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v6.2
   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
 
   3 * suballoc.c
   4 *
   5 * metadata alloc and free
   6 * Inspired by ext3 block groups.
   7 *
   8 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
   9 */
  10
  11#include <linux/fs.h>
  12#include <linux/types.h>
  13#include <linux/slab.h>
  14#include <linux/highmem.h>
  15
  16#include <cluster/masklog.h>
  17
  18#include "ocfs2.h"
  19
  20#include "alloc.h"
  21#include "blockcheck.h"
  22#include "dlmglue.h"
  23#include "inode.h"
  24#include "journal.h"
  25#include "localalloc.h"
  26#include "suballoc.h"
  27#include "super.h"
  28#include "sysfile.h"
  29#include "uptodate.h"
  30#include "ocfs2_trace.h"
  31
  32#include "buffer_head_io.h"
  33
  34#define NOT_ALLOC_NEW_GROUP		0
  35#define ALLOC_NEW_GROUP			0x1
  36#define ALLOC_GROUPS_FROM_GLOBAL	0x2
  37
  38#define OCFS2_MAX_TO_STEAL		1024
  39
  40struct ocfs2_suballoc_result {
  41	u64		sr_bg_blkno;	/* The bg we allocated from.  Set
  42					   to 0 when a block group is
  43					   contiguous. */
  44	u64		sr_bg_stable_blkno; /*
  45					     * Doesn't change, always
  46					     * set to target block
  47					     * group descriptor
  48					     * block.
  49					     */
  50	u64		sr_blkno;	/* The first allocated block */
  51	unsigned int	sr_bit_offset;	/* The bit in the bg */
  52	unsigned int	sr_bits;	/* How many bits we claimed */
  53};
  54
  55static u64 ocfs2_group_from_res(struct ocfs2_suballoc_result *res)
  56{
  57	if (res->sr_blkno == 0)
  58		return 0;
  59
  60	if (res->sr_bg_blkno)
  61		return res->sr_bg_blkno;
  62
  63	return ocfs2_which_suballoc_group(res->sr_blkno, res->sr_bit_offset);
  64}
  65
 
