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v6.9.4
   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
 
   3 * suballoc.c
   4 *
   5 * metadata alloc and free
   6 * Inspired by ext3 block groups.
   7 *
   8 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
   9 */
  10
  11#include <linux/fs.h>
  12#include <linux/types.h>
  13#include <linux/slab.h>
  14#include <linux/highmem.h>
  15
  16#include <cluster/masklog.h>
  17
  18#include "ocfs2.h"
  19
  20#include "alloc.h"
  21#include "blockcheck.h"
  22#include "dlmglue.h"
  23#include "inode.h"
  24#include "journal.h"
  25#include "localalloc.h"
  26#include "suballoc.h"
  27#include "super.h"
  28#include "sysfile.h"
  29#include "uptodate.h"
  30#include "ocfs2_trace.h"
  31
  32#include "buffer_head_io.h"
  33
  34#define NOT_ALLOC_NEW_GROUP		0
  35#define ALLOC_NEW_GROUP			0x1
  36#define ALLOC_GROUPS_FROM_GLOBAL	0x2
  37
  38#define OCFS2_MAX_TO_STEAL		1024
  39
  40struct ocfs2_suballoc_result {
  41	u64		sr_bg_blkno;	/* The bg we allocated from.  Set
  42					   to 0 when a block group is
  43					   contiguous. */
  44	u64		sr_bg_stable_blkno; /*
  45					     * Doesn't change, always
  46					     * set to target block
  47					     * group descriptor
  48					     * block.
  49					     */
  50	u64		sr_blkno;	/* The first allocated block */
  51	unsigned int	sr_bit_offset;	/* The bit in the bg */
  52	unsigned int	sr_bits;	/* How many bits we claimed */
  53};
  54
  55static u64 ocfs2_group_from_res(struct ocfs2_suballoc_result *res)
  56{
  57	if (res->sr_blkno == 0)
  58		return 0;
  59
  60	if (res->sr_bg_blkno)
  61		return res->sr_bg_blkno;
  62
  63	return ocfs2_which_suballoc_group(res->sr_blkno, res->sr_bit_offset);
  64}
  65
 
 
  66static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl);
  67static int ocfs2_block_group_fill(handle_t *handle,
  68				  struct inode *alloc_inode,
  69				  struct buffer_head *bg_bh,
  70				  u64 group_blkno,
  71				  unsigned int group_clusters,
  72				  u16 my_chain,
  73				  struct ocfs2_chain_list *cl);
  74static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
  75				   struct inode *alloc_inode,
  76				   struct buffer_head *bh,
  77				   u64 max_block,
  78				   u64 *last_alloc_group,
  79				   int flags);
  80
  81static int ocfs2_cluster_group_search(struct inode *inode,
  82				      struct buffer_head *group_bh,
  83				      u32 bits_wanted, u32 min_bits,
  84				      u64 max_block,
  85				      struct ocfs2_suballoc_result *res);
  86static int ocfs2_block_group_search(struct inode *inode,
  87				    struct buffer_head *group_bh,
  88				    u32 bits_wanted, u32 min_bits,
  89				    u64 max_block,
  90				    struct ocfs2_suballoc_result *res);
  91static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
  92				     handle_t *handle,
  93				     u32 bits_wanted,
  94				     u32 min_bits,
  95				     struct ocfs2_suballoc_result *res);
  96static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
  97					 int nr);
  98static int ocfs2_relink_block_group(handle_t *handle,
  99				    struct inode *alloc_inode,
 100				    struct buffer_head *fe_bh,
 101				    struct buffer_head *bg_bh,
 102				    struct buffer_head *prev_bg_bh,
 103				    u16 chain);
 104static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
 105						     u32 wanted);
 106static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
 107						   u64 bg_blkno,
 108						   u16 bg_bit_off);
 109static inline void ocfs2_block_to_cluster_group(struct inode *inode,
 110						u64 data_blkno,
 111						u64 *bg_blkno,
 112						u16 *bg_bit_off);
 113static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
 114					     u32 bits_wanted, u64 max_block,
 115					     int flags,
 116					     struct ocfs2_alloc_context **ac);
 117
 118void ocfs2_free_ac_resource(struct ocfs2_alloc_context *ac)
 119{
 120	struct inode *inode = ac->ac_inode;
 121
 122	if (inode) {
 123		if (ac->ac_which != OCFS2_AC_USE_LOCAL)
 124			ocfs2_inode_unlock(inode, 1);
 125
 126		inode_unlock(inode);
 127
 128		iput(inode);
 129		ac->ac_inode = NULL;
 130	}
 131	brelse(ac->ac_bh);
 132	ac->ac_bh = NULL;
 133	ac->ac_resv = NULL;
 134	kfree(ac->ac_find_loc_priv);
 135	ac->ac_find_loc_priv = NULL;
 136}
 137
 138void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
 139{
 140	ocfs2_free_ac_resource(ac);
 141	kfree(ac);
 142}
 143
 144static u32 ocfs2_bits_per_group(struct ocfs2_chain_list *cl)
 145{
 146	return (u32)le16_to_cpu(cl->cl_cpg) * (u32)le16_to_cpu(cl->cl_bpc);
 147}
 148
 149#define do_error(fmt, ...)						\
 150do {									\
 151	if (resize)							\
 152		mlog(ML_ERROR, fmt, ##__VA_ARGS__);			\
 153	else								\
 154		return ocfs2_error(sb, fmt, ##__VA_ARGS__);		\
 155} while (0)
 156
 157static int ocfs2_validate_gd_self(struct super_block *sb,
 158				  struct buffer_head *bh,
 159				  int resize)
 160{
 161	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 162
 163	if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
 164		do_error("Group descriptor #%llu has bad signature %.*s\n",
 165			 (unsigned long long)bh->b_blocknr, 7,
 166			 gd->bg_signature);
 167	}
 168
 169	if (le64_to_cpu(gd->bg_blkno) != bh->b_blocknr) {
 170		do_error("Group descriptor #%llu has an invalid bg_blkno of %llu\n",
 171			 (unsigned long long)bh->b_blocknr,
 172			 (unsigned long long)le64_to_cpu(gd->bg_blkno));
 173	}
 174
 175	if (le32_to_cpu(gd->bg_generation) != OCFS2_SB(sb)->fs_generation) {
 176		do_error("Group descriptor #%llu has an invalid fs_generation of #%u\n",
 177			 (unsigned long long)bh->b_blocknr,
 178			 le32_to_cpu(gd->bg_generation));
 179	}
 180
 181	if (le16_to_cpu(gd->bg_free_bits_count) > le16_to_cpu(gd->bg_bits)) {
 182		do_error("Group descriptor #%llu has bit count %u but claims that %u are free\n",
 183			 (unsigned long long)bh->b_blocknr,
 184			 le16_to_cpu(gd->bg_bits),
 185			 le16_to_cpu(gd->bg_free_bits_count));
 186	}
 187
 188	if (le16_to_cpu(gd->bg_bits) > (8 * le16_to_cpu(gd->bg_size))) {
 189		do_error("Group descriptor #%llu has bit count %u but max bitmap bits of %u\n",
 190			 (unsigned long long)bh->b_blocknr,
 191			 le16_to_cpu(gd->bg_bits),
 192			 8 * le16_to_cpu(gd->bg_size));
 193	}
 194
 195	return 0;
 196}
 197
 198static int ocfs2_validate_gd_parent(struct super_block *sb,
 199				    struct ocfs2_dinode *di,
 200				    struct buffer_head *bh,
 201				    int resize)
 202{
 203	unsigned int max_bits;
 204	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 205
 206	if (di->i_blkno != gd->bg_parent_dinode) {
 207		do_error("Group descriptor #%llu has bad parent pointer (%llu, expected %llu)\n",
 208			 (unsigned long long)bh->b_blocknr,
 209			 (unsigned long long)le64_to_cpu(gd->bg_parent_dinode),
 210			 (unsigned long long)le64_to_cpu(di->i_blkno));
 211	}
 212
 213	max_bits = le16_to_cpu(di->id2.i_chain.cl_cpg) * le16_to_cpu(di->id2.i_chain.cl_bpc);
 214	if (le16_to_cpu(gd->bg_bits) > max_bits) {
 215		do_error("Group descriptor #%llu has bit count of %u\n",
 216			 (unsigned long long)bh->b_blocknr,
 217			 le16_to_cpu(gd->bg_bits));
 218	}
 219
 220	/* In resize, we may meet the case bg_chain == cl_next_free_rec. */
 221	if ((le16_to_cpu(gd->bg_chain) >
 222	     le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) ||
 223	    ((le16_to_cpu(gd->bg_chain) ==
 224	     le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) && !resize)) {
 225		do_error("Group descriptor #%llu has bad chain %u\n",
 226			 (unsigned long long)bh->b_blocknr,
 227			 le16_to_cpu(gd->bg_chain));
 228	}
 229
 230	return 0;
 231}
 232
 233#undef do_error
 234
 235/*
 236 * This version only prints errors.  It does not fail the filesystem, and
 237 * exists only for resize.
 238 */
 239int ocfs2_check_group_descriptor(struct super_block *sb,
 240				 struct ocfs2_dinode *di,
 241				 struct buffer_head *bh)
 242{
 243	int rc;
 244	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 245
 246	BUG_ON(!buffer_uptodate(bh));
 247
 248	/*
 249	 * If the ecc fails, we return the error but otherwise
 250	 * leave the filesystem running.  We know any error is
 251	 * local to this block.
 252	 */
 253	rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
 254	if (rc) {
 255		mlog(ML_ERROR,
 256		     "Checksum failed for group descriptor %llu\n",
 257		     (unsigned long long)bh->b_blocknr);
 258	} else
 259		rc = ocfs2_validate_gd_self(sb, bh, 1);
 260	if (!rc)
 261		rc = ocfs2_validate_gd_parent(sb, di, bh, 1);
 262
 263	return rc;
 264}
 265
 266static int ocfs2_validate_group_descriptor(struct super_block *sb,
 267					   struct buffer_head *bh)
 268{
 269	int rc;
 270	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 271
 272	trace_ocfs2_validate_group_descriptor(
 273					(unsigned long long)bh->b_blocknr);
 274
 275	BUG_ON(!buffer_uptodate(bh));
 276
 277	/*
 278	 * If the ecc fails, we return the error but otherwise
 279	 * leave the filesystem running.  We know any error is
 280	 * local to this block.
 281	 */
 282	rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
 283	if (rc)
 284		return rc;
 285
 286	/*
 287	 * Errors after here are fatal.
 288	 */
 289
 290	return ocfs2_validate_gd_self(sb, bh, 0);
 291}
 292
 293int ocfs2_read_group_descriptor(struct inode *inode, struct ocfs2_dinode *di,
 294				u64 gd_blkno, struct buffer_head **bh)
 295{
 296	int rc;
 297	struct buffer_head *tmp = *bh;
 298
 299	rc = ocfs2_read_block(INODE_CACHE(inode), gd_blkno, &tmp,
 300			      ocfs2_validate_group_descriptor);
 301	if (rc)
 302		goto out;
 303
 304	rc = ocfs2_validate_gd_parent(inode->i_sb, di, tmp, 0);
 305	if (rc) {
 306		brelse(tmp);
 307		goto out;
 308	}
 309
 310	/* If ocfs2_read_block() got us a new bh, pass it up. */
 311	if (!*bh)
 312		*bh = tmp;
 313
 314out:
 315	return rc;
 316}
 317
 318static void ocfs2_bg_discontig_add_extent(struct ocfs2_super *osb,
 319					  struct ocfs2_group_desc *bg,
 320					  struct ocfs2_chain_list *cl,
 321					  u64 p_blkno, unsigned int clusters)
 322{
 323	struct ocfs2_extent_list *el = &bg->bg_list;
 324	struct ocfs2_extent_rec *rec;
 325
 326	BUG_ON(!ocfs2_supports_discontig_bg(osb));
 327	if (!el->l_next_free_rec)
 328		el->l_count = cpu_to_le16(ocfs2_extent_recs_per_gd(osb->sb));
 329	rec = &el->l_recs[le16_to_cpu(el->l_next_free_rec)];
 330	rec->e_blkno = cpu_to_le64(p_blkno);
 331	rec->e_cpos = cpu_to_le32(le16_to_cpu(bg->bg_bits) /
 332				  le16_to_cpu(cl->cl_bpc));
 333	rec->e_leaf_clusters = cpu_to_le16(clusters);
 334	le16_add_cpu(&bg->bg_bits, clusters * le16_to_cpu(cl->cl_bpc));
 335	le16_add_cpu(&bg->bg_free_bits_count,
 336		     clusters * le16_to_cpu(cl->cl_bpc));
 337	le16_add_cpu(&el->l_next_free_rec, 1);
 338}
 339
 340static int ocfs2_block_group_fill(handle_t *handle,
 341				  struct inode *alloc_inode,
 342				  struct buffer_head *bg_bh,
 343				  u64 group_blkno,
 344				  unsigned int group_clusters,
 345				  u16 my_chain,
 346				  struct ocfs2_chain_list *cl)
 347{
 348	int status = 0;
 349	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 350	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 351	struct super_block * sb = alloc_inode->i_sb;
 352
 353	if (((unsigned long long) bg_bh->b_blocknr) != group_blkno) {
 354		status = ocfs2_error(alloc_inode->i_sb,
 355				     "group block (%llu) != b_blocknr (%llu)\n",
 356				     (unsigned long long)group_blkno,
 357				     (unsigned long long) bg_bh->b_blocknr);
 358		goto bail;
 359	}
 360
 361	status = ocfs2_journal_access_gd(handle,
 362					 INODE_CACHE(alloc_inode),
 363					 bg_bh,
 364					 OCFS2_JOURNAL_ACCESS_CREATE);
 365	if (status < 0) {
 366		mlog_errno(status);
 367		goto bail;
 368	}
 369
 370	memset(bg, 0, sb->s_blocksize);
 371	strcpy(bg->bg_signature, OCFS2_GROUP_DESC_SIGNATURE);
 372	bg->bg_generation = cpu_to_le32(osb->fs_generation);
 373	bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb, 1,
 374						osb->s_feature_incompat));
 375	bg->bg_chain = cpu_to_le16(my_chain);
 376	bg->bg_next_group = cl->cl_recs[my_chain].c_blkno;
 377	bg->bg_parent_dinode = cpu_to_le64(OCFS2_I(alloc_inode)->ip_blkno);
 378	bg->bg_blkno = cpu_to_le64(group_blkno);
 379	if (group_clusters == le16_to_cpu(cl->cl_cpg))
 380		bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
 381	else
 382		ocfs2_bg_discontig_add_extent(osb, bg, cl, group_blkno,
 383					      group_clusters);
 384
 385	/* set the 1st bit in the bitmap to account for the descriptor block */
 386	ocfs2_set_bit(0, (unsigned long *)bg->bg_bitmap);
 387	bg->bg_free_bits_count = cpu_to_le16(le16_to_cpu(bg->bg_bits) - 1);
 388
 389	ocfs2_journal_dirty(handle, bg_bh);
 390
 391	/* There is no need to zero out or otherwise initialize the
 392	 * other blocks in a group - All valid FS metadata in a block
 393	 * group stores the superblock fs_generation value at
 394	 * allocation time. */
 395
 396bail:
 397	if (status)
 398		mlog_errno(status);
 399	return status;
 400}
 401
 402static inline u16 ocfs2_find_smallest_chain(struct ocfs2_chain_list *cl)
 403{
 404	u16 curr, best;
 405
 406	best = curr = 0;
 407	while (curr < le16_to_cpu(cl->cl_count)) {
 408		if (le32_to_cpu(cl->cl_recs[best].c_total) >
 409		    le32_to_cpu(cl->cl_recs[curr].c_total))
 410			best = curr;
 411		curr++;
 412	}
 413	return best;
 414}
 415
 416static struct buffer_head *
 417ocfs2_block_group_alloc_contig(struct ocfs2_super *osb, handle_t *handle,
 418			       struct inode *alloc_inode,
 419			       struct ocfs2_alloc_context *ac,
 420			       struct ocfs2_chain_list *cl)
 421{
 422	int status;
 423	u32 bit_off, num_bits;
 424	u64 bg_blkno;
 425	struct buffer_head *bg_bh;
 426	unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
 427
 428	status = ocfs2_claim_clusters(handle, ac,
 429				      le16_to_cpu(cl->cl_cpg), &bit_off,
 430				      &num_bits);
 431	if (status < 0) {
 432		if (status != -ENOSPC)
 433			mlog_errno(status);
 434		goto bail;
 435	}
 436
 437	/* setup the group */
 438	bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 439	trace_ocfs2_block_group_alloc_contig(
 440	     (unsigned long long)bg_blkno, alloc_rec);
 441
 442	bg_bh = sb_getblk(osb->sb, bg_blkno);
 443	if (!bg_bh) {
 444		status = -ENOMEM;
 445		mlog_errno(status);
 446		goto bail;
 447	}
 448	ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
 449
 450	status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
 451					bg_blkno, num_bits, alloc_rec, cl);
 452	if (status < 0) {
 453		brelse(bg_bh);
 454		mlog_errno(status);
 455	}
 456
 457bail:
 458	return status ? ERR_PTR(status) : bg_bh;
 459}
 460
 461static int ocfs2_block_group_claim_bits(struct ocfs2_super *osb,
 462					handle_t *handle,
 463					struct ocfs2_alloc_context *ac,
 464					unsigned int min_bits,
 465					u32 *bit_off, u32 *num_bits)
 466{
 467	int status = 0;
 468
 469	while (min_bits) {
 470		status = ocfs2_claim_clusters(handle, ac, min_bits,
 471					      bit_off, num_bits);
 472		if (status != -ENOSPC)
 473			break;
 474
 475		min_bits >>= 1;
 476	}
 477
 478	return status;
 479}
 480
 481static int ocfs2_block_group_grow_discontig(handle_t *handle,
 482					    struct inode *alloc_inode,
 483					    struct buffer_head *bg_bh,
 484					    struct ocfs2_alloc_context *ac,
 485					    struct ocfs2_chain_list *cl,
 486					    unsigned int min_bits)
 487{
 488	int status;
 489	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 490	struct ocfs2_group_desc *bg =
 491		(struct ocfs2_group_desc *)bg_bh->b_data;
 492	unsigned int needed = le16_to_cpu(cl->cl_cpg) -
 493			 le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
 494	u32 p_cpos, clusters;
 495	u64 p_blkno;
 496	struct ocfs2_extent_list *el = &bg->bg_list;
 497
 498	status = ocfs2_journal_access_gd(handle,
 499					 INODE_CACHE(alloc_inode),
 500					 bg_bh,
 501					 OCFS2_JOURNAL_ACCESS_CREATE);
 502	if (status < 0) {
 503		mlog_errno(status);
 504		goto bail;
 505	}
 506
 507	while ((needed > 0) && (le16_to_cpu(el->l_next_free_rec) <
 508				le16_to_cpu(el->l_count))) {
 509		if (min_bits > needed)
 510			min_bits = needed;
 511		status = ocfs2_block_group_claim_bits(osb, handle, ac,
 512						      min_bits, &p_cpos,
 513						      &clusters);
 514		if (status < 0) {
 515			if (status != -ENOSPC)
 516				mlog_errno(status);
 517			goto bail;
 518		}
 519		p_blkno = ocfs2_clusters_to_blocks(osb->sb, p_cpos);
 520		ocfs2_bg_discontig_add_extent(osb, bg, cl, p_blkno,
 521					      clusters);
 522
 523		min_bits = clusters;
 524		needed = le16_to_cpu(cl->cl_cpg) -
 525			 le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
 526	}
 527
 528	if (needed > 0) {
 529		/*
 530		 * We have used up all the extent rec but can't fill up
 531		 * the cpg. So bail out.
 532		 */
 533		status = -ENOSPC;
 534		goto bail;
 535	}
 536
 537	ocfs2_journal_dirty(handle, bg_bh);
 538
 539bail:
 540	return status;
 541}
 542
 543static void ocfs2_bg_alloc_cleanup(handle_t *handle,
 544				   struct ocfs2_alloc_context *cluster_ac,
 545				   struct inode *alloc_inode,
 546				   struct buffer_head *bg_bh)
 547{
 548	int i, ret;
 549	struct ocfs2_group_desc *bg;
 550	struct ocfs2_extent_list *el;
 551	struct ocfs2_extent_rec *rec;
 552
 553	if (!bg_bh)
 554		return;
 555
 556	bg = (struct ocfs2_group_desc *)bg_bh->b_data;
 557	el = &bg->bg_list;
 558	for (i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
 559		rec = &el->l_recs[i];
 560		ret = ocfs2_free_clusters(handle, cluster_ac->ac_inode,
 561					  cluster_ac->ac_bh,
 562					  le64_to_cpu(rec->e_blkno),
 563					  le16_to_cpu(rec->e_leaf_clusters));
 564		if (ret)
 565			mlog_errno(ret);
 566		/* Try all the clusters to free */
 567	}
 568
 569	ocfs2_remove_from_cache(INODE_CACHE(alloc_inode), bg_bh);
 570	brelse(bg_bh);
 571}
 572
 573static struct buffer_head *
 574ocfs2_block_group_alloc_discontig(handle_t *handle,
 575				  struct inode *alloc_inode,
 576				  struct ocfs2_alloc_context *ac,
 577				  struct ocfs2_chain_list *cl)
 578{
 579	int status;
 580	u32 bit_off, num_bits;
 581	u64 bg_blkno;
 582	unsigned int min_bits = le16_to_cpu(cl->cl_cpg) >> 1;
 583	struct buffer_head *bg_bh = NULL;
 584	unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
 585	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 586
 587	if (!ocfs2_supports_discontig_bg(osb)) {
 588		status = -ENOSPC;
 589		goto bail;
 590	}
 591
 592	status = ocfs2_extend_trans(handle,
 593				    ocfs2_calc_bg_discontig_credits(osb->sb));
 594	if (status) {
 595		mlog_errno(status);
 596		goto bail;
 597	}
 598
 599	/*
 600	 * We're going to be grabbing from multiple cluster groups.
 601	 * We don't have enough credits to relink them all, and the
 602	 * cluster groups will be staying in cache for the duration of
 603	 * this operation.
 604	 */
 605	ac->ac_disable_chain_relink = 1;
 606
 607	/* Claim the first region */
 608	status = ocfs2_block_group_claim_bits(osb, handle, ac, min_bits,
 609					      &bit_off, &num_bits);
 610	if (status < 0) {
 611		if (status != -ENOSPC)
 612			mlog_errno(status);
 613		goto bail;
 614	}
 615	min_bits = num_bits;
 616
 617	/* setup the group */
 618	bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 619	trace_ocfs2_block_group_alloc_discontig(
 620				(unsigned long long)bg_blkno, alloc_rec);
 621
 622	bg_bh = sb_getblk(osb->sb, bg_blkno);
 623	if (!bg_bh) {
 624		status = -ENOMEM;
 625		mlog_errno(status);
 626		goto bail;
 627	}
 628	ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
 629
 630	status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
 631					bg_blkno, num_bits, alloc_rec, cl);
 632	if (status < 0) {
 633		mlog_errno(status);
 634		goto bail;
 635	}
 636
 637	status = ocfs2_block_group_grow_discontig(handle, alloc_inode,
 638						  bg_bh, ac, cl, min_bits);
 639	if (status)
 640		mlog_errno(status);
 641
 642bail:
 643	if (status)
 644		ocfs2_bg_alloc_cleanup(handle, ac, alloc_inode, bg_bh);
 645	return status ? ERR_PTR(status) : bg_bh;
 646}
 647
 648/*
 649 * We expect the block group allocator to already be locked.
 650 */
 651static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
 652				   struct inode *alloc_inode,
 653				   struct buffer_head *bh,
 654				   u64 max_block,
 655				   u64 *last_alloc_group,
 656				   int flags)
 657{
 658	int status, credits;
 659	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) bh->b_data;
 660	struct ocfs2_chain_list *cl;
 661	struct ocfs2_alloc_context *ac = NULL;
 662	handle_t *handle = NULL;
 663	u16 alloc_rec;
 664	struct buffer_head *bg_bh = NULL;
 665	struct ocfs2_group_desc *bg;
 666
 667	BUG_ON(ocfs2_is_cluster_bitmap(alloc_inode));
 668
 669	cl = &fe->id2.i_chain;
 670	status = ocfs2_reserve_clusters_with_limit(osb,
 671						   le16_to_cpu(cl->cl_cpg),
 672						   max_block, flags, &ac);
 673	if (status < 0) {
 674		if (status != -ENOSPC)
 675			mlog_errno(status);
 676		goto bail;
 677	}
 678
 679	credits = ocfs2_calc_group_alloc_credits(osb->sb,
 680						 le16_to_cpu(cl->cl_cpg));
 681	handle = ocfs2_start_trans(osb, credits);
 682	if (IS_ERR(handle)) {
 683		status = PTR_ERR(handle);
 684		handle = NULL;
 685		mlog_errno(status);
 686		goto bail;
 687	}
 688
 689	if (last_alloc_group && *last_alloc_group != 0) {
 690		trace_ocfs2_block_group_alloc(
 691				(unsigned long long)*last_alloc_group);
 692		ac->ac_last_group = *last_alloc_group;
 693	}
 694
 695	bg_bh = ocfs2_block_group_alloc_contig(osb, handle, alloc_inode,
 696					       ac, cl);
 697	if (PTR_ERR(bg_bh) == -ENOSPC)
 698		bg_bh = ocfs2_block_group_alloc_discontig(handle,
 699							  alloc_inode,
 700							  ac, cl);
 701	if (IS_ERR(bg_bh)) {
 702		status = PTR_ERR(bg_bh);
 703		bg_bh = NULL;
 704		if (status != -ENOSPC)
 705			mlog_errno(status);
 706		goto bail;
 707	}
 708	bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 709
 710	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
 711					 bh, OCFS2_JOURNAL_ACCESS_WRITE);
 712	if (status < 0) {
 713		mlog_errno(status);
 714		goto bail;
 715	}
 716
 717	alloc_rec = le16_to_cpu(bg->bg_chain);
 718	le32_add_cpu(&cl->cl_recs[alloc_rec].c_free,
 719		     le16_to_cpu(bg->bg_free_bits_count));
 720	le32_add_cpu(&cl->cl_recs[alloc_rec].c_total,
 721		     le16_to_cpu(bg->bg_bits));
 722	cl->cl_recs[alloc_rec].c_blkno = bg->bg_blkno;
 723	if (le16_to_cpu(cl->cl_next_free_rec) < le16_to_cpu(cl->cl_count))
 724		le16_add_cpu(&cl->cl_next_free_rec, 1);
 725
 726	le32_add_cpu(&fe->id1.bitmap1.i_used, le16_to_cpu(bg->bg_bits) -
 727					le16_to_cpu(bg->bg_free_bits_count));
 728	le32_add_cpu(&fe->id1.bitmap1.i_total, le16_to_cpu(bg->bg_bits));
 729	le32_add_cpu(&fe->i_clusters, le16_to_cpu(cl->cl_cpg));
 730
 731	ocfs2_journal_dirty(handle, bh);
 732
 733	spin_lock(&OCFS2_I(alloc_inode)->ip_lock);
 734	OCFS2_I(alloc_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
 735	fe->i_size = cpu_to_le64(ocfs2_clusters_to_bytes(alloc_inode->i_sb,
 736					     le32_to_cpu(fe->i_clusters)));
 737	spin_unlock(&OCFS2_I(alloc_inode)->ip_lock);
 738	i_size_write(alloc_inode, le64_to_cpu(fe->i_size));
 739	alloc_inode->i_blocks = ocfs2_inode_sector_count(alloc_inode);
 740	ocfs2_update_inode_fsync_trans(handle, alloc_inode, 0);
 741
 742	status = 0;
 743
 744	/* save the new last alloc group so that the caller can cache it. */
 745	if (last_alloc_group)
 746		*last_alloc_group = ac->ac_last_group;
 747
 748bail:
 749	if (handle)
 750		ocfs2_commit_trans(osb, handle);
 751
 752	if (ac)
 753		ocfs2_free_alloc_context(ac);
 754
 755	brelse(bg_bh);
 756
 757	if (status)
 758		mlog_errno(status);
 759	return status;
 760}
 761
 762static int ocfs2_reserve_suballoc_bits(struct ocfs2_super *osb,
 763				       struct ocfs2_alloc_context *ac,
 764				       int type,
 765				       u32 slot,
 766				       u64 *last_alloc_group,
 767				       int flags)
 768{
 769	int status;
 770	u32 bits_wanted = ac->ac_bits_wanted;
 771	struct inode *alloc_inode;
 772	struct buffer_head *bh = NULL;
 773	struct ocfs2_dinode *fe;
 774	u32 free_bits;
 775
 776	alloc_inode = ocfs2_get_system_file_inode(osb, type, slot);
 777	if (!alloc_inode) {
 778		mlog_errno(-EINVAL);
 779		return -EINVAL;
 780	}
 781
 782	inode_lock(alloc_inode);
 783
 784	status = ocfs2_inode_lock(alloc_inode, &bh, 1);
 785	if (status < 0) {
 786		inode_unlock(alloc_inode);
 787		iput(alloc_inode);
 788
 789		mlog_errno(status);
 790		return status;
 791	}
 792
 793	ac->ac_inode = alloc_inode;
 794	ac->ac_alloc_slot = slot;
 795
 796	fe = (struct ocfs2_dinode *) bh->b_data;
 797
 798	/* The bh was validated by the inode read inside
 799	 * ocfs2_inode_lock().  Any corruption is a code bug. */
 800	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
 801
 802	if (!(fe->i_flags & cpu_to_le32(OCFS2_CHAIN_FL))) {
 803		status = ocfs2_error(alloc_inode->i_sb,
 804				     "Invalid chain allocator %llu\n",
 805				     (unsigned long long)le64_to_cpu(fe->i_blkno));
 806		goto bail;
 807	}
 808
 809	free_bits = le32_to_cpu(fe->id1.bitmap1.i_total) -
 810		le32_to_cpu(fe->id1.bitmap1.i_used);
 811
 812	if (bits_wanted > free_bits) {
 813		/* cluster bitmap never grows */
 814		if (ocfs2_is_cluster_bitmap(alloc_inode)) {
 815			trace_ocfs2_reserve_suballoc_bits_nospc(bits_wanted,
 816								free_bits);
 817			status = -ENOSPC;
 818			goto bail;
 819		}
 820
 821		if (!(flags & ALLOC_NEW_GROUP)) {
 822			trace_ocfs2_reserve_suballoc_bits_no_new_group(
 823						slot, bits_wanted, free_bits);
 824			status = -ENOSPC;
 825			goto bail;
 826		}
 827
 828		status = ocfs2_block_group_alloc(osb, alloc_inode, bh,
 829						 ac->ac_max_block,
 830						 last_alloc_group, flags);
 831		if (status < 0) {
 832			if (status != -ENOSPC)
 833				mlog_errno(status);
 834			goto bail;
 835		}
 836		atomic_inc(&osb->alloc_stats.bg_extends);
 837
 838		/* You should never ask for this much metadata */
 839		BUG_ON(bits_wanted >
 840		       (le32_to_cpu(fe->id1.bitmap1.i_total)
 841			- le32_to_cpu(fe->id1.bitmap1.i_used)));
 842	}
 843
 844	get_bh(bh);
 845	ac->ac_bh = bh;
 846bail:
 847	brelse(bh);
 848
 849	if (status)
 850		mlog_errno(status);
 851	return status;
 852}
 853
 854static void ocfs2_init_inode_steal_slot(struct ocfs2_super *osb)
 855{
 856	spin_lock(&osb->osb_lock);
 857	osb->s_inode_steal_slot = OCFS2_INVALID_SLOT;
 858	spin_unlock(&osb->osb_lock);
 859	atomic_set(&osb->s_num_inodes_stolen, 0);
 860}
 861
 862static void ocfs2_init_meta_steal_slot(struct ocfs2_super *osb)
 863{
 864	spin_lock(&osb->osb_lock);
 865	osb->s_meta_steal_slot = OCFS2_INVALID_SLOT;
 866	spin_unlock(&osb->osb_lock);
 867	atomic_set(&osb->s_num_meta_stolen, 0);
 868}
 869
 870void ocfs2_init_steal_slots(struct ocfs2_super *osb)
 871{
 872	ocfs2_init_inode_steal_slot(osb);
 873	ocfs2_init_meta_steal_slot(osb);
 874}
 875
 876static void __ocfs2_set_steal_slot(struct ocfs2_super *osb, int slot, int type)
 877{
 878	spin_lock(&osb->osb_lock);
 879	if (type == INODE_ALLOC_SYSTEM_INODE)
 880		osb->s_inode_steal_slot = (u16)slot;
 881	else if (type == EXTENT_ALLOC_SYSTEM_INODE)
 882		osb->s_meta_steal_slot = (u16)slot;
 883	spin_unlock(&osb->osb_lock);
 884}
 885
 886static int __ocfs2_get_steal_slot(struct ocfs2_super *osb, int type)
 887{
 888	int slot = OCFS2_INVALID_SLOT;
 889
 890	spin_lock(&osb->osb_lock);
 891	if (type == INODE_ALLOC_SYSTEM_INODE)
 892		slot = osb->s_inode_steal_slot;
 893	else if (type == EXTENT_ALLOC_SYSTEM_INODE)
 894		slot = osb->s_meta_steal_slot;
 895	spin_unlock(&osb->osb_lock);
 896
 897	return slot;
 898}
 899
 900static int ocfs2_get_inode_steal_slot(struct ocfs2_super *osb)
 901{
 902	return __ocfs2_get_steal_slot(osb, INODE_ALLOC_SYSTEM_INODE);
 903}
 904
 905static int ocfs2_get_meta_steal_slot(struct ocfs2_super *osb)
 906{
 907	return __ocfs2_get_steal_slot(osb, EXTENT_ALLOC_SYSTEM_INODE);
 908}
 909
 910static int ocfs2_steal_resource(struct ocfs2_super *osb,
 911				struct ocfs2_alloc_context *ac,
 912				int type)
 913{
 914	int i, status = -ENOSPC;
 915	int slot = __ocfs2_get_steal_slot(osb, type);
 916
 917	/* Start to steal resource from the first slot after ours. */
 918	if (slot == OCFS2_INVALID_SLOT)
 919		slot = osb->slot_num + 1;
 920
 921	for (i = 0; i < osb->max_slots; i++, slot++) {
 922		if (slot == osb->max_slots)
 923			slot = 0;
 924
 925		if (slot == osb->slot_num)
 926			continue;
 927
 928		status = ocfs2_reserve_suballoc_bits(osb, ac,
 929						     type,
 930						     (u32)slot, NULL,
 931						     NOT_ALLOC_NEW_GROUP);
 932		if (status >= 0) {
 933			__ocfs2_set_steal_slot(osb, slot, type);
 934			break;
 935		}
 936
 937		ocfs2_free_ac_resource(ac);
 938	}
 939
 940	return status;
 941}
 942
 943static int ocfs2_steal_inode(struct ocfs2_super *osb,
 944			     struct ocfs2_alloc_context *ac)
 945{
 946	return ocfs2_steal_resource(osb, ac, INODE_ALLOC_SYSTEM_INODE);
 947}
 948
 949static int ocfs2_steal_meta(struct ocfs2_super *osb,
 950			    struct ocfs2_alloc_context *ac)
 951{
 952	return ocfs2_steal_resource(osb, ac, EXTENT_ALLOC_SYSTEM_INODE);
 953}
 954
 955int ocfs2_reserve_new_metadata_blocks(struct ocfs2_super *osb,
 956				      int blocks,
 957				      struct ocfs2_alloc_context **ac)
 958{
 959	int status;
 960	int slot = ocfs2_get_meta_steal_slot(osb);
 961
 962	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 963	if (!(*ac)) {
 964		status = -ENOMEM;
 965		mlog_errno(status);
 966		goto bail;
 967	}
 968
 969	(*ac)->ac_bits_wanted = blocks;
 970	(*ac)->ac_which = OCFS2_AC_USE_META;
 971	(*ac)->ac_group_search = ocfs2_block_group_search;
 972
 973	if (slot != OCFS2_INVALID_SLOT &&
 974		atomic_read(&osb->s_num_meta_stolen) < OCFS2_MAX_TO_STEAL)
 975		goto extent_steal;
 976
 977	atomic_set(&osb->s_num_meta_stolen, 0);
 978	status = ocfs2_reserve_suballoc_bits(osb, (*ac),
 979					     EXTENT_ALLOC_SYSTEM_INODE,
 980					     (u32)osb->slot_num, NULL,
 981					     ALLOC_GROUPS_FROM_GLOBAL|ALLOC_NEW_GROUP);
 982
 983
 984	if (status >= 0) {
 985		status = 0;
 986		if (slot != OCFS2_INVALID_SLOT)
 987			ocfs2_init_meta_steal_slot(osb);
 988		goto bail;
 989	} else if (status < 0 && status != -ENOSPC) {
 990		mlog_errno(status);
 991		goto bail;
 992	}
 993
 994	ocfs2_free_ac_resource(*ac);
 995
 996extent_steal:
 997	status = ocfs2_steal_meta(osb, *ac);
 998	atomic_inc(&osb->s_num_meta_stolen);
 999	if (status < 0) {
1000		if (status != -ENOSPC)
1001			mlog_errno(status);
1002		goto bail;
1003	}
1004
1005	status = 0;
1006bail:
1007	if ((status < 0) && *ac) {
1008		ocfs2_free_alloc_context(*ac);
1009		*ac = NULL;
1010	}
1011
1012	if (status)
1013		mlog_errno(status);
1014	return status;
1015}
1016
1017int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
1018			       struct ocfs2_extent_list *root_el,
1019			       struct ocfs2_alloc_context **ac)
1020{
1021	return ocfs2_reserve_new_metadata_blocks(osb,
1022					ocfs2_extend_meta_needed(root_el),
1023					ac);
1024}
1025
1026int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
1027			    struct ocfs2_alloc_context **ac)
1028{
1029	int status;
1030	int slot = ocfs2_get_inode_steal_slot(osb);
1031	u64 alloc_group;
1032
1033	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1034	if (!(*ac)) {
1035		status = -ENOMEM;
1036		mlog_errno(status);
1037		goto bail;
1038	}
1039
1040	(*ac)->ac_bits_wanted = 1;
1041	(*ac)->ac_which = OCFS2_AC_USE_INODE;
1042
1043	(*ac)->ac_group_search = ocfs2_block_group_search;
1044
1045	/*
1046	 * stat(2) can't handle i_ino > 32bits, so we tell the
1047	 * lower levels not to allocate us a block group past that
1048	 * limit.  The 'inode64' mount option avoids this behavior.
1049	 */
1050	if (!(osb->s_mount_opt & OCFS2_MOUNT_INODE64))
1051		(*ac)->ac_max_block = (u32)~0U;
1052
1053	/*
1054	 * slot is set when we successfully steal inode from other nodes.
1055	 * It is reset in 3 places:
1056	 * 1. when we flush the truncate log
1057	 * 2. when we complete local alloc recovery.
1058	 * 3. when we successfully allocate from our own slot.
1059	 * After it is set, we will go on stealing inodes until we find the
1060	 * need to check our slots to see whether there is some space for us.
1061	 */
1062	if (slot != OCFS2_INVALID_SLOT &&
1063	    atomic_read(&osb->s_num_inodes_stolen) < OCFS2_MAX_TO_STEAL)
1064		goto inode_steal;
1065
1066	atomic_set(&osb->s_num_inodes_stolen, 0);
1067	alloc_group = osb->osb_inode_alloc_group;
1068	status = ocfs2_reserve_suballoc_bits(osb, *ac,
1069					     INODE_ALLOC_SYSTEM_INODE,
1070					     (u32)osb->slot_num,
1071					     &alloc_group,
1072					     ALLOC_NEW_GROUP |
1073					     ALLOC_GROUPS_FROM_GLOBAL);
1074	if (status >= 0) {
1075		status = 0;
1076
1077		spin_lock(&osb->osb_lock);
1078		osb->osb_inode_alloc_group = alloc_group;
1079		spin_unlock(&osb->osb_lock);
1080		trace_ocfs2_reserve_new_inode_new_group(
1081			(unsigned long long)alloc_group);
1082
1083		/*
1084		 * Some inodes must be freed by us, so try to allocate
1085		 * from our own next time.
1086		 */
1087		if (slot != OCFS2_INVALID_SLOT)
1088			ocfs2_init_inode_steal_slot(osb);
1089		goto bail;
1090	} else if (status < 0 && status != -ENOSPC) {
1091		mlog_errno(status);
1092		goto bail;
1093	}
1094
1095	ocfs2_free_ac_resource(*ac);
1096
1097inode_steal:
1098	status = ocfs2_steal_inode(osb, *ac);
1099	atomic_inc(&osb->s_num_inodes_stolen);
1100	if (status < 0) {
1101		if (status != -ENOSPC)
1102			mlog_errno(status);
1103		goto bail;
1104	}
1105
1106	status = 0;
1107bail:
1108	if ((status < 0) && *ac) {
1109		ocfs2_free_alloc_context(*ac);
1110		*ac = NULL;
1111	}
1112
1113	if (status)
1114		mlog_errno(status);
1115	return status;
1116}
1117
1118/* local alloc code has to do the same thing, so rather than do this
1119 * twice.. */
1120int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
1121				      struct ocfs2_alloc_context *ac)
1122{
1123	int status;
1124
1125	ac->ac_which = OCFS2_AC_USE_MAIN;
1126	ac->ac_group_search = ocfs2_cluster_group_search;
1127
1128	status = ocfs2_reserve_suballoc_bits(osb, ac,
1129					     GLOBAL_BITMAP_SYSTEM_INODE,
1130					     OCFS2_INVALID_SLOT, NULL,
1131					     ALLOC_NEW_GROUP);
1132	if (status < 0 && status != -ENOSPC)
1133		mlog_errno(status);
 
