fs/ocfs2/suballoc.c

   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
  56 struct 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
  71 static 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
  82 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg);
  83 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe);
  84 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl);
  85 static 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);
  92 static 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
  99 static 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);
 104 static 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);
 109 static 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);
 114 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
 115                                          int nr);
 116 static 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);
 122 static 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);
 128 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
 129                                                      u32 wanted);
 130 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
 131                                                    u64 bg_blkno,
 132                                                    u16 bg_bit_off);
 133 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
 134                                                 u64 data_blkno,
 135                                                 u64 *bg_blkno,
 136                                                 u16 *bg_bit_off);
 137 static 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
 142 void 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
 164 void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
 165 {
 166         ocfs2_free_ac_resource(ac);
 167         kfree(ac);
 168 }
 169
 170 static 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
 183 static 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
 233 static 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  */
 278 int 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
 305 static 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
 332 int 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
 353 out:
 354         return rc;
 355 }
 356
 357 static 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
 379 static 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
 436 bail:
 437         if (status)
 438                 mlog_errno(status);
 439         return status;
 440 }
 441
 442 static 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
 456 static struct buffer_head *
 457 ocfs2_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
 497 bail:
 498         return status ? ERR_PTR(status) : bg_bh;
 499 }
 500
 501 static 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
 521 static 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
 579 bail:
 580         return status;
 581 }
 582
 583 static 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
 613 static struct buffer_head *
 614 ocfs2_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
 682 bail:
 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  */
 691 static 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
 787 bail:
 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
 801 static 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;
 885 bail:
 886         brelse(bh);
 887
 888         if (status)
 889                 mlog_errno(status);
 890         return status;
 891 }
 892
 893 static 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
 901 static 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
 909 void 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
 915 static 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
 925 static 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
 939 static int ocfs2_get_inode_steal_slot(struct ocfs2_super *osb)
 940 {
 941         return __ocfs2_get_steal_slot(osb, INODE_ALLOC_SYSTEM_INODE);
 942 }
 943
 944 static int ocfs2_get_meta_steal_slot(struct ocfs2_super *osb)
 945 {
 946         return __ocfs2_get_steal_slot(osb, EXTENT_ALLOC_SYSTEM_INODE);
 947 }
 948
 949 static 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
 982 static 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
 988 static 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
 994 int 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
1035 extent_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;
1045 bail:
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
1056 int 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
1065 int 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
1136 inode_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;
1146 bail:
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.. */
1159 int 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
1176 bail:
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. */
1183 static 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;
1222 bail:
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
1233 int 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  */
1263 static 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
1286 static 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
1346 static 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
1390 bail:
1391         if (status)
1392                 mlog_errno(status);
1393         return status;
1394 }
1395
1396 /* find the one with the most empty bits */
1397 static 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
1415 static int ocfs2_relink_block_group(handle_t *handle,
1416                                     struct inode *alloc_inode,
1417                                     struct buffer_head *fe_bh,
1418                                     struct buffer_head *bg_bh,
1419                                     struct buffer_head *prev_bg_bh,
1420                                     u16 chain)
1421 {
1422         int status;
1423         /* there is a really tiny chance the journal calls could fail,
1424          * but we wouldn't want inconsistent blocks in *any* case. */
1425         u64 fe_ptr, bg_ptr, prev_bg_ptr;
1426         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