 
  66static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl);
  67static int ocfs2_block_group_fill(handle_t *handle,
  68				  struct inode *alloc_inode,
  69				  struct buffer_head *bg_bh,
  70				  u64 group_blkno,
  71				  unsigned int group_clusters,
  72				  u16 my_chain,
  73				  struct ocfs2_chain_list *cl);
  74static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
  75				   struct inode *alloc_inode,
  76				   struct buffer_head *bh,
  77				   u64 max_block,
  78				   u64 *last_alloc_group,
  79				   int flags);
  80
  81static int ocfs2_cluster_group_search(struct inode *inode,
  82				      struct buffer_head *group_bh,
  83				      u32 bits_wanted, u32 min_bits,
  84				      u64 max_block,
  85				      struct ocfs2_suballoc_result *res);
  86static int ocfs2_block_group_search(struct inode *inode,
  87				    struct buffer_head *group_bh,
  88				    u32 bits_wanted, u32 min_bits,
  89				    u64 max_block,
  90				    struct ocfs2_suballoc_result *res);
  91static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
  92				     handle_t *handle,
  93				     u32 bits_wanted,
  94				     u32 min_bits,
  95				     struct ocfs2_suballoc_result *res);
  96static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
  97					 int nr);
  98static int ocfs2_relink_block_group(handle_t *handle,
  99				    struct inode *alloc_inode,
 100				    struct buffer_head *fe_bh,
 101				    struct buffer_head *bg_bh,
 102				    struct buffer_head *prev_bg_bh,
 103				    u16 chain);
 104static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
 105						     u32 wanted);
 106static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
 107						   u64 bg_blkno,
 108						   u16 bg_bit_off);
 109static inline void ocfs2_block_to_cluster_group(struct inode *inode,
 110						u64 data_blkno,
 111						u64 *bg_blkno,
 112						u16 *bg_bit_off);
 113static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
 114					     u32 bits_wanted, u64 max_block,
 115					     int flags,
 116					     struct ocfs2_alloc_context **ac);
 117
 118void ocfs2_free_ac_resource(struct ocfs2_alloc_context *ac)
 119{
 120	struct inode *inode = ac->ac_inode;
 121
 122	if (inode) {
 123		if (ac->ac_which != OCFS2_AC_USE_LOCAL)
 124			ocfs2_inode_unlock(inode, 1);
 125
 126		inode_unlock(inode);
 127
 128		iput(inode);
 129		ac->ac_inode = NULL;
 130	}
 131	brelse(ac->ac_bh);
 132	ac->ac_bh = NULL;
 133	ac->ac_resv = NULL;
 134	kfree(ac->ac_find_loc_priv);
 135	ac->ac_find_loc_priv = NULL;
 136}
 137
 138void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
 139{
 140	ocfs2_free_ac_resource(ac);
 141	kfree(ac);
 142}
 143
 144static u32 ocfs2_bits_per_group(struct ocfs2_chain_list *cl)
 145{
 146	return (u32)le16_to_cpu(cl->cl_cpg) * (u32)le16_to_cpu(cl->cl_bpc);
 147}
 148
 149#define do_error(fmt, ...)						\
 150do {									\
 151	if (resize)							\
 152		mlog(ML_ERROR, fmt, ##__VA_ARGS__);			\
 153	else								\
 154		return ocfs2_error(sb, fmt, ##__VA_ARGS__);		\
 155} while (0)
 156
 157static int ocfs2_validate_gd_self(struct super_block *sb,
 158				  struct buffer_head *bh,
 159				  int resize)
 160{
 161	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 162
 163	if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
 164		do_error("Group descriptor #%llu has bad signature %.*s\n",
 165			 (unsigned long long)bh->b_blocknr, 7,
 166			 gd->bg_signature);
 167	}
 168
 169	if (le64_to_cpu(gd->bg_blkno) != bh->b_blocknr) {
 170		do_error("Group descriptor #%llu has an invalid bg_blkno of %llu\n",
 171			 (unsigned long long)bh->b_blocknr,
 172			 (unsigned long long)le64_to_cpu(gd->bg_blkno));
 173	}
 174
 175	if (le32_to_cpu(gd->bg_generation) != OCFS2_SB(sb)->fs_generation) {
 176		do_error("Group descriptor #%llu has an invalid fs_generation of #%u\n",
 177			 (unsigned long long)bh->b_blocknr,
 178			 le32_to_cpu(gd->bg_generation));
 179	}
 180
 181	if (le16_to_cpu(gd->bg_free_bits_count) > le16_to_cpu(gd->bg_bits)) {
 182		do_error("Group descriptor #%llu has bit count %u but claims that %u are free\n",
 183			 (unsigned long long)bh->b_blocknr,
 184			 le16_to_cpu(gd->bg_bits),
 185			 le16_to_cpu(gd->bg_free_bits_count));
 186	}
 187
 188	if (le16_to_cpu(gd->bg_bits) > (8 * le16_to_cpu(gd->bg_size))) {
 189		do_error("Group descriptor #%llu has bit count %u but max bitmap bits of %u\n",
 190			 (unsigned long long)bh->b_blocknr,
 191			 le16_to_cpu(gd->bg_bits),
 192			 8 * le16_to_cpu(gd->bg_size));
 193	}
 194
 195	return 0;
 196}
 197
 198static int ocfs2_validate_gd_parent(struct super_block *sb,
 199				    struct ocfs2_dinode *di,
 200				    struct buffer_head *bh,
 201				    int resize)
 202{
 203	unsigned int max_bits;
 204	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 205
 206	if (di->i_blkno != gd->bg_parent_dinode) {
 207		do_error("Group descriptor #%llu has bad parent pointer (%llu, expected %llu)\n",
 208			 (unsigned long long)bh->b_blocknr,
 209			 (unsigned long long)le64_to_cpu(gd->bg_parent_dinode),
 210			 (unsigned long long)le64_to_cpu(di->i_blkno));
 211	}
 212
 213	max_bits = le16_to_cpu(di->id2.i_chain.cl_cpg) * le16_to_cpu(di->id2.i_chain.cl_bpc);
 214	if (le16_to_cpu(gd->bg_bits) > max_bits) {
 215		do_error("Group descriptor #%llu has bit count of %u\n",
 216			 (unsigned long long)bh->b_blocknr,
 217			 le16_to_cpu(gd->bg_bits));
 218	}
 219
 220	/* In resize, we may meet the case bg_chain == cl_next_free_rec. */
 221	if ((le16_to_cpu(gd->bg_chain) >
 222	     le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) ||
 223	    ((le16_to_cpu(gd->bg_chain) ==
 224	     le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) && !resize)) {
 225		do_error("Group descriptor #%llu has bad chain %u\n",
 226			 (unsigned long long)bh->b_blocknr,
 227			 le16_to_cpu(gd->bg_chain));
 228	}
 229
 230	return 0;
 231}
 232
 233#undef do_error
 234
 235/*
 236 * This version only prints errors.  It does not fail the filesystem, and
 237 * exists only for resize.
 238 */
 239int ocfs2_check_group_descriptor(struct super_block *sb,
 240				 struct ocfs2_dinode *di,
 241				 struct buffer_head *bh)
 242{
 243	int rc;
 244	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 245
 246	BUG_ON(!buffer_uptodate(bh));
 247
 248	/*
 249	 * If the ecc fails, we return the error but otherwise
 250	 * leave the filesystem running.  We know any error is
 251	 * local to this block.
 252	 */
 253	rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
 254	if (rc) {
 255		mlog(ML_ERROR,
 256		     "Checksum failed for group descriptor %llu\n",
 257		     (unsigned long long)bh->b_blocknr);
 258	} else
 259		rc = ocfs2_validate_gd_self(sb, bh, 1);
 260	if (!rc)
 261		rc = ocfs2_validate_gd_parent(sb, di, bh, 1);
 262
 263	return rc;
 264}
 265
 266static int ocfs2_validate_group_descriptor(struct super_block *sb,
 267					   struct buffer_head *bh)
 268{
 269	int rc;
 270	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 271
 272	trace_ocfs2_validate_group_descriptor(
 273					(unsigned long long)bh->b_blocknr);
 274
 275	BUG_ON(!buffer_uptodate(bh));
 276
 277	/*
 278	 * If the ecc fails, we return the error but otherwise
 279	 * leave the filesystem running.  We know any error is
 280	 * local to this block.
 281	 */
 282	rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
 283	if (rc)
 284		return rc;
 285
 286	/*
 287	 * Errors after here are fatal.
 288	 */
 289
 290	return ocfs2_validate_gd_self(sb, bh, 0);
 291}
 292
 293int ocfs2_read_group_descriptor(struct inode *inode, struct ocfs2_dinode *di,
 294				u64 gd_blkno, struct buffer_head **bh)
 295{
 296	int rc;
 297	struct buffer_head *tmp = *bh;
 298
 299	rc = ocfs2_read_block(INODE_CACHE(inode), gd_blkno, &tmp,
 300			      ocfs2_validate_group_descriptor);
 301	if (rc)
 302		goto out;
 303
 304	rc = ocfs2_validate_gd_parent(inode->i_sb, di, tmp, 0);
 305	if (rc) {
 306		brelse(tmp);
 307		goto out;
 308	}
 309
 310	/* If ocfs2_read_block() got us a new bh, pass it up. */
 311	if (!*bh)
 312		*bh = tmp;
 313
 314out:
 315	return rc;
 316}
 317
 318static void ocfs2_bg_discontig_add_extent(struct ocfs2_super *osb,
 319					  struct ocfs2_group_desc *bg,
 320					  struct ocfs2_chain_list *cl,
 321					  u64 p_blkno, unsigned int clusters)
 322{
 323	struct ocfs2_extent_list *el = &bg->bg_list;
 324	struct ocfs2_extent_rec *rec;
 325
 326	BUG_ON(!ocfs2_supports_discontig_bg(osb));
 327	if (!el->l_next_free_rec)
 328		el->l_count = cpu_to_le16(ocfs2_extent_recs_per_gd(osb->sb));
 329	rec = &el->l_recs[le16_to_cpu(el->l_next_free_rec)];
 330	rec->e_blkno = cpu_to_le64(p_blkno);
 331	rec->e_cpos = cpu_to_le32(le16_to_cpu(bg->bg_bits) /
 332				  le16_to_cpu(cl->cl_bpc));
 333	rec->e_leaf_clusters = cpu_to_le16(clusters);
 334	le16_add_cpu(&bg->bg_bits, clusters * le16_to_cpu(cl->cl_bpc));
 335	le16_add_cpu(&bg->bg_free_bits_count,
 336		     clusters * le16_to_cpu(cl->cl_bpc));
 337	le16_add_cpu(&el->l_next_free_rec, 1);
 338}
 339
 340static int ocfs2_block_group_fill(handle_t *handle,
 341				  struct inode *alloc_inode,
 342				  struct buffer_head *bg_bh,
 343				  u64 group_blkno,
 344				  unsigned int group_clusters,
 345				  u16 my_chain,
 346				  struct ocfs2_chain_list *cl)
 347{
 348	int status = 0;
 349	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 350	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 351	struct super_block * sb = alloc_inode->i_sb;
 352
 353	if (((unsigned long long) bg_bh->b_blocknr) != group_blkno) {
 354		status = ocfs2_error(alloc_inode->i_sb,
 355				     "group block (%llu) != b_blocknr (%llu)\n",
 356				     (unsigned long long)group_blkno,
 357				     (unsigned long long) bg_bh->b_blocknr);
 358		goto bail;
 359	}
 360
 361	status = ocfs2_journal_access_gd(handle,
 362					 INODE_CACHE(alloc_inode),
 363					 bg_bh,
 364					 OCFS2_JOURNAL_ACCESS_CREATE);
 365	if (status < 0) {
 366		mlog_errno(status);
 367		goto bail;
 368	}
 369
 370	memset(bg, 0, sb->s_blocksize);
 371	strcpy(bg->bg_signature, OCFS2_GROUP_DESC_SIGNATURE);
 372	bg->bg_generation = cpu_to_le32(osb->fs_generation);
 373	bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb, 1,
 374						osb->s_feature_incompat));
 375	bg->bg_chain = cpu_to_le16(my_chain);
 376	bg->bg_next_group = cl->cl_recs[my_chain].c_blkno;
 377	bg->bg_parent_dinode = cpu_to_le64(OCFS2_I(alloc_inode)->ip_blkno);
 378	bg->bg_blkno = cpu_to_le64(group_blkno);
 379	if (group_clusters == le16_to_cpu(cl->cl_cpg))
 380		bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
 381	else
 382		ocfs2_bg_discontig_add_extent(osb, bg, cl, group_blkno,
 383					      group_clusters);
 384
 385	/* set the 1st bit in the bitmap to account for the descriptor block */
 386	ocfs2_set_bit(0, (unsigned long *)bg->bg_bitmap);
 387	bg->bg_free_bits_count = cpu_to_le16(le16_to_cpu(bg->bg_bits) - 1);
 388
 389	ocfs2_journal_dirty(handle, bg_bh);
 390
 391	/* There is no need to zero out or otherwise initialize the
 392	 * other blocks in a group - All valid FS metadata in a block
 393	 * group stores the superblock fs_generation value at
 394	 * allocation time. */
 395
 396bail:
 397	if (status)
 398		mlog_errno(status);
 399	return status;
 400}
 401
 402static inline u16 ocfs2_find_smallest_chain(struct ocfs2_chain_list *cl)
 403{
 404	u16 curr, best;
 405
 406	best = curr = 0;
 407	while (curr < le16_to_cpu(cl->cl_count)) {
 408		if (le32_to_cpu(cl->cl_recs[best].c_total) >
 409		    le32_to_cpu(cl->cl_recs[curr].c_total))
 410			best = curr;
 411		curr++;
 412	}
 413	return best;
 414}
 415
 416static struct buffer_head *
 417ocfs2_block_group_alloc_contig(struct ocfs2_super *osb, handle_t *handle,
 418			       struct inode *alloc_inode,
 419			       struct ocfs2_alloc_context *ac,
 420			       struct ocfs2_chain_list *cl)
 421{
 422	int status;
 423	u32 bit_off, num_bits;
 424	u64 bg_blkno;
 425	struct buffer_head *bg_bh;
 426	unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
 427
 428	status = ocfs2_claim_clusters(handle, ac,
 429				      le16_to_cpu(cl->cl_cpg), &bit_off,
 430				      &num_bits);
 431	if (status < 0) {
 432		if (status != -ENOSPC)
 433			mlog_errno(status);
 434		goto bail;
 435	}
 436
 437	/* setup the group */
 438	bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 439	trace_ocfs2_block_group_alloc_contig(
 440	     (unsigned long long)bg_blkno, alloc_rec);
 441
 442	bg_bh = sb_getblk(osb->sb, bg_blkno);
 443	if (!bg_bh) {
 444		status = -ENOMEM;
 445		mlog_errno(status);
 446		goto bail;
 447	}
 448	ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
 449
 450	status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
 451					bg_blkno, num_bits, alloc_rec, cl);
 452	if (status < 0) {
 453		brelse(bg_bh);
 454		mlog_errno(status);
 455	}
 456
 457bail:
 458	return status ? ERR_PTR(status) : bg_bh;
 459}
 460
 461static int ocfs2_block_group_claim_bits(struct ocfs2_super *osb,
 462					handle_t *handle,
 463					struct ocfs2_alloc_context *ac,
 464					unsigned int min_bits,
 465					u32 *bit_off, u32 *num_bits)
 466{
 467	int status = 0;
 468
 469	while (min_bits) {
 470		status = ocfs2_claim_clusters(handle, ac, min_bits,
 471					      bit_off, num_bits);
 472		if (status != -ENOSPC)
 473			break;
 474
 475		min_bits >>= 1;
 476	}
 477
 478	return status;
 479}
 480
 481static int ocfs2_block_group_grow_discontig(handle_t *handle,
 482					    struct inode *alloc_inode,
 483					    struct buffer_head *bg_bh,
 484					    struct ocfs2_alloc_context *ac,
 485					    struct ocfs2_chain_list *cl,
 486					    unsigned int min_bits)
 487{
 488	int status;
 489	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 490	struct ocfs2_group_desc *bg =
 491		(struct ocfs2_group_desc *)bg_bh->b_data;
 492	unsigned int needed = le16_to_cpu(cl->cl_cpg) -
 493			 le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
 494	u32 p_cpos, clusters;
 495	u64 p_blkno;
 496	struct ocfs2_extent_list *el = &bg->bg_list;
 497
 498	status = ocfs2_journal_access_gd(handle,
 499					 INODE_CACHE(alloc_inode),
 500					 bg_bh,
 501					 OCFS2_JOURNAL_ACCESS_CREATE);
 502	if (status < 0) {
 503		mlog_errno(status);
 504		goto bail;
 505	}
 506
 507	while ((needed > 0) && (le16_to_cpu(el->l_next_free_rec) <
 508				le16_to_cpu(el->l_count))) {
 509		if (min_bits > needed)
 510			min_bits = needed;
 511		status = ocfs2_block_group_claim_bits(osb, handle, ac,
 512						      min_bits, &p_cpos,
 513						      &clusters);
 514		if (status < 0) {
 515			if (status != -ENOSPC)
 516				mlog_errno(status);
 517			goto bail;
 518		}
 519		p_blkno = ocfs2_clusters_to_blocks(osb->sb, p_cpos);
 520		ocfs2_bg_discontig_add_extent(osb, bg, cl, p_blkno,
 521					      clusters);
 522
 523		min_bits = clusters;
 524		needed = le16_to_cpu(cl->cl_cpg) -
 525			 le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
 526	}
 527
 528	if (needed > 0) {
 529		/*
 530		 * We have used up all the extent rec but can't fill up
 531		 * the cpg. So bail out.
 532		 */
 533		status = -ENOSPC;
 534		goto bail;
 535	}
 536
 537	ocfs2_journal_dirty(handle, bg_bh);
 538
 539bail:
 540	return status;
 541}
 542
 543static void ocfs2_bg_alloc_cleanup(handle_t *handle,
 544				   struct ocfs2_alloc_context *cluster_ac,
 545				   struct inode *alloc_inode,
 546				   struct buffer_head *bg_bh)
 547{
 548	int i, ret;
 549	struct ocfs2_group_desc *bg;
 550	struct ocfs2_extent_list *el;
 551	struct ocfs2_extent_rec *rec;
 552
 553	if (!bg_bh)
 554		return;
 555
 556	bg = (struct ocfs2_group_desc *)bg_bh->b_data;
 557	el = &bg->bg_list;
 558	for (i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
 559		rec = &el->l_recs[i];
 560		ret = ocfs2_free_clusters(handle, cluster_ac->ac_inode,
 561					  cluster_ac->ac_bh,
 562					  le64_to_cpu(rec->e_blkno),
 563					  le16_to_cpu(rec->e_leaf_clusters));
 564		if (ret)
 565			mlog_errno(ret);
 566		/* Try all the clusters to free */
 567	}
 568
 569	ocfs2_remove_from_cache(INODE_CACHE(alloc_inode), bg_bh);
 570	brelse(bg_bh);
 571}
 572
 573static struct buffer_head *
 574ocfs2_block_group_alloc_discontig(handle_t *handle,
 575				  struct inode *alloc_inode,
 576				  struct ocfs2_alloc_context *ac,
