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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}
v3.15
 
   1/* -*- mode: c; c-basic-offset: 8; -*-
   2 * vim: noexpandtab sw=8 ts=8 sts=0:
   3 *
   4 * suballoc.c
   5 *
   6 * metadata alloc and free
   7 * Inspired by ext3 block groups.
   8 *
   9 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
  10 *
  11 * This program is free software; you can redistribute it and/or
  12 * modify it under the terms of the GNU General Public
  13 * License as published by the Free Software Foundation; either
  14 * version 2 of the License, or (at your option) any later version.
  15 *
  16 * This program is distributed in the hope that it will be useful,
  17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19 * General Public License for more details.
  20 *
  21 * You should have received a copy of the GNU General Public
  22 * License along with this program; if not, write to the
  23 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  24 * Boston, MA 021110-1307, USA.
  25 */
  26
  27#include <linux/fs.h>
  28#include <linux/types.h>
  29#include <linux/slab.h>
  30#include <linux/highmem.h>
  31
  32#include <cluster/masklog.h>
  33
  34#include "ocfs2.h"
  35
  36#include "alloc.h"
  37#include "blockcheck.h"
  38#include "dlmglue.h"
  39#include "inode.h"
  40#include "journal.h"
  41#include "localalloc.h"
  42#include "suballoc.h"
  43#include "super.h"
  44#include "sysfile.h"
  45#include "uptodate.h"
  46#include "ocfs2_trace.h"
  47
  48#include "buffer_head_io.h"
  49
  50#define NOT_ALLOC_NEW_GROUP		0
  51#define ALLOC_NEW_GROUP			0x1
  52#define ALLOC_GROUPS_FROM_GLOBAL	0x2
  53
  54#define OCFS2_MAX_TO_STEAL		1024
  55
  56struct ocfs2_suballoc_result {
  57	u64		sr_bg_blkno;	/* The bg we allocated from.  Set
  58					   to 0 when a block group is
  59					   contiguous. */
  60	u64		sr_bg_stable_blkno; /*
  61					     * Doesn't change, always
  62					     * set to target block
  63					     * group descriptor
  64					     * block.
  65					     */
  66	u64		sr_blkno;	/* The first allocated block */
  67	unsigned int	sr_bit_offset;	/* The bit in the bg */
  68	unsigned int	sr_bits;	/* How many bits we claimed */
  69};
  70
  71static u64 ocfs2_group_from_res(struct ocfs2_suballoc_result *res)
  72{
  73	if (res->sr_blkno == 0)
  74		return 0;
  75
  76	if (res->sr_bg_blkno)
  77		return res->sr_bg_blkno;
  78
  79	return ocfs2_which_suballoc_group(res->sr_blkno, res->sr_bit_offset);
  80}
  81
  82static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg);
  83static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe);
  84static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl);
  85static int ocfs2_block_group_fill(handle_t *handle,
  86				  struct inode *alloc_inode,
  87				  struct buffer_head *bg_bh,
  88				  u64 group_blkno,
  89				  unsigned int group_clusters,
  90				  u16 my_chain,
  91				  struct ocfs2_chain_list *cl);
  92static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
  93				   struct inode *alloc_inode,
  94				   struct buffer_head *bh,
  95				   u64 max_block,
  96				   u64 *last_alloc_group,
  97				   int flags);
  98
  99static int ocfs2_cluster_group_search(struct inode *inode,
 100				      struct buffer_head *group_bh,
 101				      u32 bits_wanted, u32 min_bits,
 102				      u64 max_block,
 103				      struct ocfs2_suballoc_result *res);
 104static int ocfs2_block_group_search(struct inode *inode,
 105				    struct buffer_head *group_bh,
 106				    u32 bits_wanted, u32 min_bits,
 107				    u64 max_block,
 108				    struct ocfs2_suballoc_result *res);
 109static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
 110				     handle_t *handle,
 111				     u32 bits_wanted,
 112				     u32 min_bits,
 113				     struct ocfs2_suballoc_result *res);
 114static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
 115					 int nr);
 116static int ocfs2_relink_block_group(handle_t *handle,
 117				    struct inode *alloc_inode,
 118				    struct buffer_head *fe_bh,
 119				    struct buffer_head *bg_bh,
 120				    struct buffer_head *prev_bg_bh,
 121				    u16 chain);
 122static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
 123						     u32 wanted);
 124static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
 125						   u64 bg_blkno,
 126						   u16 bg_bit_off);
 127static inline void ocfs2_block_to_cluster_group(struct inode *inode,
 128						u64 data_blkno,
 129						u64 *bg_blkno,
 130						u16 *bg_bit_off);
 131static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
 132					     u32 bits_wanted, u64 max_block,
 133					     int flags,
 134					     struct ocfs2_alloc_context **ac);
 135
 136void ocfs2_free_ac_resource(struct ocfs2_alloc_context *ac)
 137{
 138	struct inode *inode = ac->ac_inode;
 139
 140	if (inode) {
 141		if (ac->ac_which != OCFS2_AC_USE_LOCAL)
 142			ocfs2_inode_unlock(inode, 1);
 143
 144		mutex_unlock(&inode->i_mutex);
 145
 146		iput(inode);
 147		ac->ac_inode = NULL;
 148	}
 149	brelse(ac->ac_bh);
 150	ac->ac_bh = NULL;
 151	ac->ac_resv = NULL;
 152	if (ac->ac_find_loc_priv) {
 153		kfree(ac->ac_find_loc_priv);
 154		ac->ac_find_loc_priv = NULL;
 155	}
 156}
 157
 158void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
 159{
 160	ocfs2_free_ac_resource(ac);
 161	kfree(ac);
 162}
 163
 164static u32 ocfs2_bits_per_group(struct ocfs2_chain_list *cl)
 165{
 166	return (u32)le16_to_cpu(cl->cl_cpg) * (u32)le16_to_cpu(cl->cl_bpc);
 167}
 168
 169#define do_error(fmt, ...)						\
 170	do{								\
 171		if (resize)					\
 172			mlog(ML_ERROR, fmt "\n", ##__VA_ARGS__);	\
 173		else							\
 174			ocfs2_error(sb, fmt, ##__VA_ARGS__);		\
 175	} while (0)
 176
 177static int ocfs2_validate_gd_self(struct super_block *sb,
 178				  struct buffer_head *bh,
 179				  int resize)
 180{
 181	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 182
 183	if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
 184		do_error("Group descriptor #%llu has bad signature %.*s",
 185			 (unsigned long long)bh->b_blocknr, 7,
 186			 gd->bg_signature);
 187		return -EINVAL;
 188	}
 189
 190	if (le64_to_cpu(gd->bg_blkno) != bh->b_blocknr) {
 191		do_error("Group descriptor #%llu has an invalid bg_blkno "
 192			 "of %llu",
 193			 (unsigned long long)bh->b_blocknr,
 194			 (unsigned long long)le64_to_cpu(gd->bg_blkno));
 195		return -EINVAL;
 196	}
 197
 198	if (le32_to_cpu(gd->bg_generation) != OCFS2_SB(sb)->fs_generation) {
 199		do_error("Group descriptor #%llu has an invalid "
 200			 "fs_generation of #%u",
 201			 (unsigned long long)bh->b_blocknr,
 202			 le32_to_cpu(gd->bg_generation));
 203		return -EINVAL;
 204	}
 205
 206	if (le16_to_cpu(gd->bg_free_bits_count) > le16_to_cpu(gd->bg_bits)) {
 207		do_error("Group descriptor #%llu has bit count %u but "
 208			 "claims that %u are free",
 209			 (unsigned long long)bh->b_blocknr,
 210			 le16_to_cpu(gd->bg_bits),
 211			 le16_to_cpu(gd->bg_free_bits_count));
 212		return -EINVAL;
 213	}
 214
 215	if (le16_to_cpu(gd->bg_bits) > (8 * le16_to_cpu(gd->bg_size))) {
 216		do_error("Group descriptor #%llu has bit count %u but "
 217			 "max bitmap bits of %u",
 218			 (unsigned long long)bh->b_blocknr,
 219			 le16_to_cpu(gd->bg_bits),
 220			 8 * le16_to_cpu(gd->bg_size));
 221		return -EINVAL;
 222	}
 223
 224	return 0;
 225}
 226
 227static int ocfs2_validate_gd_parent(struct super_block *sb,
 228				    struct ocfs2_dinode *di,
 229				    struct buffer_head *bh,
 230				    int resize)
 231{
 232	unsigned int max_bits;
 233	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 234
 235	if (di->i_blkno != gd->bg_parent_dinode) {
 236		do_error("Group descriptor #%llu has bad parent "
 237			 "pointer (%llu, expected %llu)",
 238			 (unsigned long long)bh->b_blocknr,
 239			 (unsigned long long)le64_to_cpu(gd->bg_parent_dinode),
 240			 (unsigned long long)le64_to_cpu(di->i_blkno));
 241		return -EINVAL;
 242	}
 243
 244	max_bits = le16_to_cpu(di->id2.i_chain.cl_cpg) * le16_to_cpu(di->id2.i_chain.cl_bpc);
 245	if (le16_to_cpu(gd->bg_bits) > max_bits) {
 246		do_error("Group descriptor #%llu has bit count of %u",
 247			 (unsigned long long)bh->b_blocknr,
 248			 le16_to_cpu(gd->bg_bits));
 249		return -EINVAL;
 250	}
 251
 252	/* In resize, we may meet the case bg_chain == cl_next_free_rec. */
 253	if ((le16_to_cpu(gd->bg_chain) >
 254	     le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) ||
 255	    ((le16_to_cpu(gd->bg_chain) ==
 256	     le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) && !resize)) {
 257		do_error("Group descriptor #%llu has bad chain %u",
 258			 (unsigned long long)bh->b_blocknr,
 259			 le16_to_cpu(gd->bg_chain));
 260		return -EINVAL;
 261	}
 262
 263	return 0;
 264}
 265
 266#undef do_error
 267
 268/*
 269 * This version only prints errors.  It does not fail the filesystem, and
 270 * exists only for resize.
 271 */
 272int ocfs2_check_group_descriptor(struct super_block *sb,
 273				 struct ocfs2_dinode *di,
 274				 struct buffer_head *bh)
 275{
 276	int rc;
 277	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 278
 279	BUG_ON(!buffer_uptodate(bh));
 280
 281	/*
 282	 * If the ecc fails, we return the error but otherwise
 283	 * leave the filesystem running.  We know any error is
 284	 * local to this block.
 285	 */
 286	rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
 287	if (rc) {
 288		mlog(ML_ERROR,
 289		     "Checksum failed for group descriptor %llu\n",
 290		     (unsigned long long)bh->b_blocknr);
 291	} else
 292		rc = ocfs2_validate_gd_self(sb, bh, 1);
 293	if (!rc)
 294		rc = ocfs2_validate_gd_parent(sb, di, bh, 1);
 295
 296	return rc;
 297}
 298
 299static int ocfs2_validate_group_descriptor(struct super_block *sb,
 300					   struct buffer_head *bh)
 301{
 302	int rc;
 303	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 304
 305	trace_ocfs2_validate_group_descriptor(
 306					(unsigned long long)bh->b_blocknr);
 307
 308	BUG_ON(!buffer_uptodate(bh));
 309
 310	/*
 311	 * If the ecc fails, we return the error but otherwise
 312	 * leave the filesystem running.  We know any error is
 313	 * local to this block.
 314	 */
 315	rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
 316	if (rc)
 317		return rc;
 318
 319	/*
 320	 * Errors after here are fatal.