1427         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1428         struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
1429
1430         /* The caller got these descriptors from
1431          * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1432         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1433         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(prev_bg));
1434
1435         trace_ocfs2_relink_block_group(
1436                 (unsigned long long)le64_to_cpu(fe->i_blkno), chain,
1437                 (unsigned long long)le64_to_cpu(bg->bg_blkno),
1438                 (unsigned long long)le64_to_cpu(prev_bg->bg_blkno));
1439
1440         fe_ptr = le64_to_cpu(fe->id2.i_chain.cl_recs[chain].c_blkno);
1441         bg_ptr = le64_to_cpu(bg->bg_next_group);
1442         prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
1443
1444         status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1445                                          prev_bg_bh,
1446                                          OCFS2_JOURNAL_ACCESS_WRITE);
1447         if (status < 0) {
1448                 mlog_errno(status);
1449                 goto out_rollback;
1450         }
1451
1452         prev_bg->bg_next_group = bg->bg_next_group;
1453         ocfs2_journal_dirty(handle, prev_bg_bh);
1454
1455         status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1456                                          bg_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1457         if (status < 0) {
1458                 mlog_errno(status);
1459                 goto out_rollback;
1460         }
1461
1462         bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
1463         ocfs2_journal_dirty(handle, bg_bh);
1464
1465         status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
1466                                          fe_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1467         if (status < 0) {
1468                 mlog_errno(status);
1469                 goto out_rollback;
1470         }
1471
1472         fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
1473         ocfs2_journal_dirty(handle, fe_bh);
1474
1475 out_rollback:
1476         if (status < 0) {
1477                 fe->id2.i_chain.cl_recs[chain].c_blkno = cpu_to_le64(fe_ptr);
1478                 bg->bg_next_group = cpu_to_le64(bg_ptr);
1479                 prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
1480         }
1481
1482         if (status)
1483                 mlog_errno(status);
1484         return status;
1485 }
1486
1487 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
1488                                                      u32 wanted)
1489 {
1490         return le16_to_cpu(bg->bg_free_bits_count) > wanted;
1491 }
1492
1493 /* return 0 on success, -ENOSPC to keep searching and any other < 0
1494  * value on error. */
1495 static int ocfs2_cluster_group_search(struct inode *inode,
1496                                       struct buffer_head *group_bh,
1497                                       u32 bits_wanted, u32 min_bits,
1498                                       u64 max_block,
1499                                       struct ocfs2_suballoc_result *res)
1500 {
1501         int search = -ENOSPC;
1502         int ret;
1503         u64 blkoff;
1504         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
1505         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1506         unsigned int max_bits, gd_cluster_off;
1507
1508         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1509
1510         if (gd->bg_free_bits_count) {
1511                 max_bits = le16_to_cpu(gd->bg_bits);
1512
1513                 /* Tail groups in cluster bitmaps which aren't cpg
1514                  * aligned are prone to partial extension by a failed
1515                  * fs resize. If the file system resize never got to
1516                  * update the dinode cluster count, then we don't want
1517                  * to trust any clusters past it, regardless of what
1518                  * the group descriptor says. */
1519                 gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
1520                                                           le64_to_cpu(gd->bg_blkno));
1521                 if ((gd_cluster_off + max_bits) >
1522                     OCFS2_I(inode)->ip_clusters) {
1523                         max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
1524                         trace_ocfs2_cluster_group_search_wrong_max_bits(
1525                                 (unsigned long long)le64_to_cpu(gd->bg_blkno),
1526                                 le16_to_cpu(gd->bg_bits),
1527                                 OCFS2_I(inode)->ip_clusters, max_bits);
1528                 }
1529
1530                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1531                                                         group_bh, bits_wanted,
1532                                                         max_bits, res);
1533                 if (ret)
1534                         return ret;
1535
1536                 if (max_block) {
1537                         blkoff = ocfs2_clusters_to_blocks(inode->i_sb,
1538                                                           gd_cluster_off +
1539                                                           res->sr_bit_offset +
1540                                                           res->sr_bits);
1541                         trace_ocfs2_cluster_group_search_max_block(
1542                                 (unsigned long long)blkoff,
1543                                 (unsigned long long)max_block);
1544                         if (blkoff > max_block)
1545                                 return -ENOSPC;
1546                 }
1547
1548                 /* ocfs2_block_group_find_clear_bits() might
1549                  * return success, but we still want to return
1550                  * -ENOSPC unless it found the minimum number
1551                  * of bits. */
1552                 if (min_bits <= res->sr_bits)
1553                         search = 0; /* success */
1554                 else if (res->sr_bits) {
1555                         /*
1556                          * Don't show bits which we'll be returning
1557                          * for allocation to the local alloc bitmap.