 
1134
 
1135	return status;
1136}
1137
1138/* Callers don't need to care which bitmap (local alloc or main) to
1139 * use so we figure it out for them, but unfortunately this clutters
1140 * things a bit. */
1141static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
1142					     u32 bits_wanted, u64 max_block,
1143					     int flags,
1144					     struct ocfs2_alloc_context **ac)
1145{
1146	int status, ret = 0;
1147	int retried = 0;
1148
1149	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1150	if (!(*ac)) {
1151		status = -ENOMEM;
1152		mlog_errno(status);
1153		goto bail;
1154	}
1155
1156	(*ac)->ac_bits_wanted = bits_wanted;
1157	(*ac)->ac_max_block = max_block;
1158
1159	status = -ENOSPC;
1160	if (!(flags & ALLOC_GROUPS_FROM_GLOBAL) &&
1161	    ocfs2_alloc_should_use_local(osb, bits_wanted)) {
1162		status = ocfs2_reserve_local_alloc_bits(osb,
1163							bits_wanted,
1164							*ac);
1165		if ((status < 0) && (status != -ENOSPC)) {
1166			mlog_errno(status);
1167			goto bail;
1168		}
1169	}
1170
1171	if (status == -ENOSPC) {
1172retry:
1173		status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
1174		/* Retry if there is sufficient space cached in truncate log */
1175		if (status == -ENOSPC && !retried) {
1176			retried = 1;
1177			ocfs2_inode_unlock((*ac)->ac_inode, 1);
1178			inode_unlock((*ac)->ac_inode);
1179
1180			ret = ocfs2_try_to_free_truncate_log(osb, bits_wanted);
1181			if (ret == 1) {
1182				iput((*ac)->ac_inode);
1183				(*ac)->ac_inode = NULL;
1184				goto retry;
1185			}
1186
1187			if (ret < 0)
1188				mlog_errno(ret);
1189
1190			inode_lock((*ac)->ac_inode);
1191			ret = ocfs2_inode_lock((*ac)->ac_inode, NULL, 1);
1192			if (ret < 0) {
1193				mlog_errno(ret);
1194				inode_unlock((*ac)->ac_inode);
1195				iput((*ac)->ac_inode);
1196				(*ac)->ac_inode = NULL;
1197				goto bail;
1198			}
1199		}
1200		if (status < 0) {
1201			if (status != -ENOSPC)
1202				mlog_errno(status);
1203			goto bail;
1204		}
1205	}
1206
1207	status = 0;
1208bail:
1209	if ((status < 0) && *ac) {
1210		ocfs2_free_alloc_context(*ac);
1211		*ac = NULL;
1212	}
1213
1214	if (status)
1215		mlog_errno(status);
1216	return status;
1217}
1218
1219int ocfs2_reserve_clusters(struct ocfs2_super *osb,
1220			   u32 bits_wanted,
1221			   struct ocfs2_alloc_context **ac)
1222{
1223	return ocfs2_reserve_clusters_with_limit(osb, bits_wanted, 0,
1224						 ALLOC_NEW_GROUP, ac);
1225}
1226
1227/*
1228 * More or less lifted from ext3. I'll leave their description below:
1229 *
1230 * "For ext3 allocations, we must not reuse any blocks which are
1231 * allocated in the bitmap buffer's "last committed data" copy.  This
1232 * prevents deletes from freeing up the page for reuse until we have
1233 * committed the delete transaction.
1234 *
1235 * If we didn't do this, then deleting something and reallocating it as
1236 * data would allow the old block to be overwritten before the
1237 * transaction committed (because we force data to disk before commit).
1238 * This would lead to corruption if we crashed between overwriting the
1239 * data and committing the delete.
1240 *
1241 * @@@ We may want to make this allocation behaviour conditional on
1242 * data-writes at some point, and disable it for metadata allocations or
1243 * sync-data inodes."
1244 *
1245 * Note: OCFS2 already does this differently for metadata vs data
1246 * allocations, as those bitmaps are separate and undo access is never
1247 * called on a metadata group descriptor.
1248 */
1249static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
1250					 int nr)
1251{
1252	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1253	struct journal_head *jh;
1254	int ret;
1255
1256	if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
1257		return 0;
1258
1259	jh = jbd2_journal_grab_journal_head(bg_bh);
1260	if (!jh)
1261		return 1;
1262
1263	spin_lock(&jh->b_state_lock);
1264	bg = (struct ocfs2_group_desc *) jh->b_committed_data;
1265	if (bg)
1266		ret = !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
1267	else
1268		ret = 1;
1269	spin_unlock(&jh->b_state_lock);
1270	jbd2_journal_put_journal_head(jh);
1271
1272	return ret;
1273}
1274
1275static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
1276					     struct buffer_head *bg_bh,
1277					     unsigned int bits_wanted,
1278					     unsigned int total_bits,
1279					     struct ocfs2_suballoc_result *res)
1280{
1281	void *bitmap;
1282	u16 best_offset, best_size;
1283	int offset, start, found, status = 0;
1284	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1285
1286	/* Callers got this descriptor from
1287	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1288	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1289
1290	found = start = best_offset = best_size = 0;
1291	bitmap = bg->bg_bitmap;
1292
1293	while ((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) <
1294	       total_bits) {
 