 321	 */
 322
 323	return ocfs2_validate_gd_self(sb, bh, 0);
 324}
 325
 326int ocfs2_read_group_descriptor(struct inode *inode, struct ocfs2_dinode *di,
 327				u64 gd_blkno, struct buffer_head **bh)
 328{
 329	int rc;
 330	struct buffer_head *tmp = *bh;
 331
 332	rc = ocfs2_read_block(INODE_CACHE(inode), gd_blkno, &tmp,
 333			      ocfs2_validate_group_descriptor);
 334	if (rc)
 335		goto out;
 336
 337	rc = ocfs2_validate_gd_parent(inode->i_sb, di, tmp, 0);
 338	if (rc) {
 339		brelse(tmp);
 340		goto out;
 341	}
 342
 343	/* If ocfs2_read_block() got us a new bh, pass it up. */
 344	if (!*bh)
 345		*bh = tmp;
 346
 347out:
 348	return rc;
 349}
 350
 351static void ocfs2_bg_discontig_add_extent(struct ocfs2_super *osb,
 352					  struct ocfs2_group_desc *bg,
 353					  struct ocfs2_chain_list *cl,
 354					  u64 p_blkno, unsigned int clusters)
 355{
 356	struct ocfs2_extent_list *el = &bg->bg_list;
 357	struct ocfs2_extent_rec *rec;
 358
 359	BUG_ON(!ocfs2_supports_discontig_bg(osb));
 360	if (!el->l_next_free_rec)
 361		el->l_count = cpu_to_le16(ocfs2_extent_recs_per_gd(osb->sb));
 362	rec = &el->l_recs[le16_to_cpu(el->l_next_free_rec)];
 363	rec->e_blkno = cpu_to_le64(p_blkno);
 364	rec->e_cpos = cpu_to_le32(le16_to_cpu(bg->bg_bits) /
 365				  le16_to_cpu(cl->cl_bpc));
 366	rec->e_leaf_clusters = cpu_to_le16(clusters);
 367	le16_add_cpu(&bg->bg_bits, clusters * le16_to_cpu(cl->cl_bpc));
 368	le16_add_cpu(&bg->bg_free_bits_count,
 369		     clusters * le16_to_cpu(cl->cl_bpc));
 370	le16_add_cpu(&el->l_next_free_rec, 1);
 371}
 372
 373static int ocfs2_block_group_fill(handle_t *handle,
 374				  struct inode *alloc_inode,
 375				  struct buffer_head *bg_bh,
 376				  u64 group_blkno,
 377				  unsigned int group_clusters,
 378				  u16 my_chain,
 379				  struct ocfs2_chain_list *cl)
 380{
 381	int status = 0;
 382	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 383	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 384	struct super_block * sb = alloc_inode->i_sb;
 385
 386	if (((unsigned long long) bg_bh->b_blocknr) != group_blkno) {
 387		ocfs2_error(alloc_inode->i_sb, "group block (%llu) != "
 388			    "b_blocknr (%llu)",
 389			    (unsigned long long)group_blkno,
 390			    (unsigned long long) bg_bh->b_blocknr);
 391		status = -EIO;
 392		goto bail;
 393	}
 394
 395	status = ocfs2_journal_access_gd(handle,
 396					 INODE_CACHE(alloc_inode),
 397					 bg_bh,
 398					 OCFS2_JOURNAL_ACCESS_CREATE);
 399	if (status < 0) {
 400		mlog_errno(status);
 401		goto bail;
 402	}
 403
 404	memset(bg, 0, sb->s_blocksize);
 405	strcpy(bg->bg_signature, OCFS2_GROUP_DESC_SIGNATURE);
 406	bg->bg_generation = cpu_to_le32(OCFS2_SB(sb)->fs_generation);
 407	bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb, 1,
 408						osb->s_feature_incompat));
 409	bg->bg_chain = cpu_to_le16(my_chain);
 410	bg->bg_next_group = cl->cl_recs[my_chain].c_blkno;
 411	bg->bg_parent_dinode = cpu_to_le64(OCFS2_I(alloc_inode)->ip_blkno);
 412	bg->bg_blkno = cpu_to_le64(group_blkno);
 413	if (group_clusters == le16_to_cpu(cl->cl_cpg))
 414		bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
 415	else
 416		ocfs2_bg_discontig_add_extent(osb, bg, cl, group_blkno,
 417					      group_clusters);
 418
 419	/* set the 1st bit in the bitmap to account for the descriptor block */
 420	ocfs2_set_bit(0, (unsigned long *)bg->bg_bitmap);
 421	bg->bg_free_bits_count = cpu_to_le16(le16_to_cpu(bg->bg_bits) - 1);
 422
 423	ocfs2_journal_dirty(handle, bg_bh);
 424
 425	/* There is no need to zero out or otherwise initialize the
 426	 * other blocks in a group - All valid FS metadata in a block
 427	 * group stores the superblock fs_generation value at
 428	 * allocation time. */
 429
 430bail:
 431	if (status)
 432		mlog_errno(status);
 433	return status;
 434}
 435
 436static inline u16 ocfs2_find_smallest_chain(struct ocfs2_chain_list *cl)
 437{
 438	u16 curr, best;
 439
 440	best = curr = 0;
 441	while (curr < le16_to_cpu(cl->cl_count)) {
 442		if (le32_to_cpu(cl->cl_recs[best].c_total) >
 443		    le32_to_cpu(cl->cl_recs[curr].c_total))
 444			best = curr;
 445		curr++;
 446	}
 447	return best;
 448}
 449
 450static struct buffer_head *
 451ocfs2_block_group_alloc_contig(struct ocfs2_super *osb, handle_t *handle,
 452			       struct inode *alloc_inode,
 453			       struct ocfs2_alloc_context *ac,
 454			       struct ocfs2_chain_list *cl)
 455{
 456	int status;
 457	u32 bit_off, num_bits;
 458	u64 bg_blkno;
 459	struct buffer_head *bg_bh;
 460	unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
 461
 462	status = ocfs2_claim_clusters(handle, ac,
 463				      le16_to_cpu(cl->cl_cpg), &bit_off,
 464				      &num_bits);
 465	if (status < 0) {
 466		if (status != -ENOSPC)
 467			mlog_errno(status);
 468		goto bail;
 469	}
 470
 471	/* setup the group */
 472	bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 473	trace_ocfs2_block_group_alloc_contig(
 474	     (unsigned long long)bg_blkno, alloc_rec);
 475
 476	bg_bh = sb_getblk(osb->sb, bg_blkno);
 477	if (!bg_bh) {
 478		status = -ENOMEM;
 479		mlog_errno(status);
 480		goto bail;
 481	}
 482	ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
 483
 484	status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
 485					bg_blkno, num_bits, alloc_rec, cl);
 486	if (status < 0) {
 487		brelse(bg_bh);
 488		mlog_errno(status);
 489	}
 490
 491bail:
 492	return status ? ERR_PTR(status) : bg_bh;
 493}
 494
 495static int ocfs2_block_group_claim_bits(struct ocfs2_super *osb,
 496					handle_t *handle,
 497					struct ocfs2_alloc_context *ac,
 498					unsigned int min_bits,
 499					u32 *bit_off, u32 *num_bits)
 500{
 501	int status = 0;
 502
 503	while (min_bits) {
 504		status = ocfs2_claim_clusters(handle, ac, min_bits,
 505					      bit_off, num_bits);
 506		if (status != -ENOSPC)
 507			break;
 508
 509		min_bits >>= 1;
 510	}
 511
 512	return status;
 513}
 514
 515static int ocfs2_block_group_grow_discontig(handle_t *handle,
 516					    struct inode *alloc_inode,
 517					    struct buffer_head *bg_bh,
 518					    struct ocfs2_alloc_context *ac,
 519					    struct ocfs2_chain_list *cl,
 520					    unsigned int min_bits)
 521{
 522	int status;
 523	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 524	struct ocfs2_group_desc *bg =
 525		(struct ocfs2_group_desc *)bg_bh->b_data;
 526	unsigned int needed = le16_to_cpu(cl->cl_cpg) -
 527			 le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
 528	u32 p_cpos, clusters;
 529	u64 p_blkno;
 530	struct ocfs2_extent_list *el = &bg->bg_list;
 531
 532	status = ocfs2_journal_access_gd(handle,
 533					 INODE_CACHE(alloc_inode),
 534					 bg_bh,
 535					 OCFS2_JOURNAL_ACCESS_CREATE);
 536	if (status < 0) {
 537		mlog_errno(status);
 538		goto bail;
 539	}
 540
 541	while ((needed > 0) && (le16_to_cpu(el->l_next_free_rec) <
 542				le16_to_cpu(el->l_count))) {
 543		if (min_bits > needed)
 544			min_bits = needed;
 545		status = ocfs2_block_group_claim_bits(osb, handle, ac,
 546						      min_bits, &p_cpos,
 547						      &clusters);
 548		if (status < 0) {
 549			if (status != -ENOSPC)
 550				mlog_errno(status);
 551			goto bail;
 552		}
 553		p_blkno = ocfs2_clusters_to_blocks(osb->sb, p_cpos);
 554		ocfs2_bg_discontig_add_extent(osb, bg, cl, p_blkno,
 555					      clusters);
 556
 557		min_bits = clusters;
 558		needed = le16_to_cpu(cl->cl_cpg) -
 559			 le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
 560	}
 561
 562	if (needed > 0) {
 563		/*
 564		 * We have used up all the extent rec but can't fill up
 565		 * the cpg. So bail out.
 566		 */
 567		status = -ENOSPC;
 568		goto bail;
 569	}
 570
 571	ocfs2_journal_dirty(handle, bg_bh);
 572
 573bail:
 574	return status;
 575}
 576
 577static void ocfs2_bg_alloc_cleanup(handle_t *handle,
 578				   struct ocfs2_alloc_context *cluster_ac,
 579				   struct inode *alloc_inode,
 580				   struct buffer_head *bg_bh)
 581{
 582	int i, ret;
 583	struct ocfs2_group_desc *bg;
 584	struct ocfs2_extent_list *el;
 585	struct ocfs2_extent_rec *rec;
 586
 587	if (!bg_bh)
 588		return;
 589
 590	bg = (struct ocfs2_group_desc *)bg_bh->b_data;
 591	el = &bg->bg_list;
 592	for (i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
 593		rec = &el->l_recs[i];
 594		ret = ocfs2_free_clusters(handle, cluster_ac->ac_inode,
 595					  cluster_ac->ac_bh,
 596					  le64_to_cpu(rec->e_blkno),
 597					  le16_to_cpu(rec->e_leaf_clusters));
 598		if (ret)
 599			mlog_errno(ret);
 600		/* Try all the clusters to free */
 601	}
 602
 603	ocfs2_remove_from_cache(INODE_CACHE(alloc_inode), bg_bh);
 604	brelse(bg_bh);
 605}
 606
 607static struct buffer_head *
 608ocfs2_block_group_alloc_discontig(handle_t *handle,
 609				  struct inode *alloc_inode,
 610				  struct ocfs2_alloc_context *ac,
 611				  struct ocfs2_chain_list *cl)
 612{
 613	int status;
 614	u32 bit_off, num_bits;
 615	u64 bg_blkno;
 616	unsigned int min_bits = le16_to_cpu(cl->cl_cpg) >> 1;
 617	struct buffer_head *bg_bh = NULL;
 618	unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
 619	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 620
 621	if (!ocfs2_supports_discontig_bg(osb)) {
 622		status = -ENOSPC;
 623		goto bail;
 624	}
 625
 626	status = ocfs2_extend_trans(handle,
 627				    ocfs2_calc_bg_discontig_credits(osb->sb));
 628	if (status) {
 629		mlog_errno(status);
 630		goto bail;
 631	}
 632
 633	/*
 634	 * We're going to be grabbing from multiple cluster groups.
 635	 * We don't have enough credits to relink them all, and the
 636	 * cluster groups will be staying in cache for the duration of
 637	 * this operation.
 638	 */
 639	ac->ac_disable_chain_relink = 1;
 640
 641	/* Claim the first region */
 642	status = ocfs2_block_group_claim_bits(osb, handle, ac, min_bits,
 643					      &bit_off, &num_bits);
 644	if (status < 0) {
 645		if (status != -ENOSPC)
 646			mlog_errno(status);
 647		goto bail;
 648	}
 649	min_bits = num_bits;
 650
 651	/* setup the group */
 652	bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 653	trace_ocfs2_block_group_alloc_discontig(
 654				(unsigned long long)bg_blkno, alloc_rec);
 655
 656	bg_bh = sb_getblk(osb->sb, bg_blkno);
 657	if (!bg_bh) {
 658		status = -ENOMEM;
 659		mlog_errno(status);
 660		goto bail;
 661	}
 662	ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
 663
 664	status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
 665					bg_blkno, num_bits, alloc_rec, cl);
 666	if (status < 0) {
 667		mlog_errno(status);
 668		goto bail;
 669	}
 670
 671	status = ocfs2_block_group_grow_discontig(handle, alloc_inode,
 672						  bg_bh, ac, cl, min_bits);
 673	if (status)
 674		mlog_errno(status);
 675
 676bail:
 677	if (status)
 678		ocfs2_bg_alloc_cleanup(handle, ac, alloc_inode, bg_bh);
 679	return status ? ERR_PTR(status) : bg_bh;
 680}
 681
 682/*
 683 * We expect the block group allocator to already be locked.