1558                          */
1559                         ocfs2_local_alloc_seen_free_bits(osb, res->sr_bits);
1560                 }
1561         }
1562
1563         return search;
1564 }
1565
1566 static int ocfs2_block_group_search(struct inode *inode,
1567                                     struct buffer_head *group_bh,
1568                                     u32 bits_wanted, u32 min_bits,
1569                                     u64 max_block,
1570                                     struct ocfs2_suballoc_result *res)
1571 {
1572         int ret = -ENOSPC;
1573         u64 blkoff;
1574         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
1575
1576         BUG_ON(min_bits != 1);
1577         BUG_ON(ocfs2_is_cluster_bitmap(inode));
1578
1579         if (bg->bg_free_bits_count) {
1580                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1581                                                         group_bh, bits_wanted,
1582                                                         le16_to_cpu(bg->bg_bits),
1583                                                         res);
1584                 if (!ret && max_block) {
1585                         blkoff = le64_to_cpu(bg->bg_blkno) +
1586                                 res->sr_bit_offset + res->sr_bits;
1587                         trace_ocfs2_block_group_search_max_block(
1588                                 (unsigned long long)blkoff,
1589                                 (unsigned long long)max_block);
1590                         if (blkoff > max_block)
1591                                 ret = -ENOSPC;
1592                 }
1593         }
1594
1595         return ret;
1596 }
1597
1598 static int ocfs2_alloc_dinode_update_counts(struct inode *inode,
1599                                        handle_t *handle,
1600                                        struct buffer_head *di_bh,
1601                                        u32 num_bits,
1602                                        u16 chain)
1603 {
1604         int ret;
1605         u32 tmp_used;
1606         struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1607         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &di->id2.i_chain;
1608
1609         ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
1610                                       OCFS2_JOURNAL_ACCESS_WRITE);
1611         if (ret < 0) {
1612                 mlog_errno(ret);
1613                 goto out;
1614         }
1615
1616         tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1617         di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
1618         le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
1619         ocfs2_journal_dirty(handle, di_bh);
1620
1621 out:
1622         return ret;
1623 }
1624
1625 static int ocfs2_bg_discontig_fix_by_rec(struct ocfs2_suballoc_result *res,
1626                                          struct ocfs2_extent_rec *rec,
1627                                          struct ocfs2_chain_list *cl)
1628 {
1629         unsigned int bpc = le16_to_cpu(cl->cl_bpc);
1630         unsigned int bitoff = le32_to_cpu(rec->e_cpos) * bpc;
1631         unsigned int bitcount = le16_to_cpu(rec->e_leaf_clusters) * bpc;
1632
1633         if (res->sr_bit_offset < bitoff)
1634                 return 0;
1635         if (res->sr_bit_offset >= (bitoff + bitcount))
1636                 return 0;
1637         res->sr_blkno = le64_to_cpu(rec->e_blkno) +
1638                 (res->sr_bit_offset - bitoff);
1639         if ((res->sr_bit_offset + res->sr_bits) > (bitoff + bitcount))
1640                 res->sr_bits = (bitoff + bitcount) - res->sr_bit_offset;
1641         return 1;
1642 }
1643
1644 static void ocfs2_bg_discontig_fix_result(struct ocfs2_alloc_context *ac,
1645                                           struct ocfs2_group_desc *bg,
1646                                           struct ocfs2_suballoc_result *res)
1647 {
1648         int i;
1649         u64 bg_blkno = res->sr_bg_blkno;  /* Save off */
1650         struct ocfs2_extent_rec *rec;
1651         struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1652         struct ocfs2_chain_list *cl = &di->id2.i_chain;
1653
1654         if (ocfs2_is_cluster_bitmap(ac->ac_inode)) {
1655                 res->sr_blkno = 0;
1656                 return;
1657         }
1658
1659         res->sr_blkno = res->sr_bg_blkno + res->sr_bit_offset;
1660         res->sr_bg_blkno = 0;  /* Clear it for contig block groups */
1661         if (!ocfs2_supports_discontig_bg(OCFS2_SB(ac->ac_inode->i_sb)) ||
1662             !bg->bg_list.l_next_free_rec)
1663                 return;
1664
1665         for (i = 0; i < le16_to_cpu(bg->bg_list.l_next_free_rec); i++) {
1666                 rec = &bg->bg_list.l_recs[i];
1667                 if (ocfs2_bg_discontig_fix_by_rec(res, rec, cl)) {
1668                         res->sr_bg_blkno = bg_blkno;  /* Restore */
