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v3.15
   1/* -*- mode: c; c-basic-offset: 8; -*-
   2 * vim: noexpandtab sw=8 ts=8 sts=0:
   3 *
   4 * suballoc.c
   5 *
   6 * metadata alloc and free
   7 * Inspired by ext3 block groups.
   8 *
   9 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
  10 *
  11 * This program is free software; you can redistribute it and/or
  12 * modify it under the terms of the GNU General Public
  13 * License as published by the Free Software Foundation; either
  14 * version 2 of the License, or (at your option) any later version.
  15 *
  16 * This program is distributed in the hope that it will be useful,
  17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19 * General Public License for more details.
  20 *
  21 * You should have received a copy of the GNU General Public
  22 * License along with this program; if not, write to the
  23 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  24 * Boston, MA 021110-1307, USA.
  25 */
  26
  27#include <linux/fs.h>
  28#include <linux/types.h>
  29#include <linux/slab.h>
  30#include <linux/highmem.h>
  31
  32#include <cluster/masklog.h>
  33
  34#include "ocfs2.h"
  35
  36#include "alloc.h"
  37#include "blockcheck.h"
  38#include "dlmglue.h"
  39#include "inode.h"
  40#include "journal.h"
  41#include "localalloc.h"
  42#include "suballoc.h"
  43#include "super.h"
  44#include "sysfile.h"
  45#include "uptodate.h"
  46#include "ocfs2_trace.h"
  47
  48#include "buffer_head_io.h"
  49
  50#define NOT_ALLOC_NEW_GROUP		0
  51#define ALLOC_NEW_GROUP			0x1
  52#define ALLOC_GROUPS_FROM_GLOBAL	0x2
  53
  54#define OCFS2_MAX_TO_STEAL		1024
  55
  56struct ocfs2_suballoc_result {
  57	u64		sr_bg_blkno;	/* The bg we allocated from.  Set
  58					   to 0 when a block group is
  59					   contiguous. */
  60	u64		sr_bg_stable_blkno; /*
  61					     * Doesn't change, always
  62					     * set to target block
  63					     * group descriptor
  64					     * block.
  65					     */
  66	u64		sr_blkno;	/* The first allocated block */
  67	unsigned int	sr_bit_offset;	/* The bit in the bg */
  68	unsigned int	sr_bits;	/* How many bits we claimed */
  69};
  70
  71static u64 ocfs2_group_from_res(struct ocfs2_suballoc_result *res)
  72{
  73	if (res->sr_blkno == 0)
  74		return 0;
  75
  76	if (res->sr_bg_blkno)
  77		return res->sr_bg_blkno;
  78
  79	return ocfs2_which_suballoc_group(res->sr_blkno, res->sr_bit_offset);
  80}
  81
  82static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg);
  83static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe);
  84static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl);
  85static int ocfs2_block_group_fill(handle_t *handle,
  86				  struct inode *alloc_inode,
  87				  struct buffer_head *bg_bh,
  88				  u64 group_blkno,
  89				  unsigned int group_clusters,
  90				  u16 my_chain,
  91				  struct ocfs2_chain_list *cl);
  92static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
  93				   struct inode *alloc_inode,
  94				   struct buffer_head *bh,
  95				   u64 max_block,
  96				   u64 *last_alloc_group,
  97				   int flags);
  98
  99static int ocfs2_cluster_group_search(struct inode *inode,
 100				      struct buffer_head *group_bh,
 101				      u32 bits_wanted, u32 min_bits,
 102				      u64 max_block,
 103				      struct ocfs2_suballoc_result *res);
 104static int ocfs2_block_group_search(struct inode *inode,
 105				    struct buffer_head *group_bh,
 106				    u32 bits_wanted, u32 min_bits,
 107				    u64 max_block,
 108				    struct ocfs2_suballoc_result *res);
 109static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
 110				     handle_t *handle,
 111				     u32 bits_wanted,
 112				     u32 min_bits,
 113				     struct ocfs2_suballoc_result *res);
 114static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
 115					 int nr);
 116static int ocfs2_relink_block_group(handle_t *handle,
 117				    struct inode *alloc_inode,
 118				    struct buffer_head *fe_bh,
 119				    struct buffer_head *bg_bh,
 120				    struct buffer_head *prev_bg_bh,
 121				    u16 chain);
 122static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
 123						     u32 wanted);
 124static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
 125						   u64 bg_blkno,
 126						   u16 bg_bit_off);
 127static inline void ocfs2_block_to_cluster_group(struct inode *inode,
 128						u64 data_blkno,
 129						u64 *bg_blkno,
 130						u16 *bg_bit_off);
 131static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
 132					     u32 bits_wanted, u64 max_block,
 133					     int flags,
 134					     struct ocfs2_alloc_context **ac);
 135
 136void ocfs2_free_ac_resource(struct ocfs2_alloc_context *ac)
 137{
 138	struct inode *inode = ac->ac_inode;
 139
 140	if (inode) {
 141		if (ac->ac_which != OCFS2_AC_USE_LOCAL)
 142			ocfs2_inode_unlock(inode, 1);
 143
 144		mutex_unlock(&inode->i_mutex);
 145
 146		iput(inode);
 147		ac->ac_inode = NULL;
 148	}
 149	brelse(ac->ac_bh);
 150	ac->ac_bh = NULL;
 151	ac->ac_resv = NULL;
 152	if (ac->ac_find_loc_priv) {
 153		kfree(ac->ac_find_loc_priv);
 154		ac->ac_find_loc_priv = NULL;
 155	}
 156}
 157
 158void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
 159{
 160	ocfs2_free_ac_resource(ac);
 161	kfree(ac);
 162}
 163
 164static u32 ocfs2_bits_per_group(struct ocfs2_chain_list *cl)
 165{
 166	return (u32)le16_to_cpu(cl->cl_cpg) * (u32)le16_to_cpu(cl->cl_bpc);
 167}
 168
 169#define do_error(fmt, ...)						\
 170	do{								\
 171		if (resize)					\
 172			mlog(ML_ERROR, fmt "\n", ##__VA_ARGS__);	\
 173		else							\
 174			ocfs2_error(sb, fmt, ##__VA_ARGS__);		\
 175	} while (0)
 176
 177static int ocfs2_validate_gd_self(struct super_block *sb,
 178				  struct buffer_head *bh,
 179				  int resize)
 180{
 181	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 182
 183	if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
 184		do_error("Group descriptor #%llu has bad signature %.*s",
 185			 (unsigned long long)bh->b_blocknr, 7,
 186			 gd->bg_signature);
 187		return -EINVAL;
 188	}
 189
 190	if (le64_to_cpu(gd->bg_blkno) != bh->b_blocknr) {
 191		do_error("Group descriptor #%llu has an invalid bg_blkno "
 192			 "of %llu",
 193			 (unsigned long long)bh->b_blocknr,
 194			 (unsigned long long)le64_to_cpu(gd->bg_blkno));
 195		return -EINVAL;
 196	}
 197
 198	if (le32_to_cpu(gd->bg_generation) != OCFS2_SB(sb)->fs_generation) {
 199		do_error("Group descriptor #%llu has an invalid "
 200			 "fs_generation of #%u",
 201			 (unsigned long long)bh->b_blocknr,
 202			 le32_to_cpu(gd->bg_generation));
 203		return -EINVAL;
 204	}
 205
 206	if (le16_to_cpu(gd->bg_free_bits_count) > le16_to_cpu(gd->bg_bits)) {
 207		do_error("Group descriptor #%llu has bit count %u but "
 208			 "claims that %u are free",
 209			 (unsigned long long)bh->b_blocknr,
 210			 le16_to_cpu(gd->bg_bits),
 211			 le16_to_cpu(gd->bg_free_bits_count));
 212		return -EINVAL;
 213	}
 214
 215	if (le16_to_cpu(gd->bg_bits) > (8 * le16_to_cpu(gd->bg_size))) {
 216		do_error("Group descriptor #%llu has bit count %u but "
 217			 "max bitmap bits of %u",
 218			 (unsigned long long)bh->b_blocknr,
 219			 le16_to_cpu(gd->bg_bits),
 220			 8 * le16_to_cpu(gd->bg_size));
 221		return -EINVAL;
 222	}
 223
 224	return 0;
 225}
 226
 227static int ocfs2_validate_gd_parent(struct super_block *sb,
 228				    struct ocfs2_dinode *di,
 229				    struct buffer_head *bh,
 230				    int resize)
 231{
 232	unsigned int max_bits;
 233	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 234
 235	if (di->i_blkno != gd->bg_parent_dinode) {
 236		do_error("Group descriptor #%llu has bad parent "
 237			 "pointer (%llu, expected %llu)",
 238			 (unsigned long long)bh->b_blocknr,
 239			 (unsigned long long)le64_to_cpu(gd->bg_parent_dinode),
 240			 (unsigned long long)le64_to_cpu(di->i_blkno));
 241		return -EINVAL;
 242	}
 243
 244	max_bits = le16_to_cpu(di->id2.i_chain.cl_cpg) * le16_to_cpu(di->id2.i_chain.cl_bpc);
 245	if (le16_to_cpu(gd->bg_bits) > max_bits) {
 246		do_error("Group descriptor #%llu has bit count of %u",
 247			 (unsigned long long)bh->b_blocknr,
 248			 le16_to_cpu(gd->bg_bits));
 249		return -EINVAL;
 250	}
 251
 252	/* In resize, we may meet the case bg_chain == cl_next_free_rec. */
 253	if ((le16_to_cpu(gd->bg_chain) >
 254	     le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) ||
 255	    ((le16_to_cpu(gd->bg_chain) ==
 256	     le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) && !resize)) {
 257		do_error("Group descriptor #%llu has bad chain %u",
 258			 (unsigned long long)bh->b_blocknr,
 259			 le16_to_cpu(gd->bg_chain));
 260		return -EINVAL;
 261	}
 262
 263	return 0;
 264}
 265
 266#undef do_error
 267
 268/*
 269 * This version only prints errors.  It does not fail the filesystem, and
 270 * exists only for resize.
 271 */
 272int ocfs2_check_group_descriptor(struct super_block *sb,
 273				 struct ocfs2_dinode *di,
 274				 struct buffer_head *bh)
 275{
 276	int rc;
 277	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 278
 279	BUG_ON(!buffer_uptodate(bh));
 280
 281	/*
 282	 * If the ecc fails, we return the error but otherwise
 283	 * leave the filesystem running.  We know any error is
 284	 * local to this block.
 285	 */
 286	rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
 287	if (rc) {
 288		mlog(ML_ERROR,
 289		     "Checksum failed for group descriptor %llu\n",
 290		     (unsigned long long)bh->b_blocknr);
 291	} else
 292		rc = ocfs2_validate_gd_self(sb, bh, 1);
 293	if (!rc)
 294		rc = ocfs2_validate_gd_parent(sb, di, bh, 1);
 295
 296	return rc;
 297}
 298
 299static int ocfs2_validate_group_descriptor(struct super_block *sb,
 300					   struct buffer_head *bh)
 301{
 302	int rc;
 303	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 304
 305	trace_ocfs2_validate_group_descriptor(
 306					(unsigned long long)bh->b_blocknr);
 307
 308	BUG_ON(!buffer_uptodate(bh));
 309
 310	/*
 311	 * If the ecc fails, we return the error but otherwise
 312	 * leave the filesystem running.  We know any error is
 313	 * local to this block.
 314	 */
 315	rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
 316	if (rc)
 317		return rc;
 318
 319	/*
 320	 * Errors after here are fatal.
 321	 */
 322
 323	return ocfs2_validate_gd_self(sb, bh, 0);
 324}
 325
 326int ocfs2_read_group_descriptor(struct inode *inode, struct ocfs2_dinode *di,
 327				u64 gd_blkno, struct buffer_head **bh)
 328{
 329	int rc;
 330	struct buffer_head *tmp = *bh;
 331
 332	rc = ocfs2_read_block(INODE_CACHE(inode), gd_blkno, &tmp,
 333			      ocfs2_validate_group_descriptor);
 334	if (rc)
 335		goto out;
 336
 337	rc = ocfs2_validate_gd_parent(inode->i_sb, di, tmp, 0);
 338	if (rc) {
 339		brelse(tmp);
 340		goto out;
 341	}
 342
 343	/* If ocfs2_read_block() got us a new bh, pass it up. */
 344	if (!*bh)
 345		*bh = tmp;
 346
 347out:
 348	return rc;
 349}
 350
 351static void ocfs2_bg_discontig_add_extent(struct ocfs2_super *osb,
 352					  struct ocfs2_group_desc *bg,
 353					  struct ocfs2_chain_list *cl,
 354					  u64 p_blkno, unsigned int clusters)
 355{
 356	struct ocfs2_extent_list *el = &bg->bg_list;
 357	struct ocfs2_extent_rec *rec;
 358
 359	BUG_ON(!ocfs2_supports_discontig_bg(osb));
 360	if (!el->l_next_free_rec)
 361		el->l_count = cpu_to_le16(ocfs2_extent_recs_per_gd(osb->sb));
 362	rec = &el->l_recs[le16_to_cpu(el->l_next_free_rec)];
 363	rec->e_blkno = cpu_to_le64(p_blkno);
 364	rec->e_cpos = cpu_to_le32(le16_to_cpu(bg->bg_bits) /
 365				  le16_to_cpu(cl->cl_bpc));
 366	rec->e_leaf_clusters = cpu_to_le16(clusters);
 367	le16_add_cpu(&bg->bg_bits, clusters * le16_to_cpu(cl->cl_bpc));
 368	le16_add_cpu(&bg->bg_free_bits_count,
 369		     clusters * le16_to_cpu(cl->cl_bpc));
 370	le16_add_cpu(&el->l_next_free_rec, 1);
 371}
 372
 373static int ocfs2_block_group_fill(handle_t *handle,
 374				  struct inode *alloc_inode,
 375				  struct buffer_head *bg_bh,
 376				  u64 group_blkno,
 377				  unsigned int group_clusters,
 378				  u16 my_chain,
 379				  struct ocfs2_chain_list *cl)
 380{
 381	int status = 0;
 382	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 383	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 384	struct super_block * sb = alloc_inode->i_sb;
 385
 386	if (((unsigned long long) bg_bh->b_blocknr) != group_blkno) {
 387		ocfs2_error(alloc_inode->i_sb, "group block (%llu) != "
 388			    "b_blocknr (%llu)",
 389			    (unsigned long long)group_blkno,
 390			    (unsigned long long) bg_bh->b_blocknr);
 391		status = -EIO;
 392		goto bail;
 393	}
 394
 395	status = ocfs2_journal_access_gd(handle,
 396					 INODE_CACHE(alloc_inode),
 397					 bg_bh,
 398					 OCFS2_JOURNAL_ACCESS_CREATE);
 399	if (status < 0) {
 400		mlog_errno(status);
 401		goto bail;
 402	}
 403
 404	memset(bg, 0, sb->s_blocksize);
 405	strcpy(bg->bg_signature, OCFS2_GROUP_DESC_SIGNATURE);
 406	bg->bg_generation = cpu_to_le32(OCFS2_SB(sb)->fs_generation);
 407	bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb, 1,
 408						osb->s_feature_incompat));
 409	bg->bg_chain = cpu_to_le16(my_chain);
 410	bg->bg_next_group = cl->cl_recs[my_chain].c_blkno;
 411	bg->bg_parent_dinode = cpu_to_le64(OCFS2_I(alloc_inode)->ip_blkno);
 412	bg->bg_blkno = cpu_to_le64(group_blkno);
 413	if (group_clusters == le16_to_cpu(cl->cl_cpg))
 414		bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
 415	else
 416		ocfs2_bg_discontig_add_extent(osb, bg, cl, group_blkno,
 417					      group_clusters);
 418
 419	/* set the 1st bit in the bitmap to account for the descriptor block */
 420	ocfs2_set_bit(0, (unsigned long *)bg->bg_bitmap);
 421	bg->bg_free_bits_count = cpu_to_le16(le16_to_cpu(bg->bg_bits) - 1);
 422
 423	ocfs2_journal_dirty(handle, bg_bh);
 424
 425	/* There is no need to zero out or otherwise initialize the
 426	 * other blocks in a group - All valid FS metadata in a block
 427	 * group stores the superblock fs_generation value at
 428	 * allocation time. */
 429
 430bail:
 431	if (status)
 432		mlog_errno(status);
 433	return status;
 434}
 435
 436static inline u16 ocfs2_find_smallest_chain(struct ocfs2_chain_list *cl)
 437{
 438	u16 curr, best;
 439
 440	best = curr = 0;
 441	while (curr < le16_to_cpu(cl->cl_count)) {
 442		if (le32_to_cpu(cl->cl_recs[best].c_total) >
 443		    le32_to_cpu(cl->cl_recs[curr].c_total))
 444			best = curr;
 445		curr++;
 446	}
 447	return best;
 448}
 449
 450static struct buffer_head *
 451ocfs2_block_group_alloc_contig(struct ocfs2_super *osb, handle_t *handle,
 452			       struct inode *alloc_inode,
 453			       struct ocfs2_alloc_context *ac,
 454			       struct ocfs2_chain_list *cl)
 455{
 456	int status;
 457	u32 bit_off, num_bits;
 458	u64 bg_blkno;
 459	struct buffer_head *bg_bh;
 460	unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
 461
 462	status = ocfs2_claim_clusters(handle, ac,
 463				      le16_to_cpu(cl->cl_cpg), &bit_off,
 464				      &num_bits);
 465	if (status < 0) {
 466		if (status != -ENOSPC)
 467			mlog_errno(status);
 468		goto bail;
 469	}
 470
 471	/* setup the group */
 472	bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 473	trace_ocfs2_block_group_alloc_contig(
 474	     (unsigned long long)bg_blkno, alloc_rec);
 475
 476	bg_bh = sb_getblk(osb->sb, bg_blkno);
 477	if (!bg_bh) {
 478		status = -ENOMEM;
 479		mlog_errno(status);
 480		goto bail;
 481	}
 482	ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
 483
 484	status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
 485					bg_blkno, num_bits, alloc_rec, cl);
 486	if (status < 0) {
 487		brelse(bg_bh);
 488		mlog_errno(status);
 489	}
 490
 491bail:
 492	return status ? ERR_PTR(status) : bg_bh;
 493}
 494
 495static int ocfs2_block_group_claim_bits(struct ocfs2_super *osb,
 496					handle_t *handle,
 497					struct ocfs2_alloc_context *ac,
 498					unsigned int min_bits,
 499					u32 *bit_off, u32 *num_bits)
 500{
 501	int status = 0;
 502
 503	while (min_bits) {
 504		status = ocfs2_claim_clusters(handle, ac, min_bits,
 505					      bit_off, num_bits);
 506		if (status != -ENOSPC)
 507			break;
 508
 509		min_bits >>= 1;
 510	}
 511
 512	return status;
 513}
 514
 515static int ocfs2_block_group_grow_discontig(handle_t *handle,
 516					    struct inode *alloc_inode,
 517					    struct buffer_head *bg_bh,
 518					    struct ocfs2_alloc_context *ac,
 519					    struct ocfs2_chain_list *cl,
 520					    unsigned int min_bits)
 521{
 522	int status;
 523	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 524	struct ocfs2_group_desc *bg =
 525		(struct ocfs2_group_desc *)bg_bh->b_data;
 526	unsigned int needed = le16_to_cpu(cl->cl_cpg) -
 527			 le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
 528	u32 p_cpos, clusters;
 529	u64 p_blkno;
 530	struct ocfs2_extent_list *el = &bg->bg_list;
 531
 532	status = ocfs2_journal_access_gd(handle,
 533					 INODE_CACHE(alloc_inode),
 534					 bg_bh,
 535					 OCFS2_JOURNAL_ACCESS_CREATE);
 536	if (status < 0) {
 537		mlog_errno(status);
 538		goto bail;
 539	}
 540
 541	while ((needed > 0) && (le16_to_cpu(el->l_next_free_rec) <
 542				le16_to_cpu(el->l_count))) {
 543		if (min_bits > needed)
 544			min_bits = needed;
 545		status = ocfs2_block_group_claim_bits(osb, handle, ac,
 546						      min_bits, &p_cpos,
 547						      &clusters);
 548		if (status < 0) {
 549			if (status != -ENOSPC)
 550				mlog_errno(status);
 551			goto bail;
 552		}
 553		p_blkno = ocfs2_clusters_to_blocks(osb->sb, p_cpos);
 554		ocfs2_bg_discontig_add_extent(osb, bg, cl, p_blkno,
 555					      clusters);
 556
 557		min_bits = clusters;
 558		needed = le16_to_cpu(cl->cl_cpg) -
 559			 le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
 560	}
 561
 562	if (needed > 0) {
 563		/*
 564		 * We have used up all the extent rec but can't fill up
 565		 * the cpg. So bail out.