 684 */
 685static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
 686				   struct inode *alloc_inode,
 687				   struct buffer_head *bh,
 688				   u64 max_block,
 689				   u64 *last_alloc_group,
 690				   int flags)
 691{
 692	int status, credits;
 693	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) bh->b_data;
 694	struct ocfs2_chain_list *cl;
 695	struct ocfs2_alloc_context *ac = NULL;
 696	handle_t *handle = NULL;
 697	u16 alloc_rec;
 698	struct buffer_head *bg_bh = NULL;
 699	struct ocfs2_group_desc *bg;
 700
 701	BUG_ON(ocfs2_is_cluster_bitmap(alloc_inode));
 702
 703	cl = &fe->id2.i_chain;
 704	status = ocfs2_reserve_clusters_with_limit(osb,
 705						   le16_to_cpu(cl->cl_cpg),
 706						   max_block, flags, &ac);
 707	if (status < 0) {
 708		if (status != -ENOSPC)
 709			mlog_errno(status);
 710		goto bail;
 711	}
 712
 713	credits = ocfs2_calc_group_alloc_credits(osb->sb,
 714						 le16_to_cpu(cl->cl_cpg));
 715	handle = ocfs2_start_trans(osb, credits);
 716	if (IS_ERR(handle)) {
 717		status = PTR_ERR(handle);
 718		handle = NULL;
 719		mlog_errno(status);
 720		goto bail;
 721	}
 722
 723	if (last_alloc_group && *last_alloc_group != 0) {
 724		trace_ocfs2_block_group_alloc(
 725				(unsigned long long)*last_alloc_group);
 726		ac->ac_last_group = *last_alloc_group;
 727	}
 728
 729	bg_bh = ocfs2_block_group_alloc_contig(osb, handle, alloc_inode,
 730					       ac, cl);
 731	if (IS_ERR(bg_bh) && (PTR_ERR(bg_bh) == -ENOSPC))
 732		bg_bh = ocfs2_block_group_alloc_discontig(handle,
 733							  alloc_inode,
 734							  ac, cl);
 735	if (IS_ERR(bg_bh)) {
 736		status = PTR_ERR(bg_bh);
 737		bg_bh = NULL;
 738		if (status != -ENOSPC)
 739			mlog_errno(status);
 740		goto bail;
 741	}
 742	bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 743
 744	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
 745					 bh, OCFS2_JOURNAL_ACCESS_WRITE);
 746	if (status < 0) {
 747		mlog_errno(status);
 748		goto bail;
 749	}
 750
 751	alloc_rec = le16_to_cpu(bg->bg_chain);
 752	le32_add_cpu(&cl->cl_recs[alloc_rec].c_free,
 753		     le16_to_cpu(bg->bg_free_bits_count));
 754	le32_add_cpu(&cl->cl_recs[alloc_rec].c_total,
 755		     le16_to_cpu(bg->bg_bits));
 756	cl->cl_recs[alloc_rec].c_blkno = bg->bg_blkno;
 757	if (le16_to_cpu(cl->cl_next_free_rec) < le16_to_cpu(cl->cl_count))
 758		le16_add_cpu(&cl->cl_next_free_rec, 1);
 759
 760	le32_add_cpu(&fe->id1.bitmap1.i_used, le16_to_cpu(bg->bg_bits) -
 761					le16_to_cpu(bg->bg_free_bits_count));
 762	le32_add_cpu(&fe->id1.bitmap1.i_total, le16_to_cpu(bg->bg_bits));
 763	le32_add_cpu(&fe->i_clusters, le16_to_cpu(cl->cl_cpg));
 764
 765	ocfs2_journal_dirty(handle, bh);
 766
 767	spin_lock(&OCFS2_I(alloc_inode)->ip_lock);
 768	OCFS2_I(alloc_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
 769	fe->i_size = cpu_to_le64(ocfs2_clusters_to_bytes(alloc_inode->i_sb,
 770					     le32_to_cpu(fe->i_clusters)));
 771	spin_unlock(&OCFS2_I(alloc_inode)->ip_lock);
 772	i_size_write(alloc_inode, le64_to_cpu(fe->i_size));
 773	alloc_inode->i_blocks = ocfs2_inode_sector_count(alloc_inode);
 774	ocfs2_update_inode_fsync_trans(handle, alloc_inode, 0);
 775
 776	status = 0;
 777
 778	/* save the new last alloc group so that the caller can cache it. */
 779	if (last_alloc_group)
 780		*last_alloc_group = ac->ac_last_group;
 781
 782bail:
 783	if (handle)
 784		ocfs2_commit_trans(osb, handle);
 785
 786	if (ac)
 787		ocfs2_free_alloc_context(ac);
 788
 789	brelse(bg_bh);
 790
 791	if (status)
 792		mlog_errno(status);
 793	return status;
 794}
 795
 796static int ocfs2_reserve_suballoc_bits(struct ocfs2_super *osb,
 797				       struct ocfs2_alloc_context *ac,
 798				       int type,
 799				       u32 slot,
 800				       u64 *last_alloc_group,
 801				       int flags)
 802{
 803	int status;
 804	u32 bits_wanted = ac->ac_bits_wanted;
 805	struct inode *alloc_inode;
 806	struct buffer_head *bh = NULL;
 807	struct ocfs2_dinode *fe;
 808	u32 free_bits;
 809
 810	alloc_inode = ocfs2_get_system_file_inode(osb, type, slot);
 811	if (!alloc_inode) {
 812		mlog_errno(-EINVAL);
 813		return -EINVAL;
 814	}
 815
 816	mutex_lock(&alloc_inode->i_mutex);
 817
 818	status = ocfs2_inode_lock(alloc_inode, &bh, 1);
 819	if (status < 0) {
 820		mutex_unlock(&alloc_inode->i_mutex);
 821		iput(alloc_inode);
 822
 823		mlog_errno(status);
 824		return status;
 825	}
 826
 827	ac->ac_inode = alloc_inode;
 828	ac->ac_alloc_slot = slot;
 829
 830	fe = (struct ocfs2_dinode *) bh->b_data;
 831
 832	/* The bh was validated by the inode read inside
 833	 * ocfs2_inode_lock().  Any corruption is a code bug. */
 834	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
 835
 836	if (!(fe->i_flags & cpu_to_le32(OCFS2_CHAIN_FL))) {
 837		ocfs2_error(alloc_inode->i_sb, "Invalid chain allocator %llu",
 838			    (unsigned long long)le64_to_cpu(fe->i_blkno));
 839		status = -EIO;
 840		goto bail;
 841	}
 842
 843	free_bits = le32_to_cpu(fe->id1.bitmap1.i_total) -
 844		le32_to_cpu(fe->id1.bitmap1.i_used);
 845
 846	if (bits_wanted > free_bits) {
 847		/* cluster bitmap never grows */
 848		if (ocfs2_is_cluster_bitmap(alloc_inode)) {
 849			trace_ocfs2_reserve_suballoc_bits_nospc(bits_wanted,
 850								free_bits);
 851			status = -ENOSPC;
 852			goto bail;
 853		}
 854
 855		if (!(flags & ALLOC_NEW_GROUP)) {
 856			trace_ocfs2_reserve_suballoc_bits_no_new_group(
 857						slot, bits_wanted, free_bits);
 858			status = -ENOSPC;
 859			goto bail;
 860		}
 861
 862		status = ocfs2_block_group_alloc(osb, alloc_inode, bh,
 863						 ac->ac_max_block,
 864						 last_alloc_group, flags);
 865		if (status < 0) {
 866			if (status != -ENOSPC)
 867				mlog_errno(status);
 868			goto bail;
 869		}
 870		atomic_inc(&osb->alloc_stats.bg_extends);
 871
 872		/* You should never ask for this much metadata */
 873		BUG_ON(bits_wanted >
 874		       (le32_to_cpu(fe->id1.bitmap1.i_total)
 875			- le32_to_cpu(fe->id1.bitmap1.i_used)));
 876	}
 877
 878	get_bh(bh);
 879	ac->ac_bh = bh;
 880bail:
 881	brelse(bh);
 882
 883	if (status)
 884		mlog_errno(status);
 885	return status;
 886}
 887
 888static void ocfs2_init_inode_steal_slot(struct ocfs2_super *osb)
 889{
 890	spin_lock(&osb->osb_lock);
 891	osb->s_inode_steal_slot = OCFS2_INVALID_SLOT;
 892	spin_unlock(&osb->osb_lock);
 893	atomic_set(&osb->s_num_inodes_stolen, 0);
 894}
 895
 896static void ocfs2_init_meta_steal_slot(struct ocfs2_super *osb)
 897{
 898	spin_lock(&osb->osb_lock);
 899	osb->s_meta_steal_slot = OCFS2_INVALID_SLOT;
 900	spin_unlock(&osb->osb_lock);
 901	atomic_set(&osb->s_num_meta_stolen, 0);
 902}
 903
 904void ocfs2_init_steal_slots(struct ocfs2_super *osb)
 905{
 906	ocfs2_init_inode_steal_slot(osb);
 907	ocfs2_init_meta_steal_slot(osb);
 908}
 909
 910static void __ocfs2_set_steal_slot(struct ocfs2_super *osb, int slot, int type)
 911{
 912	spin_lock(&osb->osb_lock);
 913	if (type == INODE_ALLOC_SYSTEM_INODE)
 914		osb->s_inode_steal_slot = slot;
 915	else if (type == EXTENT_ALLOC_SYSTEM_INODE)
 916		osb->s_meta_steal_slot = slot;
 917	spin_unlock(&osb->osb_lock);
 918}
 919
 920static int __ocfs2_get_steal_slot(struct ocfs2_super *osb, int type)
 921{
 922	int slot = OCFS2_INVALID_SLOT;
 923
 924	spin_lock(&osb->osb_lock);
 925	if (type == INODE_ALLOC_SYSTEM_INODE)
 926		slot = osb->s_inode_steal_slot;
 927	else if (type == EXTENT_ALLOC_SYSTEM_INODE)
 928		slot = osb->s_meta_steal_slot;
 929	spin_unlock(&osb->osb_lock);
 930
 931	return slot;
 932}
 933
 934static int ocfs2_get_inode_steal_slot(struct ocfs2_super *osb)
 935{
 936	return __ocfs2_get_steal_slot(osb, INODE_ALLOC_SYSTEM_INODE);
 937}
 938
 939static int ocfs2_get_meta_steal_slot(struct ocfs2_super *osb)
 940{
 941	return __ocfs2_get_steal_slot(osb, EXTENT_ALLOC_SYSTEM_INODE);
 942}
 943
 944static int ocfs2_steal_resource(struct ocfs2_super *osb,
 945				struct ocfs2_alloc_context *ac,
 946				int type)
 947{
 948	int i, status = -ENOSPC;
 949	int slot = __ocfs2_get_steal_slot(osb, type);
 950
 951	/* Start to steal resource from the first slot after ours. */
 952	if (slot == OCFS2_INVALID_SLOT)
 953		slot = osb->slot_num + 1;
 954
 955	for (i = 0; i < osb->max_slots; i++, slot++) {
 956		if (slot == osb->max_slots)
 957			slot = 0;
 958
 959		if (slot == osb->slot_num)
 960			continue;
 961
 962		status = ocfs2_reserve_suballoc_bits(osb, ac,
 963						     type,
 964						     (u32)slot, NULL,
 965						     NOT_ALLOC_NEW_GROUP);
 966		if (status >= 0) {
 967			__ocfs2_set_steal_slot(osb, slot, type);
 968			break;
 969		}
 970
 971		ocfs2_free_ac_resource(ac);
 972	}
 973
 974	return status;
 975}
 976
 977static int ocfs2_steal_inode(struct ocfs2_super *osb,
 978			     struct ocfs2_alloc_context *ac)
 979{
 980	return ocfs2_steal_resource(osb, ac, INODE_ALLOC_SYSTEM_INODE);
 981}
 982
 983static int ocfs2_steal_meta(struct ocfs2_super *osb,
 984			    struct ocfs2_alloc_context *ac)
 985{
 986	return ocfs2_steal_resource(osb, ac, EXTENT_ALLOC_SYSTEM_INODE);
 987}
 988
 989int ocfs2_reserve_new_metadata_blocks(struct ocfs2_super *osb,
 990				      int blocks,
 991				      struct ocfs2_alloc_context **ac)
 992{
 993	int status;
 994	int slot = ocfs2_get_meta_steal_slot(osb);
 995
 996	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 997	if (!(*ac)) {
 998		status = -ENOMEM;
 999		mlog_errno(status);
1000		goto bail;
1001	}
1002
1003	(*ac)->ac_bits_wanted = blocks;
1004	(*ac)->ac_which = OCFS2_AC_USE_META;
1005	(*ac)->ac_group_search = ocfs2_block_group_search;
1006
1007	if (slot != OCFS2_INVALID_SLOT &&
1008		atomic_read(&osb->s_num_meta_stolen) < OCFS2_MAX_TO_STEAL)
1009		goto extent_steal;
1010
1011	atomic_set(&osb->s_num_meta_stolen, 0);
1012	status = ocfs2_reserve_suballoc_bits(osb, (*ac),
1013					     EXTENT_ALLOC_SYSTEM_INODE,
1014					     (u32)osb->slot_num, NULL,
1015					     ALLOC_GROUPS_FROM_GLOBAL|ALLOC_NEW_GROUP);
1016
1017
1018	if (status >= 0) {
1019		status = 0;
1020		if (slot != OCFS2_INVALID_SLOT)
1021			ocfs2_init_meta_steal_slot(osb);
1022		goto bail;
1023	} else if (status < 0 && status != -ENOSPC) {
1024		mlog_errno(status);
1025		goto bail;
1026	}
1027
1028	ocfs2_free_ac_resource(*ac);
1029
1030extent_steal:
1031	status = ocfs2_steal_meta(osb, *ac);
1032	atomic_inc(&osb->s_num_meta_stolen);
1033	if (status < 0) {
1034		if (status != -ENOSPC)
1035			mlog_errno(status);
1036		goto bail;
1037	}
1038
1039	status = 0;
1040bail:
1041	if ((status < 0) && *ac) {
1042		ocfs2_free_alloc_context(*ac);
1043		*ac = NULL;
1044	}
1045
1046	if (status)
1047		mlog_errno(status);
1048	return status;
1049}
1050
1051int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
1052			       struct ocfs2_extent_list *root_el,
1053			       struct ocfs2_alloc_context **ac)
1054{
1055	return ocfs2_reserve_new_metadata_blocks(osb,
1056					ocfs2_extend_meta_needed(root_el),
1057					ac);
1058}
1059
1060int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
1061			    struct ocfs2_alloc_context **ac)
1062{
1063	int status;
1064	int slot = ocfs2_get_inode_steal_slot(osb);
1065	u64 alloc_group;
1066
1067	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1068	if (!(*ac)) {
1069		status = -ENOMEM;
1070		mlog_errno(status);
1071		goto bail;
1072	}
1073
1074	(*ac)->ac_bits_wanted = 1;
1075	(*ac)->ac_which = OCFS2_AC_USE_INODE;
1076
1077	(*ac)->ac_group_search = ocfs2_block_group_search;
1078
1079	/*
1080	 * stat(2) can't handle i_ino > 32bits, so we tell the
1081	 * lower levels not to allocate us a block group past that
1082	 * limit.  The 'inode64' mount option avoids this behavior.
