 617	/* setup the group */
 618	bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 619	trace_ocfs2_block_group_alloc_discontig(
 620				(unsigned long long)bg_blkno, alloc_rec);
 621
 622	bg_bh = sb_getblk(osb->sb, bg_blkno);
 623	if (!bg_bh) {
 624		status = -ENOMEM;
 625		mlog_errno(status);
 626		goto bail;
 627	}
 628	ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
 629
 630	status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
 631					bg_blkno, num_bits, alloc_rec, cl);
 632	if (status < 0) {
 633		mlog_errno(status);
 634		goto bail;
 635	}
 636
 637	status = ocfs2_block_group_grow_discontig(handle, alloc_inode,
 638						  bg_bh, ac, cl, min_bits);
 639	if (status)
 640		mlog_errno(status);
 641
 642bail:
 643	if (status)
 644		ocfs2_bg_alloc_cleanup(handle, ac, alloc_inode, bg_bh);
 645	return status ? ERR_PTR(status) : bg_bh;
 646}
 647
 648/*
 649 * We expect the block group allocator to already be locked.
 650 */
 651static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
 652				   struct inode *alloc_inode,
 653				   struct buffer_head *bh,
 654				   u64 max_block,
 655				   u64 *last_alloc_group,
 656				   int flags)
 657{
 658	int status, credits;
 659	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) bh->b_data;
 660	struct ocfs2_chain_list *cl;
 661	struct ocfs2_alloc_context *ac = NULL;
 662	handle_t *handle = NULL;
 663	u16 alloc_rec;
 664	struct buffer_head *bg_bh = NULL;
 665	struct ocfs2_group_desc *bg;
 666
 667	BUG_ON(ocfs2_is_cluster_bitmap(alloc_inode));
 668
 669	cl = &fe->id2.i_chain;
 670	status = ocfs2_reserve_clusters_with_limit(osb,
 671						   le16_to_cpu(cl->cl_cpg),
 672						   max_block, flags, &ac);
 673	if (status < 0) {
 674		if (status != -ENOSPC)
 675			mlog_errno(status);
 676		goto bail;
 677	}
 678
 679	credits = ocfs2_calc_group_alloc_credits(osb->sb,
 680						 le16_to_cpu(cl->cl_cpg));
 681	handle = ocfs2_start_trans(osb, credits);
 682	if (IS_ERR(handle)) {
 683		status = PTR_ERR(handle);
 684		handle = NULL;
 685		mlog_errno(status);
 686		goto bail;
 687	}
 688
 689	if (last_alloc_group && *last_alloc_group != 0) {
 690		trace_ocfs2_block_group_alloc(
 691				(unsigned long long)*last_alloc_group);
 692		ac->ac_last_group = *last_alloc_group;
 693	}
 694
 695	bg_bh = ocfs2_block_group_alloc_contig(osb, handle, alloc_inode,
 696					       ac, cl);
 697	if (PTR_ERR(bg_bh) == -ENOSPC)
 698		bg_bh = ocfs2_block_group_alloc_discontig(handle,
 699							  alloc_inode,
 700							  ac, cl);
 701	if (IS_ERR(bg_bh)) {
 702		status = PTR_ERR(bg_bh);
 703		bg_bh = NULL;
 704		if (status != -ENOSPC)
 705			mlog_errno(status);
 706		goto bail;
 707	}
 708	bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 709
 710	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
 711					 bh, OCFS2_JOURNAL_ACCESS_WRITE);
 712	if (status < 0) {
 713		mlog_errno(status);
 714		goto bail;
 715	}
 716
 717	alloc_rec = le16_to_cpu(bg->bg_chain);
 718	le32_add_cpu(&cl->cl_recs[alloc_rec].c_free,
 719		     le16_to_cpu(bg->bg_free_bits_count));
 720	le32_add_cpu(&cl->cl_recs[alloc_rec].c_total,
 721		     le16_to_cpu(bg->bg_bits));
 722	cl->cl_recs[alloc_rec].c_blkno = bg->bg_blkno;
 723	if (le16_to_cpu(cl->cl_next_free_rec) < le16_to_cpu(cl->cl_count))
 724		le16_add_cpu(&cl->cl_next_free_rec, 1);
 725
 726	le32_add_cpu(&fe->id1.bitmap1.i_used, le16_to_cpu(bg->bg_bits) -
 727					le16_to_cpu(bg->bg_free_bits_count));
 728	le32_add_cpu(&fe->id1.bitmap1.i_total, le16_to_cpu(bg->bg_bits));
 729	le32_add_cpu(&fe->i_clusters, le16_to_cpu(cl->cl_cpg));
 730
 731	ocfs2_journal_dirty(handle, bh);
 732
 733	spin_lock(&OCFS2_I(alloc_inode)->ip_lock);
 734	OCFS2_I(alloc_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
 735	fe->i_size = cpu_to_le64(ocfs2_clusters_to_bytes(alloc_inode->i_sb,
 736					     le32_to_cpu(fe->i_clusters)));
 737	spin_unlock(&OCFS2_I(alloc_inode)->ip_lock);
 738	i_size_write(alloc_inode, le64_to_cpu(fe->i_size));
 739	alloc_inode->i_blocks = ocfs2_inode_sector_count(alloc_inode);
 740	ocfs2_update_inode_fsync_trans(handle, alloc_inode, 0);
 741
 742	status = 0;
 743
 744	/* save the new last alloc group so that the caller can cache it. */
 745	if (last_alloc_group)
 746		*last_alloc_group = ac->ac_last_group;
 747
 748bail:
 749	if (handle)
 750		ocfs2_commit_trans(osb, handle);
 751
 752	if (ac)
 753		ocfs2_free_alloc_context(ac);
 754
 755	brelse(bg_bh);
 756
 757	if (status)
 758		mlog_errno(status);
 759	return status;
 760}
 761
 762static int ocfs2_reserve_suballoc_bits(struct ocfs2_super *osb,
 763				       struct ocfs2_alloc_context *ac,
 764				       int type,
 765				       u32 slot,
 766				       u64 *last_alloc_group,
 767				       int flags)
 768{
 769	int status;
 770	u32 bits_wanted = ac->ac_bits_wanted;
 771	struct inode *alloc_inode;
 772	struct buffer_head *bh = NULL;
 773	struct ocfs2_dinode *fe;
 774	u32 free_bits;
 775
 776	alloc_inode = ocfs2_get_system_file_inode(osb, type, slot);
 777	if (!alloc_inode) {
 778		mlog_errno(-EINVAL);
 779		return -EINVAL;
 780	}
 781
 782	inode_lock(alloc_inode);
 783
 784	status = ocfs2_inode_lock(alloc_inode, &bh, 1);
 785	if (status < 0) {
 786		inode_unlock(alloc_inode);
 787		iput(alloc_inode);
 788
 789		mlog_errno(status);
 790		return status;
 791	}
 792
 793	ac->ac_inode = alloc_inode;
 794	ac->ac_alloc_slot = slot;
 795
 796	fe = (struct ocfs2_dinode *) bh->b_data;
 797
 798	/* The bh was validated by the inode read inside
 799	 * ocfs2_inode_lock().  Any corruption is a code bug. */
 800	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
 801
 802	if (!(fe->i_flags & cpu_to_le32(OCFS2_CHAIN_FL))) {
 803		status = ocfs2_error(alloc_inode->i_sb,
 804				     "Invalid chain allocator %llu\n",
 805				     (unsigned long long)le64_to_cpu(fe->i_blkno));
 806		goto bail;
 807	}
 808
 809	free_bits = le32_to_cpu(fe->id1.bitmap1.i_total) -
 810		le32_to_cpu(fe->id1.bitmap1.i_used);
 811
 812	if (bits_wanted > free_bits) {
 813		/* cluster bitmap never grows */
 814		if (ocfs2_is_cluster_bitmap(alloc_inode)) {
 815			trace_ocfs2_reserve_suballoc_bits_nospc(bits_wanted,
 816								free_bits);
 817			status = -ENOSPC;
 818			goto bail;
 819		}
 820
 821		if (!(flags & ALLOC_NEW_GROUP)) {
 822			trace_ocfs2_reserve_suballoc_bits_no_new_group(
 823						slot, bits_wanted, free_bits);
 824			status = -ENOSPC;
 825			goto bail;
 826		}
 827
 828		status = ocfs2_block_group_alloc(osb, alloc_inode, bh,
 829						 ac->ac_max_block,
 830						 last_alloc_group, flags);
 831		if (status < 0) {
 832			if (status != -ENOSPC)
 833				mlog_errno(status);
 834			goto bail;
 835		}
 836		atomic_inc(&osb->alloc_stats.bg_extends);
 837
 838		/* You should never ask for this much metadata */
 839		BUG_ON(bits_wanted >
 840		       (le32_to_cpu(fe->id1.bitmap1.i_total)
 841			- le32_to_cpu(fe->id1.bitmap1.i_used)));
 842	}
 843
 844	get_bh(bh);
 845	ac->ac_bh = bh;