1669                         break;
1670                 }
1671         }
1672 }
1673
1674 static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
1675                                   handle_t *handle,
1676                                   u32 bits_wanted,
1677                                   u32 min_bits,
1678                                   struct ocfs2_suballoc_result *res,
1679                                   u16 *bits_left)
1680 {
1681         int ret;
1682         struct buffer_head *group_bh = NULL;
1683         struct ocfs2_group_desc *gd;
1684         struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1685         struct inode *alloc_inode = ac->ac_inode;
1686
1687         ret = ocfs2_read_group_descriptor(alloc_inode, di,
1688                                           res->sr_bg_blkno, &group_bh);
1689         if (ret < 0) {
1690                 mlog_errno(ret);
1691                 return ret;
1692         }
1693
1694         gd = (struct ocfs2_group_desc *) group_bh->b_data;
1695         ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
1696                                   ac->ac_max_block, res);
1697         if (ret < 0) {
1698                 if (ret != -ENOSPC)
1699                         mlog_errno(ret);
1700                 goto out;
1701         }
1702
1703         if (!ret)
1704                 ocfs2_bg_discontig_fix_result(ac, gd, res);
1705
1706         /*
1707          * sr_bg_blkno might have been changed by
1708          * ocfs2_bg_discontig_fix_result
1709          */
1710         res->sr_bg_stable_blkno = group_bh->b_blocknr;
1711
1712         if (ac->ac_find_loc_only)
1713                 goto out_loc_only;
1714
1715         ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
1716                                                res->sr_bits,
1717                                                le16_to_cpu(gd->bg_chain));
1718         if (ret < 0) {
1719                 mlog_errno(ret);
1720                 goto out;
1721         }
1722
1723         ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
1724                                          res->sr_bit_offset, res->sr_bits);
1725         if (ret < 0)
1726                 mlog_errno(ret);
1727
1728 out_loc_only:
1729         *bits_left = le16_to_cpu(gd->bg_free_bits_count);
1730
1731 out:
1732         brelse(group_bh);
1733
1734         return ret;
1735 }
1736
1737 static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
1738                               handle_t *handle,
1739                               u32 bits_wanted,
1740                               u32 min_bits,
1741                               struct ocfs2_suballoc_result *res,
1742                               u16 *bits_left)
1743 {
1744         int status;
1745         u16 chain;
1746         u64 next_group;
1747         struct inode *alloc_inode = ac->ac_inode;
1748         struct buffer_head *group_bh = NULL;
1749         struct buffer_head *prev_group_bh = NULL;
1750         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1751         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1752         struct ocfs2_group_desc *bg;
1753
1754         chain = ac->ac_chain;
1755         trace_ocfs2_search_chain_begin(
1756                 (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
1757                 bits_wanted, chain);
1758
1759         status = ocfs2_read_group_descriptor(alloc_inode, fe,
1760                                              le64_to_cpu(cl->cl_recs[chain].c_blkno),
1761                                              &group_bh);
1762         if (status < 0) {
1763                 mlog_errno(status);
1764                 goto bail;
1765         }
1766         bg = (struct ocfs2_group_desc *) group_bh->b_data;
1767
1768         status = -ENOSPC;
1769         /* for now, the chain search is a bit simplistic. We just use
1770          * the 1st group with any empty bits. */
1771         while ((status = ac->ac_group_search(alloc_inode, group_bh,
1772                                              bits_wanted, min_bits,
1773                                              ac->ac_max_block,
1774                                              res)) == -ENOSPC) {
1775                 if (!bg->bg_next_group)
1776                         break;
1777
1778                 brelse(prev_group_bh);
1779                 prev_group_bh = NULL;
1780
1781                 next_group = le64_to_cpu(bg->bg_next_group);
1782                 prev_group_bh = group_bh;
1783                 group_bh = NULL;
1784                 status = ocfs2_read_group_descriptor(alloc_inode, fe,
1785                                                      next_group, &group_bh);
1786                 if (status < 0) {
1787                         mlog_errno(status);
1788                         goto bail;
1789                 }
1790                 bg = (struct ocfs2_group_desc *) group_bh->b_data;