 566		 */
 567		status = -ENOSPC;
 568		goto bail;
 569	}
 570
 571	ocfs2_journal_dirty(handle, bg_bh);
 572
 573bail:
 574	return status;
 575}
 576
 577static void ocfs2_bg_alloc_cleanup(handle_t *handle,
 578				   struct ocfs2_alloc_context *cluster_ac,
 579				   struct inode *alloc_inode,
 580				   struct buffer_head *bg_bh)
 581{
 582	int i, ret;
 583	struct ocfs2_group_desc *bg;
 584	struct ocfs2_extent_list *el;
 585	struct ocfs2_extent_rec *rec;
 586
 587	if (!bg_bh)
 588		return;
 589
 590	bg = (struct ocfs2_group_desc *)bg_bh->b_data;
 591	el = &bg->bg_list;
 592	for (i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
 593		rec = &el->l_recs[i];
 594		ret = ocfs2_free_clusters(handle, cluster_ac->ac_inode,
 595					  cluster_ac->ac_bh,
 596					  le64_to_cpu(rec->e_blkno),
 597					  le16_to_cpu(rec->e_leaf_clusters));
 598		if (ret)
 599			mlog_errno(ret);
 600		/* Try all the clusters to free */
 601	}
 602
 603	ocfs2_remove_from_cache(INODE_CACHE(alloc_inode), bg_bh);
 604	brelse(bg_bh);
 605}
 606
 607static struct buffer_head *
 608ocfs2_block_group_alloc_discontig(handle_t *handle,
 609				  struct inode *alloc_inode,
 610				  struct ocfs2_alloc_context *ac,
 611				  struct ocfs2_chain_list *cl)
 612{
 613	int status;
 614	u32 bit_off, num_bits;
 615	u64 bg_blkno;
 616	unsigned int min_bits = le16_to_cpu(cl->cl_cpg) >> 1;
 617	struct buffer_head *bg_bh = NULL;
 618	unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
 619	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 620
 621	if (!ocfs2_supports_discontig_bg(osb)) {
 622		status = -ENOSPC;
 623		goto bail;
 624	}
 625
 626	status = ocfs2_extend_trans(handle,
 627				    ocfs2_calc_bg_discontig_credits(osb->sb));
 628	if (status) {
 629		mlog_errno(status);
 630		goto bail;
 631	}
 632
 633	/*
 634	 * We're going to be grabbing from multiple cluster groups.
 635	 * We don't have enough credits to relink them all, and the
 636	 * cluster groups will be staying in cache for the duration of
 637	 * this operation.
 638	 */
 639	ac->ac_disable_chain_relink = 1;
 640
 641	/* Claim the first region */
 642	status = ocfs2_block_group_claim_bits(osb, handle, ac, min_bits,
 643					      &bit_off, &num_bits);
 644	if (status < 0) {
 645		if (status != -ENOSPC)
 646			mlog_errno(status);
 647		goto bail;
 648	}
 649	min_bits = num_bits;
 650
 651	/* setup the group */
 652	bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 653	trace_ocfs2_block_group_alloc_discontig(
 654				(unsigned long long)bg_blkno, alloc_rec);
 655
 656	bg_bh = sb_getblk(osb->sb, bg_blkno);
 657	if (!bg_bh) {
 658		status = -ENOMEM;
 659		mlog_errno(status);
 660		goto bail;
 661	}
 662	ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
 663
 664	status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
 665					bg_blkno, num_bits, alloc_rec, cl);
 666	if (status < 0) {
 667		mlog_errno(status);
 668		goto bail;
 669	}
 670
 671	status = ocfs2_block_group_grow_discontig(handle, alloc_inode,
 672						  bg_bh, ac, cl, min_bits);
 673	if (status)
 674		mlog_errno(status);
 675
 676bail:
 677	if (status)
 678		ocfs2_bg_alloc_cleanup(handle, ac, alloc_inode, bg_bh);
 679	return status ? ERR_PTR(status) : bg_bh;
 680}
 681
 682/*
 683 * We expect the block group allocator to already be locked.
 684 */
 685static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
 686				   struct inode *alloc_inode,
 687				   struct buffer_head *bh,
 688				   u64 max_block,
 689				   u64 *last_alloc_group,
 690				   int flags)
 691{
 692	int status, credits;
 693	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) bh->b_data;
 694	struct ocfs2_chain_list *cl;
 695	struct ocfs2_alloc_context *ac = NULL;
 696	handle_t *handle = NULL;
 697	u16 alloc_rec;
 698	struct buffer_head *bg_bh = NULL;
 699	struct ocfs2_group_desc *bg;
 700
 701	BUG_ON(ocfs2_is_cluster_bitmap(alloc_inode));
 702
 703	cl = &fe->id2.i_chain;
 704	status = ocfs2_reserve_clusters_with_limit(osb,
 705						   le16_to_cpu(cl->cl_cpg),
 706						   max_block, flags, &ac);
 707	if (status < 0) {
 708		if (status != -ENOSPC)
 709			mlog_errno(status);
 710		goto bail;
 711	}
 712
 713	credits = ocfs2_calc_group_alloc_credits(osb->sb,
 714						 le16_to_cpu(cl->cl_cpg));
 715	handle = ocfs2_start_trans(osb, credits);
 716	if (IS_ERR(handle)) {
 717		status = PTR_ERR(handle);
 718		handle = NULL;
 719		mlog_errno(status);
 720		goto bail;
 721	}
 722
 723	if (last_alloc_group && *last_alloc_group != 0) {
 724		trace_ocfs2_block_group_alloc(
 725				(unsigned long long)*last_alloc_group);
 726		ac->ac_last_group = *last_alloc_group;
 727	}
 728
 729	bg_bh = ocfs2_block_group_alloc_contig(osb, handle, alloc_inode,
 730					       ac, cl);
 731	if (IS_ERR(bg_bh) && (PTR_ERR(bg_bh) == -ENOSPC))
 732		bg_bh = ocfs2_block_group_alloc_discontig(handle,
 733							  alloc_inode,
 734							  ac, cl);
 735	if (IS_ERR(bg_bh)) {
 736		status = PTR_ERR(bg_bh);
 737		bg_bh = NULL;
 738		if (status != -ENOSPC)
 739			mlog_errno(status);
 740		goto bail;
 741	}
 742	bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 743
 744	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
 745					 bh, OCFS2_JOURNAL_ACCESS_WRITE);
 746	if (status < 0) {
 747		mlog_errno(status);
 748		goto bail;
 749	}
 750
 751	alloc_rec = le16_to_cpu(bg->bg_chain);
 752	le32_add_cpu(&cl->cl_recs[alloc_rec].c_free,
 753		     le16_to_cpu(bg->bg_free_bits_count));
 754	le32_add_cpu(&cl->cl_recs[alloc_rec].c_total,
 755		     le16_to_cpu(bg->bg_bits));
 756	cl->cl_recs[alloc_rec].c_blkno = bg->bg_blkno;
 757	if (le16_to_cpu(cl->cl_next_free_rec) < le16_to_cpu(cl->cl_count))
 758		le16_add_cpu(&cl->cl_next_free_rec, 1);
 759
 760	le32_add_cpu(&fe->id1.bitmap1.i_used, le16_to_cpu(bg->bg_bits) -
 761					le16_to_cpu(bg->bg_free_bits_count));
 762	le32_add_cpu(&fe->id1.bitmap1.i_total, le16_to_cpu(bg->bg_bits));
 763	le32_add_cpu(&fe->i_clusters, le16_to_cpu(cl->cl_cpg));
 764
 765	ocfs2_journal_dirty(handle, bh);
 766
 767	spin_lock(&OCFS2_I(alloc_inode)->ip_lock);
 768	OCFS2_I(alloc_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
 769	fe->i_size = cpu_to_le64(ocfs2_clusters_to_bytes(alloc_inode->i_sb,
 770					     le32_to_cpu(fe->i_clusters)));
 771	spin_unlock(&OCFS2_I(alloc_inode)->ip_lock);
 772	i_size_write(alloc_inode, le64_to_cpu(fe->i_size));
 773	alloc_inode->i_blocks = ocfs2_inode_sector_count(alloc_inode);
 774	ocfs2_update_inode_fsync_trans(handle, alloc_inode, 0);
 775
 776	status = 0;
 777
 778	/* save the new last alloc group so that the caller can cache it. */
 779	if (last_alloc_group)
 780		*last_alloc_group = ac->ac_last_group;
 781
 782bail:
 783	if (handle)
 784		ocfs2_commit_trans(osb, handle);
 785
 786	if (ac)
 787		ocfs2_free_alloc_context(ac);
 788
 789	brelse(bg_bh);
 790
 791	if (status)
 792		mlog_errno(status);
 793	return status;
 794}
 795
 796static int ocfs2_reserve_suballoc_bits(struct ocfs2_super *osb,
 797				       struct ocfs2_alloc_context *ac,
 798				       int type,
 799				       u32 slot,
 800				       u64 *last_alloc_group,
 801				       int flags)
 802{
 803	int status;
 804	u32 bits_wanted = ac->ac_bits_wanted;
 805	struct inode *alloc_inode;
 806	struct buffer_head *bh = NULL;
 807	struct ocfs2_dinode *fe;
 808	u32 free_bits;
 809
 810	alloc_inode = ocfs2_get_system_file_inode(osb, type, slot);
 811	if (!alloc_inode) {
 812		mlog_errno(-EINVAL);
 813		return -EINVAL;
 814	}
 815
 816	mutex_lock(&alloc_inode->i_mutex);
 817
 818	status = ocfs2_inode_lock(alloc_inode, &bh, 1);
 819	if (status < 0) {
 820		mutex_unlock(&alloc_inode->i_mutex);
 821		iput(alloc_inode);
 822
 823		mlog_errno(status);
 824		return status;
 825	}
 826
 827	ac->ac_inode = alloc_inode;
 828	ac->ac_alloc_slot = slot;
 829
 830	fe = (struct ocfs2_dinode *) bh->b_data;
 831
 832	/* The bh was validated by the inode read inside
 833	 * ocfs2_inode_lock().  Any corruption is a code bug. */
 834	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
 835
 836	if (!(fe->i_flags & cpu_to_le32(OCFS2_CHAIN_FL))) {
 837		ocfs2_error(alloc_inode->i_sb, "Invalid chain allocator %llu",
 838			    (unsigned long long)le64_to_cpu(fe->i_blkno));
 839		status = -EIO;
 840		goto bail;
 841	}
 842
 843	free_bits = le32_to_cpu(fe->id1.bitmap1.i_total) -
 844		le32_to_cpu(fe->id1.bitmap1.i_used);
 845
 846	if (bits_wanted > free_bits) {
 847		/* cluster bitmap never grows */
 848		if (ocfs2_is_cluster_bitmap(alloc_inode)) {
 849			trace_ocfs2_reserve_suballoc_bits_nospc(bits_wanted,
 850								free_bits);
 851			status = -ENOSPC;
 852			goto bail;
 853		}
 854
 855		if (!(flags & ALLOC_NEW_GROUP)) {
 856			trace_ocfs2_reserve_suballoc_bits_no_new_group(
 857						slot, bits_wanted, free_bits);
 858			status = -ENOSPC;
 859			goto bail;
 860		}
 861
 862		status = ocfs2_block_group_alloc(osb, alloc_inode, bh,
 863						 ac->ac_max_block,
 864						 last_alloc_group, flags);
 865		if (status < 0) {
 866			if (status != -ENOSPC)
 867				mlog_errno(status);
 868			goto bail;
 869		}
 870		atomic_inc(&osb->alloc_stats.bg_extends);
 871
 872		/* You should never ask for this much metadata */
 873		BUG_ON(bits_wanted >
 874		       (le32_to_cpu(fe->id1.bitmap1.i_total)
 875			- le32_to_cpu(fe->id1.bitmap1.i_used)));
 876	}
 877
 878	get_bh(bh);
 879	ac->ac_bh = bh;
 880bail:
 881	brelse(bh);
 882
 883	if (status)
 884		mlog_errno(status);
 885	return status;
 886}
 887
 888static void ocfs2_init_inode_steal_slot(struct ocfs2_super *osb)
 889{
 890	spin_lock(&osb->osb_lock);
 891	osb->s_inode_steal_slot = OCFS2_INVALID_SLOT;
 892	spin_unlock(&osb->osb_lock);
 893	atomic_set(&osb->s_num_inodes_stolen, 0);
 894}
 895
 896static void ocfs2_init_meta_steal_slot(struct ocfs2_super *osb)
 897{
 898	spin_lock(&osb->osb_lock);
 899	osb->s_meta_steal_slot = OCFS2_INVALID_SLOT;
 900	spin_unlock(&osb->osb_lock);
 901	atomic_set(&osb->s_num_meta_stolen, 0);
 902}
 903
 904void ocfs2_init_steal_slots(struct ocfs2_super *osb)
 905{
 906	ocfs2_init_inode_steal_slot(osb);
 907	ocfs2_init_meta_steal_slot(osb);
 908}
 909
 910static void __ocfs2_set_steal_slot(struct ocfs2_super *osb, int slot, int type)
 911{
 912	spin_lock(&osb->osb_lock);
 913	if (type == INODE_ALLOC_SYSTEM_INODE)
 914		osb->s_inode_steal_slot = slot;
 915	else if (type == EXTENT_ALLOC_SYSTEM_INODE)
 916		osb->s_meta_steal_slot = slot;
 917	spin_unlock(&osb->osb_lock);
 918}
 919
 920static int __ocfs2_get_steal_slot(struct ocfs2_super *osb, int type)
 921{
 922	int slot = OCFS2_INVALID_SLOT;
 923
 924	spin_lock(&osb->osb_lock);
 925	if (type == INODE_ALLOC_SYSTEM_INODE)
 926		slot = osb->s_inode_steal_slot;
 927	else if (type == EXTENT_ALLOC_SYSTEM_INODE)
 928		slot = osb->s_meta_steal_slot;
 929	spin_unlock(&osb->osb_lock);
 930
 931	return slot;
 932}
 933
 934static int ocfs2_get_inode_steal_slot(struct ocfs2_super *osb)
 935{
 936	return __ocfs2_get_steal_slot(osb, INODE_ALLOC_SYSTEM_INODE);
 937}
 938
 939static int ocfs2_get_meta_steal_slot(struct ocfs2_super *osb)
 940{
 941	return __ocfs2_get_steal_slot(osb, EXTENT_ALLOC_SYSTEM_INODE);
 942}
 943
 944static int ocfs2_steal_resource(struct ocfs2_super *osb,
 945				struct ocfs2_alloc_context *ac,
 946				int type)
 947{
 948	int i, status = -ENOSPC;
 949	int slot = __ocfs2_get_steal_slot(osb, type);
 950
 951	/* Start to steal resource from the first slot after ours. */
 952	if (slot == OCFS2_INVALID_SLOT)
 953		slot = osb->slot_num + 1;
 954
 955	for (i = 0; i < osb->max_slots; i++, slot++) {
 956		if (slot == osb->max_slots)
 957			slot = 0;
 958
 959		if (slot == osb->slot_num)
 960			continue;
 961
 962		status = ocfs2_reserve_suballoc_bits(osb, ac,
 963						     type,
 964						     (u32)slot, NULL,
 965						     NOT_ALLOC_NEW_GROUP);
 966		if (status >= 0) {
 967			__ocfs2_set_steal_slot(osb, slot, type);
 968			break;
 969		}
 970
 971		ocfs2_free_ac_resource(ac);
 972	}
 973
 974	return status;
 975}
 976
 977static int ocfs2_steal_inode(struct ocfs2_super *osb,
 978			     struct ocfs2_alloc_context *ac)
 979{
 980	return ocfs2_steal_resource(osb, ac, INODE_ALLOC_SYSTEM_INODE);
 981}
 982
 983static int ocfs2_steal_meta(struct ocfs2_super *osb,
 984			    struct ocfs2_alloc_context *ac)
 985{
 986	return ocfs2_steal_resource(osb, ac, EXTENT_ALLOC_SYSTEM_INODE);
 987}
 988
 989int ocfs2_reserve_new_metadata_blocks(struct ocfs2_super *osb,
 990				      int blocks,
 991				      struct ocfs2_alloc_context **ac)
 992{
 993	int status;
 994	int slot = ocfs2_get_meta_steal_slot(osb);
 995
 996	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 997	if (!(*ac)) {
 998		status = -ENOMEM;
 999		mlog_errno(status);
1000		goto bail;
1001	}
1002
1003	(*ac)->ac_bits_wanted = blocks;
1004	(*ac)->ac_which = OCFS2_AC_USE_META;
1005	(*ac)->ac_group_search = ocfs2_block_group_search;
1006
1007	if (slot != OCFS2_INVALID_SLOT &&
1008		atomic_read(&osb->s_num_meta_stolen) < OCFS2_MAX_TO_STEAL)
1009		goto extent_steal;
1010
1011	atomic_set(&osb->s_num_meta_stolen, 0);
1012	status = ocfs2_reserve_suballoc_bits(osb, (*ac),
1013					     EXTENT_ALLOC_SYSTEM_INODE,
1014					     (u32)osb->slot_num, NULL,
1015					     ALLOC_GROUPS_FROM_GLOBAL|ALLOC_NEW_GROUP);
1016
1017
1018	if (status >= 0) {
1019		status = 0;
1020		if (slot != OCFS2_INVALID_SLOT)
1021			ocfs2_init_meta_steal_slot(osb);
1022		goto bail;
1023	} else if (status < 0 && status != -ENOSPC) {
1024		mlog_errno(status);
1025		goto bail;
1026	}
1027
1028	ocfs2_free_ac_resource(*ac);
1029
1030extent_steal:
1031	status = ocfs2_steal_meta(osb, *ac);
1032	atomic_inc(&osb->s_num_meta_stolen);
1033	if (status < 0) {
1034		if (status != -ENOSPC)
1035			mlog_errno(status);
1036		goto bail;
1037	}
1038
1039	status = 0;
1040bail:
1041	if ((status < 0) && *ac) {
1042		ocfs2_free_alloc_context(*ac);
1043		*ac = NULL;
1044	}
1045
1046	if (status)
1047		mlog_errno(status);
1048	return status;
1049}
1050
1051int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
1052			       struct ocfs2_extent_list *root_el,
1053			       struct ocfs2_alloc_context **ac)
1054{
1055	return ocfs2_reserve_new_metadata_blocks(osb,
1056					ocfs2_extend_meta_needed(root_el),
1057					ac);
1058}
1059
1060int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
1061			    struct ocfs2_alloc_context **ac)
1062{
1063	int status;
1064	int slot = ocfs2_get_inode_steal_slot(osb);
1065	u64 alloc_group;
1066
1067	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1068	if (!(*ac)) {
1069		status = -ENOMEM;
1070		mlog_errno(status);
1071		goto bail;
1072	}
1073
1074	(*ac)->ac_bits_wanted = 1;
1075	(*ac)->ac_which = OCFS2_AC_USE_INODE;
1076
1077	(*ac)->ac_group_search = ocfs2_block_group_search;
1078
1079	/*
1080	 * stat(2) can't handle i_ino > 32bits, so we tell the
1081	 * lower levels not to allocate us a block group past that
1082	 * limit.  The 'inode64' mount option avoids this behavior.
1083	 */
1084	if (!(osb->s_mount_opt & OCFS2_MOUNT_INODE64))
1085		(*ac)->ac_max_block = (u32)~0U;
1086
1087	/*
1088	 * slot is set when we successfully steal inode from other nodes.
1089	 * It is reset in 3 places:
1090	 * 1. when we flush the truncate log
1091	 * 2. when we complete local alloc recovery.
1092	 * 3. when we successfully allocate from our own slot.
1093	 * After it is set, we will go on stealing inodes until we find the
1094	 * need to check our slots to see whether there is some space for us.
1095	 */
1096	if (slot != OCFS2_INVALID_SLOT &&
1097	    atomic_read(&osb->s_num_inodes_stolen) < OCFS2_MAX_TO_STEAL)
1098		goto inode_steal;
1099
1100	atomic_set(&osb->s_num_inodes_stolen, 0);
1101	alloc_group = osb->osb_inode_alloc_group;
1102	status = ocfs2_reserve_suballoc_bits(osb, *ac,
1103					     INODE_ALLOC_SYSTEM_INODE,
1104					     (u32)osb->slot_num,
1105					     &alloc_group,
1106					     ALLOC_NEW_GROUP |
1107					     ALLOC_GROUPS_FROM_GLOBAL);
1108	if (status >= 0) {
1109		status = 0;
1110
1111		spin_lock(&osb->osb_lock);
1112		osb->osb_inode_alloc_group = alloc_group;
1113		spin_unlock(&osb->osb_lock);
1114		trace_ocfs2_reserve_new_inode_new_group(
1115			(unsigned long long)alloc_group);
1116
1117		/*
1118		 * Some inodes must be freed by us, so try to allocate
1119		 * from our own next time.
1120		 */
1121		if (slot != OCFS2_INVALID_SLOT)
1122			ocfs2_init_inode_steal_slot(osb);
1123		goto bail;
1124	} else if (status < 0 && status != -ENOSPC) {
1125		mlog_errno(status);
1126		goto bail;
1127	}
1128
1129	ocfs2_free_ac_resource(*ac);
1130
1131inode_steal:
1132	status = ocfs2_steal_inode(osb, *ac);
1133	atomic_inc(&osb->s_num_inodes_stolen);
1134	if (status < 0) {
1135		if (status != -ENOSPC)
1136			mlog_errno(status);
1137		goto bail;
1138	}
1139
1140	status = 0;
1141bail:
1142	if ((status < 0) && *ac) {
1143		ocfs2_free_alloc_context(*ac);
1144		*ac = NULL;
1145	}
1146
1147	if (status)
1148		mlog_errno(status);
1149	return status;
1150}
1151
1152/* local alloc code has to do the same thing, so rather than do this
1153 * twice.. */
1154int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
1155				      struct ocfs2_alloc_context *ac)
1156{
1157	int status;
1158
1159	ac->ac_which = OCFS2_AC_USE_MAIN;
1160	ac->ac_group_search = ocfs2_cluster_group_search;
1161
1162	status = ocfs2_reserve_suballoc_bits(osb, ac,
1163					     GLOBAL_BITMAP_SYSTEM_INODE,
1164					     OCFS2_INVALID_SLOT, NULL,
1165					     ALLOC_NEW_GROUP);
1166	if (status < 0 && status != -ENOSPC) {
1167		mlog_errno(status);
1168		goto bail;
1169	}
1170
1171bail:
1172	return status;
1173}
1174
1175/* Callers don't need to care which bitmap (local alloc or main) to
1176 * use so we figure it out for them, but unfortunately this clutters
1177 * things a bit. */
1178static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
1179					     u32 bits_wanted, u64 max_block,
1180					     int flags,
1181					     struct ocfs2_alloc_context **ac)
1182{
1183	int status;
 