 846bail:
 847	brelse(bh);
 848
 849	if (status)
 850		mlog_errno(status);
 851	return status;
 852}
 853
 854static void ocfs2_init_inode_steal_slot(struct ocfs2_super *osb)
 855{
 856	spin_lock(&osb->osb_lock);
 857	osb->s_inode_steal_slot = OCFS2_INVALID_SLOT;
 858	spin_unlock(&osb->osb_lock);
 859	atomic_set(&osb->s_num_inodes_stolen, 0);
 860}
 861
 862static void ocfs2_init_meta_steal_slot(struct ocfs2_super *osb)
 863{
 864	spin_lock(&osb->osb_lock);
 865	osb->s_meta_steal_slot = OCFS2_INVALID_SLOT;
 866	spin_unlock(&osb->osb_lock);
 867	atomic_set(&osb->s_num_meta_stolen, 0);
 868}
 869
 870void ocfs2_init_steal_slots(struct ocfs2_super *osb)
 871{
 872	ocfs2_init_inode_steal_slot(osb);
 873	ocfs2_init_meta_steal_slot(osb);
 874}
 875
 876static void __ocfs2_set_steal_slot(struct ocfs2_super *osb, int slot, int type)
 877{
 878	spin_lock(&osb->osb_lock);
 879	if (type == INODE_ALLOC_SYSTEM_INODE)
 880		osb->s_inode_steal_slot = (u16)slot;
 881	else if (type == EXTENT_ALLOC_SYSTEM_INODE)
 882		osb->s_meta_steal_slot = (u16)slot;
 883	spin_unlock(&osb->osb_lock);
 884}
 885
 886static int __ocfs2_get_steal_slot(struct ocfs2_super *osb, int type)
 887{
 888	int slot = OCFS2_INVALID_SLOT;
 889
 890	spin_lock(&osb->osb_lock);
 891	if (type == INODE_ALLOC_SYSTEM_INODE)
 892		slot = osb->s_inode_steal_slot;
 893	else if (type == EXTENT_ALLOC_SYSTEM_INODE)
 894		slot = osb->s_meta_steal_slot;
 895	spin_unlock(&osb->osb_lock);
 896
 897	return slot;
 898}
 899
 900static int ocfs2_get_inode_steal_slot(struct ocfs2_super *osb)
 901{
 902	return __ocfs2_get_steal_slot(osb, INODE_ALLOC_SYSTEM_INODE);
 903}
 904
 905static int ocfs2_get_meta_steal_slot(struct ocfs2_super *osb)
 906{
 907	return __ocfs2_get_steal_slot(osb, EXTENT_ALLOC_SYSTEM_INODE);
 908}
 909
 910static int ocfs2_steal_resource(struct ocfs2_super *osb,
 911				struct ocfs2_alloc_context *ac,
 912				int type)
 913{
 914	int i, status = -ENOSPC;
 915	int slot = __ocfs2_get_steal_slot(osb, type);
 916
 917	/* Start to steal resource from the first slot after ours. */
 918	if (slot == OCFS2_INVALID_SLOT)
 919		slot = osb->slot_num + 1;
 920
 921	for (i = 0; i < osb->max_slots; i++, slot++) {
 922		if (slot == osb->max_slots)
 923			slot = 0;
 924
 925		if (slot == osb->slot_num)
 926			continue;
 927
 928		status = ocfs2_reserve_suballoc_bits(osb, ac,
 929						     type,
 930						     (u32)slot, NULL,
 931						     NOT_ALLOC_NEW_GROUP);
 932		if (status >= 0) {
 933			__ocfs2_set_steal_slot(osb, slot, type);
 934			break;
 935		}
 936
 937		ocfs2_free_ac_resource(ac);
 938	}
 939
 940	return status;
 941}
 942
 943static int ocfs2_steal_inode(struct ocfs2_super *osb,
 944			     struct ocfs2_alloc_context *ac)
 945{
 946	return ocfs2_steal_resource(osb, ac, INODE_ALLOC_SYSTEM_INODE);
 947}
 948
 949static int ocfs2_steal_meta(struct ocfs2_super *osb,
 950			    struct ocfs2_alloc_context *ac)
 951{
 952	return ocfs2_steal_resource(osb, ac, EXTENT_ALLOC_SYSTEM_INODE);
 953}
 954
 955int ocfs2_reserve_new_metadata_blocks(struct ocfs2_super *osb,
 956				      int blocks,
 957				      struct ocfs2_alloc_context **ac)
 958{
 959	int status;
 960	int slot = ocfs2_get_meta_steal_slot(osb);
 961
 962	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 963	if (!(*ac)) {
 964		status = -ENOMEM;
 965		mlog_errno(status);
 966		goto bail;
 967	}
 968
 969	(*ac)->ac_bits_wanted = blocks;
 970	(*ac)->ac_which = OCFS2_AC_USE_META;
 971	(*ac)->ac_group_search = ocfs2_block_group_search;
 972
 973	if (slot != OCFS2_INVALID_SLOT &&
 974		atomic_read(&osb->s_num_meta_stolen) < OCFS2_MAX_TO_STEAL)
 975		goto extent_steal;
 976
 977	atomic_set(&osb->s_num_meta_stolen, 0);
 978	status = ocfs2_reserve_suballoc_bits(osb, (*ac),
 979					     EXTENT_ALLOC_SYSTEM_INODE,
 980					     (u32)osb->slot_num, NULL,
 981					     ALLOC_GROUPS_FROM_GLOBAL|ALLOC_NEW_GROUP);
 982
 983
 984	if (status >= 0) {
 985		status = 0;
 986		if (slot != OCFS2_INVALID_SLOT)
 987			ocfs2_init_meta_steal_slot(osb);
 988		goto bail;
 989	} else if (status < 0 && status != -ENOSPC) {
 990		mlog_errno(status);
 991		goto bail;
 992	}
 993
 994	ocfs2_free_ac_resource(*ac);
 995
 996extent_steal:
 997	status = ocfs2_steal_meta(osb, *ac);
 998	atomic_inc(&osb->s_num_meta_stolen);
 999	if (status < 0) {
1000		if (status != -ENOSPC)
1001			mlog_errno(status);
1002		goto bail;
1003	}
1004
1005	status = 0;
1006bail:
1007	if ((status < 0) && *ac) {
1008		ocfs2_free_alloc_context(*ac);
1009		*ac = NULL;
1010	}
1011
1012	if (status)
1013		mlog_errno(status);
1014	return status;
1015}
1016
1017int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
1018			       struct ocfs2_extent_list *root_el,
1019			       struct ocfs2_alloc_context **ac)
1020{
1021	return ocfs2_reserve_new_metadata_blocks(osb,
1022					ocfs2_extend_meta_needed(root_el),
1023					ac);
1024}
1025
1026int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
1027			    struct ocfs2_alloc_context **ac)
1028{
1029	int status;
1030	int slot = ocfs2_get_inode_steal_slot(osb);
1031	u64 alloc_group;
1032
1033	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1034	if (!(*ac)) {
1035		status = -ENOMEM;
1036		mlog_errno(status);
1037		goto bail;
1038	}
1039
1040	(*ac)->ac_bits_wanted = 1;
1041	(*ac)->ac_which = OCFS2_AC_USE_INODE;
1042
1043	(*ac)->ac_group_search = ocfs2_block_group_search;
1044
1045	/*
1046	 * stat(2) can't handle i_ino > 32bits, so we tell the
1047	 * lower levels not to allocate us a block group past that
1048	 * limit.  The 'inode64' mount option avoids this behavior.
1049	 */
1050	if (!(osb->s_mount_opt & OCFS2_MOUNT_INODE64))
1051		(*ac)->ac_max_block = (u32)~0U;
1052
1053	/*
1054	 * slot is set when we successfully steal inode from other nodes.
1055	 * It is reset in 3 places:
1056	 * 1. when we flush the truncate log
1057	 * 2. when we complete local alloc recovery.
1058	 * 3. when we successfully allocate from our own slot.
1059	 * After it is set, we will go on stealing inodes until we find the
1060	 * need to check our slots to see whether there is some space for us.
1061	 */
1062	if (slot != OCFS2_INVALID_SLOT &&
1063	    atomic_read(&osb->s_num_inodes_stolen) < OCFS2_MAX_TO_STEAL)
1064		goto inode_steal;
1065
1066	atomic_set(&osb->s_num_inodes_stolen, 0);
1067	alloc_group = osb->osb_inode_alloc_group;
1068	status = ocfs2_reserve_suballoc_bits(osb, *ac,
1069					     INODE_ALLOC_SYSTEM_INODE,
1070					     (u32)osb->slot_num,
1071					     &alloc_group,
1072					     ALLOC_NEW_GROUP |
1073					     ALLOC_GROUPS_FROM_GLOBAL);
1074	if (status >= 0) {
1075		status = 0;
1076
1077		spin_lock(&osb->osb_lock);
1078		osb->osb_inode_alloc_group = alloc_group;
1079		spin_unlock(&osb->osb_lock);
1080		trace_ocfs2_reserve_new_inode_new_group(
1081			(unsigned long long)alloc_group);
1082
1083		/*
1084		 * Some inodes must be freed by us, so try to allocate
1085		 * from our own next time.