1791         }
1792         if (status < 0) {
1793                 if (status != -ENOSPC)
1794                         mlog_errno(status);
1795                 goto bail;
1796         }
1797
1798         trace_ocfs2_search_chain_succ(
1799                 (unsigned long long)le64_to_cpu(bg->bg_blkno), res->sr_bits);
1800
1801         res->sr_bg_blkno = le64_to_cpu(bg->bg_blkno);
1802
1803         BUG_ON(res->sr_bits == 0);
1804         if (!status)
1805                 ocfs2_bg_discontig_fix_result(ac, bg, res);
1806
1807         /*
1808          * sr_bg_blkno might have been changed by
1809          * ocfs2_bg_discontig_fix_result
1810          */
1811         res->sr_bg_stable_blkno = group_bh->b_blocknr;
1812
1813         /*
1814          * Keep track of previous block descriptor read. When
1815          * we find a target, if we have read more than X
1816          * number of descriptors, and the target is reasonably
1817          * empty, relink him to top of his chain.
1818          *
1819          * We've read 0 extra blocks and only send one more to
1820          * the transaction, yet the next guy to search has a
1821          * much easier time.
1822          *
1823          * Do this *after* figuring out how many bits we're taking out
1824          * of our target group.
1825          */
1826         if (!ac->ac_disable_chain_relink &&
1827             (prev_group_bh) &&
1828             (ocfs2_block_group_reasonably_empty(bg, res->sr_bits))) {
1829                 status = ocfs2_relink_block_group(handle, alloc_inode,
1830                                                   ac->ac_bh, group_bh,
1831                                                   prev_group_bh, chain);
1832                 if (status < 0) {
1833                         mlog_errno(status);
1834                         goto bail;
1835                 }
1836         }
1837
1838         if (ac->ac_find_loc_only)
1839                 goto out_loc_only;
1840
1841         status = ocfs2_alloc_dinode_update_counts(alloc_inode, handle,
1842                                                   ac->ac_bh, res->sr_bits,
1843                                                   chain);
1844         if (status) {
1845                 mlog_errno(status);
1846                 goto bail;
1847         }
1848
1849         status = ocfs2_block_group_set_bits(handle,
1850                                             alloc_inode,
1851                                             bg,
1852                                             group_bh,
1853                                             res->sr_bit_offset,
1854                                             res->sr_bits);
1855         if (status < 0) {
1856                 mlog_errno(status);
1857                 goto bail;
1858         }
1859
1860         trace_ocfs2_search_chain_end(
1861                         (unsigned long long)le64_to_cpu(fe->i_blkno),
1862                         res->sr_bits);
1863
1864 out_loc_only:
1865         *bits_left = le16_to_cpu(bg->bg_free_bits_count);
1866 bail:
1867         brelse(group_bh);
1868         brelse(prev_group_bh);
1869
1870         if (status)
1871                 mlog_errno(status);
1872         return status;
1873 }
1874
1875 /* will give out up to bits_wanted contiguous bits. */
1876 static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
1877                                      handle_t *handle,
1878                                      u32 bits_wanted,
1879                                      u32 min_bits,
1880                                      struct ocfs2_suballoc_result *res)
1881 {
1882         int status;
1883         u16 victim, i;
1884         u16 bits_left = 0;
1885         u64 hint = ac->ac_last_group;
1886         struct ocfs2_chain_list *cl;
1887         struct ocfs2_dinode *fe;
1888
1889         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1890         BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1891         BUG_ON(!ac->ac_bh);
1892
1893         fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1894
1895         /* The bh was validated by the inode read during
1896          * ocfs2_reserve_suballoc_bits().  Any corruption is a code bug. */
1897         BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
1898
1899         if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1900             le32_to_cpu(fe->id1.bitmap1.i_total)) {
1901                 ocfs2_error(ac->ac_inode->i_sb,
1902                             "Chain allocator dinode %llu has %u used "
1903                             "bits but only %u total.",
1904                             (unsigned long long)le64_to_cpu(fe->i_blkno),
1905                             le32_to_cpu(fe->id1.bitmap1.i_used),
1906                             le32_to_cpu(fe->id1.bitmap1.i_total));
1907                 status = -EIO;
1908                 goto bail;
1909         }
1910