1184
1185	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1186	if (!(*ac)) {
1187		status = -ENOMEM;
1188		mlog_errno(status);
1189		goto bail;
1190	}
1191
1192	(*ac)->ac_bits_wanted = bits_wanted;
1193	(*ac)->ac_max_block = max_block;
1194
1195	status = -ENOSPC;
1196	if (!(flags & ALLOC_GROUPS_FROM_GLOBAL) &&
1197	    ocfs2_alloc_should_use_local(osb, bits_wanted)) {
1198		status = ocfs2_reserve_local_alloc_bits(osb,
1199							bits_wanted,
1200							*ac);
1201		if ((status < 0) && (status != -ENOSPC)) {
1202			mlog_errno(status);
1203			goto bail;
1204		}
1205	}
1206
1207	if (status == -ENOSPC) {
 
1208		status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1209		if (status < 0) {
1210			if (status != -ENOSPC)
1211				mlog_errno(status);
1212			goto bail;
1213		}
1214	}
1215
1216	status = 0;
1217bail:
1218	if ((status < 0) && *ac) {
1219		ocfs2_free_alloc_context(*ac);
1220		*ac = NULL;
1221	}
1222
1223	if (status)
1224		mlog_errno(status);
1225	return status;
1226}
1227
1228int ocfs2_reserve_clusters(struct ocfs2_super *osb,
1229			   u32 bits_wanted,
1230			   struct ocfs2_alloc_context **ac)
1231{
1232	return ocfs2_reserve_clusters_with_limit(osb, bits_wanted, 0,
1233						 ALLOC_NEW_GROUP, ac);
1234}
1235
1236/*
1237 * More or less lifted from ext3. I'll leave their description below:
1238 *
1239 * "For ext3 allocations, we must not reuse any blocks which are
1240 * allocated in the bitmap buffer's "last committed data" copy.  This
1241 * prevents deletes from freeing up the page for reuse until we have
1242 * committed the delete transaction.
1243 *
1244 * If we didn't do this, then deleting something and reallocating it as
1245 * data would allow the old block to be overwritten before the
1246 * transaction committed (because we force data to disk before commit).
1247 * This would lead to corruption if we crashed between overwriting the
1248 * data and committing the delete.
1249 *
1250 * @@@ We may want to make this allocation behaviour conditional on
1251 * data-writes at some point, and disable it for metadata allocations or
1252 * sync-data inodes."
1253 *
1254 * Note: OCFS2 already does this differently for metadata vs data
1255 * allocations, as those bitmaps are separate and undo access is never
1256 * called on a metadata group descriptor.
1257 */
1258static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
1259					 int nr)
1260{
1261	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1262	int ret;
1263
1264	if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
1265		return 0;
1266
1267	if (!buffer_jbd(bg_bh))
1268		return 1;
1269
1270	jbd_lock_bh_state(bg_bh);
1271	bg = (struct ocfs2_group_desc *) bh2jh(bg_bh)->b_committed_data;
1272	if (bg)
1273		ret = !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
1274	else
1275		ret = 1;
1276	jbd_unlock_bh_state(bg_bh);
1277
1278	return ret;
1279}
1280
1281static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
1282					     struct buffer_head *bg_bh,
1283					     unsigned int bits_wanted,
1284					     unsigned int total_bits,
1285					     struct ocfs2_suballoc_result *res)
1286{
1287	void *bitmap;
1288	u16 best_offset, best_size;
1289	int offset, start, found, status = 0;
1290	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1291
1292	/* Callers got this descriptor from
1293	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1294	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1295
1296	found = start = best_offset = best_size = 0;
1297	bitmap = bg->bg_bitmap;
1298
1299	while((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) != -1) {
1300		if (offset == total_bits)
1301			break;
1302
1303		if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
1304			/* We found a zero, but we can't use it as it
1305			 * hasn't been put to disk yet! */
1306			found = 0;
1307			start = offset + 1;
1308		} else if (offset == start) {
1309			/* we found a zero */
1310			found++;
1311			/* move start to the next bit to test */
1312			start++;
1313		} else {
1314			/* got a zero after some ones */
1315			found = 1;
1316			start = offset + 1;
1317		}
1318		if (found > best_size) {
1319			best_size = found;
1320			best_offset = start - found;
1321		}
1322		/* we got everything we needed */
1323		if (found == bits_wanted) {
1324			/* mlog(0, "Found it all!\n"); */
1325			break;
1326		}
1327	}
1328
1329	if (best_size) {
1330		res->sr_bit_offset = best_offset;
1331		res->sr_bits = best_size;
1332	} else {
1333		status = -ENOSPC;
1334		/* No error log here -- see the comment above
1335		 * ocfs2_test_bg_bit_allocatable */
1336	}
1337
1338	return status;
1339}
1340
1341int ocfs2_block_group_set_bits(handle_t *handle,
1342					     struct inode *alloc_inode,
1343					     struct ocfs2_group_desc *bg,
1344					     struct buffer_head *group_bh,
1345					     unsigned int bit_off,
1346					     unsigned int num_bits)
1347{
1348	int status;
1349	void *bitmap = bg->bg_bitmap;
1350	int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1351
1352	/* All callers get the descriptor via
1353	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1354	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1355	BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
1356
1357	trace_ocfs2_block_group_set_bits(bit_off, num_bits);
1358
1359	if (ocfs2_is_cluster_bitmap(alloc_inode))
1360		journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1361
1362	status = ocfs2_journal_access_gd(handle,
1363					 INODE_CACHE(alloc_inode),
1364					 group_bh,
1365					 journal_type);
1366	if (status < 0) {
1367		mlog_errno(status);
1368		goto bail;
1369	}
1370
1371	le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
1372	if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
1373		ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit"
1374			    " count %u but claims %u are freed. num_bits %d",
1375			    (unsigned long long)le64_to_cpu(bg->bg_blkno),
1376			    le16_to_cpu(bg->bg_bits),
1377			    le16_to_cpu(bg->bg_free_bits_count), num_bits);
1378		return -EROFS;
1379	}
1380	while(num_bits--)
1381		ocfs2_set_bit(bit_off++, bitmap);
1382
1383	ocfs2_journal_dirty(handle, group_bh);
1384
1385bail:
1386	return status;
1387}
1388
1389/* find the one with the most empty bits */
1390static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
1391{
1392	u16 curr, best;
1393
1394	BUG_ON(!cl->cl_next_free_rec);
1395
1396	best = curr = 0;
1397	while (curr < le16_to_cpu(cl->cl_next_free_rec)) {
1398		if (le32_to_cpu(cl->cl_recs[curr].c_free) >
1399		    le32_to_cpu(cl->cl_recs[best].c_free))
1400			best = curr;
1401		curr++;
1402	}
1403
1404	BUG_ON(best >= le16_to_cpu(cl->cl_next_free_rec));
1405	return best;
1406}
1407
1408static int ocfs2_relink_block_group(handle_t *handle,
1409				    struct inode *alloc_inode,
1410				    struct buffer_head *fe_bh,
1411				    struct buffer_head *bg_bh,
1412				    struct buffer_head *prev_bg_bh,
1413				    u16 chain)
1414{
1415	int status;
1416	/* there is a really tiny chance the journal calls could fail,
1417	 * but we wouldn't want inconsistent blocks in *any* case. */
1418	u64 bg_ptr, prev_bg_ptr;
1419	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
1420	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1421	struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
1422
1423	/* The caller got these descriptors from
1424	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1425	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1426	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(prev_bg));
1427
1428	trace_ocfs2_relink_block_group(
1429		(unsigned long long)le64_to_cpu(fe->i_blkno), chain,
1430		(unsigned long long)le64_to_cpu(bg->bg_blkno),
1431		(unsigned long long)le64_to_cpu(prev_bg->bg_blkno));
1432
1433	bg_ptr = le64_to_cpu(bg->bg_next_group);
1434	prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
1435
1436	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1437					 prev_bg_bh,
1438					 OCFS2_JOURNAL_ACCESS_WRITE);
1439	if (status < 0)
1440		goto out;
1441
1442	prev_bg->bg_next_group = bg->bg_next_group;
1443	ocfs2_journal_dirty(handle, prev_bg_bh);
1444
1445	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1446					 bg_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1447	if (status < 0)
1448		goto out_rollback_prev_bg;
1449
1450	bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
1451	ocfs2_journal_dirty(handle, bg_bh);
1452
1453	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
1454					 fe_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1455	if (status < 0)
1456		goto out_rollback_bg;
1457
1458	fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
1459	ocfs2_journal_dirty(handle, fe_bh);
1460
1461out:
1462	if (status < 0)
1463		mlog_errno(status);
1464	return status;
1465
1466out_rollback_bg:
1467	bg->bg_next_group = cpu_to_le64(bg_ptr);
1468out_rollback_prev_bg:
1469	prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
1470	goto out;
1471}
1472
1473static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
1474						     u32 wanted)
1475{
1476	return le16_to_cpu(bg->bg_free_bits_count) > wanted;
1477}
1478
1479/* return 0 on success, -ENOSPC to keep searching and any other < 0
1480 * value on error. */
1481static int ocfs2_cluster_group_search(struct inode *inode,
1482				      struct buffer_head *group_bh,
1483				      u32 bits_wanted, u32 min_bits,
1484				      u64 max_block,
1485				      struct ocfs2_suballoc_result *res)
1486{
1487	int search = -ENOSPC;
1488	int ret;
1489	u64 blkoff;
1490	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
1491	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1492	unsigned int max_bits, gd_cluster_off;
1493
1494	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1495
1496	if (gd->bg_free_bits_count) {
1497		max_bits = le16_to_cpu(gd->bg_bits);
1498
1499		/* Tail groups in cluster bitmaps which aren't cpg
1500		 * aligned are prone to partial extension by a failed
1501		 * fs resize. If the file system resize never got to
1502		 * update the dinode cluster count, then we don't want
1503		 * to trust any clusters past it, regardless of what
1504		 * the group descriptor says. */
1505		gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
1506							  le64_to_cpu(gd->bg_blkno));
1507		if ((gd_cluster_off + max_bits) >
1508		    OCFS2_I(inode)->ip_clusters) {
1509			max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
1510			trace_ocfs2_cluster_group_search_wrong_max_bits(
1511				(unsigned long long)le64_to_cpu(gd->bg_blkno),
1512				le16_to_cpu(gd->bg_bits),
1513				OCFS2_I(inode)->ip_clusters, max_bits);
1514		}
1515
1516		ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1517							group_bh, bits_wanted,
1518							max_bits, res);
1519		if (ret)
1520			return ret;
1521
1522		if (max_block) {
1523			blkoff = ocfs2_clusters_to_blocks(inode->i_sb,
1524							  gd_cluster_off +
1525							  res->sr_bit_offset +
1526							  res->sr_bits);
1527			trace_ocfs2_cluster_group_search_max_block(
1528				(unsigned long long)blkoff,
1529				(unsigned long long)max_block);
1530			if (blkoff > max_block)
1531				return -ENOSPC;
1532		}
1533
1534		/* ocfs2_block_group_find_clear_bits() might
1535		 * return success, but we still want to return
1536		 * -ENOSPC unless it found the minimum number
1537		 * of bits. */
1538		if (min_bits <= res->sr_bits)
1539			search = 0; /* success */
1540		else if (res->sr_bits) {
1541			/*
1542			 * Don't show bits which we'll be returning
1543			 * for allocation to the local alloc bitmap.
1544			 */
1545			ocfs2_local_alloc_seen_free_bits(osb, res->sr_bits);
1546		}
1547	}
1548
1549	return search;
1550}
1551
1552static int ocfs2_block_group_search(struct inode *inode,
1553				    struct buffer_head *group_bh,
1554				    u32 bits_wanted, u32 min_bits,
1555				    u64 max_block,
1556				    struct ocfs2_suballoc_result *res)
1557{
1558	int ret = -ENOSPC;
1559	u64 blkoff;
1560	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
1561
1562	BUG_ON(min_bits != 1);
1563	BUG_ON(ocfs2_is_cluster_bitmap(inode));
1564
1565	if (bg->bg_free_bits_count) {
1566		ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1567							group_bh, bits_wanted,
1568							le16_to_cpu(bg->bg_bits),
1569							res);
1570		if (!ret && max_block) {
1571			blkoff = le64_to_cpu(bg->bg_blkno) +
1572				res->sr_bit_offset + res->sr_bits;
1573			trace_ocfs2_block_group_search_max_block(
1574				(unsigned long long)blkoff,
1575				(unsigned long long)max_block);
1576			if (blkoff > max_block)
1577				ret = -ENOSPC;
1578		}
1579	}
1580
1581	return ret;
1582}
1583
1584int ocfs2_alloc_dinode_update_counts(struct inode *inode,
1585				       handle_t *handle,
1586				       struct buffer_head *di_bh,
1587				       u32 num_bits,
1588				       u16 chain)
1589{
1590	int ret;
1591	u32 tmp_used;
1592	struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1593	struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &di->id2.i_chain;
1594
1595	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
1596				      OCFS2_JOURNAL_ACCESS_WRITE);
1597	if (ret < 0) {
1598		mlog_errno(ret);
1599		goto out;
1600	}
1601
1602	tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1603	di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
1604	le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
1605	ocfs2_journal_dirty(handle, di_bh);
1606
1607out:
1608	return ret;
1609}
1610
1611void ocfs2_rollback_alloc_dinode_counts(struct inode *inode,
1612				       struct buffer_head *di_bh,
1613				       u32 num_bits,
1614				       u16 chain)
1615{
1616	u32 tmp_used;
1617	struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1618	struct ocfs2_chain_list *cl;
1619
1620	cl = (struct ocfs2_chain_list *)&di->id2.i_chain;
1621	tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1622	di->id1.bitmap1.i_used = cpu_to_le32(tmp_used - num_bits);
1623	le32_add_cpu(&cl->cl_recs[chain].c_free, num_bits);
1624}
1625
1626static int ocfs2_bg_discontig_fix_by_rec(struct ocfs2_suballoc_result *res,
1627					 struct ocfs2_extent_rec *rec,
1628					 struct ocfs2_chain_list *cl)
1629{
1630	unsigned int bpc = le16_to_cpu(cl->cl_bpc);
1631	unsigned int bitoff = le32_to_cpu(rec->e_cpos) * bpc;
1632	unsigned int bitcount = le16_to_cpu(rec->e_leaf_clusters) * bpc;
1633
1634	if (res->sr_bit_offset < bitoff)
1635		return 0;
1636	if (res->sr_bit_offset >= (bitoff + bitcount))
1637		return 0;
1638	res->sr_blkno = le64_to_cpu(rec->e_blkno) +
1639		(res->sr_bit_offset - bitoff);
1640	if ((res->sr_bit_offset + res->sr_bits) > (bitoff + bitcount))
1641		res->sr_bits = (bitoff + bitcount) - res->sr_bit_offset;
1642	return 1;
1643}
1644
1645static void ocfs2_bg_discontig_fix_result(struct ocfs2_alloc_context *ac,
1646					  struct ocfs2_group_desc *bg,
1647					  struct ocfs2_suballoc_result *res)
1648{
1649	int i;
1650	u64 bg_blkno = res->sr_bg_blkno;  /* Save off */
1651	struct ocfs2_extent_rec *rec;
1652	struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1653	struct ocfs2_chain_list *cl = &di->id2.i_chain;
1654
1655	if (ocfs2_is_cluster_bitmap(ac->ac_inode)) {
1656		res->sr_blkno = 0;
1657		return;
1658	}
1659
1660	res->sr_blkno = res->sr_bg_blkno + res->sr_bit_offset;
1661	res->sr_bg_blkno = 0;  /* Clear it for contig block groups */
1662	if (!ocfs2_supports_discontig_bg(OCFS2_SB(ac->ac_inode->i_sb)) ||
1663	    !bg->bg_list.l_next_free_rec)
1664		return;
1665
1666	for (i = 0; i < le16_to_cpu(bg->bg_list.l_next_free_rec); i++) {
1667		rec = &bg->bg_list.l_recs[i];
1668		if (ocfs2_bg_discontig_fix_by_rec(res, rec, cl)) {
1669			res->sr_bg_blkno = bg_blkno;  /* Restore */
1670			break;
1671		}
1672	}
1673}
1674
1675static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
1676				  handle_t *handle,
1677				  u32 bits_wanted,
1678				  u32 min_bits,
1679				  struct ocfs2_suballoc_result *res,
1680				  u16 *bits_left)
1681{
1682	int ret;
1683	struct buffer_head *group_bh = NULL;
1684	struct ocfs2_group_desc *gd;
1685	struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1686	struct inode *alloc_inode = ac->ac_inode;
1687
1688	ret = ocfs2_read_group_descriptor(alloc_inode, di,
1689					  res->sr_bg_blkno, &group_bh);
1690	if (ret < 0) {
1691		mlog_errno(ret);
1692		return ret;
1693	}
1694
1695	gd = (struct ocfs2_group_desc *) group_bh->b_data;
1696	ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
1697				  ac->ac_max_block, res);
1698	if (ret < 0) {
1699		if (ret != -ENOSPC)
1700			mlog_errno(ret);
1701		goto out;
1702	}
1703
1704	if (!ret)
1705		ocfs2_bg_discontig_fix_result(ac, gd, res);
1706
1707	/*
1708	 * sr_bg_blkno might have been changed by
1709	 * ocfs2_bg_discontig_fix_result
1710	 */
1711	res->sr_bg_stable_blkno = group_bh->b_blocknr;
1712
1713	if (ac->ac_find_loc_only)
1714		goto out_loc_only;
1715
1716	ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
1717					       res->sr_bits,
1718					       le16_to_cpu(gd->bg_chain));
1719	if (ret < 0) {
1720		mlog_errno(ret);
1721		goto out;
1722	}
1723
1724	ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
1725					 res->sr_bit_offset, res->sr_bits);
1726	if (ret < 0) {
1727		ocfs2_rollback_alloc_dinode_counts(alloc_inode, ac->ac_bh,
1728					       res->sr_bits,
1729					       le16_to_cpu(gd->bg_chain));
1730		mlog_errno(ret);
1731	}
1732
1733out_loc_only:
1734	*bits_left = le16_to_cpu(gd->bg_free_bits_count);
1735
1736out:
1737	brelse(group_bh);
1738
1739	return ret;
1740}
1741
1742static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
1743			      handle_t *handle,
1744			      u32 bits_wanted,
1745			      u32 min_bits,
1746			      struct ocfs2_suballoc_result *res,
1747			      u16 *bits_left)
1748{
1749	int status;
1750	u16 chain;
1751	u64 next_group;
1752	struct inode *alloc_inode = ac->ac_inode;
1753	struct buffer_head *group_bh = NULL;
1754	struct buffer_head *prev_group_bh = NULL;
1755	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1756	struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1757	struct ocfs2_group_desc *bg;
1758
1759	chain = ac->ac_chain;
1760	trace_ocfs2_search_chain_begin(
1761		(unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
1762		bits_wanted, chain);
1763
1764	status = ocfs2_read_group_descriptor(alloc_inode, fe,
1765					     le64_to_cpu(cl->cl_recs[chain].c_blkno),
1766					     &group_bh);
1767	if (status < 0) {
1768		mlog_errno(status);
1769		goto bail;
1770	}
1771	bg = (struct ocfs2_group_desc *) group_bh->b_data;
1772
1773	status = -ENOSPC;
1774	/* for now, the chain search is a bit simplistic. We just use
1775	 * the 1st group with any empty bits. */
1776	while ((status = ac->ac_group_search(alloc_inode, group_bh,
1777					     bits_wanted, min_bits,
1778					     ac->ac_max_block,
1779					     res)) == -ENOSPC) {
1780		if (!bg->bg_next_group)
1781			break;
1782
1783		brelse(prev_group_bh);
1784		prev_group_bh = NULL;
1785
1786		next_group = le64_to_cpu(bg->bg_next_group);
1787		prev_group_bh = group_bh;
1788		group_bh = NULL;
1789		status = ocfs2_read_group_descriptor(alloc_inode, fe,
1790						     next_group, &group_bh);
1791		if (status < 0) {
1792			mlog_errno(status);
1793			goto bail;
1794		}
1795		bg = (struct ocfs2_group_desc *) group_bh->b_data;
1796	}
1797	if (status < 0) {
1798		if (status != -ENOSPC)
1799			mlog_errno(status);
1800		goto bail;
1801	}
1802
1803	trace_ocfs2_search_chain_succ(
1804		(unsigned long long)le64_to_cpu(bg->bg_blkno), res->sr_bits);
1805
1806	res->sr_bg_blkno = le64_to_cpu(bg->bg_blkno);
1807
1808	BUG_ON(res->sr_bits == 0);
1809	if (!status)
1810		ocfs2_bg_discontig_fix_result(ac, bg, res);
1811
1812	/*
1813	 * sr_bg_blkno might have been changed by
1814	 * ocfs2_bg_discontig_fix_result
1815	 */
1816	res->sr_bg_stable_blkno = group_bh->b_blocknr;
1817
1818	/*
1819	 * Keep track of previous block descriptor read. When
1820	 * we find a target, if we have read more than X
1821	 * number of descriptors, and the target is reasonably
1822	 * empty, relink him to top of his chain.
1823	 *
1824	 * We've read 0 extra blocks and only send one more to
1825	 * the transaction, yet the next guy to search has a
1826	 * much easier time.
1827	 *
1828	 * Do this *after* figuring out how many bits we're taking out
1829	 * of our target group.
1830	 */
1831	if (!ac->ac_disable_chain_relink &&
1832	    (prev_group_bh) &&
1833	    (ocfs2_block_group_reasonably_empty(bg, res->sr_bits))) {
1834		status = ocfs2_relink_block_group(handle, alloc_inode,
1835						  ac->ac_bh, group_bh,
1836						  prev_group_bh, chain);
1837		if (status < 0) {
1838			mlog_errno(status);
1839			goto bail;
1840		}
1841	}
1842
1843	if (ac->ac_find_loc_only)
1844		goto out_loc_only;
1845
1846	status = ocfs2_alloc_dinode_update_counts(alloc_inode, handle,
1847						  ac->ac_bh, res->sr_bits,
1848						  chain);
1849	if (status) {
1850		mlog_errno(status);
1851		goto bail;
1852	}
1853
1854	status = ocfs2_block_group_set_bits(handle,
1855					    alloc_inode,
1856					    bg,
1857					    group_bh,
1858					    res->sr_bit_offset,
1859					    res->sr_bits);
1860	if (status < 0) {
1861		ocfs2_rollback_alloc_dinode_counts(alloc_inode,
1862					ac->ac_bh, res->sr_bits, chain);
1863		mlog_errno(status);
1864		goto bail;
1865	}
1866
1867	trace_ocfs2_search_chain_end(
1868			(unsigned long long)le64_to_cpu(fe->i_blkno),
1869			res->sr_bits);
1870
1871out_loc_only:
1872	*bits_left = le16_to_cpu(bg->bg_free_bits_count);
1873bail:
1874	brelse(group_bh);
1875	brelse(prev_group_bh);
1876
1877	if (status)
1878		mlog_errno(status);
1879	return status;
1880}
1881
1882/* will give out up to bits_wanted contiguous bits. */
1883static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
1884				     handle_t *handle,
1885				     u32 bits_wanted,
1886				     u32 min_bits,
1887				     struct ocfs2_suballoc_result *res)
1888{
1889	int status;
1890	u16 victim, i;
1891	u16 bits_left = 0;
1892	u64 hint = ac->ac_last_group;
1893	struct ocfs2_chain_list *cl;
1894	struct ocfs2_dinode *fe;
1895
1896	BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1897	BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1898	BUG_ON(!ac->ac_bh);
1899
1900	fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1901
1902	/* The bh was validated by the inode read during
1903	 * ocfs2_reserve_suballoc_bits().  Any corruption is a code bug. */
1904	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
1905
1906	if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1907	    le32_to_cpu(fe->id1.bitmap1.i_total)) {
1908		ocfs2_error(ac->ac_inode->i_sb,
1909			    "Chain allocator dinode %llu has %u used "
1910			    "bits but only %u total.",
1911			    (unsigned long long)le64_to_cpu(fe->i_blkno),
1912			    le32_to_cpu(fe->id1.bitmap1.i_used),
1913			    le32_to_cpu(fe->id1.bitmap1.i_total));
1914		status = -EIO;
1915		goto bail;
1916	}
1917
1918	res->sr_bg_blkno = hint;
1919	if (res->sr_bg_blkno) {
1920		/* Attempt to short-circuit the usual search mechanism
1921		 * by jumping straight to the most recently used
1922		 * allocation group. This helps us maintain some
1923		 * contiguousness across allocations. */
1924		status = ocfs2_search_one_group(ac, handle, bits_wanted,
1925						min_bits, res, &bits_left);
1926		if (!status)
1927			goto set_hint;
1928		if (status < 0 && status != -ENOSPC) {
1929			mlog_errno(status);
1930			goto bail;
1931		}
1932	}
1933
1934	cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1935
1936	victim = ocfs2_find_victim_chain(cl);
1937	ac->ac_chain = victim;
1938
1939	status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1940				    res, &bits_left);
1941	if (!status) {
1942		hint = ocfs2_group_from_res(res);
 
 
 