1086		 */
1087		if (slot != OCFS2_INVALID_SLOT)
1088			ocfs2_init_inode_steal_slot(osb);
1089		goto bail;
1090	} else if (status < 0 && status != -ENOSPC) {
1091		mlog_errno(status);
1092		goto bail;
1093	}
1094
1095	ocfs2_free_ac_resource(*ac);
1096
1097inode_steal:
1098	status = ocfs2_steal_inode(osb, *ac);
1099	atomic_inc(&osb->s_num_inodes_stolen);
1100	if (status < 0) {
1101		if (status != -ENOSPC)
1102			mlog_errno(status);
1103		goto bail;
1104	}
1105
1106	status = 0;
1107bail:
1108	if ((status < 0) && *ac) {
1109		ocfs2_free_alloc_context(*ac);
1110		*ac = NULL;
1111	}
1112
1113	if (status)
1114		mlog_errno(status);
1115	return status;
1116}
1117
1118/* local alloc code has to do the same thing, so rather than do this
1119 * twice.. */
1120int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
1121				      struct ocfs2_alloc_context *ac)
1122{
1123	int status;
1124
1125	ac->ac_which = OCFS2_AC_USE_MAIN;
1126	ac->ac_group_search = ocfs2_cluster_group_search;
1127
1128	status = ocfs2_reserve_suballoc_bits(osb, ac,
1129					     GLOBAL_BITMAP_SYSTEM_INODE,
1130					     OCFS2_INVALID_SLOT, NULL,
1131					     ALLOC_NEW_GROUP);
1132	if (status < 0 && status != -ENOSPC)
1133		mlog_errno(status);
1134
1135	return status;
1136}
1137
1138/* Callers don't need to care which bitmap (local alloc or main) to
1139 * use so we figure it out for them, but unfortunately this clutters
1140 * things a bit. */
1141static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
1142					     u32 bits_wanted, u64 max_block,
1143					     int flags,
1144					     struct ocfs2_alloc_context **ac)
1145{
1146	int status, ret = 0;
1147	int retried = 0;
1148
1149	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1150	if (!(*ac)) {
1151		status = -ENOMEM;
1152		mlog_errno(status);
1153		goto bail;
1154	}
1155
1156	(*ac)->ac_bits_wanted = bits_wanted;
1157	(*ac)->ac_max_block = max_block;
1158
1159	status = -ENOSPC;
1160	if (!(flags & ALLOC_GROUPS_FROM_GLOBAL) &&
1161	    ocfs2_alloc_should_use_local(osb, bits_wanted)) {
1162		status = ocfs2_reserve_local_alloc_bits(osb,
1163							bits_wanted,
1164							*ac);
1165		if ((status < 0) && (status != -ENOSPC)) {
1166			mlog_errno(status);
1167			goto bail;
1168		}
1169	}
1170
1171	if (status == -ENOSPC) {
1172retry:
1173		status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
1174		/* Retry if there is sufficient space cached in truncate log */
1175		if (status == -ENOSPC && !retried) {
1176			retried = 1;
1177			ocfs2_inode_unlock((*ac)->ac_inode, 1);
1178			inode_unlock((*ac)->ac_inode);
1179
1180			ret = ocfs2_try_to_free_truncate_log(osb, bits_wanted);
1181			if (ret == 1) {
1182				iput((*ac)->ac_inode);
1183				(*ac)->ac_inode = NULL;
1184				goto retry;
1185			}
1186
1187			if (ret < 0)
1188				mlog_errno(ret);
1189
1190			inode_lock((*ac)->ac_inode);
1191			ret = ocfs2_inode_lock((*ac)->ac_inode, NULL, 1);
1192			if (ret < 0) {
1193				mlog_errno(ret);
1194				inode_unlock((*ac)->ac_inode);
1195				iput((*ac)->ac_inode);
1196				(*ac)->ac_inode = NULL;
1197				goto bail;
1198			}
1199		}
1200		if (status < 0) {
1201			if (status != -ENOSPC)
1202				mlog_errno(status);
1203			goto bail;
1204		}
1205	}
1206
1207	status = 0;
1208bail:
1209	if ((status < 0) && *ac) {
1210		ocfs2_free_alloc_context(*ac);
1211		*ac = NULL;
1212	}
1213
1214	if (status)
1215		mlog_errno(status);
1216	return status;
1217}
1218
1219int ocfs2_reserve_clusters(struct ocfs2_super *osb,
1220			   u32 bits_wanted,
1221			   struct ocfs2_alloc_context **ac)
1222{
1223	return ocfs2_reserve_clusters_with_limit(osb, bits_wanted, 0,
1224						 ALLOC_NEW_GROUP, ac);
1225}
1226
1227/*
1228 * More or less lifted from ext3. I'll leave their description below:
1229 *
1230 * "For ext3 allocations, we must not reuse any blocks which are
1231 * allocated in the bitmap buffer's "last committed data" copy.  This
1232 * prevents deletes from freeing up the page for reuse until we have
1233 * committed the delete transaction.
1234 *
1235 * If we didn't do this, then deleting something and reallocating it as
1236 * data would allow the old block to be overwritten before the
1237 * transaction committed (because we force data to disk before commit).
1238 * This would lead to corruption if we crashed between overwriting the
1239 * data and committing the delete.
1240 *
1241 * @@@ We may want to make this allocation behaviour conditional on
1242 * data-writes at some point, and disable it for metadata allocations or
1243 * sync-data inodes."
1244 *
1245 * Note: OCFS2 already does this differently for metadata vs data
1246 * allocations, as those bitmaps are separate and undo access is never
1247 * called on a metadata group descriptor.
1248 */
1249static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
1250					 int nr)
1251{
1252	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1253	struct journal_head *jh;
1254	int ret;
1255
1256	if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
1257		return 0;
1258
1259	jh = jbd2_journal_grab_journal_head(bg_bh);
1260	if (!jh)
1261		return 1;
1262
1263	spin_lock(&jh->b_state_lock);
1264	bg = (struct ocfs2_group_desc *) jh->b_committed_data;
1265	if (bg)
1266		ret = !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
1267	else
1268		ret = 1;
1269	spin_unlock(&jh->b_state_lock);
1270	jbd2_journal_put_journal_head(jh);
1271
1272	return ret;
1273}
1274
1275static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
1276					     struct buffer_head *bg_bh,
1277					     unsigned int bits_wanted,
1278					     unsigned int total_bits,
1279					     struct ocfs2_suballoc_result *res)
1280{
1281	void *bitmap;
1282	u16 best_offset, best_size;
1283	int offset, start, found, status = 0;
1284	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1285
1286	/* Callers got this descriptor from
1287	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1288	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1289
1290	found = start = best_offset = best_size = 0;
1291	bitmap = bg->bg_bitmap;
1292
1293	while((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) != -1) {
1294		if (offset == total_bits)
1295			break;
1296
1297		if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
1298			/* We found a zero, but we can't use it as it
1299			 * hasn't been put to disk yet! */
1300			found = 0;
1301			start = offset + 1;
1302		} else if (offset == start) {
1303			/* we found a zero */
1304			found++;
1305			/* move start to the next bit to test */
1306			start++;
1307		} else {
1308			/* got a zero after some ones */
1309			found = 1;
1310			start = offset + 1;
1311		}
1312		if (found > best_size) {
1313			best_size = found;
1314			best_offset = start - found;
1315		}
1316		/* we got everything we needed */
1317		if (found == bits_wanted) {
1318			/* mlog(0, "Found it all!\n"); */
1319			break;
1320		}
1321	}
1322
1323	if (best_size) {
1324		res->sr_bit_offset = best_offset;
1325		res->sr_bits = best_size;
1326	} else {
1327		status = -ENOSPC;
1328		/* No error log here -- see the comment above
1329		 * ocfs2_test_bg_bit_allocatable */
1330	}
1331
1332	return status;
1333}
1334
1335int ocfs2_block_group_set_bits(handle_t *handle,
1336					     struct inode *alloc_inode,
1337					     struct ocfs2_group_desc *bg,
1338					     struct buffer_head *group_bh,
1339					     unsigned int bit_off,
1340					     unsigned int num_bits)
1341{
1342	int status;
1343	void *bitmap = bg->bg_bitmap;
1344	int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1345
1346	/* All callers get the descriptor via
1347	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1348	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1349	BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
1350
1351	trace_ocfs2_block_group_set_bits(bit_off, num_bits);
1352
1353	if (ocfs2_is_cluster_bitmap(alloc_inode))
1354		journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1355
1356	status = ocfs2_journal_access_gd(handle,
1357					 INODE_CACHE(alloc_inode),
1358					 group_bh,
1359					 journal_type);
1360	if (status < 0) {
1361		mlog_errno(status);
1362		goto bail;
1363	}
1364
1365	le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
1366	if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
1367		return ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit count %u but claims %u are freed. num_bits %d\n",
1368				   (unsigned long long)le64_to_cpu(bg->bg_blkno),
1369				   le16_to_cpu(bg->bg_bits),
1370				   le16_to_cpu(bg->bg_free_bits_count),
1371				   num_bits);
1372	}
1373	while(num_bits--)
1374		ocfs2_set_bit(bit_off++, bitmap);
1375
1376	ocfs2_journal_dirty(handle, group_bh);
1377
1378bail:
1379	return status;
1380}
1381
1382/* find the one with the most empty bits */
1383static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
1384{
1385	u16 curr, best;
1386
1387	BUG_ON(!cl->cl_next_free_rec);
1388
1389	best = curr = 0;
1390	while (curr < le16_to_cpu(cl->cl_next_free_rec)) {
1391		if (le32_to_cpu(cl->cl_recs[curr].c_free) >
1392		    le32_to_cpu(cl->cl_recs[best].c_free))
1393			best = curr;
1394		curr++;
1395	}
1396
1397	BUG_ON(best >= le16_to_cpu(cl->cl_next_free_rec));
1398	return best;
1399}
1400
1401static int ocfs2_relink_block_group(handle_t *handle,
1402				    struct inode *alloc_inode,
1403				    struct buffer_head *fe_bh,
1404				    struct buffer_head *bg_bh,
1405				    struct buffer_head *prev_bg_bh,
1406				    u16 chain)
1407{
1408	int status;
1409	/* there is a really tiny chance the journal calls could fail,
1410	 * but we wouldn't want inconsistent blocks in *any* case. */
1411	u64 bg_ptr, prev_bg_ptr;
1412	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
1413	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1414	struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
1415
1416	/* The caller got these descriptors from
1417	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1418	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1419	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(prev_bg));
1420
1421	trace_ocfs2_relink_block_group(
1422		(unsigned long long)le64_to_cpu(fe->i_blkno), chain,
1423		(unsigned long long)le64_to_cpu(bg->bg_blkno),
1424		(unsigned long long)le64_to_cpu(prev_bg->bg_blkno));
1425
1426	bg_ptr = le64_to_cpu(bg->bg_next_group);
1427	prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
1428
1429	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1430					 prev_bg_bh,
1431					 OCFS2_JOURNAL_ACCESS_WRITE);
1432	if (status < 0)
1433		goto out;
1434
1435	prev_bg->bg_next_group = bg->bg_next_group;
1436	ocfs2_journal_dirty(handle, prev_bg_bh);
1437
1438	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1439					 bg_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1440	if (status < 0)
1441		goto out_rollback_prev_bg;
1442
1443	bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
1444	ocfs2_journal_dirty(handle, bg_bh);
1445
1446	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
1447					 fe_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1448	if (status < 0)
1449		goto out_rollback_bg;
1450
1451	fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
1452	ocfs2_journal_dirty(handle, fe_bh);
1453
1454out:
1455	if (status < 0)
1456		mlog_errno(status);
1457	return status;
1458
1459out_rollback_bg:
1460	bg->bg_next_group = cpu_to_le64(bg_ptr);
1461out_rollback_prev_bg:
1462	prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
1463	goto out;
1464}
1465
1466static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
1467						     u32 wanted)
1468{
1469	return le16_to_cpu(bg->bg_free_bits_count) > wanted;
1470}
1471
1472/* return 0 on success, -ENOSPC to keep searching and any other < 0
1473 * value on error. */
1474static int ocfs2_cluster_group_search(struct inode *inode,
1475				      struct buffer_head *group_bh,
1476				      u32 bits_wanted, u32 min_bits,
1477				      u64 max_block,
1478				      struct ocfs2_suballoc_result *res)
1479{
1480	int search = -ENOSPC;
1481	int ret;
1482	u64 blkoff;
1483	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
1484	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1485	unsigned int max_bits, gd_cluster_off;
1486
1487	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1488
1489	if (gd->bg_free_bits_count) {
1490		max_bits = le16_to_cpu(gd->bg_bits);
1491
1492		/* Tail groups in cluster bitmaps which aren't cpg
1493		 * aligned are prone to partial extension by a failed
1494		 * fs resize. If the file system resize never got to
1495		 * update the dinode cluster count, then we don't want
1496		 * to trust any clusters past it, regardless of what
1497		 * the group descriptor says. */
1498		gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
1499							  le64_to_cpu(gd->bg_blkno));
1500		if ((gd_cluster_off + max_bits) >
1501		    OCFS2_I(inode)->ip_clusters) {
1502			max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
1503			trace_ocfs2_cluster_group_search_wrong_max_bits(
1504				(unsigned long long)le64_to_cpu(gd->bg_blkno),
1505				le16_to_cpu(gd->bg_bits),
1506				OCFS2_I(inode)->ip_clusters, max_bits);
1507		}
1508
1509		ret = ocfs2_block_group_find_clear_bits(osb,
1510							group_bh, bits_wanted,
1511							max_bits, res);
1512		if (ret)
1513			return ret;
1514
1515		if (max_block) {
1516			blkoff = ocfs2_clusters_to_blocks(inode->i_sb,
1517							  gd_cluster_off +
1518							  res->sr_bit_offset +
1519							  res->sr_bits);
1520			trace_ocfs2_cluster_group_search_max_block(
1521				(unsigned long long)blkoff,
1522				(unsigned long long)max_block);
1523			if (blkoff > max_block)
1524				return -ENOSPC;
1525		}
1526
1527		/* ocfs2_block_group_find_clear_bits() might
1528		 * return success, but we still want to return
1529		 * -ENOSPC unless it found the minimum number
1530		 * of bits. */
1531		if (min_bits <= res->sr_bits)
1532			search = 0; /* success */
1533		else if (res->sr_bits) {
1534			/*
1535			 * Don't show bits which we'll be returning
1536			 * for allocation to the local alloc bitmap.