 577				  struct ocfs2_chain_list *cl)
 578{
 579	int status;
 580	u32 bit_off, num_bits;
 581	u64 bg_blkno;
 582	unsigned int min_bits = le16_to_cpu(cl->cl_cpg) >> 1;
 583	struct buffer_head *bg_bh = NULL;
 584	unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
 585	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 586
 587	if (!ocfs2_supports_discontig_bg(osb)) {
 588		status = -ENOSPC;
 589		goto bail;
 590	}
 591
 592	status = ocfs2_extend_trans(handle,
 593				    ocfs2_calc_bg_discontig_credits(osb->sb));
 594	if (status) {
 595		mlog_errno(status);
 596		goto bail;
 597	}
 598
 599	/*
 600	 * We're going to be grabbing from multiple cluster groups.
 601	 * We don't have enough credits to relink them all, and the
 602	 * cluster groups will be staying in cache for the duration of
 603	 * this operation.
 604	 */
 605	ac->ac_disable_chain_relink = 1;
 606
 607	/* Claim the first region */
 608	status = ocfs2_block_group_claim_bits(osb, handle, ac, min_bits,
 609					      &bit_off, &num_bits);
 610	if (status < 0) {
 611		if (status != -ENOSPC)
 612			mlog_errno(status);
 613		goto bail;
 614	}
 615	min_bits = num_bits;
 616
 617	/* setup the group */
 618	bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 619	trace_ocfs2_block_group_alloc_discontig(
 620				(unsigned long long)bg_blkno, alloc_rec);
 621
 622	bg_bh = sb_getblk(osb->sb, bg_blkno);
 623	if (!bg_bh) {
 624		status = -ENOMEM;
 625		mlog_errno(status);
 626		goto bail;
 627	}
 628	ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
 629
 630	status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
 631					bg_blkno, num_bits, alloc_rec, cl);
 632	if (status < 0) {
 633		mlog_errno(status);
 634		goto bail;
 635	}
 636
 637	status = ocfs2_block_group_grow_discontig(handle, alloc_inode,
 638						  bg_bh, ac, cl, min_bits);
 639	if (status)
 640		mlog_errno(status);
 641
 642bail:
 643	if (status)
 644		ocfs2_bg_alloc_cleanup(handle, ac, alloc_inode, bg_bh);
 645	return status ? ERR_PTR(status) : bg_bh;
 646}
 647
 648/*
 649 * We expect the block group allocator to already be locked.
 650 */
 651static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
 652				   struct inode *alloc_inode,
 653				   struct buffer_head *bh,
 654				   u64 max_block,
 655				   u64 *last_alloc_group,
 656				   int flags)
 657{
 658	int status, credits;
 659	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) bh->b_data;
 660	struct ocfs2_chain_list *cl;
 661	struct ocfs2_alloc_context *ac = NULL;
 662	handle_t *handle = NULL;
 663	u16 alloc_rec;
 664	struct buffer_head *bg_bh = NULL;
 665	struct ocfs2_group_desc *bg;
 666
 667	BUG_ON(ocfs2_is_cluster_bitmap(alloc_inode));
 668
 669	cl = &fe->id2.i_chain;
 670	status = ocfs2_reserve_clusters_with_limit(osb,
 671						   le16_to_cpu(cl->cl_cpg),
 672						   max_block, flags, &ac);
 673	if (status < 0) {
 674		if (status != -ENOSPC)
 675			mlog_errno(status);
 676		goto bail;
 677	}
 678
 679	credits = ocfs2_calc_group_alloc_credits(osb->sb,
 680						 le16_to_cpu(cl->cl_cpg));
 681	handle = ocfs2_start_trans(osb, credits);
 682	if (IS_ERR(handle)) {
 683		status = PTR_ERR(handle);
 684		handle = NULL;
 685		mlog_errno(status);
 686		goto bail;
 687	}
 688
 689	if (last_alloc_group && *last_alloc_group != 0) {
 690		trace_ocfs2_block_group_alloc(
 691				(unsigned long long)*last_alloc_group);
 692		ac->ac_last_group = *last_alloc_group;
 693	}
 694
 695	bg_bh = ocfs2_block_group_alloc_contig(osb, handle, alloc_inode,
 696					       ac, cl);
 697	if (PTR_ERR(bg_bh) == -ENOSPC)
 698		bg_bh = ocfs2_block_group_alloc_discontig(handle,
 699							  alloc_inode,
 700							  ac, cl);
 701	if (IS_ERR(bg_bh)) {
 702		status = PTR_ERR(bg_bh);
 703		bg_bh = NULL;
 704		if (status != -ENOSPC)
 705			mlog_errno(status);
 706		goto bail;
 707	}
 708	bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 709
 710	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
 711					 bh, OCFS2_JOURNAL_ACCESS_WRITE);
 712	if (status < 0) {
 713		mlog_errno(status);
 714		goto bail;
 715	}
 716
 717	alloc_rec = le16_to_cpu(bg->bg_chain);
 718	le32_add_cpu(&cl->cl_recs[alloc_rec].c_free,
 719		     le16_to_cpu(bg->bg_free_bits_count));
 720	le32_add_cpu(&cl->cl_recs[alloc_rec].c_total,
 721		     le16_to_cpu(bg->bg_bits));
 722	cl->cl_recs[alloc_rec].c_blkno = bg->bg_blkno;
 723	if (le16_to_cpu(cl->cl_next_free_rec) < le16_to_cpu(cl->cl_count))
 724		le16_add_cpu(&cl->cl_next_free_rec, 1);
 725
 726	le32_add_cpu(&fe->id1.bitmap1.i_used, le16_to_cpu(bg->bg_bits) -
 727					le16_to_cpu(bg->bg_free_bits_count));
 728	le32_add_cpu(&fe->id1.bitmap1.i_total, le16_to_cpu(bg->bg_bits));
 729	le32_add_cpu(&fe->i_clusters, le16_to_cpu(cl->cl_cpg));
 730
 731	ocfs2_journal_dirty(handle, bh);
 732
 733	spin_lock(&OCFS2_I(alloc_inode)->ip_lock);
 734	OCFS2_I(alloc_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
 735	fe->i_size = cpu_to_le64(ocfs2_clusters_to_bytes(alloc_inode->i_sb,
 736					     le32_to_cpu(fe->i_clusters)));
 737	spin_unlock(&OCFS2_I(alloc_inode)->ip_lock);
 738	i_size_write(alloc_inode, le64_to_cpu(fe->i_size));
 739	alloc_inode->i_blocks = ocfs2_inode_sector_count(alloc_inode);
 740	ocfs2_update_inode_fsync_trans(handle, alloc_inode, 0);
 741
 742	status = 0;
 743
 744	/* save the new last alloc group so that the caller can cache it. */
 745	if (last_alloc_group)
 746		*last_alloc_group = ac->ac_last_group;
 747
 748bail:
 749	if (handle)
 750		ocfs2_commit_trans(osb, handle);
 751
 752	if (ac)
 753		ocfs2_free_alloc_context(ac);
 754
 755	brelse(bg_bh);
 756
 757	if (status)
 758		mlog_errno(status);
 759	return status;
 760}
 761
 762static int ocfs2_reserve_suballoc_bits(struct ocfs2_super *osb,
 763				       struct ocfs2_alloc_context *ac,
 764				       int type,
 765				       u32 slot,
 766				       u64 *last_alloc_group,
 767				       int flags)
 768{
 769	int status;
 770	u32 bits_wanted = ac->ac_bits_wanted;
 771	struct inode *alloc_inode;
 772	struct buffer_head *bh = NULL;
 773	struct ocfs2_dinode *fe;
 774	u32 free_bits;
 775
 776	alloc_inode = ocfs2_get_system_file_inode(osb, type, slot);
 777	if (!alloc_inode) {
 778		mlog_errno(-EINVAL);
 779		return -EINVAL;
 780	}
 781
 782	inode_lock(alloc_inode);
 783
 784	status = ocfs2_inode_lock(alloc_inode, &bh, 1);
 785	if (status < 0) {
 786		inode_unlock(alloc_inode);
 787		iput(alloc_inode);
 788
 789		mlog_errno(status);
 790		return status;
 791	}
 792
 793	ac->ac_inode = alloc_inode;
 794	ac->ac_alloc_slot = slot;
 795
 796	fe = (struct ocfs2_dinode *) bh->b_data;
 797
 798	/* The bh was validated by the inode read inside
 799	 * ocfs2_inode_lock().  Any corruption is a code bug. */
 800	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
 801
 802	if (!(fe->i_flags & cpu_to_le32(OCFS2_CHAIN_FL))) {
 803		status = ocfs2_error(alloc_inode->i_sb,
 804				     "Invalid chain allocator %llu\n",
 805				     (unsigned long long)le64_to_cpu(fe->i_blkno));
 806		goto bail;
 807	}
 808
 809	free_bits = le32_to_cpu(fe->id1.bitmap1.i_total) -
 810		le32_to_cpu(fe->id1.bitmap1.i_used);
 811
 812	if (bits_wanted > free_bits) {
 813		/* cluster bitmap never grows */
 814		if (ocfs2_is_cluster_bitmap(alloc_inode)) {
 815			trace_ocfs2_reserve_suballoc_bits_nospc(bits_wanted,
 816								free_bits);
 817			status = -ENOSPC;
 818			goto bail;
 819		}
 820
 821		if (!(flags & ALLOC_NEW_GROUP)) {
 822			trace_ocfs2_reserve_suballoc_bits_no_new_group(
 823						slot, bits_wanted, free_bits);
 824			status = -ENOSPC;
 825			goto bail;
 826		}
 827
 828		status = ocfs2_block_group_alloc(osb, alloc_inode, bh,
 829						 ac->ac_max_block,
 830						 last_alloc_group, flags);
 831		if (status < 0) {
 832			if (status != -ENOSPC)
 833				mlog_errno(status);
 834			goto bail;
 835		}
 836		atomic_inc(&osb->alloc_stats.bg_extends);
 837
 838		/* You should never ask for this much metadata */
 839		BUG_ON(bits_wanted >
 840		       (le32_to_cpu(fe->id1.bitmap1.i_total)
 841			- le32_to_cpu(fe->id1.bitmap1.i_used)));
 842	}
 843
 844	get_bh(bh);
 845	ac->ac_bh = bh;
 846bail:
 847	brelse(bh);
 848
 849	if (status)
 850		mlog_errno(status);
 851	return status;
 852}
 853
 854static void ocfs2_init_inode_steal_slot(struct ocfs2_super *osb)
 855{
 856	spin_lock(&osb->osb_lock);
 857	osb->s_inode_steal_slot = OCFS2_INVALID_SLOT;
 858	spin_unlock(&osb->osb_lock);
 859	atomic_set(&osb->s_num_inodes_stolen, 0);
 860}
 861
 862static void ocfs2_init_meta_steal_slot(struct ocfs2_super *osb)
 863{
 864	spin_lock(&osb->osb_lock);
 865	osb->s_meta_steal_slot = OCFS2_INVALID_SLOT;
 866	spin_unlock(&osb->osb_lock);
 867	atomic_set(&osb->s_num_meta_stolen, 0);
 868}
 869
 870void ocfs2_init_steal_slots(struct ocfs2_super *osb)
 871{
 872	ocfs2_init_inode_steal_slot(osb);
 873	ocfs2_init_meta_steal_slot(osb);
 874}
 875
 876static void __ocfs2_set_steal_slot(struct ocfs2_super *osb, int slot, int type)
 877{
 878	spin_lock(&osb->osb_lock);
 879	if (type == INODE_ALLOC_SYSTEM_INODE)
 880		osb->s_inode_steal_slot = (u16)slot;
 881	else if (type == EXTENT_ALLOC_SYSTEM_INODE)
 882		osb->s_meta_steal_slot = (u16)slot;
 883	spin_unlock(&osb->osb_lock);
 884}
 885
 886static int __ocfs2_get_steal_slot(struct ocfs2_super *osb, int type)
 887{
 888	int slot = OCFS2_INVALID_SLOT;
 889
 890	spin_lock(&osb->osb_lock);
 891	if (type == INODE_ALLOC_SYSTEM_INODE)
 892		slot = osb->s_inode_steal_slot;
 893	else if (type == EXTENT_ALLOC_SYSTEM_INODE)
 894		slot = osb->s_meta_steal_slot;
 895	spin_unlock(&osb->osb_lock);
 896
 897	return slot;
 898}
 899
 900static int ocfs2_get_inode_steal_slot(struct ocfs2_super *osb)
 901{
 902	return __ocfs2_get_steal_slot(osb, INODE_ALLOC_SYSTEM_INODE);
 903}
 904
 905static int ocfs2_get_meta_steal_slot(struct ocfs2_super *osb)
 906{
 907	return __ocfs2_get_steal_slot(osb, EXTENT_ALLOC_SYSTEM_INODE);
 908}
 909
 910static int ocfs2_steal_resource(struct ocfs2_super *osb,
 911				struct ocfs2_alloc_context *ac,
 912				int type)
 913{
 914	int i, status = -ENOSPC;
 915	int slot = __ocfs2_get_steal_slot(osb, type);
 916
 917	/* Start to steal resource from the first slot after ours. */
 918	if (slot == OCFS2_INVALID_SLOT)
 919		slot = osb->slot_num + 1;
 920
 921	for (i = 0; i < osb->max_slots; i++, slot++) {
 922		if (slot == osb->max_slots)
 923			slot = 0;
 924
 925		if (slot == osb->slot_num)
 926			continue;
 927
 928		status = ocfs2_reserve_suballoc_bits(osb, ac,
 929						     type,
 930						     (u32)slot, NULL,
 931						     NOT_ALLOC_NEW_GROUP);
 932		if (status >= 0) {
 933			__ocfs2_set_steal_slot(osb, slot, type);
 934			break;
 935		}
 936
 937		ocfs2_free_ac_resource(ac);
 938	}
 939
 940	return status;
 941}
 942
 943static int ocfs2_steal_inode(struct ocfs2_super *osb,
 944			     struct ocfs2_alloc_context *ac)
 945{
 946	return ocfs2_steal_resource(osb, ac, INODE_ALLOC_SYSTEM_INODE);
 947}
 948
 949static int ocfs2_steal_meta(struct ocfs2_super *osb,
 950			    struct ocfs2_alloc_context *ac)
 951{
 952	return ocfs2_steal_resource(osb, ac, EXTENT_ALLOC_SYSTEM_INODE);
 953}
 954
 955int ocfs2_reserve_new_metadata_blocks(struct ocfs2_super *osb,
 956				      int blocks,
 957				      struct ocfs2_alloc_context **ac)
 958{
 959	int status;
 960	int slot = ocfs2_get_meta_steal_slot(osb);
 961
 962	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 963	if (!(*ac)) {
 964		status = -ENOMEM;
 965		mlog_errno(status);
 966		goto bail;
 967	}
 968
 969	(*ac)->ac_bits_wanted = blocks;
 970	(*ac)->ac_which = OCFS2_AC_USE_META;
 971	(*ac)->ac_group_search = ocfs2_block_group_search;
 972
 973	if (slot != OCFS2_INVALID_SLOT &&
 974		atomic_read(&osb->s_num_meta_stolen) < OCFS2_MAX_TO_STEAL)
 975		goto extent_steal;
 976
 977	atomic_set(&osb->s_num_meta_stolen, 0);
 978	status = ocfs2_reserve_suballoc_bits(osb, (*ac),
 979					     EXTENT_ALLOC_SYSTEM_INODE,
 980					     (u32)osb->slot_num, NULL,
 981					     ALLOC_GROUPS_FROM_GLOBAL|ALLOC_NEW_GROUP);
 982
 983
 984	if (status >= 0) {
 985		status = 0;
 986		if (slot != OCFS2_INVALID_SLOT)
 987			ocfs2_init_meta_steal_slot(osb);
 988		goto bail;
 989	} else if (status < 0 && status != -ENOSPC) {
 990		mlog_errno(status);
 991		goto bail;
 992	}
 993
 994	ocfs2_free_ac_resource(*ac);
 995
 996extent_steal:
 997	status = ocfs2_steal_meta(osb, *ac);
 998	atomic_inc(&osb->s_num_meta_stolen);
 999	if (status < 0) {
1000		if (status != -ENOSPC)
1001			mlog_errno(status);
1002		goto bail;
1003	}
1004
1005	status = 0;
1006bail:
1007	if ((status < 0) && *ac) {
1008		ocfs2_free_alloc_context(*ac);
1009		*ac = NULL;
1010	}
1011
1012	if (status)
1013		mlog_errno(status);
1014	return status;
1015}
1016
1017int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
1018			       struct ocfs2_extent_list *root_el,
1019			       struct ocfs2_alloc_context **ac)
1020{
1021	return ocfs2_reserve_new_metadata_blocks(osb,
1022					ocfs2_extend_meta_needed(root_el),
1023					ac);
1024}
1025
1026int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
1027			    struct ocfs2_alloc_context **ac)
1028{
1029	int status;
1030	int slot = ocfs2_get_inode_steal_slot(osb);
1031	u64 alloc_group;
1032
1033	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1034	if (!(*ac)) {
1035		status = -ENOMEM;
1036		mlog_errno(status);
1037		goto bail;
1038	}
1039
1040	(*ac)->ac_bits_wanted = 1;
1041	(*ac)->ac_which = OCFS2_AC_USE_INODE;
1042
1043	(*ac)->ac_group_search = ocfs2_block_group_search;
1044
1045	/*
1046	 * stat(2) can't handle i_ino > 32bits, so we tell the
1047	 * lower levels not to allocate us a block group past that
1048	 * limit.  The 'inode64' mount option avoids this behavior.
1049	 */
1050	if (!(osb->s_mount_opt & OCFS2_MOUNT_INODE64))
1051		(*ac)->ac_max_block = (u32)~0U;
1052
1053	/*
1054	 * slot is set when we successfully steal inode from other nodes.
1055	 * It is reset in 3 places:
1056	 * 1. when we flush the truncate log
1057	 * 2. when we complete local alloc recovery.
1058	 * 3. when we successfully allocate from our own slot.
1059	 * After it is set, we will go on stealing inodes until we find the
1060	 * need to check our slots to see whether there is some space for us.
1061	 */
1062	if (slot != OCFS2_INVALID_SLOT &&
1063	    atomic_read(&osb->s_num_inodes_stolen) < OCFS2_MAX_TO_STEAL)
1064		goto inode_steal;
1065
1066	atomic_set(&osb->s_num_inodes_stolen, 0);
1067	alloc_group = osb->osb_inode_alloc_group;
1068	status = ocfs2_reserve_suballoc_bits(osb, *ac,
1069					     INODE_ALLOC_SYSTEM_INODE,
1070					     (u32)osb->slot_num,
1071					     &alloc_group,
1072					     ALLOC_NEW_GROUP |
1073					     ALLOC_GROUPS_FROM_GLOBAL);
1074	if (status >= 0) {
1075		status = 0;
1076
1077		spin_lock(&osb->osb_lock);
1078		osb->osb_inode_alloc_group = alloc_group;
1079		spin_unlock(&osb->osb_lock);
1080		trace_ocfs2_reserve_new_inode_new_group(
1081			(unsigned long long)alloc_group);
1082
1083		/*
1084		 * Some inodes must be freed by us, so try to allocate
1085		 * from our own next time.
1086		 */
1087		if (slot != OCFS2_INVALID_SLOT)
1088			ocfs2_init_inode_steal_slot(osb);
1089		goto bail;
1090	} else if (status < 0 && status != -ENOSPC) {
1091		mlog_errno(status);
1092		goto bail;
1093	}
1094
1095	ocfs2_free_ac_resource(*ac);
1096
1097inode_steal:
1098	status = ocfs2_steal_inode(osb, *ac);
1099	atomic_inc(&osb->s_num_inodes_stolen);
1100	if (status < 0) {
1101		if (status != -ENOSPC)
1102			mlog_errno(status);
1103		goto bail;
1104	}
1105
1106	status = 0;
1107bail:
1108	if ((status < 0) && *ac) {
1109		ocfs2_free_alloc_context(*ac);
1110		*ac = NULL;
1111	}
1112
1113	if (status)
1114		mlog_errno(status);
1115	return status;
1116}
1117
1118/* local alloc code has to do the same thing, so rather than do this
1119 * twice.. */
1120int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
1121				      struct ocfs2_alloc_context *ac)
1122{
1123	int status;
1124
1125	ac->ac_which = OCFS2_AC_USE_MAIN;
1126	ac->ac_group_search = ocfs2_cluster_group_search;
1127
1128	status = ocfs2_reserve_suballoc_bits(osb, ac,
1129					     GLOBAL_BITMAP_SYSTEM_INODE,
1130					     OCFS2_INVALID_SLOT, NULL,
1131					     ALLOC_NEW_GROUP);
1132	if (status < 0 && status != -ENOSPC)
1133		mlog_errno(status);
 