1911         res->sr_bg_blkno = hint;
1912         if (res->sr_bg_blkno) {
1913                 /* Attempt to short-circuit the usual search mechanism
1914                  * by jumping straight to the most recently used
1915                  * allocation group. This helps us maintain some
1916                  * contiguousness across allocations. */
1917                 status = ocfs2_search_one_group(ac, handle, bits_wanted,
1918                                                 min_bits, res, &bits_left);
1919                 if (!status)
1920                         goto set_hint;
1921                 if (status < 0 && status != -ENOSPC) {
1922                         mlog_errno(status);
1923                         goto bail;
1924                 }
1925         }
1926
1927         cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1928
1929         victim = ocfs2_find_victim_chain(cl);
1930         ac->ac_chain = victim;
1931
1932         status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1933                                     res, &bits_left);
1934         if (!status) {
1935                 hint = ocfs2_group_from_res(res);
1936                 goto set_hint;
1937         }
1938         if (status < 0 && status != -ENOSPC) {
1939                 mlog_errno(status);
1940                 goto bail;
1941         }
1942
1943         trace_ocfs2_claim_suballoc_bits(victim);
1944
1945         /* If we didn't pick a good victim, then just default to
1946          * searching each chain in order. Don't allow chain relinking
1947          * because we only calculate enough journal credits for one
1948          * relink per alloc. */
1949         ac->ac_disable_chain_relink = 1;
1950         for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
1951                 if (i == victim)
1952                         continue;
1953                 if (!cl->cl_recs[i].c_free)
1954                         continue;
1955
1956                 ac->ac_chain = i;
1957                 status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1958                                             res, &bits_left);
1959                 if (!status) {
1960                         hint = ocfs2_group_from_res(res);
1961                         break;
1962                 }
1963                 if (status < 0 && status != -ENOSPC) {
1964                         mlog_errno(status);
1965                         goto bail;
1966                 }
1967         }
1968
1969 set_hint:
1970         if (status != -ENOSPC) {
1971                 /* If the next search of this group is not likely to
1972                  * yield a suitable extent, then we reset the last
1973                  * group hint so as to not waste a disk read */
1974                 if (bits_left < min_bits)
1975                         ac->ac_last_group = 0;
1976                 else
1977                         ac->ac_last_group = hint;
1978         }
1979
1980 bail:
1981         if (status)
1982                 mlog_errno(status);
1983         return status;
1984 }
1985
1986 int ocfs2_claim_metadata(handle_t *handle,
1987                          struct ocfs2_alloc_context *ac,
1988                          u32 bits_wanted,
1989                          u64 *suballoc_loc,
1990                          u16 *suballoc_bit_start,
1991                          unsigned int *num_bits,
1992                          u64 *blkno_start)
1993 {
1994         int status;
1995         struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
1996
1997         BUG_ON(!ac);
1998         BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
1999         BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
2000
2001         status = ocfs2_claim_suballoc_bits(ac,
2002                                            handle,
2003                                            bits_wanted,
2004                                            1,
2005                                            &res);
2006         if (status < 0) {
2007                 mlog_errno(status);
2008                 goto bail;
2009         }
2010         atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2011
2012         *suballoc_loc = res.sr_bg_blkno;
2013         *suballoc_bit_start = res.sr_bit_offset;
2014         *blkno_start = res.sr_blkno;
2015         ac->ac_bits_given += res.sr_bits;
2016         *num_bits = res.sr_bits;
2017         status = 0;
2018 bail:
2019         if (status)
2020                 mlog_errno(status);
2021         return status;
2022 }
2023
2024 static void ocfs2_init_inode_ac_group(struct inode *dir,
2025                                       struct buffer_head *parent_di_bh,
2026                                       struct ocfs2_alloc_context *ac)
2027 {
2028         struct ocfs2_dinode *di = (struct ocfs2_dinode *)parent_di_bh->b_data;
2029         /*
2030          * Try to allocate inodes from some specific group.