1083	 */
1084	if (!(osb->s_mount_opt & OCFS2_MOUNT_INODE64))
1085		(*ac)->ac_max_block = (u32)~0U;
1086
1087	/*
1088	 * slot is set when we successfully steal inode from other nodes.
1089	 * It is reset in 3 places:
1090	 * 1. when we flush the truncate log
1091	 * 2. when we complete local alloc recovery.
1092	 * 3. when we successfully allocate from our own slot.
1093	 * After it is set, we will go on stealing inodes until we find the
1094	 * need to check our slots to see whether there is some space for us.
1095	 */
1096	if (slot != OCFS2_INVALID_SLOT &&
1097	    atomic_read(&osb->s_num_inodes_stolen) < OCFS2_MAX_TO_STEAL)
1098		goto inode_steal;
1099
1100	atomic_set(&osb->s_num_inodes_stolen, 0);
1101	alloc_group = osb->osb_inode_alloc_group;
1102	status = ocfs2_reserve_suballoc_bits(osb, *ac,
1103					     INODE_ALLOC_SYSTEM_INODE,
1104					     (u32)osb->slot_num,
1105					     &alloc_group,
1106					     ALLOC_NEW_GROUP |
1107					     ALLOC_GROUPS_FROM_GLOBAL);
1108	if (status >= 0) {
1109		status = 0;
1110
1111		spin_lock(&osb->osb_lock);
1112		osb->osb_inode_alloc_group = alloc_group;
1113		spin_unlock(&osb->osb_lock);
1114		trace_ocfs2_reserve_new_inode_new_group(
1115			(unsigned long long)alloc_group);
1116
1117		/*
1118		 * Some inodes must be freed by us, so try to allocate
1119		 * from our own next time.
1120		 */
1121		if (slot != OCFS2_INVALID_SLOT)
1122			ocfs2_init_inode_steal_slot(osb);
1123		goto bail;
1124	} else if (status < 0 && status != -ENOSPC) {
1125		mlog_errno(status);
1126		goto bail;
1127	}
1128
1129	ocfs2_free_ac_resource(*ac);
1130
1131inode_steal:
1132	status = ocfs2_steal_inode(osb, *ac);
1133	atomic_inc(&osb->s_num_inodes_stolen);
1134	if (status < 0) {
1135		if (status != -ENOSPC)
1136			mlog_errno(status);
1137		goto bail;
1138	}
1139
1140	status = 0;
1141bail:
1142	if ((status < 0) && *ac) {
1143		ocfs2_free_alloc_context(*ac);
1144		*ac = NULL;
1145	}
1146
1147	if (status)
1148		mlog_errno(status);
1149	return status;
1150}
1151
1152/* local alloc code has to do the same thing, so rather than do this
1153 * twice.. */
1154int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
1155				      struct ocfs2_alloc_context *ac)
1156{
1157	int status;
1158
1159	ac->ac_which = OCFS2_AC_USE_MAIN;
1160	ac->ac_group_search = ocfs2_cluster_group_search;
1161
1162	status = ocfs2_reserve_suballoc_bits(osb, ac,
1163					     GLOBAL_BITMAP_SYSTEM_INODE,
1164					     OCFS2_INVALID_SLOT, NULL,
1165					     ALLOC_NEW_GROUP);
1166	if (status < 0 && status != -ENOSPC) {
1167		mlog_errno(status);
1168		goto bail;
1169	}
1170
1171bail:
1172	return status;
1173}
1174
1175/* Callers don't need to care which bitmap (local alloc or main) to
1176 * use so we figure it out for them, but unfortunately this clutters
1177 * things a bit. */
1178static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
1179					     u32 bits_wanted, u64 max_block,
1180					     int flags,
1181					     struct ocfs2_alloc_context **ac)
1182{
1183	int status;
 
1184
1185	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1186	if (!(*ac)) {
1187		status = -ENOMEM;
1188		mlog_errno(status);
1189		goto bail;
1190	}
1191
1192	(*ac)->ac_bits_wanted = bits_wanted;
1193	(*ac)->ac_max_block = max_block;
1194
1195	status = -ENOSPC;
1196	if (!(flags & ALLOC_GROUPS_FROM_GLOBAL) &&
1197	    ocfs2_alloc_should_use_local(osb, bits_wanted)) {
1198		status = ocfs2_reserve_local_alloc_bits(osb,
1199							bits_wanted,
1200							*ac);
1201		if ((status < 0) && (status != -ENOSPC)) {
1202			mlog_errno(status);
1203			goto bail;
1204		}
1205	}
1206
1207	if (status == -ENOSPC) {
 
1208		status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1209		if (status < 0) {
1210			if (status != -ENOSPC)
1211				mlog_errno(status);
1212			goto bail;
1213		}
1214	}
1215
1216	status = 0;
1217bail:
1218	if ((status < 0) && *ac) {
1219		ocfs2_free_alloc_context(*ac);
1220		*ac = NULL;
1221	}
1222
1223	if (status)
1224		mlog_errno(status);
1225	return status;
1226}
1227
1228int ocfs2_reserve_clusters(struct ocfs2_super *osb,
1229			   u32 bits_wanted,
1230			   struct ocfs2_alloc_context **ac)
1231{
1232	return ocfs2_reserve_clusters_with_limit(osb, bits_wanted, 0,
1233						 ALLOC_NEW_GROUP, ac);
1234}
1235
1236/*
1237 * More or less lifted from ext3. I'll leave their description below:
1238 *
1239 * "For ext3 allocations, we must not reuse any blocks which are
1240 * allocated in the bitmap buffer's "last committed data" copy.  This
1241 * prevents deletes from freeing up the page for reuse until we have
1242 * committed the delete transaction.
1243 *
1244 * If we didn't do this, then deleting something and reallocating it as
1245 * data would allow the old block to be overwritten before the
1246 * transaction committed (because we force data to disk before commit).
1247 * This would lead to corruption if we crashed between overwriting the
1248 * data and committing the delete.
1249 *
1250 * @@@ We may want to make this allocation behaviour conditional on
1251 * data-writes at some point, and disable it for metadata allocations or
1252 * sync-data inodes."
1253 *
1254 * Note: OCFS2 already does this differently for metadata vs data
1255 * allocations, as those bitmaps are separate and undo access is never
1256 * called on a metadata group descriptor.
1257 */
1258static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
1259					 int nr)
1260{
1261	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1262	int ret;
1263
1264	if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
1265		return 0;
1266
1267	if (!buffer_jbd(bg_bh))
1268		return 1;
1269
1270	jbd_lock_bh_state(bg_bh);
1271	bg = (struct ocfs2_group_desc *) bh2jh(bg_bh)->b_committed_data;
1272	if (bg)
1273		ret = !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
1274	else
1275		ret = 1;
1276	jbd_unlock_bh_state(bg_bh);
1277
1278	return ret;
1279}
1280
1281static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
1282					     struct buffer_head *bg_bh,
1283					     unsigned int bits_wanted,
1284					     unsigned int total_bits,
1285					     struct ocfs2_suballoc_result *res)
1286{
1287	void *bitmap;
1288	u16 best_offset, best_size;
1289	int offset, start, found, status = 0;
1290	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1291
1292	/* Callers got this descriptor from
1293	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1294	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1295
1296	found = start = best_offset = best_size = 0;
1297	bitmap = bg->bg_bitmap;
1298
1299	while((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) != -1) {
1300		if (offset == total_bits)
1301			break;
1302
1303		if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
1304			/* We found a zero, but we can't use it as it
1305			 * hasn't been put to disk yet! */
1306			found = 0;
1307			start = offset + 1;
1308		} else if (offset == start) {
1309			/* we found a zero */
1310			found++;
1311			/* move start to the next bit to test */
1312			start++;
1313		} else {
1314			/* got a zero after some ones */
1315			found = 1;
1316			start = offset + 1;
1317		}
1318		if (found > best_size) {
1319			best_size = found;
1320			best_offset = start - found;
1321		}
1322		/* we got everything we needed */
1323		if (found == bits_wanted) {
1324			/* mlog(0, "Found it all!\n"); */
1325			break;
1326		}
1327	}
1328
1329	if (best_size) {
1330		res->sr_bit_offset = best_offset;
1331		res->sr_bits = best_size;
1332	} else {
1333		status = -ENOSPC;
1334		/* No error log here -- see the comment above
1335		 * ocfs2_test_bg_bit_allocatable */
1336	}
1337
1338	return status;
1339}
1340
1341int ocfs2_block_group_set_bits(handle_t *handle,
1342					     struct inode *alloc_inode,
1343					     struct ocfs2_group_desc *bg,
1344					     struct buffer_head *group_bh,
1345					     unsigned int bit_off,
1346					     unsigned int num_bits)
1347{
1348	int status;
1349	void *bitmap = bg->bg_bitmap;
1350	int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1351
1352	/* All callers get the descriptor via
1353	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1354	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1355	BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
1356
1357	trace_ocfs2_block_group_set_bits(bit_off, num_bits);
1358
1359	if (ocfs2_is_cluster_bitmap(alloc_inode))
1360		journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1361
1362	status = ocfs2_journal_access_gd(handle,
1363					 INODE_CACHE(alloc_inode),
1364					 group_bh,
1365					 journal_type);
1366	if (status < 0) {
1367		mlog_errno(status);
1368		goto bail;
1369	}
1370
1371	le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
1372	if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
1373		ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit"
1374			    " count %u but claims %u are freed. num_bits %d",
1375			    (unsigned long long)le64_to_cpu(bg->bg_blkno),
1376			    le16_to_cpu(bg->bg_bits),
1377			    le16_to_cpu(bg->bg_free_bits_count), num_bits);
1378		return -EROFS;
1379	}
1380	while(num_bits--)
1381		ocfs2_set_bit(bit_off++, bitmap);
1382
1383	ocfs2_journal_dirty(handle, group_bh);
1384
1385bail:
1386	return status;
1387}
1388
1389/* find the one with the most empty bits */
1390static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
1391{
1392	u16 curr, best;
1393
1394	BUG_ON(!cl->cl_next_free_rec);
1395
1396	best = curr = 0;
1397	while (curr < le16_to_cpu(cl->cl_next_free_rec)) {
1398		if (le32_to_cpu(cl->cl_recs[curr].c_free) >
1399		    le32_to_cpu(cl->cl_recs[best].c_free))
1400			best = curr;
1401		curr++;
1402	}
1403
1404	BUG_ON(best >= le16_to_cpu(cl->cl_next_free_rec));
1405	return best;
1406}
1407
1408static int ocfs2_relink_block_group(handle_t *handle,
1409				    struct inode *alloc_inode,
1410				    struct buffer_head *fe_bh,
1411				    struct buffer_head *bg_bh,
1412				    struct buffer_head *prev_bg_bh,
1413				    u16 chain)
1414{
1415	int status;
1416	/* there is a really tiny chance the journal calls could fail,
1417	 * but we wouldn't want inconsistent blocks in *any* case. */
1418	u64 bg_ptr, prev_bg_ptr;
1419	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
1420	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1421	struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
1422
1423	/* The caller got these descriptors from
1424	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1425	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1426	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(prev_bg));
1427
1428	trace_ocfs2_relink_block_group(
1429		(unsigned long long)le64_to_cpu(fe->i_blkno), chain,
1430		(unsigned long long)le64_to_cpu(bg->bg_blkno),
1431		(unsigned long long)le64_to_cpu(prev_bg->bg_blkno));
1432
1433	bg_ptr = le64_to_cpu(bg->bg_next_group);
1434	prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
1435
1436	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1437					 prev_bg_bh,
1438					 OCFS2_JOURNAL_ACCESS_WRITE);
1439	if (status < 0)
1440		goto out;
1441
1442	prev_bg->bg_next_group = bg->bg_next_group;
1443	ocfs2_journal_dirty(handle, prev_bg_bh);
1444
1445	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1446					 bg_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1447	if (status < 0)
1448		goto out_rollback_prev_bg;
1449
1450	bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
1451	ocfs2_journal_dirty(handle, bg_bh);
1452
1453	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
1454					 fe_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1455	if (status < 0)
1456		goto out_rollback_bg;
1457
1458	fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
1459	ocfs2_journal_dirty(handle, fe_bh);
1460
1461out:
1462	if (status < 0)
1463		mlog_errno(status);
1464	return status;
1465
1466out_rollback_bg:
1467	bg->bg_next_group = cpu_to_le64(bg_ptr);
1468out_rollback_prev_bg:
1469	prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
1470	goto out;
1471}
1472
1473static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
1474						     u32 wanted)
1475{
1476	return le16_to_cpu(bg->bg_free_bits_count) > wanted;
1477}
1478
1479/* return 0 on success, -ENOSPC to keep searching and any other < 0
1480 * value on error. */
1481static int ocfs2_cluster_group_search(struct inode *inode,
1482				      struct buffer_head *group_bh,
1483				      u32 bits_wanted, u32 min_bits,
1484				      u64 max_block,
1485				      struct ocfs2_suballoc_result *res)
1486{
1487	int search = -ENOSPC;
1488	int ret;
1489	u64 blkoff;
1490	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
1491	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1492	unsigned int max_bits, gd_cluster_off;
1493
1494	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1495
1496	if (gd->bg_free_bits_count) {
1497		max_bits = le16_to_cpu(gd->bg_bits);
1498
1499		/* Tail groups in cluster bitmaps which aren't cpg
1500		 * aligned are prone to partial extension by a failed
1501		 * fs resize. If the file system resize never got to
1502		 * update the dinode cluster count, then we don't want
1503		 * to trust any clusters past it, regardless of what
1504		 * the group descriptor says. */
1505		gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
1506							  le64_to_cpu(gd->bg_blkno));
1507		if ((gd_cluster_off + max_bits) >
1508		    OCFS2_I(inode)->ip_clusters) {
1509			max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
1510			trace_ocfs2_cluster_group_search_wrong_max_bits(
1511				(unsigned long long)le64_to_cpu(gd->bg_blkno),
1512				le16_to_cpu(gd->bg_bits),
1513				OCFS2_I(inode)->ip_clusters, max_bits);
1514		}
1515
1516		ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1517							group_bh, bits_wanted,
1518							max_bits, res);
1519		if (ret)
1520			return ret;
1521
1522		if (max_block) {
1523			blkoff = ocfs2_clusters_to_blocks(inode->i_sb,
1524							  gd_cluster_off +
1525							  res->sr_bit_offset +
1526							  res->sr_bits);
1527			trace_ocfs2_cluster_group_search_max_block(
1528				(unsigned long long)blkoff,
1529				(unsigned long long)max_block);
1530			if (blkoff > max_block)
1531				return -ENOSPC;
1532		}
1533
1534		/* ocfs2_block_group_find_clear_bits() might
1535		 * return success, but we still want to return
1536		 * -ENOSPC unless it found the minimum number
1537		 * of bits. */
1538		if (min_bits <= res->sr_bits)
1539			search = 0; /* success */
1540		else if (res->sr_bits) {
1541			/*
1542			 * Don't show bits which we'll be returning
1543			 * for allocation to the local alloc bitmap.