 
1134
 
1135	return status;
1136}
1137
1138/* Callers don't need to care which bitmap (local alloc or main) to
1139 * use so we figure it out for them, but unfortunately this clutters
1140 * things a bit. */
1141static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
1142					     u32 bits_wanted, u64 max_block,
1143					     int flags,
1144					     struct ocfs2_alloc_context **ac)
1145{
1146	int status, ret = 0;
1147	int retried = 0;
1148
1149	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1150	if (!(*ac)) {
1151		status = -ENOMEM;
1152		mlog_errno(status);
1153		goto bail;
1154	}
1155
1156	(*ac)->ac_bits_wanted = bits_wanted;
1157	(*ac)->ac_max_block = max_block;
1158
1159	status = -ENOSPC;
1160	if (!(flags & ALLOC_GROUPS_FROM_GLOBAL) &&
1161	    ocfs2_alloc_should_use_local(osb, bits_wanted)) {
1162		status = ocfs2_reserve_local_alloc_bits(osb,
1163							bits_wanted,
1164							*ac);
1165		if ((status < 0) && (status != -ENOSPC)) {
1166			mlog_errno(status);
1167			goto bail;
1168		}
1169	}
1170
1171	if (status == -ENOSPC) {
1172retry:
1173		status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
1174		/* Retry if there is sufficient space cached in truncate log */
1175		if (status == -ENOSPC && !retried) {
1176			retried = 1;
1177			ocfs2_inode_unlock((*ac)->ac_inode, 1);
1178			inode_unlock((*ac)->ac_inode);
1179
1180			ret = ocfs2_try_to_free_truncate_log(osb, bits_wanted);
1181			if (ret == 1) {
1182				iput((*ac)->ac_inode);
1183				(*ac)->ac_inode = NULL;
1184				goto retry;
1185			}
1186
1187			if (ret < 0)
1188				mlog_errno(ret);
1189
1190			inode_lock((*ac)->ac_inode);
1191			ret = ocfs2_inode_lock((*ac)->ac_inode, NULL, 1);
1192			if (ret < 0) {
1193				mlog_errno(ret);
1194				inode_unlock((*ac)->ac_inode);
1195				iput((*ac)->ac_inode);
1196				(*ac)->ac_inode = NULL;
1197				goto bail;
1198			}
1199		}
1200		if (status < 0) {
1201			if (status != -ENOSPC)
1202				mlog_errno(status);
1203			goto bail;
1204		}
1205	}
1206
1207	status = 0;
1208bail:
1209	if ((status < 0) && *ac) {
1210		ocfs2_free_alloc_context(*ac);
1211		*ac = NULL;
1212	}
1213
1214	if (status)
1215		mlog_errno(status);
1216	return status;
1217}
1218
1219int ocfs2_reserve_clusters(struct ocfs2_super *osb,
1220			   u32 bits_wanted,
1221			   struct ocfs2_alloc_context **ac)
1222{
1223	return ocfs2_reserve_clusters_with_limit(osb, bits_wanted, 0,
1224						 ALLOC_NEW_GROUP, ac);
1225}
1226
1227/*
1228 * More or less lifted from ext3. I'll leave their description below:
1229 *
1230 * "For ext3 allocations, we must not reuse any blocks which are
1231 * allocated in the bitmap buffer's "last committed data" copy.  This
1232 * prevents deletes from freeing up the page for reuse until we have
1233 * committed the delete transaction.
1234 *
1235 * If we didn't do this, then deleting something and reallocating it as
1236 * data would allow the old block to be overwritten before the
1237 * transaction committed (because we force data to disk before commit).
1238 * This would lead to corruption if we crashed between overwriting the
1239 * data and committing the delete.
1240 *
1241 * @@@ We may want to make this allocation behaviour conditional on
1242 * data-writes at some point, and disable it for metadata allocations or
1243 * sync-data inodes."
1244 *
1245 * Note: OCFS2 already does this differently for metadata vs data
1246 * allocations, as those bitmaps are separate and undo access is never
1247 * called on a metadata group descriptor.
1248 */
1249static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
1250					 int nr)
1251{
1252	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1253	struct journal_head *jh;
1254	int ret;
1255
1256	if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
1257		return 0;
1258
1259	jh = jbd2_journal_grab_journal_head(bg_bh);
1260	if (!jh)
1261		return 1;
1262
1263	spin_lock(&jh->b_state_lock);
1264	bg = (struct ocfs2_group_desc *) jh->b_committed_data;
1265	if (bg)
1266		ret = !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
1267	else
1268		ret = 1;
1269	spin_unlock(&jh->b_state_lock);
1270	jbd2_journal_put_journal_head(jh);
1271
1272	return ret;
1273}
1274
1275static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
1276					     struct buffer_head *bg_bh,
1277					     unsigned int bits_wanted,
1278					     unsigned int total_bits,
1279					     struct ocfs2_suballoc_result *res)
1280{
1281	void *bitmap;
1282	u16 best_offset, best_size;
1283	int offset, start, found, status = 0;
1284	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1285
1286	/* Callers got this descriptor from
1287	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1288	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1289
1290	found = start = best_offset = best_size = 0;
1291	bitmap = bg->bg_bitmap;
1292
1293	while((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) != -1) {
1294		if (offset == total_bits)
1295			break;
1296
1297		if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
1298			/* We found a zero, but we can't use it as it
1299			 * hasn't been put to disk yet! */
1300			found = 0;
1301			start = offset + 1;
1302		} else if (offset == start) {
1303			/* we found a zero */
1304			found++;
1305			/* move start to the next bit to test */
1306			start++;
1307		} else {
1308			/* got a zero after some ones */
1309			found = 1;
1310			start = offset + 1;
1311		}
1312		if (found > best_size) {
1313			best_size = found;
1314			best_offset = start - found;
1315		}
1316		/* we got everything we needed */
1317		if (found == bits_wanted) {
1318			/* mlog(0, "Found it all!\n"); */
1319			break;
1320		}
1321	}
1322
1323	if (best_size) {
1324		res->sr_bit_offset = best_offset;
1325		res->sr_bits = best_size;
1326	} else {
1327		status = -ENOSPC;
1328		/* No error log here -- see the comment above
1329		 * ocfs2_test_bg_bit_allocatable */
1330	}
1331
1332	return status;
1333}
1334
1335int ocfs2_block_group_set_bits(handle_t *handle,
1336					     struct inode *alloc_inode,
1337					     struct ocfs2_group_desc *bg,
1338					     struct buffer_head *group_bh,
1339					     unsigned int bit_off,
1340					     unsigned int num_bits)
1341{
1342	int status;
1343	void *bitmap = bg->bg_bitmap;
1344	int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1345
1346	/* All callers get the descriptor via
1347	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1348	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1349	BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
1350
1351	trace_ocfs2_block_group_set_bits(bit_off, num_bits);
1352
1353	if (ocfs2_is_cluster_bitmap(alloc_inode))
1354		journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1355
1356	status = ocfs2_journal_access_gd(handle,
1357					 INODE_CACHE(alloc_inode),
1358					 group_bh,
1359					 journal_type);
1360	if (status < 0) {
1361		mlog_errno(status);
1362		goto bail;
1363	}
1364
1365	le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
1366	if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
1367		return ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit count %u but claims %u are freed. num_bits %d\n",
1368				   (unsigned long long)le64_to_cpu(bg->bg_blkno),
1369				   le16_to_cpu(bg->bg_bits),
1370				   le16_to_cpu(bg->bg_free_bits_count),
1371				   num_bits);
1372	}
1373	while(num_bits--)
1374		ocfs2_set_bit(bit_off++, bitmap);
1375
1376	ocfs2_journal_dirty(handle, group_bh);
1377
1378bail:
1379	return status;
1380}
1381
1382/* find the one with the most empty bits */
1383static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
1384{
1385	u16 curr, best;
1386
1387	BUG_ON(!cl->cl_next_free_rec);
1388
1389	best = curr = 0;
1390	while (curr < le16_to_cpu(cl->cl_next_free_rec)) {
1391		if (le32_to_cpu(cl->cl_recs[curr].c_free) >
1392		    le32_to_cpu(cl->cl_recs[best].c_free))
1393			best = curr;
1394		curr++;
1395	}
1396
1397	BUG_ON(best >= le16_to_cpu(cl->cl_next_free_rec));
1398	return best;
1399}
1400
1401static int ocfs2_relink_block_group(handle_t *handle,
1402				    struct inode *alloc_inode,
1403				    struct buffer_head *fe_bh,
1404				    struct buffer_head *bg_bh,
1405				    struct buffer_head *prev_bg_bh,
1406				    u16 chain)
1407{
1408	int status;
1409	/* there is a really tiny chance the journal calls could fail,
1410	 * but we wouldn't want inconsistent blocks in *any* case. */
1411	u64 bg_ptr, prev_bg_ptr;
1412	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
1413	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1414	struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
1415
1416	/* The caller got these descriptors from
1417	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1418	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1419	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(prev_bg));
1420
1421	trace_ocfs2_relink_block_group(
1422		(unsigned long long)le64_to_cpu(fe->i_blkno), chain,
1423		(unsigned long long)le64_to_cpu(bg->bg_blkno),
1424		(unsigned long long)le64_to_cpu(prev_bg->bg_blkno));
1425
1426	bg_ptr = le64_to_cpu(bg->bg_next_group);
1427	prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
1428
1429	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1430					 prev_bg_bh,
1431					 OCFS2_JOURNAL_ACCESS_WRITE);
1432	if (status < 0)
1433		goto out;
1434
1435	prev_bg->bg_next_group = bg->bg_next_group;
1436	ocfs2_journal_dirty(handle, prev_bg_bh);
1437
1438	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1439					 bg_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1440	if (status < 0)
1441		goto out_rollback_prev_bg;
1442
1443	bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
1444	ocfs2_journal_dirty(handle, bg_bh);
1445
1446	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
1447					 fe_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1448	if (status < 0)
1449		goto out_rollback_bg;
1450
1451	fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
1452	ocfs2_journal_dirty(handle, fe_bh);
1453
1454out:
1455	if (status < 0)
1456		mlog_errno(status);
1457	return status;
1458
1459out_rollback_bg:
1460	bg->bg_next_group = cpu_to_le64(bg_ptr);
1461out_rollback_prev_bg:
1462	prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
1463	goto out;
1464}
1465
1466static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
1467						     u32 wanted)
1468{
1469	return le16_to_cpu(bg->bg_free_bits_count) > wanted;
1470}
1471
1472/* return 0 on success, -ENOSPC to keep searching and any other < 0
1473 * value on error. */
1474static int ocfs2_cluster_group_search(struct inode *inode,
1475				      struct buffer_head *group_bh,
1476				      u32 bits_wanted, u32 min_bits,
1477				      u64 max_block,
1478				      struct ocfs2_suballoc_result *res)
1479{
1480	int search = -ENOSPC;
1481	int ret;
1482	u64 blkoff;
1483	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
1484	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1485	unsigned int max_bits, gd_cluster_off;
1486
1487	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1488
1489	if (gd->bg_free_bits_count) {
1490		max_bits = le16_to_cpu(gd->bg_bits);
1491
1492		/* Tail groups in cluster bitmaps which aren't cpg
1493		 * aligned are prone to partial extension by a failed
1494		 * fs resize. If the file system resize never got to
1495		 * update the dinode cluster count, then we don't want
1496		 * to trust any clusters past it, regardless of what
1497		 * the group descriptor says. */
1498		gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
1499							  le64_to_cpu(gd->bg_blkno));
1500		if ((gd_cluster_off + max_bits) >
1501		    OCFS2_I(inode)->ip_clusters) {
1502			max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
1503			trace_ocfs2_cluster_group_search_wrong_max_bits(
1504				(unsigned long long)le64_to_cpu(gd->bg_blkno),
1505				le16_to_cpu(gd->bg_bits),
1506				OCFS2_I(inode)->ip_clusters, max_bits);
1507		}
1508
1509		ret = ocfs2_block_group_find_clear_bits(osb,
1510							group_bh, bits_wanted,
1511							max_bits, res);
1512		if (ret)
1513			return ret;
1514
1515		if (max_block) {
1516			blkoff = ocfs2_clusters_to_blocks(inode->i_sb,
1517							  gd_cluster_off +
1518							  res->sr_bit_offset +
1519							  res->sr_bits);
1520			trace_ocfs2_cluster_group_search_max_block(
1521				(unsigned long long)blkoff,
1522				(unsigned long long)max_block);
1523			if (blkoff > max_block)
1524				return -ENOSPC;
1525		}
1526
1527		/* ocfs2_block_group_find_clear_bits() might
1528		 * return success, but we still want to return
1529		 * -ENOSPC unless it found the minimum number
1530		 * of bits. */
1531		if (min_bits <= res->sr_bits)
1532			search = 0; /* success */
1533		else if (res->sr_bits) {
1534			/*
1535			 * Don't show bits which we'll be returning
1536			 * for allocation to the local alloc bitmap.
1537			 */
1538			ocfs2_local_alloc_seen_free_bits(osb, res->sr_bits);
1539		}
1540	}
1541
1542	return search;
1543}
1544
1545static int ocfs2_block_group_search(struct inode *inode,
1546				    struct buffer_head *group_bh,
1547				    u32 bits_wanted, u32 min_bits,
1548				    u64 max_block,
1549				    struct ocfs2_suballoc_result *res)
1550{
1551	int ret = -ENOSPC;
1552	u64 blkoff;
1553	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
1554
1555	BUG_ON(min_bits != 1);
1556	BUG_ON(ocfs2_is_cluster_bitmap(inode));
1557
1558	if (bg->bg_free_bits_count) {
1559		ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1560							group_bh, bits_wanted,
1561							le16_to_cpu(bg->bg_bits),
1562							res);
1563		if (!ret && max_block) {
1564			blkoff = le64_to_cpu(bg->bg_blkno) +
1565				res->sr_bit_offset + res->sr_bits;
1566			trace_ocfs2_block_group_search_max_block(
1567				(unsigned long long)blkoff,
1568				(unsigned long long)max_block);
1569			if (blkoff > max_block)
1570				ret = -ENOSPC;
1571		}
1572	}
1573
1574	return ret;
1575}
1576
1577int ocfs2_alloc_dinode_update_counts(struct inode *inode,
1578				       handle_t *handle,
1579				       struct buffer_head *di_bh,
1580				       u32 num_bits,
1581				       u16 chain)
1582{
1583	int ret;
1584	u32 tmp_used;
1585	struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1586	struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &di->id2.i_chain;
1587
1588	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
1589				      OCFS2_JOURNAL_ACCESS_WRITE);
1590	if (ret < 0) {
1591		mlog_errno(ret);
1592		goto out;
1593	}
1594
1595	tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1596	di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
1597	le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
1598	ocfs2_journal_dirty(handle, di_bh);
1599
1600out:
1601	return ret;
1602}
1603
1604void ocfs2_rollback_alloc_dinode_counts(struct inode *inode,
1605				       struct buffer_head *di_bh,
1606				       u32 num_bits,
1607				       u16 chain)
1608{
1609	u32 tmp_used;
1610	struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1611	struct ocfs2_chain_list *cl;
1612
1613	cl = (struct ocfs2_chain_list *)&di->id2.i_chain;
1614	tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1615	di->id1.bitmap1.i_used = cpu_to_le32(tmp_used - num_bits);
1616	le32_add_cpu(&cl->cl_recs[chain].c_free, num_bits);
1617}
1618
1619static int ocfs2_bg_discontig_fix_by_rec(struct ocfs2_suballoc_result *res,
1620					 struct ocfs2_extent_rec *rec,
1621					 struct ocfs2_chain_list *cl)
1622{
1623	unsigned int bpc = le16_to_cpu(cl->cl_bpc);
1624	unsigned int bitoff = le32_to_cpu(rec->e_cpos) * bpc;
1625	unsigned int bitcount = le16_to_cpu(rec->e_leaf_clusters) * bpc;
1626
1627	if (res->sr_bit_offset < bitoff)
1628		return 0;
1629	if (res->sr_bit_offset >= (bitoff + bitcount))
1630		return 0;
1631	res->sr_blkno = le64_to_cpu(rec->e_blkno) +
1632		(res->sr_bit_offset - bitoff);
1633	if ((res->sr_bit_offset + res->sr_bits) > (bitoff + bitcount))
1634		res->sr_bits = (bitoff + bitcount) - res->sr_bit_offset;
1635	return 1;
1636}
1637
1638static void ocfs2_bg_discontig_fix_result(struct ocfs2_alloc_context *ac,
1639					  struct ocfs2_group_desc *bg,
1640					  struct ocfs2_suballoc_result *res)
1641{
1642	int i;
1643	u64 bg_blkno = res->sr_bg_blkno;  /* Save off */
1644	struct ocfs2_extent_rec *rec;
1645	struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1646	struct ocfs2_chain_list *cl = &di->id2.i_chain;
1647
1648	if (ocfs2_is_cluster_bitmap(ac->ac_inode)) {
1649		res->sr_blkno = 0;
1650		return;
1651	}
1652
1653	res->sr_blkno = res->sr_bg_blkno + res->sr_bit_offset;
1654	res->sr_bg_blkno = 0;  /* Clear it for contig block groups */
1655	if (!ocfs2_supports_discontig_bg(OCFS2_SB(ac->ac_inode->i_sb)) ||
1656	    !bg->bg_list.l_next_free_rec)
1657		return;
1658
1659	for (i = 0; i < le16_to_cpu(bg->bg_list.l_next_free_rec); i++) {
1660		rec = &bg->bg_list.l_recs[i];
1661		if (ocfs2_bg_discontig_fix_by_rec(res, rec, cl)) {
1662			res->sr_bg_blkno = bg_blkno;  /* Restore */
1663			break;
1664		}
1665	}
1666}
1667
1668static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
1669				  handle_t *handle,
1670				  u32 bits_wanted,
1671				  u32 min_bits,
1672				  struct ocfs2_suballoc_result *res,
1673				  u16 *bits_left)
1674{
1675	int ret;
1676	struct buffer_head *group_bh = NULL;
1677	struct ocfs2_group_desc *gd;
1678	struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1679	struct inode *alloc_inode = ac->ac_inode;
1680
1681	ret = ocfs2_read_group_descriptor(alloc_inode, di,
1682					  res->sr_bg_blkno, &group_bh);
1683	if (ret < 0) {
1684		mlog_errno(ret);
1685		return ret;
1686	}
1687
1688	gd = (struct ocfs2_group_desc *) group_bh->b_data;
1689	ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
1690				  ac->ac_max_block, res);
1691	if (ret < 0) {
1692		if (ret != -ENOSPC)
1693			mlog_errno(ret);
1694		goto out;
1695	}
1696
1697	if (!ret)
1698		ocfs2_bg_discontig_fix_result(ac, gd, res);
1699
1700	/*
1701	 * sr_bg_blkno might have been changed by
1702	 * ocfs2_bg_discontig_fix_result
1703	 */
1704	res->sr_bg_stable_blkno = group_bh->b_blocknr;
1705
1706	if (ac->ac_find_loc_only)
1707		goto out_loc_only;
1708
1709	ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
1710					       res->sr_bits,
1711					       le16_to_cpu(gd->bg_chain));
1712	if (ret < 0) {
1713		mlog_errno(ret);
1714		goto out;
1715	}
1716
1717	ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
1718					 res->sr_bit_offset, res->sr_bits);
1719	if (ret < 0) {
1720		ocfs2_rollback_alloc_dinode_counts(alloc_inode, ac->ac_bh,
1721					       res->sr_bits,
1722					       le16_to_cpu(gd->bg_chain));
1723		mlog_errno(ret);
1724	}
1725
1726out_loc_only:
1727	*bits_left = le16_to_cpu(gd->bg_free_bits_count);
1728
1729out:
1730	brelse(group_bh);
1731
1732	return ret;
1733}
1734
1735static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
1736			      handle_t *handle,
1737			      u32 bits_wanted,
1738			      u32 min_bits,
1739			      struct ocfs2_suballoc_result *res,
1740			      u16 *bits_left)
1741{
1742	int status;
1743	u16 chain;
1744	u64 next_group;
1745	struct inode *alloc_inode = ac->ac_inode;
1746	struct buffer_head *group_bh = NULL;
1747	struct buffer_head *prev_group_bh = NULL;
1748	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1749	struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1750	struct ocfs2_group_desc *bg;
1751
1752	chain = ac->ac_chain;
1753	trace_ocfs2_search_chain_begin(
1754		(unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
1755		bits_wanted, chain);
1756
1757	status = ocfs2_read_group_descriptor(alloc_inode, fe,
1758					     le64_to_cpu(cl->cl_recs[chain].c_blkno),
1759					     &group_bh);