1537			 */
1538			ocfs2_local_alloc_seen_free_bits(osb, res->sr_bits);
1539		}
1540	}
1541
1542	return search;
1543}
1544
1545static int ocfs2_block_group_search(struct inode *inode,
1546				    struct buffer_head *group_bh,
1547				    u32 bits_wanted, u32 min_bits,
1548				    u64 max_block,
1549				    struct ocfs2_suballoc_result *res)
1550{
1551	int ret = -ENOSPC;
1552	u64 blkoff;
1553	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
1554
1555	BUG_ON(min_bits != 1);
1556	BUG_ON(ocfs2_is_cluster_bitmap(inode));
1557
1558	if (bg->bg_free_bits_count) {
1559		ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1560							group_bh, bits_wanted,
1561							le16_to_cpu(bg->bg_bits),
1562							res);
1563		if (!ret && max_block) {
1564			blkoff = le64_to_cpu(bg->bg_blkno) +
1565				res->sr_bit_offset + res->sr_bits;
1566			trace_ocfs2_block_group_search_max_block(
1567				(unsigned long long)blkoff,
1568				(unsigned long long)max_block);
1569			if (blkoff > max_block)
1570				ret = -ENOSPC;
1571		}
1572	}
1573
1574	return ret;
1575}
1576
1577int ocfs2_alloc_dinode_update_counts(struct inode *inode,
1578				       handle_t *handle,
1579				       struct buffer_head *di_bh,
1580				       u32 num_bits,
1581				       u16 chain)
1582{
1583	int ret;
1584	u32 tmp_used;
1585	struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1586	struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &di->id2.i_chain;
1587
1588	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
1589				      OCFS2_JOURNAL_ACCESS_WRITE);
1590	if (ret < 0) {
1591		mlog_errno(ret);
1592		goto out;
1593	}
1594
1595	tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1596	di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
1597	le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
1598	ocfs2_journal_dirty(handle, di_bh);
1599
1600out:
1601	return ret;
1602}
1603
1604void ocfs2_rollback_alloc_dinode_counts(struct inode *inode,
1605				       struct buffer_head *di_bh,
1606				       u32 num_bits,
1607				       u16 chain)
1608{
1609	u32 tmp_used;
1610	struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1611	struct ocfs2_chain_list *cl;
1612
1613	cl = (struct ocfs2_chain_list *)&di->id2.i_chain;
1614	tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1615	di->id1.bitmap1.i_used = cpu_to_le32(tmp_used - num_bits);
1616	le32_add_cpu(&cl->cl_recs[chain].c_free, num_bits);
1617}
1618
1619static int ocfs2_bg_discontig_fix_by_rec(struct ocfs2_suballoc_result *res,
1620					 struct ocfs2_extent_rec *rec,
1621					 struct ocfs2_chain_list *cl)
1622{
1623	unsigned int bpc = le16_to_cpu(cl->cl_bpc);
1624	unsigned int bitoff = le32_to_cpu(rec->e_cpos) * bpc;
1625	unsigned int bitcount = le16_to_cpu(rec->e_leaf_clusters) * bpc;
1626
1627	if (res->sr_bit_offset < bitoff)
1628		return 0;
1629	if (res->sr_bit_offset >= (bitoff + bitcount))
1630		return 0;
1631	res->sr_blkno = le64_to_cpu(rec->e_blkno) +
1632		(res->sr_bit_offset - bitoff);
1633	if ((res->sr_bit_offset + res->sr_bits) > (bitoff + bitcount))
1634		res->sr_bits = (bitoff + bitcount) - res->sr_bit_offset;
1635	return 1;
1636}
1637
1638static void ocfs2_bg_discontig_fix_result(struct ocfs2_alloc_context *ac,
1639					  struct ocfs2_group_desc *bg,
1640					  struct ocfs2_suballoc_result *res)
1641{
1642	int i;
1643	u64 bg_blkno = res->sr_bg_blkno;  /* Save off */
1644	struct ocfs2_extent_rec *rec;
1645	struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1646	struct ocfs2_chain_list *cl = &di->id2.i_chain;
1647
1648	if (ocfs2_is_cluster_bitmap(ac->ac_inode)) {
1649		res->sr_blkno = 0;
1650		return;
1651	}
1652
1653	res->sr_blkno = res->sr_bg_blkno + res->sr_bit_offset;
1654	res->sr_bg_blkno = 0;  /* Clear it for contig block groups */
1655	if (!ocfs2_supports_discontig_bg(OCFS2_SB(ac->ac_inode->i_sb)) ||
1656	    !bg->bg_list.l_next_free_rec)
1657		return;
1658
1659	for (i = 0; i < le16_to_cpu(bg->bg_list.l_next_free_rec); i++) {
1660		rec = &bg->bg_list.l_recs[i];
1661		if (ocfs2_bg_discontig_fix_by_rec(res, rec, cl)) {
1662			res->sr_bg_blkno = bg_blkno;  /* Restore */
1663			break;
1664		}
1665	}
1666}
1667
1668static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
1669				  handle_t *handle,
1670				  u32 bits_wanted,
1671				  u32 min_bits,
1672				  struct ocfs2_suballoc_result *res,
1673				  u16 *bits_left)
1674{
1675	int ret;
1676	struct buffer_head *group_bh = NULL;
1677	struct ocfs2_group_desc *gd;
1678	struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1679	struct inode *alloc_inode = ac->ac_inode;
1680
1681	ret = ocfs2_read_group_descriptor(alloc_inode, di,
1682					  res->sr_bg_blkno, &group_bh);
1683	if (ret < 0) {
1684		mlog_errno(ret);
1685		return ret;
1686	}
1687
1688	gd = (struct ocfs2_group_desc *) group_bh->b_data;
1689	ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
1690				  ac->ac_max_block, res);
1691	if (ret < 0) {
1692		if (ret != -ENOSPC)
1693			mlog_errno(ret);
1694		goto out;
1695	}
1696
1697	if (!ret)
1698		ocfs2_bg_discontig_fix_result(ac, gd, res);
1699
1700	/*
1701	 * sr_bg_blkno might have been changed by
1702	 * ocfs2_bg_discontig_fix_result
1703	 */
1704	res->sr_bg_stable_blkno = group_bh->b_blocknr;
1705
1706	if (ac->ac_find_loc_only)
1707		goto out_loc_only;
1708
1709	ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
1710					       res->sr_bits,
1711					       le16_to_cpu(gd->bg_chain));
1712	if (ret < 0) {
1713		mlog_errno(ret);
1714		goto out;
1715	}
1716
1717	ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
1718					 res->sr_bit_offset, res->sr_bits);
1719	if (ret < 0) {
1720		ocfs2_rollback_alloc_dinode_counts(alloc_inode, ac->ac_bh,
1721					       res->sr_bits,
1722					       le16_to_cpu(gd->bg_chain));
1723		mlog_errno(ret);
1724	}
1725
1726out_loc_only:
1727	*bits_left = le16_to_cpu(gd->bg_free_bits_count);
1728
1729out:
1730	brelse(group_bh);
1731
1732	return ret;
1733}
1734
1735static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
1736			      handle_t *handle,
1737			      u32 bits_wanted,
1738			      u32 min_bits,
1739			      struct ocfs2_suballoc_result *res,
1740			      u16 *bits_left)
1741{
1742	int status;
1743	u16 chain;
1744	u64 next_group;
1745	struct inode *alloc_inode = ac->ac_inode;
1746	struct buffer_head *group_bh = NULL;
1747	struct buffer_head *prev_group_bh = NULL;
1748	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1749	struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1750	struct ocfs2_group_desc *bg;
1751
1752	chain = ac->ac_chain;
1753	trace_ocfs2_search_chain_begin(
1754		(unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
1755		bits_wanted, chain);
1756
1757	status = ocfs2_read_group_descriptor(alloc_inode, fe,
1758					     le64_to_cpu(cl->cl_recs[chain].c_blkno),
1759					     &group_bh);
1760	if (status < 0) {
1761		mlog_errno(status);
1762		goto bail;
1763	}
1764	bg = (struct ocfs2_group_desc *) group_bh->b_data;
1765
1766	status = -ENOSPC;
1767	/* for now, the chain search is a bit simplistic. We just use
1768	 * the 1st group with any empty bits. */
1769	while ((status = ac->ac_group_search(alloc_inode, group_bh,
1770					     bits_wanted, min_bits,
1771					     ac->ac_max_block,
1772					     res)) == -ENOSPC) {
1773		if (!bg->bg_next_group)
1774			break;
1775
1776		brelse(prev_group_bh);
1777		prev_group_bh = NULL;
1778
1779		next_group = le64_to_cpu(bg->bg_next_group);
1780		prev_group_bh = group_bh;
1781		group_bh = NULL;
1782		status = ocfs2_read_group_descriptor(alloc_inode, fe,
1783						     next_group, &group_bh);
1784		if (status < 0) {
1785			mlog_errno(status);
1786			goto bail;
1787		}
1788		bg = (struct ocfs2_group_desc *) group_bh->b_data;
1789	}
1790	if (status < 0) {
1791		if (status != -ENOSPC)
1792			mlog_errno(status);
1793		goto bail;
1794	}
1795
1796	trace_ocfs2_search_chain_succ(
1797		(unsigned long long)le64_to_cpu(bg->bg_blkno), res->sr_bits);
1798
1799	res->sr_bg_blkno = le64_to_cpu(bg->bg_blkno);
1800
1801	BUG_ON(res->sr_bits == 0);
1802	if (!status)
1803		ocfs2_bg_discontig_fix_result(ac, bg, res);
1804
1805	/*
1806	 * sr_bg_blkno might have been changed by
1807	 * ocfs2_bg_discontig_fix_result
1808	 */
1809	res->sr_bg_stable_blkno = group_bh->b_blocknr;
1810
1811	/*
1812	 * Keep track of previous block descriptor read. When
1813	 * we find a target, if we have read more than X
1814	 * number of descriptors, and the target is reasonably
1815	 * empty, relink him to top of his chain.