 
1295		if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
1296			/* We found a zero, but we can't use it as it
1297			 * hasn't been put to disk yet! */
1298			found = 0;
1299			start = offset + 1;
1300		} else if (offset == start) {
1301			/* we found a zero */
1302			found++;
1303			/* move start to the next bit to test */
1304			start++;
1305		} else {
1306			/* got a zero after some ones */
1307			found = 1;
1308			start = offset + 1;
1309		}
1310		if (found > best_size) {
1311			best_size = found;
1312			best_offset = start - found;
1313		}
1314		/* we got everything we needed */
1315		if (found == bits_wanted) {
1316			/* mlog(0, "Found it all!\n"); */
1317			break;
1318		}
1319	}
1320
1321	if (best_size) {
1322		res->sr_bit_offset = best_offset;
1323		res->sr_bits = best_size;
1324	} else {
1325		status = -ENOSPC;
1326		/* No error log here -- see the comment above
1327		 * ocfs2_test_bg_bit_allocatable */
1328	}
1329
1330	return status;
1331}
1332
1333int ocfs2_block_group_set_bits(handle_t *handle,
1334					     struct inode *alloc_inode,
1335					     struct ocfs2_group_desc *bg,
1336					     struct buffer_head *group_bh,
1337					     unsigned int bit_off,
1338					     unsigned int num_bits)
1339{
1340	int status;
1341	void *bitmap = bg->bg_bitmap;
1342	int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1343
1344	/* All callers get the descriptor via
1345	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1346	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1347	BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
1348
1349	trace_ocfs2_block_group_set_bits(bit_off, num_bits);
1350
1351	if (ocfs2_is_cluster_bitmap(alloc_inode))
1352		journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1353
1354	status = ocfs2_journal_access_gd(handle,
1355					 INODE_CACHE(alloc_inode),
1356					 group_bh,
1357					 journal_type);
1358	if (status < 0) {
1359		mlog_errno(status);
1360		goto bail;
1361	}
1362
1363	le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
1364	if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
1365		return ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit count %u but claims %u are freed. num_bits %d\n",
1366				   (unsigned long long)le64_to_cpu(bg->bg_blkno),
1367				   le16_to_cpu(bg->bg_bits),
1368				   le16_to_cpu(bg->bg_free_bits_count),
1369				   num_bits);
1370	}
1371	while(num_bits--)
1372		ocfs2_set_bit(bit_off++, bitmap);
1373
1374	ocfs2_journal_dirty(handle, group_bh);
1375
1376bail:
1377	return status;
1378}
1379
1380/* find the one with the most empty bits */
1381static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
1382{
1383	u16 curr, best;
1384
1385	BUG_ON(!cl->cl_next_free_rec);
1386
1387	best = curr = 0;
1388	while (curr < le16_to_cpu(cl->cl_next_free_rec)) {
1389		if (le32_to_cpu(cl->cl_recs[curr].c_free) >
1390		    le32_to_cpu(cl->cl_recs[best].c_free))
1391			best = curr;
1392		curr++;
1393	}
1394
1395	BUG_ON(best >= le16_to_cpu(cl->cl_next_free_rec));
1396	return best;
1397}
1398
1399static int ocfs2_relink_block_group(handle_t *handle,
1400				    struct inode *alloc_inode,
1401				    struct buffer_head *fe_bh,
1402				    struct buffer_head *bg_bh,
1403				    struct buffer_head *prev_bg_bh,
1404				    u16 chain)
1405{
1406	int status;
1407	/* there is a really tiny chance the journal calls could fail,
1408	 * but we wouldn't want inconsistent blocks in *any* case. */
1409	u64 bg_ptr, prev_bg_ptr;
1410	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
1411	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1412	struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
1413
1414	/* The caller got these descriptors from
1415	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1416	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1417	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(prev_bg));
1418
1419	trace_ocfs2_relink_block_group(
1420		(unsigned long long)le64_to_cpu(fe->i_blkno), chain,
1421		(unsigned long long)le64_to_cpu(bg->bg_blkno),
1422		(unsigned long long)le64_to_cpu(prev_bg->bg_blkno));
1423
1424	bg_ptr = le64_to_cpu(bg->bg_next_group);
1425	prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
1426
1427	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1428					 prev_bg_bh,
1429					 OCFS2_JOURNAL_ACCESS_WRITE);
1430	if (status < 0)
1431		goto out;
1432
1433	prev_bg->bg_next_group = bg->bg_next_group;
1434	ocfs2_journal_dirty(handle, prev_bg_bh);
1435
1436	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1437					 bg_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1438	if (status < 0)
1439		goto out_rollback_prev_bg;
1440
1441	bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
1442	ocfs2_journal_dirty(handle, bg_bh);
1443
1444	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
1445					 fe_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1446	if (status < 0)
1447		goto out_rollback_bg;
1448
1449	fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
1450	ocfs2_journal_dirty(handle, fe_bh);
1451
1452out:
1453	if (status < 0)
1454		mlog_errno(status);
1455	return status;
1456
1457out_rollback_bg:
1458	bg->bg_next_group = cpu_to_le64(bg_ptr);
1459out_rollback_prev_bg:
1460	prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
1461	goto out;
1462}
1463
1464static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
1465						     u32 wanted)
1466{
1467	return le16_to_cpu(bg->bg_free_bits_count) > wanted;
1468}
1469
1470/* return 0 on success, -ENOSPC to keep searching and any other < 0
1471 * value on error. */
1472static int ocfs2_cluster_group_search(struct inode *inode,
1473				      struct buffer_head *group_bh,
1474				      u32 bits_wanted, u32 min_bits,
1475				      u64 max_block,
1476				      struct ocfs2_suballoc_result *res)
1477{
1478	int search = -ENOSPC;
1479	int ret;
1480	u64 blkoff;
1481	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
1482	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1483	unsigned int max_bits, gd_cluster_off;
1484
1485	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1486
1487	if (gd->bg_free_bits_count) {
1488		max_bits = le16_to_cpu(gd->bg_bits);
1489
1490		/* Tail groups in cluster bitmaps which aren't cpg
1491		 * aligned are prone to partial extension by a failed
1492		 * fs resize. If the file system resize never got to
1493		 * update the dinode cluster count, then we don't want
1494		 * to trust any clusters past it, regardless of what
1495		 * the group descriptor says. */
1496		gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
1497							  le64_to_cpu(gd->bg_blkno));
1498		if ((gd_cluster_off + max_bits) >
1499		    OCFS2_I(inode)->ip_clusters) {
1500			max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
1501			trace_ocfs2_cluster_group_search_wrong_max_bits(
1502				(unsigned long long)le64_to_cpu(gd->bg_blkno),
1503				le16_to_cpu(gd->bg_bits),
1504				OCFS2_I(inode)->ip_clusters, max_bits);
1505		}
1506
1507		ret = ocfs2_block_group_find_clear_bits(osb,
1508							group_bh, bits_wanted,
1509							max_bits, res);
1510		if (ret)
1511			return ret;
1512
1513		if (max_block) {
1514			blkoff = ocfs2_clusters_to_blocks(inode->i_sb,
1515							  gd_cluster_off +
1516							  res->sr_bit_offset +
1517							  res->sr_bits);
1518			trace_ocfs2_cluster_group_search_max_block(
1519				(unsigned long long)blkoff,
1520				(unsigned long long)max_block);
1521			if (blkoff > max_block)
1522				return -ENOSPC;
1523		}
1524
1525		/* ocfs2_block_group_find_clear_bits() might
1526		 * return success, but we still want to return
1527		 * -ENOSPC unless it found the minimum number
1528		 * of bits. */
1529		if (min_bits <= res->sr_bits)
1530			search = 0; /* success */
1531		else if (res->sr_bits) {
1532			/*
1533			 * Don't show bits which we'll be returning
1534			 * for allocation to the local alloc bitmap.
1535			 */
1536			ocfs2_local_alloc_seen_free_bits(osb, res->sr_bits);
1537		}
1538	}
1539
1540	return search;
1541}
1542
1543static int ocfs2_block_group_search(struct inode *inode,
1544				    struct buffer_head *group_bh,
1545				    u32 bits_wanted, u32 min_bits,
1546				    u64 max_block,
1547				    struct ocfs2_suballoc_result *res)
1548{
1549	int ret = -ENOSPC;
1550	u64 blkoff;
1551	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
1552
1553	BUG_ON(min_bits != 1);
1554	BUG_ON(ocfs2_is_cluster_bitmap(inode));
1555
1556	if (bg->bg_free_bits_count) {
1557		ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1558							group_bh, bits_wanted,
1559							le16_to_cpu(bg->bg_bits),
1560							res);
1561		if (!ret && max_block) {
1562			blkoff = le64_to_cpu(bg->bg_blkno) +
1563				res->sr_bit_offset + res->sr_bits;
1564			trace_ocfs2_block_group_search_max_block(
1565				(unsigned long long)blkoff,
1566				(unsigned long long)max_block);
1567			if (blkoff > max_block)
1568				ret = -ENOSPC;
1569		}
1570	}
1571
1572	return ret;
1573}
1574
1575int ocfs2_alloc_dinode_update_counts(struct inode *inode,
1576				       handle_t *handle,
1577				       struct buffer_head *di_bh,
1578				       u32 num_bits,
1579				       u16 chain)
1580{
1581	int ret;
1582	u32 tmp_used;
1583	struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1584	struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &di->id2.i_chain;
1585
1586	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
1587				      OCFS2_JOURNAL_ACCESS_WRITE);
1588	if (ret < 0) {
1589		mlog_errno(ret);
1590		goto out;
1591	}
1592
1593	tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1594	di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
1595	le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
1596	ocfs2_journal_dirty(handle, di_bh);
1597
1598out:
1599	return ret;
1600}
1601
1602void ocfs2_rollback_alloc_dinode_counts(struct inode *inode,
1603				       struct buffer_head *di_bh,
1604				       u32 num_bits,
1605				       u16 chain)
1606{
1607	u32 tmp_used;
1608	struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1609	struct ocfs2_chain_list *cl;
1610
1611	cl = (struct ocfs2_chain_list *)&di->id2.i_chain;
1612	tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1613	di->id1.bitmap1.i_used = cpu_to_le32(tmp_used - num_bits);
1614	le32_add_cpu(&cl->cl_recs[chain].c_free, num_bits);
1615}
1616
1617static int ocfs2_bg_discontig_fix_by_rec(struct ocfs2_suballoc_result *res,
1618					 struct ocfs2_extent_rec *rec,
1619					 struct ocfs2_chain_list *cl)
1620{
1621	unsigned int bpc = le16_to_cpu(cl->cl_bpc);
1622	unsigned int bitoff = le32_to_cpu(rec->e_cpos) * bpc;
1623	unsigned int bitcount = le16_to_cpu(rec->e_leaf_clusters) * bpc;
1624
1625	if (res->sr_bit_offset < bitoff)
1626		return 0;
1627	if (res->sr_bit_offset >= (bitoff + bitcount))
1628		return 0;
1629	res->sr_blkno = le64_to_cpu(rec->e_blkno) +
1630		(res->sr_bit_offset - bitoff);
1631	if ((res->sr_bit_offset + res->sr_bits) > (bitoff + bitcount))
1632		res->sr_bits = (bitoff + bitcount) - res->sr_bit_offset;
1633	return 1;
1634}
1635
1636static void ocfs2_bg_discontig_fix_result(struct ocfs2_alloc_context *ac,
1637					  struct ocfs2_group_desc *bg,
1638					  struct ocfs2_suballoc_result *res)
1639{
1640	int i;
1641	u64 bg_blkno = res->sr_bg_blkno;  /* Save off */
1642	struct ocfs2_extent_rec *rec;
1643	struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1644	struct ocfs2_chain_list *cl = &di->id2.i_chain;
1645
1646	if (ocfs2_is_cluster_bitmap(ac->ac_inode)) {
1647		res->sr_blkno = 0;
1648		return;
1649	}
1650
1651	res->sr_blkno = res->sr_bg_blkno + res->sr_bit_offset;
1652	res->sr_bg_blkno = 0;  /* Clear it for contig block groups */
1653	if (!ocfs2_supports_discontig_bg(OCFS2_SB(ac->ac_inode->i_sb)) ||
1654	    !bg->bg_list.l_next_free_rec)
1655		return;
1656
1657	for (i = 0; i < le16_to_cpu(bg->bg_list.l_next_free_rec); i++) {
1658		rec = &bg->bg_list.l_recs[i];
1659		if (ocfs2_bg_discontig_fix_by_rec(res, rec, cl)) {
1660			res->sr_bg_blkno = bg_blkno;  /* Restore */
1661			break;
1662		}
1663	}
1664}
1665
1666static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
1667				  handle_t *handle,
1668				  u32 bits_wanted,
1669				  u32 min_bits,
1670				  struct ocfs2_suballoc_result *res,
1671				  u16 *bits_left)
1672{
1673	int ret;
1674	struct buffer_head *group_bh = NULL;
1675	struct ocfs2_group_desc *gd;
1676	struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1677	struct inode *alloc_inode = ac->ac_inode;
1678
1679	ret = ocfs2_read_group_descriptor(alloc_inode, di,
1680					  res->sr_bg_blkno, &group_bh);
1681	if (ret < 0) {
1682		mlog_errno(ret);
1683		return ret;
1684	}
1685
1686	gd = (struct ocfs2_group_desc *) group_bh->b_data;
1687	ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
1688				  ac->ac_max_block, res);
1689	if (ret < 0) {
1690		if (ret != -ENOSPC)
1691			mlog_errno(ret);
1692		goto out;
1693	}
1694
1695	if (!ret)
1696		ocfs2_bg_discontig_fix_result(ac, gd, res);
1697
1698	/*
1699	 * sr_bg_blkno might have been changed by
1700	 * ocfs2_bg_discontig_fix_result
1701	 */
1702	res->sr_bg_stable_blkno = group_bh->b_blocknr;
1703
1704	if (ac->ac_find_loc_only)
1705		goto out_loc_only;
1706
1707	ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
1708					       res->sr_bits,
1709					       le16_to_cpu(gd->bg_chain));
1710	if (ret < 0) {
1711		mlog_errno(ret);
1712		goto out;
1713	}
1714
1715	ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
1716					 res->sr_bit_offset, res->sr_bits);
1717	if (ret < 0) {
1718		ocfs2_rollback_alloc_dinode_counts(alloc_inode, ac->ac_bh,
1719					       res->sr_bits,
1720					       le16_to_cpu(gd->bg_chain));
1721		mlog_errno(ret);
1722	}
1723
1724out_loc_only:
1725	*bits_left = le16_to_cpu(gd->bg_free_bits_count);
1726
1727out:
1728	brelse(group_bh);
1729
1730	return ret;
1731}
1732
1733static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
1734			      handle_t *handle,
1735			      u32 bits_wanted,
1736			      u32 min_bits,
1737			      struct ocfs2_suballoc_result *res,
1738			      u16 *bits_left)
1739{
1740	int status;
1741	u16 chain;
1742	u64 next_group;
1743	struct inode *alloc_inode = ac->ac_inode;
1744	struct buffer_head *group_bh = NULL;
1745	struct buffer_head *prev_group_bh = NULL;
1746	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1747	struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1748	struct ocfs2_group_desc *bg;
1749
1750	chain = ac->ac_chain;
1751	trace_ocfs2_search_chain_begin(
1752		(unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
1753		bits_wanted, chain);
1754
1755	status = ocfs2_read_group_descriptor(alloc_inode, fe,
1756					     le64_to_cpu(cl->cl_recs[chain].c_blkno),
1757					     &group_bh);
1758	if (status < 0) {
1759		mlog_errno(status);
1760		goto bail;
1761	}
1762	bg = (struct ocfs2_group_desc *) group_bh->b_data;
1763
1764	status = -ENOSPC;
1765	/* for now, the chain search is a bit simplistic. We just use
1766	 * the 1st group with any empty bits. */
1767	while ((status = ac->ac_group_search(alloc_inode, group_bh,
1768					     bits_wanted, min_bits,
1769					     ac->ac_max_block,
1770					     res)) == -ENOSPC) {
1771		if (!bg->bg_next_group)
1772			break;
1773
1774		brelse(prev_group_bh);
1775		prev_group_bh = NULL;
1776
1777		next_group = le64_to_cpu(bg->bg_next_group);
1778		prev_group_bh = group_bh;
1779		group_bh = NULL;
1780		status = ocfs2_read_group_descriptor(alloc_inode, fe,
1781						     next_group, &group_bh);
1782		if (status < 0) {
1783			mlog_errno(status);
1784			goto bail;
1785		}
1786		bg = (struct ocfs2_group_desc *) group_bh->b_data;
1787	}
1788	if (status < 0) {
1789		if (status != -ENOSPC)
1790			mlog_errno(status);
1791		goto bail;
1792	}
1793
1794	trace_ocfs2_search_chain_succ(
1795		(unsigned long long)le64_to_cpu(bg->bg_blkno), res->sr_bits);
1796
1797	res->sr_bg_blkno = le64_to_cpu(bg->bg_blkno);
1798
1799	BUG_ON(res->sr_bits == 0);
1800	if (!status)
1801		ocfs2_bg_discontig_fix_result(ac, bg, res);
1802
1803	/*
1804	 * sr_bg_blkno might have been changed by
1805	 * ocfs2_bg_discontig_fix_result
1806	 */
1807	res->sr_bg_stable_blkno = group_bh->b_blocknr;
1808
1809	/*
1810	 * Keep track of previous block descriptor read. When
1811	 * we find a target, if we have read more than X
1812	 * number of descriptors, and the target is reasonably
1813	 * empty, relink him to top of his chain.
1814	 *
1815	 * We've read 0 extra blocks and only send one more to
1816	 * the transaction, yet the next guy to search has a
1817	 * much easier time.
1818	 *
1819	 * Do this *after* figuring out how many bits we're taking out
1820	 * of our target group.
1821	 */
1822	if (!ac->ac_disable_chain_relink &&
1823	    (prev_group_bh) &&
1824	    (ocfs2_block_group_reasonably_empty(bg, res->sr_bits))) {
1825		status = ocfs2_relink_block_group(handle, alloc_inode,
1826						  ac->ac_bh, group_bh,
1827						  prev_group_bh, chain);
1828		if (status < 0) {
1829			mlog_errno(status);
1830			goto bail;
1831		}
1832	}
1833
1834	if (ac->ac_find_loc_only)
1835		goto out_loc_only;
1836
1837	status = ocfs2_alloc_dinode_update_counts(alloc_inode, handle,
1838						  ac->ac_bh, res->sr_bits,
1839						  chain);
1840	if (status) {
1841		mlog_errno(status);
1842		goto bail;
1843	}
1844
1845	status = ocfs2_block_group_set_bits(handle,
1846					    alloc_inode,
1847					    bg,
1848					    group_bh,
1849					    res->sr_bit_offset,
1850					    res->sr_bits);
1851	if (status < 0) {
1852		ocfs2_rollback_alloc_dinode_counts(alloc_inode,
1853					ac->ac_bh, res->sr_bits, chain);
1854		mlog_errno(status);
1855		goto bail;
1856	}
1857
1858	trace_ocfs2_search_chain_end(
1859			(unsigned long long)le64_to_cpu(fe->i_blkno),
1860			res->sr_bits);
1861
1862out_loc_only:
1863	*bits_left = le16_to_cpu(bg->bg_free_bits_count);
1864bail:
1865	brelse(group_bh);
1866	brelse(prev_group_bh);
1867
1868	if (status)
1869		mlog_errno(status);
1870	return status;
1871}
1872
1873/* will give out up to bits_wanted contiguous bits. */
1874static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
1875				     handle_t *handle,
1876				     u32 bits_wanted,
1877				     u32 min_bits,
1878				     struct ocfs2_suballoc_result *res)
1879{
1880	int status;
1881	u16 victim, i;
1882	u16 bits_left = 0;
1883	u64 hint = ac->ac_last_group;
1884	struct ocfs2_chain_list *cl;
1885	struct ocfs2_dinode *fe;
1886
1887	BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1888	BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1889	BUG_ON(!ac->ac_bh);
1890
1891	fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1892
1893	/* The bh was validated by the inode read during
1894	 * ocfs2_reserve_suballoc_bits().  Any corruption is a code bug. */
1895	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
1896
1897	if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1898	    le32_to_cpu(fe->id1.bitmap1.i_total)) {
1899		status = ocfs2_error(ac->ac_inode->i_sb,
1900				     "Chain allocator dinode %llu has %u used bits but only %u total\n",
1901				     (unsigned long long)le64_to_cpu(fe->i_blkno),
1902				     le32_to_cpu(fe->id1.bitmap1.i_used),
1903				     le32_to_cpu(fe->id1.bitmap1.i_total));
1904		goto bail;
1905	}
1906
1907	res->sr_bg_blkno = hint;
1908	if (res->sr_bg_blkno) {
1909		/* Attempt to short-circuit the usual search mechanism
1910		 * by jumping straight to the most recently used
1911		 * allocation group. This helps us maintain some
1912		 * contiguousness across allocations. */
1913		status = ocfs2_search_one_group(ac, handle, bits_wanted,
1914						min_bits, res, &bits_left);
1915		if (!status)
1916			goto set_hint;
1917		if (status < 0 && status != -ENOSPC) {
1918			mlog_errno(status);
1919			goto bail;
1920		}
1921	}
1922
1923	cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1924
1925	victim = ocfs2_find_victim_chain(cl);
1926	ac->ac_chain = victim;
1927
1928	status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1929				    res, &bits_left);
1930	if (!status) {
1931		if (ocfs2_is_cluster_bitmap(ac->ac_inode))
1932			hint = res->sr_bg_blkno;
1933		else
1934			hint = ocfs2_group_from_res(res);
1935		goto set_hint;
1936	}
1937	if (status < 0 && status != -ENOSPC) {
1938		mlog_errno(status);
1939		goto bail;
1940	}
1941
1942	trace_ocfs2_claim_suballoc_bits(victim);
1943
1944	/* If we didn't pick a good victim, then just default to
1945	 * searching each chain in order. Don't allow chain relinking
1946	 * because we only calculate enough journal credits for one
1947	 * relink per alloc. */
1948	ac->ac_disable_chain_relink = 1;
1949	for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
1950		if (i == victim)
1951			continue;
1952		if (!cl->cl_recs[i].c_free)
1953			continue;
1954
1955		ac->ac_chain = i;
1956		status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1957					    res, &bits_left);
1958		if (!status) {
1959			hint = ocfs2_group_from_res(res);
1960			break;
1961		}
1962		if (status < 0 && status != -ENOSPC) {
1963			mlog_errno(status);
1964			goto bail;
1965		}
1966	}
1967
1968set_hint:
1969	if (status != -ENOSPC) {
1970		/* If the next search of this group is not likely to
1971		 * yield a suitable extent, then we reset the last
1972		 * group hint so as to not waste a disk read */
1973		if (bits_left < min_bits)
1974			ac->ac_last_group = 0;
1975		else
1976			ac->ac_last_group = hint;
1977	}
1978
1979bail:
1980	if (status)
1981		mlog_errno(status);
1982	return status;
1983}
1984
1985int ocfs2_claim_metadata(handle_t *handle,
1986			 struct ocfs2_alloc_context *ac,
1987			 u32 bits_wanted,
1988			 u64 *suballoc_loc,
1989			 u16 *suballoc_bit_start,
1990			 unsigned int *num_bits,
1991			 u64 *blkno_start)
1992{
1993	int status;
1994	struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
1995
1996	BUG_ON(!ac);
1997	BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
1998	BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
1999
2000	status = ocfs2_claim_suballoc_bits(ac,
2001					   handle,
2002					   bits_wanted,
2003					   1,
2004					   &res);
2005	if (status < 0) {
2006		mlog_errno(status);
2007		goto bail;
2008	}
2009	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2010
2011	*suballoc_loc = res.sr_bg_blkno;
2012	*suballoc_bit_start = res.sr_bit_offset;
2013	*blkno_start = res.sr_blkno;
2014	ac->ac_bits_given += res.sr_bits;
2015	*num_bits = res.sr_bits;
2016	status = 0;
2017bail:
2018	if (status)
2019		mlog_errno(status);
2020	return status;
2021}
2022
2023static void ocfs2_init_inode_ac_group(struct inode *dir,
2024				      struct buffer_head *parent_di_bh,
2025				      struct ocfs2_alloc_context *ac)
2026{
2027	struct ocfs2_dinode *di = (struct ocfs2_dinode *)parent_di_bh->b_data;
2028	/*
2029	 * Try to allocate inodes from some specific group.
2030	 *
2031	 * If the parent dir has recorded the last group used in allocation,
2032	 * cool, use it. Otherwise if we try to allocate new inode from the
2033	 * same slot the parent dir belongs to, use the same chunk.
2034	 *
2035	 * We are very careful here to avoid the mistake of setting
2036	 * ac_last_group to a group descriptor from a different (unlocked) slot.
2037	 */
2038	if (OCFS2_I(dir)->ip_last_used_group &&
2039	    OCFS2_I(dir)->ip_last_used_slot == ac->ac_alloc_slot)
2040		ac->ac_last_group = OCFS2_I(dir)->ip_last_used_group;
2041	else if (le16_to_cpu(di->i_suballoc_slot) == ac->ac_alloc_slot) {
2042		if (di->i_suballoc_loc)
2043			ac->ac_last_group = le64_to_cpu(di->i_suballoc_loc);
2044		else
2045			ac->ac_last_group = ocfs2_which_suballoc_group(
2046					le64_to_cpu(di->i_blkno),
2047					le16_to_cpu(di->i_suballoc_bit));
2048	}
2049}
2050
2051static inline void ocfs2_save_inode_ac_group(struct inode *dir,
2052					     struct ocfs2_alloc_context *ac)
2053{
2054	OCFS2_I(dir)->ip_last_used_group = ac->ac_last_group;
2055	OCFS2_I(dir)->ip_last_used_slot = ac->ac_alloc_slot;
2056}
2057
2058int ocfs2_find_new_inode_loc(struct inode *dir,
2059			     struct buffer_head *parent_fe_bh,
2060			     struct ocfs2_alloc_context *ac,
2061			     u64 *fe_blkno)
2062{
2063	int ret;
2064	handle_t *handle = NULL;
2065	struct ocfs2_suballoc_result *res;
2066
2067	BUG_ON(!ac);
2068	BUG_ON(ac->ac_bits_given != 0);
2069	BUG_ON(ac->ac_bits_wanted != 1);
2070	BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2071
2072	res = kzalloc(sizeof(*res), GFP_NOFS);
2073	if (res == NULL) {
2074		ret = -ENOMEM;
2075		mlog_errno(ret);
2076		goto out;
2077	}
2078
2079	ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2080
2081	/*
2082	 * The handle started here is for chain relink. Alternatively,
2083	 * we could just disable relink for these calls.
2084	 */
2085	handle = ocfs2_start_trans(OCFS2_SB(dir->i_sb), OCFS2_SUBALLOC_ALLOC);
2086	if (IS_ERR(handle)) {
2087		ret = PTR_ERR(handle);
2088		handle = NULL;
2089		mlog_errno(ret);
2090		goto out;
2091	}
2092
2093	/*
2094	 * This will instruct ocfs2_claim_suballoc_bits and
2095	 * ocfs2_search_one_group to search but save actual allocation
2096	 * for later.
2097	 */
2098	ac->ac_find_loc_only = 1;
2099
2100	ret = ocfs2_claim_suballoc_bits(ac, handle, 1, 1, res);
2101	if (ret < 0) {
2102		mlog_errno(ret);
2103		goto out;
2104	}
2105
2106	ac->ac_find_loc_priv = res;
2107	*fe_blkno = res->sr_blkno;
2108	ocfs2_update_inode_fsync_trans(handle, dir, 0);
2109out:
2110	if (handle)
2111		ocfs2_commit_trans(OCFS2_SB(dir->i_sb), handle);
2112
2113	if (ret)
2114		kfree(res);
2115
2116	return ret;
2117}
2118
2119int ocfs2_claim_new_inode_at_loc(handle_t *handle,
2120				 struct inode *dir,
2121				 struct ocfs2_alloc_context *ac,
2122				 u64 *suballoc_loc,
2123				 u16 *suballoc_bit,
2124				 u64 di_blkno)
2125{
2126	int ret;
2127	u16 chain;
2128	struct ocfs2_suballoc_result *res = ac->ac_find_loc_priv;
2129	struct buffer_head *bg_bh = NULL;
2130	struct ocfs2_group_desc *bg;
2131	struct ocfs2_dinode *di = (struct ocfs2_dinode *) ac->ac_bh->b_data;
2132
2133	/*
2134	 * Since di_blkno is being passed back in, we check for any
2135	 * inconsistencies which may have happened between
2136	 * calls. These are code bugs as di_blkno is not expected to
2137	 * change once returned from ocfs2_find_new_inode_loc()
2138	 */
2139	BUG_ON(res->sr_blkno != di_blkno);
2140
2141	ret = ocfs2_read_group_descriptor(ac->ac_inode, di,
2142					  res->sr_bg_stable_blkno, &bg_bh);
2143	if (ret) {
2144		mlog_errno(ret);
2145		goto out;
2146	}
2147
2148	bg = (struct ocfs2_group_desc *) bg_bh->b_data;
2149	chain = le16_to_cpu(bg->bg_chain);
2150
2151	ret = ocfs2_alloc_dinode_update_counts(ac->ac_inode, handle,
2152					       ac->ac_bh, res->sr_bits,
2153					       chain);
2154	if (ret) {
2155		mlog_errno(ret);
2156		goto out;
2157	}
2158
2159	ret = ocfs2_block_group_set_bits(handle,
2160					 ac->ac_inode,
2161					 bg,
2162					 bg_bh,
2163					 res->sr_bit_offset,
2164					 res->sr_bits);
2165	if (ret < 0) {
2166		ocfs2_rollback_alloc_dinode_counts(ac->ac_inode,
2167					       ac->ac_bh, res->sr_bits, chain);
2168		mlog_errno(ret);
2169		goto out;
2170	}
2171
2172	trace_ocfs2_claim_new_inode_at_loc((unsigned long long)di_blkno,
2173					   res->sr_bits);
2174
2175	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2176
2177	BUG_ON(res->sr_bits != 1);
2178
2179	*suballoc_loc = res->sr_bg_blkno;
2180	*suballoc_bit = res->sr_bit_offset;
2181	ac->ac_bits_given++;
2182	ocfs2_save_inode_ac_group(dir, ac);
2183
2184out:
2185	brelse(bg_bh);
2186
2187	return ret;
2188}
2189
2190int ocfs2_claim_new_inode(handle_t *handle,
2191			  struct inode *dir,
2192			  struct buffer_head *parent_fe_bh,
2193			  struct ocfs2_alloc_context *ac,
2194			  u64 *suballoc_loc,
2195			  u16 *suballoc_bit,
2196			  u64 *fe_blkno)
2197{
2198	int status;
2199	struct ocfs2_suballoc_result res;
2200
2201	BUG_ON(!ac);
2202	BUG_ON(ac->ac_bits_given != 0);
2203	BUG_ON(ac->ac_bits_wanted != 1);
2204	BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2205
2206	ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2207
2208	status = ocfs2_claim_suballoc_bits(ac,
2209					   handle,
2210					   1,
2211					   1,
2212					   &res);
2213	if (status < 0) {
2214		mlog_errno(status);
2215		goto bail;
2216	}
2217	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2218
2219	BUG_ON(res.sr_bits != 1);
2220
2221	*suballoc_loc = res.sr_bg_blkno;
2222	*suballoc_bit = res.sr_bit_offset;
2223	*fe_blkno = res.sr_blkno;
2224	ac->ac_bits_given++;
2225	ocfs2_save_inode_ac_group(dir, ac);
2226	status = 0;
2227bail:
2228	if (status)
2229		mlog_errno(status);
2230	return status;
2231}
2232
2233/* translate a group desc. blkno and it's bitmap offset into
2234 * disk cluster offset. */
2235static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
2236						   u64 bg_blkno,
2237						   u16 bg_bit_off)
2238{
2239	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2240	u32 cluster = 0;
2241
2242	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2243
2244	if (bg_blkno != osb->first_cluster_group_blkno)
2245		cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
2246	cluster += (u32) bg_bit_off;
2247	return cluster;
2248}
2249
2250/* given a cluster offset, calculate which block group it belongs to
2251 * and return that block offset. */
2252u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster)
2253{
2254	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2255	u32 group_no;
2256
2257	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2258
2259	group_no = cluster / osb->bitmap_cpg;
2260	if (!group_no)
2261		return osb->first_cluster_group_blkno;
2262	return ocfs2_clusters_to_blocks(inode->i_sb,
2263					group_no * osb->bitmap_cpg);
2264}
2265
2266/* given the block number of a cluster start, calculate which cluster
2267 * group and descriptor bitmap offset that corresponds to. */
2268static inline void ocfs2_block_to_cluster_group(struct inode *inode,
2269						u64 data_blkno,
2270						u64 *bg_blkno,
2271						u16 *bg_bit_off)
2272{
2273	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2274	u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
2275
2276	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2277
2278	*bg_blkno = ocfs2_which_cluster_group(inode,
2279					      data_cluster);
2280
2281	if (*bg_blkno == osb->first_cluster_group_blkno)
2282		*bg_bit_off = (u16) data_cluster;
2283	else
2284		*bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
2285							     data_blkno - *bg_blkno);
2286}
2287
2288/*
2289 * min_bits - minimum contiguous chunk from this total allocation we
2290 * can handle. set to what we asked for originally for a full
2291 * contig. allocation, set to '1' to indicate we can deal with extents
2292 * of any size.
2293 */
2294int __ocfs2_claim_clusters(handle_t *handle,
2295			   struct ocfs2_alloc_context *ac,
2296			   u32 min_clusters,
2297			   u32 max_clusters,
2298			   u32 *cluster_start,
2299			   u32 *num_clusters)
2300{
2301	int status;
2302	unsigned int bits_wanted = max_clusters;
2303	struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
2304	struct ocfs2_super *osb = OCFS2_SB(ac->ac_inode->i_sb);
2305
2306	BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
2307
2308	BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
2309	       && ac->ac_which != OCFS2_AC_USE_MAIN);
2310
2311	if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
2312		WARN_ON(min_clusters > 1);
2313
2314		status = ocfs2_claim_local_alloc_bits(osb,
2315						      handle,
2316						      ac,
2317						      bits_wanted,
2318						      cluster_start,
2319						      num_clusters);
2320		if (!status)
2321			atomic_inc(&osb->alloc_stats.local_data);
2322	} else {
2323		if (min_clusters > (osb->bitmap_cpg - 1)) {
2324			/* The only paths asking for contiguousness
2325			 * should know about this already. */
2326			mlog(ML_ERROR, "minimum allocation requested %u exceeds "
2327			     "group bitmap size %u!\n", min_clusters,
2328			     osb->bitmap_cpg);
2329			status = -ENOSPC;
2330			goto bail;
2331		}
2332		/* clamp the current request down to a realistic size. */
2333		if (bits_wanted > (osb->bitmap_cpg - 1))
2334			bits_wanted = osb->bitmap_cpg - 1;
2335
2336		status = ocfs2_claim_suballoc_bits(ac,
2337						   handle,
2338						   bits_wanted,
2339						   min_clusters,
2340						   &res);
2341		if (!status) {
2342			BUG_ON(res.sr_blkno); /* cluster alloc can't set */
2343			*cluster_start =
2344				ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
2345								 res.sr_bg_blkno,
2346								 res.sr_bit_offset);
2347			atomic_inc(&osb->alloc_stats.bitmap_data);
2348			*num_clusters = res.sr_bits;
2349		}
2350	}
2351	if (status < 0) {
2352		if (status != -ENOSPC)
2353			mlog_errno(status);
2354		goto bail;
2355	}
2356
2357	ac->ac_bits_given += *num_clusters;
2358
2359bail:
2360	if (status)
2361		mlog_errno(status);
2362	return status;
2363}
2364
2365int ocfs2_claim_clusters(handle_t *handle,
2366			 struct ocfs2_alloc_context *ac,
2367			 u32 min_clusters,
2368			 u32 *cluster_start,
2369			 u32 *num_clusters)
2370{
2371	unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
2372
2373	return __ocfs2_claim_clusters(handle, ac, min_clusters,
2374				      bits_wanted, cluster_start, num_clusters);
2375}
2376
2377static int ocfs2_block_group_clear_bits(handle_t *handle,
2378					struct inode *alloc_inode,
2379					struct ocfs2_group_desc *bg,
2380					struct buffer_head *group_bh,
2381					unsigned int bit_off,
2382					unsigned int num_bits,
2383					void (*undo_fn)(unsigned int bit,
2384							unsigned long *bmap))
2385{
2386	int status;
2387	unsigned int tmp;
2388	struct ocfs2_group_desc *undo_bg = NULL;
2389	struct journal_head *jh;
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	jh = bh2jh(group_bh);
2409	if (undo_fn) {
2410		spin_lock(&jh->b_state_lock);
2411		undo_bg = (struct ocfs2_group_desc *) jh->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			spin_unlock(&jh->b_state_lock);
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		spin_unlock(&jh->b_state_lock);
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	return status;
2510}
2511
2512int ocfs2_free_suballoc_bits(handle_t *handle,
2513			     struct inode *alloc_inode,
2514			     struct buffer_head *alloc_bh,
2515			     unsigned int start_bit,
2516			     u64 bg_blkno,
2517			     unsigned int count)
2518{
2519	return _ocfs2_free_suballoc_bits(handle, alloc_inode, alloc_bh,
2520					 start_bit, bg_blkno, count, NULL);
2521}
2522
2523int ocfs2_free_dinode(handle_t *handle,
2524		      struct inode *inode_alloc_inode,
2525		      struct buffer_head *inode_alloc_bh,
2526		      struct ocfs2_dinode *di)
2527{
2528	u64 blk = le64_to_cpu(di->i_blkno);
2529	u16 bit = le16_to_cpu(di->i_suballoc_bit);
2530	u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
2531
2532	if (di->i_suballoc_loc)
2533		bg_blkno = le64_to_cpu(di->i_suballoc_loc);
2534	return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
2535					inode_alloc_bh, bit, bg_blkno, 1);
2536}
2537
2538static int _ocfs2_free_clusters(handle_t *handle,
2539				struct inode *bitmap_inode,
2540				struct buffer_head *bitmap_bh,
2541				u64 start_blk,
2542				unsigned int num_clusters,
2543				void (*undo_fn)(unsigned int bit,
2544						unsigned long *bitmap))
2545{
2546	int status;
2547	u16 bg_start_bit;
2548	u64 bg_blkno;
 