1943		goto set_hint;
1944	}
1945	if (status < 0 && status != -ENOSPC) {
1946		mlog_errno(status);
1947		goto bail;
1948	}
1949
1950	trace_ocfs2_claim_suballoc_bits(victim);
1951
1952	/* If we didn't pick a good victim, then just default to
1953	 * searching each chain in order. Don't allow chain relinking
1954	 * because we only calculate enough journal credits for one
1955	 * relink per alloc. */
1956	ac->ac_disable_chain_relink = 1;
1957	for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
1958		if (i == victim)
1959			continue;
1960		if (!cl->cl_recs[i].c_free)
1961			continue;
1962
1963		ac->ac_chain = i;
1964		status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1965					    res, &bits_left);
1966		if (!status) {
1967			hint = ocfs2_group_from_res(res);
1968			break;
1969		}
1970		if (status < 0 && status != -ENOSPC) {
1971			mlog_errno(status);
1972			goto bail;
1973		}
1974	}
1975
1976set_hint:
1977	if (status != -ENOSPC) {
1978		/* If the next search of this group is not likely to
1979		 * yield a suitable extent, then we reset the last
1980		 * group hint so as to not waste a disk read */
1981		if (bits_left < min_bits)
1982			ac->ac_last_group = 0;
1983		else
1984			ac->ac_last_group = hint;
1985	}
1986
1987bail:
1988	if (status)
1989		mlog_errno(status);
1990	return status;
1991}
1992
1993int ocfs2_claim_metadata(handle_t *handle,
1994			 struct ocfs2_alloc_context *ac,
1995			 u32 bits_wanted,
1996			 u64 *suballoc_loc,
1997			 u16 *suballoc_bit_start,
1998			 unsigned int *num_bits,
1999			 u64 *blkno_start)
2000{
2001	int status;
2002	struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
2003
2004	BUG_ON(!ac);
2005	BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
2006	BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
2007
2008	status = ocfs2_claim_suballoc_bits(ac,
2009					   handle,
2010					   bits_wanted,
2011					   1,
2012					   &res);
2013	if (status < 0) {
2014		mlog_errno(status);
2015		goto bail;
2016	}
2017	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2018
2019	*suballoc_loc = res.sr_bg_blkno;
2020	*suballoc_bit_start = res.sr_bit_offset;
2021	*blkno_start = res.sr_blkno;
2022	ac->ac_bits_given += res.sr_bits;
2023	*num_bits = res.sr_bits;
2024	status = 0;
2025bail:
2026	if (status)
2027		mlog_errno(status);
2028	return status;
2029}
2030
2031static void ocfs2_init_inode_ac_group(struct inode *dir,
2032				      struct buffer_head *parent_di_bh,
2033				      struct ocfs2_alloc_context *ac)
2034{
2035	struct ocfs2_dinode *di = (struct ocfs2_dinode *)parent_di_bh->b_data;
2036	/*
2037	 * Try to allocate inodes from some specific group.
2038	 *
2039	 * If the parent dir has recorded the last group used in allocation,
2040	 * cool, use it. Otherwise if we try to allocate new inode from the
2041	 * same slot the parent dir belongs to, use the same chunk.
2042	 *
2043	 * We are very careful here to avoid the mistake of setting
2044	 * ac_last_group to a group descriptor from a different (unlocked) slot.
2045	 */
2046	if (OCFS2_I(dir)->ip_last_used_group &&
2047	    OCFS2_I(dir)->ip_last_used_slot == ac->ac_alloc_slot)
2048		ac->ac_last_group = OCFS2_I(dir)->ip_last_used_group;
2049	else if (le16_to_cpu(di->i_suballoc_slot) == ac->ac_alloc_slot) {
2050		if (di->i_suballoc_loc)
2051			ac->ac_last_group = le64_to_cpu(di->i_suballoc_loc);
2052		else
2053			ac->ac_last_group = ocfs2_which_suballoc_group(
2054					le64_to_cpu(di->i_blkno),
2055					le16_to_cpu(di->i_suballoc_bit));
2056	}
2057}
2058
2059static inline void ocfs2_save_inode_ac_group(struct inode *dir,
2060					     struct ocfs2_alloc_context *ac)
2061{
2062	OCFS2_I(dir)->ip_last_used_group = ac->ac_last_group;
2063	OCFS2_I(dir)->ip_last_used_slot = ac->ac_alloc_slot;
2064}
2065
2066int ocfs2_find_new_inode_loc(struct inode *dir,
2067			     struct buffer_head *parent_fe_bh,
2068			     struct ocfs2_alloc_context *ac,
2069			     u64 *fe_blkno)
2070{
2071	int ret;
2072	handle_t *handle = NULL;
2073	struct ocfs2_suballoc_result *res;
2074
2075	BUG_ON(!ac);
2076	BUG_ON(ac->ac_bits_given != 0);
2077	BUG_ON(ac->ac_bits_wanted != 1);
2078	BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2079
2080	res = kzalloc(sizeof(*res), GFP_NOFS);
2081	if (res == NULL) {
2082		ret = -ENOMEM;
2083		mlog_errno(ret);
2084		goto out;
2085	}
2086
2087	ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2088
2089	/*
2090	 * The handle started here is for chain relink. Alternatively,
2091	 * we could just disable relink for these calls.
2092	 */
2093	handle = ocfs2_start_trans(OCFS2_SB(dir->i_sb), OCFS2_SUBALLOC_ALLOC);
2094	if (IS_ERR(handle)) {
2095		ret = PTR_ERR(handle);
2096		handle = NULL;
2097		mlog_errno(ret);
2098		goto out;
2099	}
2100
2101	/*
2102	 * This will instruct ocfs2_claim_suballoc_bits and
2103	 * ocfs2_search_one_group to search but save actual allocation
2104	 * for later.
2105	 */
2106	ac->ac_find_loc_only = 1;
2107
2108	ret = ocfs2_claim_suballoc_bits(ac, handle, 1, 1, res);
2109	if (ret < 0) {
2110		mlog_errno(ret);
2111		goto out;
2112	}
2113
2114	ac->ac_find_loc_priv = res;
2115	*fe_blkno = res->sr_blkno;
2116	ocfs2_update_inode_fsync_trans(handle, dir, 0);
2117out:
2118	if (handle)
2119		ocfs2_commit_trans(OCFS2_SB(dir->i_sb), handle);
2120
2121	if (ret)
2122		kfree(res);
2123
2124	return ret;
2125}
2126
2127int ocfs2_claim_new_inode_at_loc(handle_t *handle,
2128				 struct inode *dir,
2129				 struct ocfs2_alloc_context *ac,
2130				 u64 *suballoc_loc,
2131				 u16 *suballoc_bit,
2132				 u64 di_blkno)
2133{
2134	int ret;
2135	u16 chain;
2136	struct ocfs2_suballoc_result *res = ac->ac_find_loc_priv;
2137	struct buffer_head *bg_bh = NULL;
2138	struct ocfs2_group_desc *bg;
2139	struct ocfs2_dinode *di = (struct ocfs2_dinode *) ac->ac_bh->b_data;
2140
2141	/*
2142	 * Since di_blkno is being passed back in, we check for any
2143	 * inconsistencies which may have happened between
2144	 * calls. These are code bugs as di_blkno is not expected to
2145	 * change once returned from ocfs2_find_new_inode_loc()
2146	 */
2147	BUG_ON(res->sr_blkno != di_blkno);
2148
2149	ret = ocfs2_read_group_descriptor(ac->ac_inode, di,
2150					  res->sr_bg_stable_blkno, &bg_bh);
2151	if (ret) {
2152		mlog_errno(ret);
2153		goto out;
2154	}
2155
2156	bg = (struct ocfs2_group_desc *) bg_bh->b_data;
2157	chain = le16_to_cpu(bg->bg_chain);
2158
2159	ret = ocfs2_alloc_dinode_update_counts(ac->ac_inode, handle,
2160					       ac->ac_bh, res->sr_bits,
2161					       chain);
2162	if (ret) {
2163		mlog_errno(ret);
2164		goto out;
2165	}
2166
2167	ret = ocfs2_block_group_set_bits(handle,
2168					 ac->ac_inode,
2169					 bg,
2170					 bg_bh,
2171					 res->sr_bit_offset,
2172					 res->sr_bits);
2173	if (ret < 0) {
2174		ocfs2_rollback_alloc_dinode_counts(ac->ac_inode,
2175					       ac->ac_bh, res->sr_bits, chain);
2176		mlog_errno(ret);
2177		goto out;
2178	}
2179
2180	trace_ocfs2_claim_new_inode_at_loc((unsigned long long)di_blkno,
2181					   res->sr_bits);
2182
2183	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2184
2185	BUG_ON(res->sr_bits != 1);
2186
2187	*suballoc_loc = res->sr_bg_blkno;
2188	*suballoc_bit = res->sr_bit_offset;
2189	ac->ac_bits_given++;
2190	ocfs2_save_inode_ac_group(dir, ac);
2191
2192out:
2193	brelse(bg_bh);
2194
2195	return ret;
2196}
2197
2198int ocfs2_claim_new_inode(handle_t *handle,
2199			  struct inode *dir,
2200			  struct buffer_head *parent_fe_bh,
2201			  struct ocfs2_alloc_context *ac,
2202			  u64 *suballoc_loc,
2203			  u16 *suballoc_bit,
2204			  u64 *fe_blkno)
2205{
2206	int status;
2207	struct ocfs2_suballoc_result res;
2208
2209	BUG_ON(!ac);
2210	BUG_ON(ac->ac_bits_given != 0);
2211	BUG_ON(ac->ac_bits_wanted != 1);
2212	BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2213
2214	ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2215
2216	status = ocfs2_claim_suballoc_bits(ac,
2217					   handle,
2218					   1,
2219					   1,
2220					   &res);
2221	if (status < 0) {
2222		mlog_errno(status);
2223		goto bail;
2224	}
2225	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2226
2227	BUG_ON(res.sr_bits != 1);
2228
2229	*suballoc_loc = res.sr_bg_blkno;
2230	*suballoc_bit = res.sr_bit_offset;
2231	*fe_blkno = res.sr_blkno;
2232	ac->ac_bits_given++;
2233	ocfs2_save_inode_ac_group(dir, ac);
2234	status = 0;
2235bail:
2236	if (status)
2237		mlog_errno(status);
2238	return status;
2239}
2240
2241/* translate a group desc. blkno and it's bitmap offset into
2242 * disk cluster offset. */
2243static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
2244						   u64 bg_blkno,
2245						   u16 bg_bit_off)
2246{
2247	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2248	u32 cluster = 0;
2249
2250	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2251
2252	if (bg_blkno != osb->first_cluster_group_blkno)
2253		cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
2254	cluster += (u32) bg_bit_off;
2255	return cluster;
2256}
2257
2258/* given a cluster offset, calculate which block group it belongs to
2259 * and return that block offset. */
2260u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster)
2261{
2262	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2263	u32 group_no;
2264
2265	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2266
2267	group_no = cluster / osb->bitmap_cpg;
2268	if (!group_no)
2269		return osb->first_cluster_group_blkno;
2270	return ocfs2_clusters_to_blocks(inode->i_sb,
2271					group_no * osb->bitmap_cpg);
2272}
2273
2274/* given the block number of a cluster start, calculate which cluster
2275 * group and descriptor bitmap offset that corresponds to. */
2276static inline void ocfs2_block_to_cluster_group(struct inode *inode,
2277						u64 data_blkno,
2278						u64 *bg_blkno,
2279						u16 *bg_bit_off)
2280{
2281	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2282	u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
2283
2284	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2285
2286	*bg_blkno = ocfs2_which_cluster_group(inode,
2287					      data_cluster);
2288
2289	if (*bg_blkno == osb->first_cluster_group_blkno)
2290		*bg_bit_off = (u16) data_cluster;
2291	else
2292		*bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
2293							     data_blkno - *bg_blkno);
2294}
2295
2296/*
2297 * min_bits - minimum contiguous chunk from this total allocation we
2298 * can handle. set to what we asked for originally for a full
2299 * contig. allocation, set to '1' to indicate we can deal with extents
2300 * of any size.
2301 */
2302int __ocfs2_claim_clusters(handle_t *handle,
2303			   struct ocfs2_alloc_context *ac,
2304			   u32 min_clusters,
2305			   u32 max_clusters,
2306			   u32 *cluster_start,
2307			   u32 *num_clusters)
2308{
2309	int status;
2310	unsigned int bits_wanted = max_clusters;
2311	struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
2312	struct ocfs2_super *osb = OCFS2_SB(ac->ac_inode->i_sb);
2313
2314	BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
2315
2316	BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
2317	       && ac->ac_which != OCFS2_AC_USE_MAIN);
2318
2319	if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
2320		WARN_ON(min_clusters > 1);
2321
2322		status = ocfs2_claim_local_alloc_bits(osb,
2323						      handle,
2324						      ac,
2325						      bits_wanted,
2326						      cluster_start,
2327						      num_clusters);
2328		if (!status)
2329			atomic_inc(&osb->alloc_stats.local_data);
2330	} else {
2331		if (min_clusters > (osb->bitmap_cpg - 1)) {
2332			/* The only paths asking for contiguousness
2333			 * should know about this already. */
2334			mlog(ML_ERROR, "minimum allocation requested %u exceeds "
2335			     "group bitmap size %u!\n", min_clusters,
2336			     osb->bitmap_cpg);
2337			status = -ENOSPC;
2338			goto bail;
2339		}
2340		/* clamp the current request down to a realistic size. */
2341		if (bits_wanted > (osb->bitmap_cpg - 1))
2342			bits_wanted = osb->bitmap_cpg - 1;
2343
2344		status = ocfs2_claim_suballoc_bits(ac,
2345						   handle,
2346						   bits_wanted,
2347						   min_clusters,
2348						   &res);
2349		if (!status) {
2350			BUG_ON(res.sr_blkno); /* cluster alloc can't set */
2351			*cluster_start =
2352				ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
2353								 res.sr_bg_blkno,
2354								 res.sr_bit_offset);
2355			atomic_inc(&osb->alloc_stats.bitmap_data);
2356			*num_clusters = res.sr_bits;
2357		}
2358	}
2359	if (status < 0) {
2360		if (status != -ENOSPC)
2361			mlog_errno(status);
2362		goto bail;
2363	}
2364
2365	ac->ac_bits_given += *num_clusters;
2366
2367bail:
2368	if (status)
2369		mlog_errno(status);
2370	return status;
2371}
2372
2373int ocfs2_claim_clusters(handle_t *handle,
2374			 struct ocfs2_alloc_context *ac,
2375			 u32 min_clusters,
2376			 u32 *cluster_start,
2377			 u32 *num_clusters)
2378{
2379	unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
2380
2381	return __ocfs2_claim_clusters(handle, ac, min_clusters,
2382				      bits_wanted, cluster_start, num_clusters);
2383}
2384
2385static int ocfs2_block_group_clear_bits(handle_t *handle,
2386					struct inode *alloc_inode,
2387					struct ocfs2_group_desc *bg,
2388					struct buffer_head *group_bh,
2389					unsigned int bit_off,
2390					unsigned int num_bits,
2391					void (*undo_fn)(unsigned int bit,
2392							unsigned long *bmap))
2393{
2394	int status;
2395	unsigned int tmp;
2396	struct ocfs2_group_desc *undo_bg = NULL;
2397
2398	/* The caller got this descriptor from
2399	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
2400	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
2401
2402	trace_ocfs2_block_group_clear_bits(bit_off, num_bits);
2403
2404	BUG_ON(undo_fn && !ocfs2_is_cluster_bitmap(alloc_inode));
2405	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
2406					 group_bh,
2407					 undo_fn ?
2408					 OCFS2_JOURNAL_ACCESS_UNDO :
2409					 OCFS2_JOURNAL_ACCESS_WRITE);
2410	if (status < 0) {
2411		mlog_errno(status);
2412		goto bail;
2413	}
2414
2415	if (undo_fn) {
2416		jbd_lock_bh_state(group_bh);
2417		undo_bg = (struct ocfs2_group_desc *)
2418					bh2jh(group_bh)->b_committed_data;
2419		BUG_ON(!undo_bg);
2420	}
2421
2422	tmp = num_bits;
2423	while(tmp--) {
2424		ocfs2_clear_bit((bit_off + tmp),
2425				(unsigned long *) bg->bg_bitmap);
2426		if (undo_fn)
2427			undo_fn(bit_off + tmp,
2428				(unsigned long *) undo_bg->bg_bitmap);
2429	}
2430	le16_add_cpu(&bg->bg_free_bits_count, num_bits);
2431	if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
2432		ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit"
2433			    " count %u but claims %u are freed. num_bits %d",
2434			    (unsigned long long)le64_to_cpu(bg->bg_blkno),
2435			    le16_to_cpu(bg->bg_bits),
2436			    le16_to_cpu(bg->bg_free_bits_count), num_bits);
2437		return -EROFS;
 
2438	}
2439
2440	if (undo_fn)
2441		jbd_unlock_bh_state(group_bh);
2442
2443	ocfs2_journal_dirty(handle, group_bh);
2444bail:
2445	return status;
2446}
2447
2448/*
2449 * expects the suballoc inode to already be locked.
2450 */
2451static int _ocfs2_free_suballoc_bits(handle_t *handle,
2452				     struct inode *alloc_inode,
2453				     struct buffer_head *alloc_bh,
2454				     unsigned int start_bit,
2455				     u64 bg_blkno,
2456				     unsigned int count,
2457				     void (*undo_fn)(unsigned int bit,
2458						     unsigned long *bitmap))
2459{
2460	int status = 0;
2461	u32 tmp_used;
2462	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
2463	struct ocfs2_chain_list *cl = &fe->id2.i_chain;
2464	struct buffer_head *group_bh = NULL;
2465	struct ocfs2_group_desc *group;
2466
2467	/* The alloc_bh comes from ocfs2_free_dinode() or
2468	 * ocfs2_free_clusters().  The callers have all locked the
2469	 * allocator and gotten alloc_bh from the lock call.  This
2470	 * validates the dinode buffer.  Any corruption that has happened
2471	 * is a code bug. */
2472	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
2473	BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
2474
2475	trace_ocfs2_free_suballoc_bits(
2476		(unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
2477		(unsigned long long)bg_blkno,
2478		start_bit, count);
2479
2480	status = ocfs2_read_group_descriptor(alloc_inode, fe, bg_blkno,
2481					     &group_bh);
2482	if (status < 0) {
2483		mlog_errno(status);
2484		goto bail;
2485	}
2486	group = (struct ocfs2_group_desc *) group_bh->b_data;
2487
2488	BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
2489
2490	status = ocfs2_block_group_clear_bits(handle, alloc_inode,
2491					      group, group_bh,
2492					      start_bit, count, undo_fn);
2493	if (status < 0) {
2494		mlog_errno(status);
2495		goto bail;
2496	}
2497
2498	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
2499					 alloc_bh, OCFS2_JOURNAL_ACCESS_WRITE);
2500	if (status < 0) {
2501		mlog_errno(status);
 
 
2502		goto bail;
2503	}
2504
2505	le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
2506		     count);
2507	tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
2508	fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
2509	ocfs2_journal_dirty(handle, alloc_bh);
2510
2511bail:
2512	brelse(group_bh);
2513
2514	if (status)
2515		mlog_errno(status);
2516	return status;
2517}
2518
2519int ocfs2_free_suballoc_bits(handle_t *handle,
2520			     struct inode *alloc_inode,
2521			     struct buffer_head *alloc_bh,
2522			     unsigned int start_bit,
2523			     u64 bg_blkno,
2524			     unsigned int count)
2525{
2526	return _ocfs2_free_suballoc_bits(handle, alloc_inode, alloc_bh,
2527					 start_bit, bg_blkno, count, NULL);
2528}
2529
2530int ocfs2_free_dinode(handle_t *handle,
2531		      struct inode *inode_alloc_inode,
2532		      struct buffer_head *inode_alloc_bh,
2533		      struct ocfs2_dinode *di)
2534{
2535	u64 blk = le64_to_cpu(di->i_blkno);
2536	u16 bit = le16_to_cpu(di->i_suballoc_bit);
2537	u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
2538
2539	if (di->i_suballoc_loc)
2540		bg_blkno = le64_to_cpu(di->i_suballoc_loc);
2541	return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
2542					inode_alloc_bh, bit, bg_blkno, 1);
2543}
2544
2545static int _ocfs2_free_clusters(handle_t *handle,
2546				struct inode *bitmap_inode,
2547				struct buffer_head *bitmap_bh,
2548				u64 start_blk,
2549				unsigned int num_clusters,
2550				void (*undo_fn)(unsigned int bit,
2551						unsigned long *bitmap))
2552{
2553	int status;
2554	u16 bg_start_bit;
2555	u64 bg_blkno;
2556	struct ocfs2_dinode *fe;
2557
2558	/* You can't ever have a contiguous set of clusters
2559	 * bigger than a block group bitmap so we never have to worry
2560	 * about looping on them.
2561	 * This is expensive. We can safely remove once this stuff has
2562	 * gotten tested really well. */
2563	BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb, ocfs2_blocks_to_clusters(bitmap_inode->i_sb, start_blk)));
 
 
2564
2565	fe = (struct ocfs2_dinode *) bitmap_bh->b_data;
2566
2567	ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
2568				     &bg_start_bit);
2569
2570	trace_ocfs2_free_clusters((unsigned long long)bg_blkno,
2571			(unsigned long long)start_blk,
2572			bg_start_bit, num_clusters);
2573
2574	status = _ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
2575					   bg_start_bit, bg_blkno,
2576					   num_clusters, undo_fn);
2577	if (status < 0) {
2578		mlog_errno(status);
2579		goto out;
2580	}
2581
2582	ocfs2_local_alloc_seen_free_bits(OCFS2_SB(bitmap_inode->i_sb),
2583					 num_clusters);
2584
2585out:
2586	if (status)
2587		mlog_errno(status);
2588	return status;
2589}
2590
2591int ocfs2_free_clusters(handle_t *handle,
2592			struct inode *bitmap_inode,
2593			struct buffer_head *bitmap_bh,
2594			u64 start_blk,
2595			unsigned int num_clusters)
2596{
2597	return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2598				    start_blk, num_clusters,
2599				    _ocfs2_set_bit);
2600}
2601
2602/*
2603 * Give never-used clusters back to the global bitmap.  We don't need
2604 * to protect these bits in the undo buffer.
2605 */
2606int ocfs2_release_clusters(handle_t *handle,
2607			   struct inode *bitmap_inode,
2608			   struct buffer_head *bitmap_bh,
2609			   u64 start_blk,
2610			   unsigned int num_clusters)
2611{
2612	return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2613				    start_blk, num_clusters,
2614				    _ocfs2_clear_bit);
2615}
2616
2617static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg)
2618{
2619	printk("Block Group:\n");
2620	printk("bg_signature:       %s\n", bg->bg_signature);
2621	printk("bg_size:            %u\n", bg->bg_size);
2622	printk("bg_bits:            %u\n", bg->bg_bits);
2623	printk("bg_free_bits_count: %u\n", bg->bg_free_bits_count);
2624	printk("bg_chain:           %u\n", bg->bg_chain);
2625	printk("bg_generation:      %u\n", le32_to_cpu(bg->bg_generation));
2626	printk("bg_next_group:      %llu\n",
2627	       (unsigned long long)bg->bg_next_group);
2628	printk("bg_parent_dinode:   %llu\n",
2629	       (unsigned long long)bg->bg_parent_dinode);
2630	printk("bg_blkno:           %llu\n",
2631	       (unsigned long long)bg->bg_blkno);
2632}
2633
2634static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe)
2635{
2636	int i;
2637
2638	printk("Suballoc Inode %llu:\n", (unsigned long long)fe->i_blkno);
2639	printk("i_signature:                  %s\n", fe->i_signature);
2640	printk("i_size:                       %llu\n",
2641	       (unsigned long long)fe->i_size);
2642	printk("i_clusters:                   %u\n", fe->i_clusters);
2643	printk("i_generation:                 %u\n",
2644	       le32_to_cpu(fe->i_generation));
2645	printk("id1.bitmap1.i_used:           %u\n",
2646	       le32_to_cpu(fe->id1.bitmap1.i_used));
2647	printk("id1.bitmap1.i_total:          %u\n",
2648	       le32_to_cpu(fe->id1.bitmap1.i_total));
2649	printk("id2.i_chain.cl_cpg:           %u\n", fe->id2.i_chain.cl_cpg);
2650	printk("id2.i_chain.cl_bpc:           %u\n", fe->id2.i_chain.cl_bpc);
2651	printk("id2.i_chain.cl_count:         %u\n", fe->id2.i_chain.cl_count);
2652	printk("id2.i_chain.cl_next_free_rec: %u\n",
2653	       fe->id2.i_chain.cl_next_free_rec);
2654	for(i = 0; i < fe->id2.i_chain.cl_next_free_rec; i++) {
2655		printk("fe->id2.i_chain.cl_recs[%d].c_free:  %u\n", i,
2656		       fe->id2.i_chain.cl_recs[i].c_free);
2657		printk("fe->id2.i_chain.cl_recs[%d].c_total: %u\n", i,
2658		       fe->id2.i_chain.cl_recs[i].c_total);
2659		printk("fe->id2.i_chain.cl_recs[%d].c_blkno: %llu\n", i,
2660		       (unsigned long long)fe->id2.i_chain.cl_recs[i].c_blkno);
2661	}
2662}
2663
2664/*
2665 * For a given allocation, determine which allocators will need to be
2666 * accessed, and lock them, reserving the appropriate number of bits.
2667 *
2668 * Sparse file systems call this from ocfs2_write_begin_nolock()
2669 * and ocfs2_allocate_unwritten_extents().
2670 *
2671 * File systems which don't support holes call this from
2672 * ocfs2_extend_allocation().
2673 */
2674int ocfs2_lock_allocators(struct inode *inode,
2675			  struct ocfs2_extent_tree *et,
2676			  u32 clusters_to_add, u32 extents_to_split,
2677			  struct ocfs2_alloc_context **data_ac,
2678			  struct ocfs2_alloc_context **meta_ac)
2679{
2680	int ret = 0, num_free_extents;
2681	unsigned int max_recs_needed = clusters_to_add + 2 * extents_to_split;
2682	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2683
2684	*meta_ac = NULL;
2685	if (data_ac)
2686		*data_ac = NULL;
2687
2688	BUG_ON(clusters_to_add != 0 && data_ac == NULL);
2689
2690	num_free_extents = ocfs2_num_free_extents(osb, et);
2691	if (num_free_extents < 0) {
2692		ret = num_free_extents;
2693		mlog_errno(ret);
2694		goto out;
2695	}
2696
2697	/*
2698	 * Sparse allocation file systems need to be more conservative
2699	 * with reserving room for expansion - the actual allocation
2700	 * happens while we've got a journal handle open so re-taking
2701	 * a cluster lock (because we ran out of room for another
2702	 * extent) will violate ordering rules.
2703	 *
2704	 * Most of the time we'll only be seeing this 1 cluster at a time
2705	 * anyway.
2706	 *
2707	 * Always lock for any unwritten extents - we might want to
2708	 * add blocks during a split.
2709	 */
2710	if (!num_free_extents ||
2711	    (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed)) {
2712		ret = ocfs2_reserve_new_metadata(osb, et->et_root_el, meta_ac);
2713		if (ret < 0) {
2714			if (ret != -ENOSPC)
2715				mlog_errno(ret);
2716			goto out;
2717		}
2718	}
2719
2720	if (clusters_to_add == 0)
2721		goto out;
2722
2723	ret = ocfs2_reserve_clusters(osb, clusters_to_add, data_ac);
2724	if (ret < 0) {
2725		if (ret != -ENOSPC)
2726			mlog_errno(ret);
2727		goto out;
2728	}
2729
2730out:
2731	if (ret) {
2732		if (*meta_ac) {
2733			ocfs2_free_alloc_context(*meta_ac);
2734			*meta_ac = NULL;
2735		}
2736
2737		/*
2738		 * We cannot have an error and a non null *data_ac.
2739		 */
2740	}
2741
2742	return ret;
2743}
2744
2745/*
2746 * Read the inode specified by blkno to get suballoc_slot and
2747 * suballoc_bit.
2748 */
2749static int ocfs2_get_suballoc_slot_bit(struct ocfs2_super *osb, u64 blkno,
2750				       u16 *suballoc_slot, u64 *group_blkno,
2751				       u16 *suballoc_bit)
2752{
2753	int status;
2754	struct buffer_head *inode_bh = NULL;
2755	struct ocfs2_dinode *inode_fe;
2756
2757	trace_ocfs2_get_suballoc_slot_bit((unsigned long long)blkno);
2758
2759	/* dirty read disk */
2760	status = ocfs2_read_blocks_sync(osb, blkno, 1, &inode_bh);
2761	if (status < 0) {
2762		mlog(ML_ERROR, "read block %llu failed %d\n",
2763		     (unsigned long long)blkno, status);
2764		goto bail;
2765	}
2766
2767	inode_fe = (struct ocfs2_dinode *) inode_bh->b_data;
2768	if (!OCFS2_IS_VALID_DINODE(inode_fe)) {
2769		mlog(ML_ERROR, "invalid inode %llu requested\n",
2770		     (unsigned long long)blkno);
2771		status = -EINVAL;
2772		goto bail;
2773	}
2774
2775	if (le16_to_cpu(inode_fe->i_suballoc_slot) != (u16)OCFS2_INVALID_SLOT &&
2776	    (u32)le16_to_cpu(inode_fe->i_suballoc_slot) > osb->max_slots - 1) {
2777		mlog(ML_ERROR, "inode %llu has invalid suballoc slot %u\n",
2778		     (unsigned long long)blkno,
2779		     (u32)le16_to_cpu(inode_fe->i_suballoc_slot));
2780		status = -EINVAL;
2781		goto bail;
2782	}
2783
2784	if (suballoc_slot)
2785		*suballoc_slot = le16_to_cpu(inode_fe->i_suballoc_slot);
2786	if (suballoc_bit)
2787		*suballoc_bit = le16_to_cpu(inode_fe->i_suballoc_bit);
2788	if (group_blkno)
2789		*group_blkno = le64_to_cpu(inode_fe->i_suballoc_loc);
2790
2791bail:
2792	brelse(inode_bh);
2793
2794	if (status)
2795		mlog_errno(status);
2796	return status;
2797}
2798
2799/*
2800 * test whether bit is SET in allocator bitmap or not.  on success, 0
2801 * is returned and *res is 1 for SET; 0 otherwise.  when fails, errno
2802 * is returned and *res is meaningless.  Call this after you have
2803 * cluster locked against suballoc, or you may get a result based on
2804 * non-up2date contents
2805 */
2806static int ocfs2_test_suballoc_bit(struct ocfs2_super *osb,
2807				   struct inode *suballoc,
2808				   struct buffer_head *alloc_bh,
2809				   u64 group_blkno, u64 blkno,
2810				   u16 bit, int *res)
2811{
2812	struct ocfs2_dinode *alloc_di;
2813	struct ocfs2_group_desc *group;
2814	struct buffer_head *group_bh = NULL;
2815	u64 bg_blkno;
2816	int status;
2817
2818	trace_ocfs2_test_suballoc_bit((unsigned long long)blkno,
2819				      (unsigned int)bit);
2820
2821	alloc_di = (struct ocfs2_dinode *)alloc_bh->b_data;
2822	if ((bit + 1) > ocfs2_bits_per_group(&alloc_di->id2.i_chain)) {
2823		mlog(ML_ERROR, "suballoc bit %u out of range of %u\n",
2824		     (unsigned int)bit,
2825		     ocfs2_bits_per_group(&alloc_di->id2.i_chain));
2826		status = -EINVAL;
2827		goto bail;
2828	}
2829
2830	bg_blkno = group_blkno ? group_blkno :
2831		   ocfs2_which_suballoc_group(blkno, bit);
2832	status = ocfs2_read_group_descriptor(suballoc, alloc_di, bg_blkno,
2833					     &group_bh);
2834	if (status < 0) {
2835		mlog(ML_ERROR, "read group %llu failed %d\n",
2836		     (unsigned long long)bg_blkno, status);
2837		goto bail;
2838	}
2839
2840	group = (struct ocfs2_group_desc *) group_bh->b_data;
2841	*res = ocfs2_test_bit(bit, (unsigned long *)group->bg_bitmap);
2842
2843bail:
2844	brelse(group_bh);
2845
2846	if (status)
2847		mlog_errno(status);
2848	return status;
2849}
2850
2851/*
2852 * Test if the bit representing this inode (blkno) is set in the
2853 * suballocator.
2854 *
2855 * On success, 0 is returned and *res is 1 for SET; 0 otherwise.
2856 *
2857 * In the event of failure, a negative value is returned and *res is
2858 * meaningless.
2859 *
2860 * Callers must make sure to hold nfs_sync_lock to prevent
2861 * ocfs2_delete_inode() on another node from accessing the same
2862 * suballocator concurrently.
2863 */
2864int ocfs2_test_inode_bit(struct ocfs2_super *osb, u64 blkno, int *res)
2865{
2866	int status;
2867	u64 group_blkno = 0;
2868	u16 suballoc_bit = 0, suballoc_slot = 0;
2869	struct inode *inode_alloc_inode;
2870	struct buffer_head *alloc_bh = NULL;
2871
2872	trace_ocfs2_test_inode_bit((unsigned long long)blkno);
2873
2874	status = ocfs2_get_suballoc_slot_bit(osb, blkno, &suballoc_slot,
2875					     &group_blkno, &suballoc_bit);
2876	if (status < 0) {
2877		mlog(ML_ERROR, "get alloc slot and bit failed %d\n", status);
2878		goto bail;
2879	}
2880
2881	inode_alloc_inode =
2882		ocfs2_get_system_file_inode(osb, INODE_ALLOC_SYSTEM_INODE,
2883					    suballoc_slot);
2884	if (!inode_alloc_inode) {
2885		/* the error code could be inaccurate, but we are not able to
2886		 * get the correct one. */
2887		status = -EINVAL;
2888		mlog(ML_ERROR, "unable to get alloc inode in slot %u\n",
2889		     (u32)suballoc_slot);
2890		goto bail;
2891	}
2892
2893	mutex_lock(&inode_alloc_inode->i_mutex);
2894	status = ocfs2_inode_lock(inode_alloc_inode, &alloc_bh, 0);
2895	if (status < 0) {
2896		mutex_unlock(&inode_alloc_inode->i_mutex);
2897		iput(inode_alloc_inode);
2898		mlog(ML_ERROR, "lock on alloc inode on slot %u failed %d\n",
2899		     (u32)suballoc_slot, status);
2900		goto bail;
2901	}
2902
2903	status = ocfs2_test_suballoc_bit(osb, inode_alloc_inode, alloc_bh,
2904					 group_blkno, blkno, suballoc_bit, res);
2905	if (status < 0)
2906		mlog(ML_ERROR, "test suballoc bit failed %d\n", status);
2907
2908	ocfs2_inode_unlock(inode_alloc_inode, 0);
2909	mutex_unlock(&inode_alloc_inode->i_mutex);
2910
2911	iput(inode_alloc_inode);
2912	brelse(alloc_bh);
2913bail:
2914	if (status)
2915		mlog_errno(status);
2916	return status;
2917}
v4.17
   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 u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl);
  83static int ocfs2_block_group_fill(handle_t *handle,
  84				  struct inode *alloc_inode,
  85				  struct buffer_head *bg_bh,
  86				  u64 group_blkno,
  87				  unsigned int group_clusters,
  88				  u16 my_chain,
  89				  struct ocfs2_chain_list *cl);
  90static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
  91				   struct inode *alloc_inode,
  92				   struct buffer_head *bh,
  93				   u64 max_block,
  94				   u64 *last_alloc_group,
  95				   int flags);
  96
  97static int ocfs2_cluster_group_search(struct inode *inode,
  98				      struct buffer_head *group_bh,
  99				      u32 bits_wanted, u32 min_bits,
 100				      u64 max_block,
 101				      struct ocfs2_suballoc_result *res);
 102static int ocfs2_block_group_search(struct inode *inode,
 103				    struct buffer_head *group_bh,
 104				    u32 bits_wanted, u32 min_bits,
 105				    u64 max_block,
 106				    struct ocfs2_suballoc_result *res);
 107static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
 108				     handle_t *handle,
 109				     u32 bits_wanted,
 110				     u32 min_bits,
 111				     struct ocfs2_suballoc_result *res);
 112static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
 113					 int nr);
 114static int ocfs2_relink_block_group(handle_t *handle,
 115				    struct inode *alloc_inode,
 116				    struct buffer_head *fe_bh,
 117				    struct buffer_head *bg_bh,
 118				    struct buffer_head *prev_bg_bh,
 119				    u16 chain);
 120static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
 121						     u32 wanted);
 122static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
 123						   u64 bg_blkno,
 124						   u16 bg_bit_off);
 125static inline void ocfs2_block_to_cluster_group(struct inode *inode,
 126						u64 data_blkno,
 127						u64 *bg_blkno,
 128						u16 *bg_bit_off);
 129static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
 130					     u32 bits_wanted, u64 max_block,
 131					     int flags,
 132					     struct ocfs2_alloc_context **ac);
 133
 134void ocfs2_free_ac_resource(struct ocfs2_alloc_context *ac)
 135{
 136	struct inode *inode = ac->ac_inode;
 137
 138	if (inode) {
 139		if (ac->ac_which != OCFS2_AC_USE_LOCAL)
 140			ocfs2_inode_unlock(inode, 1);
 141
 142		inode_unlock(inode);
 143
 144		iput(inode);
 145		ac->ac_inode = NULL;
 146	}
 147	brelse(ac->ac_bh);
 148	ac->ac_bh = NULL;
 149	ac->ac_resv = NULL;
 150	kfree(ac->ac_find_loc_priv);
 151	ac->ac_find_loc_priv = NULL;
 