1544			 */
1545			ocfs2_local_alloc_seen_free_bits(osb, res->sr_bits);
1546		}
1547	}
1548
1549	return search;
1550}
1551
1552static int ocfs2_block_group_search(struct inode *inode,
1553				    struct buffer_head *group_bh,
1554				    u32 bits_wanted, u32 min_bits,
1555				    u64 max_block,
1556				    struct ocfs2_suballoc_result *res)
1557{
1558	int ret = -ENOSPC;
1559	u64 blkoff;
1560	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
1561
1562	BUG_ON(min_bits != 1);
1563	BUG_ON(ocfs2_is_cluster_bitmap(inode));
1564
1565	if (bg->bg_free_bits_count) {
1566		ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1567							group_bh, bits_wanted,
1568							le16_to_cpu(bg->bg_bits),
1569							res);
1570		if (!ret && max_block) {
1571			blkoff = le64_to_cpu(bg->bg_blkno) +
1572				res->sr_bit_offset + res->sr_bits;
1573			trace_ocfs2_block_group_search_max_block(
1574				(unsigned long long)blkoff,
1575				(unsigned long long)max_block);
1576			if (blkoff > max_block)
1577				ret = -ENOSPC;
1578		}
1579	}
1580
1581	return ret;
1582}
1583
1584int ocfs2_alloc_dinode_update_counts(struct inode *inode,
1585				       handle_t *handle,
1586				       struct buffer_head *di_bh,
1587				       u32 num_bits,
1588				       u16 chain)
1589{
1590	int ret;
1591	u32 tmp_used;
1592	struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1593	struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &di->id2.i_chain;
1594
1595	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
1596				      OCFS2_JOURNAL_ACCESS_WRITE);
1597	if (ret < 0) {
1598		mlog_errno(ret);
1599		goto out;
1600	}
1601
1602	tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1603	di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
1604	le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
1605	ocfs2_journal_dirty(handle, di_bh);
1606
1607out:
1608	return ret;
1609}
1610
1611void ocfs2_rollback_alloc_dinode_counts(struct inode *inode,
1612				       struct buffer_head *di_bh,
1613				       u32 num_bits,
1614				       u16 chain)
1615{
1616	u32 tmp_used;
1617	struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1618	struct ocfs2_chain_list *cl;
1619
1620	cl = (struct ocfs2_chain_list *)&di->id2.i_chain;
1621	tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1622	di->id1.bitmap1.i_used = cpu_to_le32(tmp_used - num_bits);
1623	le32_add_cpu(&cl->cl_recs[chain].c_free, num_bits);
1624}
1625
1626static int ocfs2_bg_discontig_fix_by_rec(struct ocfs2_suballoc_result *res,
1627					 struct ocfs2_extent_rec *rec,
1628					 struct ocfs2_chain_list *cl)
1629{
1630	unsigned int bpc = le16_to_cpu(cl->cl_bpc);
1631	unsigned int bitoff = le32_to_cpu(rec->e_cpos) * bpc;
1632	unsigned int bitcount = le16_to_cpu(rec->e_leaf_clusters) * bpc;
1633
1634	if (res->sr_bit_offset < bitoff)
1635		return 0;
1636	if (res->sr_bit_offset >= (bitoff + bitcount))
1637		return 0;
1638	res->sr_blkno = le64_to_cpu(rec->e_blkno) +
1639		(res->sr_bit_offset - bitoff);
1640	if ((res->sr_bit_offset + res->sr_bits) > (bitoff + bitcount))
1641		res->sr_bits = (bitoff + bitcount) - res->sr_bit_offset;
1642	return 1;
1643}
1644
1645static void ocfs2_bg_discontig_fix_result(struct ocfs2_alloc_context *ac,
1646					  struct ocfs2_group_desc *bg,
1647					  struct ocfs2_suballoc_result *res)
1648{
1649	int i;
1650	u64 bg_blkno = res->sr_bg_blkno;  /* Save off */
1651	struct ocfs2_extent_rec *rec;
1652	struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1653	struct ocfs2_chain_list *cl = &di->id2.i_chain;
1654
1655	if (ocfs2_is_cluster_bitmap(ac->ac_inode)) {
1656		res->sr_blkno = 0;
1657		return;
1658	}
1659
1660	res->sr_blkno = res->sr_bg_blkno + res->sr_bit_offset;
1661	res->sr_bg_blkno = 0;  /* Clear it for contig block groups */
1662	if (!ocfs2_supports_discontig_bg(OCFS2_SB(ac->ac_inode->i_sb)) ||
1663	    !bg->bg_list.l_next_free_rec)
1664		return;
1665
1666	for (i = 0; i < le16_to_cpu(bg->bg_list.l_next_free_rec); i++) {
1667		rec = &bg->bg_list.l_recs[i];
1668		if (ocfs2_bg_discontig_fix_by_rec(res, rec, cl)) {
1669			res->sr_bg_blkno = bg_blkno;  /* Restore */
1670			break;
1671		}
1672	}
1673}
1674
1675static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
1676				  handle_t *handle,
1677				  u32 bits_wanted,
1678				  u32 min_bits,
1679				  struct ocfs2_suballoc_result *res,
1680				  u16 *bits_left)
1681{
1682	int ret;
1683	struct buffer_head *group_bh = NULL;
1684	struct ocfs2_group_desc *gd;
1685	struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1686	struct inode *alloc_inode = ac->ac_inode;
1687
1688	ret = ocfs2_read_group_descriptor(alloc_inode, di,
1689					  res->sr_bg_blkno, &group_bh);
1690	if (ret < 0) {
1691		mlog_errno(ret);
1692		return ret;
1693	}
1694
1695	gd = (struct ocfs2_group_desc *) group_bh->b_data;
1696	ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
1697				  ac->ac_max_block, res);
1698	if (ret < 0) {
1699		if (ret != -ENOSPC)
1700			mlog_errno(ret);
1701		goto out;
1702	}
1703
1704	if (!ret)
1705		ocfs2_bg_discontig_fix_result(ac, gd, res);
1706
1707	/*
1708	 * sr_bg_blkno might have been changed by
1709	 * ocfs2_bg_discontig_fix_result
1710	 */
1711	res->sr_bg_stable_blkno = group_bh->b_blocknr;
1712
1713	if (ac->ac_find_loc_only)
1714		goto out_loc_only;
1715
1716	ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
1717					       res->sr_bits,
1718					       le16_to_cpu(gd->bg_chain));
1719	if (ret < 0) {
1720		mlog_errno(ret);
1721		goto out;
1722	}
1723
1724	ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
1725					 res->sr_bit_offset, res->sr_bits);
1726	if (ret < 0) {
1727		ocfs2_rollback_alloc_dinode_counts(alloc_inode, ac->ac_bh,
1728					       res->sr_bits,
1729					       le16_to_cpu(gd->bg_chain));
1730		mlog_errno(ret);
1731	}
1732
1733out_loc_only:
1734	*bits_left = le16_to_cpu(gd->bg_free_bits_count);
1735
1736out:
1737	brelse(group_bh);
1738
1739	return ret;
1740}
1741
1742static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
1743			      handle_t *handle,
1744			      u32 bits_wanted,
1745			      u32 min_bits,
1746			      struct ocfs2_suballoc_result *res,
1747			      u16 *bits_left)
1748{
1749	int status;
1750	u16 chain;
1751	u64 next_group;
1752	struct inode *alloc_inode = ac->ac_inode;
1753	struct buffer_head *group_bh = NULL;
1754	struct buffer_head *prev_group_bh = NULL;
1755	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1756	struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1757	struct ocfs2_group_desc *bg;
1758
1759	chain = ac->ac_chain;
1760	trace_ocfs2_search_chain_begin(
1761		(unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
1762		bits_wanted, chain);
1763
1764	status = ocfs2_read_group_descriptor(alloc_inode, fe,
1765					     le64_to_cpu(cl->cl_recs[chain].c_blkno),
1766					     &group_bh);
1767	if (status < 0) {
1768		mlog_errno(status);
1769		goto bail;
1770	}
1771	bg = (struct ocfs2_group_desc *) group_bh->b_data;
1772
1773	status = -ENOSPC;
1774	/* for now, the chain search is a bit simplistic. We just use
1775	 * the 1st group with any empty bits. */
1776	while ((status = ac->ac_group_search(alloc_inode, group_bh,
1777					     bits_wanted, min_bits,
1778					     ac->ac_max_block,
1779					     res)) == -ENOSPC) {
1780		if (!bg->bg_next_group)
1781			break;
1782
1783		brelse(prev_group_bh);
1784		prev_group_bh = NULL;
1785
1786		next_group = le64_to_cpu(bg->bg_next_group);
1787		prev_group_bh = group_bh;
1788		group_bh = NULL;
1789		status = ocfs2_read_group_descriptor(alloc_inode, fe,
1790						     next_group, &group_bh);
1791		if (status < 0) {
1792			mlog_errno(status);
1793			goto bail;
1794		}
1795		bg = (struct ocfs2_group_desc *) group_bh->b_data;
1796	}
1797	if (status < 0) {
1798		if (status != -ENOSPC)
1799			mlog_errno(status);
1800		goto bail;
1801	}
1802
1803	trace_ocfs2_search_chain_succ(
1804		(unsigned long long)le64_to_cpu(bg->bg_blkno), res->sr_bits);
1805
1806	res->sr_bg_blkno = le64_to_cpu(bg->bg_blkno);
1807
1808	BUG_ON(res->sr_bits == 0);
1809	if (!status)
1810		ocfs2_bg_discontig_fix_result(ac, bg, res);
1811
1812	/*
1813	 * sr_bg_blkno might have been changed by
1814	 * ocfs2_bg_discontig_fix_result
1815	 */
1816	res->sr_bg_stable_blkno = group_bh->b_blocknr;
1817
1818	/*
1819	 * Keep track of previous block descriptor read. When
1820	 * we find a target, if we have read more than X
1821	 * number of descriptors, and the target is reasonably
1822	 * empty, relink him to top of his chain.
1823	 *
1824	 * We've read 0 extra blocks and only send one more to
1825	 * the transaction, yet the next guy to search has a
1826	 * much easier time.
1827	 *
1828	 * Do this *after* figuring out how many bits we're taking out
1829	 * of our target group.