2549
2550	/* You can't ever have a contiguous set of clusters
2551	 * bigger than a block group bitmap so we never have to worry
2552	 * about looping on them.
2553	 * This is expensive. We can safely remove once this stuff has
2554	 * gotten tested really well. */
2555	BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb,
2556				ocfs2_blocks_to_clusters(bitmap_inode->i_sb,
2557							 start_blk)));
2558
 
2559
2560	ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
2561				     &bg_start_bit);
2562
2563	trace_ocfs2_free_clusters((unsigned long long)bg_blkno,
2564			(unsigned long long)start_blk,
2565			bg_start_bit, num_clusters);
2566
2567	status = _ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
2568					   bg_start_bit, bg_blkno,
2569					   num_clusters, undo_fn);
2570	if (status < 0) {
2571		mlog_errno(status);
2572		goto out;
2573	}
2574
2575	ocfs2_local_alloc_seen_free_bits(OCFS2_SB(bitmap_inode->i_sb),
2576					 num_clusters);
2577
2578out:
 
 
2579	return status;
2580}
2581
2582int ocfs2_free_clusters(handle_t *handle,
2583			struct inode *bitmap_inode,
2584			struct buffer_head *bitmap_bh,
2585			u64 start_blk,
2586			unsigned int num_clusters)
2587{
2588	return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2589				    start_blk, num_clusters,
2590				    _ocfs2_set_bit);
2591}
2592
2593/*
2594 * Give never-used clusters back to the global bitmap.  We don't need
2595 * to protect these bits in the undo buffer.
2596 */
2597int ocfs2_release_clusters(handle_t *handle,
2598			   struct inode *bitmap_inode,
2599			   struct buffer_head *bitmap_bh,
2600			   u64 start_blk,
2601			   unsigned int num_clusters)
2602{
2603	return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2604				    start_blk, num_clusters,
2605				    _ocfs2_clear_bit);
2606}
2607
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2608/*
2609 * For a given allocation, determine which allocators will need to be
2610 * accessed, and lock them, reserving the appropriate number of bits.
2611 *
2612 * Sparse file systems call this from ocfs2_write_begin_nolock()
2613 * and ocfs2_allocate_unwritten_extents().
2614 *
2615 * File systems which don't support holes call this from
2616 * ocfs2_extend_allocation().
2617 */
2618int ocfs2_lock_allocators(struct inode *inode,
2619			  struct ocfs2_extent_tree *et,
2620			  u32 clusters_to_add, u32 extents_to_split,
2621			  struct ocfs2_alloc_context **data_ac,
2622			  struct ocfs2_alloc_context **meta_ac)
2623{
2624	int ret = 0, num_free_extents;
2625	unsigned int max_recs_needed = clusters_to_add + 2 * extents_to_split;
2626	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2627
2628	*meta_ac = NULL;
2629	if (data_ac)
2630		*data_ac = NULL;
2631
2632	BUG_ON(clusters_to_add != 0 && data_ac == NULL);
2633
2634	num_free_extents = ocfs2_num_free_extents(et);
2635	if (num_free_extents < 0) {
2636		ret = num_free_extents;
2637		mlog_errno(ret);
2638		goto out;
2639	}
2640
2641	/*
2642	 * Sparse allocation file systems need to be more conservative
2643	 * with reserving room for expansion - the actual allocation
2644	 * happens while we've got a journal handle open so re-taking
2645	 * a cluster lock (because we ran out of room for another
2646	 * extent) will violate ordering rules.
2647	 *
2648	 * Most of the time we'll only be seeing this 1 cluster at a time
2649	 * anyway.
2650	 *
2651	 * Always lock for any unwritten extents - we might want to
2652	 * add blocks during a split.
2653	 */
2654	if (!num_free_extents ||
2655	    (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed)) {
2656		ret = ocfs2_reserve_new_metadata(osb, et->et_root_el, meta_ac);
2657		if (ret < 0) {
2658			if (ret != -ENOSPC)
2659				mlog_errno(ret);
2660			goto out;
2661		}
2662	}
2663
2664	if (clusters_to_add == 0)
2665		goto out;
2666
2667	ret = ocfs2_reserve_clusters(osb, clusters_to_add, data_ac);
2668	if (ret < 0) {
2669		if (ret != -ENOSPC)
2670			mlog_errno(ret);
2671		goto out;
2672	}
2673
2674out:
2675	if (ret) {
2676		if (*meta_ac) {
2677			ocfs2_free_alloc_context(*meta_ac);
2678			*meta_ac = NULL;
2679		}
2680
2681		/*
2682		 * We cannot have an error and a non null *data_ac.
2683		 */
2684	}
2685
2686	return ret;
2687}
2688
2689/*
2690 * Read the inode specified by blkno to get suballoc_slot and
2691 * suballoc_bit.
2692 */
2693static int ocfs2_get_suballoc_slot_bit(struct ocfs2_super *osb, u64 blkno,
2694				       u16 *suballoc_slot, u64 *group_blkno,
2695				       u16 *suballoc_bit)
2696{
2697	int status;
2698	struct buffer_head *inode_bh = NULL;
2699	struct ocfs2_dinode *inode_fe;
2700
2701	trace_ocfs2_get_suballoc_slot_bit((unsigned long long)blkno);
2702
2703	/* dirty read disk */
2704	status = ocfs2_read_blocks_sync(osb, blkno, 1, &inode_bh);
2705	if (status < 0) {
2706		mlog(ML_ERROR, "read block %llu failed %d\n",
2707		     (unsigned long long)blkno, status);
2708		goto bail;
2709	}
2710
2711	inode_fe = (struct ocfs2_dinode *) inode_bh->b_data;
2712	if (!OCFS2_IS_VALID_DINODE(inode_fe)) {
2713		mlog(ML_ERROR, "invalid inode %llu requested\n",
2714		     (unsigned long long)blkno);
2715		status = -EINVAL;
2716		goto bail;
2717	}
2718
2719	if (le16_to_cpu(inode_fe->i_suballoc_slot) != (u16)OCFS2_INVALID_SLOT &&
2720	    (u32)le16_to_cpu(inode_fe->i_suballoc_slot) > osb->max_slots - 1) {
2721		mlog(ML_ERROR, "inode %llu has invalid suballoc slot %u\n",
2722		     (unsigned long long)blkno,
2723		     (u32)le16_to_cpu(inode_fe->i_suballoc_slot));
2724		status = -EINVAL;
2725		goto bail;
2726	}
2727
2728	if (suballoc_slot)
2729		*suballoc_slot = le16_to_cpu(inode_fe->i_suballoc_slot);
2730	if (suballoc_bit)
2731		*suballoc_bit = le16_to_cpu(inode_fe->i_suballoc_bit);
2732	if (group_blkno)
2733		*group_blkno = le64_to_cpu(inode_fe->i_suballoc_loc);
2734
2735bail:
2736	brelse(inode_bh);
2737
2738	if (status)
2739		mlog_errno(status);
2740	return status;
2741}
2742
2743/*
2744 * test whether bit is SET in allocator bitmap or not.  on success, 0
2745 * is returned and *res is 1 for SET; 0 otherwise.  when fails, errno
2746 * is returned and *res is meaningless.  Call this after you have
2747 * cluster locked against suballoc, or you may get a result based on
2748 * non-up2date contents
2749 */
2750static int ocfs2_test_suballoc_bit(struct ocfs2_super *osb,
2751				   struct inode *suballoc,
2752				   struct buffer_head *alloc_bh,
2753				   u64 group_blkno, u64 blkno,
2754				   u16 bit, int *res)
2755{
2756	struct ocfs2_dinode *alloc_di;
2757	struct ocfs2_group_desc *group;
2758	struct buffer_head *group_bh = NULL;
2759	u64 bg_blkno;
2760	int status;
2761
2762	trace_ocfs2_test_suballoc_bit((unsigned long long)blkno,
2763				      (unsigned int)bit);
2764
2765	alloc_di = (struct ocfs2_dinode *)alloc_bh->b_data;
2766	if ((bit + 1) > ocfs2_bits_per_group(&alloc_di->id2.i_chain)) {
2767		mlog(ML_ERROR, "suballoc bit %u out of range of %u\n",
2768		     (unsigned int)bit,
2769		     ocfs2_bits_per_group(&alloc_di->id2.i_chain));
2770		status = -EINVAL;
2771		goto bail;
2772	}
2773
2774	bg_blkno = group_blkno ? group_blkno :
2775		   ocfs2_which_suballoc_group(blkno, bit);
2776	status = ocfs2_read_group_descriptor(suballoc, alloc_di, bg_blkno,
2777					     &group_bh);
2778	if (status < 0) {
2779		mlog(ML_ERROR, "read group %llu failed %d\n",
2780		     (unsigned long long)bg_blkno, status);
2781		goto bail;
2782	}
2783
2784	group = (struct ocfs2_group_desc *) group_bh->b_data;
2785	*res = ocfs2_test_bit(bit, (unsigned long *)group->bg_bitmap);
2786
2787bail:
2788	brelse(group_bh);
2789
2790	if (status)
2791		mlog_errno(status);
2792	return status;
2793}
2794
2795/*
2796 * Test if the bit representing this inode (blkno) is set in the
2797 * suballocator.
2798 *
2799 * On success, 0 is returned and *res is 1 for SET; 0 otherwise.
2800 *
2801 * In the event of failure, a negative value is returned and *res is
2802 * meaningless.
2803 *
2804 * Callers must make sure to hold nfs_sync_lock to prevent
2805 * ocfs2_delete_inode() on another node from accessing the same
2806 * suballocator concurrently.
2807 */
2808int ocfs2_test_inode_bit(struct ocfs2_super *osb, u64 blkno, int *res)
2809{
2810	int status;
2811	u64 group_blkno = 0;
2812	u16 suballoc_bit = 0, suballoc_slot = 0;
2813	struct inode *inode_alloc_inode;
2814	struct buffer_head *alloc_bh = NULL;
2815
2816	trace_ocfs2_test_inode_bit((unsigned long long)blkno);
2817
2818	status = ocfs2_get_suballoc_slot_bit(osb, blkno, &suballoc_slot,
2819					     &group_blkno, &suballoc_bit);
2820	if (status < 0) {
2821		mlog(ML_ERROR, "get alloc slot and bit failed %d\n", status);
2822		goto bail;
2823	}
2824
2825	if (suballoc_slot == (u16)OCFS2_INVALID_SLOT)
2826		inode_alloc_inode = ocfs2_get_system_file_inode(osb,
2827			GLOBAL_INODE_ALLOC_SYSTEM_INODE, suballoc_slot);
2828	else
2829		inode_alloc_inode = ocfs2_get_system_file_inode(osb,
2830			INODE_ALLOC_SYSTEM_INODE, suballoc_slot);
2831	if (!inode_alloc_inode) {
2832		/* the error code could be inaccurate, but we are not able to
2833		 * get the correct one. */
2834		status = -EINVAL;
2835		mlog(ML_ERROR, "unable to get alloc inode in slot %u\n",
2836		     (u32)suballoc_slot);
2837		goto bail;
2838	}
2839
2840	inode_lock(inode_alloc_inode);
2841	status = ocfs2_inode_lock(inode_alloc_inode, &alloc_bh, 0);
2842	if (status < 0) {
2843		inode_unlock(inode_alloc_inode);
2844		iput(inode_alloc_inode);
2845		mlog(ML_ERROR, "lock on alloc inode on slot %u failed %d\n",
2846		     (u32)suballoc_slot, status);
2847		goto bail;
2848	}
2849
2850	status = ocfs2_test_suballoc_bit(osb, inode_alloc_inode, alloc_bh,
2851					 group_blkno, blkno, suballoc_bit, res);
2852	if (status < 0)
2853		mlog(ML_ERROR, "test suballoc bit failed %d\n", status);
2854
2855	ocfs2_inode_unlock(inode_alloc_inode, 0);
2856	inode_unlock(inode_alloc_inode);
2857
2858	iput(inode_alloc_inode);
2859	brelse(alloc_bh);
2860bail:
2861	if (status)
2862		mlog_errno(status);
2863	return status;
2864}
v4.6
   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		inode_unlock(inode);
 145
 146		iput(inode);
 147		ac->ac_inode = NULL;
 148	}
 149	brelse(ac->ac_bh);
 150	ac->ac_bh = NULL;
 151	ac->ac_resv = NULL;
 152	kfree(ac->ac_find_loc_priv);
 153	ac->ac_find_loc_priv = NULL;
 154}
 155
 156void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
 157{
 158	ocfs2_free_ac_resource(ac);
 159	kfree(ac);
 160}
 161
 162static u32 ocfs2_bits_per_group(struct ocfs2_chain_list *cl)
 163{
 164	return (u32)le16_to_cpu(cl->cl_cpg) * (u32)le16_to_cpu(cl->cl_bpc);
 165}
 166
 167#define do_error(fmt, ...)						\
 168do {									\
 169	if (resize)							\
 170		mlog(ML_ERROR, fmt, ##__VA_ARGS__);			\
 171	else								\
 172		return ocfs2_error(sb, fmt, ##__VA_ARGS__);		\
 173} while (0)
 174
 175static int ocfs2_validate_gd_self(struct super_block *sb,
 176				  struct buffer_head *bh,
 177				  int resize)
 178{
 179	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 180
 181	if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
 182		do_error("Group descriptor #%llu has bad signature %.*s\n",
 183			 (unsigned long long)bh->b_blocknr, 7,
 184			 gd->bg_signature);
 185	}
 186
 187	if (le64_to_cpu(gd->bg_blkno) != bh->b_blocknr) {
 188		do_error("Group descriptor #%llu has an invalid bg_blkno of %llu\n",
 189			 (unsigned long long)bh->b_blocknr,
 190			 (unsigned long long)le64_to_cpu(gd->bg_blkno));
 191	}
 192
 193	if (le32_to_cpu(gd->bg_generation) != OCFS2_SB(sb)->fs_generation) {
 194		do_error("Group descriptor #%llu has an invalid fs_generation of #%u\n",
 195			 (unsigned long long)bh->b_blocknr,
 196			 le32_to_cpu(gd->bg_generation));
 197	}
 198
 199	if (le16_to_cpu(gd->bg_free_bits_count) > le16_to_cpu(gd->bg_bits)) {
 200		do_error("Group descriptor #%llu has bit count %u but claims that %u are free\n",
 201			 (unsigned long long)bh->b_blocknr,
 202			 le16_to_cpu(gd->bg_bits),
 203			 le16_to_cpu(gd->bg_free_bits_count));
 204	}
 205
 206	if (le16_to_cpu(gd->bg_bits) > (8 * le16_to_cpu(gd->bg_size))) {
 207		do_error("Group descriptor #%llu has bit count %u but max bitmap bits of %u\n",
 208			 (unsigned long long)bh->b_blocknr,
 209			 le16_to_cpu(gd->bg_bits),
 210			 8 * le16_to_cpu(gd->bg_size));
 211	}
 212
 213	return 0;
 214}
 215
 216static int ocfs2_validate_gd_parent(struct super_block *sb,
 217				    struct ocfs2_dinode *di,
 218				    struct buffer_head *bh,
 219				    int resize)
 220{
 221	unsigned int max_bits;
 222	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 223
 224	if (di->i_blkno != gd->bg_parent_dinode) {
 225		do_error("Group descriptor #%llu has bad parent pointer (%llu, expected %llu)\n",
 226			 (unsigned long long)bh->b_blocknr,
 227			 (unsigned long long)le64_to_cpu(gd->bg_parent_dinode),
 228			 (unsigned long long)le64_to_cpu(di->i_blkno));
 229	}
 230
 231	max_bits = le16_to_cpu(di->id2.i_chain.cl_cpg) * le16_to_cpu(di->id2.i_chain.cl_bpc);
 232	if (le16_to_cpu(gd->bg_bits) > max_bits) {
 233		do_error("Group descriptor #%llu has bit count of %u\n",
 234			 (unsigned long long)bh->b_blocknr,
 235			 le16_to_cpu(gd->bg_bits));
 236	}
 237
 238	/* In resize, we may meet the case bg_chain == cl_next_free_rec. */
 239	if ((le16_to_cpu(gd->bg_chain) >
 240	     le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) ||
 241	    ((le16_to_cpu(gd->bg_chain) ==
 242	     le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) && !resize)) {
 243		do_error("Group descriptor #%llu has bad chain %u\n",
 244			 (unsigned long long)bh->b_blocknr,
 245			 le16_to_cpu(gd->bg_chain));
 246	}
 247
 248	return 0;
 249}
 250
 251#undef do_error
 252
 253/*
 254 * This version only prints errors.  It does not fail the filesystem, and
 255 * exists only for resize.
 256 */
 257int ocfs2_check_group_descriptor(struct super_block *sb,
 258				 struct ocfs2_dinode *di,
 259				 struct buffer_head *bh)
 260{
 261	int rc;
 262	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 263
 264	BUG_ON(!buffer_uptodate(bh));
 265
 266	/*
 267	 * If the ecc fails, we return the error but otherwise
 268	 * leave the filesystem running.  We know any error is
 269	 * local to this block.
 270	 */
 271	rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
 272	if (rc) {
 273		mlog(ML_ERROR,
 274		     "Checksum failed for group descriptor %llu\n",
 275		     (unsigned long long)bh->b_blocknr);
 276	} else
 277		rc = ocfs2_validate_gd_self(sb, bh, 1);
 278	if (!rc)
 279		rc = ocfs2_validate_gd_parent(sb, di, bh, 1);
 280
 281	return rc;
 282}
 283
 284static int ocfs2_validate_group_descriptor(struct super_block *sb,
 285					   struct buffer_head *bh)
 286{
 287	int rc;
 288	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 289
 290	trace_ocfs2_validate_group_descriptor(
 291					(unsigned long long)bh->b_blocknr);
 292
 293	BUG_ON(!buffer_uptodate(bh));
 294
 295	/*
 296	 * If the ecc fails, we return the error but otherwise
 297	 * leave the filesystem running.  We know any error is
 298	 * local to this block.
 299	 */
 300	rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
 301	if (rc)
 302		return rc;
 303
 304	/*
 305	 * Errors after here are fatal.
 306	 */
 307
 308	return ocfs2_validate_gd_self(sb, bh, 0);
 309}
 310
 311int ocfs2_read_group_descriptor(struct inode *inode, struct ocfs2_dinode *di,
 312				u64 gd_blkno, struct buffer_head **bh)
 313{
 314	int rc;
 315	struct buffer_head *tmp = *bh;
 316
 317	rc = ocfs2_read_block(INODE_CACHE(inode), gd_blkno, &tmp,
 318			      ocfs2_validate_group_descriptor);
 319	if (rc)
 320		goto out;
 321
 322	rc = ocfs2_validate_gd_parent(inode->i_sb, di, tmp, 0);
 323	if (rc) {
 324		brelse(tmp);
 325		goto out;
 326	}
 327
 328	/* If ocfs2_read_block() got us a new bh, pass it up. */
 329	if (!*bh)
 330		*bh = tmp;
 331
 332out:
 333	return rc;
 334}
 335
 336static void ocfs2_bg_discontig_add_extent(struct ocfs2_super *osb,
 337					  struct ocfs2_group_desc *bg,
 338					  struct ocfs2_chain_list *cl,
 339					  u64 p_blkno, unsigned int clusters)
 340{
 341	struct ocfs2_extent_list *el = &bg->bg_list;
 342	struct ocfs2_extent_rec *rec;
 343
 344	BUG_ON(!ocfs2_supports_discontig_bg(osb));
 345	if (!el->l_next_free_rec)
 346		el->l_count = cpu_to_le16(ocfs2_extent_recs_per_gd(osb->sb));
 347	rec = &el->l_recs[le16_to_cpu(el->l_next_free_rec)];
 348	rec->e_blkno = cpu_to_le64(p_blkno);
 349	rec->e_cpos = cpu_to_le32(le16_to_cpu(bg->bg_bits) /
 350				  le16_to_cpu(cl->cl_bpc));
 351	rec->e_leaf_clusters = cpu_to_le16(clusters);
 352	le16_add_cpu(&bg->bg_bits, clusters * le16_to_cpu(cl->cl_bpc));
 353	le16_add_cpu(&bg->bg_free_bits_count,
 354		     clusters * le16_to_cpu(cl->cl_bpc));
 355	le16_add_cpu(&el->l_next_free_rec, 1);
 356}
 357
 358static int ocfs2_block_group_fill(handle_t *handle,
 359				  struct inode *alloc_inode,
 360				  struct buffer_head *bg_bh,
 361				  u64 group_blkno,
 362				  unsigned int group_clusters,
 363				  u16 my_chain,
 364				  struct ocfs2_chain_list *cl)
 365{
 366	int status = 0;
 367	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 368	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 369	struct super_block * sb = alloc_inode->i_sb;
 370
 371	if (((unsigned long long) bg_bh->b_blocknr) != group_blkno) {
 372		status = ocfs2_error(alloc_inode->i_sb,
 373				     "group block (%llu) != b_blocknr (%llu)\n",
 374				     (unsigned long long)group_blkno,
 375				     (unsigned long long) bg_bh->b_blocknr);
 376		goto bail;
 377	}
 378
 379	status = ocfs2_journal_access_gd(handle,
 380					 INODE_CACHE(alloc_inode),
 381					 bg_bh,
 382					 OCFS2_JOURNAL_ACCESS_CREATE);
 383	if (status < 0) {
 384		mlog_errno(status);
 385		goto bail;
 386	}
 387
 388	memset(bg, 0, sb->s_blocksize);
 389	strcpy(bg->bg_signature, OCFS2_GROUP_DESC_SIGNATURE);
 390	bg->bg_generation = cpu_to_le32(OCFS2_SB(sb)->fs_generation);
 391	bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb, 1,
 392						osb->s_feature_incompat));
 393	bg->bg_chain = cpu_to_le16(my_chain);
 394	bg->bg_next_group = cl->cl_recs[my_chain].c_blkno;
 395	bg->bg_parent_dinode = cpu_to_le64(OCFS2_I(alloc_inode)->ip_blkno);
 396	bg->bg_blkno = cpu_to_le64(group_blkno);
 397	if (group_clusters == le16_to_cpu(cl->cl_cpg))
 398		bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
 399	else
 400		ocfs2_bg_discontig_add_extent(osb, bg, cl, group_blkno,
 401					      group_clusters);
 402
 403	/* set the 1st bit in the bitmap to account for the descriptor block */
 404	ocfs2_set_bit(0, (unsigned long *)bg->bg_bitmap);
 405	bg->bg_free_bits_count = cpu_to_le16(le16_to_cpu(bg->bg_bits) - 1);
 406
 407	ocfs2_journal_dirty(handle, bg_bh);
 408
 409	/* There is no need to zero out or otherwise initialize the
 410	 * other blocks in a group - All valid FS metadata in a block
 411	 * group stores the superblock fs_generation value at
 412	 * allocation time. */
 413
 414bail:
 415	if (status)
 416		mlog_errno(status);
 417	return status;
 418}
 419
 420static inline u16 ocfs2_find_smallest_chain(struct ocfs2_chain_list *cl)
 421{
 422	u16 curr, best;
 423
 424	best = curr = 0;
 425	while (curr < le16_to_cpu(cl->cl_count)) {
 426		if (le32_to_cpu(cl->cl_recs[best].c_total) >
 427		    le32_to_cpu(cl->cl_recs[curr].c_total))
 428			best = curr;
 429		curr++;
 430	}
 431	return best;
 432}
 433
 434static struct buffer_head *
 435ocfs2_block_group_alloc_contig(struct ocfs2_super *osb, handle_t *handle,
 436			       struct inode *alloc_inode,
 437			       struct ocfs2_alloc_context *ac,
 438			       struct ocfs2_chain_list *cl)
 439{
 440	int status;
 441	u32 bit_off, num_bits;
 442	u64 bg_blkno;
 443	struct buffer_head *bg_bh;
 444	unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
 445
 446	status = ocfs2_claim_clusters(handle, ac,
 447				      le16_to_cpu(cl->cl_cpg), &bit_off,
 448				      &num_bits);
 449	if (status < 0) {
 450		if (status != -ENOSPC)
 451			mlog_errno(status);
 452		goto bail;
 453	}
 454
 455	/* setup the group */
 456	bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 457	trace_ocfs2_block_group_alloc_contig(
 458	     (unsigned long long)bg_blkno, alloc_rec);
 459
 460	bg_bh = sb_getblk(osb->sb, bg_blkno);
 461	if (!bg_bh) {
 462		status = -ENOMEM;
 463		mlog_errno(status);
 464		goto bail;
 465	}
