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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}
v3.5.6
   1/* -*- mode: c; c-basic-offset: 8; -*-
   2 * vim: noexpandtab sw=8 ts=8 sts=0:
   3 *
   4 * suballoc.c
   5 *
   6 * metadata alloc and free
   7 * Inspired by ext3 block groups.
   8 *
   9 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
  10 *
  11 * This program is free software; you can redistribute it and/or
  12 * modify it under the terms of the GNU General Public
  13 * License as published by the Free Software Foundation; either
  14 * version 2 of the License, or (at your option) any later version.
  15 *
  16 * This program is distributed in the hope that it will be useful,
  17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19 * General Public License for more details.
  20 *
  21 * You should have received a copy of the GNU General Public
  22 * License along with this program; if not, write to the
  23 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  24 * Boston, MA 021110-1307, USA.
  25 */
  26
  27#include <linux/fs.h>
  28#include <linux/types.h>
  29#include <linux/slab.h>
  30#include <linux/highmem.h>
  31
  32#include <cluster/masklog.h>
  33
  34#include "ocfs2.h"
  35
  36#include "alloc.h"
  37#include "blockcheck.h"
  38#include "dlmglue.h"
  39#include "inode.h"
  40#include "journal.h"
  41#include "localalloc.h"
  42#include "suballoc.h"
  43#include "super.h"
  44#include "sysfile.h"
  45#include "uptodate.h"
  46#include "ocfs2_trace.h"
  47
  48#include "buffer_head_io.h"
  49
  50#define NOT_ALLOC_NEW_GROUP		0
  51#define ALLOC_NEW_GROUP			0x1
  52#define ALLOC_GROUPS_FROM_GLOBAL	0x2
  53
  54#define OCFS2_MAX_TO_STEAL		1024
  55
  56struct ocfs2_suballoc_result {
  57	u64		sr_bg_blkno;	/* The bg we allocated from.  Set
  58					   to 0 when a block group is
  59					   contiguous. */
  60	u64		sr_bg_stable_blkno; /*
  61					     * Doesn't change, always
  62					     * set to target block
  63					     * group descriptor
  64					     * block.
  65					     */
  66	u64		sr_blkno;	/* The first allocated block */
  67	unsigned int	sr_bit_offset;	/* The bit in the bg */
  68	unsigned int	sr_bits;	/* How many bits we claimed */
  69};
  70
  71static u64 ocfs2_group_from_res(struct ocfs2_suballoc_result *res)
  72{
  73	if (res->sr_blkno == 0)
  74		return 0;
  75
  76	if (res->sr_bg_blkno)
  77		return res->sr_bg_blkno;
  78
  79	return ocfs2_which_suballoc_group(res->sr_blkno, res->sr_bit_offset);
  80}
  81
  82static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg);
  83static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe);
  84static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl);
  85static int ocfs2_block_group_fill(handle_t *handle,
  86				  struct inode *alloc_inode,
  87				  struct buffer_head *bg_bh,
  88				  u64 group_blkno,
  89				  unsigned int group_clusters,
  90				  u16 my_chain,
  91				  struct ocfs2_chain_list *cl);
  92static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
  93				   struct inode *alloc_inode,
  94				   struct buffer_head *bh,
  95				   u64 max_block,
  96				   u64 *last_alloc_group,
  97				   int flags);
  98
  99static int ocfs2_cluster_group_search(struct inode *inode,
 100				      struct buffer_head *group_bh,
 101				      u32 bits_wanted, u32 min_bits,
 102				      u64 max_block,
 103				      struct ocfs2_suballoc_result *res);
 104static int ocfs2_block_group_search(struct inode *inode,
 105				    struct buffer_head *group_bh,
 106				    u32 bits_wanted, u32 min_bits,
 107				    u64 max_block,
 108				    struct ocfs2_suballoc_result *res);
 109static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
 110				     handle_t *handle,
 111				     u32 bits_wanted,
 112				     u32 min_bits,
 113				     struct ocfs2_suballoc_result *res);
 114static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
 115					 int nr);
 116static inline int ocfs2_block_group_set_bits(handle_t *handle,
 117					     struct inode *alloc_inode,
 118					     struct ocfs2_group_desc *bg,
 119					     struct buffer_head *group_bh,
 120					     unsigned int bit_off,
 121					     unsigned int num_bits);
 122static int ocfs2_relink_block_group(handle_t *handle,
 123				    struct inode *alloc_inode,
 124				    struct buffer_head *fe_bh,
 125				    struct buffer_head *bg_bh,
 126				    struct buffer_head *prev_bg_bh,
 127				    u16 chain);
 128static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
 129						     u32 wanted);
 130static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
 131						   u64 bg_blkno,
 132						   u16 bg_bit_off);
 133static inline void ocfs2_block_to_cluster_group(struct inode *inode,
 134						u64 data_blkno,
 135						u64 *bg_blkno,
 136						u16 *bg_bit_off);
 137static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
 138					     u32 bits_wanted, u64 max_block,
 139					     int flags,
 140					     struct ocfs2_alloc_context **ac);
 141
 142void ocfs2_free_ac_resource(struct ocfs2_alloc_context *ac)
 143{
 144	struct inode *inode = ac->ac_inode;
 145
 146	if (inode) {
 147		if (ac->ac_which != OCFS2_AC_USE_LOCAL)
 148			ocfs2_inode_unlock(inode, 1);
 149
 150		mutex_unlock(&inode->i_mutex);
 151
 152		iput(inode);
 153		ac->ac_inode = NULL;
 154	}
 155	brelse(ac->ac_bh);
 156	ac->ac_bh = NULL;
 157	ac->ac_resv = NULL;
 158	if (ac->ac_find_loc_priv) {
 159		kfree(ac->ac_find_loc_priv);
 160		ac->ac_find_loc_priv = NULL;
 161	}
 162}
 163
 164void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
 165{
 166	ocfs2_free_ac_resource(ac);
 167	kfree(ac);
 168}
 169
 170static u32 ocfs2_bits_per_group(struct ocfs2_chain_list *cl)
 171{
 172	return (u32)le16_to_cpu(cl->cl_cpg) * (u32)le16_to_cpu(cl->cl_bpc);
 173}
 174
 175#define do_error(fmt, ...)						\
 176	do{								\
 177		if (resize)					\
 178			mlog(ML_ERROR, fmt "\n", ##__VA_ARGS__);	\
 179		else							\
 180			ocfs2_error(sb, fmt, ##__VA_ARGS__);		\
 181	} while (0)
 182
 183static int ocfs2_validate_gd_self(struct super_block *sb,
 184				  struct buffer_head *bh,
 185				  int resize)
 186{
 187	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 188
 189	if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
 190		do_error("Group descriptor #%llu has bad signature %.*s",
 191			 (unsigned long long)bh->b_blocknr, 7,
 192			 gd->bg_signature);
 193		return -EINVAL;
 194	}
 195
 196	if (le64_to_cpu(gd->bg_blkno) != bh->b_blocknr) {
 197		do_error("Group descriptor #%llu has an invalid bg_blkno "
 198			 "of %llu",
 199			 (unsigned long long)bh->b_blocknr,
 200			 (unsigned long long)le64_to_cpu(gd->bg_blkno));
 201		return -EINVAL;
 202	}
 203
 204	if (le32_to_cpu(gd->bg_generation) != OCFS2_SB(sb)->fs_generation) {
 205		do_error("Group descriptor #%llu has an invalid "
 206			 "fs_generation of #%u",
 207			 (unsigned long long)bh->b_blocknr,
 208			 le32_to_cpu(gd->bg_generation));
 209		return -EINVAL;
 210	}
 211
 212	if (le16_to_cpu(gd->bg_free_bits_count) > le16_to_cpu(gd->bg_bits)) {
 213		do_error("Group descriptor #%llu has bit count %u but "
 214			 "claims that %u are free",
 215			 (unsigned long long)bh->b_blocknr,
 216			 le16_to_cpu(gd->bg_bits),
 217			 le16_to_cpu(gd->bg_free_bits_count));
 218		return -EINVAL;
 219	}
 220
 221	if (le16_to_cpu(gd->bg_bits) > (8 * le16_to_cpu(gd->bg_size))) {
 222		do_error("Group descriptor #%llu has bit count %u but "
 223			 "max bitmap bits of %u",
 224			 (unsigned long long)bh->b_blocknr,
 225			 le16_to_cpu(gd->bg_bits),
 226			 8 * le16_to_cpu(gd->bg_size));
 227		return -EINVAL;
 228	}
 229
 230	return 0;
 231}
 232
 233static int ocfs2_validate_gd_parent(struct super_block *sb,
 234				    struct ocfs2_dinode *di,
 235				    struct buffer_head *bh,
 236				    int resize)
 237{
 238	unsigned int max_bits;
 239	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 240
 241	if (di->i_blkno != gd->bg_parent_dinode) {
 242		do_error("Group descriptor #%llu has bad parent "
 243			 "pointer (%llu, expected %llu)",
 244			 (unsigned long long)bh->b_blocknr,
 245			 (unsigned long long)le64_to_cpu(gd->bg_parent_dinode),
 246			 (unsigned long long)le64_to_cpu(di->i_blkno));
 247		return -EINVAL;
 248	}
 249
 250	max_bits = le16_to_cpu(di->id2.i_chain.cl_cpg) * le16_to_cpu(di->id2.i_chain.cl_bpc);
 251	if (le16_to_cpu(gd->bg_bits) > max_bits) {
 252		do_error("Group descriptor #%llu has bit count of %u",
 253			 (unsigned long long)bh->b_blocknr,
 254			 le16_to_cpu(gd->bg_bits));
 255		return -EINVAL;
 256	}
 257
 258	/* In resize, we may meet the case bg_chain == cl_next_free_rec. */
 259	if ((le16_to_cpu(gd->bg_chain) >
 260	     le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) ||
 261	    ((le16_to_cpu(gd->bg_chain) ==
 262	     le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) && !resize)) {
 263		do_error("Group descriptor #%llu has bad chain %u",
 264			 (unsigned long long)bh->b_blocknr,
 265			 le16_to_cpu(gd->bg_chain));
 266		return -EINVAL;
 267	}
 268
 269	return 0;
 270}
 271
 272#undef do_error
 273
 274/*
 275 * This version only prints errors.  It does not fail the filesystem, and
 276 * exists only for resize.
 277 */
 278int ocfs2_check_group_descriptor(struct super_block *sb,
 279				 struct ocfs2_dinode *di,
 280				 struct buffer_head *bh)
 281{
 282	int rc;
 283	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 284
 285	BUG_ON(!buffer_uptodate(bh));
 286
 287	/*
 288	 * If the ecc fails, we return the error but otherwise
 289	 * leave the filesystem running.  We know any error is
 290	 * local to this block.
 291	 */
 292	rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
 293	if (rc) {
 294		mlog(ML_ERROR,
 295		     "Checksum failed for group descriptor %llu\n",
 296		     (unsigned long long)bh->b_blocknr);
 297	} else
 298		rc = ocfs2_validate_gd_self(sb, bh, 1);
 299	if (!rc)
 300		rc = ocfs2_validate_gd_parent(sb, di, bh, 1);
 301
 302	return rc;
 303}
 304
 305static int ocfs2_validate_group_descriptor(struct super_block *sb,
 306					   struct buffer_head *bh)
 307{
 308	int rc;
 309	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 310
 311	trace_ocfs2_validate_group_descriptor(
 312					(unsigned long long)bh->b_blocknr);
 313
 314	BUG_ON(!buffer_uptodate(bh));
 315
 316	/*
 317	 * If the ecc fails, we return the error but otherwise
 318	 * leave the filesystem running.  We know any error is
 319	 * local to this block.
 320	 */
 321	rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
 322	if (rc)
 323		return rc;
 324
 325	/*
 326	 * Errors after here are fatal.
 327	 */
 328
 329	return ocfs2_validate_gd_self(sb, bh, 0);
 330}
 331
 332int ocfs2_read_group_descriptor(struct inode *inode, struct ocfs2_dinode *di,
 333				u64 gd_blkno, struct buffer_head **bh)
 334{
 335	int rc;
 336	struct buffer_head *tmp = *bh;
 337
 338	rc = ocfs2_read_block(INODE_CACHE(inode), gd_blkno, &tmp,
 339			      ocfs2_validate_group_descriptor);
 340	if (rc)
 341		goto out;
 342
 343	rc = ocfs2_validate_gd_parent(inode->i_sb, di, tmp, 0);
 344	if (rc) {
 345		brelse(tmp);
 346		goto out;
 347	}
 348
 349	/* If ocfs2_read_block() got us a new bh, pass it up. */
 350	if (!*bh)
 351		*bh = tmp;
 352
 353out:
 354	return rc;
 355}
 356
 357static void ocfs2_bg_discontig_add_extent(struct ocfs2_super *osb,
 358					  struct ocfs2_group_desc *bg,
 359					  struct ocfs2_chain_list *cl,
 360					  u64 p_blkno, unsigned int clusters)
 361{
 362	struct ocfs2_extent_list *el = &bg->bg_list;
 363	struct ocfs2_extent_rec *rec;
 364
 365	BUG_ON(!ocfs2_supports_discontig_bg(osb));
 366	if (!el->l_next_free_rec)
 367		el->l_count = cpu_to_le16(ocfs2_extent_recs_per_gd(osb->sb));
 368	rec = &el->l_recs[le16_to_cpu(el->l_next_free_rec)];
 369	rec->e_blkno = cpu_to_le64(p_blkno);
 370	rec->e_cpos = cpu_to_le32(le16_to_cpu(bg->bg_bits) /
 371				  le16_to_cpu(cl->cl_bpc));
 372	rec->e_leaf_clusters = cpu_to_le16(clusters);
 373	le16_add_cpu(&bg->bg_bits, clusters * le16_to_cpu(cl->cl_bpc));
 374	le16_add_cpu(&bg->bg_free_bits_count,
 375		     clusters * le16_to_cpu(cl->cl_bpc));
 376	le16_add_cpu(&el->l_next_free_rec, 1);
 377}
 378
 379static int ocfs2_block_group_fill(handle_t *handle,
 380				  struct inode *alloc_inode,
 381				  struct buffer_head *bg_bh,
