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