1760	if (status < 0) {
1761		mlog_errno(status);
1762		goto bail;
1763	}
1764	bg = (struct ocfs2_group_desc *) group_bh->b_data;
1765
1766	status = -ENOSPC;
1767	/* for now, the chain search is a bit simplistic. We just use
1768	 * the 1st group with any empty bits. */
1769	while ((status = ac->ac_group_search(alloc_inode, group_bh,
1770					     bits_wanted, min_bits,
1771					     ac->ac_max_block,
1772					     res)) == -ENOSPC) {
1773		if (!bg->bg_next_group)
1774			break;
1775
1776		brelse(prev_group_bh);
1777		prev_group_bh = NULL;
1778
1779		next_group = le64_to_cpu(bg->bg_next_group);
1780		prev_group_bh = group_bh;
1781		group_bh = NULL;
1782		status = ocfs2_read_group_descriptor(alloc_inode, fe,
1783						     next_group, &group_bh);
1784		if (status < 0) {
1785			mlog_errno(status);
1786			goto bail;
1787		}
1788		bg = (struct ocfs2_group_desc *) group_bh->b_data;
1789	}
1790	if (status < 0) {
1791		if (status != -ENOSPC)
1792			mlog_errno(status);
1793		goto bail;
1794	}
1795
1796	trace_ocfs2_search_chain_succ(
1797		(unsigned long long)le64_to_cpu(bg->bg_blkno), res->sr_bits);
1798
1799	res->sr_bg_blkno = le64_to_cpu(bg->bg_blkno);
1800
1801	BUG_ON(res->sr_bits == 0);
1802	if (!status)
1803		ocfs2_bg_discontig_fix_result(ac, bg, res);
1804
1805	/*
1806	 * sr_bg_blkno might have been changed by
1807	 * ocfs2_bg_discontig_fix_result
1808	 */
1809	res->sr_bg_stable_blkno = group_bh->b_blocknr;
1810
1811	/*
1812	 * Keep track of previous block descriptor read. When
1813	 * we find a target, if we have read more than X
1814	 * number of descriptors, and the target is reasonably
1815	 * empty, relink him to top of his chain.
1816	 *
1817	 * We've read 0 extra blocks and only send one more to
1818	 * the transaction, yet the next guy to search has a
1819	 * much easier time.
1820	 *
1821	 * Do this *after* figuring out how many bits we're taking out
1822	 * of our target group.
1823	 */
1824	if (!ac->ac_disable_chain_relink &&
1825	    (prev_group_bh) &&
1826	    (ocfs2_block_group_reasonably_empty(bg, res->sr_bits))) {
1827		status = ocfs2_relink_block_group(handle, alloc_inode,
1828						  ac->ac_bh, group_bh,
1829						  prev_group_bh, chain);
1830		if (status < 0) {
1831			mlog_errno(status);
1832			goto bail;
1833		}
1834	}
1835
1836	if (ac->ac_find_loc_only)
1837		goto out_loc_only;
1838
1839	status = ocfs2_alloc_dinode_update_counts(alloc_inode, handle,
1840						  ac->ac_bh, res->sr_bits,
1841						  chain);
1842	if (status) {
1843		mlog_errno(status);
1844		goto bail;
1845	}
1846
1847	status = ocfs2_block_group_set_bits(handle,
1848					    alloc_inode,
1849					    bg,
1850					    group_bh,
1851					    res->sr_bit_offset,
1852					    res->sr_bits);
1853	if (status < 0) {
1854		ocfs2_rollback_alloc_dinode_counts(alloc_inode,
1855					ac->ac_bh, res->sr_bits, chain);
1856		mlog_errno(status);
1857		goto bail;
1858	}
1859
1860	trace_ocfs2_search_chain_end(
1861			(unsigned long long)le64_to_cpu(fe->i_blkno),
1862			res->sr_bits);
1863
1864out_loc_only:
1865	*bits_left = le16_to_cpu(bg->bg_free_bits_count);
1866bail:
1867	brelse(group_bh);
1868	brelse(prev_group_bh);
1869
1870	if (status)
1871		mlog_errno(status);
1872	return status;
1873}
1874
1875/* will give out up to bits_wanted contiguous bits. */
1876static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
1877				     handle_t *handle,
1878				     u32 bits_wanted,
1879				     u32 min_bits,
1880				     struct ocfs2_suballoc_result *res)
1881{
1882	int status;
1883	u16 victim, i;
1884	u16 bits_left = 0;
1885	u64 hint = ac->ac_last_group;
1886	struct ocfs2_chain_list *cl;
1887	struct ocfs2_dinode *fe;
1888
1889	BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1890	BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1891	BUG_ON(!ac->ac_bh);
1892
1893	fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1894
1895	/* The bh was validated by the inode read during
1896	 * ocfs2_reserve_suballoc_bits().  Any corruption is a code bug. */
1897	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
1898
1899	if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1900	    le32_to_cpu(fe->id1.bitmap1.i_total)) {
1901		status = ocfs2_error(ac->ac_inode->i_sb,
1902				     "Chain allocator dinode %llu has %u used bits but only %u total\n",
1903				     (unsigned long long)le64_to_cpu(fe->i_blkno),
1904				     le32_to_cpu(fe->id1.bitmap1.i_used),
1905				     le32_to_cpu(fe->id1.bitmap1.i_total));
1906		goto bail;
1907	}
1908
1909	res->sr_bg_blkno = hint;
1910	if (res->sr_bg_blkno) {
1911		/* Attempt to short-circuit the usual search mechanism
1912		 * by jumping straight to the most recently used
1913		 * allocation group. This helps us maintain some
1914		 * contiguousness across allocations. */
1915		status = ocfs2_search_one_group(ac, handle, bits_wanted,
1916						min_bits, res, &bits_left);
1917		if (!status)
1918			goto set_hint;
1919		if (status < 0 && status != -ENOSPC) {
1920			mlog_errno(status);
1921			goto bail;
1922		}
1923	}
1924
1925	cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1926
1927	victim = ocfs2_find_victim_chain(cl);
1928	ac->ac_chain = victim;
1929
1930	status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1931				    res, &bits_left);
1932	if (!status) {
1933		if (ocfs2_is_cluster_bitmap(ac->ac_inode))
1934			hint = res->sr_bg_blkno;
1935		else
1936			hint = ocfs2_group_from_res(res);
1937		goto set_hint;
1938	}
1939	if (status < 0 && status != -ENOSPC) {
1940		mlog_errno(status);
1941		goto bail;
1942	}
1943
1944	trace_ocfs2_claim_suballoc_bits(victim);
1945
1946	/* If we didn't pick a good victim, then just default to
1947	 * searching each chain in order. Don't allow chain relinking
1948	 * because we only calculate enough journal credits for one
1949	 * relink per alloc. */
1950	ac->ac_disable_chain_relink = 1;
1951	for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
1952		if (i == victim)
1953			continue;
1954		if (!cl->cl_recs[i].c_free)
1955			continue;
1956
1957		ac->ac_chain = i;
1958		status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1959					    res, &bits_left);
1960		if (!status) {
1961			hint = ocfs2_group_from_res(res);
1962			break;
1963		}
1964		if (status < 0 && status != -ENOSPC) {
1965			mlog_errno(status);
1966			goto bail;
1967		}
1968	}
1969
1970set_hint:
1971	if (status != -ENOSPC) {
1972		/* If the next search of this group is not likely to
1973		 * yield a suitable extent, then we reset the last
1974		 * group hint so as to not waste a disk read */
1975		if (bits_left < min_bits)
1976			ac->ac_last_group = 0;
1977		else
1978			ac->ac_last_group = hint;
1979	}
1980
1981bail:
1982	if (status)
1983		mlog_errno(status);
1984	return status;
1985}
1986
1987int ocfs2_claim_metadata(handle_t *handle,
1988			 struct ocfs2_alloc_context *ac,
1989			 u32 bits_wanted,
1990			 u64 *suballoc_loc,
1991			 u16 *suballoc_bit_start,
1992			 unsigned int *num_bits,
1993			 u64 *blkno_start)
1994{
1995	int status;
1996	struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
1997
1998	BUG_ON(!ac);
1999	BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
2000	BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
2001
2002	status = ocfs2_claim_suballoc_bits(ac,
2003					   handle,
2004					   bits_wanted,
2005					   1,
2006					   &res);
2007	if (status < 0) {
2008		mlog_errno(status);
2009		goto bail;
2010	}
2011	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2012
2013	*suballoc_loc = res.sr_bg_blkno;
2014	*suballoc_bit_start = res.sr_bit_offset;
2015	*blkno_start = res.sr_blkno;
2016	ac->ac_bits_given += res.sr_bits;
2017	*num_bits = res.sr_bits;
2018	status = 0;
2019bail:
2020	if (status)
2021		mlog_errno(status);
2022	return status;
2023}
2024
2025static void ocfs2_init_inode_ac_group(struct inode *dir,
2026				      struct buffer_head *parent_di_bh,
2027				      struct ocfs2_alloc_context *ac)
2028{
2029	struct ocfs2_dinode *di = (struct ocfs2_dinode *)parent_di_bh->b_data;
2030	/*
2031	 * Try to allocate inodes from some specific group.
2032	 *
2033	 * If the parent dir has recorded the last group used in allocation,
2034	 * cool, use it. Otherwise if we try to allocate new inode from the
2035	 * same slot the parent dir belongs to, use the same chunk.
2036	 *
2037	 * We are very careful here to avoid the mistake of setting
2038	 * ac_last_group to a group descriptor from a different (unlocked) slot.
2039	 */
2040	if (OCFS2_I(dir)->ip_last_used_group &&
2041	    OCFS2_I(dir)->ip_last_used_slot == ac->ac_alloc_slot)
2042		ac->ac_last_group = OCFS2_I(dir)->ip_last_used_group;
2043	else if (le16_to_cpu(di->i_suballoc_slot) == ac->ac_alloc_slot) {
2044		if (di->i_suballoc_loc)
2045			ac->ac_last_group = le64_to_cpu(di->i_suballoc_loc);
2046		else
2047			ac->ac_last_group = ocfs2_which_suballoc_group(
2048					le64_to_cpu(di->i_blkno),
2049					le16_to_cpu(di->i_suballoc_bit));
2050	}
2051}
2052
2053static inline void ocfs2_save_inode_ac_group(struct inode *dir,
2054					     struct ocfs2_alloc_context *ac)
2055{
2056	OCFS2_I(dir)->ip_last_used_group = ac->ac_last_group;
2057	OCFS2_I(dir)->ip_last_used_slot = ac->ac_alloc_slot;
2058}
2059
2060int ocfs2_find_new_inode_loc(struct inode *dir,
2061			     struct buffer_head *parent_fe_bh,
2062			     struct ocfs2_alloc_context *ac,
2063			     u64 *fe_blkno)
2064{
2065	int ret;
2066	handle_t *handle = NULL;
2067	struct ocfs2_suballoc_result *res;
2068
2069	BUG_ON(!ac);
2070	BUG_ON(ac->ac_bits_given != 0);
2071	BUG_ON(ac->ac_bits_wanted != 1);
2072	BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2073
2074	res = kzalloc(sizeof(*res), GFP_NOFS);
2075	if (res == NULL) {
2076		ret = -ENOMEM;
2077		mlog_errno(ret);
2078		goto out;
2079	}
2080
2081	ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2082
2083	/*
2084	 * The handle started here is for chain relink. Alternatively,
2085	 * we could just disable relink for these calls.
2086	 */
2087	handle = ocfs2_start_trans(OCFS2_SB(dir->i_sb), OCFS2_SUBALLOC_ALLOC);
2088	if (IS_ERR(handle)) {
2089		ret = PTR_ERR(handle);
2090		handle = NULL;
2091		mlog_errno(ret);
2092		goto out;
2093	}
2094
2095	/*
2096	 * This will instruct ocfs2_claim_suballoc_bits and
2097	 * ocfs2_search_one_group to search but save actual allocation
2098	 * for later.
2099	 */
2100	ac->ac_find_loc_only = 1;
2101
2102	ret = ocfs2_claim_suballoc_bits(ac, handle, 1, 1, res);
2103	if (ret < 0) {
2104		mlog_errno(ret);
2105		goto out;
2106	}
2107
2108	ac->ac_find_loc_priv = res;
2109	*fe_blkno = res->sr_blkno;
2110	ocfs2_update_inode_fsync_trans(handle, dir, 0);
2111out:
2112	if (handle)
2113		ocfs2_commit_trans(OCFS2_SB(dir->i_sb), handle);
2114
2115	if (ret)
2116		kfree(res);
2117
2118	return ret;
2119}
2120
2121int ocfs2_claim_new_inode_at_loc(handle_t *handle,
2122				 struct inode *dir,
2123				 struct ocfs2_alloc_context *ac,
2124				 u64 *suballoc_loc,
2125				 u16 *suballoc_bit,
2126				 u64 di_blkno)
2127{
2128	int ret;
2129	u16 chain;
2130	struct ocfs2_suballoc_result *res = ac->ac_find_loc_priv;
2131	struct buffer_head *bg_bh = NULL;
2132	struct ocfs2_group_desc *bg;
2133	struct ocfs2_dinode *di = (struct ocfs2_dinode *) ac->ac_bh->b_data;
2134
2135	/*
2136	 * Since di_blkno is being passed back in, we check for any
2137	 * inconsistencies which may have happened between
2138	 * calls. These are code bugs as di_blkno is not expected to
2139	 * change once returned from ocfs2_find_new_inode_loc()
2140	 */
2141	BUG_ON(res->sr_blkno != di_blkno);
2142
2143	ret = ocfs2_read_group_descriptor(ac->ac_inode, di,
2144					  res->sr_bg_stable_blkno, &bg_bh);
2145	if (ret) {
2146		mlog_errno(ret);
2147		goto out;
2148	}
2149
2150	bg = (struct ocfs2_group_desc *) bg_bh->b_data;
2151	chain = le16_to_cpu(bg->bg_chain);
2152
2153	ret = ocfs2_alloc_dinode_update_counts(ac->ac_inode, handle,
2154					       ac->ac_bh, res->sr_bits,
2155					       chain);
2156	if (ret) {
2157		mlog_errno(ret);
2158		goto out;
2159	}
2160
2161	ret = ocfs2_block_group_set_bits(handle,
2162					 ac->ac_inode,
2163					 bg,
2164					 bg_bh,
2165					 res->sr_bit_offset,
2166					 res->sr_bits);
2167	if (ret < 0) {
2168		ocfs2_rollback_alloc_dinode_counts(ac->ac_inode,
2169					       ac->ac_bh, res->sr_bits, chain);
2170		mlog_errno(ret);
2171		goto out;
2172	}
2173
2174	trace_ocfs2_claim_new_inode_at_loc((unsigned long long)di_blkno,
2175					   res->sr_bits);
2176
2177	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2178
2179	BUG_ON(res->sr_bits != 1);
2180
2181	*suballoc_loc = res->sr_bg_blkno;
2182	*suballoc_bit = res->sr_bit_offset;
2183	ac->ac_bits_given++;
2184	ocfs2_save_inode_ac_group(dir, ac);
2185
2186out:
2187	brelse(bg_bh);
2188
2189	return ret;
2190}
2191
2192int ocfs2_claim_new_inode(handle_t *handle,
2193			  struct inode *dir,
2194			  struct buffer_head *parent_fe_bh,
2195			  struct ocfs2_alloc_context *ac,
2196			  u64 *suballoc_loc,
2197			  u16 *suballoc_bit,
2198			  u64 *fe_blkno)
2199{
2200	int status;
2201	struct ocfs2_suballoc_result res;
2202
2203	BUG_ON(!ac);
2204	BUG_ON(ac->ac_bits_given != 0);
2205	BUG_ON(ac->ac_bits_wanted != 1);
2206	BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2207
2208	ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2209
2210	status = ocfs2_claim_suballoc_bits(ac,
2211					   handle,
2212					   1,
2213					   1,
2214					   &res);
2215	if (status < 0) {
2216		mlog_errno(status);
2217		goto bail;
2218	}
2219	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2220
2221	BUG_ON(res.sr_bits != 1);
2222
2223	*suballoc_loc = res.sr_bg_blkno;
2224	*suballoc_bit = res.sr_bit_offset;
2225	*fe_blkno = res.sr_blkno;
2226	ac->ac_bits_given++;
2227	ocfs2_save_inode_ac_group(dir, ac);
2228	status = 0;
2229bail:
2230	if (status)
2231		mlog_errno(status);
2232	return status;
2233}
2234
2235/* translate a group desc. blkno and it's bitmap offset into
2236 * disk cluster offset. */
2237static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
2238						   u64 bg_blkno,
2239						   u16 bg_bit_off)
2240{
2241	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2242	u32 cluster = 0;
2243
2244	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2245
2246	if (bg_blkno != osb->first_cluster_group_blkno)
2247		cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
2248	cluster += (u32) bg_bit_off;
2249	return cluster;
2250}
2251
2252/* given a cluster offset, calculate which block group it belongs to
2253 * and return that block offset. */
2254u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster)
2255{
2256	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2257	u32 group_no;
2258
2259	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2260
2261	group_no = cluster / osb->bitmap_cpg;
2262	if (!group_no)
2263		return osb->first_cluster_group_blkno;
2264	return ocfs2_clusters_to_blocks(inode->i_sb,
2265					group_no * osb->bitmap_cpg);
2266}
2267
2268/* given the block number of a cluster start, calculate which cluster
2269 * group and descriptor bitmap offset that corresponds to. */
2270static inline void ocfs2_block_to_cluster_group(struct inode *inode,
2271						u64 data_blkno,
2272						u64 *bg_blkno,
2273						u16 *bg_bit_off)
2274{
2275	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2276	u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
2277
2278	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2279
2280	*bg_blkno = ocfs2_which_cluster_group(inode,
2281					      data_cluster);
2282
2283	if (*bg_blkno == osb->first_cluster_group_blkno)
2284		*bg_bit_off = (u16) data_cluster;
2285	else
2286		*bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
2287							     data_blkno - *bg_blkno);
2288}
2289
2290/*
2291 * min_bits - minimum contiguous chunk from this total allocation we
2292 * can handle. set to what we asked for originally for a full
2293 * contig. allocation, set to '1' to indicate we can deal with extents
2294 * of any size.
2295 */
2296int __ocfs2_claim_clusters(handle_t *handle,
2297			   struct ocfs2_alloc_context *ac,
2298			   u32 min_clusters,
2299			   u32 max_clusters,
2300			   u32 *cluster_start,
2301			   u32 *num_clusters)
2302{
2303	int status;
2304	unsigned int bits_wanted = max_clusters;
2305	struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
2306	struct ocfs2_super *osb = OCFS2_SB(ac->ac_inode->i_sb);
2307
2308	BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
2309
2310	BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
2311	       && ac->ac_which != OCFS2_AC_USE_MAIN);
2312
2313	if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
2314		WARN_ON(min_clusters > 1);
2315
2316		status = ocfs2_claim_local_alloc_bits(osb,
2317						      handle,
2318						      ac,
2319						      bits_wanted,
2320						      cluster_start,
2321						      num_clusters);
2322		if (!status)
2323			atomic_inc(&osb->alloc_stats.local_data);
2324	} else {
2325		if (min_clusters > (osb->bitmap_cpg - 1)) {
2326			/* The only paths asking for contiguousness
2327			 * should know about this already. */
2328			mlog(ML_ERROR, "minimum allocation requested %u exceeds "
2329			     "group bitmap size %u!\n", min_clusters,
2330			     osb->bitmap_cpg);
2331			status = -ENOSPC;
2332			goto bail;
2333		}
2334		/* clamp the current request down to a realistic size. */
2335		if (bits_wanted > (osb->bitmap_cpg - 1))
2336			bits_wanted = osb->bitmap_cpg - 1;
2337
2338		status = ocfs2_claim_suballoc_bits(ac,
2339						   handle,
2340						   bits_wanted,
2341						   min_clusters,
2342						   &res);
2343		if (!status) {
2344			BUG_ON(res.sr_blkno); /* cluster alloc can't set */
2345			*cluster_start =
2346				ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
2347								 res.sr_bg_blkno,
2348								 res.sr_bit_offset);
2349			atomic_inc(&osb->alloc_stats.bitmap_data);
2350			*num_clusters = res.sr_bits;
2351		}
2352	}
2353	if (status < 0) {
2354		if (status != -ENOSPC)
2355			mlog_errno(status);
2356		goto bail;
2357	}
2358
2359	ac->ac_bits_given += *num_clusters;
2360
2361bail:
2362	if (status)
2363		mlog_errno(status);
2364	return status;
2365}
2366
2367int ocfs2_claim_clusters(handle_t *handle,
2368			 struct ocfs2_alloc_context *ac,
2369			 u32 min_clusters,
2370			 u32 *cluster_start,
2371			 u32 *num_clusters)
2372{
2373	unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
2374
2375	return __ocfs2_claim_clusters(handle, ac, min_clusters,
2376				      bits_wanted, cluster_start, num_clusters);
2377}
2378
2379static int ocfs2_block_group_clear_bits(handle_t *handle,
2380					struct inode *alloc_inode,
2381					struct ocfs2_group_desc *bg,
2382					struct buffer_head *group_bh,
2383					unsigned int bit_off,
2384					unsigned int num_bits,
2385					void (*undo_fn)(unsigned int bit,
2386							unsigned long *bmap))
2387{
2388	int status;
2389	unsigned int tmp;
2390	struct ocfs2_group_desc *undo_bg = NULL;
2391	struct journal_head *jh;
2392
2393	/* The caller got this descriptor from
2394	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
2395	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
2396
2397	trace_ocfs2_block_group_clear_bits(bit_off, num_bits);
2398
2399	BUG_ON(undo_fn && !ocfs2_is_cluster_bitmap(alloc_inode));
2400	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
2401					 group_bh,
2402					 undo_fn ?
2403					 OCFS2_JOURNAL_ACCESS_UNDO :
2404					 OCFS2_JOURNAL_ACCESS_WRITE);
2405	if (status < 0) {
2406		mlog_errno(status);
2407		goto bail;
2408	}
2409
2410	jh = bh2jh(group_bh);
2411	if (undo_fn) {
2412		spin_lock(&jh->b_state_lock);
2413		undo_bg = (struct ocfs2_group_desc *) jh->b_committed_data;
 