1830	 */
1831	if (!ac->ac_disable_chain_relink &&
1832	    (prev_group_bh) &&
1833	    (ocfs2_block_group_reasonably_empty(bg, res->sr_bits))) {
1834		status = ocfs2_relink_block_group(handle, alloc_inode,
1835						  ac->ac_bh, group_bh,
1836						  prev_group_bh, chain);
1837		if (status < 0) {
1838			mlog_errno(status);
1839			goto bail;
1840		}
1841	}
1842
1843	if (ac->ac_find_loc_only)
1844		goto out_loc_only;
1845
1846	status = ocfs2_alloc_dinode_update_counts(alloc_inode, handle,
1847						  ac->ac_bh, res->sr_bits,
1848						  chain);
1849	if (status) {
1850		mlog_errno(status);
1851		goto bail;
1852	}
1853
1854	status = ocfs2_block_group_set_bits(handle,
1855					    alloc_inode,
1856					    bg,
1857					    group_bh,
1858					    res->sr_bit_offset,
1859					    res->sr_bits);
1860	if (status < 0) {
1861		ocfs2_rollback_alloc_dinode_counts(alloc_inode,
1862					ac->ac_bh, res->sr_bits, chain);
1863		mlog_errno(status);
1864		goto bail;
1865	}
1866
1867	trace_ocfs2_search_chain_end(
1868			(unsigned long long)le64_to_cpu(fe->i_blkno),
1869			res->sr_bits);
1870
1871out_loc_only:
1872	*bits_left = le16_to_cpu(bg->bg_free_bits_count);
1873bail:
1874	brelse(group_bh);
1875	brelse(prev_group_bh);
1876
1877	if (status)
1878		mlog_errno(status);
1879	return status;
1880}
1881
1882/* will give out up to bits_wanted contiguous bits. */
1883static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
1884				     handle_t *handle,
1885				     u32 bits_wanted,
1886				     u32 min_bits,
1887				     struct ocfs2_suballoc_result *res)
1888{
1889	int status;
1890	u16 victim, i;
1891	u16 bits_left = 0;
1892	u64 hint = ac->ac_last_group;
1893	struct ocfs2_chain_list *cl;
1894	struct ocfs2_dinode *fe;
1895
1896	BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1897	BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1898	BUG_ON(!ac->ac_bh);
1899
1900	fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1901
1902	/* The bh was validated by the inode read during
1903	 * ocfs2_reserve_suballoc_bits().  Any corruption is a code bug. */
1904	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
1905
1906	if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1907	    le32_to_cpu(fe->id1.bitmap1.i_total)) {
1908		ocfs2_error(ac->ac_inode->i_sb,
1909			    "Chain allocator dinode %llu has %u used "
1910			    "bits but only %u total.",
1911			    (unsigned long long)le64_to_cpu(fe->i_blkno),
1912			    le32_to_cpu(fe->id1.bitmap1.i_used),
1913			    le32_to_cpu(fe->id1.bitmap1.i_total));
1914		status = -EIO;
1915		goto bail;
1916	}
1917
1918	res->sr_bg_blkno = hint;
1919	if (res->sr_bg_blkno) {
1920		/* Attempt to short-circuit the usual search mechanism
1921		 * by jumping straight to the most recently used
1922		 * allocation group. This helps us maintain some
1923		 * contiguousness across allocations. */
1924		status = ocfs2_search_one_group(ac, handle, bits_wanted,
1925						min_bits, res, &bits_left);
1926		if (!status)
1927			goto set_hint;
1928		if (status < 0 && status != -ENOSPC) {
1929			mlog_errno(status);
1930			goto bail;
1931		}
1932	}
1933
1934	cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1935
1936	victim = ocfs2_find_victim_chain(cl);
1937	ac->ac_chain = victim;
1938
1939	status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1940				    res, &bits_left);
1941	if (!status) {
1942		hint = ocfs2_group_from_res(res);
 
 
 
1943		goto set_hint;
1944	}
1945	if (status < 0 && status != -ENOSPC) {
1946		mlog_errno(status);
1947		goto bail;
1948	}
1949
1950	trace_ocfs2_claim_suballoc_bits(victim);
1951
1952	/* If we didn't pick a good victim, then just default to
1953	 * searching each chain in order. Don't allow chain relinking
1954	 * because we only calculate enough journal credits for one
1955	 * relink per alloc. */
1956	ac->ac_disable_chain_relink = 1;
1957	for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
1958		if (i == victim)
1959			continue;
1960		if (!cl->cl_recs[i].c_free)
1961			continue;
1962
1963		ac->ac_chain = i;
1964		status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1965					    res, &bits_left);
1966		if (!status) {
1967			hint = ocfs2_group_from_res(res);
1968			break;
1969		}
1970		if (status < 0 && status != -ENOSPC) {
1971			mlog_errno(status);
1972			goto bail;
1973		}
1974	}
1975
1976set_hint:
1977	if (status != -ENOSPC) {
1978		/* If the next search of this group is not likely to
1979		 * yield a suitable extent, then we reset the last
1980		 * group hint so as to not waste a disk read */
1981		if (bits_left < min_bits)
1982			ac->ac_last_group = 0;
1983		else
1984			ac->ac_last_group = hint;
1985	}
1986
1987bail:
1988	if (status)
1989		mlog_errno(status);
1990	return status;
1991}
1992
1993int ocfs2_claim_metadata(handle_t *handle,
1994			 struct ocfs2_alloc_context *ac,
1995			 u32 bits_wanted,
1996			 u64 *suballoc_loc,
1997			 u16 *suballoc_bit_start,
1998			 unsigned int *num_bits,
1999			 u64 *blkno_start)
2000{
2001	int status;
2002	struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
2003
2004	BUG_ON(!ac);
2005	BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
2006	BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
2007
2008	status = ocfs2_claim_suballoc_bits(ac,
2009					   handle,
2010					   bits_wanted,
2011					   1,
2012					   &res);
2013	if (status < 0) {
2014		mlog_errno(status);
2015		goto bail;
2016	}
2017	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2018
2019	*suballoc_loc = res.sr_bg_blkno;
2020	*suballoc_bit_start = res.sr_bit_offset;
2021	*blkno_start = res.sr_blkno;
2022	ac->ac_bits_given += res.sr_bits;
2023	*num_bits = res.sr_bits;
2024	status = 0;
2025bail:
2026	if (status)
2027		mlog_errno(status);
2028	return status;
2029}
2030
2031static void ocfs2_init_inode_ac_group(struct inode *dir,
2032				      struct buffer_head *parent_di_bh,
2033				      struct ocfs2_alloc_context *ac)
2034{
2035	struct ocfs2_dinode *di = (struct ocfs2_dinode *)parent_di_bh->b_data;
2036	/*
2037	 * Try to allocate inodes from some specific group.
2038	 *
2039	 * If the parent dir has recorded the last group used in allocation,
2040	 * cool, use it. Otherwise if we try to allocate new inode from the
2041	 * same slot the parent dir belongs to, use the same chunk.
2042	 *
2043	 * We are very careful here to avoid the mistake of setting
2044	 * ac_last_group to a group descriptor from a different (unlocked) slot.
2045	 */
2046	if (OCFS2_I(dir)->ip_last_used_group &&
2047	    OCFS2_I(dir)->ip_last_used_slot == ac->ac_alloc_slot)
2048		ac->ac_last_group = OCFS2_I(dir)->ip_last_used_group;
2049	else if (le16_to_cpu(di->i_suballoc_slot) == ac->ac_alloc_slot) {
2050		if (di->i_suballoc_loc)
2051			ac->ac_last_group = le64_to_cpu(di->i_suballoc_loc);
2052		else
2053			ac->ac_last_group = ocfs2_which_suballoc_group(
2054					le64_to_cpu(di->i_blkno),
2055					le16_to_cpu(di->i_suballoc_bit));
2056	}
2057}
2058
2059static inline void ocfs2_save_inode_ac_group(struct inode *dir,
2060					     struct ocfs2_alloc_context *ac)
2061{
2062	OCFS2_I(dir)->ip_last_used_group = ac->ac_last_group;
2063	OCFS2_I(dir)->ip_last_used_slot = ac->ac_alloc_slot;
2064}
2065
2066int ocfs2_find_new_inode_loc(struct inode *dir,
2067			     struct buffer_head *parent_fe_bh,
2068			     struct ocfs2_alloc_context *ac,
2069			     u64 *fe_blkno)
2070{
2071	int ret;
2072	handle_t *handle = NULL;
2073	struct ocfs2_suballoc_result *res;
2074
2075	BUG_ON(!ac);
2076	BUG_ON(ac->ac_bits_given != 0);
2077	BUG_ON(ac->ac_bits_wanted != 1);
2078	BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2079
2080	res = kzalloc(sizeof(*res), GFP_NOFS);
2081	if (res == NULL) {
2082		ret = -ENOMEM;
2083		mlog_errno(ret);
2084		goto out;
2085	}
2086
2087	ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2088
2089	/*
2090	 * The handle started here is for chain relink. Alternatively,
2091	 * we could just disable relink for these calls.
2092	 */
2093	handle = ocfs2_start_trans(OCFS2_SB(dir->i_sb), OCFS2_SUBALLOC_ALLOC);
2094	if (IS_ERR(handle)) {
2095		ret = PTR_ERR(handle);
2096		handle = NULL;
2097		mlog_errno(ret);
2098		goto out;
2099	}
2100
2101	/*
2102	 * This will instruct ocfs2_claim_suballoc_bits and
2103	 * ocfs2_search_one_group to search but save actual allocation
2104	 * for later.
2105	 */
2106	ac->ac_find_loc_only = 1;
2107
2108	ret = ocfs2_claim_suballoc_bits(ac, handle, 1, 1, res);
2109	if (ret < 0) {
2110		mlog_errno(ret);
2111		goto out;
2112	}
2113
2114	ac->ac_find_loc_priv = res;
2115	*fe_blkno = res->sr_blkno;
2116	ocfs2_update_inode_fsync_trans(handle, dir, 0);
2117out:
2118	if (handle)
2119		ocfs2_commit_trans(OCFS2_SB(dir->i_sb), handle);
2120
2121	if (ret)
2122		kfree(res);
2123
2124	return ret;
2125}
2126
2127int ocfs2_claim_new_inode_at_loc(handle_t *handle,
2128				 struct inode *dir,
2129				 struct ocfs2_alloc_context *ac,
2130				 u64 *suballoc_loc,
2131				 u16 *suballoc_bit,
2132				 u64 di_blkno)
2133{
2134	int ret;
2135	u16 chain;
2136	struct ocfs2_suballoc_result *res = ac->ac_find_loc_priv;
2137	struct buffer_head *bg_bh = NULL;
2138	struct ocfs2_group_desc *bg;
2139	struct ocfs2_dinode *di = (struct ocfs2_dinode *) ac->ac_bh->b_data;
2140
2141	/*
2142	 * Since di_blkno is being passed back in, we check for any
2143	 * inconsistencies which may have happened between
2144	 * calls. These are code bugs as di_blkno is not expected to
2145	 * change once returned from ocfs2_find_new_inode_loc()
2146	 */
2147	BUG_ON(res->sr_blkno != di_blkno);
2148
2149	ret = ocfs2_read_group_descriptor(ac->ac_inode, di,
2150					  res->sr_bg_stable_blkno, &bg_bh);
2151	if (ret) {
2152		mlog_errno(ret);
2153		goto out;
2154	}
2155
2156	bg = (struct ocfs2_group_desc *) bg_bh->b_data;
2157	chain = le16_to_cpu(bg->bg_chain);
2158
2159	ret = ocfs2_alloc_dinode_update_counts(ac->ac_inode, handle,
2160					       ac->ac_bh, res->sr_bits,
2161					       chain);
2162	if (ret) {
2163		mlog_errno(ret);
2164		goto out;
2165	}
2166
2167	ret = ocfs2_block_group_set_bits(handle,
2168					 ac->ac_inode,
2169					 bg,
2170					 bg_bh,
2171					 res->sr_bit_offset,
2172					 res->sr_bits);
2173	if (ret < 0) {
2174		ocfs2_rollback_alloc_dinode_counts(ac->ac_inode,
2175					       ac->ac_bh, res->sr_bits, chain);
2176		mlog_errno(ret);
2177		goto out;
2178	}
2179
2180	trace_ocfs2_claim_new_inode_at_loc((unsigned long long)di_blkno,
2181					   res->sr_bits);
2182
2183	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2184
2185	BUG_ON(res->sr_bits != 1);
2186
2187	*suballoc_loc = res->sr_bg_blkno;
2188	*suballoc_bit = res->sr_bit_offset;
2189	ac->ac_bits_given++;
2190	ocfs2_save_inode_ac_group(dir, ac);
2191
2192out:
2193	brelse(bg_bh);
2194
2195	return ret;
2196}
2197
2198int ocfs2_claim_new_inode(handle_t *handle,
2199			  struct inode *dir,
2200			  struct buffer_head *parent_fe_bh,
2201			  struct ocfs2_alloc_context *ac,
2202			  u64 *suballoc_loc,
2203			  u16 *suballoc_bit,
2204			  u64 *fe_blkno)
2205{
2206	int status;
2207	struct ocfs2_suballoc_result res;
2208
2209	BUG_ON(!ac);
2210	BUG_ON(ac->ac_bits_given != 0);
2211	BUG_ON(ac->ac_bits_wanted != 1);
2212	BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2213
2214	ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2215
2216	status = ocfs2_claim_suballoc_bits(ac,
2217					   handle,
2218					   1,
2219					   1,
2220					   &res);
2221	if (status < 0) {
2222		mlog_errno(status);
2223		goto bail;
2224	}
2225	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2226
2227	BUG_ON(res.sr_bits != 1);
2228
2229	*suballoc_loc = res.sr_bg_blkno;
2230	*suballoc_bit = res.sr_bit_offset;
2231	*fe_blkno = res.sr_blkno;
2232	ac->ac_bits_given++;
2233	ocfs2_save_inode_ac_group(dir, ac);
2234	status = 0;
2235bail:
2236	if (status)
2237		mlog_errno(status);
2238	return status;
2239}
2240
2241/* translate a group desc. blkno and it's bitmap offset into
2242 * disk cluster offset. */
2243static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
2244						   u64 bg_blkno,
2245						   u16 bg_bit_off)
2246{
2247	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2248	u32 cluster = 0;
2249
2250	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2251
2252	if (bg_blkno != osb->first_cluster_group_blkno)
2253		cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
2254	cluster += (u32) bg_bit_off;
2255	return cluster;
2256}
2257
2258/* given a cluster offset, calculate which block group it belongs to
2259 * and return that block offset. */
2260u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster)
2261{
2262	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2263	u32 group_no;
2264
2265	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2266
2267	group_no = cluster / osb->bitmap_cpg;
2268	if (!group_no)
2269		return osb->first_cluster_group_blkno;
2270	return ocfs2_clusters_to_blocks(inode->i_sb,
2271					group_no * osb->bitmap_cpg);
2272}
2273
2274/* given the block number of a cluster start, calculate which cluster
2275 * group and descriptor bitmap offset that corresponds to. */
2276static inline void ocfs2_block_to_cluster_group(struct inode *inode,
2277						u64 data_blkno,
2278						u64 *bg_blkno,
2279						u16 *bg_bit_off)
2280{
2281	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2282	u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
2283
2284	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2285
2286	*bg_blkno = ocfs2_which_cluster_group(inode,
2287					      data_cluster);
2288
2289	if (*bg_blkno == osb->first_cluster_group_blkno)
2290		*bg_bit_off = (u16) data_cluster;
2291	else
2292		*bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
2293							     data_blkno - *bg_blkno);
2294}
2295
2296/*
2297 * min_bits - minimum contiguous chunk from this total allocation we
2298 * can handle. set to what we asked for originally for a full
2299 * contig. allocation, set to '1' to indicate we can deal with extents
2300 * of any size.