 
 152}
 153
 154void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
 155{
 156	ocfs2_free_ac_resource(ac);
 157	kfree(ac);
 158}
 159
 160static u32 ocfs2_bits_per_group(struct ocfs2_chain_list *cl)
 161{
 162	return (u32)le16_to_cpu(cl->cl_cpg) * (u32)le16_to_cpu(cl->cl_bpc);
 163}
 164
 165#define do_error(fmt, ...)						\
 166do {									\
 167	if (resize)							\
 168		mlog(ML_ERROR, fmt, ##__VA_ARGS__);			\
 169	else								\
 170		return ocfs2_error(sb, fmt, ##__VA_ARGS__);		\
 171} while (0)
 172
 173static int ocfs2_validate_gd_self(struct super_block *sb,
 174				  struct buffer_head *bh,
 175				  int resize)
 176{
 177	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 178
 179	if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
 180		do_error("Group descriptor #%llu has bad signature %.*s\n",
 181			 (unsigned long long)bh->b_blocknr, 7,
 182			 gd->bg_signature);
 
 183	}
 184
 185	if (le64_to_cpu(gd->bg_blkno) != bh->b_blocknr) {
 186		do_error("Group descriptor #%llu has an invalid bg_blkno of %llu\n",
 
 187			 (unsigned long long)bh->b_blocknr,
 188			 (unsigned long long)le64_to_cpu(gd->bg_blkno));
 
 189	}
 190
 191	if (le32_to_cpu(gd->bg_generation) != OCFS2_SB(sb)->fs_generation) {
 192		do_error("Group descriptor #%llu has an invalid fs_generation of #%u\n",
 
 193			 (unsigned long long)bh->b_blocknr,
 194			 le32_to_cpu(gd->bg_generation));
 
 195	}
 196
 197	if (le16_to_cpu(gd->bg_free_bits_count) > le16_to_cpu(gd->bg_bits)) {
 198		do_error("Group descriptor #%llu has bit count %u but claims that %u are free\n",
 
 199			 (unsigned long long)bh->b_blocknr,
 200			 le16_to_cpu(gd->bg_bits),
 201			 le16_to_cpu(gd->bg_free_bits_count));
 
 202	}
 203
 204	if (le16_to_cpu(gd->bg_bits) > (8 * le16_to_cpu(gd->bg_size))) {
 205		do_error("Group descriptor #%llu has bit count %u but max bitmap bits of %u\n",
 
 206			 (unsigned long long)bh->b_blocknr,
 207			 le16_to_cpu(gd->bg_bits),
 208			 8 * le16_to_cpu(gd->bg_size));
 
 209	}
 210
 211	return 0;
 212}
 213
 214static int ocfs2_validate_gd_parent(struct super_block *sb,
 215				    struct ocfs2_dinode *di,
 216				    struct buffer_head *bh,
 217				    int resize)
 218{
 219	unsigned int max_bits;
 220	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 221
 222	if (di->i_blkno != gd->bg_parent_dinode) {
 223		do_error("Group descriptor #%llu has bad parent pointer (%llu, expected %llu)\n",
 
 224			 (unsigned long long)bh->b_blocknr,
 225			 (unsigned long long)le64_to_cpu(gd->bg_parent_dinode),
 226			 (unsigned long long)le64_to_cpu(di->i_blkno));
 
 227	}
 228
 229	max_bits = le16_to_cpu(di->id2.i_chain.cl_cpg) * le16_to_cpu(di->id2.i_chain.cl_bpc);
 230	if (le16_to_cpu(gd->bg_bits) > max_bits) {
 231		do_error("Group descriptor #%llu has bit count of %u\n",
 232			 (unsigned long long)bh->b_blocknr,
 233			 le16_to_cpu(gd->bg_bits));
 
 234	}
 235
 236	/* In resize, we may meet the case bg_chain == cl_next_free_rec. */
 237	if ((le16_to_cpu(gd->bg_chain) >
 238	     le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) ||
 239	    ((le16_to_cpu(gd->bg_chain) ==
 240	     le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) && !resize)) {
 241		do_error("Group descriptor #%llu has bad chain %u\n",
 242			 (unsigned long long)bh->b_blocknr,
 243			 le16_to_cpu(gd->bg_chain));
 
 244	}
 245
 246	return 0;
 247}
 248
 249#undef do_error
 250
 251/*
 252 * This version only prints errors.  It does not fail the filesystem, and
 253 * exists only for resize.
 254 */
 255int ocfs2_check_group_descriptor(struct super_block *sb,
 256				 struct ocfs2_dinode *di,
 257				 struct buffer_head *bh)
 258{
 259	int rc;
 260	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 261
 262	BUG_ON(!buffer_uptodate(bh));
 263
 264	/*
 265	 * If the ecc fails, we return the error but otherwise
 266	 * leave the filesystem running.  We know any error is
 267	 * local to this block.
 268	 */
 269	rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
 270	if (rc) {
 271		mlog(ML_ERROR,
 272		     "Checksum failed for group descriptor %llu\n",
 273		     (unsigned long long)bh->b_blocknr);
 274	} else
 275		rc = ocfs2_validate_gd_self(sb, bh, 1);
 276	if (!rc)
 277		rc = ocfs2_validate_gd_parent(sb, di, bh, 1);
 278
 279	return rc;
 280}
 281
 282static int ocfs2_validate_group_descriptor(struct super_block *sb,
 283					   struct buffer_head *bh)
 284{
 285	int rc;
 286	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 287
 288	trace_ocfs2_validate_group_descriptor(
 289					(unsigned long long)bh->b_blocknr);
 290
 291	BUG_ON(!buffer_uptodate(bh));
 292
 293	/*
 294	 * If the ecc fails, we return the error but otherwise
 295	 * leave the filesystem running.  We know any error is
 296	 * local to this block.
 297	 */
 298	rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
 299	if (rc)
 300		return rc;
 301
 302	/*
 303	 * Errors after here are fatal.
 304	 */
 305
 306	return ocfs2_validate_gd_self(sb, bh, 0);
 307}
 308
 309int ocfs2_read_group_descriptor(struct inode *inode, struct ocfs2_dinode *di,
 310				u64 gd_blkno, struct buffer_head **bh)
 311{
 312	int rc;
 313	struct buffer_head *tmp = *bh;
 314
 315	rc = ocfs2_read_block(INODE_CACHE(inode), gd_blkno, &tmp,
 316			      ocfs2_validate_group_descriptor);
 317	if (rc)
 318		goto out;
 319
 320	rc = ocfs2_validate_gd_parent(inode->i_sb, di, tmp, 0);
 321	if (rc) {
 322		brelse(tmp);
 323		goto out;
 324	}
 325
 326	/* If ocfs2_read_block() got us a new bh, pass it up. */
 327	if (!*bh)
 328		*bh = tmp;
 329
 330out:
 331	return rc;
 332}
 333
 334static void ocfs2_bg_discontig_add_extent(struct ocfs2_super *osb,
 335					  struct ocfs2_group_desc *bg,
 336					  struct ocfs2_chain_list *cl,
 337					  u64 p_blkno, unsigned int clusters)
 338{
 339	struct ocfs2_extent_list *el = &bg->bg_list;
 340	struct ocfs2_extent_rec *rec;
 341
 342	BUG_ON(!ocfs2_supports_discontig_bg(osb));
 343	if (!el->l_next_free_rec)
 344		el->l_count = cpu_to_le16(ocfs2_extent_recs_per_gd(osb->sb));
 345	rec = &el->l_recs[le16_to_cpu(el->l_next_free_rec)];
 346	rec->e_blkno = cpu_to_le64(p_blkno);
 347	rec->e_cpos = cpu_to_le32(le16_to_cpu(bg->bg_bits) /
 348				  le16_to_cpu(cl->cl_bpc));
 349	rec->e_leaf_clusters = cpu_to_le16(clusters);
 350	le16_add_cpu(&bg->bg_bits, clusters * le16_to_cpu(cl->cl_bpc));
 351	le16_add_cpu(&bg->bg_free_bits_count,
 352		     clusters * le16_to_cpu(cl->cl_bpc));
 353	le16_add_cpu(&el->l_next_free_rec, 1);
 354}
 355
 356static int ocfs2_block_group_fill(handle_t *handle,
 357				  struct inode *alloc_inode,
 358				  struct buffer_head *bg_bh,
 359				  u64 group_blkno,
 360				  unsigned int group_clusters,
 361				  u16 my_chain,
 362				  struct ocfs2_chain_list *cl)
 363{
 364	int status = 0;
 365	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 366	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 367	struct super_block * sb = alloc_inode->i_sb;
 368
 369	if (((unsigned long long) bg_bh->b_blocknr) != group_blkno) {
 370		status = ocfs2_error(alloc_inode->i_sb,
 371				     "group block (%llu) != b_blocknr (%llu)\n",
 372				     (unsigned long long)group_blkno,
 373				     (unsigned long long) bg_bh->b_blocknr);
 