 382				  u64 group_blkno,
 383				  unsigned int group_clusters,
 384				  u16 my_chain,
 385				  struct ocfs2_chain_list *cl)
 386{
 387	int status = 0;
 388	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 389	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 390	struct super_block * sb = alloc_inode->i_sb;
 391
 392	if (((unsigned long long) bg_bh->b_blocknr) != group_blkno) {
 393		ocfs2_error(alloc_inode->i_sb, "group block (%llu) != "
 394			    "b_blocknr (%llu)",
 395			    (unsigned long long)group_blkno,
 396			    (unsigned long long) bg_bh->b_blocknr);
 397		status = -EIO;
 398		goto bail;
 399	}
 400
 401	status = ocfs2_journal_access_gd(handle,
 402					 INODE_CACHE(alloc_inode),
 403					 bg_bh,
 404					 OCFS2_JOURNAL_ACCESS_CREATE);
 405	if (status < 0) {
 406		mlog_errno(status);
 407		goto bail;
 408	}
 409
 410	memset(bg, 0, sb->s_blocksize);
 411	strcpy(bg->bg_signature, OCFS2_GROUP_DESC_SIGNATURE);
 412	bg->bg_generation = cpu_to_le32(OCFS2_SB(sb)->fs_generation);
 413	bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb, 1,
 414						osb->s_feature_incompat));
 415	bg->bg_chain = cpu_to_le16(my_chain);
 416	bg->bg_next_group = cl->cl_recs[my_chain].c_blkno;
 417	bg->bg_parent_dinode = cpu_to_le64(OCFS2_I(alloc_inode)->ip_blkno);
 418	bg->bg_blkno = cpu_to_le64(group_blkno);
 419	if (group_clusters == le16_to_cpu(cl->cl_cpg))
 420		bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
 421	else
 422		ocfs2_bg_discontig_add_extent(osb, bg, cl, group_blkno,
 423					      group_clusters);
 424
 425	/* set the 1st bit in the bitmap to account for the descriptor block */
 426	ocfs2_set_bit(0, (unsigned long *)bg->bg_bitmap);
 427	bg->bg_free_bits_count = cpu_to_le16(le16_to_cpu(bg->bg_bits) - 1);
 428
 429	ocfs2_journal_dirty(handle, bg_bh);
 430
 431	/* There is no need to zero out or otherwise initialize the
 432	 * other blocks in a group - All valid FS metadata in a block
 433	 * group stores the superblock fs_generation value at
 434	 * allocation time. */
 435
 436bail:
 437	if (status)
 438		mlog_errno(status);
 439	return status;
 440}
 441
 442static inline u16 ocfs2_find_smallest_chain(struct ocfs2_chain_list *cl)
 443{
 444	u16 curr, best;
 445
 446	best = curr = 0;
 447	while (curr < le16_to_cpu(cl->cl_count)) {
 448		if (le32_to_cpu(cl->cl_recs[best].c_total) >
 449		    le32_to_cpu(cl->cl_recs[curr].c_total))
 450			best = curr;
 451		curr++;
 452	}
 453	return best;
 454}
 455
 456static struct buffer_head *
 457ocfs2_block_group_alloc_contig(struct ocfs2_super *osb, handle_t *handle,
 458			       struct inode *alloc_inode,
 459			       struct ocfs2_alloc_context *ac,
 460			       struct ocfs2_chain_list *cl)
 461{
 462	int status;
 463	u32 bit_off, num_bits;
 464	u64 bg_blkno;
 465	struct buffer_head *bg_bh;
 466	unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
 467
 468	status = ocfs2_claim_clusters(handle, ac,
 469				      le16_to_cpu(cl->cl_cpg), &bit_off,
 470				      &num_bits);
 471	if (status < 0) {
 472		if (status != -ENOSPC)
 473			mlog_errno(status);
 474		goto bail;
 475	}
 476
 477	/* setup the group */
 478	bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 479	trace_ocfs2_block_group_alloc_contig(
 480	     (unsigned long long)bg_blkno, alloc_rec);
 481
 482	bg_bh = sb_getblk(osb->sb, bg_blkno);
 483	if (!bg_bh) {
 484		status = -EIO;
 485		mlog_errno(status);
 486		goto bail;
 487	}
 488	ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
 489
 490	status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
 491					bg_blkno, num_bits, alloc_rec, cl);
 492	if (status < 0) {
 493		brelse(bg_bh);
 494		mlog_errno(status);
 495	}
 496
 497bail:
 498	return status ? ERR_PTR(status) : bg_bh;
 499}
 500
 501static int ocfs2_block_group_claim_bits(struct ocfs2_super *osb,
 502					handle_t *handle,
 503					struct ocfs2_alloc_context *ac,
 504					unsigned int min_bits,
 505					u32 *bit_off, u32 *num_bits)
 506{
 507	int status = 0;
 508
 509	while (min_bits) {
 510		status = ocfs2_claim_clusters(handle, ac, min_bits,
 511					      bit_off, num_bits);
 512		if (status != -ENOSPC)
 513			break;
 514
 515		min_bits >>= 1;
 516	}
 517
 518	return status;
 519}
 520
 521static int ocfs2_block_group_grow_discontig(handle_t *handle,
 522					    struct inode *alloc_inode,
 523					    struct buffer_head *bg_bh,
 524					    struct ocfs2_alloc_context *ac,
 525					    struct ocfs2_chain_list *cl,
 526					    unsigned int min_bits)
 527{
 528	int status;
 529	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 530	struct ocfs2_group_desc *bg =
 531		(struct ocfs2_group_desc *)bg_bh->b_data;
 532	unsigned int needed = le16_to_cpu(cl->cl_cpg) -
 533			 le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
 534	u32 p_cpos, clusters;
 535	u64 p_blkno;
 536	struct ocfs2_extent_list *el = &bg->bg_list;
 537
 538	status = ocfs2_journal_access_gd(handle,
 539					 INODE_CACHE(alloc_inode),
 540					 bg_bh,
 541					 OCFS2_JOURNAL_ACCESS_CREATE);
 542	if (status < 0) {
 543		mlog_errno(status);
 544		goto bail;
 545	}
 546
 547	while ((needed > 0) && (le16_to_cpu(el->l_next_free_rec) <
 548				le16_to_cpu(el->l_count))) {
 549		if (min_bits > needed)
 550			min_bits = needed;
 551		status = ocfs2_block_group_claim_bits(osb, handle, ac,
 552						      min_bits, &p_cpos,
 553						      &clusters);
 554		if (status < 0) {
 555			if (status != -ENOSPC)
 556				mlog_errno(status);
 557			goto bail;
 558		}
 559		p_blkno = ocfs2_clusters_to_blocks(osb->sb, p_cpos);
 560		ocfs2_bg_discontig_add_extent(osb, bg, cl, p_blkno,
 561					      clusters);
 562
 563		min_bits = clusters;
 564		needed = le16_to_cpu(cl->cl_cpg) -
 565			 le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
 566	}
 567
 568	if (needed > 0) {
 569		/*
 570		 * We have used up all the extent rec but can't fill up
 571		 * the cpg. So bail out.
 572		 */
 573		status = -ENOSPC;
 574		goto bail;
 575	}
 576
 577	ocfs2_journal_dirty(handle, bg_bh);
 578
 579bail:
 580	return status;
 581}
 582
 583static void ocfs2_bg_alloc_cleanup(handle_t *handle,
 584				   struct ocfs2_alloc_context *cluster_ac,
 585				   struct inode *alloc_inode,
 586				   struct buffer_head *bg_bh)
 587{
 588	int i, ret;
 589	struct ocfs2_group_desc *bg;
 590	struct ocfs2_extent_list *el;
 591	struct ocfs2_extent_rec *rec;
 592
 593	if (!bg_bh)
 594		return;
 595
 596	bg = (struct ocfs2_group_desc *)bg_bh->b_data;
 597	el = &bg->bg_list;
 598	for (i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
 599		rec = &el->l_recs[i];
 600		ret = ocfs2_free_clusters(handle, cluster_ac->ac_inode,
 601					  cluster_ac->ac_bh,
 602					  le64_to_cpu(rec->e_blkno),
 603					  le16_to_cpu(rec->e_leaf_clusters));
 604		if (ret)
 605			mlog_errno(ret);
 606		/* Try all the clusters to free */
 607	}
 608
 609	ocfs2_remove_from_cache(INODE_CACHE(alloc_inode), bg_bh);
 610	brelse(bg_bh);
 611}
 612
 613static struct buffer_head *
 614ocfs2_block_group_alloc_discontig(handle_t *handle,
 615				  struct inode *alloc_inode,
 616				  struct ocfs2_alloc_context *ac,
 617				  struct ocfs2_chain_list *cl)
 618{
 619	int status;
 620	u32 bit_off, num_bits;
 621	u64 bg_blkno;
 622	unsigned int min_bits = le16_to_cpu(cl->cl_cpg) >> 1;
 623	struct buffer_head *bg_bh = NULL;
 624	unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
 625	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 626
 627	if (!ocfs2_supports_discontig_bg(osb)) {
 628		status = -ENOSPC;
 629		goto bail;
 630	}
 631
 632	status = ocfs2_extend_trans(handle,
 633				    ocfs2_calc_bg_discontig_credits(osb->sb));
 634	if (status) {
 635		mlog_errno(status);
 636		goto bail;
 637	}
 638
 639	/*
 640	 * We're going to be grabbing from multiple cluster groups.
 641	 * We don't have enough credits to relink them all, and the
 642	 * cluster groups will be staying in cache for the duration of
 643	 * this operation.
 644	 */
 645	ac->ac_allow_chain_relink = 0;
 646
 647	/* Claim the first region */
 648	status = ocfs2_block_group_claim_bits(osb, handle, ac, min_bits,
 649					      &bit_off, &num_bits);
 650	if (status < 0) {
 651		if (status != -ENOSPC)
 652			mlog_errno(status);
 653		goto bail;
 654	}
 655	min_bits = num_bits;
 656
 657	/* setup the group */
 658	bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 659	trace_ocfs2_block_group_alloc_discontig(
 660				(unsigned long long)bg_blkno, alloc_rec);
 661
 662	bg_bh = sb_getblk(osb->sb, bg_blkno);
 663	if (!bg_bh) {
 664		status = -EIO;
 665		mlog_errno(status);
 666		goto bail;
 667	}
 668	ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
 669
 670	status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
 671					bg_blkno, num_bits, alloc_rec, cl);
 672	if (status < 0) {
 673		mlog_errno(status);
 674		goto bail;
 675	}
 676
 677	status = ocfs2_block_group_grow_discontig(handle, alloc_inode,
 678						  bg_bh, ac, cl, min_bits);
 679	if (status)
 680		mlog_errno(status);
 681
 682bail:
 683	if (status)
 684		ocfs2_bg_alloc_cleanup(handle, ac, alloc_inode, bg_bh);
 685	return status ? ERR_PTR(status) : bg_bh;
 686}
 687
 688/*
 689 * We expect the block group allocator to already be locked.
 690 */
 691static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
 692				   struct inode *alloc_inode,
 693				   struct buffer_head *bh,
 694				   u64 max_block,
 695				   u64 *last_alloc_group,
 696				   int flags)
 697{
 698	int status, credits;
 699	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) bh->b_data;
 700	struct ocfs2_chain_list *cl;
 701	struct ocfs2_alloc_context *ac = NULL;
 702	handle_t *handle = NULL;
 703	u16 alloc_rec;
 704	struct buffer_head *bg_bh = NULL;
 705	struct ocfs2_group_desc *bg;
 706
 707	BUG_ON(ocfs2_is_cluster_bitmap(alloc_inode));
 708
 709	cl = &fe->id2.i_chain;
 710	status = ocfs2_reserve_clusters_with_limit(osb,
 711						   le16_to_cpu(cl->cl_cpg),
 712						   max_block, flags, &ac);
 713	if (status < 0) {
 714		if (status != -ENOSPC)
 715			mlog_errno(status);
 716		goto bail;
 717	}
 718
 719	credits = ocfs2_calc_group_alloc_credits(osb->sb,
 720						 le16_to_cpu(cl->cl_cpg));
 721	handle = ocfs2_start_trans(osb, credits);
 722	if (IS_ERR(handle)) {
 723		status = PTR_ERR(handle);
 724		handle = NULL;
 725		mlog_errno(status);
 726		goto bail;
 727	}
 728
 729	if (last_alloc_group && *last_alloc_group != 0) {
 730		trace_ocfs2_block_group_alloc(
 731				(unsigned long long)*last_alloc_group);
 732		ac->ac_last_group = *last_alloc_group;
 733	}
 734
 735	bg_bh = ocfs2_block_group_alloc_contig(osb, handle, alloc_inode,
 736					       ac, cl);
 737	if (IS_ERR(bg_bh) && (PTR_ERR(bg_bh) == -ENOSPC))
 738		bg_bh = ocfs2_block_group_alloc_discontig(handle,
 739							  alloc_inode,
 740							  ac, cl);
 741	if (IS_ERR(bg_bh)) {
 742		status = PTR_ERR(bg_bh);
 743		bg_bh = NULL;
 744		if (status != -ENOSPC)
 745			mlog_errno(status);
 746		goto bail;
 747	}
 748	bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 749
 750	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
 751					 bh, OCFS2_JOURNAL_ACCESS_WRITE);
 752	if (status < 0) {
 753		mlog_errno(status);
 754		goto bail;
 755	}
 756
 757	alloc_rec = le16_to_cpu(bg->bg_chain);
 758	le32_add_cpu(&cl->cl_recs[alloc_rec].c_free,
 759		     le16_to_cpu(bg->bg_free_bits_count));
 760	le32_add_cpu(&cl->cl_recs[alloc_rec].c_total,
 761		     le16_to_cpu(bg->bg_bits));
 762	cl->cl_recs[alloc_rec].c_blkno = bg->bg_blkno;
 763	if (le16_to_cpu(cl->cl_next_free_rec) < le16_to_cpu(cl->cl_count))
 764		le16_add_cpu(&cl->cl_next_free_rec, 1);
 765
 766	le32_add_cpu(&fe->id1.bitmap1.i_used, le16_to_cpu(bg->bg_bits) -
 767					le16_to_cpu(bg->bg_free_bits_count));
 768	le32_add_cpu(&fe->id1.bitmap1.i_total, le16_to_cpu(bg->bg_bits));
 769	le32_add_cpu(&fe->i_clusters, le16_to_cpu(cl->cl_cpg));
 770
 771	ocfs2_journal_dirty(handle, bh);
 772
 773	spin_lock(&OCFS2_I(alloc_inode)->ip_lock);
 774	OCFS2_I(alloc_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
 775	fe->i_size = cpu_to_le64(ocfs2_clusters_to_bytes(alloc_inode->i_sb,
 776					     le32_to_cpu(fe->i_clusters)));
 777	spin_unlock(&OCFS2_I(alloc_inode)->ip_lock);
 778	i_size_write(alloc_inode, le64_to_cpu(fe->i_size));
 779	alloc_inode->i_blocks = ocfs2_inode_sector_count(alloc_inode);
 