 466	ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
 467
 468	status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
 469					bg_blkno, num_bits, alloc_rec, cl);
 470	if (status < 0) {
 471		brelse(bg_bh);
 472		mlog_errno(status);
 473	}
 474
 475bail:
 476	return status ? ERR_PTR(status) : bg_bh;
 477}
 478
 479static int ocfs2_block_group_claim_bits(struct ocfs2_super *osb,
 480					handle_t *handle,
 481					struct ocfs2_alloc_context *ac,
 482					unsigned int min_bits,
 483					u32 *bit_off, u32 *num_bits)
 484{
 485	int status = 0;
 486
 487	while (min_bits) {
 488		status = ocfs2_claim_clusters(handle, ac, min_bits,
 489					      bit_off, num_bits);
 490		if (status != -ENOSPC)
 491			break;
 492
 493		min_bits >>= 1;
 494	}
 495
 496	return status;
 497}
 498
 499static int ocfs2_block_group_grow_discontig(handle_t *handle,
 500					    struct inode *alloc_inode,
 501					    struct buffer_head *bg_bh,
 502					    struct ocfs2_alloc_context *ac,
 503					    struct ocfs2_chain_list *cl,
 504					    unsigned int min_bits)
 505{
 506	int status;
 507	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 508	struct ocfs2_group_desc *bg =
 509		(struct ocfs2_group_desc *)bg_bh->b_data;
 510	unsigned int needed = le16_to_cpu(cl->cl_cpg) -
 511			 le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
 512	u32 p_cpos, clusters;
 513	u64 p_blkno;
 514	struct ocfs2_extent_list *el = &bg->bg_list;
 515
 516	status = ocfs2_journal_access_gd(handle,
 517					 INODE_CACHE(alloc_inode),
 518					 bg_bh,
 519					 OCFS2_JOURNAL_ACCESS_CREATE);
 520	if (status < 0) {
 521		mlog_errno(status);
 522		goto bail;
 523	}
 524
 525	while ((needed > 0) && (le16_to_cpu(el->l_next_free_rec) <
 526				le16_to_cpu(el->l_count))) {
 527		if (min_bits > needed)
 528			min_bits = needed;
 529		status = ocfs2_block_group_claim_bits(osb, handle, ac,
 530						      min_bits, &p_cpos,
 531						      &clusters);
 532		if (status < 0) {
 533			if (status != -ENOSPC)
 534				mlog_errno(status);
 535			goto bail;
 536		}
 537		p_blkno = ocfs2_clusters_to_blocks(osb->sb, p_cpos);
 538		ocfs2_bg_discontig_add_extent(osb, bg, cl, p_blkno,
 539					      clusters);
 540
 541		min_bits = clusters;
 542		needed = le16_to_cpu(cl->cl_cpg) -
 543			 le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
 544	}
 545
 546	if (needed > 0) {
 547		/*
 548		 * We have used up all the extent rec but can't fill up
 549		 * the cpg. So bail out.
 550		 */
 551		status = -ENOSPC;
 552		goto bail;
 553	}
 554
 555	ocfs2_journal_dirty(handle, bg_bh);
 556
 557bail:
 558	return status;
 559}
 560
 561static void ocfs2_bg_alloc_cleanup(handle_t *handle,
 562				   struct ocfs2_alloc_context *cluster_ac,
 563				   struct inode *alloc_inode,
 564				   struct buffer_head *bg_bh)
 565{
 566	int i, ret;
 567	struct ocfs2_group_desc *bg;
 568	struct ocfs2_extent_list *el;
 569	struct ocfs2_extent_rec *rec;
 570
 571	if (!bg_bh)
 572		return;
 573
 574	bg = (struct ocfs2_group_desc *)bg_bh->b_data;
 575	el = &bg->bg_list;
 576	for (i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
 577		rec = &el->l_recs[i];
 578		ret = ocfs2_free_clusters(handle, cluster_ac->ac_inode,
 579					  cluster_ac->ac_bh,
 580					  le64_to_cpu(rec->e_blkno),
 581					  le16_to_cpu(rec->e_leaf_clusters));
 582		if (ret)
 583			mlog_errno(ret);
 584		/* Try all the clusters to free */
 585	}
 586
 587	ocfs2_remove_from_cache(INODE_CACHE(alloc_inode), bg_bh);
 588	brelse(bg_bh);
 589}
 590
 591static struct buffer_head *
 592ocfs2_block_group_alloc_discontig(handle_t *handle,
 593				  struct inode *alloc_inode,
 594				  struct ocfs2_alloc_context *ac,
 595				  struct ocfs2_chain_list *cl)
 596{
 597	int status;
 598	u32 bit_off, num_bits;
 599	u64 bg_blkno;
 600	unsigned int min_bits = le16_to_cpu(cl->cl_cpg) >> 1;
 601	struct buffer_head *bg_bh = NULL;
 602	unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
 603	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 604
 605	if (!ocfs2_supports_discontig_bg(osb)) {
 606		status = -ENOSPC;
 607		goto bail;
 608	}
 609
 610	status = ocfs2_extend_trans(handle,
 611				    ocfs2_calc_bg_discontig_credits(osb->sb));
 612	if (status) {
 613		mlog_errno(status);
 614		goto bail;
 615	}
 616
 617	/*
 618	 * We're going to be grabbing from multiple cluster groups.
 619	 * We don't have enough credits to relink them all, and the
 620	 * cluster groups will be staying in cache for the duration of
 621	 * this operation.
 622	 */
 623	ac->ac_disable_chain_relink = 1;
 624
 625	/* Claim the first region */
 626	status = ocfs2_block_group_claim_bits(osb, handle, ac, min_bits,
 627					      &bit_off, &num_bits);
 628	if (status < 0) {
 629		if (status != -ENOSPC)
 630			mlog_errno(status);
 631		goto bail;
 632	}
 633	min_bits = num_bits;
 634
 635	/* setup the group */
 636	bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 637	trace_ocfs2_block_group_alloc_discontig(
 638				(unsigned long long)bg_blkno, alloc_rec);
 639
 640	bg_bh = sb_getblk(osb->sb, bg_blkno);
 641	if (!bg_bh) {
 642		status = -ENOMEM;
 643		mlog_errno(status);
 644		goto bail;
 645	}
 646	ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
 647
 648	status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
 649					bg_blkno, num_bits, alloc_rec, cl);
 650	if (status < 0) {
 651		mlog_errno(status);
 652		goto bail;
 653	}
 654
 655	status = ocfs2_block_group_grow_discontig(handle, alloc_inode,
 656						  bg_bh, ac, cl, min_bits);
 657	if (status)
 658		mlog_errno(status);
 659
 660bail:
 661	if (status)
 662		ocfs2_bg_alloc_cleanup(handle, ac, alloc_inode, bg_bh);
 663	return status ? ERR_PTR(status) : bg_bh;
 664}
 665
 666/*
 667 * We expect the block group allocator to already be locked.
 668 */
 669static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
 670				   struct inode *alloc_inode,
 671				   struct buffer_head *bh,
 672				   u64 max_block,
 673				   u64 *last_alloc_group,
 674				   int flags)
 675{
 676	int status, credits;
 677	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) bh->b_data;
 678	struct ocfs2_chain_list *cl;
 679	struct ocfs2_alloc_context *ac = NULL;
 680	handle_t *handle = NULL;
 681	u16 alloc_rec;
 682	struct buffer_head *bg_bh = NULL;
 683	struct ocfs2_group_desc *bg;
 684
 685	BUG_ON(ocfs2_is_cluster_bitmap(alloc_inode));
 686
 687	cl = &fe->id2.i_chain;
 688	status = ocfs2_reserve_clusters_with_limit(osb,
 689						   le16_to_cpu(cl->cl_cpg),
 690						   max_block, flags, &ac);
 691	if (status < 0) {
 692		if (status != -ENOSPC)
 693			mlog_errno(status);
 694		goto bail;
 695	}
 696
 697	credits = ocfs2_calc_group_alloc_credits(osb->sb,
 698						 le16_to_cpu(cl->cl_cpg));
 699	handle = ocfs2_start_trans(osb, credits);
 700	if (IS_ERR(handle)) {
 701		status = PTR_ERR(handle);
 702		handle = NULL;
 703		mlog_errno(status);
 704		goto bail;
 705	}
 706
 707	if (last_alloc_group && *last_alloc_group != 0) {
 708		trace_ocfs2_block_group_alloc(
 709				(unsigned long long)*last_alloc_group);
 710		ac->ac_last_group = *last_alloc_group;
 711	}
 712
 713	bg_bh = ocfs2_block_group_alloc_contig(osb, handle, alloc_inode,
 714					       ac, cl);
 715	if (IS_ERR(bg_bh) && (PTR_ERR(bg_bh) == -ENOSPC))
 716		bg_bh = ocfs2_block_group_alloc_discontig(handle,
 717							  alloc_inode,
 718							  ac, cl);
 719	if (IS_ERR(bg_bh)) {
 720		status = PTR_ERR(bg_bh);
 721		bg_bh = NULL;
 722		if (status != -ENOSPC)
 723			mlog_errno(status);
 724		goto bail;
 725	}
 726	bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 727
 728	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
 729					 bh, OCFS2_JOURNAL_ACCESS_WRITE);
 730	if (status < 0) {
 731		mlog_errno(status);
 732		goto bail;
 733	}
 734
 735	alloc_rec = le16_to_cpu(bg->bg_chain);
 736	le32_add_cpu(&cl->cl_recs[alloc_rec].c_free,
 737		     le16_to_cpu(bg->bg_free_bits_count));
 738	le32_add_cpu(&cl->cl_recs[alloc_rec].c_total,
 739		     le16_to_cpu(bg->bg_bits));
 740	cl->cl_recs[alloc_rec].c_blkno = bg->bg_blkno;
 741	if (le16_to_cpu(cl->cl_next_free_rec) < le16_to_cpu(cl->cl_count))
 742		le16_add_cpu(&cl->cl_next_free_rec, 1);
 743
 744	le32_add_cpu(&fe->id1.bitmap1.i_used, le16_to_cpu(bg->bg_bits) -
 745					le16_to_cpu(bg->bg_free_bits_count));
 746	le32_add_cpu(&fe->id1.bitmap1.i_total, le16_to_cpu(bg->bg_bits));
 747	le32_add_cpu(&fe->i_clusters, le16_to_cpu(cl->cl_cpg));
 748
 749	ocfs2_journal_dirty(handle, bh);
 750
 751	spin_lock(&OCFS2_I(alloc_inode)->ip_lock);
 752	OCFS2_I(alloc_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
 753	fe->i_size = cpu_to_le64(ocfs2_clusters_to_bytes(alloc_inode->i_sb,
 754					     le32_to_cpu(fe->i_clusters)));
 755	spin_unlock(&OCFS2_I(alloc_inode)->ip_lock);
 756	i_size_write(alloc_inode, le64_to_cpu(fe->i_size));
 757	alloc_inode->i_blocks = ocfs2_inode_sector_count(alloc_inode);
 758	ocfs2_update_inode_fsync_trans(handle, alloc_inode, 0);
 759
 760	status = 0;
 761
 762	/* save the new last alloc group so that the caller can cache it. */
 763	if (last_alloc_group)
 764		*last_alloc_group = ac->ac_last_group;
 765
 766bail:
 767	if (handle)
 768		ocfs2_commit_trans(osb, handle);
 769
 770	if (ac)
 771		ocfs2_free_alloc_context(ac);
 772
 773	brelse(bg_bh);
 774
 775	if (status)
 776		mlog_errno(status);
 777	return status;
 778}
 779
 780static int ocfs2_reserve_suballoc_bits(struct ocfs2_super *osb,
 781				       struct ocfs2_alloc_context *ac,
 782				       int type,
 783				       u32 slot,
 784				       u64 *last_alloc_group,
 785				       int flags)
 786{
 787	int status;
 788	u32 bits_wanted = ac->ac_bits_wanted;
 789	struct inode *alloc_inode;
 790	struct buffer_head *bh = NULL;
 791	struct ocfs2_dinode *fe;
 792	u32 free_bits;
 793
 794	alloc_inode = ocfs2_get_system_file_inode(osb, type, slot);
 795	if (!alloc_inode) {
 796		mlog_errno(-EINVAL);
 797		return -EINVAL;
 798	}
 799
 800	inode_lock(alloc_inode);
 801
 802	status = ocfs2_inode_lock(alloc_inode, &bh, 1);
 803	if (status < 0) {
 804		inode_unlock(alloc_inode);
 805		iput(alloc_inode);
 806
 807		mlog_errno(status);
 808		return status;
 809	}
 810
 811	ac->ac_inode = alloc_inode;
 812	ac->ac_alloc_slot = slot;
 813
 814	fe = (struct ocfs2_dinode *) bh->b_data;
 815
 816	/* The bh was validated by the inode read inside
 817	 * ocfs2_inode_lock().  Any corruption is a code bug. */
 818	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
 819
 820	if (!(fe->i_flags & cpu_to_le32(OCFS2_CHAIN_FL))) {
 821		status = ocfs2_error(alloc_inode->i_sb,
 822				     "Invalid chain allocator %llu\n",
 823				     (unsigned long long)le64_to_cpu(fe->i_blkno));
 824		goto bail;
 825	}
 826
 827	free_bits = le32_to_cpu(fe->id1.bitmap1.i_total) -
 828		le32_to_cpu(fe->id1.bitmap1.i_used);
 829
 830	if (bits_wanted > free_bits) {
 831		/* cluster bitmap never grows */
 832		if (ocfs2_is_cluster_bitmap(alloc_inode)) {
 833			trace_ocfs2_reserve_suballoc_bits_nospc(bits_wanted,
 834								free_bits);
 835			status = -ENOSPC;
 836			goto bail;
 837		}
 838
 839		if (!(flags & ALLOC_NEW_GROUP)) {
 840			trace_ocfs2_reserve_suballoc_bits_no_new_group(
 841						slot, bits_wanted, free_bits);
 842			status = -ENOSPC;
 843			goto bail;
 844		}
 845
 846		status = ocfs2_block_group_alloc(osb, alloc_inode, bh,
 847						 ac->ac_max_block,
 848						 last_alloc_group, flags);
 849		if (status < 0) {
 850			if (status != -ENOSPC)
 851				mlog_errno(status);
 852			goto bail;
 853		}
 854		atomic_inc(&osb->alloc_stats.bg_extends);
 855
 856		/* You should never ask for this much metadata */
 857		BUG_ON(bits_wanted >
 858		       (le32_to_cpu(fe->id1.bitmap1.i_total)
 859			- le32_to_cpu(fe->id1.bitmap1.i_used)));
 860	}
 861
 862	get_bh(bh);
 863	ac->ac_bh = bh;
 864bail:
 865	brelse(bh);
 866
 867	if (status)
 868		mlog_errno(status);
 869	return status;
 870}
 871
 872static void ocfs2_init_inode_steal_slot(struct ocfs2_super *osb)
 873{
 874	spin_lock(&osb->osb_lock);
 875	osb->s_inode_steal_slot = OCFS2_INVALID_SLOT;
 876	spin_unlock(&osb->osb_lock);
 877	atomic_set(&osb->s_num_inodes_stolen, 0);
 878}
 879
 880static void ocfs2_init_meta_steal_slot(struct ocfs2_super *osb)
 881{
 882	spin_lock(&osb->osb_lock);
 883	osb->s_meta_steal_slot = OCFS2_INVALID_SLOT;
 884	spin_unlock(&osb->osb_lock);
 885	atomic_set(&osb->s_num_meta_stolen, 0);
 886}
 887
 888void ocfs2_init_steal_slots(struct ocfs2_super *osb)
 889{
 890	ocfs2_init_inode_steal_slot(osb);
 891	ocfs2_init_meta_steal_slot(osb);
 892}
 893
 894static void __ocfs2_set_steal_slot(struct ocfs2_super *osb, int slot, int type)
 895{
 896	spin_lock(&osb->osb_lock);
 897	if (type == INODE_ALLOC_SYSTEM_INODE)
 898		osb->s_inode_steal_slot = slot;
 899	else if (type == EXTENT_ALLOC_SYSTEM_INODE)
 900		osb->s_meta_steal_slot = slot;
 901	spin_unlock(&osb->osb_lock);
 902}
 903
 904static int __ocfs2_get_steal_slot(struct ocfs2_super *osb, int type)
 905{
 906	int slot = OCFS2_INVALID_SLOT;
 907
 908	spin_lock(&osb->osb_lock);
 909	if (type == INODE_ALLOC_SYSTEM_INODE)
 910		slot = osb->s_inode_steal_slot;
 911	else if (type == EXTENT_ALLOC_SYSTEM_INODE)
 912		slot = osb->s_meta_steal_slot;
 913	spin_unlock(&osb->osb_lock);
 914
 915	return slot;
 916}
 917
 918static int ocfs2_get_inode_steal_slot(struct ocfs2_super *osb)
 919{
 920	return __ocfs2_get_steal_slot(osb, INODE_ALLOC_SYSTEM_INODE);
 921}
 922
 923static int ocfs2_get_meta_steal_slot(struct ocfs2_super *osb)
 924{
 925	return __ocfs2_get_steal_slot(osb, EXTENT_ALLOC_SYSTEM_INODE);
 926}
 927
 928static int ocfs2_steal_resource(struct ocfs2_super *osb,
 929				struct ocfs2_alloc_context *ac,
 930				int type)
 931{
 932	int i, status = -ENOSPC;
 933	int slot = __ocfs2_get_steal_slot(osb, type);
 934
 935	/* Start to steal resource from the first slot after ours. */
 936	if (slot == OCFS2_INVALID_SLOT)
 937		slot = osb->slot_num + 1;
 938
 939	for (i = 0; i < osb->max_slots; i++, slot++) {
 940		if (slot == osb->max_slots)
 941			slot = 0;
 942
 943		if (slot == osb->slot_num)
 944			continue;
 945
 946		status = ocfs2_reserve_suballoc_bits(osb, ac,
 947						     type,
 948						     (u32)slot, NULL,
 949						     NOT_ALLOC_NEW_GROUP);
 950		if (status >= 0) {
 951			__ocfs2_set_steal_slot(osb, slot, type);
 952			break;
 953		}
 954
 955		ocfs2_free_ac_resource(ac);
 956	}
 957
 958	return status;
 959}
 960
 961static int ocfs2_steal_inode(struct ocfs2_super *osb,
 962			     struct ocfs2_alloc_context *ac)
 963{
 964	return ocfs2_steal_resource(osb, ac, INODE_ALLOC_SYSTEM_INODE);
 965}
 966
 967static int ocfs2_steal_meta(struct ocfs2_super *osb,
 968			    struct ocfs2_alloc_context *ac)
 969{
 970	return ocfs2_steal_resource(osb, ac, EXTENT_ALLOC_SYSTEM_INODE);
 971}
 972
 973int ocfs2_reserve_new_metadata_blocks(struct ocfs2_super *osb,
 974				      int blocks,
 975				      struct ocfs2_alloc_context **ac)
 976{
 977	int status;
 978	int slot = ocfs2_get_meta_steal_slot(osb);
 979
 980	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 981	if (!(*ac)) {
 982		status = -ENOMEM;
 983		mlog_errno(status);
 984		goto bail;
 985	}
 986
 987	(*ac)->ac_bits_wanted = blocks;
 988	(*ac)->ac_which = OCFS2_AC_USE_META;
 989	(*ac)->ac_group_search = ocfs2_block_group_search;
 990
 991	if (slot != OCFS2_INVALID_SLOT &&
 992		atomic_read(&osb->s_num_meta_stolen) < OCFS2_MAX_TO_STEAL)
 993		goto extent_steal;
 994
 995	atomic_set(&osb->s_num_meta_stolen, 0);
 996	status = ocfs2_reserve_suballoc_bits(osb, (*ac),
 997					     EXTENT_ALLOC_SYSTEM_INODE,
 998					     (u32)osb->slot_num, NULL,
 999					     ALLOC_GROUPS_FROM_GLOBAL|ALLOC_NEW_GROUP);
1000
1001
1002	if (status >= 0) {
1003		status = 0;
1004		if (slot != OCFS2_INVALID_SLOT)
1005			ocfs2_init_meta_steal_slot(osb);
1006		goto bail;
1007	} else if (status < 0 && status != -ENOSPC) {
1008		mlog_errno(status);
1009		goto bail;
1010	}
1011
1012	ocfs2_free_ac_resource(*ac);
1013
1014extent_steal:
1015	status = ocfs2_steal_meta(osb, *ac);
1016	atomic_inc(&osb->s_num_meta_stolen);
1017	if (status < 0) {
1018		if (status != -ENOSPC)
1019			mlog_errno(status);
1020		goto bail;
1021	}
1022
1023	status = 0;
1024bail:
1025	if ((status < 0) && *ac) {
1026		ocfs2_free_alloc_context(*ac);
1027		*ac = NULL;
1028	}
1029
1030	if (status)
1031		mlog_errno(status);
1032	return status;
1033}
1034
1035int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
1036			       struct ocfs2_extent_list *root_el,
1037			       struct ocfs2_alloc_context **ac)
1038{
1039	return ocfs2_reserve_new_metadata_blocks(osb,
1040					ocfs2_extend_meta_needed(root_el),
1041					ac);
1042}
1043
1044int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
1045			    struct ocfs2_alloc_context **ac)
1046{
1047	int status;
1048	int slot = ocfs2_get_inode_steal_slot(osb);
1049	u64 alloc_group;
1050
1051	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1052	if (!(*ac)) {
1053		status = -ENOMEM;
1054		mlog_errno(status);
1055		goto bail;
1056	}
1057
1058	(*ac)->ac_bits_wanted = 1;
1059	(*ac)->ac_which = OCFS2_AC_USE_INODE;
1060
1061	(*ac)->ac_group_search = ocfs2_block_group_search;
1062
1063	/*
1064	 * stat(2) can't handle i_ino > 32bits, so we tell the
1065	 * lower levels not to allocate us a block group past that
1066	 * limit.  The 'inode64' mount option avoids this behavior.
1067	 */
1068	if (!(osb->s_mount_opt & OCFS2_MOUNT_INODE64))
1069		(*ac)->ac_max_block = (u32)~0U;
1070
1071	/*
1072	 * slot is set when we successfully steal inode from other nodes.
1073	 * It is reset in 3 places:
1074	 * 1. when we flush the truncate log
1075	 * 2. when we complete local alloc recovery.
1076	 * 3. when we successfully allocate from our own slot.
1077	 * After it is set, we will go on stealing inodes until we find the
1078	 * need to check our slots to see whether there is some space for us.
1079	 */
1080	if (slot != OCFS2_INVALID_SLOT &&
1081	    atomic_read(&osb->s_num_inodes_stolen) < OCFS2_MAX_TO_STEAL)
1082		goto inode_steal;
1083
1084	atomic_set(&osb->s_num_inodes_stolen, 0);
1085	alloc_group = osb->osb_inode_alloc_group;
1086	status = ocfs2_reserve_suballoc_bits(osb, *ac,
1087					     INODE_ALLOC_SYSTEM_INODE,
1088					     (u32)osb->slot_num,
1089					     &alloc_group,
1090					     ALLOC_NEW_GROUP |
1091					     ALLOC_GROUPS_FROM_GLOBAL);
1092	if (status >= 0) {
1093		status = 0;
1094
1095		spin_lock(&osb->osb_lock);
1096		osb->osb_inode_alloc_group = alloc_group;
1097		spin_unlock(&osb->osb_lock);
1098		trace_ocfs2_reserve_new_inode_new_group(
1099			(unsigned long long)alloc_group);
1100
1101		/*
1102		 * Some inodes must be freed by us, so try to allocate
1103		 * from our own next time.
1104		 */
1105		if (slot != OCFS2_INVALID_SLOT)
1106			ocfs2_init_inode_steal_slot(osb);
1107		goto bail;
1108	} else if (status < 0 && status != -ENOSPC) {
1109		mlog_errno(status);
1110		goto bail;
1111	}
1112
1113	ocfs2_free_ac_resource(*ac);
1114
1115inode_steal:
1116	status = ocfs2_steal_inode(osb, *ac);
1117	atomic_inc(&osb->s_num_inodes_stolen);
1118	if (status < 0) {
1119		if (status != -ENOSPC)
1120			mlog_errno(status);
1121		goto bail;
1122	}
1123
1124	status = 0;
1125bail:
1126	if ((status < 0) && *ac) {
1127		ocfs2_free_alloc_context(*ac);
1128		*ac = NULL;
1129	}
1130
1131	if (status)
1132		mlog_errno(status);
1133	return status;
1134}
1135
1136/* local alloc code has to do the same thing, so rather than do this
1137 * twice.. */
1138int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
1139				      struct ocfs2_alloc_context *ac)
1140{
1141	int status;
1142
1143	ac->ac_which = OCFS2_AC_USE_MAIN;
1144	ac->ac_group_search = ocfs2_cluster_group_search;
1145
1146	status = ocfs2_reserve_suballoc_bits(osb, ac,
1147					     GLOBAL_BITMAP_SYSTEM_INODE,
1148					     OCFS2_INVALID_SLOT, NULL,
1149					     ALLOC_NEW_GROUP);
1150	if (status < 0 && status != -ENOSPC) {
1151		mlog_errno(status);
1152		goto bail;
1153	}
1154
1155bail:
1156	return status;
1157}
1158
1159/* Callers don't need to care which bitmap (local alloc or main) to
1160 * use so we figure it out for them, but unfortunately this clutters
1161 * things a bit. */
1162static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
1163					     u32 bits_wanted, u64 max_block,
1164					     int flags,
1165					     struct ocfs2_alloc_context **ac)
1166{
1167	int status;
 