2301 */
2302int __ocfs2_claim_clusters(handle_t *handle,
2303			   struct ocfs2_alloc_context *ac,
2304			   u32 min_clusters,
2305			   u32 max_clusters,
2306			   u32 *cluster_start,
2307			   u32 *num_clusters)
2308{
2309	int status;
2310	unsigned int bits_wanted = max_clusters;
2311	struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
2312	struct ocfs2_super *osb = OCFS2_SB(ac->ac_inode->i_sb);
2313
2314	BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
2315
2316	BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
2317	       && ac->ac_which != OCFS2_AC_USE_MAIN);
2318
2319	if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
2320		WARN_ON(min_clusters > 1);
2321
2322		status = ocfs2_claim_local_alloc_bits(osb,
2323						      handle,
2324						      ac,
2325						      bits_wanted,
2326						      cluster_start,
2327						      num_clusters);
2328		if (!status)
2329			atomic_inc(&osb->alloc_stats.local_data);
2330	} else {
2331		if (min_clusters > (osb->bitmap_cpg - 1)) {
2332			/* The only paths asking for contiguousness
2333			 * should know about this already. */
2334			mlog(ML_ERROR, "minimum allocation requested %u exceeds "
2335			     "group bitmap size %u!\n", min_clusters,
2336			     osb->bitmap_cpg);
2337			status = -ENOSPC;
2338			goto bail;
2339		}
2340		/* clamp the current request down to a realistic size. */
2341		if (bits_wanted > (osb->bitmap_cpg - 1))
2342			bits_wanted = osb->bitmap_cpg - 1;
2343
2344		status = ocfs2_claim_suballoc_bits(ac,
2345						   handle,
2346						   bits_wanted,
2347						   min_clusters,
2348						   &res);
2349		if (!status) {
2350			BUG_ON(res.sr_blkno); /* cluster alloc can't set */
2351			*cluster_start =
2352				ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
2353								 res.sr_bg_blkno,
2354								 res.sr_bit_offset);
2355			atomic_inc(&osb->alloc_stats.bitmap_data);
2356			*num_clusters = res.sr_bits;
2357		}
2358	}
2359	if (status < 0) {
2360		if (status != -ENOSPC)
2361			mlog_errno(status);
2362		goto bail;
2363	}
2364
2365	ac->ac_bits_given += *num_clusters;
2366
2367bail:
2368	if (status)
2369		mlog_errno(status);
2370	return status;
2371}
2372
2373int ocfs2_claim_clusters(handle_t *handle,
2374			 struct ocfs2_alloc_context *ac,
2375			 u32 min_clusters,
2376			 u32 *cluster_start,
2377			 u32 *num_clusters)
2378{
2379	unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
2380
2381	return __ocfs2_claim_clusters(handle, ac, min_clusters,
2382				      bits_wanted, cluster_start, num_clusters);
2383}
2384
2385static int ocfs2_block_group_clear_bits(handle_t *handle,
2386					struct inode *alloc_inode,
2387					struct ocfs2_group_desc *bg,
2388					struct buffer_head *group_bh,
2389					unsigned int bit_off,
2390					unsigned int num_bits,
2391					void (*undo_fn)(unsigned int bit,
2392							unsigned long *bmap))
2393{
2394	int status;
2395	unsigned int tmp;
2396	struct ocfs2_group_desc *undo_bg = NULL;
2397
2398	/* The caller got this descriptor from
2399	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
2400	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
2401
2402	trace_ocfs2_block_group_clear_bits(bit_off, num_bits);
2403
2404	BUG_ON(undo_fn && !ocfs2_is_cluster_bitmap(alloc_inode));
2405	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
2406					 group_bh,
2407					 undo_fn ?
2408					 OCFS2_JOURNAL_ACCESS_UNDO :
2409					 OCFS2_JOURNAL_ACCESS_WRITE);
2410	if (status < 0) {
2411		mlog_errno(status);
2412		goto bail;
2413	}
2414
2415	if (undo_fn) {
2416		jbd_lock_bh_state(group_bh);
2417		undo_bg = (struct ocfs2_group_desc *)
2418					bh2jh(group_bh)->b_committed_data;
2419		BUG_ON(!undo_bg);
2420	}
2421
2422	tmp = num_bits;
2423	while(tmp--) {
2424		ocfs2_clear_bit((bit_off + tmp),
2425				(unsigned long *) bg->bg_bitmap);
2426		if (undo_fn)
2427			undo_fn(bit_off + tmp,
2428				(unsigned long *) undo_bg->bg_bitmap);
2429	}
2430	le16_add_cpu(&bg->bg_free_bits_count, num_bits);
2431	if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
2432		ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit"
2433			    " count %u but claims %u are freed. num_bits %d",
2434			    (unsigned long long)le64_to_cpu(bg->bg_blkno),
2435			    le16_to_cpu(bg->bg_bits),
2436			    le16_to_cpu(bg->bg_free_bits_count), num_bits);
2437		return -EROFS;
 
2438	}
2439
2440	if (undo_fn)
2441		jbd_unlock_bh_state(group_bh);
2442
2443	ocfs2_journal_dirty(handle, group_bh);
2444bail:
2445	return status;
2446}
2447
2448/*
2449 * expects the suballoc inode to already be locked.
2450 */
2451static int _ocfs2_free_suballoc_bits(handle_t *handle,
2452				     struct inode *alloc_inode,
2453				     struct buffer_head *alloc_bh,
2454				     unsigned int start_bit,
2455				     u64 bg_blkno,
2456				     unsigned int count,
2457				     void (*undo_fn)(unsigned int bit,
2458						     unsigned long *bitmap))
2459{
2460	int status = 0;
2461	u32 tmp_used;
2462	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
2463	struct ocfs2_chain_list *cl = &fe->id2.i_chain;
2464	struct buffer_head *group_bh = NULL;
2465	struct ocfs2_group_desc *group;
2466
2467	/* The alloc_bh comes from ocfs2_free_dinode() or
2468	 * ocfs2_free_clusters().  The callers have all locked the
2469	 * allocator and gotten alloc_bh from the lock call.  This
2470	 * validates the dinode buffer.  Any corruption that has happened
2471	 * is a code bug. */
2472	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
2473	BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
2474
2475	trace_ocfs2_free_suballoc_bits(
2476		(unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
2477		(unsigned long long)bg_blkno,
2478		start_bit, count);
2479
2480	status = ocfs2_read_group_descriptor(alloc_inode, fe, bg_blkno,
2481					     &group_bh);
2482	if (status < 0) {
2483		mlog_errno(status);
2484		goto bail;
2485	}
2486	group = (struct ocfs2_group_desc *) group_bh->b_data;
2487
2488	BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
2489
2490	status = ocfs2_block_group_clear_bits(handle, alloc_inode,
2491					      group, group_bh,
2492					      start_bit, count, undo_fn);
2493	if (status < 0) {
2494		mlog_errno(status);
2495		goto bail;
2496	}
2497
2498	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
2499					 alloc_bh, OCFS2_JOURNAL_ACCESS_WRITE);
2500	if (status < 0) {
2501		mlog_errno(status);
 
 
2502		goto bail;
2503	}
2504
2505	le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
2506		     count);
2507	tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
2508	fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
2509	ocfs2_journal_dirty(handle, alloc_bh);
2510
2511bail:
2512	brelse(group_bh);
2513
2514	if (status)
2515		mlog_errno(status);
2516	return status;
2517}
2518
2519int ocfs2_free_suballoc_bits(handle_t *handle,
2520			     struct inode *alloc_inode,
2521			     struct buffer_head *alloc_bh,
2522			     unsigned int start_bit,
2523			     u64 bg_blkno,
2524			     unsigned int count)
2525{
2526	return _ocfs2_free_suballoc_bits(handle, alloc_inode, alloc_bh,
2527					 start_bit, bg_blkno, count, NULL);
2528}
2529
2530int ocfs2_free_dinode(handle_t *handle,
2531		      struct inode *inode_alloc_inode,
2532		      struct buffer_head *inode_alloc_bh,
2533		      struct ocfs2_dinode *di)
2534{
2535	u64 blk = le64_to_cpu(di->i_blkno);
2536	u16 bit = le16_to_cpu(di->i_suballoc_bit);
2537	u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
2538
2539	if (di->i_suballoc_loc)
2540		bg_blkno = le64_to_cpu(di->i_suballoc_loc);
2541	return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
2542					inode_alloc_bh, bit, bg_blkno, 1);
2543}
2544
2545static int _ocfs2_free_clusters(handle_t *handle,
2546				struct inode *bitmap_inode,
2547				struct buffer_head *bitmap_bh,
2548				u64 start_blk,
2549				unsigned int num_clusters,
2550				void (*undo_fn)(unsigned int bit,
2551						unsigned long *bitmap))
2552{
2553	int status;
2554	u16 bg_start_bit;
2555	u64 bg_blkno;
2556	struct ocfs2_dinode *fe;
2557
2558	/* You can't ever have a contiguous set of clusters
2559	 * bigger than a block group bitmap so we never have to worry
2560	 * about looping on them.
2561	 * This is expensive. We can safely remove once this stuff has
2562	 * gotten tested really well. */
2563	BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb, ocfs2_blocks_to_clusters(bitmap_inode->i_sb, start_blk)));
 
 
2564
2565	fe = (struct ocfs2_dinode *) bitmap_bh->b_data;
2566
2567	ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
2568				     &bg_start_bit);
2569
2570	trace_ocfs2_free_clusters((unsigned long long)bg_blkno,
2571			(unsigned long long)start_blk,
2572			bg_start_bit, num_clusters);
2573
2574	status = _ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
2575					   bg_start_bit, bg_blkno,
2576					   num_clusters, undo_fn);
2577	if (status < 0) {
2578		mlog_errno(status);
2579		goto out;
2580	}
2581
2582	ocfs2_local_alloc_seen_free_bits(OCFS2_SB(bitmap_inode->i_sb),
2583					 num_clusters);
2584
2585out:
2586	if (status)
2587		mlog_errno(status);
2588	return status;
2589}
2590
2591int ocfs2_free_clusters(handle_t *handle,
2592			struct inode *bitmap_inode,
2593			struct buffer_head *bitmap_bh,
2594			u64 start_blk,
2595			unsigned int num_clusters)
2596{
2597	return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2598				    start_blk, num_clusters,
2599				    _ocfs2_set_bit);
2600}
2601
2602/*
2603 * Give never-used clusters back to the global bitmap.  We don't need
2604 * to protect these bits in the undo buffer.