 780
 781	status = 0;
 782
 783	/* save the new last alloc group so that the caller can cache it. */
 784	if (last_alloc_group)
 785		*last_alloc_group = ac->ac_last_group;
 786
 787bail:
 788	if (handle)
 789		ocfs2_commit_trans(osb, handle);
 790
 791	if (ac)
 792		ocfs2_free_alloc_context(ac);
 793
 794	brelse(bg_bh);
 795
 796	if (status)
 797		mlog_errno(status);
 798	return status;
 799}
 800
 801static int ocfs2_reserve_suballoc_bits(struct ocfs2_super *osb,
 802				       struct ocfs2_alloc_context *ac,
 803				       int type,
 804				       u32 slot,
 805				       u64 *last_alloc_group,
 806				       int flags)
 807{
 808	int status;
 809	u32 bits_wanted = ac->ac_bits_wanted;
 810	struct inode *alloc_inode;
 811	struct buffer_head *bh = NULL;
 812	struct ocfs2_dinode *fe;
 813	u32 free_bits;
 814
 815	alloc_inode = ocfs2_get_system_file_inode(osb, type, slot);
 816	if (!alloc_inode) {
 817		mlog_errno(-EINVAL);
 818		return -EINVAL;
 819	}
 820
 821	mutex_lock(&alloc_inode->i_mutex);
 822
 823	status = ocfs2_inode_lock(alloc_inode, &bh, 1);
 824	if (status < 0) {
 825		mutex_unlock(&alloc_inode->i_mutex);
 826		iput(alloc_inode);
 827
 828		mlog_errno(status);
 829		return status;
 830	}
 831
 832	ac->ac_inode = alloc_inode;
 833	ac->ac_alloc_slot = slot;
 834
 835	fe = (struct ocfs2_dinode *) bh->b_data;
 836
 837	/* The bh was validated by the inode read inside
 838	 * ocfs2_inode_lock().  Any corruption is a code bug. */
 839	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
 840
 841	if (!(fe->i_flags & cpu_to_le32(OCFS2_CHAIN_FL))) {
 842		ocfs2_error(alloc_inode->i_sb, "Invalid chain allocator %llu",
 843			    (unsigned long long)le64_to_cpu(fe->i_blkno));
 844		status = -EIO;
 845		goto bail;
 846	}
 847
 848	free_bits = le32_to_cpu(fe->id1.bitmap1.i_total) -
 849		le32_to_cpu(fe->id1.bitmap1.i_used);
 850
 851	if (bits_wanted > free_bits) {
 852		/* cluster bitmap never grows */
 853		if (ocfs2_is_cluster_bitmap(alloc_inode)) {
 854			trace_ocfs2_reserve_suballoc_bits_nospc(bits_wanted,
 855								free_bits);
 856			status = -ENOSPC;
 857			goto bail;
 858		}
 859
 860		if (!(flags & ALLOC_NEW_GROUP)) {
 861			trace_ocfs2_reserve_suballoc_bits_no_new_group(
 862						slot, bits_wanted, free_bits);
 863			status = -ENOSPC;
 864			goto bail;
 865		}
 866
 867		status = ocfs2_block_group_alloc(osb, alloc_inode, bh,
 868						 ac->ac_max_block,
 869						 last_alloc_group, flags);
 870		if (status < 0) {
 871			if (status != -ENOSPC)
 872				mlog_errno(status);
 873			goto bail;
 874		}
 875		atomic_inc(&osb->alloc_stats.bg_extends);
 876
 877		/* You should never ask for this much metadata */
 878		BUG_ON(bits_wanted >
 879		       (le32_to_cpu(fe->id1.bitmap1.i_total)
 880			- le32_to_cpu(fe->id1.bitmap1.i_used)));
 881	}
 882
 883	get_bh(bh);
 884	ac->ac_bh = bh;
 885bail:
 886	brelse(bh);
 887
 888	if (status)
 889		mlog_errno(status);
 890	return status;
 891}
 892
 893static void ocfs2_init_inode_steal_slot(struct ocfs2_super *osb)
 894{
 895	spin_lock(&osb->osb_lock);
 896	osb->s_inode_steal_slot = OCFS2_INVALID_SLOT;
 897	spin_unlock(&osb->osb_lock);
 898	atomic_set(&osb->s_num_inodes_stolen, 0);
 899}
 900
 901static void ocfs2_init_meta_steal_slot(struct ocfs2_super *osb)
 902{
 903	spin_lock(&osb->osb_lock);
 904	osb->s_meta_steal_slot = OCFS2_INVALID_SLOT;
 905	spin_unlock(&osb->osb_lock);
 906	atomic_set(&osb->s_num_meta_stolen, 0);
 907}
 908
 909void ocfs2_init_steal_slots(struct ocfs2_super *osb)
 910{
 911	ocfs2_init_inode_steal_slot(osb);
 912	ocfs2_init_meta_steal_slot(osb);
 913}
 914
 915static void __ocfs2_set_steal_slot(struct ocfs2_super *osb, int slot, int type)
 916{
 917	spin_lock(&osb->osb_lock);
 918	if (type == INODE_ALLOC_SYSTEM_INODE)
 919		osb->s_inode_steal_slot = slot;
 920	else if (type == EXTENT_ALLOC_SYSTEM_INODE)
 921		osb->s_meta_steal_slot = slot;
 922	spin_unlock(&osb->osb_lock);
 923}
 924
 925static int __ocfs2_get_steal_slot(struct ocfs2_super *osb, int type)
 926{
 927	int slot = OCFS2_INVALID_SLOT;
 928
 929	spin_lock(&osb->osb_lock);
 930	if (type == INODE_ALLOC_SYSTEM_INODE)
 931		slot = osb->s_inode_steal_slot;
 932	else if (type == EXTENT_ALLOC_SYSTEM_INODE)
 933		slot = osb->s_meta_steal_slot;
 934	spin_unlock(&osb->osb_lock);
 935
 936	return slot;
 937}
 938
 939static int ocfs2_get_inode_steal_slot(struct ocfs2_super *osb)
 940{
 941	return __ocfs2_get_steal_slot(osb, INODE_ALLOC_SYSTEM_INODE);
 942}
 943
 944static int ocfs2_get_meta_steal_slot(struct ocfs2_super *osb)
 945{
 946	return __ocfs2_get_steal_slot(osb, EXTENT_ALLOC_SYSTEM_INODE);
 947}
 948
 949static int ocfs2_steal_resource(struct ocfs2_super *osb,
 950				struct ocfs2_alloc_context *ac,
 951				int type)
 952{
 953	int i, status = -ENOSPC;
 954	int slot = __ocfs2_get_steal_slot(osb, type);
 955
 956	/* Start to steal resource from the first slot after ours. */
 957	if (slot == OCFS2_INVALID_SLOT)
 958		slot = osb->slot_num + 1;
 959
 960	for (i = 0; i < osb->max_slots; i++, slot++) {
 961		if (slot == osb->max_slots)
 962			slot = 0;
 963
 964		if (slot == osb->slot_num)
 965			continue;
 966
 967		status = ocfs2_reserve_suballoc_bits(osb, ac,
 968						     type,
 969						     (u32)slot, NULL,
 970						     NOT_ALLOC_NEW_GROUP);
 971		if (status >= 0) {
 972			__ocfs2_set_steal_slot(osb, slot, type);
 973			break;
 974		}
 975
 976		ocfs2_free_ac_resource(ac);
 977	}
 978
 979	return status;
 980}
 981
 982static int ocfs2_steal_inode(struct ocfs2_super *osb,
 983			     struct ocfs2_alloc_context *ac)
 984{
 985	return ocfs2_steal_resource(osb, ac, INODE_ALLOC_SYSTEM_INODE);
 986}
 987
 988static int ocfs2_steal_meta(struct ocfs2_super *osb,
 989			    struct ocfs2_alloc_context *ac)
 990{
 991	return ocfs2_steal_resource(osb, ac, EXTENT_ALLOC_SYSTEM_INODE);
 992}
 993
 994int ocfs2_reserve_new_metadata_blocks(struct ocfs2_super *osb,
 995				      int blocks,
 996				      struct ocfs2_alloc_context **ac)
 997{
 998	int status;
 999	int slot = ocfs2_get_meta_steal_slot(osb);
1000
1001	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1002	if (!(*ac)) {
1003		status = -ENOMEM;
1004		mlog_errno(status);
1005		goto bail;
1006	}
1007
1008	(*ac)->ac_bits_wanted = blocks;
1009	(*ac)->ac_which = OCFS2_AC_USE_META;
1010	(*ac)->ac_group_search = ocfs2_block_group_search;
1011
1012	if (slot != OCFS2_INVALID_SLOT &&
1013		atomic_read(&osb->s_num_meta_stolen) < OCFS2_MAX_TO_STEAL)
1014		goto extent_steal;
1015
1016	atomic_set(&osb->s_num_meta_stolen, 0);
1017	status = ocfs2_reserve_suballoc_bits(osb, (*ac),
1018					     EXTENT_ALLOC_SYSTEM_INODE,
1019					     (u32)osb->slot_num, NULL,
1020					     ALLOC_GROUPS_FROM_GLOBAL|ALLOC_NEW_GROUP);
1021
1022
1023	if (status >= 0) {
1024		status = 0;
1025		if (slot != OCFS2_INVALID_SLOT)
1026			ocfs2_init_meta_steal_slot(osb);
1027		goto bail;
1028	} else if (status < 0 && status != -ENOSPC) {
1029		mlog_errno(status);
1030		goto bail;
1031	}
1032
1033	ocfs2_free_ac_resource(*ac);
1034
1035extent_steal:
1036	status = ocfs2_steal_meta(osb, *ac);
1037	atomic_inc(&osb->s_num_meta_stolen);
1038	if (status < 0) {
1039		if (status != -ENOSPC)
1040			mlog_errno(status);
1041		goto bail;
1042	}
1043
1044	status = 0;
1045bail:
1046	if ((status < 0) && *ac) {
1047		ocfs2_free_alloc_context(*ac);
1048		*ac = NULL;
1049	}
1050
1051	if (status)
1052		mlog_errno(status);
1053	return status;
1054}
1055
1056int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
1057			       struct ocfs2_extent_list *root_el,
1058			       struct ocfs2_alloc_context **ac)
1059{
1060	return ocfs2_reserve_new_metadata_blocks(osb,
1061					ocfs2_extend_meta_needed(root_el),
1062					ac);
1063}
1064
1065int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
1066			    struct ocfs2_alloc_context **ac)
1067{
1068	int status;
1069	int slot = ocfs2_get_inode_steal_slot(osb);
1070	u64 alloc_group;
1071
1072	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1073	if (!(*ac)) {
1074		status = -ENOMEM;
1075		mlog_errno(status);
1076		goto bail;
1077	}
1078
1079	(*ac)->ac_bits_wanted = 1;
1080	(*ac)->ac_which = OCFS2_AC_USE_INODE;
1081
1082	(*ac)->ac_group_search = ocfs2_block_group_search;
1083
1084	/*
1085	 * stat(2) can't handle i_ino > 32bits, so we tell the
1086	 * lower levels not to allocate us a block group past that
1087	 * limit.  The 'inode64' mount option avoids this behavior.
1088	 */
1089	if (!(osb->s_mount_opt & OCFS2_MOUNT_INODE64))
1090		(*ac)->ac_max_block = (u32)~0U;
1091
1092	/*
1093	 * slot is set when we successfully steal inode from other nodes.
1094	 * It is reset in 3 places:
1095	 * 1. when we flush the truncate log
1096	 * 2. when we complete local alloc recovery.
1097	 * 3. when we successfully allocate from our own slot.
1098	 * After it is set, we will go on stealing inodes until we find the
1099	 * need to check our slots to see whether there is some space for us.
1100	 */
1101	if (slot != OCFS2_INVALID_SLOT &&
1102	    atomic_read(&osb->s_num_inodes_stolen) < OCFS2_MAX_TO_STEAL)
1103		goto inode_steal;
1104
1105	atomic_set(&osb->s_num_inodes_stolen, 0);
1106	alloc_group = osb->osb_inode_alloc_group;
1107	status = ocfs2_reserve_suballoc_bits(osb, *ac,
1108					     INODE_ALLOC_SYSTEM_INODE,
1109					     (u32)osb->slot_num,
1110					     &alloc_group,
1111					     ALLOC_NEW_GROUP |
1112					     ALLOC_GROUPS_FROM_GLOBAL);
1113	if (status >= 0) {
1114		status = 0;
1115
1116		spin_lock(&osb->osb_lock);
1117		osb->osb_inode_alloc_group = alloc_group;
1118		spin_unlock(&osb->osb_lock);
1119		trace_ocfs2_reserve_new_inode_new_group(
1120			(unsigned long long)alloc_group);
1121
1122		/*
1123		 * Some inodes must be freed by us, so try to allocate
1124		 * from our own next time.
1125		 */
1126		if (slot != OCFS2_INVALID_SLOT)
1127			ocfs2_init_inode_steal_slot(osb);
1128		goto bail;
1129	} else if (status < 0 && status != -ENOSPC) {
1130		mlog_errno(status);
1131		goto bail;
1132	}
1133
1134	ocfs2_free_ac_resource(*ac);
1135
1136inode_steal:
1137	status = ocfs2_steal_inode(osb, *ac);
1138	atomic_inc(&osb->s_num_inodes_stolen);
1139	if (status < 0) {
1140		if (status != -ENOSPC)
1141			mlog_errno(status);
1142		goto bail;
1143	}
1144
1145	status = 0;
1146bail:
1147	if ((status < 0) && *ac) {
1148		ocfs2_free_alloc_context(*ac);
1149		*ac = NULL;
1150	}
1151
1152	if (status)
1153		mlog_errno(status);
1154	return status;
1155}
1156
1157/* local alloc code has to do the same thing, so rather than do this
1158 * twice.. */
1159int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
1160				      struct ocfs2_alloc_context *ac)
1161{
1162	int status;
1163
1164	ac->ac_which = OCFS2_AC_USE_MAIN;
1165	ac->ac_group_search = ocfs2_cluster_group_search;
1166
1167	status = ocfs2_reserve_suballoc_bits(osb, ac,
1168					     GLOBAL_BITMAP_SYSTEM_INODE,
1169					     OCFS2_INVALID_SLOT, NULL,
1170					     ALLOC_NEW_GROUP);
1171	if (status < 0 && status != -ENOSPC) {
1172		mlog_errno(status);
1173		goto bail;
1174	}
1175
1176bail:
1177	return status;
1178}
1179
1180/* Callers don't need to care which bitmap (local alloc or main) to
1181 * use so we figure it out for them, but unfortunately this clutters
1182 * things a bit. */
1183static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
1184					     u32 bits_wanted, u64 max_block,
1185					     int flags,
1186					     struct ocfs2_alloc_context **ac)
1187{
1188	int status;
 