 374		goto bail;
 375	}
 376
 377	status = ocfs2_journal_access_gd(handle,
 378					 INODE_CACHE(alloc_inode),
 379					 bg_bh,
 380					 OCFS2_JOURNAL_ACCESS_CREATE);
 381	if (status < 0) {
 382		mlog_errno(status);
 383		goto bail;
 384	}
 385
 386	memset(bg, 0, sb->s_blocksize);
 387	strcpy(bg->bg_signature, OCFS2_GROUP_DESC_SIGNATURE);
 388	bg->bg_generation = cpu_to_le32(osb->fs_generation);
 389	bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb, 1,
 390						osb->s_feature_incompat));
 391	bg->bg_chain = cpu_to_le16(my_chain);
 392	bg->bg_next_group = cl->cl_recs[my_chain].c_blkno;
 393	bg->bg_parent_dinode = cpu_to_le64(OCFS2_I(alloc_inode)->ip_blkno);
 394	bg->bg_blkno = cpu_to_le64(group_blkno);
 395	if (group_clusters == le16_to_cpu(cl->cl_cpg))
 396		bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
 397	else
 398		ocfs2_bg_discontig_add_extent(osb, bg, cl, group_blkno,
 399					      group_clusters);
 400
 401	/* set the 1st bit in the bitmap to account for the descriptor block */
 402	ocfs2_set_bit(0, (unsigned long *)bg->bg_bitmap);
 403	bg->bg_free_bits_count = cpu_to_le16(le16_to_cpu(bg->bg_bits) - 1);
 404
 405	ocfs2_journal_dirty(handle, bg_bh);
 406
 407	/* There is no need to zero out or otherwise initialize the
 408	 * other blocks in a group - All valid FS metadata in a block
 409	 * group stores the superblock fs_generation value at
 410	 * allocation time. */
 411
 412bail:
 413	if (status)
 414		mlog_errno(status);
 415	return status;
 416}
 417
 418static inline u16 ocfs2_find_smallest_chain(struct ocfs2_chain_list *cl)
 419{
 420	u16 curr, best;
 421
 422	best = curr = 0;
 423	while (curr < le16_to_cpu(cl->cl_count)) {
 424		if (le32_to_cpu(cl->cl_recs[best].c_total) >
 425		    le32_to_cpu(cl->cl_recs[curr].c_total))
 426			best = curr;
 427		curr++;
 428	}
 429	return best;
 430}
 431
 432static struct buffer_head *
 433ocfs2_block_group_alloc_contig(struct ocfs2_super *osb, handle_t *handle,
 434			       struct inode *alloc_inode,
 435			       struct ocfs2_alloc_context *ac,
 436			       struct ocfs2_chain_list *cl)
 437{
 438	int status;
 439	u32 bit_off, num_bits;
 440	u64 bg_blkno;
 441	struct buffer_head *bg_bh;
 442	unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
 443
 444	status = ocfs2_claim_clusters(handle, ac,
 445				      le16_to_cpu(cl->cl_cpg), &bit_off,
 446				      &num_bits);
 447	if (status < 0) {
 448		if (status != -ENOSPC)
 449			mlog_errno(status);
 450		goto bail;
 451	}
 452
 453	/* setup the group */
 454	bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 455	trace_ocfs2_block_group_alloc_contig(
 456	     (unsigned long long)bg_blkno, alloc_rec);
 457
 458	bg_bh = sb_getblk(osb->sb, bg_blkno);
 459	if (!bg_bh) {
 460		status = -ENOMEM;
 461		mlog_errno(status);
 462		goto bail;
 463	}
 464	ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
 465
 466	status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
 467					bg_blkno, num_bits, alloc_rec, cl);
 468	if (status < 0) {
 469		brelse(bg_bh);
 470		mlog_errno(status);
 471	}
 472
 473bail:
 474	return status ? ERR_PTR(status) : bg_bh;
 475}
 476
 477static int ocfs2_block_group_claim_bits(struct ocfs2_super *osb,
 478					handle_t *handle,
 479					struct ocfs2_alloc_context *ac,
 480					unsigned int min_bits,
 481					u32 *bit_off, u32 *num_bits)
 482{
 483	int status = 0;
 484
 485	while (min_bits) {
 486		status = ocfs2_claim_clusters(handle, ac, min_bits,
 487					      bit_off, num_bits);
 488		if (status != -ENOSPC)
 489			break;
 490
 491		min_bits >>= 1;
 492	}
 493
 494	return status;
 495}
 496
 497static int ocfs2_block_group_grow_discontig(handle_t *handle,
 498					    struct inode *alloc_inode,
 499					    struct buffer_head *bg_bh,
 500					    struct ocfs2_alloc_context *ac,
 501					    struct ocfs2_chain_list *cl,
 502					    unsigned int min_bits)
 503{
 504	int status;
 505	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 506	struct ocfs2_group_desc *bg =
 507		(struct ocfs2_group_desc *)bg_bh->b_data;
 508	unsigned int needed = le16_to_cpu(cl->cl_cpg) -
 509			 le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
 510	u32 p_cpos, clusters;
 511	u64 p_blkno;
 512	struct ocfs2_extent_list *el = &bg->bg_list;
 513
 514	status = ocfs2_journal_access_gd(handle,
 515					 INODE_CACHE(alloc_inode),
 516					 bg_bh,
 517					 OCFS2_JOURNAL_ACCESS_CREATE);
 518	if (status < 0) {
 519		mlog_errno(status);
 520		goto bail;
 521	}
 522
 523	while ((needed > 0) && (le16_to_cpu(el->l_next_free_rec) <
 524				le16_to_cpu(el->l_count))) {
 525		if (min_bits > needed)
 526			min_bits = needed;
 527		status = ocfs2_block_group_claim_bits(osb, handle, ac,
 528						      min_bits, &p_cpos,
 529						      &clusters);
 530		if (status < 0) {
 531			if (status != -ENOSPC)
 532				mlog_errno(status);
 533			goto bail;
 534		}
 535		p_blkno = ocfs2_clusters_to_blocks(osb->sb, p_cpos);
 536		ocfs2_bg_discontig_add_extent(osb, bg, cl, p_blkno,
 537					      clusters);
 538
 539		min_bits = clusters;
 540		needed = le16_to_cpu(cl->cl_cpg) -
 541			 le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
 542	}
 543
 544	if (needed > 0) {
 545		/*
 546		 * We have used up all the extent rec but can't fill up
 547		 * the cpg. So bail out.
 548		 */
 549		status = -ENOSPC;
 550		goto bail;
 551	}
 552
 553	ocfs2_journal_dirty(handle, bg_bh);
 554
 555bail:
 556	return status;
 557}
 558
 559static void ocfs2_bg_alloc_cleanup(handle_t *handle,
 560				   struct ocfs2_alloc_context *cluster_ac,
 561				   struct inode *alloc_inode,
 562				   struct buffer_head *bg_bh)
 563{
 564	int i, ret;
 565	struct ocfs2_group_desc *bg;
 566	struct ocfs2_extent_list *el;
 567	struct ocfs2_extent_rec *rec;
 568
 569	if (!bg_bh)
 570		return;
 571
 572	bg = (struct ocfs2_group_desc *)bg_bh->b_data;
 573	el = &bg->bg_list;
 574	for (i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
 575		rec = &el->l_recs[i];
 576		ret = ocfs2_free_clusters(handle, cluster_ac->ac_inode,
 577					  cluster_ac->ac_bh,
 578					  le64_to_cpu(rec->e_blkno),
 579					  le16_to_cpu(rec->e_leaf_clusters));
 580		if (ret)
 581			mlog_errno(ret);
 582		/* Try all the clusters to free */
 583	}
 584
 585	ocfs2_remove_from_cache(INODE_CACHE(alloc_inode), bg_bh);
 586	brelse(bg_bh);
 587}
 588
 589static struct buffer_head *
 590ocfs2_block_group_alloc_discontig(handle_t *handle,
 591				  struct inode *alloc_inode,
 592				  struct ocfs2_alloc_context *ac,
 593				  struct ocfs2_chain_list *cl)
 594{
 595	int status;
 596	u32 bit_off, num_bits;
 597	u64 bg_blkno;
 598	unsigned int min_bits = le16_to_cpu(cl->cl_cpg) >> 1;
 599	struct buffer_head *bg_bh = NULL;
 600	unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
 601	struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 602
 603	if (!ocfs2_supports_discontig_bg(osb)) {
 604		status = -ENOSPC;
 605		goto bail;
 606	}
 607
 608	status = ocfs2_extend_trans(handle,
 609				    ocfs2_calc_bg_discontig_credits(osb->sb));
 610	if (status) {
 611		mlog_errno(status);
 612		goto bail;
 613	}
 614
 615	/*
 616	 * We're going to be grabbing from multiple cluster groups.
 617	 * We don't have enough credits to relink them all, and the
 618	 * cluster groups will be staying in cache for the duration of
 619	 * this operation.
 620	 */
 621	ac->ac_disable_chain_relink = 1;
 622
 623	/* Claim the first region */
 624	status = ocfs2_block_group_claim_bits(osb, handle, ac, min_bits,
 625					      &bit_off, &num_bits);
 626	if (status < 0) {
 627		if (status != -ENOSPC)
 628			mlog_errno(status);
 629		goto bail;
 630	}
 631	min_bits = num_bits;
 632
 633	/* setup the group */
 634	bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 635	trace_ocfs2_block_group_alloc_discontig(
 636				(unsigned long long)bg_blkno, alloc_rec);
 637
 638	bg_bh = sb_getblk(osb->sb, bg_blkno);
 639	if (!bg_bh) {
 640		status = -ENOMEM;
 641		mlog_errno(status);
 642		goto bail;
 643	}
 644	ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
 645
 646	status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
 647					bg_blkno, num_bits, alloc_rec, cl);
 648	if (status < 0) {
 649		mlog_errno(status);
 650		goto bail;
 651	}
 652
 653	status = ocfs2_block_group_grow_discontig(handle, alloc_inode,
 654						  bg_bh, ac, cl, min_bits);
 655	if (status)
 656		mlog_errno(status);
 657
 658bail:
 659	if (status)
 660		ocfs2_bg_alloc_cleanup(handle, ac, alloc_inode, bg_bh);
 661	return status ? ERR_PTR(status) : bg_bh;
 662}
 663
 664/*
 665 * We expect the block group allocator to already be locked.
 666 */
 667static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
 668				   struct inode *alloc_inode,
 669				   struct buffer_head *bh,
 670				   u64 max_block,
 671				   u64 *last_alloc_group,
 672				   int flags)
 673{
 674	int status, credits;
 675	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) bh->b_data;
 676	struct ocfs2_chain_list *cl;
 677	struct ocfs2_alloc_context *ac = NULL;
 678	handle_t *handle = NULL;
 679	u16 alloc_rec;
 680	struct buffer_head *bg_bh = NULL;
 681	struct ocfs2_group_desc *bg;
 682
 683	BUG_ON(ocfs2_is_cluster_bitmap(alloc_inode));
 684
 685	cl = &fe->id2.i_chain;
 686	status = ocfs2_reserve_clusters_with_limit(osb,
 687						   le16_to_cpu(cl->cl_cpg),
 688						   max_block, flags, &ac);
 689	if (status < 0) {
 690		if (status != -ENOSPC)
 691			mlog_errno(status);
 692		goto bail;
 693	}
 694
 695	credits = ocfs2_calc_group_alloc_credits(osb->sb,
 696						 le16_to_cpu(cl->cl_cpg));
 697	handle = ocfs2_start_trans(osb, credits);
 698	if (IS_ERR(handle)) {
 699		status = PTR_ERR(handle);
 700		handle = NULL;
 701		mlog_errno(status);
 702		goto bail;
 703	}
 704
 705	if (last_alloc_group && *last_alloc_group != 0) {
 706		trace_ocfs2_block_group_alloc(
 707				(unsigned long long)*last_alloc_group);
 708		ac->ac_last_group = *last_alloc_group;
 709	}
 710
 711	bg_bh = ocfs2_block_group_alloc_contig(osb, handle, alloc_inode,
 712					       ac, cl);
 713	if (IS_ERR(bg_bh) && (PTR_ERR(bg_bh) == -ENOSPC))
 714		bg_bh = ocfs2_block_group_alloc_discontig(handle,
 715							  alloc_inode,
 716							  ac, cl);
 717	if (IS_ERR(bg_bh)) {
 718		status = PTR_ERR(bg_bh);
 719		bg_bh = NULL;
 720		if (status != -ENOSPC)
 721			mlog_errno(status);
 722		goto bail;
 723	}
 724	bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 725
 726	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
 727					 bh, OCFS2_JOURNAL_ACCESS_WRITE);
 728	if (status < 0) {
 729		mlog_errno(status);
 730		goto bail;
 731	}
 732
 733	alloc_rec = le16_to_cpu(bg->bg_chain);
 734	le32_add_cpu(&cl->cl_recs[alloc_rec].c_free,
 735		     le16_to_cpu(bg->bg_free_bits_count));
 736	le32_add_cpu(&cl->cl_recs[alloc_rec].c_total,
 737		     le16_to_cpu(bg->bg_bits));
 738	cl->cl_recs[alloc_rec].c_blkno = bg->bg_blkno;
 739	if (le16_to_cpu(cl->cl_next_free_rec) < le16_to_cpu(cl->cl_count))
 740		le16_add_cpu(&cl->cl_next_free_rec, 1);
 741
 742	le32_add_cpu(&fe->id1.bitmap1.i_used, le16_to_cpu(bg->bg_bits) -
 743					le16_to_cpu(bg->bg_free_bits_count));
 744	le32_add_cpu(&fe->id1.bitmap1.i_total, le16_to_cpu(bg->bg_bits));
 745	le32_add_cpu(&fe->i_clusters, le16_to_cpu(cl->cl_cpg));
 746
 747	ocfs2_journal_dirty(handle, bh);
 748
 749	spin_lock(&OCFS2_I(alloc_inode)->ip_lock);
 750	OCFS2_I(alloc_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
 751	fe->i_size = cpu_to_le64(ocfs2_clusters_to_bytes(alloc_inode->i_sb,
 752					     le32_to_cpu(fe->i_clusters)));
 753	spin_unlock(&OCFS2_I(alloc_inode)->ip_lock);
 754	i_size_write(alloc_inode, le64_to_cpu(fe->i_size));
 755	alloc_inode->i_blocks = ocfs2_inode_sector_count(alloc_inode);
 756	ocfs2_update_inode_fsync_trans(handle, alloc_inode, 0);
 757
 758	status = 0;
 759
 760	/* save the new last alloc group so that the caller can cache it. */
 761	if (last_alloc_group)
 762		*last_alloc_group = ac->ac_last_group;
 763
 764bail:
 765	if (handle)
 766		ocfs2_commit_trans(osb, handle);
 767
 768	if (ac)
 769		ocfs2_free_alloc_context(ac);
 770
 771	brelse(bg_bh);
 772
 773	if (status)
 774		mlog_errno(status);
 775	return status;
 776}
 777
 778static int ocfs2_reserve_suballoc_bits(struct ocfs2_super *osb,
 779				       struct ocfs2_alloc_context *ac,
 780				       int type,
 781				       u32 slot,
 782				       u64 *last_alloc_group,
 783				       int flags)
 784{
 785	int status;
 786	u32 bits_wanted = ac->ac_bits_wanted;
 787	struct inode *alloc_inode;
 788	struct buffer_head *bh = NULL;
 789	struct ocfs2_dinode *fe;
 790	u32 free_bits;
 791
 792	alloc_inode = ocfs2_get_system_file_inode(osb, type, slot);
 793	if (!alloc_inode) {
 794		mlog_errno(-EINVAL);
 795		return -EINVAL;
 796	}
 797
 798	inode_lock(alloc_inode);
 799
 800	status = ocfs2_inode_lock(alloc_inode, &bh, 1);
 801	if (status < 0) {
 802		inode_unlock(alloc_inode);
 803		iput(alloc_inode);
 804
 805		mlog_errno(status);
 806		return status;
 807	}
 808
 809	ac->ac_inode = alloc_inode;
 810	ac->ac_alloc_slot = slot;
 811
 812	fe = (struct ocfs2_dinode *) bh->b_data;
 813
 814	/* The bh was validated by the inode read inside
 815	 * ocfs2_inode_lock().  Any corruption is a code bug. */
 816	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
 817
 818	if (!(fe->i_flags & cpu_to_le32(OCFS2_CHAIN_FL))) {
 819		status = ocfs2_error(alloc_inode->i_sb,
 820				     "Invalid chain allocator %llu\n",
 821				     (unsigned long long)le64_to_cpu(fe->i_blkno));
 822		goto bail;
 823	}
 824
 825	free_bits = le32_to_cpu(fe->id1.bitmap1.i_total) -
 826		le32_to_cpu(fe->id1.bitmap1.i_used);
 827
 828	if (bits_wanted > free_bits) {
 829		/* cluster bitmap never grows */
 830		if (ocfs2_is_cluster_bitmap(alloc_inode)) {
 831			trace_ocfs2_reserve_suballoc_bits_nospc(bits_wanted,
 832								free_bits);
 833			status = -ENOSPC;
 834			goto bail;
 835		}
 836
 837		if (!(flags & ALLOC_NEW_GROUP)) {
 838			trace_ocfs2_reserve_suballoc_bits_no_new_group(
 839						slot, bits_wanted, free_bits);
 840			status = -ENOSPC;
 841			goto bail;
 842		}
 843
 844		status = ocfs2_block_group_alloc(osb, alloc_inode, bh,
 845						 ac->ac_max_block,
 846						 last_alloc_group, flags);
 847		if (status < 0) {
 848			if (status != -ENOSPC)
 849				mlog_errno(status);
 850			goto bail;
 851		}
 852		atomic_inc(&osb->alloc_stats.bg_extends);
 853
 854		/* You should never ask for this much metadata */
 855		BUG_ON(bits_wanted >
 856		       (le32_to_cpu(fe->id1.bitmap1.i_total)
 857			- le32_to_cpu(fe->id1.bitmap1.i_used)));
 858	}
 859
 860	get_bh(bh);
 861	ac->ac_bh = bh;
 862bail:
 863	brelse(bh);
 864
 865	if (status)
 866		mlog_errno(status);
 867	return status;
 868}
 869
 870static void ocfs2_init_inode_steal_slot(struct ocfs2_super *osb)
 871{
 872	spin_lock(&osb->osb_lock);
 873	osb->s_inode_steal_slot = OCFS2_INVALID_SLOT;
 874	spin_unlock(&osb->osb_lock);
 875	atomic_set(&osb->s_num_inodes_stolen, 0);
 876}
 877
 878static void ocfs2_init_meta_steal_slot(struct ocfs2_super *osb)
 879{
 880	spin_lock(&osb->osb_lock);
 881	osb->s_meta_steal_slot = OCFS2_INVALID_SLOT;
 882	spin_unlock(&osb->osb_lock);
 883	atomic_set(&osb->s_num_meta_stolen, 0);
 884}
 885
 886void ocfs2_init_steal_slots(struct ocfs2_super *osb)
 887{
 888	ocfs2_init_inode_steal_slot(osb);
 889	ocfs2_init_meta_steal_slot(osb);
 890}
 891
 892static void __ocfs2_set_steal_slot(struct ocfs2_super *osb, int slot, int type)
 893{
 894	spin_lock(&osb->osb_lock);
 895	if (type == INODE_ALLOC_SYSTEM_INODE)
 896		osb->s_inode_steal_slot = slot;
 897	else if (type == EXTENT_ALLOC_SYSTEM_INODE)
 898		osb->s_meta_steal_slot = slot;
 899	spin_unlock(&osb->osb_lock);
 900}
 901
 902static int __ocfs2_get_steal_slot(struct ocfs2_super *osb, int type)
 903{
 904	int slot = OCFS2_INVALID_SLOT;
 905
 906	spin_lock(&osb->osb_lock);
 907	if (type == INODE_ALLOC_SYSTEM_INODE)
 908		slot = osb->s_inode_steal_slot;
 909	else if (type == EXTENT_ALLOC_SYSTEM_INODE)
 910		slot = osb->s_meta_steal_slot;
 911	spin_unlock(&osb->osb_lock);
 912
 913	return slot;
 914}
 915
 916static int ocfs2_get_inode_steal_slot(struct ocfs2_super *osb)
 917{
 918	return __ocfs2_get_steal_slot(osb, INODE_ALLOC_SYSTEM_INODE);
 919}
 920
 921static int ocfs2_get_meta_steal_slot(struct ocfs2_super *osb)
 922{
 923	return __ocfs2_get_steal_slot(osb, EXTENT_ALLOC_SYSTEM_INODE);
 924}
 925
 926static int ocfs2_steal_resource(struct ocfs2_super *osb,
 927				struct ocfs2_alloc_context *ac,
 928				int type)
 929{
 930	int i, status = -ENOSPC;
 931	int slot = __ocfs2_get_steal_slot(osb, type);
 932
 933	/* Start to steal resource from the first slot after ours. */
 934	if (slot == OCFS2_INVALID_SLOT)
 935		slot = osb->slot_num + 1;
 936
 937	for (i = 0; i < osb->max_slots; i++, slot++) {
 938		if (slot == osb->max_slots)
 939			slot = 0;
 940
 941		if (slot == osb->slot_num)
 942			continue;
 943
 944		status = ocfs2_reserve_suballoc_bits(osb, ac,
 945						     type,
 946						     (u32)slot, NULL,
 947						     NOT_ALLOC_NEW_GROUP);
 948		if (status >= 0) {
 949			__ocfs2_set_steal_slot(osb, slot, type);
 950			break;
 951		}
 952
 953		ocfs2_free_ac_resource(ac);
 954	}
 955
 956	return status;
 957}
 958
 959static int ocfs2_steal_inode(struct ocfs2_super *osb,
 960			     struct ocfs2_alloc_context *ac)
 961{
 962	return ocfs2_steal_resource(osb, ac, INODE_ALLOC_SYSTEM_INODE);
 963}
 964
 965static int ocfs2_steal_meta(struct ocfs2_super *osb,
 966			    struct ocfs2_alloc_context *ac)
 967{
 968	return ocfs2_steal_resource(osb, ac, EXTENT_ALLOC_SYSTEM_INODE);
 969}
 970
 971int ocfs2_reserve_new_metadata_blocks(struct ocfs2_super *osb,
 972				      int blocks,
 973				      struct ocfs2_alloc_context **ac)
 974{
 975	int status;
 976	int slot = ocfs2_get_meta_steal_slot(osb);
 977
 978	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 979	if (!(*ac)) {
 980		status = -ENOMEM;
 981		mlog_errno(status);
 982		goto bail;
 983	}
 984
 985	(*ac)->ac_bits_wanted = blocks;
 986	(*ac)->ac_which = OCFS2_AC_USE_META;
 987	(*ac)->ac_group_search = ocfs2_block_group_search;
 988
 989	if (slot != OCFS2_INVALID_SLOT &&
 990		atomic_read(&osb->s_num_meta_stolen) < OCFS2_MAX_TO_STEAL)
 991		goto extent_steal;
 992
 993	atomic_set(&osb->s_num_meta_stolen, 0);
 994	status = ocfs2_reserve_suballoc_bits(osb, (*ac),
 995					     EXTENT_ALLOC_SYSTEM_INODE,
 996					     (u32)osb->slot_num, NULL,
 997					     ALLOC_GROUPS_FROM_GLOBAL|ALLOC_NEW_GROUP);
 998
 999
1000	if (status >= 0) {
1001		status = 0;
1002		if (slot != OCFS2_INVALID_SLOT)
1003			ocfs2_init_meta_steal_slot(osb);
1004		goto bail;
1005	} else if (status < 0 && status != -ENOSPC) {
1006		mlog_errno(status);
1007		goto bail;
1008	}
1009
1010	ocfs2_free_ac_resource(*ac);
1011
1012extent_steal:
1013	status = ocfs2_steal_meta(osb, *ac);
1014	atomic_inc(&osb->s_num_meta_stolen);
1015	if (status < 0) {
1016		if (status != -ENOSPC)
1017			mlog_errno(status);
1018		goto bail;
1019	}
1020
1021	status = 0;
1022bail:
1023	if ((status < 0) && *ac) {
1024		ocfs2_free_alloc_context(*ac);
1025		*ac = NULL;
1026	}
1027
1028	if (status)
1029		mlog_errno(status);
1030	return status;
1031}
1032
1033int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
1034			       struct ocfs2_extent_list *root_el,
1035			       struct ocfs2_alloc_context **ac)
1036{
1037	return ocfs2_reserve_new_metadata_blocks(osb,
1038					ocfs2_extend_meta_needed(root_el),
1039					ac);
1040}
1041
1042int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
1043			    struct ocfs2_alloc_context **ac)
1044{
1045	int status;
1046	int slot = ocfs2_get_inode_steal_slot(osb);
1047	u64 alloc_group;
1048
1049	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1050	if (!(*ac)) {
1051		status = -ENOMEM;
1052		mlog_errno(status);
1053		goto bail;
1054	}
1055
1056	(*ac)->ac_bits_wanted = 1;
1057	(*ac)->ac_which = OCFS2_AC_USE_INODE;
1058
1059	(*ac)->ac_group_search = ocfs2_block_group_search;
1060
1061	/*
1062	 * stat(2) can't handle i_ino > 32bits, so we tell the
1063	 * lower levels not to allocate us a block group past that
1064	 * limit.  The 'inode64' mount option avoids this behavior.
1065	 */
1066	if (!(osb->s_mount_opt & OCFS2_MOUNT_INODE64))
1067		(*ac)->ac_max_block = (u32)~0U;
1068
1069	/*
1070	 * slot is set when we successfully steal inode from other nodes.
1071	 * It is reset in 3 places:
1072	 * 1. when we flush the truncate log
1073	 * 2. when we complete local alloc recovery.
1074	 * 3. when we successfully allocate from our own slot.
1075	 * After it is set, we will go on stealing inodes until we find the
1076	 * need to check our slots to see whether there is some space for us.
1077	 */
1078	if (slot != OCFS2_INVALID_SLOT &&
1079	    atomic_read(&osb->s_num_inodes_stolen) < OCFS2_MAX_TO_STEAL)
1080		goto inode_steal;
1081
1082	atomic_set(&osb->s_num_inodes_stolen, 0);
1083	alloc_group = osb->osb_inode_alloc_group;
1084	status = ocfs2_reserve_suballoc_bits(osb, *ac,
1085					     INODE_ALLOC_SYSTEM_INODE,
1086					     (u32)osb->slot_num,
1087					     &alloc_group,
1088					     ALLOC_NEW_GROUP |
1089					     ALLOC_GROUPS_FROM_GLOBAL);
1090	if (status >= 0) {
1091		status = 0;
1092
1093		spin_lock(&osb->osb_lock);
1094		osb->osb_inode_alloc_group = alloc_group;
1095		spin_unlock(&osb->osb_lock);
1096		trace_ocfs2_reserve_new_inode_new_group(
1097			(unsigned long long)alloc_group);
1098
1099		/*
1100		 * Some inodes must be freed by us, so try to allocate
1101		 * from our own next time.
1102		 */
1103		if (slot != OCFS2_INVALID_SLOT)
1104			ocfs2_init_inode_steal_slot(osb);
1105		goto bail;
1106	} else if (status < 0 && status != -ENOSPC) {
1107		mlog_errno(status);
1108		goto bail;
1109	}
1110
1111	ocfs2_free_ac_resource(*ac);
1112
1113inode_steal:
1114	status = ocfs2_steal_inode(osb, *ac);
1115	atomic_inc(&osb->s_num_inodes_stolen);
1116	if (status < 0) {
1117		if (status != -ENOSPC)
1118			mlog_errno(status);
1119		goto bail;
1120	}
1121
1122	status = 0;
1123bail:
1124	if ((status < 0) && *ac) {
1125		ocfs2_free_alloc_context(*ac);
1126		*ac = NULL;
1127	}
1128
1129	if (status)
1130		mlog_errno(status);
1131	return status;
1132}
1133
1134/* local alloc code has to do the same thing, so rather than do this
1135 * twice.. */
1136int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
1137				      struct ocfs2_alloc_context *ac)
1138{
1139	int status;
1140
1141	ac->ac_which = OCFS2_AC_USE_MAIN;
1142	ac->ac_group_search = ocfs2_cluster_group_search;
1143
1144	status = ocfs2_reserve_suballoc_bits(osb, ac,
1145					     GLOBAL_BITMAP_SYSTEM_INODE,
1146					     OCFS2_INVALID_SLOT, NULL,
1147					     ALLOC_NEW_GROUP);
1148	if (status < 0 && status != -ENOSPC)
1149		mlog_errno(status);
 
 
1150
 
1151	return status;
1152}
1153
1154/* Callers don't need to care which bitmap (local alloc or main) to
1155 * use so we figure it out for them, but unfortunately this clutters
1156 * things a bit. */
1157static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
1158					     u32 bits_wanted, u64 max_block,
1159					     int flags,
1160					     struct ocfs2_alloc_context **ac)
1161{
1162	int status, ret = 0;
1163	int retried = 0;
1164
1165	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1166	if (!(*ac)) {
1167		status = -ENOMEM;
1168		mlog_errno(status);
1169		goto bail;
1170	}
1171
1172	(*ac)->ac_bits_wanted = bits_wanted;
1173	(*ac)->ac_max_block = max_block;
1174
1175	status = -ENOSPC;
1176	if (!(flags & ALLOC_GROUPS_FROM_GLOBAL) &&
1177	    ocfs2_alloc_should_use_local(osb, bits_wanted)) {
1178		status = ocfs2_reserve_local_alloc_bits(osb,
1179							bits_wanted,
1180							*ac);
1181		if ((status < 0) && (status != -ENOSPC)) {
1182			mlog_errno(status);
1183			goto bail;
1184		}
1185	}
1186
1187	if (status == -ENOSPC) {
1188retry:
1189		status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
1190		/* Retry if there is sufficient space cached in truncate log */
1191		if (status == -ENOSPC && !retried) {
1192			retried = 1;
1193			ocfs2_inode_unlock((*ac)->ac_inode, 1);
1194			inode_unlock((*ac)->ac_inode);
1195
1196			ret = ocfs2_try_to_free_truncate_log(osb, bits_wanted);
1197			if (ret == 1) {
1198				iput((*ac)->ac_inode);
1199				(*ac)->ac_inode = NULL;
1200				goto retry;
1201			}
1202
1203			if (ret < 0)
1204				mlog_errno(ret);
1205
1206			inode_lock((*ac)->ac_inode);
1207			ret = ocfs2_inode_lock((*ac)->ac_inode, NULL, 1);
1208			if (ret < 0) {
1209				mlog_errno(ret);
1210				inode_unlock((*ac)->ac_inode);
1211				iput((*ac)->ac_inode);
1212				(*ac)->ac_inode = NULL;
1213				goto bail;
1214			}
1215		}
1216		if (status < 0) {
1217			if (status != -ENOSPC)
1218				mlog_errno(status);
1219			goto bail;
1220		}
1221	}
1222
1223	status = 0;
1224bail:
1225	if ((status < 0) && *ac) {
1226		ocfs2_free_alloc_context(*ac);
1227		*ac = NULL;
1228	}
1229
1230	if (status)
1231		mlog_errno(status);
1232	return status;
1233}
1234
1235int ocfs2_reserve_clusters(struct ocfs2_super *osb,
1236			   u32 bits_wanted,
1237			   struct ocfs2_alloc_context **ac)
1238{
1239	return ocfs2_reserve_clusters_with_limit(osb, bits_wanted, 0,
1240						 ALLOC_NEW_GROUP, ac);
1241}
1242
1243/*
1244 * More or less lifted from ext3. I'll leave their description below:
1245 *
1246 * "For ext3 allocations, we must not reuse any blocks which are
1247 * allocated in the bitmap buffer's "last committed data" copy.  This
1248 * prevents deletes from freeing up the page for reuse until we have
1249 * committed the delete transaction.
1250 *
1251 * If we didn't do this, then deleting something and reallocating it as
1252 * data would allow the old block to be overwritten before the
1253 * transaction committed (because we force data to disk before commit).
1254 * This would lead to corruption if we crashed between overwriting the
1255 * data and committing the delete.
1256 *
1257 * @@@ We may want to make this allocation behaviour conditional on
1258 * data-writes at some point, and disable it for metadata allocations or
1259 * sync-data inodes."
1260 *
1261 * Note: OCFS2 already does this differently for metadata vs data
1262 * allocations, as those bitmaps are separate and undo access is never
1263 * called on a metadata group descriptor.
1264 */
1265static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
1266					 int nr)
1267{
1268	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1269	int ret;
1270
1271	if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
1272		return 0;
1273
1274	if (!buffer_jbd(bg_bh))
1275		return 1;
1276
1277	jbd_lock_bh_state(bg_bh);
1278	bg = (struct ocfs2_group_desc *) bh2jh(bg_bh)->b_committed_data;
1279	if (bg)
1280		ret = !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
1281	else
1282		ret = 1;
1283	jbd_unlock_bh_state(bg_bh);
1284
1285	return ret;
1286}
1287
1288static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
1289					     struct buffer_head *bg_bh,
1290					     unsigned int bits_wanted,
1291					     unsigned int total_bits,
1292					     struct ocfs2_suballoc_result *res)
1293{
1294	void *bitmap;
1295	u16 best_offset, best_size;
1296	int offset, start, found, status = 0;
1297	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1298
1299	/* Callers got this descriptor from
1300	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1301	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1302
1303	found = start = best_offset = best_size = 0;
1304	bitmap = bg->bg_bitmap;
1305
1306	while((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) != -1) {
1307		if (offset == total_bits)
1308			break;
1309
1310		if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
1311			/* We found a zero, but we can't use it as it
1312			 * hasn't been put to disk yet! */
1313			found = 0;
1314			start = offset + 1;
1315		} else if (offset == start) {
1316			/* we found a zero */
1317			found++;
1318			/* move start to the next bit to test */
1319			start++;
1320		} else {
1321			/* got a zero after some ones */
1322			found = 1;
1323			start = offset + 1;
1324		}
1325		if (found > best_size) {
1326			best_size = found;
1327			best_offset = start - found;
1328		}
1329		/* we got everything we needed */
1330		if (found == bits_wanted) {
1331			/* mlog(0, "Found it all!\n"); */
1332			break;
1333		}
1334	}
1335
1336	if (best_size) {
1337		res->sr_bit_offset = best_offset;
1338		res->sr_bits = best_size;
1339	} else {
1340		status = -ENOSPC;
1341		/* No error log here -- see the comment above
1342		 * ocfs2_test_bg_bit_allocatable */
1343	}
1344
1345	return status;
1346}
1347
1348int ocfs2_block_group_set_bits(handle_t *handle,
1349					     struct inode *alloc_inode,
1350					     struct ocfs2_group_desc *bg,
1351					     struct buffer_head *group_bh,
1352					     unsigned int bit_off,
1353					     unsigned int num_bits)
1354{
1355	int status;
1356	void *bitmap = bg->bg_bitmap;
1357	int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1358
1359	/* All callers get the descriptor via
1360	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1361	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1362	BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
1363
1364	trace_ocfs2_block_group_set_bits(bit_off, num_bits);
1365
1366	if (ocfs2_is_cluster_bitmap(alloc_inode))
1367		journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1368
1369	status = ocfs2_journal_access_gd(handle,
1370					 INODE_CACHE(alloc_inode),
1371					 group_bh,
1372					 journal_type);
1373	if (status < 0) {
1374		mlog_errno(status);
1375		goto bail;
1376	}
1377
1378	le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
1379	if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
1380		return ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit count %u but claims %u are freed. num_bits %d\n",
1381				   (unsigned long long)le64_to_cpu(bg->bg_blkno),
1382				   le16_to_cpu(bg->bg_bits),
1383				   le16_to_cpu(bg->bg_free_bits_count),
1384				   num_bits);
 