1816	 *
1817	 * We've read 0 extra blocks and only send one more to
1818	 * the transaction, yet the next guy to search has a
1819	 * much easier time.
1820	 *
1821	 * Do this *after* figuring out how many bits we're taking out
1822	 * of our target group.
1823	 */
1824	if (!ac->ac_disable_chain_relink &&
1825	    (prev_group_bh) &&
1826	    (ocfs2_block_group_reasonably_empty(bg, res->sr_bits))) {
1827		status = ocfs2_relink_block_group(handle, alloc_inode,
1828						  ac->ac_bh, group_bh,
1829						  prev_group_bh, chain);
1830		if (status < 0) {
1831			mlog_errno(status);
1832			goto bail;
1833		}
1834	}
1835
1836	if (ac->ac_find_loc_only)
1837		goto out_loc_only;
1838
1839	status = ocfs2_alloc_dinode_update_counts(alloc_inode, handle,
1840						  ac->ac_bh, res->sr_bits,
1841						  chain);
1842	if (status) {
1843		mlog_errno(status);
1844		goto bail;
1845	}
1846
1847	status = ocfs2_block_group_set_bits(handle,
1848					    alloc_inode,
1849					    bg,
1850					    group_bh,
1851					    res->sr_bit_offset,
1852					    res->sr_bits);
1853	if (status < 0) {
1854		ocfs2_rollback_alloc_dinode_counts(alloc_inode,
1855					ac->ac_bh, res->sr_bits, chain);
1856		mlog_errno(status);
1857		goto bail;
1858	}
1859
1860	trace_ocfs2_search_chain_end(
1861			(unsigned long long)le64_to_cpu(fe->i_blkno),
1862			res->sr_bits);
1863
1864out_loc_only:
1865	*bits_left = le16_to_cpu(bg->bg_free_bits_count);
1866bail:
1867	brelse(group_bh);
1868	brelse(prev_group_bh);
1869
1870	if (status)
1871		mlog_errno(status);
1872	return status;
1873}
1874
1875/* will give out up to bits_wanted contiguous bits. */
1876static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
1877				     handle_t *handle,
1878				     u32 bits_wanted,
1879				     u32 min_bits,
1880				     struct ocfs2_suballoc_result *res)
1881{
1882	int status;
1883	u16 victim, i;
1884	u16 bits_left = 0;
1885	u64 hint = ac->ac_last_group;
1886	struct ocfs2_chain_list *cl;
1887	struct ocfs2_dinode *fe;
1888
1889	BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1890	BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1891	BUG_ON(!ac->ac_bh);
1892
1893	fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1894
1895	/* The bh was validated by the inode read during
1896	 * ocfs2_reserve_suballoc_bits().  Any corruption is a code bug. */
1897	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
1898
1899	if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1900	    le32_to_cpu(fe->id1.bitmap1.i_total)) {
1901		status = ocfs2_error(ac->ac_inode->i_sb,
1902				     "Chain allocator dinode %llu has %u used bits but only %u total\n",
1903				     (unsigned long long)le64_to_cpu(fe->i_blkno),
1904				     le32_to_cpu(fe->id1.bitmap1.i_used),
1905				     le32_to_cpu(fe->id1.bitmap1.i_total));
1906		goto bail;
1907	}
1908
1909	res->sr_bg_blkno = hint;
1910	if (res->sr_bg_blkno) {
1911		/* Attempt to short-circuit the usual search mechanism
1912		 * by jumping straight to the most recently used
1913		 * allocation group. This helps us maintain some
1914		 * contiguousness across allocations. */
1915		status = ocfs2_search_one_group(ac, handle, bits_wanted,
1916						min_bits, res, &bits_left);
1917		if (!status)
1918			goto set_hint;
1919		if (status < 0 && status != -ENOSPC) {
1920			mlog_errno(status);
1921			goto bail;
1922		}
1923	}
1924
1925	cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1926
1927	victim = ocfs2_find_victim_chain(cl);
1928	ac->ac_chain = victim;
1929
1930	status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1931				    res, &bits_left);
1932	if (!status) {
1933		if (ocfs2_is_cluster_bitmap(ac->ac_inode))
1934			hint = res->sr_bg_blkno;
1935		else
1936			hint = ocfs2_group_from_res(res);
1937		goto set_hint;
1938	}
1939	if (status < 0 && status != -ENOSPC) {
1940		mlog_errno(status);
1941		goto bail;
1942	}
1943
1944	trace_ocfs2_claim_suballoc_bits(victim);
1945
1946	/* If we didn't pick a good victim, then just default to
1947	 * searching each chain in order. Don't allow chain relinking
1948	 * because we only calculate enough journal credits for one
1949	 * relink per alloc. */
1950	ac->ac_disable_chain_relink = 1;
1951	for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
1952		if (i == victim)
1953			continue;
1954		if (!cl->cl_recs[i].c_free)
1955			continue;
1956
1957		ac->ac_chain = i;
1958		status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1959					    res, &bits_left);
1960		if (!status) {
1961			hint = ocfs2_group_from_res(res);
1962			break;
1963		}
1964		if (status < 0 && status != -ENOSPC) {
1965			mlog_errno(status);
1966			goto bail;
1967		}
1968	}
1969
1970set_hint:
1971	if (status != -ENOSPC) {
1972		/* If the next search of this group is not likely to
1973		 * yield a suitable extent, then we reset the last
1974		 * group hint so as to not waste a disk read */
1975		if (bits_left < min_bits)
1976			ac->ac_last_group = 0;
1977		else
1978			ac->ac_last_group = hint;
1979	}
1980
1981bail:
1982	if (status)
1983		mlog_errno(status);
1984	return status;
1985}
1986
1987int ocfs2_claim_metadata(handle_t *handle,
1988			 struct ocfs2_alloc_context *ac,
1989			 u32 bits_wanted,
1990			 u64 *suballoc_loc,
1991			 u16 *suballoc_bit_start,
1992			 unsigned int *num_bits,
1993			 u64 *blkno_start)
1994{
1995	int status;
1996	struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
1997
1998	BUG_ON(!ac);
1999	BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
2000	BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
2001
2002	status = ocfs2_claim_suballoc_bits(ac,
2003					   handle,
2004					   bits_wanted,
2005					   1,
2006					   &res);
2007	if (status < 0) {
2008		mlog_errno(status);
2009		goto bail;
2010	}
2011	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2012
2013	*suballoc_loc = res.sr_bg_blkno;
2014	*suballoc_bit_start = res.sr_bit_offset;
2015	*blkno_start = res.sr_blkno;
2016	ac->ac_bits_given += res.sr_bits;
2017	*num_bits = res.sr_bits;
2018	status = 0;
2019bail:
2020	if (status)
2021		mlog_errno(status);
2022	return status;
2023}
2024
2025static void ocfs2_init_inode_ac_group(struct inode *dir,
2026				      struct buffer_head *parent_di_bh,
2027				      struct ocfs2_alloc_context *ac)
2028{
2029	struct ocfs2_dinode *di = (struct ocfs2_dinode *)parent_di_bh->b_data;
2030	/*
2031	 * Try to allocate inodes from some specific group.
2032	 *
2033	 * If the parent dir has recorded the last group used in allocation,
2034	 * cool, use it. Otherwise if we try to allocate new inode from the
2035	 * same slot the parent dir belongs to, use the same chunk.
2036	 *
2037	 * We are very careful here to avoid the mistake of setting
2038	 * ac_last_group to a group descriptor from a different (unlocked) slot.