1189
1190	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1191	if (!(*ac)) {
1192		status = -ENOMEM;
1193		mlog_errno(status);
1194		goto bail;
1195	}
1196
1197	(*ac)->ac_bits_wanted = bits_wanted;
1198	(*ac)->ac_max_block = max_block;
1199
1200	status = -ENOSPC;
1201	if (!(flags & ALLOC_GROUPS_FROM_GLOBAL) &&
1202	    ocfs2_alloc_should_use_local(osb, bits_wanted)) {
1203		status = ocfs2_reserve_local_alloc_bits(osb,
1204							bits_wanted,
1205							*ac);
1206		if ((status < 0) && (status != -ENOSPC)) {
1207			mlog_errno(status);
1208			goto bail;
1209		}
1210	}
1211
1212	if (status == -ENOSPC) {
 
1213		status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1214		if (status < 0) {
1215			if (status != -ENOSPC)
1216				mlog_errno(status);
1217			goto bail;
1218		}
1219	}
1220
1221	status = 0;
1222bail:
1223	if ((status < 0) && *ac) {
1224		ocfs2_free_alloc_context(*ac);
1225		*ac = NULL;
1226	}
1227
1228	if (status)
1229		mlog_errno(status);
1230	return status;
1231}
1232
1233int ocfs2_reserve_clusters(struct ocfs2_super *osb,
1234			   u32 bits_wanted,
1235			   struct ocfs2_alloc_context **ac)
1236{
1237	return ocfs2_reserve_clusters_with_limit(osb, bits_wanted, 0,
1238						 ALLOC_NEW_GROUP, ac);
1239}
1240
1241/*
1242 * More or less lifted from ext3. I'll leave their description below:
1243 *
1244 * "For ext3 allocations, we must not reuse any blocks which are
1245 * allocated in the bitmap buffer's "last committed data" copy.  This
1246 * prevents deletes from freeing up the page for reuse until we have
1247 * committed the delete transaction.
1248 *
1249 * If we didn't do this, then deleting something and reallocating it as
1250 * data would allow the old block to be overwritten before the
1251 * transaction committed (because we force data to disk before commit).
1252 * This would lead to corruption if we crashed between overwriting the
1253 * data and committing the delete.
1254 *
1255 * @@@ We may want to make this allocation behaviour conditional on
1256 * data-writes at some point, and disable it for metadata allocations or
1257 * sync-data inodes."
1258 *
1259 * Note: OCFS2 already does this differently for metadata vs data
1260 * allocations, as those bitmaps are separate and undo access is never
1261 * called on a metadata group descriptor.
1262 */
1263static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
1264					 int nr)
1265{
1266	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 
1267	int ret;
1268
1269	if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
1270		return 0;
1271
1272	if (!buffer_jbd(bg_bh))
 
1273		return 1;
1274
1275	jbd_lock_bh_state(bg_bh);
1276	bg = (struct ocfs2_group_desc *) bh2jh(bg_bh)->b_committed_data;
1277	if (bg)
1278		ret = !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
1279	else
1280		ret = 1;
1281	jbd_unlock_bh_state(bg_bh);
 