1168
1169	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1170	if (!(*ac)) {
1171		status = -ENOMEM;
1172		mlog_errno(status);
1173		goto bail;
1174	}
1175
1176	(*ac)->ac_bits_wanted = bits_wanted;
1177	(*ac)->ac_max_block = max_block;
1178
1179	status = -ENOSPC;
1180	if (!(flags & ALLOC_GROUPS_FROM_GLOBAL) &&
1181	    ocfs2_alloc_should_use_local(osb, bits_wanted)) {
1182		status = ocfs2_reserve_local_alloc_bits(osb,
1183							bits_wanted,
1184							*ac);
1185		if ((status < 0) && (status != -ENOSPC)) {
1186			mlog_errno(status);
1187			goto bail;
1188		}
1189	}
1190
1191	if (status == -ENOSPC) {
 
1192		status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1193		if (status < 0) {
1194			if (status != -ENOSPC)
1195				mlog_errno(status);
1196			goto bail;
1197		}
1198	}
1199
1200	status = 0;
1201bail:
1202	if ((status < 0) && *ac) {
1203		ocfs2_free_alloc_context(*ac);
1204		*ac = NULL;
1205	}
1206
1207	if (status)
1208		mlog_errno(status);
1209	return status;
1210}
1211
1212int ocfs2_reserve_clusters(struct ocfs2_super *osb,
1213			   u32 bits_wanted,
1214			   struct ocfs2_alloc_context **ac)
1215{
1216	return ocfs2_reserve_clusters_with_limit(osb, bits_wanted, 0,
1217						 ALLOC_NEW_GROUP, ac);
1218}
1219
1220/*
1221 * More or less lifted from ext3. I'll leave their description below:
1222 *
1223 * "For ext3 allocations, we must not reuse any blocks which are
1224 * allocated in the bitmap buffer's "last committed data" copy.  This
1225 * prevents deletes from freeing up the page for reuse until we have
1226 * committed the delete transaction.
1227 *
1228 * If we didn't do this, then deleting something and reallocating it as
1229 * data would allow the old block to be overwritten before the
1230 * transaction committed (because we force data to disk before commit).
1231 * This would lead to corruption if we crashed between overwriting the
1232 * data and committing the delete.
1233 *
1234 * @@@ We may want to make this allocation behaviour conditional on
1235 * data-writes at some point, and disable it for metadata allocations or
1236 * sync-data inodes."
1237 *
1238 * Note: OCFS2 already does this differently for metadata vs data
1239 * allocations, as those bitmaps are separate and undo access is never
1240 * called on a metadata group descriptor.
1241 */
1242static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
1243					 int nr)
1244{
1245	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 
1246	int ret;
1247
1248	if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
1249		return 0;
1250
1251	if (!buffer_jbd(bg_bh))
 
1252		return 1;
1253
1254	jbd_lock_bh_state(bg_bh);
1255	bg = (struct ocfs2_group_desc *) bh2jh(bg_bh)->b_committed_data;
1256	if (bg)
1257		ret = !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
1258	else
1259		ret = 1;
1260	jbd_unlock_bh_state(bg_bh);
 