2039	 */
2040	if (OCFS2_I(dir)->ip_last_used_group &&
2041	    OCFS2_I(dir)->ip_last_used_slot == ac->ac_alloc_slot)
2042		ac->ac_last_group = OCFS2_I(dir)->ip_last_used_group;
2043	else if (le16_to_cpu(di->i_suballoc_slot) == ac->ac_alloc_slot) {
2044		if (di->i_suballoc_loc)
2045			ac->ac_last_group = le64_to_cpu(di->i_suballoc_loc);
2046		else
2047			ac->ac_last_group = ocfs2_which_suballoc_group(
2048					le64_to_cpu(di->i_blkno),
2049					le16_to_cpu(di->i_suballoc_bit));
2050	}
2051}
2052
2053static inline void ocfs2_save_inode_ac_group(struct inode *dir,
2054					     struct ocfs2_alloc_context *ac)
2055{
2056	OCFS2_I(dir)->ip_last_used_group = ac->ac_last_group;
2057	OCFS2_I(dir)->ip_last_used_slot = ac->ac_alloc_slot;
2058}
2059
2060int ocfs2_find_new_inode_loc(struct inode *dir,
2061			     struct buffer_head *parent_fe_bh,
2062			     struct ocfs2_alloc_context *ac,
2063			     u64 *fe_blkno)
2064{
2065	int ret;
2066	handle_t *handle = NULL;
2067	struct ocfs2_suballoc_result *res;
2068
2069	BUG_ON(!ac);
2070	BUG_ON(ac->ac_bits_given != 0);
2071	BUG_ON(ac->ac_bits_wanted != 1);
2072	BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2073
2074	res = kzalloc(sizeof(*res), GFP_NOFS);
2075	if (res == NULL) {
2076		ret = -ENOMEM;
2077		mlog_errno(ret);
2078		goto out;
2079	}
2080
2081	ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2082
2083	/*
2084	 * The handle started here is for chain relink. Alternatively,
2085	 * we could just disable relink for these calls.
2086	 */
2087	handle = ocfs2_start_trans(OCFS2_SB(dir->i_sb), OCFS2_SUBALLOC_ALLOC);
2088	if (IS_ERR(handle)) {
2089		ret = PTR_ERR(handle);
2090		handle = NULL;
2091		mlog_errno(ret);
2092		goto out;
2093	}
2094
2095	/*
2096	 * This will instruct ocfs2_claim_suballoc_bits and
2097	 * ocfs2_search_one_group to search but save actual allocation
2098	 * for later.
2099	 */
2100	ac->ac_find_loc_only = 1;
2101
2102	ret = ocfs2_claim_suballoc_bits(ac, handle, 1, 1, res);
2103	if (ret < 0) {
2104		mlog_errno(ret);
2105		goto out;
2106	}
2107
2108	ac->ac_find_loc_priv = res;
2109	*fe_blkno = res->sr_blkno;
2110	ocfs2_update_inode_fsync_trans(handle, dir, 0);
2111out:
2112	if (handle)
2113		ocfs2_commit_trans(OCFS2_SB(dir->i_sb), handle);
2114
2115	if (ret)
2116		kfree(res);
2117
2118	return ret;
2119}
2120
2121int ocfs2_claim_new_inode_at_loc(handle_t *handle,
2122				 struct inode *dir,
2123				 struct ocfs2_alloc_context *ac,
2124				 u64 *suballoc_loc,
2125				 u16 *suballoc_bit,
2126				 u64 di_blkno)
2127{
2128	int ret;
2129	u16 chain;
2130	struct ocfs2_suballoc_result *res = ac->ac_find_loc_priv;
2131	struct buffer_head *bg_bh = NULL;
2132	struct ocfs2_group_desc *bg;
2133	struct ocfs2_dinode *di = (struct ocfs2_dinode *) ac->ac_bh->b_data;
2134
2135	/*
2136	 * Since di_blkno is being passed back in, we check for any
2137	 * inconsistencies which may have happened between
2138	 * calls. These are code bugs as di_blkno is not expected to
2139	 * change once returned from ocfs2_find_new_inode_loc()
2140	 */
2141	BUG_ON(res->sr_blkno != di_blkno);
2142
2143	ret = ocfs2_read_group_descriptor(ac->ac_inode, di,
2144					  res->sr_bg_stable_blkno, &bg_bh);
2145	if (ret) {
2146		mlog_errno(ret);
2147		goto out;
2148	}
2149
2150	bg = (struct ocfs2_group_desc *) bg_bh->b_data;
2151	chain = le16_to_cpu(bg->bg_chain);
2152
2153	ret = ocfs2_alloc_dinode_update_counts(ac->ac_inode, handle,
2154					       ac->ac_bh, res->sr_bits,
2155					       chain);
2156	if (ret) {
2157		mlog_errno(ret);
2158		goto out;
2159	}
2160
2161	ret = ocfs2_block_group_set_bits(handle,
2162					 ac->ac_inode,
2163					 bg,
2164					 bg_bh,
2165					 res->sr_bit_offset,
2166					 res->sr_bits);
2167	if (ret < 0) {
2168		ocfs2_rollback_alloc_dinode_counts(ac->ac_inode,
2169					       ac->ac_bh, res->sr_bits, chain);
2170		mlog_errno(ret);
2171		goto out;
2172	}
2173
2174	trace_ocfs2_claim_new_inode_at_loc((unsigned long long)di_blkno,
2175					   res->sr_bits);
2176
2177	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2178
2179	BUG_ON(res->sr_bits != 1);
2180
2181	*suballoc_loc = res->sr_bg_blkno;
2182	*suballoc_bit = res->sr_bit_offset;
2183	ac->ac_bits_given++;
2184	ocfs2_save_inode_ac_group(dir, ac);
2185
2186out:
2187	brelse(bg_bh);
2188
2189	return ret;
2190}
2191
2192int ocfs2_claim_new_inode(handle_t *handle,
2193			  struct inode *dir,
2194			  struct buffer_head *parent_fe_bh,
2195			  struct ocfs2_alloc_context *ac,
2196			  u64 *suballoc_loc,
2197			  u16 *suballoc_bit,
2198			  u64 *fe_blkno)
2199{
2200	int status;
2201	struct ocfs2_suballoc_result res;
2202
2203	BUG_ON(!ac);
2204	BUG_ON(ac->ac_bits_given != 0);
2205	BUG_ON(ac->ac_bits_wanted != 1);
2206	BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2207
2208	ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2209
2210	status = ocfs2_claim_suballoc_bits(ac,
2211					   handle,
2212					   1,
2213					   1,
2214					   &res);
2215	if (status < 0) {
2216		mlog_errno(status);
2217		goto bail;
2218	}
2219	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2220
2221	BUG_ON(res.sr_bits != 1);
2222
2223	*suballoc_loc = res.sr_bg_blkno;
2224	*suballoc_bit = res.sr_bit_offset;
2225	*fe_blkno = res.sr_blkno;
2226	ac->ac_bits_given++;
2227	ocfs2_save_inode_ac_group(dir, ac);
2228	status = 0;
2229bail:
2230	if (status)
2231		mlog_errno(status);
2232	return status;
2233}
2234
2235/* translate a group desc. blkno and it's bitmap offset into
2236 * disk cluster offset. */
2237static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
2238						   u64 bg_blkno,
2239						   u16 bg_bit_off)
2240{
2241	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2242	u32 cluster = 0;
2243
2244	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2245
2246	if (bg_blkno != osb->first_cluster_group_blkno)
2247		cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
2248	cluster += (u32) bg_bit_off;
2249	return cluster;
2250}
2251
2252/* given a cluster offset, calculate which block group it belongs to
2253 * and return that block offset. */
2254u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster)
2255{
2256	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2257	u32 group_no;
2258
2259	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2260
2261	group_no = cluster / osb->bitmap_cpg;
2262	if (!group_no)
2263		return osb->first_cluster_group_blkno;
2264	return ocfs2_clusters_to_blocks(inode->i_sb,
2265					group_no * osb->bitmap_cpg);
2266}
2267
2268/* given the block number of a cluster start, calculate which cluster
2269 * group and descriptor bitmap offset that corresponds to. */
2270static inline void ocfs2_block_to_cluster_group(struct inode *inode,
2271						u64 data_blkno,
2272						u64 *bg_blkno,
2273						u16 *bg_bit_off)
2274{
2275	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2276	u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
2277
2278	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2279
2280	*bg_blkno = ocfs2_which_cluster_group(inode,
2281					      data_cluster);
2282
2283	if (*bg_blkno == osb->first_cluster_group_blkno)
2284		*bg_bit_off = (u16) data_cluster;
2285	else
2286		*bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
2287							     data_blkno - *bg_blkno);
2288}
2289
2290/*
2291 * min_bits - minimum contiguous chunk from this total allocation we
2292 * can handle. set to what we asked for originally for a full
2293 * contig. allocation, set to '1' to indicate we can deal with extents
2294 * of any size.