1282
1283	return ret;
1284}
1285
1286static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
1287					     struct buffer_head *bg_bh,
1288					     unsigned int bits_wanted,
1289					     unsigned int total_bits,
1290					     struct ocfs2_suballoc_result *res)
1291{
1292	void *bitmap;
1293	u16 best_offset, best_size;
1294	int offset, start, found, status = 0;
1295	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1296
1297	/* Callers got this descriptor from
1298	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1299	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1300
1301	found = start = best_offset = best_size = 0;
1302	bitmap = bg->bg_bitmap;
1303
1304	while((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) != -1) {
1305		if (offset == total_bits)
1306			break;
1307
1308		if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
1309			/* We found a zero, but we can't use it as it
1310			 * hasn't been put to disk yet! */
1311			found = 0;
1312			start = offset + 1;
1313		} else if (offset == start) {
1314			/* we found a zero */
1315			found++;
1316			/* move start to the next bit to test */
1317			start++;
1318		} else {
1319			/* got a zero after some ones */
1320			found = 1;
1321			start = offset + 1;
1322		}
1323		if (found > best_size) {
1324			best_size = found;
1325			best_offset = start - found;
1326		}
1327		/* we got everything we needed */
1328		if (found == bits_wanted) {
1329			/* mlog(0, "Found it all!\n"); */
1330			break;
1331		}
1332	}
1333
1334	if (best_size) {
1335		res->sr_bit_offset = best_offset;
1336		res->sr_bits = best_size;
1337	} else {
1338		status = -ENOSPC;
1339		/* No error log here -- see the comment above
1340		 * ocfs2_test_bg_bit_allocatable */
1341	}
1342
1343	return status;
1344}
1345
1346static inline int ocfs2_block_group_set_bits(handle_t *handle,
1347					     struct inode *alloc_inode,
1348					     struct ocfs2_group_desc *bg,
1349					     struct buffer_head *group_bh,
1350					     unsigned int bit_off,
1351					     unsigned int num_bits)
1352{
1353	int status;
1354	void *bitmap = bg->bg_bitmap;
1355	int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1356
1357	/* All callers get the descriptor via
1358	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1359	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1360	BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
1361
1362	trace_ocfs2_block_group_set_bits(bit_off, num_bits);
1363
1364	if (ocfs2_is_cluster_bitmap(alloc_inode))
1365		journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1366
1367	status = ocfs2_journal_access_gd(handle,
1368					 INODE_CACHE(alloc_inode),
1369					 group_bh,
1370					 journal_type);
1371	if (status < 0) {
1372		mlog_errno(status);
1373		goto bail;
1374	}
1375
1376	le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
1377	if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
1378		ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit"
1379			    " count %u but claims %u are freed. num_bits %d",
1380			    (unsigned long long)le64_to_cpu(bg->bg_blkno),
1381			    le16_to_cpu(bg->bg_bits),
1382			    le16_to_cpu(bg->bg_free_bits_count), num_bits);
1383		return -EROFS;
1384	}
1385	while(num_bits--)
1386		ocfs2_set_bit(bit_off++, bitmap);
1387
1388	ocfs2_journal_dirty(handle, group_bh);
1389
1390bail:
1391	if (status)
1392		mlog_errno(status);
1393	return status;
1394}
1395
1396/* find the one with the most empty bits */
1397static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
1398{
1399	u16 curr, best;
1400
1401	BUG_ON(!cl->cl_next_free_rec);
1402
1403	best = curr = 0;
1404	while (curr < le16_to_cpu(cl->cl_next_free_rec)) {
1405		if (le32_to_cpu(cl->cl_recs[curr].c_free) >
1406		    le32_to_cpu(cl->cl_recs[best].c_free))
1407			best = curr;
1408		curr++;
1409	}
1410
1411	BUG_ON(best >= le16_to_cpu(cl->cl_next_free_rec));
1412	return best;
1413}
1414
1415static int ocfs2_relink_block_group(handle_t *handle,
1416				    struct inode *alloc_inode,
1417				    struct buffer_head *fe_bh,
1418				    struct buffer_head *bg_bh,
1419				    struct buffer_head *prev_bg_bh,
1420				    u16 chain)
1421{
1422	int status;
1423	/* there is a really tiny chance the journal calls could fail,
1424	 * but we wouldn't want inconsistent blocks in *any* case. */
1425	u64 fe_ptr, bg_ptr, prev_bg_ptr;
1426	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
1427	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1428	struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
1429
1430	/* The caller got these descriptors from
1431	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1432	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1433	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(prev_bg));
1434
1435	trace_ocfs2_relink_block_group(
1436		(unsigned long long)le64_to_cpu(fe->i_blkno), chain,
1437		(unsigned long long)le64_to_cpu(bg->bg_blkno),
1438		(unsigned long long)le64_to_cpu(prev_bg->bg_blkno));
1439
1440	fe_ptr = le64_to_cpu(fe->id2.i_chain.cl_recs[chain].c_blkno);
1441	bg_ptr = le64_to_cpu(bg->bg_next_group);
1442	prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
1443
1444	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1445					 prev_bg_bh,
1446					 OCFS2_JOURNAL_ACCESS_WRITE);
1447	if (status < 0) {
1448		mlog_errno(status);
1449		goto out_rollback;
1450	}
1451
1452	prev_bg->bg_next_group = bg->bg_next_group;
1453	ocfs2_journal_dirty(handle, prev_bg_bh);
1454
1455	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1456					 bg_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1457	if (status < 0) {
1458		mlog_errno(status);
1459		goto out_rollback;
1460	}
1461
1462	bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
1463	ocfs2_journal_dirty(handle, bg_bh);
1464
1465	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
1466					 fe_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1467	if (status < 0) {
1468		mlog_errno(status);
1469		goto out_rollback;
1470	}
1471
1472	fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
1473	ocfs2_journal_dirty(handle, fe_bh);
1474
1475out_rollback:
1476	if (status < 0) {
1477		fe->id2.i_chain.cl_recs[chain].c_blkno = cpu_to_le64(fe_ptr);
1478		bg->bg_next_group = cpu_to_le64(bg_ptr);
1479		prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
1480	}
1481
1482	if (status)
1483		mlog_errno(status);
1484	return status;
 
 
 
 
 
 
1485}
1486
1487static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
1488						     u32 wanted)
1489{
1490	return le16_to_cpu(bg->bg_free_bits_count) > wanted;
1491}
1492
1493/* return 0 on success, -ENOSPC to keep searching and any other < 0
1494 * value on error. */
1495static int ocfs2_cluster_group_search(struct inode *inode,
1496				      struct buffer_head *group_bh,
1497				      u32 bits_wanted, u32 min_bits,
1498				      u64 max_block,
1499				      struct ocfs2_suballoc_result *res)
1500{
1501	int search = -ENOSPC;
1502	int ret;
1503	u64 blkoff;
1504	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
1505	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1506	unsigned int max_bits, gd_cluster_off;
1507
1508	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1509
1510	if (gd->bg_free_bits_count) {
1511		max_bits = le16_to_cpu(gd->bg_bits);
1512
1513		/* Tail groups in cluster bitmaps which aren't cpg
1514		 * aligned are prone to partial extension by a failed
1515		 * fs resize. If the file system resize never got to
1516		 * update the dinode cluster count, then we don't want
1517		 * to trust any clusters past it, regardless of what
1518		 * the group descriptor says. */
1519		gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
1520							  le64_to_cpu(gd->bg_blkno));
1521		if ((gd_cluster_off + max_bits) >
1522		    OCFS2_I(inode)->ip_clusters) {
1523			max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
1524			trace_ocfs2_cluster_group_search_wrong_max_bits(
1525				(unsigned long long)le64_to_cpu(gd->bg_blkno),
1526				le16_to_cpu(gd->bg_bits),
1527				OCFS2_I(inode)->ip_clusters, max_bits);
1528		}
1529
1530		ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1531							group_bh, bits_wanted,
1532							max_bits, res);
1533		if (ret)
1534			return ret;
1535
1536		if (max_block) {
1537			blkoff = ocfs2_clusters_to_blocks(inode->i_sb,
1538							  gd_cluster_off +
1539							  res->sr_bit_offset +
1540							  res->sr_bits);
1541			trace_ocfs2_cluster_group_search_max_block(
1542				(unsigned long long)blkoff,
1543				(unsigned long long)max_block);
1544			if (blkoff > max_block)
1545				return -ENOSPC;
1546		}
1547
1548		/* ocfs2_block_group_find_clear_bits() might
1549		 * return success, but we still want to return
1550		 * -ENOSPC unless it found the minimum number
1551		 * of bits. */
1552		if (min_bits <= res->sr_bits)
1553			search = 0; /* success */
1554		else if (res->sr_bits) {
1555			/*
1556			 * Don't show bits which we'll be returning
1557			 * for allocation to the local alloc bitmap.
1558			 */
1559			ocfs2_local_alloc_seen_free_bits(osb, res->sr_bits);
1560		}
1561	}
1562
1563	return search;
1564}
1565
1566static int ocfs2_block_group_search(struct inode *inode,
1567				    struct buffer_head *group_bh,
1568				    u32 bits_wanted, u32 min_bits,
1569				    u64 max_block,
1570				    struct ocfs2_suballoc_result *res)
1571{
1572	int ret = -ENOSPC;
1573	u64 blkoff;
1574	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
1575
1576	BUG_ON(min_bits != 1);
1577	BUG_ON(ocfs2_is_cluster_bitmap(inode));
1578
1579	if (bg->bg_free_bits_count) {
1580		ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1581							group_bh, bits_wanted,
1582							le16_to_cpu(bg->bg_bits),
1583							res);
1584		if (!ret && max_block) {
1585			blkoff = le64_to_cpu(bg->bg_blkno) +
1586				res->sr_bit_offset + res->sr_bits;
1587			trace_ocfs2_block_group_search_max_block(
1588				(unsigned long long)blkoff,
1589				(unsigned long long)max_block);
1590			if (blkoff > max_block)
1591				ret = -ENOSPC;
1592		}
1593	}
1594
1595	return ret;
1596}
1597
1598static int ocfs2_alloc_dinode_update_counts(struct inode *inode,
1599				       handle_t *handle,
1600				       struct buffer_head *di_bh,
1601				       u32 num_bits,
1602				       u16 chain)
1603{
1604	int ret;
1605	u32 tmp_used;
1606	struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1607	struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &di->id2.i_chain;
1608
1609	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
1610				      OCFS2_JOURNAL_ACCESS_WRITE);
1611	if (ret < 0) {
1612		mlog_errno(ret);
1613		goto out;
1614	}
1615
1616	tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1617	di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
1618	le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
1619	ocfs2_journal_dirty(handle, di_bh);
1620
1621out:
1622	return ret;
1623}
1624
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1625static int ocfs2_bg_discontig_fix_by_rec(struct ocfs2_suballoc_result *res,
1626					 struct ocfs2_extent_rec *rec,
1627					 struct ocfs2_chain_list *cl)
1628{
1629	unsigned int bpc = le16_to_cpu(cl->cl_bpc);
1630	unsigned int bitoff = le32_to_cpu(rec->e_cpos) * bpc;
1631	unsigned int bitcount = le16_to_cpu(rec->e_leaf_clusters) * bpc;
1632
1633	if (res->sr_bit_offset < bitoff)
1634		return 0;
1635	if (res->sr_bit_offset >= (bitoff + bitcount))
1636		return 0;
1637	res->sr_blkno = le64_to_cpu(rec->e_blkno) +
1638		(res->sr_bit_offset - bitoff);
1639	if ((res->sr_bit_offset + res->sr_bits) > (bitoff + bitcount))
1640		res->sr_bits = (bitoff + bitcount) - res->sr_bit_offset;
1641	return 1;
1642}
1643
1644static void ocfs2_bg_discontig_fix_result(struct ocfs2_alloc_context *ac,
1645					  struct ocfs2_group_desc *bg,
1646					  struct ocfs2_suballoc_result *res)
1647{
1648	int i;
1649	u64 bg_blkno = res->sr_bg_blkno;  /* Save off */
1650	struct ocfs2_extent_rec *rec;
1651	struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1652	struct ocfs2_chain_list *cl = &di->id2.i_chain;
1653
1654	if (ocfs2_is_cluster_bitmap(ac->ac_inode)) {
1655		res->sr_blkno = 0;
1656		return;
1657	}
1658
1659	res->sr_blkno = res->sr_bg_blkno + res->sr_bit_offset;
1660	res->sr_bg_blkno = 0;  /* Clear it for contig block groups */
1661	if (!ocfs2_supports_discontig_bg(OCFS2_SB(ac->ac_inode->i_sb)) ||
1662	    !bg->bg_list.l_next_free_rec)
1663		return;
1664
1665	for (i = 0; i < le16_to_cpu(bg->bg_list.l_next_free_rec); i++) {
1666		rec = &bg->bg_list.l_recs[i];
1667		if (ocfs2_bg_discontig_fix_by_rec(res, rec, cl)) {
1668			res->sr_bg_blkno = bg_blkno;  /* Restore */
1669			break;
1670		}
1671	}
1672}
1673
1674static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
1675				  handle_t *handle,
1676				  u32 bits_wanted,
1677				  u32 min_bits,
1678				  struct ocfs2_suballoc_result *res,
1679				  u16 *bits_left)
1680{
1681	int ret;
1682	struct buffer_head *group_bh = NULL;
1683	struct ocfs2_group_desc *gd;
1684	struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1685	struct inode *alloc_inode = ac->ac_inode;
1686
1687	ret = ocfs2_read_group_descriptor(alloc_inode, di,
1688					  res->sr_bg_blkno, &group_bh);
1689	if (ret < 0) {
1690		mlog_errno(ret);
1691		return ret;
1692	}
1693
1694	gd = (struct ocfs2_group_desc *) group_bh->b_data;
1695	ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
1696				  ac->ac_max_block, res);
1697	if (ret < 0) {
1698		if (ret != -ENOSPC)
1699			mlog_errno(ret);
1700		goto out;
1701	}
1702
1703	if (!ret)
1704		ocfs2_bg_discontig_fix_result(ac, gd, res);
1705
1706	/*
1707	 * sr_bg_blkno might have been changed by
1708	 * ocfs2_bg_discontig_fix_result
1709	 */
1710	res->sr_bg_stable_blkno = group_bh->b_blocknr;
1711
1712	if (ac->ac_find_loc_only)
1713		goto out_loc_only;
1714
1715	ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
1716					       res->sr_bits,
1717					       le16_to_cpu(gd->bg_chain));
1718	if (ret < 0) {
1719		mlog_errno(ret);
1720		goto out;
1721	}
1722
1723	ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
1724					 res->sr_bit_offset, res->sr_bits);
1725	if (ret < 0)
 