1261
1262	return ret;
1263}
1264
1265static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
1266					     struct buffer_head *bg_bh,
1267					     unsigned int bits_wanted,
1268					     unsigned int total_bits,
1269					     struct ocfs2_suballoc_result *res)
1270{
1271	void *bitmap;
1272	u16 best_offset, best_size;
1273	int offset, start, found, status = 0;
1274	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1275
1276	/* Callers got this descriptor from
1277	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1278	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1279
1280	found = start = best_offset = best_size = 0;
1281	bitmap = bg->bg_bitmap;
1282
1283	while((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) != -1) {
1284		if (offset == total_bits)
1285			break;
1286
1287		if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
1288			/* We found a zero, but we can't use it as it
1289			 * hasn't been put to disk yet! */
1290			found = 0;
1291			start = offset + 1;
1292		} else if (offset == start) {
1293			/* we found a zero */
1294			found++;
1295			/* move start to the next bit to test */
1296			start++;
1297		} else {
1298			/* got a zero after some ones */
1299			found = 1;
1300			start = offset + 1;
1301		}
1302		if (found > best_size) {
1303			best_size = found;
1304			best_offset = start - found;
1305		}
1306		/* we got everything we needed */
1307		if (found == bits_wanted) {
1308			/* mlog(0, "Found it all!\n"); */
1309			break;
1310		}
1311	}
1312
1313	if (best_size) {
1314		res->sr_bit_offset = best_offset;
1315		res->sr_bits = best_size;
1316	} else {
1317		status = -ENOSPC;
1318		/* No error log here -- see the comment above
1319		 * ocfs2_test_bg_bit_allocatable */
1320	}
1321
1322	return status;
1323}
1324
1325int ocfs2_block_group_set_bits(handle_t *handle,
1326					     struct inode *alloc_inode,
1327					     struct ocfs2_group_desc *bg,
1328					     struct buffer_head *group_bh,
1329					     unsigned int bit_off,
1330					     unsigned int num_bits)
1331{
1332	int status;
1333	void *bitmap = bg->bg_bitmap;
1334	int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1335
1336	/* All callers get the descriptor via
1337	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1338	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1339	BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
1340
1341	trace_ocfs2_block_group_set_bits(bit_off, num_bits);
1342
1343	if (ocfs2_is_cluster_bitmap(alloc_inode))
1344		journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1345
1346	status = ocfs2_journal_access_gd(handle,
1347					 INODE_CACHE(alloc_inode),
1348					 group_bh,
1349					 journal_type);
1350	if (status < 0) {
1351		mlog_errno(status);
1352		goto bail;
1353	}
1354
1355	le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
1356	if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
1357		return ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit count %u but claims %u are freed. num_bits %d\n",
1358				   (unsigned long long)le64_to_cpu(bg->bg_blkno),
1359				   le16_to_cpu(bg->bg_bits),
1360				   le16_to_cpu(bg->bg_free_bits_count),
1361				   num_bits);
1362	}
1363	while(num_bits--)
1364		ocfs2_set_bit(bit_off++, bitmap);
1365
1366	ocfs2_journal_dirty(handle, group_bh);
1367
1368bail:
1369	return status;
1370}
1371
1372/* find the one with the most empty bits */
1373static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
1374{
1375	u16 curr, best;
1376
1377	BUG_ON(!cl->cl_next_free_rec);
1378
1379	best = curr = 0;
1380	while (curr < le16_to_cpu(cl->cl_next_free_rec)) {
1381		if (le32_to_cpu(cl->cl_recs[curr].c_free) >
1382		    le32_to_cpu(cl->cl_recs[best].c_free))
1383			best = curr;
1384		curr++;
1385	}
1386
1387	BUG_ON(best >= le16_to_cpu(cl->cl_next_free_rec));
1388	return best;
1389}
1390
1391static int ocfs2_relink_block_group(handle_t *handle,
1392				    struct inode *alloc_inode,
1393				    struct buffer_head *fe_bh,
1394				    struct buffer_head *bg_bh,
1395				    struct buffer_head *prev_bg_bh,
1396				    u16 chain)
1397{
1398	int status;
1399	/* there is a really tiny chance the journal calls could fail,
1400	 * but we wouldn't want inconsistent blocks in *any* case. */
1401	u64 bg_ptr, prev_bg_ptr;
1402	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
1403	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1404	struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
1405
1406	/* The caller got these descriptors from
1407	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1408	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1409	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(prev_bg));
1410
1411	trace_ocfs2_relink_block_group(
1412		(unsigned long long)le64_to_cpu(fe->i_blkno), chain,
1413		(unsigned long long)le64_to_cpu(bg->bg_blkno),
1414		(unsigned long long)le64_to_cpu(prev_bg->bg_blkno));
1415
1416	bg_ptr = le64_to_cpu(bg->bg_next_group);
1417	prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
1418
1419	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1420					 prev_bg_bh,
1421					 OCFS2_JOURNAL_ACCESS_WRITE);
1422	if (status < 0)
1423		goto out;
1424
1425	prev_bg->bg_next_group = bg->bg_next_group;
1426	ocfs2_journal_dirty(handle, prev_bg_bh);
1427
1428	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1429					 bg_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1430	if (status < 0)
1431		goto out_rollback_prev_bg;
1432
1433	bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
1434	ocfs2_journal_dirty(handle, bg_bh);
1435
1436	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
1437					 fe_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1438	if (status < 0)
1439		goto out_rollback_bg;
1440
1441	fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
1442	ocfs2_journal_dirty(handle, fe_bh);
1443
1444out:
1445	if (status < 0)
1446		mlog_errno(status);
1447	return status;
1448
1449out_rollback_bg:
1450	bg->bg_next_group = cpu_to_le64(bg_ptr);
1451out_rollback_prev_bg:
1452	prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
1453	goto out;
1454}
1455
1456static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
1457						     u32 wanted)
1458{
1459	return le16_to_cpu(bg->bg_free_bits_count) > wanted;
1460}
1461
1462/* return 0 on success, -ENOSPC to keep searching and any other < 0
1463 * value on error. */
1464static int ocfs2_cluster_group_search(struct inode *inode,
1465				      struct buffer_head *group_bh,
1466				      u32 bits_wanted, u32 min_bits,
1467				      u64 max_block,
1468				      struct ocfs2_suballoc_result *res)
1469{
1470	int search = -ENOSPC;
1471	int ret;
1472	u64 blkoff;
1473	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
1474	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1475	unsigned int max_bits, gd_cluster_off;
1476
1477	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1478
1479	if (gd->bg_free_bits_count) {
1480		max_bits = le16_to_cpu(gd->bg_bits);
1481
1482		/* Tail groups in cluster bitmaps which aren't cpg
1483		 * aligned are prone to partial extension by a failed
1484		 * fs resize. If the file system resize never got to
1485		 * update the dinode cluster count, then we don't want
1486		 * to trust any clusters past it, regardless of what
1487		 * the group descriptor says. */
1488		gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
1489							  le64_to_cpu(gd->bg_blkno));
1490		if ((gd_cluster_off + max_bits) >
1491		    OCFS2_I(inode)->ip_clusters) {
1492			max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
1493			trace_ocfs2_cluster_group_search_wrong_max_bits(
1494				(unsigned long long)le64_to_cpu(gd->bg_blkno),
1495				le16_to_cpu(gd->bg_bits),
1496				OCFS2_I(inode)->ip_clusters, max_bits);
1497		}
1498
1499		ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1500							group_bh, bits_wanted,
1501							max_bits, res);
1502		if (ret)
1503			return ret;
1504
1505		if (max_block) {
1506			blkoff = ocfs2_clusters_to_blocks(inode->i_sb,
1507							  gd_cluster_off +
1508							  res->sr_bit_offset +
1509							  res->sr_bits);
1510			trace_ocfs2_cluster_group_search_max_block(
1511				(unsigned long long)blkoff,
1512				(unsigned long long)max_block);
1513			if (blkoff > max_block)
1514				return -ENOSPC;
1515		}
1516
1517		/* ocfs2_block_group_find_clear_bits() might
1518		 * return success, but we still want to return
1519		 * -ENOSPC unless it found the minimum number
1520		 * of bits. */
1521		if (min_bits <= res->sr_bits)
1522			search = 0; /* success */
1523		else if (res->sr_bits) {
1524			/*
1525			 * Don't show bits which we'll be returning
1526			 * for allocation to the local alloc bitmap.
1527			 */
1528			ocfs2_local_alloc_seen_free_bits(osb, res->sr_bits);
1529		}
1530	}
1531
1532	return search;
1533}
1534
1535static int ocfs2_block_group_search(struct inode *inode,
1536				    struct buffer_head *group_bh,
1537				    u32 bits_wanted, u32 min_bits,
1538				    u64 max_block,
1539				    struct ocfs2_suballoc_result *res)
1540{
1541	int ret = -ENOSPC;
1542	u64 blkoff;
1543	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
1544
1545	BUG_ON(min_bits != 1);
1546	BUG_ON(ocfs2_is_cluster_bitmap(inode));
1547
1548	if (bg->bg_free_bits_count) {
1549		ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1550							group_bh, bits_wanted,
1551							le16_to_cpu(bg->bg_bits),
1552							res);
1553		if (!ret && max_block) {
1554			blkoff = le64_to_cpu(bg->bg_blkno) +
1555				res->sr_bit_offset + res->sr_bits;
1556			trace_ocfs2_block_group_search_max_block(
1557				(unsigned long long)blkoff,
1558				(unsigned long long)max_block);
1559			if (blkoff > max_block)
1560				ret = -ENOSPC;
1561		}
1562	}
1563
1564	return ret;
1565}
1566
1567int ocfs2_alloc_dinode_update_counts(struct inode *inode,
1568				       handle_t *handle,
1569				       struct buffer_head *di_bh,
1570				       u32 num_bits,
1571				       u16 chain)
1572{
1573	int ret;
1574	u32 tmp_used;
1575	struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1576	struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &di->id2.i_chain;
1577
1578	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
1579				      OCFS2_JOURNAL_ACCESS_WRITE);
1580	if (ret < 0) {
1581		mlog_errno(ret);
1582		goto out;
1583	}
1584
1585	tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1586	di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
1587	le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
1588	ocfs2_journal_dirty(handle, di_bh);
1589
1590out:
1591	return ret;
1592}
1593
1594void ocfs2_rollback_alloc_dinode_counts(struct inode *inode,
1595				       struct buffer_head *di_bh,
1596				       u32 num_bits,
1597				       u16 chain)
1598{
1599	u32 tmp_used;
1600	struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1601	struct ocfs2_chain_list *cl;
1602
1603	cl = (struct ocfs2_chain_list *)&di->id2.i_chain;
1604	tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1605	di->id1.bitmap1.i_used = cpu_to_le32(tmp_used - num_bits);
1606	le32_add_cpu(&cl->cl_recs[chain].c_free, num_bits);
1607}
1608
1609static int ocfs2_bg_discontig_fix_by_rec(struct ocfs2_suballoc_result *res,
1610					 struct ocfs2_extent_rec *rec,
1611					 struct ocfs2_chain_list *cl)
1612{
1613	unsigned int bpc = le16_to_cpu(cl->cl_bpc);
1614	unsigned int bitoff = le32_to_cpu(rec->e_cpos) * bpc;
1615	unsigned int bitcount = le16_to_cpu(rec->e_leaf_clusters) * bpc;
1616
1617	if (res->sr_bit_offset < bitoff)
1618		return 0;
1619	if (res->sr_bit_offset >= (bitoff + bitcount))
1620		return 0;
1621	res->sr_blkno = le64_to_cpu(rec->e_blkno) +
1622		(res->sr_bit_offset - bitoff);
1623	if ((res->sr_bit_offset + res->sr_bits) > (bitoff + bitcount))
1624		res->sr_bits = (bitoff + bitcount) - res->sr_bit_offset;
1625	return 1;
1626}
1627
1628static void ocfs2_bg_discontig_fix_result(struct ocfs2_alloc_context *ac,
1629					  struct ocfs2_group_desc *bg,
1630					  struct ocfs2_suballoc_result *res)
1631{
1632	int i;
1633	u64 bg_blkno = res->sr_bg_blkno;  /* Save off */
1634	struct ocfs2_extent_rec *rec;
1635	struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1636	struct ocfs2_chain_list *cl = &di->id2.i_chain;
1637
1638	if (ocfs2_is_cluster_bitmap(ac->ac_inode)) {
1639		res->sr_blkno = 0;
1640		return;
1641	}
1642
1643	res->sr_blkno = res->sr_bg_blkno + res->sr_bit_offset;
1644	res->sr_bg_blkno = 0;  /* Clear it for contig block groups */
1645	if (!ocfs2_supports_discontig_bg(OCFS2_SB(ac->ac_inode->i_sb)) ||
1646	    !bg->bg_list.l_next_free_rec)
1647		return;
1648
1649	for (i = 0; i < le16_to_cpu(bg->bg_list.l_next_free_rec); i++) {
1650		rec = &bg->bg_list.l_recs[i];
1651		if (ocfs2_bg_discontig_fix_by_rec(res, rec, cl)) {
1652			res->sr_bg_blkno = bg_blkno;  /* Restore */
1653			break;
1654		}
1655	}
1656}
1657
1658static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
1659				  handle_t *handle,
1660				  u32 bits_wanted,
1661				  u32 min_bits,
1662				  struct ocfs2_suballoc_result *res,
1663				  u16 *bits_left)
1664{
1665	int ret;
1666	struct buffer_head *group_bh = NULL;
1667	struct ocfs2_group_desc *gd;
1668	struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1669	struct inode *alloc_inode = ac->ac_inode;
1670
1671	ret = ocfs2_read_group_descriptor(alloc_inode, di,
1672					  res->sr_bg_blkno, &group_bh);
1673	if (ret < 0) {
1674		mlog_errno(ret);
1675		return ret;
1676	}
1677
1678	gd = (struct ocfs2_group_desc *) group_bh->b_data;
1679	ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
1680				  ac->ac_max_block, res);
1681	if (ret < 0) {
1682		if (ret != -ENOSPC)
1683			mlog_errno(ret);
1684		goto out;
1685	}
1686
1687	if (!ret)
1688		ocfs2_bg_discontig_fix_result(ac, gd, res);
1689
1690	/*
1691	 * sr_bg_blkno might have been changed by
1692	 * ocfs2_bg_discontig_fix_result
1693	 */
1694	res->sr_bg_stable_blkno = group_bh->b_blocknr;
1695
1696	if (ac->ac_find_loc_only)
1697		goto out_loc_only;
1698
1699	ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
1700					       res->sr_bits,
1701					       le16_to_cpu(gd->bg_chain));
1702	if (ret < 0) {
1703		mlog_errno(ret);
1704		goto out;
1705	}
1706
1707	ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
1708					 res->sr_bit_offset, res->sr_bits);
1709	if (ret < 0) {
1710		ocfs2_rollback_alloc_dinode_counts(alloc_inode, ac->ac_bh,
1711					       res->sr_bits,
1712					       le16_to_cpu(gd->bg_chain));
1713		mlog_errno(ret);
1714	}
1715
1716out_loc_only:
1717	*bits_left = le16_to_cpu(gd->bg_free_bits_count);
1718
1719out:
1720	brelse(group_bh);
1721
1722	return ret;
1723}
1724
1725static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
1726			      handle_t *handle,
1727			      u32 bits_wanted,
1728			      u32 min_bits,
1729			      struct ocfs2_suballoc_result *res,
1730			      u16 *bits_left)
1731{
1732	int status;
1733	u16 chain;
1734	u64 next_group;
1735	struct inode *alloc_inode = ac->ac_inode;
1736	struct buffer_head *group_bh = NULL;
1737	struct buffer_head *prev_group_bh = NULL;
1738	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1739	struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1740	struct ocfs2_group_desc *bg;
1741
1742	chain = ac->ac_chain;
1743	trace_ocfs2_search_chain_begin(
1744		(unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
1745		bits_wanted, chain);
1746
1747	status = ocfs2_read_group_descriptor(alloc_inode, fe,
1748					     le64_to_cpu(cl->cl_recs[chain].c_blkno),
1749					     &group_bh);
1750	if (status < 0) {
1751		mlog_errno(status);
1752		goto bail;
1753	}
1754	bg = (struct ocfs2_group_desc *) group_bh->b_data;
1755
1756	status = -ENOSPC;
1757	/* for now, the chain search is a bit simplistic. We just use
1758	 * the 1st group with any empty bits. */
1759	while ((status = ac->ac_group_search(alloc_inode, group_bh,
1760					     bits_wanted, min_bits,
1761					     ac->ac_max_block,
1762					     res)) == -ENOSPC) {
1763		if (!bg->bg_next_group)
1764			break;
1765
1766		brelse(prev_group_bh);
1767		prev_group_bh = NULL;
1768
1769		next_group = le64_to_cpu(bg->bg_next_group);
1770		prev_group_bh = group_bh;
1771		group_bh = NULL;
1772		status = ocfs2_read_group_descriptor(alloc_inode, fe,
1773						     next_group, &group_bh);
1774		if (status < 0) {
1775			mlog_errno(status);
1776			goto bail;
1777		}
1778		bg = (struct ocfs2_group_desc *) group_bh->b_data;
1779	}
1780	if (status < 0) {
1781		if (status != -ENOSPC)
1782			mlog_errno(status);
1783		goto bail;
1784	}
1785
1786	trace_ocfs2_search_chain_succ(
1787		(unsigned long long)le64_to_cpu(bg->bg_blkno), res->sr_bits);
1788
1789	res->sr_bg_blkno = le64_to_cpu(bg->bg_blkno);
1790
1791	BUG_ON(res->sr_bits == 0);
1792	if (!status)
1793		ocfs2_bg_discontig_fix_result(ac, bg, res);
1794
1795	/*
1796	 * sr_bg_blkno might have been changed by
1797	 * ocfs2_bg_discontig_fix_result
1798	 */
1799	res->sr_bg_stable_blkno = group_bh->b_blocknr;
1800
1801	/*
1802	 * Keep track of previous block descriptor read. When
1803	 * we find a target, if we have read more than X
1804	 * number of descriptors, and the target is reasonably
1805	 * empty, relink him to top of his chain.
1806	 *
1807	 * We've read 0 extra blocks and only send one more to
1808	 * the transaction, yet the next guy to search has a
1809	 * much easier time.
1810	 *
1811	 * Do this *after* figuring out how many bits we're taking out
1812	 * of our target group.
1813	 */
1814	if (!ac->ac_disable_chain_relink &&
1815	    (prev_group_bh) &&
1816	    (ocfs2_block_group_reasonably_empty(bg, res->sr_bits))) {
1817		status = ocfs2_relink_block_group(handle, alloc_inode,
1818						  ac->ac_bh, group_bh,
1819						  prev_group_bh, chain);
1820		if (status < 0) {
1821			mlog_errno(status);
1822			goto bail;
1823		}
1824	}
1825
1826	if (ac->ac_find_loc_only)
1827		goto out_loc_only;
1828
1829	status = ocfs2_alloc_dinode_update_counts(alloc_inode, handle,
1830						  ac->ac_bh, res->sr_bits,
1831						  chain);
1832	if (status) {
1833		mlog_errno(status);
1834		goto bail;
1835	}
1836
1837	status = ocfs2_block_group_set_bits(handle,
1838					    alloc_inode,
1839					    bg,
1840					    group_bh,
1841					    res->sr_bit_offset,
1842					    res->sr_bits);
1843	if (status < 0) {
1844		ocfs2_rollback_alloc_dinode_counts(alloc_inode,
1845					ac->ac_bh, res->sr_bits, chain);
1846		mlog_errno(status);
1847		goto bail;
1848	}
1849
1850	trace_ocfs2_search_chain_end(
1851			(unsigned long long)le64_to_cpu(fe->i_blkno),
1852			res->sr_bits);
1853
1854out_loc_only:
1855	*bits_left = le16_to_cpu(bg->bg_free_bits_count);
1856bail:
1857	brelse(group_bh);
1858	brelse(prev_group_bh);
1859
1860	if (status)
1861		mlog_errno(status);
1862	return status;
1863}
1864
1865/* will give out up to bits_wanted contiguous bits. */
1866static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
1867				     handle_t *handle,
1868				     u32 bits_wanted,
1869				     u32 min_bits,
1870				     struct ocfs2_suballoc_result *res)
1871{
1872	int status;
1873	u16 victim, i;
1874	u16 bits_left = 0;
1875	u64 hint = ac->ac_last_group;
1876	struct ocfs2_chain_list *cl;
1877	struct ocfs2_dinode *fe;
1878
1879	BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1880	BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1881	BUG_ON(!ac->ac_bh);
1882
1883	fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1884
1885	/* The bh was validated by the inode read during
1886	 * ocfs2_reserve_suballoc_bits().  Any corruption is a code bug. */
1887	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
1888
1889	if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1890	    le32_to_cpu(fe->id1.bitmap1.i_total)) {
1891		status = ocfs2_error(ac->ac_inode->i_sb,
1892				     "Chain allocator dinode %llu has %u used bits but only %u total\n",
1893				     (unsigned long long)le64_to_cpu(fe->i_blkno),
1894				     le32_to_cpu(fe->id1.bitmap1.i_used),
1895				     le32_to_cpu(fe->id1.bitmap1.i_total));
1896		goto bail;
1897	}
1898
1899	res->sr_bg_blkno = hint;
1900	if (res->sr_bg_blkno) {
1901		/* Attempt to short-circuit the usual search mechanism
1902		 * by jumping straight to the most recently used
1903		 * allocation group. This helps us maintain some
1904		 * contiguousness across allocations. */
1905		status = ocfs2_search_one_group(ac, handle, bits_wanted,
1906						min_bits, res, &bits_left);
1907		if (!status)
1908			goto set_hint;
1909		if (status < 0 && status != -ENOSPC) {
1910			mlog_errno(status);
1911			goto bail;
1912		}
1913	}
1914
1915	cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1916
1917	victim = ocfs2_find_victim_chain(cl);
1918	ac->ac_chain = victim;
1919
1920	status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1921				    res, &bits_left);
1922	if (!status) {
1923		if (ocfs2_is_cluster_bitmap(ac->ac_inode))
1924			hint = res->sr_bg_blkno;
1925		else
1926			hint = ocfs2_group_from_res(res);
1927		goto set_hint;
1928	}
1929	if (status < 0 && status != -ENOSPC) {
1930		mlog_errno(status);
1931		goto bail;
1932	}
1933
1934	trace_ocfs2_claim_suballoc_bits(victim);
1935
1936	/* If we didn't pick a good victim, then just default to
1937	 * searching each chain in order. Don't allow chain relinking
1938	 * because we only calculate enough journal credits for one
1939	 * relink per alloc. */
1940	ac->ac_disable_chain_relink = 1;
1941	for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
1942		if (i == victim)
1943			continue;
1944		if (!cl->cl_recs[i].c_free)
1945			continue;
1946
1947		ac->ac_chain = i;
1948		status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1949					    res, &bits_left);
1950		if (!status) {
1951			hint = ocfs2_group_from_res(res);
1952			break;
1953		}
1954		if (status < 0 && status != -ENOSPC) {
1955			mlog_errno(status);
1956			goto bail;
1957		}
1958	}
1959
1960set_hint:
1961	if (status != -ENOSPC) {
1962		/* If the next search of this group is not likely to
1963		 * yield a suitable extent, then we reset the last
1964		 * group hint so as to not waste a disk read */
1965		if (bits_left < min_bits)
1966			ac->ac_last_group = 0;
1967		else
1968			ac->ac_last_group = hint;
1969	}
1970
1971bail:
1972	if (status)
1973		mlog_errno(status);
1974	return status;
1975}
1976
1977int ocfs2_claim_metadata(handle_t *handle,
1978			 struct ocfs2_alloc_context *ac,
1979			 u32 bits_wanted,
1980			 u64 *suballoc_loc,
1981			 u16 *suballoc_bit_start,
1982			 unsigned int *num_bits,
1983			 u64 *blkno_start)
1984{
1985	int status;
1986	struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
1987
1988	BUG_ON(!ac);
1989	BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
1990	BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
1991
1992	status = ocfs2_claim_suballoc_bits(ac,
1993					   handle,
1994					   bits_wanted,
1995					   1,
1996					   &res);
1997	if (status < 0) {
1998		mlog_errno(status);
1999		goto bail;
2000	}
2001	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2002
2003	*suballoc_loc = res.sr_bg_blkno;
2004	*suballoc_bit_start = res.sr_bit_offset;
2005	*blkno_start = res.sr_blkno;
2006	ac->ac_bits_given += res.sr_bits;
2007	*num_bits = res.sr_bits;
2008	status = 0;
2009bail:
2010	if (status)
2011		mlog_errno(status);
2012	return status;
2013}
2014
2015static void ocfs2_init_inode_ac_group(struct inode *dir,
2016				      struct buffer_head *parent_di_bh,
2017				      struct ocfs2_alloc_context *ac)
2018{
2019	struct ocfs2_dinode *di = (struct ocfs2_dinode *)parent_di_bh->b_data;
2020	/*
2021	 * Try to allocate inodes from some specific group.
2022	 *
2023	 * If the parent dir has recorded the last group used in allocation,
2024	 * cool, use it. Otherwise if we try to allocate new inode from the
2025	 * same slot the parent dir belongs to, use the same chunk.
2026	 *
2027	 * We are very careful here to avoid the mistake of setting
2028	 * ac_last_group to a group descriptor from a different (unlocked) slot.
2029	 */
2030	if (OCFS2_I(dir)->ip_last_used_group &&
2031	    OCFS2_I(dir)->ip_last_used_slot == ac->ac_alloc_slot)
2032		ac->ac_last_group = OCFS2_I(dir)->ip_last_used_group;
2033	else if (le16_to_cpu(di->i_suballoc_slot) == ac->ac_alloc_slot) {
2034		if (di->i_suballoc_loc)
2035			ac->ac_last_group = le64_to_cpu(di->i_suballoc_loc);
2036		else
2037			ac->ac_last_group = ocfs2_which_suballoc_group(
2038					le64_to_cpu(di->i_blkno),
2039					le16_to_cpu(di->i_suballoc_bit));
2040	}
2041}
2042
2043static inline void ocfs2_save_inode_ac_group(struct inode *dir,
2044					     struct ocfs2_alloc_context *ac)
2045{
2046	OCFS2_I(dir)->ip_last_used_group = ac->ac_last_group;
2047	OCFS2_I(dir)->ip_last_used_slot = ac->ac_alloc_slot;
2048}
2049
2050int ocfs2_find_new_inode_loc(struct inode *dir,
2051			     struct buffer_head *parent_fe_bh,
2052			     struct ocfs2_alloc_context *ac,
2053			     u64 *fe_blkno)
2054{
2055	int ret;
2056	handle_t *handle = NULL;
2057	struct ocfs2_suballoc_result *res;
2058
2059	BUG_ON(!ac);
2060	BUG_ON(ac->ac_bits_given != 0);
2061	BUG_ON(ac->ac_bits_wanted != 1);
2062	BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2063
2064	res = kzalloc(sizeof(*res), GFP_NOFS);
2065	if (res == NULL) {
2066		ret = -ENOMEM;
2067		mlog_errno(ret);
2068		goto out;
2069	}
2070
2071	ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2072
2073	/*
2074	 * The handle started here is for chain relink. Alternatively,
2075	 * we could just disable relink for these calls.
2076	 */
2077	handle = ocfs2_start_trans(OCFS2_SB(dir->i_sb), OCFS2_SUBALLOC_ALLOC);
2078	if (IS_ERR(handle)) {
2079		ret = PTR_ERR(handle);
2080		handle = NULL;
2081		mlog_errno(ret);
2082		goto out;
2083	}
2084
2085	/*
2086	 * This will instruct ocfs2_claim_suballoc_bits and
2087	 * ocfs2_search_one_group to search but save actual allocation
2088	 * for later.
2089	 */
2090	ac->ac_find_loc_only = 1;
2091
2092	ret = ocfs2_claim_suballoc_bits(ac, handle, 1, 1, res);
2093	if (ret < 0) {
2094		mlog_errno(ret);
2095		goto out;
2096	}
2097
2098	ac->ac_find_loc_priv = res;
2099	*fe_blkno = res->sr_blkno;
2100	ocfs2_update_inode_fsync_trans(handle, dir, 0);
2101out:
2102	if (handle)
2103		ocfs2_commit_trans(OCFS2_SB(dir->i_sb), handle);
2104
2105	if (ret)
2106		kfree(res);
2107
2108	return ret;
2109}
2110
2111int ocfs2_claim_new_inode_at_loc(handle_t *handle,
2112				 struct inode *dir,
2113				 struct ocfs2_alloc_context *ac,
2114				 u64 *suballoc_loc,
2115				 u16 *suballoc_bit,
2116				 u64 di_blkno)
2117{
2118	int ret;
2119	u16 chain;
2120	struct ocfs2_suballoc_result *res = ac->ac_find_loc_priv;
2121	struct buffer_head *bg_bh = NULL;
2122	struct ocfs2_group_desc *bg;
2123	struct ocfs2_dinode *di = (struct ocfs2_dinode *) ac->ac_bh->b_data;
2124
2125	/*
2126	 * Since di_blkno is being passed back in, we check for any
2127	 * inconsistencies which may have happened between
2128	 * calls. These are code bugs as di_blkno is not expected to
2129	 * change once returned from ocfs2_find_new_inode_loc()
2130	 */
2131	BUG_ON(res->sr_blkno != di_blkno);
2132
2133	ret = ocfs2_read_group_descriptor(ac->ac_inode, di,
2134					  res->sr_bg_stable_blkno, &bg_bh);
2135	if (ret) {
2136		mlog_errno(ret);
2137		goto out;
2138	}
2139
2140	bg = (struct ocfs2_group_desc *) bg_bh->b_data;
2141	chain = le16_to_cpu(bg->bg_chain);
2142
2143	ret = ocfs2_alloc_dinode_update_counts(ac->ac_inode, handle,
2144					       ac->ac_bh, res->sr_bits,
2145					       chain);
2146	if (ret) {
2147		mlog_errno(ret);
2148		goto out;
2149	}
2150
2151	ret = ocfs2_block_group_set_bits(handle,
2152					 ac->ac_inode,
2153					 bg,
2154					 bg_bh,
2155					 res->sr_bit_offset,
2156					 res->sr_bits);
2157	if (ret < 0) {
2158		ocfs2_rollback_alloc_dinode_counts(ac->ac_inode,
2159					       ac->ac_bh, res->sr_bits, chain);
2160		mlog_errno(ret);
2161		goto out;
2162	}
2163
2164	trace_ocfs2_claim_new_inode_at_loc((unsigned long long)di_blkno,
2165					   res->sr_bits);
2166
2167	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2168
2169	BUG_ON(res->sr_bits != 1);
2170
2171	*suballoc_loc = res->sr_bg_blkno;
2172	*suballoc_bit = res->sr_bit_offset;
2173	ac->ac_bits_given++;
2174	ocfs2_save_inode_ac_group(dir, ac);
2175
2176out:
2177	brelse(bg_bh);
2178
2179	return ret;
2180}
2181
2182int ocfs2_claim_new_inode(handle_t *handle,
2183			  struct inode *dir,
2184			  struct buffer_head *parent_fe_bh,
2185			  struct ocfs2_alloc_context *ac,
2186			  u64 *suballoc_loc,
2187			  u16 *suballoc_bit,
2188			  u64 *fe_blkno)
2189{
2190	int status;
2191	struct ocfs2_suballoc_result res;
2192
2193	BUG_ON(!ac);
2194	BUG_ON(ac->ac_bits_given != 0);
2195	BUG_ON(ac->ac_bits_wanted != 1);
2196	BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2197
2198	ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2199
2200	status = ocfs2_claim_suballoc_bits(ac,
2201					   handle,
2202					   1,
2203					   1,
2204					   &res);
2205	if (status < 0) {
2206		mlog_errno(status);
2207		goto bail;
2208	}
2209	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2210
2211	BUG_ON(res.sr_bits != 1);
2212
2213	*suballoc_loc = res.sr_bg_blkno;
2214	*suballoc_bit = res.sr_bit_offset;
2215	*fe_blkno = res.sr_blkno;
2216	ac->ac_bits_given++;
2217	ocfs2_save_inode_ac_group(dir, ac);
2218	status = 0;
2219bail:
2220	if (status)
2221		mlog_errno(status);
2222	return status;
2223}
2224
2225/* translate a group desc. blkno and it's bitmap offset into
2226 * disk cluster offset. */
2227static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
2228						   u64 bg_blkno,
2229						   u16 bg_bit_off)
2230{
2231	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2232	u32 cluster = 0;
2233
2234	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2235
2236	if (bg_blkno != osb->first_cluster_group_blkno)
2237		cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
2238	cluster += (u32) bg_bit_off;
2239	return cluster;
2240}
2241
2242/* given a cluster offset, calculate which block group it belongs to
2243 * and return that block offset. */
2244u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster)
2245{
2246	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2247	u32 group_no;
2248
2249	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2250
2251	group_no = cluster / osb->bitmap_cpg;
2252	if (!group_no)
2253		return osb->first_cluster_group_blkno;
2254	return ocfs2_clusters_to_blocks(inode->i_sb,
2255					group_no * osb->bitmap_cpg);
2256}
2257
2258/* given the block number of a cluster start, calculate which cluster
2259 * group and descriptor bitmap offset that corresponds to. */
2260static inline void ocfs2_block_to_cluster_group(struct inode *inode,
2261						u64 data_blkno,
2262						u64 *bg_blkno,
2263						u16 *bg_bit_off)
2264{
2265	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2266	u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
2267
2268	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2269
2270	*bg_blkno = ocfs2_which_cluster_group(inode,
2271					      data_cluster);
2272
2273	if (*bg_blkno == osb->first_cluster_group_blkno)
2274		*bg_bit_off = (u16) data_cluster;
2275	else
2276		*bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
2277							     data_blkno - *bg_blkno);
2278}
2279
2280/*
2281 * min_bits - minimum contiguous chunk from this total allocation we
2282 * can handle. set to what we asked for originally for a full
2283 * contig. allocation, set to '1' to indicate we can deal with extents
2284 * of any size.
2285 */
2286int __ocfs2_claim_clusters(handle_t *handle,
2287			   struct ocfs2_alloc_context *ac,
2288			   u32 min_clusters,
2289			   u32 max_clusters,
2290			   u32 *cluster_start,
2291			   u32 *num_clusters)
2292{
2293	int status;
2294	unsigned int bits_wanted = max_clusters;
2295	struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
2296	struct ocfs2_super *osb = OCFS2_SB(ac->ac_inode->i_sb);
2297
2298	BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
2299
2300	BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
2301	       && ac->ac_which != OCFS2_AC_USE_MAIN);
2302
2303	if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
2304		WARN_ON(min_clusters > 1);
2305
2306		status = ocfs2_claim_local_alloc_bits(osb,
2307						      handle,
2308						      ac,
2309						      bits_wanted,
2310						      cluster_start,
2311						      num_clusters);
2312		if (!status)
2313			atomic_inc(&osb->alloc_stats.local_data);
2314	} else {
2315		if (min_clusters > (osb->bitmap_cpg - 1)) {
2316			/* The only paths asking for contiguousness
2317			 * should know about this already. */
2318			mlog(ML_ERROR, "minimum allocation requested %u exceeds "
2319			     "group bitmap size %u!\n", min_clusters,
2320			     osb->bitmap_cpg);
2321			status = -ENOSPC;
2322			goto bail;
2323		}
2324		/* clamp the current request down to a realistic size. */
2325		if (bits_wanted > (osb->bitmap_cpg - 1))
2326			bits_wanted = osb->bitmap_cpg - 1;
2327
2328		status = ocfs2_claim_suballoc_bits(ac,
2329						   handle,
2330						   bits_wanted,
2331						   min_clusters,
2332						   &res);
2333		if (!status) {
2334			BUG_ON(res.sr_blkno); /* cluster alloc can't set */
2335			*cluster_start =
2336				ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
2337								 res.sr_bg_blkno,
2338								 res.sr_bit_offset);
2339			atomic_inc(&osb->alloc_stats.bitmap_data);
2340			*num_clusters = res.sr_bits;
2341		}
2342	}
2343	if (status < 0) {
2344		if (status != -ENOSPC)
2345			mlog_errno(status);
2346		goto bail;
2347	}
2348
2349	ac->ac_bits_given += *num_clusters;
2350
2351bail:
2352	if (status)
2353		mlog_errno(status);
2354	return status;
2355}
2356
2357int ocfs2_claim_clusters(handle_t *handle,
2358			 struct ocfs2_alloc_context *ac,
2359			 u32 min_clusters,
2360			 u32 *cluster_start,
2361			 u32 *num_clusters)
2362{
2363	unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
2364
2365	return __ocfs2_claim_clusters(handle, ac, min_clusters,
2366				      bits_wanted, cluster_start, num_clusters);
2367}
2368
2369static int ocfs2_block_group_clear_bits(handle_t *handle,
2370					struct inode *alloc_inode,
2371					struct ocfs2_group_desc *bg,
2372					struct buffer_head *group_bh,
2373					unsigned int bit_off,
2374					unsigned int num_bits,
2375					void (*undo_fn)(unsigned int bit,
2376							unsigned long *bmap))
2377{
2378	int status;
2379	unsigned int tmp;
2380	struct ocfs2_group_desc *undo_bg = NULL;
 