2295 */
2296int __ocfs2_claim_clusters(handle_t *handle,
2297			   struct ocfs2_alloc_context *ac,
2298			   u32 min_clusters,
2299			   u32 max_clusters,
2300			   u32 *cluster_start,
2301			   u32 *num_clusters)
2302{
2303	int status;
2304	unsigned int bits_wanted = max_clusters;
2305	struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
2306	struct ocfs2_super *osb = OCFS2_SB(ac->ac_inode->i_sb);
2307
2308	BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
2309
2310	BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
2311	       && ac->ac_which != OCFS2_AC_USE_MAIN);
2312
2313	if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
2314		WARN_ON(min_clusters > 1);
2315
2316		status = ocfs2_claim_local_alloc_bits(osb,
2317						      handle,
2318						      ac,
2319						      bits_wanted,
2320						      cluster_start,
2321						      num_clusters);
2322		if (!status)
2323			atomic_inc(&osb->alloc_stats.local_data);
2324	} else {
2325		if (min_clusters > (osb->bitmap_cpg - 1)) {
2326			/* The only paths asking for contiguousness
2327			 * should know about this already. */
2328			mlog(ML_ERROR, "minimum allocation requested %u exceeds "
2329			     "group bitmap size %u!\n", min_clusters,
2330			     osb->bitmap_cpg);
2331			status = -ENOSPC;
2332			goto bail;
2333		}
2334		/* clamp the current request down to a realistic size. */
2335		if (bits_wanted > (osb->bitmap_cpg - 1))
2336			bits_wanted = osb->bitmap_cpg - 1;
2337
2338		status = ocfs2_claim_suballoc_bits(ac,
2339						   handle,
2340						   bits_wanted,
2341						   min_clusters,
2342						   &res);
2343		if (!status) {
2344			BUG_ON(res.sr_blkno); /* cluster alloc can't set */
2345			*cluster_start =
2346				ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
2347								 res.sr_bg_blkno,
2348								 res.sr_bit_offset);
2349			atomic_inc(&osb->alloc_stats.bitmap_data);
2350			*num_clusters = res.sr_bits;
2351		}
2352	}
2353	if (status < 0) {
2354		if (status != -ENOSPC)
2355			mlog_errno(status);
2356		goto bail;
2357	}
2358
2359	ac->ac_bits_given += *num_clusters;
2360
2361bail:
2362	if (status)
2363		mlog_errno(status);
2364	return status;
2365}
2366
2367int ocfs2_claim_clusters(handle_t *handle,
2368			 struct ocfs2_alloc_context *ac,
2369			 u32 min_clusters,
2370			 u32 *cluster_start,
2371			 u32 *num_clusters)
2372{
2373	unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
2374
2375	return __ocfs2_claim_clusters(handle, ac, min_clusters,
2376				      bits_wanted, cluster_start, num_clusters);
2377}
2378
2379static int ocfs2_block_group_clear_bits(handle_t *handle,
2380					struct inode *alloc_inode,
2381					struct ocfs2_group_desc *bg,
2382					struct buffer_head *group_bh,
2383					unsigned int bit_off,
2384					unsigned int num_bits,
2385					void (*undo_fn)(unsigned int bit,
2386							unsigned long *bmap))
2387{
2388	int status;
2389	unsigned int tmp;
2390	struct ocfs2_group_desc *undo_bg = NULL;
2391	struct journal_head *jh;
2392
2393	/* The caller got this descriptor from
2394	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
2395	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
2396
2397	trace_ocfs2_block_group_clear_bits(bit_off, num_bits);
2398
2399	BUG_ON(undo_fn && !ocfs2_is_cluster_bitmap(alloc_inode));
2400	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
2401					 group_bh,
2402					 undo_fn ?
2403					 OCFS2_JOURNAL_ACCESS_UNDO :
2404					 OCFS2_JOURNAL_ACCESS_WRITE);
2405	if (status < 0) {
2406		mlog_errno(status);
2407		goto bail;
2408	}
2409
2410	jh = bh2jh(group_bh);
2411	if (undo_fn) {
2412		spin_lock(&jh->b_state_lock);
2413		undo_bg = (struct ocfs2_group_desc *) jh->b_committed_data;
 
2414		BUG_ON(!undo_bg);
2415	}
2416
2417	tmp = num_bits;
2418	while(tmp--) {
2419		ocfs2_clear_bit((bit_off + tmp),
2420				(unsigned long *) bg->bg_bitmap);
2421		if (undo_fn)
2422			undo_fn(bit_off + tmp,
2423				(unsigned long *) undo_bg->bg_bitmap);
2424	}
2425	le16_add_cpu(&bg->bg_free_bits_count, num_bits);
2426	if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
2427		if (undo_fn)
2428			spin_unlock(&jh->b_state_lock);
2429		return ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit count %u but claims %u are freed. num_bits %d\n",
2430				   (unsigned long long)le64_to_cpu(bg->bg_blkno),
2431				   le16_to_cpu(bg->bg_bits),
2432				   le16_to_cpu(bg->bg_free_bits_count),
2433				   num_bits);
2434	}
2435
2436	if (undo_fn)
2437		spin_unlock(&jh->b_state_lock);
2438
2439	ocfs2_journal_dirty(handle, group_bh);
2440bail:
2441	return status;
2442}
2443
2444/*
2445 * expects the suballoc inode to already be locked.
2446 */
2447static int _ocfs2_free_suballoc_bits(handle_t *handle,
2448				     struct inode *alloc_inode,
2449				     struct buffer_head *alloc_bh,
2450				     unsigned int start_bit,
2451				     u64 bg_blkno,
2452				     unsigned int count,
2453				     void (*undo_fn)(unsigned int bit,
2454						     unsigned long *bitmap))
2455{
2456	int status = 0;
2457	u32 tmp_used;
2458	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
2459	struct ocfs2_chain_list *cl = &fe->id2.i_chain;
2460	struct buffer_head *group_bh = NULL;
2461	struct ocfs2_group_desc *group;
2462
2463	/* The alloc_bh comes from ocfs2_free_dinode() or
2464	 * ocfs2_free_clusters().  The callers have all locked the
2465	 * allocator and gotten alloc_bh from the lock call.  This
2466	 * validates the dinode buffer.  Any corruption that has happened
2467	 * is a code bug. */
2468	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
2469	BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
2470
2471	trace_ocfs2_free_suballoc_bits(
2472		(unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
2473		(unsigned long long)bg_blkno,
2474		start_bit, count);
2475
2476	status = ocfs2_read_group_descriptor(alloc_inode, fe, bg_blkno,
2477					     &group_bh);
2478	if (status < 0) {
2479		mlog_errno(status);
2480		goto bail;
2481	}
2482	group = (struct ocfs2_group_desc *) group_bh->b_data;
2483
2484	BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
2485
2486	status = ocfs2_block_group_clear_bits(handle, alloc_inode,
2487					      group, group_bh,
2488					      start_bit, count, undo_fn);
2489	if (status < 0) {
2490		mlog_errno(status);
2491		goto bail;
2492	}
2493
2494	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
2495					 alloc_bh, OCFS2_JOURNAL_ACCESS_WRITE);
2496	if (status < 0) {
2497		mlog_errno(status);
2498		ocfs2_block_group_set_bits(handle, alloc_inode, group, group_bh,
2499				start_bit, count);
2500		goto bail;
2501	}
2502
2503	le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
2504		     count);
2505	tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
2506	fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
2507	ocfs2_journal_dirty(handle, alloc_bh);
2508
2509bail:
2510	brelse(group_bh);
 
 
 
2511	return status;
2512}
2513
2514int ocfs2_free_suballoc_bits(handle_t *handle,
2515			     struct inode *alloc_inode,
2516			     struct buffer_head *alloc_bh,
2517			     unsigned int start_bit,
2518			     u64 bg_blkno,
2519			     unsigned int count)
2520{
2521	return _ocfs2_free_suballoc_bits(handle, alloc_inode, alloc_bh,
2522					 start_bit, bg_blkno, count, NULL);
2523}
2524
2525int ocfs2_free_dinode(handle_t *handle,
2526		      struct inode *inode_alloc_inode,
2527		      struct buffer_head *inode_alloc_bh,
2528		      struct ocfs2_dinode *di)
2529{
2530	u64 blk = le64_to_cpu(di->i_blkno);
2531	u16 bit = le16_to_cpu(di->i_suballoc_bit);
2532	u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
2533
2534	if (di->i_suballoc_loc)
2535		bg_blkno = le64_to_cpu(di->i_suballoc_loc);
2536	return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
2537					inode_alloc_bh, bit, bg_blkno, 1);
2538}
2539
2540static int _ocfs2_free_clusters(handle_t *handle,
2541				struct inode *bitmap_inode,
2542				struct buffer_head *bitmap_bh,
2543				u64 start_blk,
2544				unsigned int num_clusters,
2545				void (*undo_fn)(unsigned int bit,
2546						unsigned long *bitmap))
2547{
2548	int status;
2549	u16 bg_start_bit;
2550	u64 bg_blkno;
2551
2552	/* You can't ever have a contiguous set of clusters
2553	 * bigger than a block group bitmap so we never have to worry
2554	 * about looping on them.
2555	 * This is expensive. We can safely remove once this stuff has
2556	 * gotten tested really well. */
2557	BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb,
2558				ocfs2_blocks_to_clusters(bitmap_inode->i_sb,
2559							 start_blk)));
2560
2561
2562	ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
2563				     &bg_start_bit);
2564
2565	trace_ocfs2_free_clusters((unsigned long long)bg_blkno,
2566			(unsigned long long)start_blk,
2567			bg_start_bit, num_clusters);
2568
2569	status = _ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
2570					   bg_start_bit, bg_blkno,
2571					   num_clusters, undo_fn);
2572	if (status < 0) {
2573		mlog_errno(status);
2574		goto out;
2575	}
2576
2577	ocfs2_local_alloc_seen_free_bits(OCFS2_SB(bitmap_inode->i_sb),
2578					 num_clusters);
2579
2580out:
 
 
2581	return status;
2582}
2583
2584int ocfs2_free_clusters(handle_t *handle,
2585			struct inode *bitmap_inode,
2586			struct buffer_head *bitmap_bh,
2587			u64 start_blk,
2588			unsigned int num_clusters)
2589{
2590	return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2591				    start_blk, num_clusters,
2592				    _ocfs2_set_bit);
2593}
2594
2595/*
2596 * Give never-used clusters back to the global bitmap.  We don't need
2597 * to protect these bits in the undo buffer.
2598 */
2599int ocfs2_release_clusters(handle_t *handle,
2600			   struct inode *bitmap_inode,
2601			   struct buffer_head *bitmap_bh,
2602			   u64 start_blk,
2603			   unsigned int num_clusters)
2604{
2605	return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2606				    start_blk, num_clusters,
2607				    _ocfs2_clear_bit);
2608}
2609
2610/*
2611 * For a given allocation, determine which allocators will need to be
2612 * accessed, and lock them, reserving the appropriate number of bits.
2613 *
2614 * Sparse file systems call this from ocfs2_write_begin_nolock()
2615 * and ocfs2_allocate_unwritten_extents().