 
 
1726		mlog_errno(ret);
 
1727
1728out_loc_only:
1729	*bits_left = le16_to_cpu(gd->bg_free_bits_count);
1730
1731out:
1732	brelse(group_bh);
1733
1734	return ret;
1735}
1736
1737static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
1738			      handle_t *handle,
1739			      u32 bits_wanted,
1740			      u32 min_bits,
1741			      struct ocfs2_suballoc_result *res,
1742			      u16 *bits_left)
1743{
1744	int status;
1745	u16 chain;
1746	u64 next_group;
1747	struct inode *alloc_inode = ac->ac_inode;
1748	struct buffer_head *group_bh = NULL;
1749	struct buffer_head *prev_group_bh = NULL;
1750	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1751	struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1752	struct ocfs2_group_desc *bg;
1753
1754	chain = ac->ac_chain;
1755	trace_ocfs2_search_chain_begin(
1756		(unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
1757		bits_wanted, chain);
1758
1759	status = ocfs2_read_group_descriptor(alloc_inode, fe,
1760					     le64_to_cpu(cl->cl_recs[chain].c_blkno),
1761					     &group_bh);
1762	if (status < 0) {
1763		mlog_errno(status);
1764		goto bail;
1765	}
1766	bg = (struct ocfs2_group_desc *) group_bh->b_data;
1767
1768	status = -ENOSPC;
1769	/* for now, the chain search is a bit simplistic. We just use
1770	 * the 1st group with any empty bits. */
1771	while ((status = ac->ac_group_search(alloc_inode, group_bh,
1772					     bits_wanted, min_bits,
1773					     ac->ac_max_block,
1774					     res)) == -ENOSPC) {
1775		if (!bg->bg_next_group)
1776			break;
1777
1778		brelse(prev_group_bh);
1779		prev_group_bh = NULL;
1780
1781		next_group = le64_to_cpu(bg->bg_next_group);
1782		prev_group_bh = group_bh;
1783		group_bh = NULL;
1784		status = ocfs2_read_group_descriptor(alloc_inode, fe,
1785						     next_group, &group_bh);
1786		if (status < 0) {
1787			mlog_errno(status);
1788			goto bail;
1789		}
1790		bg = (struct ocfs2_group_desc *) group_bh->b_data;
1791	}
1792	if (status < 0) {
1793		if (status != -ENOSPC)
1794			mlog_errno(status);
1795		goto bail;
1796	}
1797
1798	trace_ocfs2_search_chain_succ(
1799		(unsigned long long)le64_to_cpu(bg->bg_blkno), res->sr_bits);
1800
1801	res->sr_bg_blkno = le64_to_cpu(bg->bg_blkno);
1802
1803	BUG_ON(res->sr_bits == 0);
1804	if (!status)
1805		ocfs2_bg_discontig_fix_result(ac, bg, res);
1806
1807	/*
1808	 * sr_bg_blkno might have been changed by
1809	 * ocfs2_bg_discontig_fix_result
1810	 */
1811	res->sr_bg_stable_blkno = group_bh->b_blocknr;
1812
1813	/*
1814	 * Keep track of previous block descriptor read. When
1815	 * we find a target, if we have read more than X
1816	 * number of descriptors, and the target is reasonably
1817	 * empty, relink him to top of his chain.
1818	 *
1819	 * We've read 0 extra blocks and only send one more to
1820	 * the transaction, yet the next guy to search has a
1821	 * much easier time.
1822	 *
1823	 * Do this *after* figuring out how many bits we're taking out
1824	 * of our target group.
1825	 */
1826	if (ac->ac_allow_chain_relink &&
1827	    (prev_group_bh) &&
1828	    (ocfs2_block_group_reasonably_empty(bg, res->sr_bits))) {
1829		status = ocfs2_relink_block_group(handle, alloc_inode,
1830						  ac->ac_bh, group_bh,
1831						  prev_group_bh, chain);
1832		if (status < 0) {
1833			mlog_errno(status);
1834			goto bail;
1835		}
1836	}
1837
1838	if (ac->ac_find_loc_only)
1839		goto out_loc_only;
1840
1841	status = ocfs2_alloc_dinode_update_counts(alloc_inode, handle,
1842						  ac->ac_bh, res->sr_bits,
1843						  chain);
1844	if (status) {
1845		mlog_errno(status);
1846		goto bail;
1847	}
1848
1849	status = ocfs2_block_group_set_bits(handle,
1850					    alloc_inode,
1851					    bg,
1852					    group_bh,
1853					    res->sr_bit_offset,
1854					    res->sr_bits);
1855	if (status < 0) {
 
 
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		ocfs2_error(ac->ac_inode->i_sb,
1902			    "Chain allocator dinode %llu has %u used "
1903			    "bits but only %u total.",
1904			    (unsigned long long)le64_to_cpu(fe->i_blkno),
1905			    le32_to_cpu(fe->id1.bitmap1.i_used),
1906			    le32_to_cpu(fe->id1.bitmap1.i_total));
1907		status = -EIO;
1908		goto bail;
1909	}
1910
1911	res->sr_bg_blkno = hint;
1912	if (res->sr_bg_blkno) {
1913		/* Attempt to short-circuit the usual search mechanism
1914		 * by jumping straight to the most recently used
1915		 * allocation group. This helps us maintain some
1916		 * contiguousness across allocations. */
1917		status = ocfs2_search_one_group(ac, handle, bits_wanted,
1918						min_bits, res, &bits_left);
1919		if (!status)
1920			goto set_hint;
1921		if (status < 0 && status != -ENOSPC) {
1922			mlog_errno(status);
1923			goto bail;
1924		}
1925	}
1926
1927	cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1928
1929	victim = ocfs2_find_victim_chain(cl);
1930	ac->ac_chain = victim;
1931	ac->ac_allow_chain_relink = 1;
1932
1933	status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1934				    res, &bits_left);
1935	if (!status) {
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_allow_chain_relink = 0;
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
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		mlog_errno(ret);
2169		goto out;
2170	}
2171
2172	trace_ocfs2_claim_new_inode_at_loc((unsigned long long)di_blkno,
2173					   res->sr_bits);
2174
2175	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2176
2177	BUG_ON(res->sr_bits != 1);
2178
2179	*suballoc_loc = res->sr_bg_blkno;
2180	*suballoc_bit = res->sr_bit_offset;
2181	ac->ac_bits_given++;
2182	ocfs2_save_inode_ac_group(dir, ac);
2183
2184out:
2185	brelse(bg_bh);
2186
2187	return ret;
2188}
2189
2190int ocfs2_claim_new_inode(handle_t *handle,
2191			  struct inode *dir,
2192			  struct buffer_head *parent_fe_bh,
2193			  struct ocfs2_alloc_context *ac,
2194			  u64 *suballoc_loc,
2195			  u16 *suballoc_bit,
2196			  u64 *fe_blkno)
2197{
2198	int status;
2199	struct ocfs2_suballoc_result res;
2200
2201	BUG_ON(!ac);
2202	BUG_ON(ac->ac_bits_given != 0);
2203	BUG_ON(ac->ac_bits_wanted != 1);
2204	BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2205
2206	ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2207
2208	status = ocfs2_claim_suballoc_bits(ac,
2209					   handle,
2210					   1,
2211					   1,
2212					   &res);
2213	if (status < 0) {
2214		mlog_errno(status);
2215		goto bail;
2216	}
2217	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2218
2219	BUG_ON(res.sr_bits != 1);
2220
2221	*suballoc_loc = res.sr_bg_blkno;
2222	*suballoc_bit = res.sr_bit_offset;
2223	*fe_blkno = res.sr_blkno;
2224	ac->ac_bits_given++;
2225	ocfs2_save_inode_ac_group(dir, ac);
2226	status = 0;
2227bail:
2228	if (status)
2229		mlog_errno(status);
2230	return status;
2231}
2232
2233/* translate a group desc. blkno and it's bitmap offset into
2234 * disk cluster offset. */
2235static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
2236						   u64 bg_blkno,
2237						   u16 bg_bit_off)
2238{
2239	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2240	u32 cluster = 0;
2241
2242	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2243
2244	if (bg_blkno != osb->first_cluster_group_blkno)
2245		cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
2246	cluster += (u32) bg_bit_off;
2247	return cluster;
2248}
2249
2250/* given a cluster offset, calculate which block group it belongs to
2251 * and return that block offset. */
2252u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster)
2253{
2254	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2255	u32 group_no;
2256
2257	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2258
2259	group_no = cluster / osb->bitmap_cpg;
2260	if (!group_no)
2261		return osb->first_cluster_group_blkno;
2262	return ocfs2_clusters_to_blocks(inode->i_sb,
2263					group_no * osb->bitmap_cpg);
2264}
2265
2266/* given the block number of a cluster start, calculate which cluster
2267 * group and descriptor bitmap offset that corresponds to. */
2268static inline void ocfs2_block_to_cluster_group(struct inode *inode,
2269						u64 data_blkno,
2270						u64 *bg_blkno,
2271						u16 *bg_bit_off)
2272{
2273	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2274	u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
2275
2276	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2277
2278	*bg_blkno = ocfs2_which_cluster_group(inode,
2279					      data_cluster);
2280
2281	if (*bg_blkno == osb->first_cluster_group_blkno)
2282		*bg_bit_off = (u16) data_cluster;
2283	else
2284		*bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
2285							     data_blkno - *bg_blkno);
2286}
2287
2288/*
2289 * min_bits - minimum contiguous chunk from this total allocation we
2290 * can handle. set to what we asked for originally for a full
2291 * contig. allocation, set to '1' to indicate we can deal with extents
2292 * of any size.
2293 */
2294int __ocfs2_claim_clusters(handle_t *handle,
2295			   struct ocfs2_alloc_context *ac,
2296			   u32 min_clusters,
2297			   u32 max_clusters,
2298			   u32 *cluster_start,
2299			   u32 *num_clusters)
2300{
2301	int status;
2302	unsigned int bits_wanted = max_clusters;
2303	struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
2304	struct ocfs2_super *osb = OCFS2_SB(ac->ac_inode->i_sb);
2305
2306	BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
2307
2308	BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
2309	       && ac->ac_which != OCFS2_AC_USE_MAIN);
2310
2311	if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
2312		WARN_ON(min_clusters > 1);
2313
2314		status = ocfs2_claim_local_alloc_bits(osb,
2315						      handle,
2316						      ac,
2317						      bits_wanted,
2318						      cluster_start,
2319						      num_clusters);
2320		if (!status)
2321			atomic_inc(&osb->alloc_stats.local_data);
2322	} else {
2323		if (min_clusters > (osb->bitmap_cpg - 1)) {
2324			/* The only paths asking for contiguousness
2325			 * should know about this already. */
2326			mlog(ML_ERROR, "minimum allocation requested %u exceeds "
2327			     "group bitmap size %u!\n", min_clusters,
2328			     osb->bitmap_cpg);
2329			status = -ENOSPC;
2330			goto bail;
2331		}
2332		/* clamp the current request down to a realistic size. */
2333		if (bits_wanted > (osb->bitmap_cpg - 1))
2334			bits_wanted = osb->bitmap_cpg - 1;
2335
2336		status = ocfs2_claim_suballoc_bits(ac,
2337						   handle,
2338						   bits_wanted,
2339						   min_clusters,
2340						   &res);
2341		if (!status) {
2342			BUG_ON(res.sr_blkno); /* cluster alloc can't set */
2343			*cluster_start =
2344				ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
2345								 res.sr_bg_blkno,
2346								 res.sr_bit_offset);
2347			atomic_inc(&osb->alloc_stats.bitmap_data);
2348			*num_clusters = res.sr_bits;
2349		}
2350	}
2351	if (status < 0) {
2352		if (status != -ENOSPC)
2353			mlog_errno(status);
2354		goto bail;
2355	}
2356
2357	ac->ac_bits_given += *num_clusters;
2358
2359bail:
2360	if (status)
2361		mlog_errno(status);
2362	return status;
2363}
2364
2365int ocfs2_claim_clusters(handle_t *handle,
2366			 struct ocfs2_alloc_context *ac,
2367			 u32 min_clusters,
2368			 u32 *cluster_start,
2369			 u32 *num_clusters)
2370{
2371	unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
2372
2373	return __ocfs2_claim_clusters(handle, ac, min_clusters,
2374				      bits_wanted, cluster_start, num_clusters);
2375}
2376
2377static int ocfs2_block_group_clear_bits(handle_t *handle,
2378					struct inode *alloc_inode,
2379					struct ocfs2_group_desc *bg,
2380					struct buffer_head *group_bh,
2381					unsigned int bit_off,
2382					unsigned int num_bits,
2383					void (*undo_fn)(unsigned int bit,
2384							unsigned long *bmap))
2385{
2386	int status;
2387	unsigned int tmp;
2388	struct ocfs2_group_desc *undo_bg = NULL;
 