2381
2382	/* The caller got this descriptor from
2383	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
2384	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
2385
2386	trace_ocfs2_block_group_clear_bits(bit_off, num_bits);
2387
2388	BUG_ON(undo_fn && !ocfs2_is_cluster_bitmap(alloc_inode));
2389	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
2390					 group_bh,
2391					 undo_fn ?
2392					 OCFS2_JOURNAL_ACCESS_UNDO :
2393					 OCFS2_JOURNAL_ACCESS_WRITE);
2394	if (status < 0) {
2395		mlog_errno(status);
2396		goto bail;
2397	}
2398
 
2399	if (undo_fn) {
2400		jbd_lock_bh_state(group_bh);
2401		undo_bg = (struct ocfs2_group_desc *)
2402					bh2jh(group_bh)->b_committed_data;
2403		BUG_ON(!undo_bg);
2404	}
2405
2406	tmp = num_bits;
2407	while(tmp--) {
2408		ocfs2_clear_bit((bit_off + tmp),
2409				(unsigned long *) bg->bg_bitmap);
2410		if (undo_fn)
2411			undo_fn(bit_off + tmp,
2412				(unsigned long *) undo_bg->bg_bitmap);
2413	}
2414	le16_add_cpu(&bg->bg_free_bits_count, num_bits);
2415	if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
 
 
2416		return ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit count %u but claims %u are freed. num_bits %d\n",
2417				   (unsigned long long)le64_to_cpu(bg->bg_blkno),
2418				   le16_to_cpu(bg->bg_bits),
2419				   le16_to_cpu(bg->bg_free_bits_count),
2420				   num_bits);
2421	}
2422
2423	if (undo_fn)
2424		jbd_unlock_bh_state(group_bh);
2425
2426	ocfs2_journal_dirty(handle, group_bh);
2427bail:
2428	return status;
2429}
2430
2431/*
2432 * expects the suballoc inode to already be locked.
2433 */
2434static int _ocfs2_free_suballoc_bits(handle_t *handle,
2435				     struct inode *alloc_inode,
2436				     struct buffer_head *alloc_bh,
2437				     unsigned int start_bit,
2438				     u64 bg_blkno,
2439				     unsigned int count,
2440				     void (*undo_fn)(unsigned int bit,
2441						     unsigned long *bitmap))
2442{
2443	int status = 0;
2444	u32 tmp_used;
2445	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
2446	struct ocfs2_chain_list *cl = &fe->id2.i_chain;
2447	struct buffer_head *group_bh = NULL;
2448	struct ocfs2_group_desc *group;
2449
2450	/* The alloc_bh comes from ocfs2_free_dinode() or
2451	 * ocfs2_free_clusters().  The callers have all locked the
2452	 * allocator and gotten alloc_bh from the lock call.  This
2453	 * validates the dinode buffer.  Any corruption that has happened
2454	 * is a code bug. */
2455	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
2456	BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
2457
2458	trace_ocfs2_free_suballoc_bits(
2459		(unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
2460		(unsigned long long)bg_blkno,
2461		start_bit, count);
2462
2463	status = ocfs2_read_group_descriptor(alloc_inode, fe, bg_blkno,
2464					     &group_bh);
2465	if (status < 0) {
2466		mlog_errno(status);
2467		goto bail;
2468	}
2469	group = (struct ocfs2_group_desc *) group_bh->b_data;
2470
2471	BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
2472
2473	status = ocfs2_block_group_clear_bits(handle, alloc_inode,
2474					      group, group_bh,
2475					      start_bit, count, undo_fn);
2476	if (status < 0) {
2477		mlog_errno(status);
2478		goto bail;
2479	}
2480
2481	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
2482					 alloc_bh, OCFS2_JOURNAL_ACCESS_WRITE);
2483	if (status < 0) {
2484		mlog_errno(status);
2485		ocfs2_block_group_set_bits(handle, alloc_inode, group, group_bh,
2486				start_bit, count);
2487		goto bail;
2488	}
2489
2490	le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
2491		     count);
2492	tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
2493	fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
2494	ocfs2_journal_dirty(handle, alloc_bh);
2495
2496bail:
2497	brelse(group_bh);
2498
2499	if (status)
2500		mlog_errno(status);
2501	return status;
2502}
2503
2504int ocfs2_free_suballoc_bits(handle_t *handle,
2505			     struct inode *alloc_inode,
2506			     struct buffer_head *alloc_bh,
2507			     unsigned int start_bit,
2508			     u64 bg_blkno,
2509			     unsigned int count)
2510{
2511	return _ocfs2_free_suballoc_bits(handle, alloc_inode, alloc_bh,
2512					 start_bit, bg_blkno, count, NULL);
2513}
2514
2515int ocfs2_free_dinode(handle_t *handle,
2516		      struct inode *inode_alloc_inode,
2517		      struct buffer_head *inode_alloc_bh,
2518		      struct ocfs2_dinode *di)
2519{
2520	u64 blk = le64_to_cpu(di->i_blkno);
2521	u16 bit = le16_to_cpu(di->i_suballoc_bit);
2522	u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
2523
2524	if (di->i_suballoc_loc)
2525		bg_blkno = le64_to_cpu(di->i_suballoc_loc);
2526	return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
2527					inode_alloc_bh, bit, bg_blkno, 1);
2528}
2529
2530static int _ocfs2_free_clusters(handle_t *handle,
2531				struct inode *bitmap_inode,
2532				struct buffer_head *bitmap_bh,
2533				u64 start_blk,
2534				unsigned int num_clusters,
2535				void (*undo_fn)(unsigned int bit,
2536						unsigned long *bitmap))
2537{
2538	int status;
2539	u16 bg_start_bit;
2540	u64 bg_blkno;
2541	struct ocfs2_dinode *fe;
2542
2543	/* You can't ever have a contiguous set of clusters
2544	 * bigger than a block group bitmap so we never have to worry
2545	 * about looping on them.
2546	 * This is expensive. We can safely remove once this stuff has
2547	 * gotten tested really well. */
2548	BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb, ocfs2_blocks_to_clusters(bitmap_inode->i_sb, start_blk)));
 
 
2549
2550	fe = (struct ocfs2_dinode *) bitmap_bh->b_data;
2551
2552	ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
2553				     &bg_start_bit);
2554
2555	trace_ocfs2_free_clusters((unsigned long long)bg_blkno,
2556			(unsigned long long)start_blk,
2557			bg_start_bit, num_clusters);
2558
2559	status = _ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
2560					   bg_start_bit, bg_blkno,
2561					   num_clusters, undo_fn);
2562	if (status < 0) {
2563		mlog_errno(status);
2564		goto out;
2565	}
2566
2567	ocfs2_local_alloc_seen_free_bits(OCFS2_SB(bitmap_inode->i_sb),
2568					 num_clusters);
2569
2570out:
2571	if (status)
2572		mlog_errno(status);
2573	return status;
2574}
2575
2576int ocfs2_free_clusters(handle_t *handle,
2577			struct inode *bitmap_inode,
2578			struct buffer_head *bitmap_bh,
2579			u64 start_blk,
2580			unsigned int num_clusters)
2581{
2582	return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2583				    start_blk, num_clusters,
2584				    _ocfs2_set_bit);
2585}
2586
2587/*
2588 * Give never-used clusters back to the global bitmap.  We don't need
2589 * to protect these bits in the undo buffer.
2590 */
2591int ocfs2_release_clusters(handle_t *handle,
2592			   struct inode *bitmap_inode,
2593			   struct buffer_head *bitmap_bh,
2594			   u64 start_blk,
2595			   unsigned int num_clusters)
2596{
2597	return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2598				    start_blk, num_clusters,
2599				    _ocfs2_clear_bit);
2600}
2601
2602static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg)
2603{
2604	printk("Block Group:\n");
2605	printk("bg_signature:       %s\n", bg->bg_signature);
2606	printk("bg_size:            %u\n", bg->bg_size);
2607	printk("bg_bits:            %u\n", bg->bg_bits);
2608	printk("bg_free_bits_count: %u\n", bg->bg_free_bits_count);
2609	printk("bg_chain:           %u\n", bg->bg_chain);
2610	printk("bg_generation:      %u\n", le32_to_cpu(bg->bg_generation));
2611	printk("bg_next_group:      %llu\n",
2612	       (unsigned long long)bg->bg_next_group);
2613	printk("bg_parent_dinode:   %llu\n",
2614	       (unsigned long long)bg->bg_parent_dinode);
2615	printk("bg_blkno:           %llu\n",
2616	       (unsigned long long)bg->bg_blkno);
2617}
2618
2619static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe)
2620{
2621	int i;
2622
2623	printk("Suballoc Inode %llu:\n", (unsigned long long)fe->i_blkno);
2624	printk("i_signature:                  %s\n", fe->i_signature);
2625	printk("i_size:                       %llu\n",
2626	       (unsigned long long)fe->i_size);
2627	printk("i_clusters:                   %u\n", fe->i_clusters);
2628	printk("i_generation:                 %u\n",
2629	       le32_to_cpu(fe->i_generation));
2630	printk("id1.bitmap1.i_used:           %u\n",
2631	       le32_to_cpu(fe->id1.bitmap1.i_used));
2632	printk("id1.bitmap1.i_total:          %u\n",
2633	       le32_to_cpu(fe->id1.bitmap1.i_total));
2634	printk("id2.i_chain.cl_cpg:           %u\n", fe->id2.i_chain.cl_cpg);
2635	printk("id2.i_chain.cl_bpc:           %u\n", fe->id2.i_chain.cl_bpc);
2636	printk("id2.i_chain.cl_count:         %u\n", fe->id2.i_chain.cl_count);
2637	printk("id2.i_chain.cl_next_free_rec: %u\n",
2638	       fe->id2.i_chain.cl_next_free_rec);
2639	for(i = 0; i < fe->id2.i_chain.cl_next_free_rec; i++) {
2640		printk("fe->id2.i_chain.cl_recs[%d].c_free:  %u\n", i,
2641		       fe->id2.i_chain.cl_recs[i].c_free);
2642		printk("fe->id2.i_chain.cl_recs[%d].c_total: %u\n", i,
2643		       fe->id2.i_chain.cl_recs[i].c_total);
2644		printk("fe->id2.i_chain.cl_recs[%d].c_blkno: %llu\n", i,
2645		       (unsigned long long)fe->id2.i_chain.cl_recs[i].c_blkno);
2646	}
2647}
2648
2649/*
2650 * For a given allocation, determine which allocators will need to be
2651 * accessed, and lock them, reserving the appropriate number of bits.
2652 *
2653 * Sparse file systems call this from ocfs2_write_begin_nolock()
2654 * and ocfs2_allocate_unwritten_extents().
2655 *
2656 * File systems which don't support holes call this from
2657 * ocfs2_extend_allocation().
2658 */
2659int ocfs2_lock_allocators(struct inode *inode,
2660			  struct ocfs2_extent_tree *et,
2661			  u32 clusters_to_add, u32 extents_to_split,
2662			  struct ocfs2_alloc_context **data_ac,
2663			  struct ocfs2_alloc_context **meta_ac)
2664{
2665	int ret = 0, num_free_extents;
2666	unsigned int max_recs_needed = clusters_to_add + 2 * extents_to_split;
2667	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2668
2669	*meta_ac = NULL;
2670	if (data_ac)
2671		*data_ac = NULL;
2672
2673	BUG_ON(clusters_to_add != 0 && data_ac == NULL);
2674
2675	num_free_extents = ocfs2_num_free_extents(osb, et);
2676	if (num_free_extents < 0) {
2677		ret = num_free_extents;
2678		mlog_errno(ret);
2679		goto out;
2680	}
2681
2682	/*
2683	 * Sparse allocation file systems need to be more conservative
2684	 * with reserving room for expansion - the actual allocation
2685	 * happens while we've got a journal handle open so re-taking
2686	 * a cluster lock (because we ran out of room for another
2687	 * extent) will violate ordering rules.
2688	 *
2689	 * Most of the time we'll only be seeing this 1 cluster at a time
2690	 * anyway.
2691	 *
2692	 * Always lock for any unwritten extents - we might want to
2693	 * add blocks during a split.
2694	 */
2695	if (!num_free_extents ||
2696	    (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed)) {
2697		ret = ocfs2_reserve_new_metadata(osb, et->et_root_el, meta_ac);
2698		if (ret < 0) {
2699			if (ret != -ENOSPC)
2700				mlog_errno(ret);
2701			goto out;
2702		}
2703	}
2704
2705	if (clusters_to_add == 0)
2706		goto out;
2707
2708	ret = ocfs2_reserve_clusters(osb, clusters_to_add, data_ac);
2709	if (ret < 0) {
2710		if (ret != -ENOSPC)
2711			mlog_errno(ret);
2712		goto out;
2713	}
2714
2715out:
2716	if (ret) {
2717		if (*meta_ac) {
2718			ocfs2_free_alloc_context(*meta_ac);
2719			*meta_ac = NULL;
2720		}
2721
2722		/*
2723		 * We cannot have an error and a non null *data_ac.
2724		 */
2725	}
2726
2727	return ret;
2728}
2729
2730/*
2731 * Read the inode specified by blkno to get suballoc_slot and
2732 * suballoc_bit.
2733 */
2734static int ocfs2_get_suballoc_slot_bit(struct ocfs2_super *osb, u64 blkno,
2735				       u16 *suballoc_slot, u64 *group_blkno,
2736				       u16 *suballoc_bit)
2737{
2738	int status;
2739	struct buffer_head *inode_bh = NULL;
2740	struct ocfs2_dinode *inode_fe;
2741
2742	trace_ocfs2_get_suballoc_slot_bit((unsigned long long)blkno);
2743
2744	/* dirty read disk */
2745	status = ocfs2_read_blocks_sync(osb, blkno, 1, &inode_bh);
2746	if (status < 0) {
2747		mlog(ML_ERROR, "read block %llu failed %d\n",
2748		     (unsigned long long)blkno, status);
2749		goto bail;
2750	}
2751
2752	inode_fe = (struct ocfs2_dinode *) inode_bh->b_data;
2753	if (!OCFS2_IS_VALID_DINODE(inode_fe)) {
2754		mlog(ML_ERROR, "invalid inode %llu requested\n",
2755		     (unsigned long long)blkno);
2756		status = -EINVAL;
2757		goto bail;
2758	}
2759
2760	if (le16_to_cpu(inode_fe->i_suballoc_slot) != (u16)OCFS2_INVALID_SLOT &&
2761	    (u32)le16_to_cpu(inode_fe->i_suballoc_slot) > osb->max_slots - 1) {
2762		mlog(ML_ERROR, "inode %llu has invalid suballoc slot %u\n",
2763		     (unsigned long long)blkno,
2764		     (u32)le16_to_cpu(inode_fe->i_suballoc_slot));
2765		status = -EINVAL;
2766		goto bail;
2767	}
2768
2769	if (suballoc_slot)
2770		*suballoc_slot = le16_to_cpu(inode_fe->i_suballoc_slot);
2771	if (suballoc_bit)
2772		*suballoc_bit = le16_to_cpu(inode_fe->i_suballoc_bit);
2773	if (group_blkno)
2774		*group_blkno = le64_to_cpu(inode_fe->i_suballoc_loc);
2775
2776bail:
2777	brelse(inode_bh);
2778
2779	if (status)
2780		mlog_errno(status);
2781	return status;
2782}
2783
2784/*
2785 * test whether bit is SET in allocator bitmap or not.  on success, 0
2786 * is returned and *res is 1 for SET; 0 otherwise.  when fails, errno
2787 * is returned and *res is meaningless.  Call this after you have
2788 * cluster locked against suballoc, or you may get a result based on
2789 * non-up2date contents
2790 */
2791static int ocfs2_test_suballoc_bit(struct ocfs2_super *osb,
2792				   struct inode *suballoc,
2793				   struct buffer_head *alloc_bh,
2794				   u64 group_blkno, u64 blkno,
2795				   u16 bit, int *res)
2796{
2797	struct ocfs2_dinode *alloc_di;
2798	struct ocfs2_group_desc *group;
2799	struct buffer_head *group_bh = NULL;
2800	u64 bg_blkno;
2801	int status;
2802
2803	trace_ocfs2_test_suballoc_bit((unsigned long long)blkno,
2804				      (unsigned int)bit);
2805
2806	alloc_di = (struct ocfs2_dinode *)alloc_bh->b_data;
2807	if ((bit + 1) > ocfs2_bits_per_group(&alloc_di->id2.i_chain)) {
2808		mlog(ML_ERROR, "suballoc bit %u out of range of %u\n",
2809		     (unsigned int)bit,
2810		     ocfs2_bits_per_group(&alloc_di->id2.i_chain));
2811		status = -EINVAL;
2812		goto bail;
2813	}
2814
2815	bg_blkno = group_blkno ? group_blkno :
2816		   ocfs2_which_suballoc_group(blkno, bit);
2817	status = ocfs2_read_group_descriptor(suballoc, alloc_di, bg_blkno,
2818					     &group_bh);
2819	if (status < 0) {
2820		mlog(ML_ERROR, "read group %llu failed %d\n",
2821		     (unsigned long long)bg_blkno, status);
2822		goto bail;
2823	}
2824
2825	group = (struct ocfs2_group_desc *) group_bh->b_data;
2826	*res = ocfs2_test_bit(bit, (unsigned long *)group->bg_bitmap);
2827
2828bail:
2829	brelse(group_bh);
2830
2831	if (status)
2832		mlog_errno(status);
2833	return status;
2834}
2835
2836/*
2837 * Test if the bit representing this inode (blkno) is set in the
2838 * suballocator.
2839 *
2840 * On success, 0 is returned and *res is 1 for SET; 0 otherwise.
2841 *
2842 * In the event of failure, a negative value is returned and *res is
2843 * meaningless.
2844 *
2845 * Callers must make sure to hold nfs_sync_lock to prevent
2846 * ocfs2_delete_inode() on another node from accessing the same
2847 * suballocator concurrently.
2848 */
2849int ocfs2_test_inode_bit(struct ocfs2_super *osb, u64 blkno, int *res)
2850{
2851	int status;
2852	u64 group_blkno = 0;
2853	u16 suballoc_bit = 0, suballoc_slot = 0;
2854	struct inode *inode_alloc_inode;
2855	struct buffer_head *alloc_bh = NULL;
2856
2857	trace_ocfs2_test_inode_bit((unsigned long long)blkno);
2858
2859	status = ocfs2_get_suballoc_slot_bit(osb, blkno, &suballoc_slot,
2860					     &group_blkno, &suballoc_bit);
2861	if (status < 0) {
2862		mlog(ML_ERROR, "get alloc slot and bit failed %d\n", status);
2863		goto bail;
2864	}
2865
2866	inode_alloc_inode =
2867		ocfs2_get_system_file_inode(osb, INODE_ALLOC_SYSTEM_INODE,
2868					    suballoc_slot);
 
 
 
2869	if (!inode_alloc_inode) {
2870		/* the error code could be inaccurate, but we are not able to
2871		 * get the correct one. */
2872		status = -EINVAL;
2873		mlog(ML_ERROR, "unable to get alloc inode in slot %u\n",
2874		     (u32)suballoc_slot);
2875		goto bail;
2876	}
2877
2878	inode_lock(inode_alloc_inode);
2879	status = ocfs2_inode_lock(inode_alloc_inode, &alloc_bh, 0);
2880	if (status < 0) {
2881		inode_unlock(inode_alloc_inode);
2882		iput(inode_alloc_inode);
2883		mlog(ML_ERROR, "lock on alloc inode on slot %u failed %d\n",
2884		     (u32)suballoc_slot, status);
2885		goto bail;
2886	}
2887
2888	status = ocfs2_test_suballoc_bit(osb, inode_alloc_inode, alloc_bh,
2889					 group_blkno, blkno, suballoc_bit, res);
2890	if (status < 0)
2891		mlog(ML_ERROR, "test suballoc bit failed %d\n", status);
2892
2893	ocfs2_inode_unlock(inode_alloc_inode, 0);
2894	inode_unlock(inode_alloc_inode);
2895
2896	iput(inode_alloc_inode);
2897	brelse(alloc_bh);
2898bail:
2899	if (status)
2900		mlog_errno(status);
2901	return status;
2902}