1385	}
1386	while(num_bits--)
1387		ocfs2_set_bit(bit_off++, bitmap);
1388
1389	ocfs2_journal_dirty(handle, group_bh);
1390
1391bail:
1392	return status;
1393}
1394
1395/* find the one with the most empty bits */
1396static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
1397{
1398	u16 curr, best;
1399
1400	BUG_ON(!cl->cl_next_free_rec);
1401
1402	best = curr = 0;
1403	while (curr < le16_to_cpu(cl->cl_next_free_rec)) {
1404		if (le32_to_cpu(cl->cl_recs[curr].c_free) >
1405		    le32_to_cpu(cl->cl_recs[best].c_free))
1406			best = curr;
1407		curr++;
1408	}
1409
1410	BUG_ON(best >= le16_to_cpu(cl->cl_next_free_rec));
1411	return best;
1412}
1413
1414static int ocfs2_relink_block_group(handle_t *handle,
1415				    struct inode *alloc_inode,
1416				    struct buffer_head *fe_bh,
1417				    struct buffer_head *bg_bh,
1418				    struct buffer_head *prev_bg_bh,
1419				    u16 chain)
1420{
1421	int status;
1422	/* there is a really tiny chance the journal calls could fail,
1423	 * but we wouldn't want inconsistent blocks in *any* case. */
1424	u64 bg_ptr, prev_bg_ptr;
1425	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
1426	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1427	struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
1428
1429	/* The caller got these descriptors from
1430	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1431	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1432	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(prev_bg));
1433
1434	trace_ocfs2_relink_block_group(
1435		(unsigned long long)le64_to_cpu(fe->i_blkno), chain,
1436		(unsigned long long)le64_to_cpu(bg->bg_blkno),
1437		(unsigned long long)le64_to_cpu(prev_bg->bg_blkno));
1438
1439	bg_ptr = le64_to_cpu(bg->bg_next_group);
1440	prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
1441
1442	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1443					 prev_bg_bh,
1444					 OCFS2_JOURNAL_ACCESS_WRITE);
1445	if (status < 0)
1446		goto out;
1447
1448	prev_bg->bg_next_group = bg->bg_next_group;
1449	ocfs2_journal_dirty(handle, prev_bg_bh);
1450
1451	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1452					 bg_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1453	if (status < 0)
1454		goto out_rollback_prev_bg;
1455
1456	bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
1457	ocfs2_journal_dirty(handle, bg_bh);
1458
1459	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
1460					 fe_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1461	if (status < 0)
1462		goto out_rollback_bg;
1463
1464	fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
1465	ocfs2_journal_dirty(handle, fe_bh);
1466
1467out:
1468	if (status < 0)
1469		mlog_errno(status);
1470	return status;
1471
1472out_rollback_bg:
1473	bg->bg_next_group = cpu_to_le64(bg_ptr);
1474out_rollback_prev_bg:
1475	prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
1476	goto out;
1477}
1478
1479static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
1480						     u32 wanted)
1481{
1482	return le16_to_cpu(bg->bg_free_bits_count) > wanted;
1483}
1484
1485/* return 0 on success, -ENOSPC to keep searching and any other < 0
1486 * value on error. */
1487static int ocfs2_cluster_group_search(struct inode *inode,
1488				      struct buffer_head *group_bh,
1489				      u32 bits_wanted, u32 min_bits,
1490				      u64 max_block,
1491				      struct ocfs2_suballoc_result *res)
1492{
1493	int search = -ENOSPC;
1494	int ret;
1495	u64 blkoff;
1496	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
1497	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1498	unsigned int max_bits, gd_cluster_off;
1499
1500	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1501
1502	if (gd->bg_free_bits_count) {
1503		max_bits = le16_to_cpu(gd->bg_bits);
1504
1505		/* Tail groups in cluster bitmaps which aren't cpg
1506		 * aligned are prone to partial extension by a failed
1507		 * fs resize. If the file system resize never got to
1508		 * update the dinode cluster count, then we don't want
1509		 * to trust any clusters past it, regardless of what
1510		 * the group descriptor says. */
1511		gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
1512							  le64_to_cpu(gd->bg_blkno));
1513		if ((gd_cluster_off + max_bits) >
1514		    OCFS2_I(inode)->ip_clusters) {
1515			max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
1516			trace_ocfs2_cluster_group_search_wrong_max_bits(
1517				(unsigned long long)le64_to_cpu(gd->bg_blkno),
1518				le16_to_cpu(gd->bg_bits),
1519				OCFS2_I(inode)->ip_clusters, max_bits);
1520		}
1521
1522		ret = ocfs2_block_group_find_clear_bits(osb,
1523							group_bh, bits_wanted,
1524							max_bits, res);
1525		if (ret)
1526			return ret;
1527
1528		if (max_block) {
1529			blkoff = ocfs2_clusters_to_blocks(inode->i_sb,
1530							  gd_cluster_off +
1531							  res->sr_bit_offset +
1532							  res->sr_bits);
1533			trace_ocfs2_cluster_group_search_max_block(
1534				(unsigned long long)blkoff,
1535				(unsigned long long)max_block);
1536			if (blkoff > max_block)
1537				return -ENOSPC;
1538		}
1539
1540		/* ocfs2_block_group_find_clear_bits() might
1541		 * return success, but we still want to return
1542		 * -ENOSPC unless it found the minimum number
1543		 * of bits. */
1544		if (min_bits <= res->sr_bits)
1545			search = 0; /* success */
1546		else if (res->sr_bits) {
1547			/*
1548			 * Don't show bits which we'll be returning
1549			 * for allocation to the local alloc bitmap.
1550			 */
1551			ocfs2_local_alloc_seen_free_bits(osb, res->sr_bits);
1552		}
1553	}
1554
1555	return search;
1556}
1557
1558static int ocfs2_block_group_search(struct inode *inode,
1559				    struct buffer_head *group_bh,
1560				    u32 bits_wanted, u32 min_bits,
1561				    u64 max_block,
1562				    struct ocfs2_suballoc_result *res)
1563{
1564	int ret = -ENOSPC;
1565	u64 blkoff;
1566	struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
1567
1568	BUG_ON(min_bits != 1);
1569	BUG_ON(ocfs2_is_cluster_bitmap(inode));
1570
1571	if (bg->bg_free_bits_count) {
1572		ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1573							group_bh, bits_wanted,
1574							le16_to_cpu(bg->bg_bits),
1575							res);
1576		if (!ret && max_block) {
1577			blkoff = le64_to_cpu(bg->bg_blkno) +
1578				res->sr_bit_offset + res->sr_bits;
1579			trace_ocfs2_block_group_search_max_block(
1580				(unsigned long long)blkoff,
1581				(unsigned long long)max_block);
1582			if (blkoff > max_block)
1583				ret = -ENOSPC;
1584		}
1585	}
1586
1587	return ret;
1588}
1589
1590int ocfs2_alloc_dinode_update_counts(struct inode *inode,
1591				       handle_t *handle,
1592				       struct buffer_head *di_bh,
1593				       u32 num_bits,
1594				       u16 chain)
1595{
1596	int ret;
1597	u32 tmp_used;
1598	struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1599	struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &di->id2.i_chain;
1600
1601	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
1602				      OCFS2_JOURNAL_ACCESS_WRITE);
1603	if (ret < 0) {
1604		mlog_errno(ret);
1605		goto out;
1606	}
1607
1608	tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1609	di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
1610	le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
1611	ocfs2_journal_dirty(handle, di_bh);
1612
1613out:
1614	return ret;
1615}
1616
1617void ocfs2_rollback_alloc_dinode_counts(struct inode *inode,
1618				       struct buffer_head *di_bh,
1619				       u32 num_bits,
1620				       u16 chain)
1621{
1622	u32 tmp_used;
1623	struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1624	struct ocfs2_chain_list *cl;
1625
1626	cl = (struct ocfs2_chain_list *)&di->id2.i_chain;
1627	tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1628	di->id1.bitmap1.i_used = cpu_to_le32(tmp_used - num_bits);
1629	le32_add_cpu(&cl->cl_recs[chain].c_free, num_bits);
1630}
1631
1632static int ocfs2_bg_discontig_fix_by_rec(struct ocfs2_suballoc_result *res,
1633					 struct ocfs2_extent_rec *rec,
1634					 struct ocfs2_chain_list *cl)
1635{
1636	unsigned int bpc = le16_to_cpu(cl->cl_bpc);
1637	unsigned int bitoff = le32_to_cpu(rec->e_cpos) * bpc;
1638	unsigned int bitcount = le16_to_cpu(rec->e_leaf_clusters) * bpc;
1639
1640	if (res->sr_bit_offset < bitoff)
1641		return 0;
1642	if (res->sr_bit_offset >= (bitoff + bitcount))
1643		return 0;
1644	res->sr_blkno = le64_to_cpu(rec->e_blkno) +
1645		(res->sr_bit_offset - bitoff);
1646	if ((res->sr_bit_offset + res->sr_bits) > (bitoff + bitcount))
1647		res->sr_bits = (bitoff + bitcount) - res->sr_bit_offset;
1648	return 1;
1649}
1650
1651static void ocfs2_bg_discontig_fix_result(struct ocfs2_alloc_context *ac,
1652					  struct ocfs2_group_desc *bg,
1653					  struct ocfs2_suballoc_result *res)
1654{
1655	int i;
1656	u64 bg_blkno = res->sr_bg_blkno;  /* Save off */
1657	struct ocfs2_extent_rec *rec;
1658	struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1659	struct ocfs2_chain_list *cl = &di->id2.i_chain;
1660
1661	if (ocfs2_is_cluster_bitmap(ac->ac_inode)) {
1662		res->sr_blkno = 0;
1663		return;
1664	}
1665
1666	res->sr_blkno = res->sr_bg_blkno + res->sr_bit_offset;
1667	res->sr_bg_blkno = 0;  /* Clear it for contig block groups */
1668	if (!ocfs2_supports_discontig_bg(OCFS2_SB(ac->ac_inode->i_sb)) ||
1669	    !bg->bg_list.l_next_free_rec)
1670		return;
1671
1672	for (i = 0; i < le16_to_cpu(bg->bg_list.l_next_free_rec); i++) {
1673		rec = &bg->bg_list.l_recs[i];
1674		if (ocfs2_bg_discontig_fix_by_rec(res, rec, cl)) {
1675			res->sr_bg_blkno = bg_blkno;  /* Restore */
1676			break;
1677		}
1678	}
1679}
1680
1681static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
1682				  handle_t *handle,
1683				  u32 bits_wanted,
1684				  u32 min_bits,
1685				  struct ocfs2_suballoc_result *res,
1686				  u16 *bits_left)
1687{
1688	int ret;
1689	struct buffer_head *group_bh = NULL;
1690	struct ocfs2_group_desc *gd;
1691	struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1692	struct inode *alloc_inode = ac->ac_inode;
1693
1694	ret = ocfs2_read_group_descriptor(alloc_inode, di,
1695					  res->sr_bg_blkno, &group_bh);
1696	if (ret < 0) {
1697		mlog_errno(ret);
1698		return ret;
1699	}
1700
1701	gd = (struct ocfs2_group_desc *) group_bh->b_data;
1702	ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
1703				  ac->ac_max_block, res);
1704	if (ret < 0) {
1705		if (ret != -ENOSPC)
1706			mlog_errno(ret);
1707		goto out;
1708	}
1709
1710	if (!ret)
1711		ocfs2_bg_discontig_fix_result(ac, gd, res);
1712
1713	/*
1714	 * sr_bg_blkno might have been changed by
1715	 * ocfs2_bg_discontig_fix_result
1716	 */
1717	res->sr_bg_stable_blkno = group_bh->b_blocknr;
1718
1719	if (ac->ac_find_loc_only)
1720		goto out_loc_only;
1721
1722	ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
1723					       res->sr_bits,
1724					       le16_to_cpu(gd->bg_chain));
1725	if (ret < 0) {
1726		mlog_errno(ret);
1727		goto out;
1728	}
1729
1730	ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
1731					 res->sr_bit_offset, res->sr_bits);
1732	if (ret < 0) {
1733		ocfs2_rollback_alloc_dinode_counts(alloc_inode, ac->ac_bh,
1734					       res->sr_bits,
1735					       le16_to_cpu(gd->bg_chain));
1736		mlog_errno(ret);
1737	}
1738
1739out_loc_only:
1740	*bits_left = le16_to_cpu(gd->bg_free_bits_count);
1741
1742out:
1743	brelse(group_bh);
1744
1745	return ret;
1746}
1747
1748static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
1749			      handle_t *handle,
1750			      u32 bits_wanted,
1751			      u32 min_bits,
1752			      struct ocfs2_suballoc_result *res,
1753			      u16 *bits_left)
1754{
1755	int status;
1756	u16 chain;
1757	u64 next_group;
1758	struct inode *alloc_inode = ac->ac_inode;
1759	struct buffer_head *group_bh = NULL;
1760	struct buffer_head *prev_group_bh = NULL;
1761	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1762	struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1763	struct ocfs2_group_desc *bg;
1764
1765	chain = ac->ac_chain;
1766	trace_ocfs2_search_chain_begin(
1767		(unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
1768		bits_wanted, chain);
1769
1770	status = ocfs2_read_group_descriptor(alloc_inode, fe,
1771					     le64_to_cpu(cl->cl_recs[chain].c_blkno),
1772					     &group_bh);
1773	if (status < 0) {
1774		mlog_errno(status);
1775		goto bail;
1776	}
1777	bg = (struct ocfs2_group_desc *) group_bh->b_data;
1778
1779	status = -ENOSPC;
1780	/* for now, the chain search is a bit simplistic. We just use
1781	 * the 1st group with any empty bits. */
1782	while ((status = ac->ac_group_search(alloc_inode, group_bh,
1783					     bits_wanted, min_bits,
1784					     ac->ac_max_block,
1785					     res)) == -ENOSPC) {
1786		if (!bg->bg_next_group)
1787			break;
1788
1789		brelse(prev_group_bh);
1790		prev_group_bh = NULL;
1791
1792		next_group = le64_to_cpu(bg->bg_next_group);
1793		prev_group_bh = group_bh;
1794		group_bh = NULL;
1795		status = ocfs2_read_group_descriptor(alloc_inode, fe,
1796						     next_group, &group_bh);
1797		if (status < 0) {
1798			mlog_errno(status);
1799			goto bail;
1800		}
1801		bg = (struct ocfs2_group_desc *) group_bh->b_data;
1802	}
1803	if (status < 0) {
1804		if (status != -ENOSPC)
1805			mlog_errno(status);
1806		goto bail;
1807	}
1808
1809	trace_ocfs2_search_chain_succ(
1810		(unsigned long long)le64_to_cpu(bg->bg_blkno), res->sr_bits);
1811
1812	res->sr_bg_blkno = le64_to_cpu(bg->bg_blkno);
1813
1814	BUG_ON(res->sr_bits == 0);
1815	if (!status)
1816		ocfs2_bg_discontig_fix_result(ac, bg, res);
1817
1818	/*
1819	 * sr_bg_blkno might have been changed by
1820	 * ocfs2_bg_discontig_fix_result
1821	 */
1822	res->sr_bg_stable_blkno = group_bh->b_blocknr;
1823
1824	/*
1825	 * Keep track of previous block descriptor read. When
1826	 * we find a target, if we have read more than X
1827	 * number of descriptors, and the target is reasonably
1828	 * empty, relink him to top of his chain.
1829	 *
1830	 * We've read 0 extra blocks and only send one more to
1831	 * the transaction, yet the next guy to search has a
1832	 * much easier time.
1833	 *
1834	 * Do this *after* figuring out how many bits we're taking out
1835	 * of our target group.
1836	 */
1837	if (!ac->ac_disable_chain_relink &&
1838	    (prev_group_bh) &&
1839	    (ocfs2_block_group_reasonably_empty(bg, res->sr_bits))) {
1840		status = ocfs2_relink_block_group(handle, alloc_inode,
1841						  ac->ac_bh, group_bh,
1842						  prev_group_bh, chain);
1843		if (status < 0) {
1844			mlog_errno(status);
1845			goto bail;
1846		}
1847	}
1848
1849	if (ac->ac_find_loc_only)
1850		goto out_loc_only;
1851
1852	status = ocfs2_alloc_dinode_update_counts(alloc_inode, handle,
1853						  ac->ac_bh, res->sr_bits,
1854						  chain);
1855	if (status) {
1856		mlog_errno(status);
1857		goto bail;
1858	}
1859
1860	status = ocfs2_block_group_set_bits(handle,
1861					    alloc_inode,
1862					    bg,
1863					    group_bh,
1864					    res->sr_bit_offset,
1865					    res->sr_bits);
1866	if (status < 0) {
1867		ocfs2_rollback_alloc_dinode_counts(alloc_inode,
1868					ac->ac_bh, res->sr_bits, chain);
1869		mlog_errno(status);
1870		goto bail;
1871	}
1872
1873	trace_ocfs2_search_chain_end(
1874			(unsigned long long)le64_to_cpu(fe->i_blkno),
1875			res->sr_bits);
1876
1877out_loc_only:
1878	*bits_left = le16_to_cpu(bg->bg_free_bits_count);
1879bail:
1880	brelse(group_bh);
1881	brelse(prev_group_bh);
1882
1883	if (status)
1884		mlog_errno(status);
1885	return status;
1886}
1887
1888/* will give out up to bits_wanted contiguous bits. */
1889static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
1890				     handle_t *handle,
1891				     u32 bits_wanted,
1892				     u32 min_bits,
1893				     struct ocfs2_suballoc_result *res)
1894{
1895	int status;
1896	u16 victim, i;
1897	u16 bits_left = 0;
1898	u64 hint = ac->ac_last_group;
1899	struct ocfs2_chain_list *cl;
1900	struct ocfs2_dinode *fe;
1901
1902	BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1903	BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1904	BUG_ON(!ac->ac_bh);
1905
1906	fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1907
1908	/* The bh was validated by the inode read during
1909	 * ocfs2_reserve_suballoc_bits().  Any corruption is a code bug. */
1910	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
1911
1912	if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1913	    le32_to_cpu(fe->id1.bitmap1.i_total)) {
1914		status = ocfs2_error(ac->ac_inode->i_sb,
1915				     "Chain allocator dinode %llu has %u used bits but only %u total\n",
1916				     (unsigned long long)le64_to_cpu(fe->i_blkno),
1917				     le32_to_cpu(fe->id1.bitmap1.i_used),
1918				     le32_to_cpu(fe->id1.bitmap1.i_total));
 