2389
2390	/* The caller got this descriptor from
2391	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
2392	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
2393
2394	trace_ocfs2_block_group_clear_bits(bit_off, num_bits);
2395
2396	BUG_ON(undo_fn && !ocfs2_is_cluster_bitmap(alloc_inode));
2397	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
2398					 group_bh,
2399					 undo_fn ?
2400					 OCFS2_JOURNAL_ACCESS_UNDO :
2401					 OCFS2_JOURNAL_ACCESS_WRITE);
2402	if (status < 0) {
2403		mlog_errno(status);
2404		goto bail;
2405	}
2406
 
2407	if (undo_fn) {
2408		jbd_lock_bh_state(group_bh);
2409		undo_bg = (struct ocfs2_group_desc *)
2410					bh2jh(group_bh)->b_committed_data;
2411		BUG_ON(!undo_bg);
2412	}
2413
2414	tmp = num_bits;
2415	while(tmp--) {
2416		ocfs2_clear_bit((bit_off + tmp),
2417				(unsigned long *) bg->bg_bitmap);
2418		if (undo_fn)
2419			undo_fn(bit_off + tmp,
2420				(unsigned long *) undo_bg->bg_bitmap);
2421	}
2422	le16_add_cpu(&bg->bg_free_bits_count, num_bits);
2423	if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
2424		ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit"
2425			    " count %u but claims %u are freed. num_bits %d",
2426			    (unsigned long long)le64_to_cpu(bg->bg_blkno),
2427			    le16_to_cpu(bg->bg_bits),
2428			    le16_to_cpu(bg->bg_free_bits_count), num_bits);
2429		return -EROFS;
 
2430	}
2431
2432	if (undo_fn)
2433		jbd_unlock_bh_state(group_bh);
2434
2435	ocfs2_journal_dirty(handle, group_bh);
2436bail:
2437	return status;
2438}
2439
2440/*
2441 * expects the suballoc inode to already be locked.
2442 */
2443static int _ocfs2_free_suballoc_bits(handle_t *handle,
2444				     struct inode *alloc_inode,
2445				     struct buffer_head *alloc_bh,
2446				     unsigned int start_bit,
2447				     u64 bg_blkno,
2448				     unsigned int count,
2449				     void (*undo_fn)(unsigned int bit,
2450						     unsigned long *bitmap))
2451{
2452	int status = 0;
2453	u32 tmp_used;
2454	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
2455	struct ocfs2_chain_list *cl = &fe->id2.i_chain;
2456	struct buffer_head *group_bh = NULL;
2457	struct ocfs2_group_desc *group;
2458
2459	/* The alloc_bh comes from ocfs2_free_dinode() or
2460	 * ocfs2_free_clusters().  The callers have all locked the
2461	 * allocator and gotten alloc_bh from the lock call.  This
2462	 * validates the dinode buffer.  Any corruption that has happened
2463	 * is a code bug. */
2464	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
2465	BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
2466
2467	trace_ocfs2_free_suballoc_bits(
2468		(unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
2469		(unsigned long long)bg_blkno,
2470		start_bit, count);
2471
2472	status = ocfs2_read_group_descriptor(alloc_inode, fe, bg_blkno,
2473					     &group_bh);
2474	if (status < 0) {
2475		mlog_errno(status);
2476		goto bail;
2477	}
2478	group = (struct ocfs2_group_desc *) group_bh->b_data;
2479
2480	BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
2481
2482	status = ocfs2_block_group_clear_bits(handle, alloc_inode,
2483					      group, group_bh,
2484					      start_bit, count, undo_fn);
2485	if (status < 0) {
2486		mlog_errno(status);
2487		goto bail;
2488	}
2489
2490	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
2491					 alloc_bh, OCFS2_JOURNAL_ACCESS_WRITE);
2492	if (status < 0) {
2493		mlog_errno(status);
 
 
2494		goto bail;
2495	}
2496
2497	le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
2498		     count);
2499	tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
2500	fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
2501	ocfs2_journal_dirty(handle, alloc_bh);
2502
2503bail:
2504	brelse(group_bh);
2505
2506	if (status)
2507		mlog_errno(status);
2508	return status;
2509}
2510
2511int ocfs2_free_suballoc_bits(handle_t *handle,
2512			     struct inode *alloc_inode,
2513			     struct buffer_head *alloc_bh,
2514			     unsigned int start_bit,
2515			     u64 bg_blkno,
2516			     unsigned int count)
2517{
2518	return _ocfs2_free_suballoc_bits(handle, alloc_inode, alloc_bh,
2519					 start_bit, bg_blkno, count, NULL);
2520}
2521
2522int ocfs2_free_dinode(handle_t *handle,
2523		      struct inode *inode_alloc_inode,
2524		      struct buffer_head *inode_alloc_bh,
2525		      struct ocfs2_dinode *di)
2526{
2527	u64 blk = le64_to_cpu(di->i_blkno);
2528	u16 bit = le16_to_cpu(di->i_suballoc_bit);
2529	u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
2530
2531	if (di->i_suballoc_loc)
2532		bg_blkno = le64_to_cpu(di->i_suballoc_loc);
2533	return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
2534					inode_alloc_bh, bit, bg_blkno, 1);
2535}
2536
2537static int _ocfs2_free_clusters(handle_t *handle,
2538				struct inode *bitmap_inode,
2539				struct buffer_head *bitmap_bh,
2540				u64 start_blk,
2541				unsigned int num_clusters,
2542				void (*undo_fn)(unsigned int bit,
2543						unsigned long *bitmap))
2544{
2545	int status;
2546	u16 bg_start_bit;
2547	u64 bg_blkno;
2548	struct ocfs2_dinode *fe;
2549
2550	/* You can't ever have a contiguous set of clusters
2551	 * bigger than a block group bitmap so we never have to worry
2552	 * about looping on them.
2553	 * This is expensive. We can safely remove once this stuff has
2554	 * gotten tested really well. */
2555	BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb, ocfs2_blocks_to_clusters(bitmap_inode->i_sb, start_blk)));
 