2414		BUG_ON(!undo_bg);
2415	}
2416
2417	tmp = num_bits;
2418	while(tmp--) {
2419		ocfs2_clear_bit((bit_off + tmp),
2420				(unsigned long *) bg->bg_bitmap);
2421		if (undo_fn)
2422			undo_fn(bit_off + tmp,
2423				(unsigned long *) undo_bg->bg_bitmap);
2424	}
2425	le16_add_cpu(&bg->bg_free_bits_count, num_bits);
2426	if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
2427		if (undo_fn)
2428			spin_unlock(&jh->b_state_lock);
2429		return ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit count %u but claims %u are freed. num_bits %d\n",
2430				   (unsigned long long)le64_to_cpu(bg->bg_blkno),
2431				   le16_to_cpu(bg->bg_bits),
2432				   le16_to_cpu(bg->bg_free_bits_count),
2433				   num_bits);
2434	}
2435
2436	if (undo_fn)
2437		spin_unlock(&jh->b_state_lock);
2438
2439	ocfs2_journal_dirty(handle, group_bh);
2440bail:
2441	return status;
2442}
2443
2444/*
2445 * expects the suballoc inode to already be locked.
2446 */
2447static int _ocfs2_free_suballoc_bits(handle_t *handle,
2448				     struct inode *alloc_inode,
2449				     struct buffer_head *alloc_bh,
2450				     unsigned int start_bit,
2451				     u64 bg_blkno,
2452				     unsigned int count,
2453				     void (*undo_fn)(unsigned int bit,
2454						     unsigned long *bitmap))
2455{
2456	int status = 0;
2457	u32 tmp_used;
2458	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
2459	struct ocfs2_chain_list *cl = &fe->id2.i_chain;
2460	struct buffer_head *group_bh = NULL;
2461	struct ocfs2_group_desc *group;
2462
2463	/* The alloc_bh comes from ocfs2_free_dinode() or
2464	 * ocfs2_free_clusters().  The callers have all locked the
2465	 * allocator and gotten alloc_bh from the lock call.  This
2466	 * validates the dinode buffer.  Any corruption that has happened
2467	 * is a code bug. */
2468	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
2469	BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
2470
2471	trace_ocfs2_free_suballoc_bits(
2472		(unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
2473		(unsigned long long)bg_blkno,
2474		start_bit, count);
2475
2476	status = ocfs2_read_group_descriptor(alloc_inode, fe, bg_blkno,
2477					     &group_bh);
2478	if (status < 0) {
2479		mlog_errno(status);
2480		goto bail;
2481	}
2482	group = (struct ocfs2_group_desc *) group_bh->b_data;
2483
2484	BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
2485
2486	status = ocfs2_block_group_clear_bits(handle, alloc_inode,
2487					      group, group_bh,
2488					      start_bit, count, undo_fn);
2489	if (status < 0) {
2490		mlog_errno(status);
2491		goto bail;
2492	}
2493
2494	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
2495					 alloc_bh, OCFS2_JOURNAL_ACCESS_WRITE);
2496	if (status < 0) {
2497		mlog_errno(status);
2498		ocfs2_block_group_set_bits(handle, alloc_inode, group, group_bh,
2499				start_bit, count);
2500		goto bail;
2501	}
2502
2503	le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
2504		     count);
2505	tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
2506	fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
2507	ocfs2_journal_dirty(handle, alloc_bh);
2508
2509bail:
2510	brelse(group_bh);
 
 
 
2511	return status;
2512}
2513
2514int ocfs2_free_suballoc_bits(handle_t *handle,
2515			     struct inode *alloc_inode,
2516			     struct buffer_head *alloc_bh,
2517			     unsigned int start_bit,
2518			     u64 bg_blkno,
2519			     unsigned int count)
2520{
2521	return _ocfs2_free_suballoc_bits(handle, alloc_inode, alloc_bh,
2522					 start_bit, bg_blkno, count, NULL);
2523}
2524
2525int ocfs2_free_dinode(handle_t *handle,
2526		      struct inode *inode_alloc_inode,
2527		      struct buffer_head *inode_alloc_bh,
2528		      struct ocfs2_dinode *di)
2529{
2530	u64 blk = le64_to_cpu(di->i_blkno);
2531	u16 bit = le16_to_cpu(di->i_suballoc_bit);
2532	u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
2533
2534	if (di->i_suballoc_loc)
2535		bg_blkno = le64_to_cpu(di->i_suballoc_loc);
2536	return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
2537					inode_alloc_bh, bit, bg_blkno, 1);
2538}
2539
2540static int _ocfs2_free_clusters(handle_t *handle,
2541				struct inode *bitmap_inode,
2542				struct buffer_head *bitmap_bh,
2543				u64 start_blk,
2544				unsigned int num_clusters,
2545				void (*undo_fn)(unsigned int bit,
2546						unsigned long *bitmap))
2547{
2548	int status;
2549	u16 bg_start_bit;
2550	u64 bg_blkno;
 
2551
2552	/* You can't ever have a contiguous set of clusters
2553	 * bigger than a block group bitmap so we never have to worry
2554	 * about looping on them.
2555	 * This is expensive. We can safely remove once this stuff has
2556	 * gotten tested really well. */
2557	BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb,
2558				ocfs2_blocks_to_clusters(bitmap_inode->i_sb,
2559							 start_blk)));
2560
 
2561
2562	ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
2563				     &bg_start_bit);
2564
2565	trace_ocfs2_free_clusters((unsigned long long)bg_blkno,
2566			(unsigned long long)start_blk,
2567			bg_start_bit, num_clusters);
2568
2569	status = _ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
2570					   bg_start_bit, bg_blkno,
2571					   num_clusters, undo_fn);
2572	if (status < 0) {
2573		mlog_errno(status);
2574		goto out;
2575	}
2576
2577	ocfs2_local_alloc_seen_free_bits(OCFS2_SB(bitmap_inode->i_sb),
2578					 num_clusters);
2579
2580out:
 
 
2581	return status;
2582}
2583
2584int ocfs2_free_clusters(handle_t *handle,
2585			struct inode *bitmap_inode,
2586			struct buffer_head *bitmap_bh,
2587			u64 start_blk,
2588			unsigned int num_clusters)
2589{
2590	return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2591				    start_blk, num_clusters,
2592				    _ocfs2_set_bit);
2593}
2594
2595/*
2596 * Give never-used clusters back to the global bitmap.  We don't need
2597 * to protect these bits in the undo buffer.
2598 */
2599int ocfs2_release_clusters(handle_t *handle,
2600			   struct inode *bitmap_inode,
2601			   struct buffer_head *bitmap_bh,
2602			   u64 start_blk,
2603			   unsigned int num_clusters)
2604{
2605	return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2606				    start_blk, num_clusters,
2607				    _ocfs2_clear_bit);
2608}
2609
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2610/*
2611 * For a given allocation, determine which allocators will need to be
2612 * accessed, and lock them, reserving the appropriate number of bits.
2613 *
2614 * Sparse file systems call this from ocfs2_write_begin_nolock()
2615 * and ocfs2_allocate_unwritten_extents().
2616 *
2617 * File systems which don't support holes call this from
2618 * ocfs2_extend_allocation().
2619 */
2620int ocfs2_lock_allocators(struct inode *inode,
2621			  struct ocfs2_extent_tree *et,
2622			  u32 clusters_to_add, u32 extents_to_split,
2623			  struct ocfs2_alloc_context **data_ac,
2624			  struct ocfs2_alloc_context **meta_ac)
2625{
2626	int ret = 0, num_free_extents;
2627	unsigned int max_recs_needed = clusters_to_add + 2 * extents_to_split;
2628	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2629
2630	*meta_ac = NULL;
2631	if (data_ac)
2632		*data_ac = NULL;
2633
2634	BUG_ON(clusters_to_add != 0 && data_ac == NULL);
2635
2636	num_free_extents = ocfs2_num_free_extents(et);
2637	if (num_free_extents < 0) {
2638		ret = num_free_extents;
2639		mlog_errno(ret);
2640		goto out;
2641	}
2642
2643	/*
2644	 * Sparse allocation file systems need to be more conservative
2645	 * with reserving room for expansion - the actual allocation
2646	 * happens while we've got a journal handle open so re-taking
2647	 * a cluster lock (because we ran out of room for another
2648	 * extent) will violate ordering rules.
2649	 *
2650	 * Most of the time we'll only be seeing this 1 cluster at a time
2651	 * anyway.
2652	 *
2653	 * Always lock for any unwritten extents - we might want to
2654	 * add blocks during a split.
2655	 */
2656	if (!num_free_extents ||
2657	    (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed)) {
2658		ret = ocfs2_reserve_new_metadata(osb, et->et_root_el, meta_ac);
2659		if (ret < 0) {
2660			if (ret != -ENOSPC)
2661				mlog_errno(ret);
2662			goto out;
2663		}
2664	}
2665
2666	if (clusters_to_add == 0)
2667		goto out;
2668
2669	ret = ocfs2_reserve_clusters(osb, clusters_to_add, data_ac);
2670	if (ret < 0) {
2671		if (ret != -ENOSPC)
2672			mlog_errno(ret);
2673		goto out;
2674	}
2675
2676out:
2677	if (ret) {
2678		if (*meta_ac) {
2679			ocfs2_free_alloc_context(*meta_ac);
2680			*meta_ac = NULL;
2681		}
2682
2683		/*
2684		 * We cannot have an error and a non null *data_ac.
2685		 */
2686	}
2687
2688	return ret;
2689}
2690
2691/*
2692 * Read the inode specified by blkno to get suballoc_slot and
2693 * suballoc_bit.
2694 */
2695static int ocfs2_get_suballoc_slot_bit(struct ocfs2_super *osb, u64 blkno,
2696				       u16 *suballoc_slot, u64 *group_blkno,
2697				       u16 *suballoc_bit)
2698{
2699	int status;
2700	struct buffer_head *inode_bh = NULL;
2701	struct ocfs2_dinode *inode_fe;
2702
2703	trace_ocfs2_get_suballoc_slot_bit((unsigned long long)blkno);
2704
2705	/* dirty read disk */
2706	status = ocfs2_read_blocks_sync(osb, blkno, 1, &inode_bh);
2707	if (status < 0) {
2708		mlog(ML_ERROR, "read block %llu failed %d\n",
2709		     (unsigned long long)blkno, status);
2710		goto bail;
2711	}
2712
2713	inode_fe = (struct ocfs2_dinode *) inode_bh->b_data;
2714	if (!OCFS2_IS_VALID_DINODE(inode_fe)) {
2715		mlog(ML_ERROR, "invalid inode %llu requested\n",
2716		     (unsigned long long)blkno);
2717		status = -EINVAL;
2718		goto bail;
2719	}
2720
2721	if (le16_to_cpu(inode_fe->i_suballoc_slot) != (u16)OCFS2_INVALID_SLOT &&
2722	    (u32)le16_to_cpu(inode_fe->i_suballoc_slot) > osb->max_slots - 1) {
2723		mlog(ML_ERROR, "inode %llu has invalid suballoc slot %u\n",
2724		     (unsigned long long)blkno,
2725		     (u32)le16_to_cpu(inode_fe->i_suballoc_slot));
2726		status = -EINVAL;
2727		goto bail;
2728	}
2729
2730	if (suballoc_slot)
2731		*suballoc_slot = le16_to_cpu(inode_fe->i_suballoc_slot);
2732	if (suballoc_bit)
2733		*suballoc_bit = le16_to_cpu(inode_fe->i_suballoc_bit);
2734	if (group_blkno)
2735		*group_blkno = le64_to_cpu(inode_fe->i_suballoc_loc);
2736
2737bail:
2738	brelse(inode_bh);
2739
2740	if (status)
2741		mlog_errno(status);
2742	return status;
2743}
2744
2745/*
2746 * test whether bit is SET in allocator bitmap or not.  on success, 0
2747 * is returned and *res is 1 for SET; 0 otherwise.  when fails, errno
2748 * is returned and *res is meaningless.  Call this after you have
2749 * cluster locked against suballoc, or you may get a result based on
2750 * non-up2date contents
2751 */
2752static int ocfs2_test_suballoc_bit(struct ocfs2_super *osb,
2753				   struct inode *suballoc,
2754				   struct buffer_head *alloc_bh,
2755				   u64 group_blkno, u64 blkno,
2756				   u16 bit, int *res)
2757{
2758	struct ocfs2_dinode *alloc_di;
2759	struct ocfs2_group_desc *group;
2760	struct buffer_head *group_bh = NULL;
2761	u64 bg_blkno;
2762	int status;
2763
2764	trace_ocfs2_test_suballoc_bit((unsigned long long)blkno,
2765				      (unsigned int)bit);
2766
2767	alloc_di = (struct ocfs2_dinode *)alloc_bh->b_data;
2768	if ((bit + 1) > ocfs2_bits_per_group(&alloc_di->id2.i_chain)) {
2769		mlog(ML_ERROR, "suballoc bit %u out of range of %u\n",
2770		     (unsigned int)bit,
2771		     ocfs2_bits_per_group(&alloc_di->id2.i_chain));
2772		status = -EINVAL;
2773		goto bail;
2774	}
2775
2776	bg_blkno = group_blkno ? group_blkno :
2777		   ocfs2_which_suballoc_group(blkno, bit);
2778	status = ocfs2_read_group_descriptor(suballoc, alloc_di, bg_blkno,
2779					     &group_bh);
2780	if (status < 0) {
2781		mlog(ML_ERROR, "read group %llu failed %d\n",
2782		     (unsigned long long)bg_blkno, status);
2783		goto bail;
2784	}
2785
2786	group = (struct ocfs2_group_desc *) group_bh->b_data;
2787	*res = ocfs2_test_bit(bit, (unsigned long *)group->bg_bitmap);
2788
2789bail:
2790	brelse(group_bh);
2791
2792	if (status)
2793		mlog_errno(status);
2794	return status;
2795}
2796
2797/*
2798 * Test if the bit representing this inode (blkno) is set in the
2799 * suballocator.
2800 *
2801 * On success, 0 is returned and *res is 1 for SET; 0 otherwise.
2802 *
2803 * In the event of failure, a negative value is returned and *res is
2804 * meaningless.
2805 *
2806 * Callers must make sure to hold nfs_sync_lock to prevent
2807 * ocfs2_delete_inode() on another node from accessing the same
2808 * suballocator concurrently.
2809 */
2810int ocfs2_test_inode_bit(struct ocfs2_super *osb, u64 blkno, int *res)
2811{
2812	int status;
2813	u64 group_blkno = 0;
2814	u16 suballoc_bit = 0, suballoc_slot = 0;
2815	struct inode *inode_alloc_inode;
2816	struct buffer_head *alloc_bh = NULL;
2817
2818	trace_ocfs2_test_inode_bit((unsigned long long)blkno);
2819
2820	status = ocfs2_get_suballoc_slot_bit(osb, blkno, &suballoc_slot,
2821					     &group_blkno, &suballoc_bit);
2822	if (status < 0) {
2823		mlog(ML_ERROR, "get alloc slot and bit failed %d\n", status);
2824		goto bail;
2825	}
2826
2827	if (suballoc_slot == (u16)OCFS2_INVALID_SLOT)
2828		inode_alloc_inode = ocfs2_get_system_file_inode(osb,
2829			GLOBAL_INODE_ALLOC_SYSTEM_INODE, suballoc_slot);
2830	else
2831		inode_alloc_inode = ocfs2_get_system_file_inode(osb,
2832			INODE_ALLOC_SYSTEM_INODE, suballoc_slot);
2833	if (!inode_alloc_inode) {
2834		/* the error code could be inaccurate, but we are not able to
2835		 * get the correct one. */
2836		status = -EINVAL;
2837		mlog(ML_ERROR, "unable to get alloc inode in slot %u\n",
2838		     (u32)suballoc_slot);
2839		goto bail;
2840	}
2841
2842	inode_lock(inode_alloc_inode);
2843	status = ocfs2_inode_lock(inode_alloc_inode, &alloc_bh, 0);
2844	if (status < 0) {
2845		inode_unlock(inode_alloc_inode);
2846		iput(inode_alloc_inode);
2847		mlog(ML_ERROR, "lock on alloc inode on slot %u failed %d\n",
2848		     (u32)suballoc_slot, status);
2849		goto bail;
2850	}
2851
2852	status = ocfs2_test_suballoc_bit(osb, inode_alloc_inode, alloc_bh,
2853					 group_blkno, blkno, suballoc_bit, res);
2854	if (status < 0)
2855		mlog(ML_ERROR, "test suballoc bit failed %d\n", status);
2856
2857	ocfs2_inode_unlock(inode_alloc_inode, 0);
2858	inode_unlock(inode_alloc_inode);
2859
2860	iput(inode_alloc_inode);
2861	brelse(alloc_bh);
2862bail:
2863	if (status)
2864		mlog_errno(status);
2865	return status;
2866}
v4.10.11
   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, ret = 0;
1168	int retried = 0;
1169
1170	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1171	if (!(*ac)) {
1172		status = -ENOMEM;
1173		mlog_errno(status);
1174		goto bail;
1175	}
1176
1177	(*ac)->ac_bits_wanted = bits_wanted;
1178	(*ac)->ac_max_block = max_block;
1179
1180	status = -ENOSPC;
1181	if (!(flags & ALLOC_GROUPS_FROM_GLOBAL) &&
1182	    ocfs2_alloc_should_use_local(osb, bits_wanted)) {
1183		status = ocfs2_reserve_local_alloc_bits(osb,
1184							bits_wanted,
1185							*ac);
1186		if ((status < 0) && (status != -ENOSPC)) {
1187			mlog_errno(status);
1188			goto bail;
1189		}
1190	}
1191
1192	if (status == -ENOSPC) {
1193retry:
1194		status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
1195		/* Retry if there is sufficient space cached in truncate log */
1196		if (status == -ENOSPC && !retried) {
1197			retried = 1;
1198			ocfs2_inode_unlock((*ac)->ac_inode, 1);
1199			inode_unlock((*ac)->ac_inode);
1200
1201			ret = ocfs2_try_to_free_truncate_log(osb, bits_wanted);
1202			if (ret == 1) {
1203				iput((*ac)->ac_inode);
1204				(*ac)->ac_inode = NULL;
1205				goto retry;
1206			}
1207
1208			if (ret < 0)
1209				mlog_errno(ret);
1210
1211			inode_lock((*ac)->ac_inode);
1212			ret = ocfs2_inode_lock((*ac)->ac_inode, NULL, 1);
1213			if (ret < 0) {
1214				mlog_errno(ret);
1215				inode_unlock((*ac)->ac_inode);
1216				iput((*ac)->ac_inode);
1217				(*ac)->ac_inode = NULL;
1218				goto bail;
1219			}
1220		}
1221		if (status < 0) {
1222			if (status != -ENOSPC)
1223				mlog_errno(status);
1224			goto bail;
1225		}
1226	}
1227
1228	status = 0;
1229bail:
1230	if ((status < 0) && *ac) {
1231		ocfs2_free_alloc_context(*ac);
1232		*ac = NULL;
1233	}
1234
1235	if (status)
1236		mlog_errno(status);
1237	return status;
1238}
1239
1240int ocfs2_reserve_clusters(struct ocfs2_super *osb,
1241			   u32 bits_wanted,
1242			   struct ocfs2_alloc_context **ac)
1243{
1244	return ocfs2_reserve_clusters_with_limit(osb, bits_wanted, 0,
1245						 ALLOC_NEW_GROUP, ac);
1246}
1247
1248/*
1249 * More or less lifted from ext3. I'll leave their description below:
1250 *
1251 * "For ext3 allocations, we must not reuse any blocks which are
1252 * allocated in the bitmap buffer's "last committed data" copy.  This
1253 * prevents deletes from freeing up the page for reuse until we have
1254 * committed the delete transaction.
1255 *
1256 * If we didn't do this, then deleting something and reallocating it as
1257 * data would allow the old block to be overwritten before the
1258 * transaction committed (because we force data to disk before commit).
1259 * This would lead to corruption if we crashed between overwriting the
1260 * data and committing the delete.
1261 *
1262 * @@@ We may want to make this allocation behaviour conditional on
1263 * data-writes at some point, and disable it for metadata allocations or
1264 * sync-data inodes."
1265 *
1266 * Note: OCFS2 already does this differently for metadata vs data
1267 * allocations, as those bitmaps are separate and undo access is never
1268 * called on a metadata group descriptor.
1269 */
1270static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
1271					 int nr)
1272{
1273	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 
1274	int ret;
1275
1276	if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
1277		return 0;
1278
1279	if (!buffer_jbd(bg_bh))
 