2616 *
2617 * File systems which don't support holes call this from
2618 * ocfs2_extend_allocation().
2619 */
2620int ocfs2_lock_allocators(struct inode *inode,
2621			  struct ocfs2_extent_tree *et,
2622			  u32 clusters_to_add, u32 extents_to_split,
2623			  struct ocfs2_alloc_context **data_ac,
2624			  struct ocfs2_alloc_context **meta_ac)
2625{
2626	int ret = 0, num_free_extents;
2627	unsigned int max_recs_needed = clusters_to_add + 2 * extents_to_split;
2628	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2629
2630	*meta_ac = NULL;
2631	if (data_ac)
2632		*data_ac = NULL;
2633
2634	BUG_ON(clusters_to_add != 0 && data_ac == NULL);
2635
2636	num_free_extents = ocfs2_num_free_extents(et);
2637	if (num_free_extents < 0) {
2638		ret = num_free_extents;
2639		mlog_errno(ret);
2640		goto out;
2641	}
2642
2643	/*
2644	 * Sparse allocation file systems need to be more conservative
2645	 * with reserving room for expansion - the actual allocation
2646	 * happens while we've got a journal handle open so re-taking
2647	 * a cluster lock (because we ran out of room for another
2648	 * extent) will violate ordering rules.
2649	 *
2650	 * Most of the time we'll only be seeing this 1 cluster at a time
2651	 * anyway.
2652	 *
2653	 * Always lock for any unwritten extents - we might want to
2654	 * add blocks during a split.
2655	 */
2656	if (!num_free_extents ||
2657	    (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed)) {
2658		ret = ocfs2_reserve_new_metadata(osb, et->et_root_el, meta_ac);
2659		if (ret < 0) {
2660			if (ret != -ENOSPC)
2661				mlog_errno(ret);
2662			goto out;
2663		}
2664	}
2665
2666	if (clusters_to_add == 0)
2667		goto out;
2668
2669	ret = ocfs2_reserve_clusters(osb, clusters_to_add, data_ac);
2670	if (ret < 0) {
2671		if (ret != -ENOSPC)
2672			mlog_errno(ret);
2673		goto out;
2674	}
2675
2676out:
2677	if (ret) {
2678		if (*meta_ac) {
2679			ocfs2_free_alloc_context(*meta_ac);
2680			*meta_ac = NULL;
2681		}
2682
2683		/*
2684		 * We cannot have an error and a non null *data_ac.
2685		 */
2686	}
2687
2688	return ret;
2689}
2690
2691/*
2692 * Read the inode specified by blkno to get suballoc_slot and
2693 * suballoc_bit.
2694 */
2695static int ocfs2_get_suballoc_slot_bit(struct ocfs2_super *osb, u64 blkno,
2696				       u16 *suballoc_slot, u64 *group_blkno,
2697				       u16 *suballoc_bit)
2698{
2699	int status;
2700	struct buffer_head *inode_bh = NULL;
2701	struct ocfs2_dinode *inode_fe;
2702
2703	trace_ocfs2_get_suballoc_slot_bit((unsigned long long)blkno);
2704
2705	/* dirty read disk */
2706	status = ocfs2_read_blocks_sync(osb, blkno, 1, &inode_bh);
2707	if (status < 0) {
2708		mlog(ML_ERROR, "read block %llu failed %d\n",
2709		     (unsigned long long)blkno, status);
2710		goto bail;
2711	}
2712
2713	inode_fe = (struct ocfs2_dinode *) inode_bh->b_data;
2714	if (!OCFS2_IS_VALID_DINODE(inode_fe)) {
2715		mlog(ML_ERROR, "invalid inode %llu requested\n",
2716		     (unsigned long long)blkno);
2717		status = -EINVAL;
2718		goto bail;
2719	}
2720
2721	if (le16_to_cpu(inode_fe->i_suballoc_slot) != (u16)OCFS2_INVALID_SLOT &&
2722	    (u32)le16_to_cpu(inode_fe->i_suballoc_slot) > osb->max_slots - 1) {
2723		mlog(ML_ERROR, "inode %llu has invalid suballoc slot %u\n",
2724		     (unsigned long long)blkno,
2725		     (u32)le16_to_cpu(inode_fe->i_suballoc_slot));
2726		status = -EINVAL;
2727		goto bail;
2728	}
2729
2730	if (suballoc_slot)
2731		*suballoc_slot = le16_to_cpu(inode_fe->i_suballoc_slot);
2732	if (suballoc_bit)
2733		*suballoc_bit = le16_to_cpu(inode_fe->i_suballoc_bit);
2734	if (group_blkno)
2735		*group_blkno = le64_to_cpu(inode_fe->i_suballoc_loc);
2736
2737bail:
2738	brelse(inode_bh);
2739
2740	if (status)
2741		mlog_errno(status);
2742	return status;
2743}
2744
2745/*
2746 * test whether bit is SET in allocator bitmap or not.  on success, 0
2747 * is returned and *res is 1 for SET; 0 otherwise.  when fails, errno
2748 * is returned and *res is meaningless.  Call this after you have
2749 * cluster locked against suballoc, or you may get a result based on
2750 * non-up2date contents
2751 */
2752static int ocfs2_test_suballoc_bit(struct ocfs2_super *osb,
2753				   struct inode *suballoc,
2754				   struct buffer_head *alloc_bh,
2755				   u64 group_blkno, u64 blkno,
2756				   u16 bit, int *res)
2757{
2758	struct ocfs2_dinode *alloc_di;
2759	struct ocfs2_group_desc *group;
2760	struct buffer_head *group_bh = NULL;
2761	u64 bg_blkno;
2762	int status;
2763
2764	trace_ocfs2_test_suballoc_bit((unsigned long long)blkno,
2765				      (unsigned int)bit);
2766
2767	alloc_di = (struct ocfs2_dinode *)alloc_bh->b_data;
2768	if ((bit + 1) > ocfs2_bits_per_group(&alloc_di->id2.i_chain)) {
2769		mlog(ML_ERROR, "suballoc bit %u out of range of %u\n",
2770		     (unsigned int)bit,
2771		     ocfs2_bits_per_group(&alloc_di->id2.i_chain));
2772		status = -EINVAL;
2773		goto bail;
2774	}
2775
2776	bg_blkno = group_blkno ? group_blkno :
2777		   ocfs2_which_suballoc_group(blkno, bit);
2778	status = ocfs2_read_group_descriptor(suballoc, alloc_di, bg_blkno,
2779					     &group_bh);
2780	if (status < 0) {
2781		mlog(ML_ERROR, "read group %llu failed %d\n",
2782		     (unsigned long long)bg_blkno, status);
2783		goto bail;
2784	}
2785
2786	group = (struct ocfs2_group_desc *) group_bh->b_data;
2787	*res = ocfs2_test_bit(bit, (unsigned long *)group->bg_bitmap);
2788
2789bail:
2790	brelse(group_bh);
2791
2792	if (status)
2793		mlog_errno(status);
2794	return status;
2795}
2796
2797/*
2798 * Test if the bit representing this inode (blkno) is set in the
2799 * suballocator.
2800 *
2801 * On success, 0 is returned and *res is 1 for SET; 0 otherwise.
2802 *
2803 * In the event of failure, a negative value is returned and *res is
2804 * meaningless.
2805 *
2806 * Callers must make sure to hold nfs_sync_lock to prevent
2807 * ocfs2_delete_inode() on another node from accessing the same
2808 * suballocator concurrently.
2809 */
2810int ocfs2_test_inode_bit(struct ocfs2_super *osb, u64 blkno, int *res)
2811{
2812	int status;
2813	u64 group_blkno = 0;
2814	u16 suballoc_bit = 0, suballoc_slot = 0;
2815	struct inode *inode_alloc_inode;
2816	struct buffer_head *alloc_bh = NULL;
2817
2818	trace_ocfs2_test_inode_bit((unsigned long long)blkno);
2819
2820	status = ocfs2_get_suballoc_slot_bit(osb, blkno, &suballoc_slot,
2821					     &group_blkno, &suballoc_bit);
2822	if (status < 0) {
2823		mlog(ML_ERROR, "get alloc slot and bit failed %d\n", status);
2824		goto bail;
2825	}
2826
2827	if (suballoc_slot == (u16)OCFS2_INVALID_SLOT)
2828		inode_alloc_inode = ocfs2_get_system_file_inode(osb,
2829			GLOBAL_INODE_ALLOC_SYSTEM_INODE, suballoc_slot);
2830	else
2831		inode_alloc_inode = ocfs2_get_system_file_inode(osb,
2832			INODE_ALLOC_SYSTEM_INODE, suballoc_slot);
2833	if (!inode_alloc_inode) {
2834		/* the error code could be inaccurate, but we are not able to
2835		 * get the correct one. */
2836		status = -EINVAL;
2837		mlog(ML_ERROR, "unable to get alloc inode in slot %u\n",
2838		     (u32)suballoc_slot);
2839		goto bail;
2840	}
2841
2842	inode_lock(inode_alloc_inode);
2843	status = ocfs2_inode_lock(inode_alloc_inode, &alloc_bh, 0);
2844	if (status < 0) {
2845		inode_unlock(inode_alloc_inode);
2846		iput(inode_alloc_inode);
2847		mlog(ML_ERROR, "lock on alloc inode on slot %u failed %d\n",
2848		     (u32)suballoc_slot, status);
2849		goto bail;
2850	}
2851
2852	status = ocfs2_test_suballoc_bit(osb, inode_alloc_inode, alloc_bh,
2853					 group_blkno, blkno, suballoc_bit, res);
2854	if (status < 0)
2855		mlog(ML_ERROR, "test suballoc bit failed %d\n", status);
2856
2857	ocfs2_inode_unlock(inode_alloc_inode, 0);
2858	inode_unlock(inode_alloc_inode);
2859
2860	iput(inode_alloc_inode);
2861	brelse(alloc_bh);
2862bail:
2863	if (status)
2864		mlog_errno(status);
2865	return status;
2866}