 
2556
2557	fe = (struct ocfs2_dinode *) bitmap_bh->b_data;
2558
2559	ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
2560				     &bg_start_bit);
2561
2562	trace_ocfs2_free_clusters((unsigned long long)bg_blkno,
2563			(unsigned long long)start_blk,
2564			bg_start_bit, num_clusters);
2565
2566	status = _ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
2567					   bg_start_bit, bg_blkno,
2568					   num_clusters, undo_fn);
2569	if (status < 0) {
2570		mlog_errno(status);
2571		goto out;
2572	}
2573
2574	ocfs2_local_alloc_seen_free_bits(OCFS2_SB(bitmap_inode->i_sb),
2575					 num_clusters);
2576
2577out:
2578	if (status)
2579		mlog_errno(status);
2580	return status;
2581}
2582
2583int ocfs2_free_clusters(handle_t *handle,
2584			struct inode *bitmap_inode,
2585			struct buffer_head *bitmap_bh,
2586			u64 start_blk,
2587			unsigned int num_clusters)
2588{
2589	return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2590				    start_blk, num_clusters,
2591				    _ocfs2_set_bit);
2592}
2593
2594/*
2595 * Give never-used clusters back to the global bitmap.  We don't need
2596 * to protect these bits in the undo buffer.
2597 */
2598int ocfs2_release_clusters(handle_t *handle,
2599			   struct inode *bitmap_inode,
2600			   struct buffer_head *bitmap_bh,
2601			   u64 start_blk,
2602			   unsigned int num_clusters)
2603{
2604	return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2605				    start_blk, num_clusters,
2606				    _ocfs2_clear_bit);
2607}
2608
2609static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg)
2610{
2611	printk("Block Group:\n");
2612	printk("bg_signature:       %s\n", bg->bg_signature);
2613	printk("bg_size:            %u\n", bg->bg_size);
2614	printk("bg_bits:            %u\n", bg->bg_bits);
2615	printk("bg_free_bits_count: %u\n", bg->bg_free_bits_count);
2616	printk("bg_chain:           %u\n", bg->bg_chain);
2617	printk("bg_generation:      %u\n", le32_to_cpu(bg->bg_generation));
2618	printk("bg_next_group:      %llu\n",
2619	       (unsigned long long)bg->bg_next_group);
2620	printk("bg_parent_dinode:   %llu\n",
2621	       (unsigned long long)bg->bg_parent_dinode);
2622	printk("bg_blkno:           %llu\n",
2623	       (unsigned long long)bg->bg_blkno);
2624}
2625
2626static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe)
2627{
2628	int i;
2629
2630	printk("Suballoc Inode %llu:\n", (unsigned long long)fe->i_blkno);
2631	printk("i_signature:                  %s\n", fe->i_signature);
2632	printk("i_size:                       %llu\n",
2633	       (unsigned long long)fe->i_size);
2634	printk("i_clusters:                   %u\n", fe->i_clusters);
2635	printk("i_generation:                 %u\n",
2636	       le32_to_cpu(fe->i_generation));
2637	printk("id1.bitmap1.i_used:           %u\n",
2638	       le32_to_cpu(fe->id1.bitmap1.i_used));
2639	printk("id1.bitmap1.i_total:          %u\n",
2640	       le32_to_cpu(fe->id1.bitmap1.i_total));
2641	printk("id2.i_chain.cl_cpg:           %u\n", fe->id2.i_chain.cl_cpg);
2642	printk("id2.i_chain.cl_bpc:           %u\n", fe->id2.i_chain.cl_bpc);
2643	printk("id2.i_chain.cl_count:         %u\n", fe->id2.i_chain.cl_count);
2644	printk("id2.i_chain.cl_next_free_rec: %u\n",
2645	       fe->id2.i_chain.cl_next_free_rec);
2646	for(i = 0; i < fe->id2.i_chain.cl_next_free_rec; i++) {
2647		printk("fe->id2.i_chain.cl_recs[%d].c_free:  %u\n", i,
2648		       fe->id2.i_chain.cl_recs[i].c_free);
2649		printk("fe->id2.i_chain.cl_recs[%d].c_total: %u\n", i,
2650		       fe->id2.i_chain.cl_recs[i].c_total);
2651		printk("fe->id2.i_chain.cl_recs[%d].c_blkno: %llu\n", i,
2652		       (unsigned long long)fe->id2.i_chain.cl_recs[i].c_blkno);
2653	}
2654}
2655
2656/*
2657 * For a given allocation, determine which allocators will need to be
2658 * accessed, and lock them, reserving the appropriate number of bits.
2659 *
2660 * Sparse file systems call this from ocfs2_write_begin_nolock()
2661 * and ocfs2_allocate_unwritten_extents().
2662 *
2663 * File systems which don't support holes call this from
2664 * ocfs2_extend_allocation().
2665 */
2666int ocfs2_lock_allocators(struct inode *inode,
2667			  struct ocfs2_extent_tree *et,
2668			  u32 clusters_to_add, u32 extents_to_split,
2669			  struct ocfs2_alloc_context **data_ac,
2670			  struct ocfs2_alloc_context **meta_ac)
2671{
2672	int ret = 0, num_free_extents;
2673	unsigned int max_recs_needed = clusters_to_add + 2 * extents_to_split;
2674	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2675
2676	*meta_ac = NULL;
2677	if (data_ac)
2678		*data_ac = NULL;
2679
2680	BUG_ON(clusters_to_add != 0 && data_ac == NULL);
2681
2682	num_free_extents = ocfs2_num_free_extents(osb, et);
2683	if (num_free_extents < 0) {
2684		ret = num_free_extents;
2685		mlog_errno(ret);
2686		goto out;
2687	}
2688
2689	/*
2690	 * Sparse allocation file systems need to be more conservative
2691	 * with reserving room for expansion - the actual allocation
2692	 * happens while we've got a journal handle open so re-taking
2693	 * a cluster lock (because we ran out of room for another
2694	 * extent) will violate ordering rules.
2695	 *
2696	 * Most of the time we'll only be seeing this 1 cluster at a time
2697	 * anyway.
2698	 *
2699	 * Always lock for any unwritten extents - we might want to
2700	 * add blocks during a split.
2701	 */
2702	if (!num_free_extents ||
2703	    (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed)) {
2704		ret = ocfs2_reserve_new_metadata(osb, et->et_root_el, meta_ac);
2705		if (ret < 0) {
2706			if (ret != -ENOSPC)
2707				mlog_errno(ret);
2708			goto out;
2709		}
2710	}
2711
2712	if (clusters_to_add == 0)
2713		goto out;
2714
2715	ret = ocfs2_reserve_clusters(osb, clusters_to_add, data_ac);
2716	if (ret < 0) {
2717		if (ret != -ENOSPC)
2718			mlog_errno(ret);
2719		goto out;
2720	}
2721
2722out:
2723	if (ret) {
2724		if (*meta_ac) {
2725			ocfs2_free_alloc_context(*meta_ac);
2726			*meta_ac = NULL;
2727		}
2728
2729		/*
2730		 * We cannot have an error and a non null *data_ac.
2731		 */
2732	}
2733
2734	return ret;
2735}
2736
2737/*
2738 * Read the inode specified by blkno to get suballoc_slot and
2739 * suballoc_bit.
2740 */
2741static int ocfs2_get_suballoc_slot_bit(struct ocfs2_super *osb, u64 blkno,
2742				       u16 *suballoc_slot, u64 *group_blkno,
2743				       u16 *suballoc_bit)
2744{
2745	int status;
2746	struct buffer_head *inode_bh = NULL;
2747	struct ocfs2_dinode *inode_fe;
2748
2749	trace_ocfs2_get_suballoc_slot_bit((unsigned long long)blkno);
2750
2751	/* dirty read disk */
2752	status = ocfs2_read_blocks_sync(osb, blkno, 1, &inode_bh);
2753	if (status < 0) {
2754		mlog(ML_ERROR, "read block %llu failed %d\n",
2755		     (unsigned long long)blkno, status);
2756		goto bail;
2757	}
2758
2759	inode_fe = (struct ocfs2_dinode *) inode_bh->b_data;
2760	if (!OCFS2_IS_VALID_DINODE(inode_fe)) {
2761		mlog(ML_ERROR, "invalid inode %llu requested\n",
2762		     (unsigned long long)blkno);
2763		status = -EINVAL;
2764		goto bail;
2765	}
2766
2767	if (le16_to_cpu(inode_fe->i_suballoc_slot) != (u16)OCFS2_INVALID_SLOT &&
2768	    (u32)le16_to_cpu(inode_fe->i_suballoc_slot) > osb->max_slots - 1) {
2769		mlog(ML_ERROR, "inode %llu has invalid suballoc slot %u\n",
2770		     (unsigned long long)blkno,
2771		     (u32)le16_to_cpu(inode_fe->i_suballoc_slot));
2772		status = -EINVAL;
2773		goto bail;
2774	}
2775
2776	if (suballoc_slot)
2777		*suballoc_slot = le16_to_cpu(inode_fe->i_suballoc_slot);
2778	if (suballoc_bit)
2779		*suballoc_bit = le16_to_cpu(inode_fe->i_suballoc_bit);
2780	if (group_blkno)
2781		*group_blkno = le64_to_cpu(inode_fe->i_suballoc_loc);
2782
2783bail:
2784	brelse(inode_bh);
2785
2786	if (status)
2787		mlog_errno(status);
2788	return status;
2789}
2790
2791/*
2792 * test whether bit is SET in allocator bitmap or not.  on success, 0
2793 * is returned and *res is 1 for SET; 0 otherwise.  when fails, errno
2794 * is returned and *res is meaningless.  Call this after you have
2795 * cluster locked against suballoc, or you may get a result based on
2796 * non-up2date contents
2797 */
2798static int ocfs2_test_suballoc_bit(struct ocfs2_super *osb,
2799				   struct inode *suballoc,
2800				   struct buffer_head *alloc_bh,
2801				   u64 group_blkno, u64 blkno,
2802				   u16 bit, int *res)
2803{
2804	struct ocfs2_dinode *alloc_di;
2805	struct ocfs2_group_desc *group;
2806	struct buffer_head *group_bh = NULL;
2807	u64 bg_blkno;
2808	int status;
2809
2810	trace_ocfs2_test_suballoc_bit((unsigned long long)blkno,
2811				      (unsigned int)bit);
2812
2813	alloc_di = (struct ocfs2_dinode *)alloc_bh->b_data;
2814	if ((bit + 1) > ocfs2_bits_per_group(&alloc_di->id2.i_chain)) {
2815		mlog(ML_ERROR, "suballoc bit %u out of range of %u\n",
2816		     (unsigned int)bit,
2817		     ocfs2_bits_per_group(&alloc_di->id2.i_chain));
2818		status = -EINVAL;
2819		goto bail;
2820	}
2821
2822	bg_blkno = group_blkno ? group_blkno :
2823		   ocfs2_which_suballoc_group(blkno, bit);
2824	status = ocfs2_read_group_descriptor(suballoc, alloc_di, bg_blkno,
2825					     &group_bh);
2826	if (status < 0) {
2827		mlog(ML_ERROR, "read group %llu failed %d\n",
2828		     (unsigned long long)bg_blkno, status);
2829		goto bail;
2830	}
2831
2832	group = (struct ocfs2_group_desc *) group_bh->b_data;
2833	*res = ocfs2_test_bit(bit, (unsigned long *)group->bg_bitmap);
2834
2835bail:
2836	brelse(group_bh);
2837
2838	if (status)
2839		mlog_errno(status);
2840	return status;
2841}
2842
2843/*
2844 * Test if the bit representing this inode (blkno) is set in the
2845 * suballocator.
2846 *
2847 * On success, 0 is returned and *res is 1 for SET; 0 otherwise.
2848 *
2849 * In the event of failure, a negative value is returned and *res is
2850 * meaningless.
2851 *
2852 * Callers must make sure to hold nfs_sync_lock to prevent
2853 * ocfs2_delete_inode() on another node from accessing the same
2854 * suballocator concurrently.
2855 */
2856int ocfs2_test_inode_bit(struct ocfs2_super *osb, u64 blkno, int *res)
2857{
2858	int status;
2859	u64 group_blkno = 0;
2860	u16 suballoc_bit = 0, suballoc_slot = 0;
2861	struct inode *inode_alloc_inode;
2862	struct buffer_head *alloc_bh = NULL;
2863
2864	trace_ocfs2_test_inode_bit((unsigned long long)blkno);
2865
2866	status = ocfs2_get_suballoc_slot_bit(osb, blkno, &suballoc_slot,
2867					     &group_blkno, &suballoc_bit);
2868	if (status < 0) {
2869		mlog(ML_ERROR, "get alloc slot and bit failed %d\n", status);
2870		goto bail;
2871	}
2872
2873	inode_alloc_inode =
2874		ocfs2_get_system_file_inode(osb, INODE_ALLOC_SYSTEM_INODE,
2875					    suballoc_slot);
 
 
 
2876	if (!inode_alloc_inode) {
2877		/* the error code could be inaccurate, but we are not able to
2878		 * get the correct one. */
2879		status = -EINVAL;
2880		mlog(ML_ERROR, "unable to get alloc inode in slot %u\n",
2881		     (u32)suballoc_slot);
2882		goto bail;
2883	}
2884
2885	mutex_lock(&inode_alloc_inode->i_mutex);
2886	status = ocfs2_inode_lock(inode_alloc_inode, &alloc_bh, 0);
2887	if (status < 0) {
2888		mutex_unlock(&inode_alloc_inode->i_mutex);
 
2889		mlog(ML_ERROR, "lock on alloc inode on slot %u failed %d\n",
2890		     (u32)suballoc_slot, status);
2891		goto bail;
2892	}
2893
2894	status = ocfs2_test_suballoc_bit(osb, inode_alloc_inode, alloc_bh,
2895					 group_blkno, blkno, suballoc_bit, res);
2896	if (status < 0)
2897		mlog(ML_ERROR, "test suballoc bit failed %d\n", status);
2898
2899	ocfs2_inode_unlock(inode_alloc_inode, 0);
2900	mutex_unlock(&inode_alloc_inode->i_mutex);
2901
2902	iput(inode_alloc_inode);
2903	brelse(alloc_bh);
2904bail:
2905	if (status)
2906		mlog_errno(status);
2907	return status;
2908}