1280		return 1;
1281
1282	jbd_lock_bh_state(bg_bh);
1283	bg = (struct ocfs2_group_desc *) bh2jh(bg_bh)->b_committed_data;
1284	if (bg)
1285		ret = !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
1286	else
1287		ret = 1;
1288	jbd_unlock_bh_state(bg_bh);
 
1289
1290	return ret;
1291}
1292
1293static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
1294					     struct buffer_head *bg_bh,
1295					     unsigned int bits_wanted,
1296					     unsigned int total_bits,
1297					     struct ocfs2_suballoc_result *res)
1298{
1299	void *bitmap;
1300	u16 best_offset, best_size;
1301	int offset, start, found, status = 0;
1302	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1303
1304	/* Callers got this descriptor from
1305	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1306	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1307
1308	found = start = best_offset = best_size = 0;
1309	bitmap = bg->bg_bitmap;
1310
1311	while((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) != -1) {
1312		if (offset == total_bits)
1313			break;
1314
1315		if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
1316			/* We found a zero, but we can't use it as it
1317			 * hasn't been put to disk yet! */
1318			found = 0;
1319			start = offset + 1;
1320		} else if (offset == start) {
1321			/* we found a zero */
1322			found++;
1323			/* move start to the next bit to test */
1324			start++;
1325		} else {
1326			/* got a zero after some ones */
1327			found = 1;
1328			start = offset + 1;
1329		}
1330		if (found > best_size) {
1331			best_size = found;
1332			best_offset = start - found;
1333		}
1334		/* we got everything we needed */
1335		if (found == bits_wanted) {
1336			/* mlog(0, "Found it all!\n"); */
1337			break;
1338		}
1339	}
1340
1341	if (best_size) {
1342		res->sr_bit_offset = best_offset;
1343		res->sr_bits = best_size;
1344	} else {
1345		status = -ENOSPC;
1346		/* No error log here -- see the comment above
1347		 * ocfs2_test_bg_bit_allocatable */
1348	}
1349
1350	return status;
1351}
1352
1353int ocfs2_block_group_set_bits(handle_t *handle,
1354					     struct inode *alloc_inode,
1355					     struct ocfs2_group_desc *bg,
1356					     struct buffer_head *group_bh,
1357					     unsigned int bit_off,
1358					     unsigned int num_bits)
1359{
1360	int status;
1361	void *bitmap = bg->bg_bitmap;
1362	int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1363
1364	/* All callers get the descriptor via
1365	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1366	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1367	BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
1368
1369	trace_ocfs2_block_group_set_bits(bit_off, num_bits);
1370
1371	if (ocfs2_is_cluster_bitmap(alloc_inode))
1372		journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1373
1374	status = ocfs2_journal_access_gd(handle,
1375					 INODE_CACHE(alloc_inode),
1376					 group_bh,
1377					 journal_type);
1378	if (status < 0) {
1379		mlog_errno(status);
1380		goto bail;
1381	}
1382
1383	le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
1384	if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
1385		return ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit count %u but claims %u are freed. num_bits %d\n",
1386				   (unsigned long long)le64_to_cpu(bg->bg_blkno),
1387				   le16_to_cpu(bg->bg_bits),
1388				   le16_to_cpu(bg->bg_free_bits_count),
1389				   num_bits);
1390	}
1391	while(num_bits--)
1392		ocfs2_set_bit(bit_off++, bitmap);
1393
1394	ocfs2_journal_dirty(handle, group_bh);
1395
1396bail:
1397	return status;
1398}
1399
1400/* find the one with the most empty bits */
1401static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
1402{
1403	u16 curr, best;
1404
1405	BUG_ON(!cl->cl_next_free_rec);
1406
1407	best = curr = 0;
1408	while (curr < le16_to_cpu(cl->cl_next_free_rec)) {
1409		if (le32_to_cpu(cl->cl_recs[curr].c_free) >
1410		    le32_to_cpu(cl->cl_recs[best].c_free))
1411			best = curr;
1412		curr++;
1413	}
1414
1415	BUG_ON(best >= le16_to_cpu(cl->cl_next_free_rec));
1416	return best;
1417}
1418
1419static int ocfs2_relink_block_group(handle_t *handle,
1420				    struct inode *alloc_inode,
1421				    struct buffer_head *fe_bh,
1422				    struct buffer_head *bg_bh,
1423				    struct buffer_head *prev_bg_bh,
1424				    u16 chain)
1425{
1426	int status;
1427	/* there is a really tiny chance the journal calls could fail,
1428	 * but we wouldn't want inconsistent blocks in *any* case. */
1429	u64 bg_ptr, prev_bg_ptr;
1430	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
1431	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1432	struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
1433
1434	/* The caller got these descriptors from
1435	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1436	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1437	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(prev_bg));
1438
1439	trace_ocfs2_relink_block_group(
1440		(unsigned long long)le64_to_cpu(fe->i_blkno), chain,
1441		(unsigned long long)le64_to_cpu(bg->bg_blkno),
1442		(unsigned long long)le64_to_cpu(prev_bg->bg_blkno));
1443
1444	bg_ptr = le64_to_cpu(bg->bg_next_group);
1445	prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
1446
1447	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1448					 prev_bg_bh,
1449					 OCFS2_JOURNAL_ACCESS_WRITE);
1450	if (status < 0)
1451		goto out;
1452
1453	prev_bg->bg_next_group = bg->bg_next_group;
1454	ocfs2_journal_dirty(handle, prev_bg_bh);
1455
1456	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1457					 bg_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1458	if (status < 0)
1459		goto out_rollback_prev_bg;
1460
1461	bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
1462	ocfs2_journal_dirty(handle, bg_bh);
1463
1464	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
1465					 fe_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1466	if (status < 0)
1467		goto out_rollback_bg;
1468
1469	fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
1470	ocfs2_journal_dirty(handle, fe_bh);
1471
1472out:
1473	if (status < 0)
1474		mlog_errno(status);
1475	return status;
1476
1477out_rollback_bg:
1478	bg->bg_next_group = cpu_to_le64(bg_ptr);
1479out_rollback_prev_bg:
1480	prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
1481	goto out;
1482}
1483
1484static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
1485						     u32 wanted)
1486{
1487	return le16_to_cpu(bg->bg_free_bits_count) > wanted;
1488}
1489
1490/* return 0 on success, -ENOSPC to keep searching and any other < 0
1491 * value on error. */
1492static int ocfs2_cluster_group_search(struct inode *inode,
1493				      struct buffer_head *group_bh,
1494				      u32 bits_wanted, u32 min_bits,
1495				      u64 max_block,
1496				      struct ocfs2_suballoc_result *res)
1497{
1498	int search = -ENOSPC;
1499	int ret;
1500	u64 blkoff;
1501	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
1502	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1503	unsigned int max_bits, gd_cluster_off;
1504
1505	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1506
1507	if (gd->bg_free_bits_count) {
1508		max_bits = le16_to_cpu(gd->bg_bits);
1509
1510		/* Tail groups in cluster bitmaps which aren't cpg
1511		 * aligned are prone to partial extension by a failed
1512		 * fs resize. If the file system resize never got to
1513		 * update the dinode cluster count, then we don't want
1514		 * to trust any clusters past it, regardless of what
1515		 * the group descriptor says. */
1516		gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
1517							  le64_to_cpu(gd->bg_blkno));
1518		if ((gd_cluster_off + max_bits) >
1519		    OCFS2_I(inode)->ip_clusters) {
1520			max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
1521			trace_ocfs2_cluster_group_search_wrong_max_bits(
1522				(unsigned long long)le64_to_cpu(gd->bg_blkno),
1523				le16_to_cpu(gd->bg_bits),
1524				OCFS2_I(inode)->ip_clusters, max_bits);
1525		}
1526
1527		ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1528							group_bh, bits_wanted,
1529							max_bits, res);
1530		if (ret)
1531			return ret;
1532
1533		if (max_block) {
1534			blkoff = ocfs2_clusters_to_blocks(inode->i_sb,
1535							  gd_cluster_off +
1536							  res->sr_bit_offset +
1537							  res->sr_bits);
1538			trace_ocfs2_cluster_group_search_max_block(
1539				(unsigned long long)blkoff,
1540				(unsigned long long)max_block);
1541			if (blkoff > max_block)
1542				return -ENOSPC;
1543		}
1544
1545		/* ocfs2_block_group_find_clear_bits() might
1546		 * return success, but we still want to return
1547		 * -ENOSPC unless it found the minimum number
1548		 * of bits. */
1549		if (min_bits <= res->sr_bits)
1550			search = 0; /* success */
1551		else if (res->sr_bits) {
1552			/*
1553			 * Don't show bits which we'll be returning
1554			 * for allocation to the local alloc bitmap.
1555			 */
1556			ocfs2_local_alloc_seen_free_bits(osb, res->sr_bits);
1557		}
1558	}
1559
1560	return search;
1561}
1562
1563static int ocfs2_block_group_search(struct inode *inode,
1564				    struct buffer_head *group_bh,
1565				    u32 bits_wanted, u32 min_bits,
1566				    u64 max_block,
1567				    struct ocfs2_suballoc_result *res)
1568{
1569	int ret = -ENOSPC;
1570	u64 blkoff;
1571	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
1572
1573	BUG_ON(min_bits != 1);
1574	BUG_ON(ocfs2_is_cluster_bitmap(inode));
1575
1576	if (bg->bg_free_bits_count) {
1577		ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1578							group_bh, bits_wanted,
1579							le16_to_cpu(bg->bg_bits),
1580							res);
1581		if (!ret && max_block) {
1582			blkoff = le64_to_cpu(bg->bg_blkno) +
1583				res->sr_bit_offset + res->sr_bits;
1584			trace_ocfs2_block_group_search_max_block(
1585				(unsigned long long)blkoff,
1586				(unsigned long long)max_block);
1587			if (blkoff > max_block)
1588				ret = -ENOSPC;
1589		}
1590	}
1591
1592	return ret;
1593}
1594
1595int ocfs2_alloc_dinode_update_counts(struct inode *inode,
1596				       handle_t *handle,
1597				       struct buffer_head *di_bh,
1598				       u32 num_bits,
1599				       u16 chain)
1600{
1601	int ret;
1602	u32 tmp_used;
1603	struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1604	struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &di->id2.i_chain;
1605
1606	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
1607				      OCFS2_JOURNAL_ACCESS_WRITE);
1608	if (ret < 0) {
1609		mlog_errno(ret);
1610		goto out;
1611	}
1612
1613	tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1614	di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
1615	le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
1616	ocfs2_journal_dirty(handle, di_bh);
1617
1618out:
1619	return ret;
1620}
1621
1622void ocfs2_rollback_alloc_dinode_counts(struct inode *inode,
1623				       struct buffer_head *di_bh,
1624				       u32 num_bits,
1625				       u16 chain)
1626{
1627	u32 tmp_used;
1628	struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1629	struct ocfs2_chain_list *cl;
1630
1631	cl = (struct ocfs2_chain_list *)&di->id2.i_chain;
1632	tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1633	di->id1.bitmap1.i_used = cpu_to_le32(tmp_used - num_bits);
1634	le32_add_cpu(&cl->cl_recs[chain].c_free, num_bits);
1635}
1636
1637static int ocfs2_bg_discontig_fix_by_rec(struct ocfs2_suballoc_result *res,
1638					 struct ocfs2_extent_rec *rec,
1639					 struct ocfs2_chain_list *cl)
1640{
1641	unsigned int bpc = le16_to_cpu(cl->cl_bpc);
1642	unsigned int bitoff = le32_to_cpu(rec->e_cpos) * bpc;
1643	unsigned int bitcount = le16_to_cpu(rec->e_leaf_clusters) * bpc;
1644
1645	if (res->sr_bit_offset < bitoff)
1646		return 0;
1647	if (res->sr_bit_offset >= (bitoff + bitcount))
1648		return 0;
1649	res->sr_blkno = le64_to_cpu(rec->e_blkno) +
1650		(res->sr_bit_offset - bitoff);
1651	if ((res->sr_bit_offset + res->sr_bits) > (bitoff + bitcount))
1652		res->sr_bits = (bitoff + bitcount) - res->sr_bit_offset;
1653	return 1;
1654}
1655
1656static void ocfs2_bg_discontig_fix_result(struct ocfs2_alloc_context *ac,
1657					  struct ocfs2_group_desc *bg,
1658					  struct ocfs2_suballoc_result *res)
1659{
1660	int i;
1661	u64 bg_blkno = res->sr_bg_blkno;  /* Save off */
1662	struct ocfs2_extent_rec *rec;
1663	struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1664	struct ocfs2_chain_list *cl = &di->id2.i_chain;
1665
1666	if (ocfs2_is_cluster_bitmap(ac->ac_inode)) {
1667		res->sr_blkno = 0;
1668		return;
1669	}
1670
1671	res->sr_blkno = res->sr_bg_blkno + res->sr_bit_offset;
1672	res->sr_bg_blkno = 0;  /* Clear it for contig block groups */
1673	if (!ocfs2_supports_discontig_bg(OCFS2_SB(ac->ac_inode->i_sb)) ||
1674	    !bg->bg_list.l_next_free_rec)
1675		return;
1676
1677	for (i = 0; i < le16_to_cpu(bg->bg_list.l_next_free_rec); i++) {
1678		rec = &bg->bg_list.l_recs[i];
1679		if (ocfs2_bg_discontig_fix_by_rec(res, rec, cl)) {
1680			res->sr_bg_blkno = bg_blkno;  /* Restore */
1681			break;
1682		}
1683	}
1684}
1685
1686static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
1687				  handle_t *handle,
1688				  u32 bits_wanted,
1689				  u32 min_bits,
1690				  struct ocfs2_suballoc_result *res,
1691				  u16 *bits_left)
1692{
1693	int ret;
1694	struct buffer_head *group_bh = NULL;
1695	struct ocfs2_group_desc *gd;
1696	struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1697	struct inode *alloc_inode = ac->ac_inode;
1698
1699	ret = ocfs2_read_group_descriptor(alloc_inode, di,
1700					  res->sr_bg_blkno, &group_bh);
1701	if (ret < 0) {
1702		mlog_errno(ret);
1703		return ret;
1704	}
1705
1706	gd = (struct ocfs2_group_desc *) group_bh->b_data;
1707	ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
1708				  ac->ac_max_block, res);
1709	if (ret < 0) {
1710		if (ret != -ENOSPC)
1711			mlog_errno(ret);
1712		goto out;
1713	}
1714
1715	if (!ret)
1716		ocfs2_bg_discontig_fix_result(ac, gd, res);
1717
1718	/*
1719	 * sr_bg_blkno might have been changed by
1720	 * ocfs2_bg_discontig_fix_result
1721	 */
1722	res->sr_bg_stable_blkno = group_bh->b_blocknr;
1723
1724	if (ac->ac_find_loc_only)
1725		goto out_loc_only;
1726
1727	ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
1728					       res->sr_bits,
1729					       le16_to_cpu(gd->bg_chain));
1730	if (ret < 0) {
1731		mlog_errno(ret);
1732		goto out;
1733	}
1734
1735	ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
1736					 res->sr_bit_offset, res->sr_bits);
1737	if (ret < 0) {
1738		ocfs2_rollback_alloc_dinode_counts(alloc_inode, ac->ac_bh,
1739					       res->sr_bits,
1740					       le16_to_cpu(gd->bg_chain));
1741		mlog_errno(ret);
1742	}
1743
1744out_loc_only:
1745	*bits_left = le16_to_cpu(gd->bg_free_bits_count);
1746
1747out:
1748	brelse(group_bh);
1749
1750	return ret;
1751}
1752
1753static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
1754			      handle_t *handle,
1755			      u32 bits_wanted,
1756			      u32 min_bits,
1757			      struct ocfs2_suballoc_result *res,
1758			      u16 *bits_left)
1759{
1760	int status;
1761	u16 chain;
1762	u64 next_group;
1763	struct inode *alloc_inode = ac->ac_inode;
1764	struct buffer_head *group_bh = NULL;
1765	struct buffer_head *prev_group_bh = NULL;
1766	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1767	struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1768	struct ocfs2_group_desc *bg;
1769
1770	chain = ac->ac_chain;
1771	trace_ocfs2_search_chain_begin(
1772		(unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
1773		bits_wanted, chain);
1774
1775	status = ocfs2_read_group_descriptor(alloc_inode, fe,
1776					     le64_to_cpu(cl->cl_recs[chain].c_blkno),
1777					     &group_bh);
1778	if (status < 0) {
1779		mlog_errno(status);
1780		goto bail;
1781	}
1782	bg = (struct ocfs2_group_desc *) group_bh->b_data;
1783
1784	status = -ENOSPC;
1785	/* for now, the chain search is a bit simplistic. We just use
1786	 * the 1st group with any empty bits. */
1787	while ((status = ac->ac_group_search(alloc_inode, group_bh,
1788					     bits_wanted, min_bits,
1789					     ac->ac_max_block,
1790					     res)) == -ENOSPC) {
1791		if (!bg->bg_next_group)
1792			break;
1793
1794		brelse(prev_group_bh);
1795		prev_group_bh = NULL;
1796
1797		next_group = le64_to_cpu(bg->bg_next_group);
1798		prev_group_bh = group_bh;
1799		group_bh = NULL;
1800		status = ocfs2_read_group_descriptor(alloc_inode, fe,
1801						     next_group, &group_bh);
1802		if (status < 0) {
1803			mlog_errno(status);
1804			goto bail;
1805		}
1806		bg = (struct ocfs2_group_desc *) group_bh->b_data;
1807	}
1808	if (status < 0) {
1809		if (status != -ENOSPC)
1810			mlog_errno(status);
1811		goto bail;
1812	}
1813
1814	trace_ocfs2_search_chain_succ(
1815		(unsigned long long)le64_to_cpu(bg->bg_blkno), res->sr_bits);
1816
1817	res->sr_bg_blkno = le64_to_cpu(bg->bg_blkno);
1818
1819	BUG_ON(res->sr_bits == 0);
1820	if (!status)
1821		ocfs2_bg_discontig_fix_result(ac, bg, res);
1822
1823	/*
1824	 * sr_bg_blkno might have been changed by
1825	 * ocfs2_bg_discontig_fix_result
1826	 */
1827	res->sr_bg_stable_blkno = group_bh->b_blocknr;
1828
1829	/*
1830	 * Keep track of previous block descriptor read. When
1831	 * we find a target, if we have read more than X
1832	 * number of descriptors, and the target is reasonably
1833	 * empty, relink him to top of his chain.
1834	 *
1835	 * We've read 0 extra blocks and only send one more to
1836	 * the transaction, yet the next guy to search has a
1837	 * much easier time.
1838	 *
1839	 * Do this *after* figuring out how many bits we're taking out
1840	 * of our target group.
1841	 */
1842	if (!ac->ac_disable_chain_relink &&
1843	    (prev_group_bh) &&
1844	    (ocfs2_block_group_reasonably_empty(bg, res->sr_bits))) {
1845		status = ocfs2_relink_block_group(handle, alloc_inode,
1846						  ac->ac_bh, group_bh,
1847						  prev_group_bh, chain);
1848		if (status < 0) {
1849			mlog_errno(status);
1850			goto bail;
1851		}
1852	}
1853
1854	if (ac->ac_find_loc_only)
1855		goto out_loc_only;
1856
1857	status = ocfs2_alloc_dinode_update_counts(alloc_inode, handle,
1858						  ac->ac_bh, res->sr_bits,
1859						  chain);
1860	if (status) {
1861		mlog_errno(status);
1862		goto bail;
1863	}
1864
1865	status = ocfs2_block_group_set_bits(handle,
1866					    alloc_inode,
1867					    bg,
1868					    group_bh,
1869					    res->sr_bit_offset,
1870					    res->sr_bits);
1871	if (status < 0) {
1872		ocfs2_rollback_alloc_dinode_counts(alloc_inode,
1873					ac->ac_bh, res->sr_bits, chain);
1874		mlog_errno(status);
1875		goto bail;
1876	}
1877
1878	trace_ocfs2_search_chain_end(
1879			(unsigned long long)le64_to_cpu(fe->i_blkno),
1880			res->sr_bits);
1881
1882out_loc_only:
1883	*bits_left = le16_to_cpu(bg->bg_free_bits_count);
1884bail:
1885	brelse(group_bh);
1886	brelse(prev_group_bh);
1887
1888	if (status)
1889		mlog_errno(status);
1890	return status;
1891}
1892
1893/* will give out up to bits_wanted contiguous bits. */
1894static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
1895				     handle_t *handle,
1896				     u32 bits_wanted,
1897				     u32 min_bits,
1898				     struct ocfs2_suballoc_result *res)
1899{
1900	int status;
1901	u16 victim, i;
1902	u16 bits_left = 0;
1903	u64 hint = ac->ac_last_group;
1904	struct ocfs2_chain_list *cl;
1905	struct ocfs2_dinode *fe;
1906
1907	BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1908	BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1909	BUG_ON(!ac->ac_bh);
1910
1911	fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1912
1913	/* The bh was validated by the inode read during
1914	 * ocfs2_reserve_suballoc_bits().  Any corruption is a code bug. */
1915	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
1916
1917	if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1918	    le32_to_cpu(fe->id1.bitmap1.i_total)) {
1919		status = ocfs2_error(ac->ac_inode->i_sb,
1920				     "Chain allocator dinode %llu has %u used bits but only %u total\n",
1921				     (unsigned long long)le64_to_cpu(fe->i_blkno),
1922				     le32_to_cpu(fe->id1.bitmap1.i_used),
1923				     le32_to_cpu(fe->id1.bitmap1.i_total));
1924		goto bail;
1925	}
1926
1927	res->sr_bg_blkno = hint;
1928	if (res->sr_bg_blkno) {
1929		/* Attempt to short-circuit the usual search mechanism
1930		 * by jumping straight to the most recently used
1931		 * allocation group. This helps us maintain some
1932		 * contiguousness across allocations. */
1933		status = ocfs2_search_one_group(ac, handle, bits_wanted,
1934						min_bits, res, &bits_left);
1935		if (!status)
1936			goto set_hint;
1937		if (status < 0 && status != -ENOSPC) {
1938			mlog_errno(status);
1939			goto bail;
1940		}
1941	}
1942
1943	cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1944
1945	victim = ocfs2_find_victim_chain(cl);
1946	ac->ac_chain = victim;
1947
1948	status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1949				    res, &bits_left);
1950	if (!status) {
1951		if (ocfs2_is_cluster_bitmap(ac->ac_inode))
1952			hint = res->sr_bg_blkno;
1953		else
1954			hint = ocfs2_group_from_res(res);
1955		goto set_hint;
1956	}
1957	if (status < 0 && status != -ENOSPC) {
1958		mlog_errno(status);
1959		goto bail;
1960	}
1961
1962	trace_ocfs2_claim_suballoc_bits(victim);
1963
1964	/* If we didn't pick a good victim, then just default to
1965	 * searching each chain in order. Don't allow chain relinking
1966	 * because we only calculate enough journal credits for one
1967	 * relink per alloc. */
1968	ac->ac_disable_chain_relink = 1;
1969	for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
1970		if (i == victim)
1971			continue;
1972		if (!cl->cl_recs[i].c_free)
1973			continue;
1974
1975		ac->ac_chain = i;
1976		status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1977					    res, &bits_left);
1978		if (!status) {
1979			hint = ocfs2_group_from_res(res);
1980			break;
1981		}
1982		if (status < 0 && status != -ENOSPC) {
1983			mlog_errno(status);
1984			goto bail;
1985		}
1986	}
1987
1988set_hint:
1989	if (status != -ENOSPC) {
1990		/* If the next search of this group is not likely to
1991		 * yield a suitable extent, then we reset the last
1992		 * group hint so as to not waste a disk read */
1993		if (bits_left < min_bits)
1994			ac->ac_last_group = 0;
1995		else
1996			ac->ac_last_group = hint;
1997	}
1998
1999bail:
2000	if (status)
2001		mlog_errno(status);
2002	return status;
2003}
2004
2005int ocfs2_claim_metadata(handle_t *handle,
2006			 struct ocfs2_alloc_context *ac,
2007			 u32 bits_wanted,
2008			 u64 *suballoc_loc,
2009			 u16 *suballoc_bit_start,
2010			 unsigned int *num_bits,
2011			 u64 *blkno_start)
2012{
2013	int status;
2014	struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
2015
2016	BUG_ON(!ac);
2017	BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
2018	BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
2019
2020	status = ocfs2_claim_suballoc_bits(ac,
2021					   handle,
2022					   bits_wanted,
2023					   1,
2024					   &res);
2025	if (status < 0) {
2026		mlog_errno(status);
2027		goto bail;
2028	}
2029	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2030
2031	*suballoc_loc = res.sr_bg_blkno;
2032	*suballoc_bit_start = res.sr_bit_offset;
2033	*blkno_start = res.sr_blkno;
2034	ac->ac_bits_given += res.sr_bits;
2035	*num_bits = res.sr_bits;
2036	status = 0;
2037bail:
2038	if (status)
2039		mlog_errno(status);
2040	return status;
2041}
2042
2043static void ocfs2_init_inode_ac_group(struct inode *dir,
2044				      struct buffer_head *parent_di_bh,
2045				      struct ocfs2_alloc_context *ac)
2046{
2047	struct ocfs2_dinode *di = (struct ocfs2_dinode *)parent_di_bh->b_data;
2048	/*
2049	 * Try to allocate inodes from some specific group.
2050	 *
2051	 * If the parent dir has recorded the last group used in allocation,
2052	 * cool, use it. Otherwise if we try to allocate new inode from the
2053	 * same slot the parent dir belongs to, use the same chunk.
2054	 *
2055	 * We are very careful here to avoid the mistake of setting
2056	 * ac_last_group to a group descriptor from a different (unlocked) slot.
2057	 */
2058	if (OCFS2_I(dir)->ip_last_used_group &&
2059	    OCFS2_I(dir)->ip_last_used_slot == ac->ac_alloc_slot)
2060		ac->ac_last_group = OCFS2_I(dir)->ip_last_used_group;
2061	else if (le16_to_cpu(di->i_suballoc_slot) == ac->ac_alloc_slot) {
2062		if (di->i_suballoc_loc)
2063			ac->ac_last_group = le64_to_cpu(di->i_suballoc_loc);
2064		else
2065			ac->ac_last_group = ocfs2_which_suballoc_group(
2066					le64_to_cpu(di->i_blkno),
2067					le16_to_cpu(di->i_suballoc_bit));
2068	}
2069}
2070
2071static inline void ocfs2_save_inode_ac_group(struct inode *dir,
2072					     struct ocfs2_alloc_context *ac)
2073{
2074	OCFS2_I(dir)->ip_last_used_group = ac->ac_last_group;
2075	OCFS2_I(dir)->ip_last_used_slot = ac->ac_alloc_slot;
2076}
2077
2078int ocfs2_find_new_inode_loc(struct inode *dir,
2079			     struct buffer_head *parent_fe_bh,
2080			     struct ocfs2_alloc_context *ac,
2081			     u64 *fe_blkno)
2082{
2083	int ret;
2084	handle_t *handle = NULL;
2085	struct ocfs2_suballoc_result *res;
2086
2087	BUG_ON(!ac);
2088	BUG_ON(ac->ac_bits_given != 0);
2089	BUG_ON(ac->ac_bits_wanted != 1);
2090	BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2091
2092	res = kzalloc(sizeof(*res), GFP_NOFS);
2093	if (res == NULL) {
2094		ret = -ENOMEM;
2095		mlog_errno(ret);
2096		goto out;
2097	}
2098
2099	ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2100
2101	/*
2102	 * The handle started here is for chain relink. Alternatively,
2103	 * we could just disable relink for these calls.
2104	 */
2105	handle = ocfs2_start_trans(OCFS2_SB(dir->i_sb), OCFS2_SUBALLOC_ALLOC);
2106	if (IS_ERR(handle)) {
2107		ret = PTR_ERR(handle);
2108		handle = NULL;
2109		mlog_errno(ret);
2110		goto out;
2111	}
2112
2113	/*
2114	 * This will instruct ocfs2_claim_suballoc_bits and
2115	 * ocfs2_search_one_group to search but save actual allocation
2116	 * for later.
2117	 */
2118	ac->ac_find_loc_only = 1;
2119
2120	ret = ocfs2_claim_suballoc_bits(ac, handle, 1, 1, res);
2121	if (ret < 0) {
2122		mlog_errno(ret);
2123		goto out;
2124	}
2125
2126	ac->ac_find_loc_priv = res;
2127	*fe_blkno = res->sr_blkno;
2128	ocfs2_update_inode_fsync_trans(handle, dir, 0);
2129out:
2130	if (handle)
2131		ocfs2_commit_trans(OCFS2_SB(dir->i_sb), handle);
2132
2133	if (ret)
2134		kfree(res);
2135
2136	return ret;
2137}
2138
2139int ocfs2_claim_new_inode_at_loc(handle_t *handle,
2140				 struct inode *dir,
2141				 struct ocfs2_alloc_context *ac,
2142				 u64 *suballoc_loc,
2143				 u16 *suballoc_bit,
2144				 u64 di_blkno)
2145{
2146	int ret;
2147	u16 chain;
2148	struct ocfs2_suballoc_result *res = ac->ac_find_loc_priv;
2149	struct buffer_head *bg_bh = NULL;
2150	struct ocfs2_group_desc *bg;
2151	struct ocfs2_dinode *di = (struct ocfs2_dinode *) ac->ac_bh->b_data;
2152
2153	/*
2154	 * Since di_blkno is being passed back in, we check for any
2155	 * inconsistencies which may have happened between
2156	 * calls. These are code bugs as di_blkno is not expected to
2157	 * change once returned from ocfs2_find_new_inode_loc()
2158	 */
2159	BUG_ON(res->sr_blkno != di_blkno);
2160
2161	ret = ocfs2_read_group_descriptor(ac->ac_inode, di,
2162					  res->sr_bg_stable_blkno, &bg_bh);
2163	if (ret) {
2164		mlog_errno(ret);
2165		goto out;
2166	}
2167
2168	bg = (struct ocfs2_group_desc *) bg_bh->b_data;
2169	chain = le16_to_cpu(bg->bg_chain);
2170
2171	ret = ocfs2_alloc_dinode_update_counts(ac->ac_inode, handle,
2172					       ac->ac_bh, res->sr_bits,
2173					       chain);
2174	if (ret) {
2175		mlog_errno(ret);
2176		goto out;
2177	}
2178
2179	ret = ocfs2_block_group_set_bits(handle,
2180					 ac->ac_inode,
2181					 bg,
2182					 bg_bh,
2183					 res->sr_bit_offset,
2184					 res->sr_bits);
2185	if (ret < 0) {
2186		ocfs2_rollback_alloc_dinode_counts(ac->ac_inode,
2187					       ac->ac_bh, res->sr_bits, chain);
2188		mlog_errno(ret);
2189		goto out;
2190	}
2191
2192	trace_ocfs2_claim_new_inode_at_loc((unsigned long long)di_blkno,
2193					   res->sr_bits);
2194
2195	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2196
2197	BUG_ON(res->sr_bits != 1);
2198
2199	*suballoc_loc = res->sr_bg_blkno;
2200	*suballoc_bit = res->sr_bit_offset;
2201	ac->ac_bits_given++;
2202	ocfs2_save_inode_ac_group(dir, ac);
2203
2204out:
2205	brelse(bg_bh);
2206
2207	return ret;
2208}
2209
2210int ocfs2_claim_new_inode(handle_t *handle,
2211			  struct inode *dir,
2212			  struct buffer_head *parent_fe_bh,
2213			  struct ocfs2_alloc_context *ac,
2214			  u64 *suballoc_loc,
2215			  u16 *suballoc_bit,
2216			  u64 *fe_blkno)
2217{
2218	int status;
2219	struct ocfs2_suballoc_result res;
2220
2221	BUG_ON(!ac);
2222	BUG_ON(ac->ac_bits_given != 0);
2223	BUG_ON(ac->ac_bits_wanted != 1);
2224	BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2225
2226	ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2227
2228	status = ocfs2_claim_suballoc_bits(ac,
2229					   handle,
2230					   1,
2231					   1,
2232					   &res);
2233	if (status < 0) {
2234		mlog_errno(status);
2235		goto bail;
2236	}
2237	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2238
2239	BUG_ON(res.sr_bits != 1);
2240
2241	*suballoc_loc = res.sr_bg_blkno;
2242	*suballoc_bit = res.sr_bit_offset;
2243	*fe_blkno = res.sr_blkno;
2244	ac->ac_bits_given++;
2245	ocfs2_save_inode_ac_group(dir, ac);
2246	status = 0;
2247bail:
2248	if (status)
2249		mlog_errno(status);
2250	return status;
2251}
2252
2253/* translate a group desc. blkno and it's bitmap offset into
2254 * disk cluster offset. */
2255static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
2256						   u64 bg_blkno,
2257						   u16 bg_bit_off)
2258{
2259	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2260	u32 cluster = 0;
2261
2262	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2263
2264	if (bg_blkno != osb->first_cluster_group_blkno)
2265		cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
2266	cluster += (u32) bg_bit_off;
2267	return cluster;
2268}
2269
2270/* given a cluster offset, calculate which block group it belongs to
2271 * and return that block offset. */
2272u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster)
2273{
2274	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2275	u32 group_no;
2276
2277	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2278
2279	group_no = cluster / osb->bitmap_cpg;
2280	if (!group_no)
2281		return osb->first_cluster_group_blkno;
2282	return ocfs2_clusters_to_blocks(inode->i_sb,
2283					group_no * osb->bitmap_cpg);
2284}
2285
2286/* given the block number of a cluster start, calculate which cluster
2287 * group and descriptor bitmap offset that corresponds to. */
2288static inline void ocfs2_block_to_cluster_group(struct inode *inode,
2289						u64 data_blkno,
2290						u64 *bg_blkno,
2291						u16 *bg_bit_off)
2292{
2293	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2294	u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
2295
2296	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2297
2298	*bg_blkno = ocfs2_which_cluster_group(inode,
2299					      data_cluster);
2300
2301	if (*bg_blkno == osb->first_cluster_group_blkno)
2302		*bg_bit_off = (u16) data_cluster;
2303	else
2304		*bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
2305							     data_blkno - *bg_blkno);
2306}
2307
2308/*
2309 * min_bits - minimum contiguous chunk from this total allocation we
2310 * can handle. set to what we asked for originally for a full
2311 * contig. allocation, set to '1' to indicate we can deal with extents
2312 * of any size.
2313 */
2314int __ocfs2_claim_clusters(handle_t *handle,
2315			   struct ocfs2_alloc_context *ac,
2316			   u32 min_clusters,
2317			   u32 max_clusters,
2318			   u32 *cluster_start,
2319			   u32 *num_clusters)
2320{
2321	int status;
2322	unsigned int bits_wanted = max_clusters;
2323	struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
2324	struct ocfs2_super *osb = OCFS2_SB(ac->ac_inode->i_sb);
2325
2326	BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
2327
2328	BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
2329	       && ac->ac_which != OCFS2_AC_USE_MAIN);
2330
2331	if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
2332		WARN_ON(min_clusters > 1);
2333
2334		status = ocfs2_claim_local_alloc_bits(osb,
2335						      handle,
2336						      ac,
2337						      bits_wanted,
2338						      cluster_start,
2339						      num_clusters);
2340		if (!status)
2341			atomic_inc(&osb->alloc_stats.local_data);
2342	} else {
2343		if (min_clusters > (osb->bitmap_cpg - 1)) {
2344			/* The only paths asking for contiguousness
2345			 * should know about this already. */
2346			mlog(ML_ERROR, "minimum allocation requested %u exceeds "
2347			     "group bitmap size %u!\n", min_clusters,
2348			     osb->bitmap_cpg);
2349			status = -ENOSPC;
2350			goto bail;
2351		}
2352		/* clamp the current request down to a realistic size. */
2353		if (bits_wanted > (osb->bitmap_cpg - 1))
2354			bits_wanted = osb->bitmap_cpg - 1;
2355
2356		status = ocfs2_claim_suballoc_bits(ac,
2357						   handle,
2358						   bits_wanted,
2359						   min_clusters,
2360						   &res);
2361		if (!status) {
2362			BUG_ON(res.sr_blkno); /* cluster alloc can't set */
2363			*cluster_start =
2364				ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
2365								 res.sr_bg_blkno,
2366								 res.sr_bit_offset);
2367			atomic_inc(&osb->alloc_stats.bitmap_data);
2368			*num_clusters = res.sr_bits;
2369		}
2370	}
2371	if (status < 0) {
2372		if (status != -ENOSPC)
2373			mlog_errno(status);
2374		goto bail;
2375	}
2376
2377	ac->ac_bits_given += *num_clusters;
2378
2379bail:
2380	if (status)
2381		mlog_errno(status);
2382	return status;
2383}
2384
2385int ocfs2_claim_clusters(handle_t *handle,
2386			 struct ocfs2_alloc_context *ac,
2387			 u32 min_clusters,
2388			 u32 *cluster_start,
2389			 u32 *num_clusters)
2390{
2391	unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
2392
2393	return __ocfs2_claim_clusters(handle, ac, min_clusters,
2394				      bits_wanted, cluster_start, num_clusters);
2395}
2396
2397static int ocfs2_block_group_clear_bits(handle_t *handle,
2398					struct inode *alloc_inode,
2399					struct ocfs2_group_desc *bg,
2400					struct buffer_head *group_bh,
2401					unsigned int bit_off,
2402					unsigned int num_bits,
2403					void (*undo_fn)(unsigned int bit,
2404							unsigned long *bmap))
2405{
2406	int status;
2407	unsigned int tmp;
2408	struct ocfs2_group_desc *undo_bg = NULL;
 