 
1919		goto bail;
1920	}
1921
1922	res->sr_bg_blkno = hint;
1923	if (res->sr_bg_blkno) {
1924		/* Attempt to short-circuit the usual search mechanism
1925		 * by jumping straight to the most recently used
1926		 * allocation group. This helps us maintain some
1927		 * contiguousness across allocations. */
1928		status = ocfs2_search_one_group(ac, handle, bits_wanted,
1929						min_bits, res, &bits_left);
1930		if (!status)
1931			goto set_hint;
1932		if (status < 0 && status != -ENOSPC) {
1933			mlog_errno(status);
1934			goto bail;
1935		}
1936	}
1937
1938	cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1939
1940	victim = ocfs2_find_victim_chain(cl);
1941	ac->ac_chain = victim;
1942
1943	status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1944				    res, &bits_left);
1945	if (!status) {
1946		if (ocfs2_is_cluster_bitmap(ac->ac_inode))
1947			hint = res->sr_bg_blkno;
1948		else
1949			hint = ocfs2_group_from_res(res);
1950		goto set_hint;
1951	}
1952	if (status < 0 && status != -ENOSPC) {
1953		mlog_errno(status);
1954		goto bail;
1955	}
1956
1957	trace_ocfs2_claim_suballoc_bits(victim);
1958
1959	/* If we didn't pick a good victim, then just default to
1960	 * searching each chain in order. Don't allow chain relinking
1961	 * because we only calculate enough journal credits for one
1962	 * relink per alloc. */
1963	ac->ac_disable_chain_relink = 1;
1964	for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
1965		if (i == victim)
1966			continue;
1967		if (!cl->cl_recs[i].c_free)
1968			continue;
1969
1970		ac->ac_chain = i;
1971		status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1972					    res, &bits_left);
1973		if (!status) {
1974			hint = ocfs2_group_from_res(res);
1975			break;
1976		}
1977		if (status < 0 && status != -ENOSPC) {
1978			mlog_errno(status);
1979			goto bail;
1980		}
1981	}
1982
1983set_hint:
1984	if (status != -ENOSPC) {
1985		/* If the next search of this group is not likely to
1986		 * yield a suitable extent, then we reset the last
1987		 * group hint so as to not waste a disk read */
1988		if (bits_left < min_bits)
1989			ac->ac_last_group = 0;
1990		else
1991			ac->ac_last_group = hint;
1992	}
1993
1994bail:
1995	if (status)
1996		mlog_errno(status);
1997	return status;
1998}
1999
2000int ocfs2_claim_metadata(handle_t *handle,
2001			 struct ocfs2_alloc_context *ac,
2002			 u32 bits_wanted,
2003			 u64 *suballoc_loc,
2004			 u16 *suballoc_bit_start,
2005			 unsigned int *num_bits,
2006			 u64 *blkno_start)
2007{
2008	int status;
2009	struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
2010
2011	BUG_ON(!ac);
2012	BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
2013	BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
2014
2015	status = ocfs2_claim_suballoc_bits(ac,
2016					   handle,
2017					   bits_wanted,
2018					   1,
2019					   &res);
2020	if (status < 0) {
2021		mlog_errno(status);
2022		goto bail;
2023	}
2024	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2025
2026	*suballoc_loc = res.sr_bg_blkno;
2027	*suballoc_bit_start = res.sr_bit_offset;
2028	*blkno_start = res.sr_blkno;
2029	ac->ac_bits_given += res.sr_bits;
2030	*num_bits = res.sr_bits;
2031	status = 0;
2032bail:
2033	if (status)
2034		mlog_errno(status);
2035	return status;
2036}
2037
2038static void ocfs2_init_inode_ac_group(struct inode *dir,
2039				      struct buffer_head *parent_di_bh,
2040				      struct ocfs2_alloc_context *ac)
2041{
2042	struct ocfs2_dinode *di = (struct ocfs2_dinode *)parent_di_bh->b_data;
2043	/*
2044	 * Try to allocate inodes from some specific group.
2045	 *
2046	 * If the parent dir has recorded the last group used in allocation,
2047	 * cool, use it. Otherwise if we try to allocate new inode from the
2048	 * same slot the parent dir belongs to, use the same chunk.
2049	 *
2050	 * We are very careful here to avoid the mistake of setting
2051	 * ac_last_group to a group descriptor from a different (unlocked) slot.
2052	 */
2053	if (OCFS2_I(dir)->ip_last_used_group &&
2054	    OCFS2_I(dir)->ip_last_used_slot == ac->ac_alloc_slot)
2055		ac->ac_last_group = OCFS2_I(dir)->ip_last_used_group;
2056	else if (le16_to_cpu(di->i_suballoc_slot) == ac->ac_alloc_slot) {
2057		if (di->i_suballoc_loc)
2058			ac->ac_last_group = le64_to_cpu(di->i_suballoc_loc);
2059		else
2060			ac->ac_last_group = ocfs2_which_suballoc_group(
2061					le64_to_cpu(di->i_blkno),
2062					le16_to_cpu(di->i_suballoc_bit));
2063	}
2064}
2065
2066static inline void ocfs2_save_inode_ac_group(struct inode *dir,
2067					     struct ocfs2_alloc_context *ac)
2068{
2069	OCFS2_I(dir)->ip_last_used_group = ac->ac_last_group;
2070	OCFS2_I(dir)->ip_last_used_slot = ac->ac_alloc_slot;
2071}
2072
2073int ocfs2_find_new_inode_loc(struct inode *dir,
2074			     struct buffer_head *parent_fe_bh,
2075			     struct ocfs2_alloc_context *ac,
2076			     u64 *fe_blkno)
2077{
2078	int ret;
2079	handle_t *handle = NULL;
2080	struct ocfs2_suballoc_result *res;
2081
2082	BUG_ON(!ac);
2083	BUG_ON(ac->ac_bits_given != 0);
2084	BUG_ON(ac->ac_bits_wanted != 1);
2085	BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2086
2087	res = kzalloc(sizeof(*res), GFP_NOFS);
2088	if (res == NULL) {
2089		ret = -ENOMEM;
2090		mlog_errno(ret);
2091		goto out;
2092	}
2093
2094	ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2095
2096	/*
2097	 * The handle started here is for chain relink. Alternatively,
2098	 * we could just disable relink for these calls.
2099	 */
2100	handle = ocfs2_start_trans(OCFS2_SB(dir->i_sb), OCFS2_SUBALLOC_ALLOC);
2101	if (IS_ERR(handle)) {
2102		ret = PTR_ERR(handle);
2103		handle = NULL;
2104		mlog_errno(ret);
2105		goto out;
2106	}
2107
2108	/*
2109	 * This will instruct ocfs2_claim_suballoc_bits and
2110	 * ocfs2_search_one_group to search but save actual allocation
2111	 * for later.
2112	 */
2113	ac->ac_find_loc_only = 1;
2114
2115	ret = ocfs2_claim_suballoc_bits(ac, handle, 1, 1, res);
2116	if (ret < 0) {
2117		mlog_errno(ret);
2118		goto out;
2119	}
2120
2121	ac->ac_find_loc_priv = res;
2122	*fe_blkno = res->sr_blkno;
2123	ocfs2_update_inode_fsync_trans(handle, dir, 0);
2124out:
2125	if (handle)
2126		ocfs2_commit_trans(OCFS2_SB(dir->i_sb), handle);
2127
2128	if (ret)
2129		kfree(res);
2130
2131	return ret;
2132}
2133
2134int ocfs2_claim_new_inode_at_loc(handle_t *handle,
2135				 struct inode *dir,
2136				 struct ocfs2_alloc_context *ac,
2137				 u64 *suballoc_loc,
2138				 u16 *suballoc_bit,
2139				 u64 di_blkno)
2140{
2141	int ret;
2142	u16 chain;
2143	struct ocfs2_suballoc_result *res = ac->ac_find_loc_priv;
2144	struct buffer_head *bg_bh = NULL;
2145	struct ocfs2_group_desc *bg;
2146	struct ocfs2_dinode *di = (struct ocfs2_dinode *) ac->ac_bh->b_data;
2147
2148	/*
2149	 * Since di_blkno is being passed back in, we check for any
2150	 * inconsistencies which may have happened between
2151	 * calls. These are code bugs as di_blkno is not expected to
2152	 * change once returned from ocfs2_find_new_inode_loc()
2153	 */
2154	BUG_ON(res->sr_blkno != di_blkno);
2155
2156	ret = ocfs2_read_group_descriptor(ac->ac_inode, di,
2157					  res->sr_bg_stable_blkno, &bg_bh);
2158	if (ret) {
2159		mlog_errno(ret);
2160		goto out;
2161	}
2162
2163	bg = (struct ocfs2_group_desc *) bg_bh->b_data;
2164	chain = le16_to_cpu(bg->bg_chain);
2165
2166	ret = ocfs2_alloc_dinode_update_counts(ac->ac_inode, handle,
2167					       ac->ac_bh, res->sr_bits,
2168					       chain);
2169	if (ret) {
2170		mlog_errno(ret);
2171		goto out;
2172	}
2173
2174	ret = ocfs2_block_group_set_bits(handle,
2175					 ac->ac_inode,
2176					 bg,
2177					 bg_bh,
2178					 res->sr_bit_offset,
2179					 res->sr_bits);
2180	if (ret < 0) {
2181		ocfs2_rollback_alloc_dinode_counts(ac->ac_inode,
2182					       ac->ac_bh, res->sr_bits, chain);
2183		mlog_errno(ret);
2184		goto out;
2185	}
2186
2187	trace_ocfs2_claim_new_inode_at_loc((unsigned long long)di_blkno,
2188					   res->sr_bits);
2189
2190	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2191
2192	BUG_ON(res->sr_bits != 1);
2193
2194	*suballoc_loc = res->sr_bg_blkno;
2195	*suballoc_bit = res->sr_bit_offset;
2196	ac->ac_bits_given++;
2197	ocfs2_save_inode_ac_group(dir, ac);
2198
2199out:
2200	brelse(bg_bh);
2201
2202	return ret;
2203}
2204
2205int ocfs2_claim_new_inode(handle_t *handle,
2206			  struct inode *dir,
2207			  struct buffer_head *parent_fe_bh,
2208			  struct ocfs2_alloc_context *ac,
2209			  u64 *suballoc_loc,
2210			  u16 *suballoc_bit,
2211			  u64 *fe_blkno)
2212{
2213	int status;
2214	struct ocfs2_suballoc_result res;
2215
2216	BUG_ON(!ac);
2217	BUG_ON(ac->ac_bits_given != 0);
2218	BUG_ON(ac->ac_bits_wanted != 1);
2219	BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2220
2221	ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2222
2223	status = ocfs2_claim_suballoc_bits(ac,
2224					   handle,
2225					   1,
2226					   1,
2227					   &res);
2228	if (status < 0) {
2229		mlog_errno(status);
2230		goto bail;
2231	}
2232	atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2233
2234	BUG_ON(res.sr_bits != 1);
2235
2236	*suballoc_loc = res.sr_bg_blkno;
2237	*suballoc_bit = res.sr_bit_offset;
2238	*fe_blkno = res.sr_blkno;
2239	ac->ac_bits_given++;
2240	ocfs2_save_inode_ac_group(dir, ac);
2241	status = 0;
2242bail:
2243	if (status)
2244		mlog_errno(status);
2245	return status;
2246}
2247
2248/* translate a group desc. blkno and it's bitmap offset into
2249 * disk cluster offset. */
2250static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
2251						   u64 bg_blkno,
2252						   u16 bg_bit_off)
2253{
2254	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2255	u32 cluster = 0;
2256
2257	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2258
2259	if (bg_blkno != osb->first_cluster_group_blkno)
2260		cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
2261	cluster += (u32) bg_bit_off;
2262	return cluster;
2263}
2264
2265/* given a cluster offset, calculate which block group it belongs to
2266 * and return that block offset. */
2267u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster)
2268{
2269	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2270	u32 group_no;
2271
2272	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2273
2274	group_no = cluster / osb->bitmap_cpg;
2275	if (!group_no)
2276		return osb->first_cluster_group_blkno;
2277	return ocfs2_clusters_to_blocks(inode->i_sb,
2278					group_no * osb->bitmap_cpg);
2279}
2280
2281/* given the block number of a cluster start, calculate which cluster
2282 * group and descriptor bitmap offset that corresponds to. */
2283static inline void ocfs2_block_to_cluster_group(struct inode *inode,
2284						u64 data_blkno,
2285						u64 *bg_blkno,
2286						u16 *bg_bit_off)
2287{
2288	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2289	u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
2290
2291	BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2292
2293	*bg_blkno = ocfs2_which_cluster_group(inode,
2294					      data_cluster);
2295
2296	if (*bg_blkno == osb->first_cluster_group_blkno)
2297		*bg_bit_off = (u16) data_cluster;
2298	else
2299		*bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
2300							     data_blkno - *bg_blkno);
2301}
2302
2303/*
2304 * min_bits - minimum contiguous chunk from this total allocation we
2305 * can handle. set to what we asked for originally for a full
2306 * contig. allocation, set to '1' to indicate we can deal with extents
2307 * of any size.
2308 */
2309int __ocfs2_claim_clusters(handle_t *handle,
2310			   struct ocfs2_alloc_context *ac,
2311			   u32 min_clusters,
2312			   u32 max_clusters,
2313			   u32 *cluster_start,
2314			   u32 *num_clusters)
2315{
2316	int status;
2317	unsigned int bits_wanted = max_clusters;
2318	struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
2319	struct ocfs2_super *osb = OCFS2_SB(ac->ac_inode->i_sb);
2320
2321	BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
2322
2323	BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
2324	       && ac->ac_which != OCFS2_AC_USE_MAIN);
2325
2326	if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
2327		WARN_ON(min_clusters > 1);
2328
2329		status = ocfs2_claim_local_alloc_bits(osb,
2330						      handle,
2331						      ac,
2332						      bits_wanted,
2333						      cluster_start,
2334						      num_clusters);
2335		if (!status)
2336			atomic_inc(&osb->alloc_stats.local_data);
2337	} else {
2338		if (min_clusters > (osb->bitmap_cpg - 1)) {
2339			/* The only paths asking for contiguousness
2340			 * should know about this already. */
2341			mlog(ML_ERROR, "minimum allocation requested %u exceeds "
2342			     "group bitmap size %u!\n", min_clusters,
2343			     osb->bitmap_cpg);
2344			status = -ENOSPC;
2345			goto bail;
2346		}
2347		/* clamp the current request down to a realistic size. */
2348		if (bits_wanted > (osb->bitmap_cpg - 1))
2349			bits_wanted = osb->bitmap_cpg - 1;
2350
2351		status = ocfs2_claim_suballoc_bits(ac,
2352						   handle,
2353						   bits_wanted,
2354						   min_clusters,
2355						   &res);
2356		if (!status) {
2357			BUG_ON(res.sr_blkno); /* cluster alloc can't set */
2358			*cluster_start =
2359				ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
2360								 res.sr_bg_blkno,
2361								 res.sr_bit_offset);
2362			atomic_inc(&osb->alloc_stats.bitmap_data);
2363			*num_clusters = res.sr_bits;
2364		}
2365	}
2366	if (status < 0) {
2367		if (status != -ENOSPC)
2368			mlog_errno(status);
2369		goto bail;
2370	}
2371
2372	ac->ac_bits_given += *num_clusters;
2373
2374bail:
2375	if (status)
2376		mlog_errno(status);
2377	return status;
2378}
2379
2380int ocfs2_claim_clusters(handle_t *handle,
2381			 struct ocfs2_alloc_context *ac,
2382			 u32 min_clusters,
2383			 u32 *cluster_start,
2384			 u32 *num_clusters)
2385{
2386	unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
2387
2388	return __ocfs2_claim_clusters(handle, ac, min_clusters,
2389				      bits_wanted, cluster_start, num_clusters);
2390}
2391
2392static int ocfs2_block_group_clear_bits(handle_t *handle,
2393					struct inode *alloc_inode,
2394					struct ocfs2_group_desc *bg,
2395					struct buffer_head *group_bh,
2396					unsigned int bit_off,
2397					unsigned int num_bits,
2398					void (*undo_fn)(unsigned int bit,
2399							unsigned long *bmap))
2400{
2401	int status;
2402	unsigned int tmp;
2403	struct ocfs2_group_desc *undo_bg = NULL;
2404
2405	/* The caller got this descriptor from
2406	 * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
2407	BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
2408
2409	trace_ocfs2_block_group_clear_bits(bit_off, num_bits);
2410
2411	BUG_ON(undo_fn && !ocfs2_is_cluster_bitmap(alloc_inode));
2412	status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
2413					 group_bh,
2414					 undo_fn ?
2415					 OCFS2_JOURNAL_ACCESS_UNDO :
2416					 OCFS2_JOURNAL_ACCESS_WRITE);
2417	if (status < 0) {
2418		mlog_errno(status);
2419		goto bail;
2420	}
2421
2422	if (undo_fn) {
2423		jbd_lock_bh_state(group_bh);
2424		undo_bg = (struct ocfs2_group_desc *)
2425					bh2jh(group_bh)->b_committed_data;
2426		BUG_ON(!undo_bg);
2427	}
2428
2429	tmp = num_bits;
2430	while(tmp--) {
2431		ocfs2_clear_bit((bit_off + tmp),
2432				(unsigned long *) bg->bg_bitmap);
2433		if (undo_fn)
2434			undo_fn(bit_off + tmp,
2435				(unsigned long *) undo_bg->bg_bitmap);
2436	}
2437	le16_add_cpu(&bg->bg_free_bits_count, num_bits);
2438	if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
2439		if (undo_fn)
2440			jbd_unlock_bh_state(group_bh);
2441		return ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit count %u but claims %u are freed. num_bits %d\n",
2442				   (unsigned long long)le64_to_cpu(bg->bg_blkno),
2443				   le16_to_cpu(bg->bg_bits),
2444				   le16_to_cpu(bg->bg_free_bits_count),
2445				   num_bits);
2446	}
2447
2448	if (undo_fn)
2449		jbd_unlock_bh_state(group_bh);
2450
2451	ocfs2_journal_dirty(handle, group_bh);
2452bail:
2453	return status;
2454}
2455
2456/*
2457 * expects the suballoc inode to already be locked.
2458 */
2459static int _ocfs2_free_suballoc_bits(handle_t *handle,
2460				     struct inode *alloc_inode,
2461				     struct buffer_head *alloc_bh,
2462				     unsigned int start_bit,
2463				     u64 bg_blkno,
2464				     unsigned int count,
2465				     void (*undo_fn)(unsigned int bit,
2466						     unsigned long *bitmap))
2467{
2468	int status = 0;
2469	u32 tmp_used;
2470	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
2471	struct ocfs2_chain_list *cl = &fe->id2.i_chain;
2472	struct buffer_head *group_bh = NULL;
2473	struct ocfs2_group_desc *group;
2474
2475	/* The alloc_bh comes from ocfs2_free_dinode() or
2476	 * ocfs2_free_clusters().  The callers have all locked the
2477	 * allocator and gotten alloc_bh from the lock call.  This
2478	 * validates the dinode buffer.  Any corruption that has happened
2479	 * is a code bug. */
2480	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
2481	BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
2482
2483	trace_ocfs2_free_suballoc_bits(
2484		(unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
2485		(unsigned long long)bg_blkno,
2486		start_bit, count);
2487
2488	status = ocfs2_read_group_descriptor(alloc_inode, fe, bg_blkno,
2489					     &group_bh);
2490	if (status < 0) {
2491		mlog_errno(status);
2492		goto bail;
2493	}
2494	group = (struct ocfs2_group_desc *) group_bh->b_data;
2495
2496	BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
2497
2498	status = ocfs2_block_group_clear_bits(handle, alloc_inode,
2499					      group, group_bh,
2500					      start_bit, count, undo_fn);
2501	if (status < 0) {
2502		mlog_errno(status);
2503		goto bail;
2504	}
2505
2506	status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
2507					 alloc_bh, OCFS2_JOURNAL_ACCESS_WRITE);
2508	if (status < 0) {
2509		mlog_errno(status);
2510		ocfs2_block_group_set_bits(handle, alloc_inode, group, group_bh,
2511				start_bit, count);
2512		goto bail;
2513	}
2514
2515	le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
2516		     count);
2517	tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
2518	fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
2519	ocfs2_journal_dirty(handle, alloc_bh);
2520
2521bail:
2522	brelse(group_bh);
2523
2524	if (status)
2525		mlog_errno(status);
2526	return status;
2527}
2528
2529int ocfs2_free_suballoc_bits(handle_t *handle,
2530			     struct inode *alloc_inode,
2531			     struct buffer_head *alloc_bh,
2532			     unsigned int start_bit,
2533			     u64 bg_blkno,
2534			     unsigned int count)
2535{
2536	return _ocfs2_free_suballoc_bits(handle, alloc_inode, alloc_bh,
2537					 start_bit, bg_blkno, count, NULL);
2538}
2539
2540int ocfs2_free_dinode(handle_t *handle,
2541		      struct inode *inode_alloc_inode,
2542		      struct buffer_head *inode_alloc_bh,
2543		      struct ocfs2_dinode *di)
2544{
2545	u64 blk = le64_to_cpu(di->i_blkno);
2546	u16 bit = le16_to_cpu(di->i_suballoc_bit);
2547	u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
2548
2549	if (di->i_suballoc_loc)
2550		bg_blkno = le64_to_cpu(di->i_suballoc_loc);
2551	return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
2552					inode_alloc_bh, bit, bg_blkno, 1);
2553}
2554
2555static int _ocfs2_free_clusters(handle_t *handle,
2556				struct inode *bitmap_inode,
2557				struct buffer_head *bitmap_bh,
2558				u64 start_blk,
2559				unsigned int num_clusters,
2560				void (*undo_fn)(unsigned int bit,
2561						unsigned long *bitmap))
2562{
2563	int status;
2564	u16 bg_start_bit;
2565	u64 bg_blkno;
 
2566
2567	/* You can't ever have a contiguous set of clusters
2568	 * bigger than a block group bitmap so we never have to worry
2569	 * about looping on them.
2570	 * This is expensive. We can safely remove once this stuff has
2571	 * gotten tested really well. */
2572	BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb,
2573				ocfs2_blocks_to_clusters(bitmap_inode->i_sb,
2574							 start_blk)));
2575
 
2576
2577	ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
2578				     &bg_start_bit);
2579
2580	trace_ocfs2_free_clusters((unsigned long long)bg_blkno,
2581			(unsigned long long)start_blk,
2582			bg_start_bit, num_clusters);
2583
2584	status = _ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
2585					   bg_start_bit, bg_blkno,
2586					   num_clusters, undo_fn);
2587	if (status < 0) {
2588		mlog_errno(status);
2589		goto out;
2590	}
2591
2592	ocfs2_local_alloc_seen_free_bits(OCFS2_SB(bitmap_inode->i_sb),
2593					 num_clusters);
2594
2595out:
2596	if (status)
2597		mlog_errno(status);
2598	return status;
2599}
2600
2601int ocfs2_free_clusters(handle_t *handle,
2602			struct inode *bitmap_inode,
2603			struct buffer_head *bitmap_bh,
2604			u64 start_blk,
2605			unsigned int num_clusters)
2606{
2607	return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2608				    start_blk, num_clusters,
2609				    _ocfs2_set_bit);
2610}
2611
2612/*
2613 * Give never-used clusters back to the global bitmap.  We don't need
2614 * to protect these bits in the undo buffer.
2615 */
2616int ocfs2_release_clusters(handle_t *handle,
2617			   struct inode *bitmap_inode,
2618			   struct buffer_head *bitmap_bh,
2619			   u64 start_blk,
2620			   unsigned int num_clusters)
2621{
2622	return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2623				    start_blk, num_clusters,
2624				    _ocfs2_clear_bit);
2625}
2626
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2627/*
2628 * For a given allocation, determine which allocators will need to be
2629 * accessed, and lock them, reserving the appropriate number of bits.
2630 *
2631 * Sparse file systems call this from ocfs2_write_begin_nolock()
2632 * and ocfs2_allocate_unwritten_extents().
2633 *
2634 * File systems which don't support holes call this from
2635 * ocfs2_extend_allocation().
2636 */
2637int ocfs2_lock_allocators(struct inode *inode,
2638			  struct ocfs2_extent_tree *et,
2639			  u32 clusters_to_add, u32 extents_to_split,
2640			  struct ocfs2_alloc_context **data_ac,
2641			  struct ocfs2_alloc_context **meta_ac)
2642{
2643	int ret = 0, num_free_extents;
2644	unsigned int max_recs_needed = clusters_to_add + 2 * extents_to_split;
2645	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2646
2647	*meta_ac = NULL;
2648	if (data_ac)
2649		*data_ac = NULL;
2650
2651	BUG_ON(clusters_to_add != 0 && data_ac == NULL);
2652
2653	num_free_extents = ocfs2_num_free_extents(et);
2654	if (num_free_extents < 0) {
2655		ret = num_free_extents;
2656		mlog_errno(ret);
2657		goto out;
2658	}
2659
2660	/*
2661	 * Sparse allocation file systems need to be more conservative
2662	 * with reserving room for expansion - the actual allocation
2663	 * happens while we've got a journal handle open so re-taking
2664	 * a cluster lock (because we ran out of room for another
2665	 * extent) will violate ordering rules.
2666	 *
2667	 * Most of the time we'll only be seeing this 1 cluster at a time
2668	 * anyway.
2669	 *
2670	 * Always lock for any unwritten extents - we might want to
2671	 * add blocks during a split.
2672	 */
2673	if (!num_free_extents ||
2674	    (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed)) {
2675		ret = ocfs2_reserve_new_metadata(osb, et->et_root_el, meta_ac);
2676		if (ret < 0) {
2677			if (ret != -ENOSPC)
2678				mlog_errno(ret);
2679			goto out;
2680		}
2681	}
2682
2683	if (clusters_to_add == 0)
2684		goto out;
2685
2686	ret = ocfs2_reserve_clusters(osb, clusters_to_add, data_ac);
2687	if (ret < 0) {
2688		if (ret != -ENOSPC)
2689			mlog_errno(ret);
2690		goto out;
2691	}
2692
2693out:
2694	if (ret) {
2695		if (*meta_ac) {
2696			ocfs2_free_alloc_context(*meta_ac);
2697			*meta_ac = NULL;
2698		}
2699
2700		/*
2701		 * We cannot have an error and a non null *data_ac.
2702		 */
2703	}
2704
2705	return ret;
2706}
2707
2708/*
2709 * Read the inode specified by blkno to get suballoc_slot and
2710 * suballoc_bit.
2711 */
2712static int ocfs2_get_suballoc_slot_bit(struct ocfs2_super *osb, u64 blkno,
2713				       u16 *suballoc_slot, u64 *group_blkno,
2714				       u16 *suballoc_bit)
2715{
2716	int status;
2717	struct buffer_head *inode_bh = NULL;
2718	struct ocfs2_dinode *inode_fe;
2719
2720	trace_ocfs2_get_suballoc_slot_bit((unsigned long long)blkno);
2721
2722	/* dirty read disk */
2723	status = ocfs2_read_blocks_sync(osb, blkno, 1, &inode_bh);
2724	if (status < 0) {
2725		mlog(ML_ERROR, "read block %llu failed %d\n",
2726		     (unsigned long long)blkno, status);
2727		goto bail;
2728	}
2729
2730	inode_fe = (struct ocfs2_dinode *) inode_bh->b_data;
2731	if (!OCFS2_IS_VALID_DINODE(inode_fe)) {
2732		mlog(ML_ERROR, "invalid inode %llu requested\n",
2733		     (unsigned long long)blkno);
2734		status = -EINVAL;
2735		goto bail;
2736	}
2737
2738	if (le16_to_cpu(inode_fe->i_suballoc_slot) != (u16)OCFS2_INVALID_SLOT &&
2739	    (u32)le16_to_cpu(inode_fe->i_suballoc_slot) > osb->max_slots - 1) {
2740		mlog(ML_ERROR, "inode %llu has invalid suballoc slot %u\n",
2741		     (unsigned long long)blkno,
2742		     (u32)le16_to_cpu(inode_fe->i_suballoc_slot));
2743		status = -EINVAL;
2744		goto bail;
2745	}
2746
2747	if (suballoc_slot)
2748		*suballoc_slot = le16_to_cpu(inode_fe->i_suballoc_slot);
2749	if (suballoc_bit)
2750		*suballoc_bit = le16_to_cpu(inode_fe->i_suballoc_bit);
2751	if (group_blkno)
2752		*group_blkno = le64_to_cpu(inode_fe->i_suballoc_loc);
2753
2754bail:
2755	brelse(inode_bh);
2756
2757	if (status)
2758		mlog_errno(status);
2759	return status;
2760}
2761
2762/*
2763 * test whether bit is SET in allocator bitmap or not.  on success, 0
2764 * is returned and *res is 1 for SET; 0 otherwise.  when fails, errno
2765 * is returned and *res is meaningless.  Call this after you have
2766 * cluster locked against suballoc, or you may get a result based on
2767 * non-up2date contents
2768 */
2769static int ocfs2_test_suballoc_bit(struct ocfs2_super *osb,
2770				   struct inode *suballoc,
2771				   struct buffer_head *alloc_bh,
2772				   u64 group_blkno, u64 blkno,
2773				   u16 bit, int *res)
2774{
2775	struct ocfs2_dinode *alloc_di;
2776	struct ocfs2_group_desc *group;
2777	struct buffer_head *group_bh = NULL;
2778	u64 bg_blkno;
2779	int status;
2780
2781	trace_ocfs2_test_suballoc_bit((unsigned long long)blkno,
2782				      (unsigned int)bit);
2783
2784	alloc_di = (struct ocfs2_dinode *)alloc_bh->b_data;
2785	if ((bit + 1) > ocfs2_bits_per_group(&alloc_di->id2.i_chain)) {
2786		mlog(ML_ERROR, "suballoc bit %u out of range of %u\n",
2787		     (unsigned int)bit,
2788		     ocfs2_bits_per_group(&alloc_di->id2.i_chain));
2789		status = -EINVAL;
2790		goto bail;
2791	}
2792
2793	bg_blkno = group_blkno ? group_blkno :
2794		   ocfs2_which_suballoc_group(blkno, bit);
2795	status = ocfs2_read_group_descriptor(suballoc, alloc_di, bg_blkno,
2796					     &group_bh);
2797	if (status < 0) {
2798		mlog(ML_ERROR, "read group %llu failed %d\n",
2799		     (unsigned long long)bg_blkno, status);
2800		goto bail;
2801	}
2802
2803	group = (struct ocfs2_group_desc *) group_bh->b_data;
2804	*res = ocfs2_test_bit(bit, (unsigned long *)group->bg_bitmap);
2805
2806bail:
2807	brelse(group_bh);
2808
2809	if (status)
2810		mlog_errno(status);
2811	return status;
2812}
2813
2814/*
2815 * Test if the bit representing this inode (blkno) is set in the
2816 * suballocator.
2817 *
2818 * On success, 0 is returned and *res is 1 for SET; 0 otherwise.
2819 *
2820 * In the event of failure, a negative value is returned and *res is
2821 * meaningless.
2822 *
2823 * Callers must make sure to hold nfs_sync_lock to prevent
2824 * ocfs2_delete_inode() on another node from accessing the same
2825 * suballocator concurrently.
2826 */
2827int ocfs2_test_inode_bit(struct ocfs2_super *osb, u64 blkno, int *res)
2828{
2829	int status;
2830	u64 group_blkno = 0;
2831	u16 suballoc_bit = 0, suballoc_slot = 0;
2832	struct inode *inode_alloc_inode;
2833	struct buffer_head *alloc_bh = NULL;
2834
2835	trace_ocfs2_test_inode_bit((unsigned long long)blkno);
2836
2837	status = ocfs2_get_suballoc_slot_bit(osb, blkno, &suballoc_slot,
2838					     &group_blkno, &suballoc_bit);
2839	if (status < 0) {
2840		mlog(ML_ERROR, "get alloc slot and bit failed %d\n", status);
2841		goto bail;
2842	}
2843
2844	inode_alloc_inode =
2845		ocfs2_get_system_file_inode(osb, INODE_ALLOC_SYSTEM_INODE,
2846					    suballoc_slot);
2847	if (!inode_alloc_inode) {
2848		/* the error code could be inaccurate, but we are not able to
2849		 * get the correct one. */
2850		status = -EINVAL;
2851		mlog(ML_ERROR, "unable to get alloc inode in slot %u\n",
2852		     (u32)suballoc_slot);
2853		goto bail;
2854	}
2855
2856	inode_lock(inode_alloc_inode);
2857	status = ocfs2_inode_lock(inode_alloc_inode, &alloc_bh, 0);
2858	if (status < 0) {
2859		inode_unlock(inode_alloc_inode);
2860		iput(inode_alloc_inode);
2861		mlog(ML_ERROR, "lock on alloc inode on slot %u failed %d\n",
2862		     (u32)suballoc_slot, status);
2863		goto bail;
2864	}
2865
2866	status = ocfs2_test_suballoc_bit(osb, inode_alloc_inode, alloc_bh,
2867					 group_blkno, blkno, suballoc_bit, res);
2868	if (status < 0)
2869		mlog(ML_ERROR, "test suballoc bit failed %d\n", status);
2870
2871	ocfs2_inode_unlock(inode_alloc_inode, 0);
2872	inode_unlock(inode_alloc_inode);
2873
2874	iput(inode_alloc_inode);
2875	brelse(alloc_bh);
2876bail:
2877	if (status)
2878		mlog_errno(status);
2879	return status;
2880}