2605 */
2606int ocfs2_release_clusters(handle_t *handle,
2607			   struct inode *bitmap_inode,
2608			   struct buffer_head *bitmap_bh,
2609			   u64 start_blk,
2610			   unsigned int num_clusters)
2611{
2612	return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2613				    start_blk, num_clusters,
2614				    _ocfs2_clear_bit);
2615}
2616
2617static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg)
2618{
2619	printk("Block Group:\n");
2620	printk("bg_signature:       %s\n", bg->bg_signature);
2621	printk("bg_size:            %u\n", bg->bg_size);
2622	printk("bg_bits:            %u\n", bg->bg_bits);
2623	printk("bg_free_bits_count: %u\n", bg->bg_free_bits_count);
2624	printk("bg_chain:           %u\n", bg->bg_chain);
2625	printk("bg_generation:      %u\n", le32_to_cpu(bg->bg_generation));
2626	printk("bg_next_group:      %llu\n",
2627	       (unsigned long long)bg->bg_next_group);
2628	printk("bg_parent_dinode:   %llu\n",
2629	       (unsigned long long)bg->bg_parent_dinode);
2630	printk("bg_blkno:           %llu\n",
2631	       (unsigned long long)bg->bg_blkno);
2632}
2633
2634static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe)
2635{
2636	int i;
2637
2638	printk("Suballoc Inode %llu:\n", (unsigned long long)fe->i_blkno);
2639	printk("i_signature:                  %s\n", fe->i_signature);
2640	printk("i_size:                       %llu\n",
2641	       (unsigned long long)fe->i_size);
2642	printk("i_clusters:                   %u\n", fe->i_clusters);
2643	printk("i_generation:                 %u\n",
2644	       le32_to_cpu(fe->i_generation));
2645	printk("id1.bitmap1.i_used:           %u\n",
2646	       le32_to_cpu(fe->id1.bitmap1.i_used));
2647	printk("id1.bitmap1.i_total:          %u\n",
2648	       le32_to_cpu(fe->id1.bitmap1.i_total));
2649	printk("id2.i_chain.cl_cpg:           %u\n", fe->id2.i_chain.cl_cpg);
2650	printk("id2.i_chain.cl_bpc:           %u\n", fe->id2.i_chain.cl_bpc);
2651	printk("id2.i_chain.cl_count:         %u\n", fe->id2.i_chain.cl_count);
2652	printk("id2.i_chain.cl_next_free_rec: %u\n",
2653	       fe->id2.i_chain.cl_next_free_rec);
2654	for(i = 0; i < fe->id2.i_chain.cl_next_free_rec; i++) {
2655		printk("fe->id2.i_chain.cl_recs[%d].c_free:  %u\n", i,
2656		       fe->id2.i_chain.cl_recs[i].c_free);
2657		printk("fe->id2.i_chain.cl_recs[%d].c_total: %u\n", i,
2658		       fe->id2.i_chain.cl_recs[i].c_total);
2659		printk("fe->id2.i_chain.cl_recs[%d].c_blkno: %llu\n", i,
2660		       (unsigned long long)fe->id2.i_chain.cl_recs[i].c_blkno);
2661	}
2662}
2663
2664/*
2665 * For a given allocation, determine which allocators will need to be
2666 * accessed, and lock them, reserving the appropriate number of bits.
2667 *
2668 * Sparse file systems call this from ocfs2_write_begin_nolock()
2669 * and ocfs2_allocate_unwritten_extents().
2670 *
2671 * File systems which don't support holes call this from
2672 * ocfs2_extend_allocation().
2673 */
2674int ocfs2_lock_allocators(struct inode *inode,
2675			  struct ocfs2_extent_tree *et,
2676			  u32 clusters_to_add, u32 extents_to_split,
2677			  struct ocfs2_alloc_context **data_ac,
2678			  struct ocfs2_alloc_context **meta_ac)
2679{
2680	int ret = 0, num_free_extents;
2681	unsigned int max_recs_needed = clusters_to_add + 2 * extents_to_split;
2682	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2683
2684	*meta_ac = NULL;
2685	if (data_ac)
2686		*data_ac = NULL;
2687
2688	BUG_ON(clusters_to_add != 0 && data_ac == NULL);
2689
2690	num_free_extents = ocfs2_num_free_extents(osb, et);
2691	if (num_free_extents < 0) {
2692		ret = num_free_extents;
2693		mlog_errno(ret);
2694		goto out;
2695	}
2696
2697	/*
2698	 * Sparse allocation file systems need to be more conservative
2699	 * with reserving room for expansion - the actual allocation
2700	 * happens while we've got a journal handle open so re-taking
2701	 * a cluster lock (because we ran out of room for another
2702	 * extent) will violate ordering rules.
2703	 *
2704	 * Most of the time we'll only be seeing this 1 cluster at a time
2705	 * anyway.
2706	 *
2707	 * Always lock for any unwritten extents - we might want to
2708	 * add blocks during a split.
2709	 */
2710	if (!num_free_extents ||
2711	    (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed)) {
2712		ret = ocfs2_reserve_new_metadata(osb, et->et_root_el, meta_ac);
2713		if (ret < 0) {
2714			if (ret != -ENOSPC)
2715				mlog_errno(ret);
2716			goto out;
2717		}
2718	}
2719
2720	if (clusters_to_add == 0)
2721		goto out;
2722
2723	ret = ocfs2_reserve_clusters(osb, clusters_to_add, data_ac);
2724	if (ret < 0) {
2725		if (ret != -ENOSPC)
2726			mlog_errno(ret);
2727		goto out;
2728	}
2729
2730out:
2731	if (ret) {
2732		if (*meta_ac) {
2733			ocfs2_free_alloc_context(*meta_ac);
2734			*meta_ac = NULL;
2735		}
2736
2737		/*
2738		 * We cannot have an error and a non null *data_ac.
2739		 */
2740	}
2741
2742	return ret;
2743}
2744
2745/*
2746 * Read the inode specified by blkno to get suballoc_slot and
2747 * suballoc_bit.
2748 */
2749static int ocfs2_get_suballoc_slot_bit(struct ocfs2_super *osb, u64 blkno,
2750				       u16 *suballoc_slot, u64 *group_blkno,
2751				       u16 *suballoc_bit)
2752{
2753	int status;
2754	struct buffer_head *inode_bh = NULL;
2755	struct ocfs2_dinode *inode_fe;
2756
2757	trace_ocfs2_get_suballoc_slot_bit((unsigned long long)blkno);
2758
2759	/* dirty read disk */
2760	status = ocfs2_read_blocks_sync(osb, blkno, 1, &inode_bh);
2761	if (status < 0) {
2762		mlog(ML_ERROR, "read block %llu failed %d\n",
2763		     (unsigned long long)blkno, status);
2764		goto bail;
2765	}
2766
2767	inode_fe = (struct ocfs2_dinode *) inode_bh->b_data;
2768	if (!OCFS2_IS_VALID_DINODE(inode_fe)) {
2769		mlog(ML_ERROR, "invalid inode %llu requested\n",
2770		     (unsigned long long)blkno);
2771		status = -EINVAL;
2772		goto bail;
2773	}
2774
2775	if (le16_to_cpu(inode_fe->i_suballoc_slot) != (u16)OCFS2_INVALID_SLOT &&
2776	    (u32)le16_to_cpu(inode_fe->i_suballoc_slot) > osb->max_slots - 1) {
2777		mlog(ML_ERROR, "inode %llu has invalid suballoc slot %u\n",
2778		     (unsigned long long)blkno,
2779		     (u32)le16_to_cpu(inode_fe->i_suballoc_slot));
2780		status = -EINVAL;
2781		goto bail;
2782	}
2783
2784	if (suballoc_slot)
2785		*suballoc_slot = le16_to_cpu(inode_fe->i_suballoc_slot);
2786	if (suballoc_bit)
2787		*suballoc_bit = le16_to_cpu(inode_fe->i_suballoc_bit);
2788	if (group_blkno)
2789		*group_blkno = le64_to_cpu(inode_fe->i_suballoc_loc);
2790
2791bail:
2792	brelse(inode_bh);
2793
2794	if (status)
2795		mlog_errno(status);
2796	return status;
2797}
2798
2799/*
2800 * test whether bit is SET in allocator bitmap or not.  on success, 0
2801 * is returned and *res is 1 for SET; 0 otherwise.  when fails, errno
2802 * is returned and *res is meaningless.  Call this after you have
2803 * cluster locked against suballoc, or you may get a result based on
2804 * non-up2date contents
2805 */
2806static int ocfs2_test_suballoc_bit(struct ocfs2_super *osb,
2807				   struct inode *suballoc,
2808				   struct buffer_head *alloc_bh,
2809				   u64 group_blkno, u64 blkno,
2810				   u16 bit, int *res)
2811{
2812	struct ocfs2_dinode *alloc_di;
2813	struct ocfs2_group_desc *group;
2814	struct buffer_head *group_bh = NULL;
2815	u64 bg_blkno;
2816	int status;
2817
2818	trace_ocfs2_test_suballoc_bit((unsigned long long)blkno,
2819				      (unsigned int)bit);
2820
2821	alloc_di = (struct ocfs2_dinode *)alloc_bh->b_data;
2822	if ((bit + 1) > ocfs2_bits_per_group(&alloc_di->id2.i_chain)) {
2823		mlog(ML_ERROR, "suballoc bit %u out of range of %u\n",
2824		     (unsigned int)bit,
2825		     ocfs2_bits_per_group(&alloc_di->id2.i_chain));
2826		status = -EINVAL;
2827		goto bail;
2828	}
2829
2830	bg_blkno = group_blkno ? group_blkno :
2831		   ocfs2_which_suballoc_group(blkno, bit);
2832	status = ocfs2_read_group_descriptor(suballoc, alloc_di, bg_blkno,
2833					     &group_bh);
2834	if (status < 0) {
2835		mlog(ML_ERROR, "read group %llu failed %d\n",
2836		     (unsigned long long)bg_blkno, status);
2837		goto bail;
2838	}
2839
2840	group = (struct ocfs2_group_desc *) group_bh->b_data;
2841	*res = ocfs2_test_bit(bit, (unsigned long *)group->bg_bitmap);
2842
2843bail:
2844	brelse(group_bh);
2845
2846	if (status)
2847		mlog_errno(status);
2848	return status;
2849}
2850
2851/*
2852 * Test if the bit representing this inode (blkno) is set in the
2853 * suballocator.
2854 *
2855 * On success, 0 is returned and *res is 1 for SET; 0 otherwise.
2856 *
2857 * In the event of failure, a negative value is returned and *res is
2858 * meaningless.
2859 *
2860 * Callers must make sure to hold nfs_sync_lock to prevent
2861 * ocfs2_delete_inode() on another node from accessing the same
2862 * suballocator concurrently.
2863 */
2864int ocfs2_test_inode_bit(struct ocfs2_super *osb, u64 blkno, int *res)
2865{
2866	int status;
2867	u64 group_blkno = 0;
2868	u16 suballoc_bit = 0, suballoc_slot = 0;
2869	struct inode *inode_alloc_inode;
2870	struct buffer_head *alloc_bh = NULL;
2871
2872	trace_ocfs2_test_inode_bit((unsigned long long)blkno);
2873
2874	status = ocfs2_get_suballoc_slot_bit(osb, blkno, &suballoc_slot,
2875					     &group_blkno, &suballoc_bit);
2876	if (status < 0) {
2877		mlog(ML_ERROR, "get alloc slot and bit failed %d\n", status);
2878		goto bail;
2879	}
2880
2881	inode_alloc_inode =
2882		ocfs2_get_system_file_inode(osb, INODE_ALLOC_SYSTEM_INODE,
2883					    suballoc_slot);
2884	if (!inode_alloc_inode) {
2885		/* the error code could be inaccurate, but we are not able to
2886		 * get the correct one. */
2887		status = -EINVAL;
2888		mlog(ML_ERROR, "unable to get alloc inode in slot %u\n",
2889		     (u32)suballoc_slot);
2890		goto bail;
2891	}
2892
2893	mutex_lock(&inode_alloc_inode->i_mutex);
2894	status = ocfs2_inode_lock(inode_alloc_inode, &alloc_bh, 0);
2895	if (status < 0) {
2896		mutex_unlock(&inode_alloc_inode->i_mutex);
2897		iput(inode_alloc_inode);
2898		mlog(ML_ERROR, "lock on alloc inode on slot %u failed %d\n",
2899		     (u32)suballoc_slot, status);
2900		goto bail;
2901	}
2902
2903	status = ocfs2_test_suballoc_bit(osb, inode_alloc_inode, alloc_bh,
2904					 group_blkno, blkno, suballoc_bit, res);
2905	if (status < 0)
2906		mlog(ML_ERROR, "test suballoc bit failed %d\n", status);
2907
2908	ocfs2_inode_unlock(inode_alloc_inode, 0);
2909	mutex_unlock(&inode_alloc_inode->i_mutex);
2910
2911	iput(inode_alloc_inode);
2912	brelse(alloc_bh);
2913bail:
2914	if (status)
2915		mlog_errno(status);
2916	return status;
2917}