2409
2410	/* The caller got this descriptor from
2411	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
2412	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
2413
2414	trace_ocfs2_block_group_clear_bits(bit_off, num_bits);
2415
2416	BUG_ON(undo_fn && !ocfs2_is_cluster_bitmap(alloc_inode));
2417	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
2418					 group_bh,
2419					 undo_fn ?
2420					 OCFS2_JOURNAL_ACCESS_UNDO :
2421					 OCFS2_JOURNAL_ACCESS_WRITE);
2422	if (status < 0) {
2423		mlog_errno(status);
2424		goto bail;
2425	}
2426
 
2427	if (undo_fn) {
2428		jbd_lock_bh_state(group_bh);
2429		undo_bg = (struct ocfs2_group_desc *)
2430					bh2jh(group_bh)->b_committed_data;
2431		BUG_ON(!undo_bg);
2432	}
2433
2434	tmp = num_bits;
2435	while(tmp--) {
2436		ocfs2_clear_bit((bit_off + tmp),
2437				(unsigned long *) bg->bg_bitmap);
2438		if (undo_fn)
2439			undo_fn(bit_off + tmp,
2440				(unsigned long *) undo_bg->bg_bitmap);
2441	}
2442	le16_add_cpu(&bg->bg_free_bits_count, num_bits);
2443	if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
 
 
2444		return ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit count %u but claims %u are freed. num_bits %d\n",
2445				   (unsigned long long)le64_to_cpu(bg->bg_blkno),
2446				   le16_to_cpu(bg->bg_bits),
2447				   le16_to_cpu(bg->bg_free_bits_count),
2448				   num_bits);
2449	}
2450
2451	if (undo_fn)
2452		jbd_unlock_bh_state(group_bh);
2453
2454	ocfs2_journal_dirty(handle, group_bh);
2455bail:
2456	return status;
2457}
2458
2459/*
2460 * expects the suballoc inode to already be locked.
2461 */
2462static int _ocfs2_free_suballoc_bits(handle_t *handle,
2463				     struct inode *alloc_inode,
2464				     struct buffer_head *alloc_bh,
2465				     unsigned int start_bit,
2466				     u64 bg_blkno,
2467				     unsigned int count,
2468				     void (*undo_fn)(unsigned int bit,
2469						     unsigned long *bitmap))
2470{
2471	int status = 0;
2472	u32 tmp_used;
2473	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
2474	struct ocfs2_chain_list *cl = &fe->id2.i_chain;
2475	struct buffer_head *group_bh = NULL;
2476	struct ocfs2_group_desc *group;
2477
2478	/* The alloc_bh comes from ocfs2_free_dinode() or
2479	 * ocfs2_free_clusters().  The callers have all locked the
2480	 * allocator and gotten alloc_bh from the lock call.  This
2481	 * validates the dinode buffer.  Any corruption that has happened
2482	 * is a code bug. */
2483	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
2484	BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
2485
2486	trace_ocfs2_free_suballoc_bits(
2487		(unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
2488		(unsigned long long)bg_blkno,
2489		start_bit, count);
2490
2491	status = ocfs2_read_group_descriptor(alloc_inode, fe, bg_blkno,
2492					     &group_bh);
2493	if (status < 0) {
2494		mlog_errno(status);
2495		goto bail;
2496	}
2497	group = (struct ocfs2_group_desc *) group_bh->b_data;
2498
2499	BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
2500
2501	status = ocfs2_block_group_clear_bits(handle, alloc_inode,
2502					      group, group_bh,
2503					      start_bit, count, undo_fn);
2504	if (status < 0) {
2505		mlog_errno(status);
2506		goto bail;
2507	}
2508
2509	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
2510					 alloc_bh, OCFS2_JOURNAL_ACCESS_WRITE);
2511	if (status < 0) {
2512		mlog_errno(status);
2513		ocfs2_block_group_set_bits(handle, alloc_inode, group, group_bh,
2514				start_bit, count);
2515		goto bail;
2516	}
2517
2518	le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
2519		     count);
2520	tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
2521	fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
2522	ocfs2_journal_dirty(handle, alloc_bh);
2523
2524bail:
2525	brelse(group_bh);
2526
2527	if (status)
2528		mlog_errno(status);
2529	return status;
2530}
2531
2532int ocfs2_free_suballoc_bits(handle_t *handle,
2533			     struct inode *alloc_inode,
2534			     struct buffer_head *alloc_bh,
2535			     unsigned int start_bit,
2536			     u64 bg_blkno,
2537			     unsigned int count)
2538{
2539	return _ocfs2_free_suballoc_bits(handle, alloc_inode, alloc_bh,
2540					 start_bit, bg_blkno, count, NULL);
2541}
2542
2543int ocfs2_free_dinode(handle_t *handle,
2544		      struct inode *inode_alloc_inode,
2545		      struct buffer_head *inode_alloc_bh,
2546		      struct ocfs2_dinode *di)
2547{
2548	u64 blk = le64_to_cpu(di->i_blkno);
2549	u16 bit = le16_to_cpu(di->i_suballoc_bit);
2550	u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
2551
2552	if (di->i_suballoc_loc)
2553		bg_blkno = le64_to_cpu(di->i_suballoc_loc);
2554	return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
2555					inode_alloc_bh, bit, bg_blkno, 1);
2556}
2557
2558static int _ocfs2_free_clusters(handle_t *handle,
2559				struct inode *bitmap_inode,
2560				struct buffer_head *bitmap_bh,
2561				u64 start_blk,
2562				unsigned int num_clusters,
2563				void (*undo_fn)(unsigned int bit,
2564						unsigned long *bitmap))
2565{
2566	int status;
2567	u16 bg_start_bit;
2568	u64 bg_blkno;
2569	struct ocfs2_dinode *fe;
2570
2571	/* You can't ever have a contiguous set of clusters
2572	 * bigger than a block group bitmap so we never have to worry
2573	 * about looping on them.
2574	 * This is expensive. We can safely remove once this stuff has
2575	 * gotten tested really well. */
2576	BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb, ocfs2_blocks_to_clusters(bitmap_inode->i_sb, start_blk)));
 
 
2577
2578	fe = (struct ocfs2_dinode *) bitmap_bh->b_data;
2579
2580	ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
2581				     &bg_start_bit);
2582
2583	trace_ocfs2_free_clusters((unsigned long long)bg_blkno,
2584			(unsigned long long)start_blk,
2585			bg_start_bit, num_clusters);
2586
2587	status = _ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
2588					   bg_start_bit, bg_blkno,
2589					   num_clusters, undo_fn);
2590	if (status < 0) {
2591		mlog_errno(status);
2592		goto out;
2593	}
2594
2595	ocfs2_local_alloc_seen_free_bits(OCFS2_SB(bitmap_inode->i_sb),
2596					 num_clusters);
2597
2598out:
2599	if (status)
2600		mlog_errno(status);
2601	return status;
2602}
2603
2604int ocfs2_free_clusters(handle_t *handle,
2605			struct inode *bitmap_inode,
2606			struct buffer_head *bitmap_bh,
2607			u64 start_blk,
2608			unsigned int num_clusters)
2609{
2610	return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2611				    start_blk, num_clusters,
2612				    _ocfs2_set_bit);
2613}
2614
2615/*
2616 * Give never-used clusters back to the global bitmap.  We don't need
2617 * to protect these bits in the undo buffer.
2618 */
2619int ocfs2_release_clusters(handle_t *handle,
2620			   struct inode *bitmap_inode,
2621			   struct buffer_head *bitmap_bh,
2622			   u64 start_blk,
2623			   unsigned int num_clusters)
2624{
2625	return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2626				    start_blk, num_clusters,
2627				    _ocfs2_clear_bit);
2628}
2629
2630static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg)
2631{
2632	printk("Block Group:\n");
2633	printk("bg_signature:       %s\n", bg->bg_signature);
2634	printk("bg_size:            %u\n", bg->bg_size);
2635	printk("bg_bits:            %u\n", bg->bg_bits);
2636	printk("bg_free_bits_count: %u\n", bg->bg_free_bits_count);
2637	printk("bg_chain:           %u\n", bg->bg_chain);
2638	printk("bg_generation:      %u\n", le32_to_cpu(bg->bg_generation));
2639	printk("bg_next_group:      %llu\n",
2640	       (unsigned long long)bg->bg_next_group);
2641	printk("bg_parent_dinode:   %llu\n",
2642	       (unsigned long long)bg->bg_parent_dinode);
2643	printk("bg_blkno:           %llu\n",
2644	       (unsigned long long)bg->bg_blkno);
2645}
2646
2647static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe)
2648{
2649	int i;
2650
2651	printk("Suballoc Inode %llu:\n", (unsigned long long)fe->i_blkno);
2652	printk("i_signature:                  %s\n", fe->i_signature);
2653	printk("i_size:                       %llu\n",
2654	       (unsigned long long)fe->i_size);
2655	printk("i_clusters:                   %u\n", fe->i_clusters);
2656	printk("i_generation:                 %u\n",
2657	       le32_to_cpu(fe->i_generation));
2658	printk("id1.bitmap1.i_used:           %u\n",
2659	       le32_to_cpu(fe->id1.bitmap1.i_used));
2660	printk("id1.bitmap1.i_total:          %u\n",
2661	       le32_to_cpu(fe->id1.bitmap1.i_total));
2662	printk("id2.i_chain.cl_cpg:           %u\n", fe->id2.i_chain.cl_cpg);
2663	printk("id2.i_chain.cl_bpc:           %u\n", fe->id2.i_chain.cl_bpc);
2664	printk("id2.i_chain.cl_count:         %u\n", fe->id2.i_chain.cl_count);
2665	printk("id2.i_chain.cl_next_free_rec: %u\n",
2666	       fe->id2.i_chain.cl_next_free_rec);
2667	for(i = 0; i < fe->id2.i_chain.cl_next_free_rec; i++) {
2668		printk("fe->id2.i_chain.cl_recs[%d].c_free:  %u\n", i,
2669		       fe->id2.i_chain.cl_recs[i].c_free);
2670		printk("fe->id2.i_chain.cl_recs[%d].c_total: %u\n", i,
2671		       fe->id2.i_chain.cl_recs[i].c_total);
2672		printk("fe->id2.i_chain.cl_recs[%d].c_blkno: %llu\n", i,
2673		       (unsigned long long)fe->id2.i_chain.cl_recs[i].c_blkno);
2674	}
2675}
2676
2677/*
2678 * For a given allocation, determine which allocators will need to be
2679 * accessed, and lock them, reserving the appropriate number of bits.
2680 *
2681 * Sparse file systems call this from ocfs2_write_begin_nolock()
2682 * and ocfs2_allocate_unwritten_extents().
2683 *
2684 * File systems which don't support holes call this from
2685 * ocfs2_extend_allocation().
2686 */
2687int ocfs2_lock_allocators(struct inode *inode,
2688			  struct ocfs2_extent_tree *et,
2689			  u32 clusters_to_add, u32 extents_to_split,
2690			  struct ocfs2_alloc_context **data_ac,
2691			  struct ocfs2_alloc_context **meta_ac)
2692{
2693	int ret = 0, num_free_extents;
2694	unsigned int max_recs_needed = clusters_to_add + 2 * extents_to_split;
2695	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2696
2697	*meta_ac = NULL;
2698	if (data_ac)
2699		*data_ac = NULL;
2700
2701	BUG_ON(clusters_to_add != 0 && data_ac == NULL);
2702
2703	num_free_extents = ocfs2_num_free_extents(osb, et);
2704	if (num_free_extents < 0) {
2705		ret = num_free_extents;
2706		mlog_errno(ret);
2707		goto out;
2708	}
2709
2710	/*
2711	 * Sparse allocation file systems need to be more conservative
2712	 * with reserving room for expansion - the actual allocation
2713	 * happens while we've got a journal handle open so re-taking
2714	 * a cluster lock (because we ran out of room for another
2715	 * extent) will violate ordering rules.
2716	 *
2717	 * Most of the time we'll only be seeing this 1 cluster at a time
2718	 * anyway.
2719	 *
2720	 * Always lock for any unwritten extents - we might want to
2721	 * add blocks during a split.
2722	 */
2723	if (!num_free_extents ||
2724	    (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed)) {
2725		ret = ocfs2_reserve_new_metadata(osb, et->et_root_el, meta_ac);
2726		if (ret < 0) {
2727			if (ret != -ENOSPC)
2728				mlog_errno(ret);
2729			goto out;
2730		}
2731	}
2732
2733	if (clusters_to_add == 0)
2734		goto out;
2735
2736	ret = ocfs2_reserve_clusters(osb, clusters_to_add, data_ac);
2737	if (ret < 0) {
2738		if (ret != -ENOSPC)
2739			mlog_errno(ret);
2740		goto out;
2741	}
2742
2743out:
2744	if (ret) {
2745		if (*meta_ac) {
2746			ocfs2_free_alloc_context(*meta_ac);
2747			*meta_ac = NULL;
2748		}
2749
2750		/*
2751		 * We cannot have an error and a non null *data_ac.
2752		 */
2753	}
2754
2755	return ret;
2756}
2757
2758/*
2759 * Read the inode specified by blkno to get suballoc_slot and
2760 * suballoc_bit.
2761 */
2762static int ocfs2_get_suballoc_slot_bit(struct ocfs2_super *osb, u64 blkno,
2763				       u16 *suballoc_slot, u64 *group_blkno,
2764				       u16 *suballoc_bit)
2765{
2766	int status;
2767	struct buffer_head *inode_bh = NULL;
2768	struct ocfs2_dinode *inode_fe;
2769
2770	trace_ocfs2_get_suballoc_slot_bit((unsigned long long)blkno);
2771
2772	/* dirty read disk */
2773	status = ocfs2_read_blocks_sync(osb, blkno, 1, &inode_bh);
2774	if (status < 0) {
2775		mlog(ML_ERROR, "read block %llu failed %d\n",
2776		     (unsigned long long)blkno, status);
2777		goto bail;
2778	}
2779
2780	inode_fe = (struct ocfs2_dinode *) inode_bh->b_data;
2781	if (!OCFS2_IS_VALID_DINODE(inode_fe)) {
2782		mlog(ML_ERROR, "invalid inode %llu requested\n",
2783		     (unsigned long long)blkno);
2784		status = -EINVAL;
2785		goto bail;
2786	}
2787
2788	if (le16_to_cpu(inode_fe->i_suballoc_slot) != (u16)OCFS2_INVALID_SLOT &&
2789	    (u32)le16_to_cpu(inode_fe->i_suballoc_slot) > osb->max_slots - 1) {
2790		mlog(ML_ERROR, "inode %llu has invalid suballoc slot %u\n",
2791		     (unsigned long long)blkno,
2792		     (u32)le16_to_cpu(inode_fe->i_suballoc_slot));
2793		status = -EINVAL;
2794		goto bail;
2795	}
2796
2797	if (suballoc_slot)
2798		*suballoc_slot = le16_to_cpu(inode_fe->i_suballoc_slot);
2799	if (suballoc_bit)
2800		*suballoc_bit = le16_to_cpu(inode_fe->i_suballoc_bit);
2801	if (group_blkno)
2802		*group_blkno = le64_to_cpu(inode_fe->i_suballoc_loc);
2803
2804bail:
2805	brelse(inode_bh);
2806
2807	if (status)
2808		mlog_errno(status);
2809	return status;
2810}
2811
2812/*
2813 * test whether bit is SET in allocator bitmap or not.  on success, 0
2814 * is returned and *res is 1 for SET; 0 otherwise.  when fails, errno
2815 * is returned and *res is meaningless.  Call this after you have
2816 * cluster locked against suballoc, or you may get a result based on
2817 * non-up2date contents
2818 */
2819static int ocfs2_test_suballoc_bit(struct ocfs2_super *osb,
2820				   struct inode *suballoc,
2821				   struct buffer_head *alloc_bh,
2822				   u64 group_blkno, u64 blkno,
2823				   u16 bit, int *res)
2824{
2825	struct ocfs2_dinode *alloc_di;
2826	struct ocfs2_group_desc *group;
2827	struct buffer_head *group_bh = NULL;
2828	u64 bg_blkno;
2829	int status;
2830
2831	trace_ocfs2_test_suballoc_bit((unsigned long long)blkno,
2832				      (unsigned int)bit);
2833
2834	alloc_di = (struct ocfs2_dinode *)alloc_bh->b_data;
2835	if ((bit + 1) > ocfs2_bits_per_group(&alloc_di->id2.i_chain)) {
2836		mlog(ML_ERROR, "suballoc bit %u out of range of %u\n",
2837		     (unsigned int)bit,
2838		     ocfs2_bits_per_group(&alloc_di->id2.i_chain));
2839		status = -EINVAL;
2840		goto bail;
2841	}
2842
2843	bg_blkno = group_blkno ? group_blkno :
2844		   ocfs2_which_suballoc_group(blkno, bit);
2845	status = ocfs2_read_group_descriptor(suballoc, alloc_di, bg_blkno,
2846					     &group_bh);
2847	if (status < 0) {
2848		mlog(ML_ERROR, "read group %llu failed %d\n",
2849		     (unsigned long long)bg_blkno, status);
2850		goto bail;
2851	}
2852
2853	group = (struct ocfs2_group_desc *) group_bh->b_data;
2854	*res = ocfs2_test_bit(bit, (unsigned long *)group->bg_bitmap);
2855
2856bail:
2857	brelse(group_bh);
2858
2859	if (status)
2860		mlog_errno(status);
2861	return status;
2862}
2863
2864/*
2865 * Test if the bit representing this inode (blkno) is set in the
2866 * suballocator.
2867 *
2868 * On success, 0 is returned and *res is 1 for SET; 0 otherwise.
2869 *
2870 * In the event of failure, a negative value is returned and *res is
2871 * meaningless.
2872 *
2873 * Callers must make sure to hold nfs_sync_lock to prevent
2874 * ocfs2_delete_inode() on another node from accessing the same
2875 * suballocator concurrently.
2876 */
2877int ocfs2_test_inode_bit(struct ocfs2_super *osb, u64 blkno, int *res)
2878{
2879	int status;
2880	u64 group_blkno = 0;
2881	u16 suballoc_bit = 0, suballoc_slot = 0;
2882	struct inode *inode_alloc_inode;
2883	struct buffer_head *alloc_bh = NULL;
2884
2885	trace_ocfs2_test_inode_bit((unsigned long long)blkno);
2886
2887	status = ocfs2_get_suballoc_slot_bit(osb, blkno, &suballoc_slot,
2888					     &group_blkno, &suballoc_bit);
2889	if (status < 0) {
2890		mlog(ML_ERROR, "get alloc slot and bit failed %d\n", status);
2891		goto bail;
2892	}
2893
2894	inode_alloc_inode =
2895		ocfs2_get_system_file_inode(osb, INODE_ALLOC_SYSTEM_INODE,
2896					    suballoc_slot);
 
 
 
2897	if (!inode_alloc_inode) {
2898		/* the error code could be inaccurate, but we are not able to
2899		 * get the correct one. */
2900		status = -EINVAL;
2901		mlog(ML_ERROR, "unable to get alloc inode in slot %u\n",
2902		     (u32)suballoc_slot);
2903		goto bail;
2904	}
2905
2906	inode_lock(inode_alloc_inode);
2907	status = ocfs2_inode_lock(inode_alloc_inode, &alloc_bh, 0);
2908	if (status < 0) {
2909		inode_unlock(inode_alloc_inode);
2910		iput(inode_alloc_inode);
2911		mlog(ML_ERROR, "lock on alloc inode on slot %u failed %d\n",
2912		     (u32)suballoc_slot, status);
2913		goto bail;
2914	}
2915
2916	status = ocfs2_test_suballoc_bit(osb, inode_alloc_inode, alloc_bh,
2917					 group_blkno, blkno, suballoc_bit, res);
2918	if (status < 0)
2919		mlog(ML_ERROR, "test suballoc bit failed %d\n", status);
2920
2921	ocfs2_inode_unlock(inode_alloc_inode, 0);
2922	inode_unlock(inode_alloc_inode);
2923
2924	iput(inode_alloc_inode);
2925	brelse(alloc_bh);
2926bail:
2927	if (status)
2928		mlog_errno(status);
2929	return status;
2930}