2031          *
2032          * If the parent dir has recorded the last group used in allocation,
2033          * cool, use it. Otherwise if we try to allocate new inode from the
2034          * same slot the parent dir belongs to, use the same chunk.
2035          *
2036          * We are very careful here to avoid the mistake of setting
2037          * ac_last_group to a group descriptor from a different (unlocked) slot.
2038          */
2039         if (OCFS2_I(dir)->ip_last_used_group &&
2040             OCFS2_I(dir)->ip_last_used_slot == ac->ac_alloc_slot)
2041                 ac->ac_last_group = OCFS2_I(dir)->ip_last_used_group;
2042         else if (le16_to_cpu(di->i_suballoc_slot) == ac->ac_alloc_slot) {
2043                 if (di->i_suballoc_loc)
2044                         ac->ac_last_group = le64_to_cpu(di->i_suballoc_loc);
2045                 else
2046                         ac->ac_last_group = ocfs2_which_suballoc_group(
2047                                         le64_to_cpu(di->i_blkno),
2048                                         le16_to_cpu(di->i_suballoc_bit));
2049         }
2050 }
2051
2052 static inline void ocfs2_save_inode_ac_group(struct inode *dir,
2053                                              struct ocfs2_alloc_context *ac)
2054 {
2055         OCFS2_I(dir)->ip_last_used_group = ac->ac_last_group;
2056         OCFS2_I(dir)->ip_last_used_slot = ac->ac_alloc_slot;
2057 }
2058
2059 int ocfs2_find_new_inode_loc(struct inode *dir,
2060                              struct buffer_head *parent_fe_bh,
2061                              struct ocfs2_alloc_context *ac,
2062                              u64 *fe_blkno)
2063 {
2064         int ret;
2065         handle_t *handle = NULL;
2066         struct ocfs2_suballoc_result *res;
2067
2068         BUG_ON(!ac);
2069         BUG_ON(ac->ac_bits_given != 0);
2070         BUG_ON(ac->ac_bits_wanted != 1);
2071         BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2072
2073         res = kzalloc(sizeof(*res), GFP_NOFS);
2074         if (res == NULL) {
2075                 ret = -ENOMEM;
2076                 mlog_errno(ret);
2077                 goto out;
2078         }
2079
2080         ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2081
2082         /*
2083          * The handle started here is for chain relink. Alternatively,
2084          * we could just disable relink for these calls.
2085          */
2086         handle = ocfs2_start_trans(OCFS2_SB(dir->i_sb), OCFS2_SUBALLOC_ALLOC);
2087         if (IS_ERR(handle)) {
2088                 ret = PTR_ERR(handle);
2089                 handle = NULL;
2090                 mlog_errno(ret);
2091                 goto out;
2092         }
2093
2094         /*
2095          * This will instruct ocfs2_claim_suballoc_bits and
2096          * ocfs2_search_one_group to search but save actual allocation
2097          * for later.
2098          */
2099         ac->ac_find_loc_only = 1;
2100
2101         ret = ocfs2_claim_suballoc_bits(ac, handle, 1, 1, res);
2102         if (ret < 0) {
2103                 mlog_errno(ret);
2104                 goto out;
2105         }
2106
2107         ac->ac_find_loc_priv = res;
2108         *fe_blkno = res->sr_blkno;
2109
2110 out:
2111         if (handle)
2112                 ocfs2_commit_trans(OCFS2_SB(dir->i_sb), handle);
2113
2114         if (ret)
2115                 kfree(res);
2116
2117         return ret;
2118 }
2119
2120 int ocfs2_claim_new_inode_at_loc(handle_t *handle,
2121                                  struct inode *dir,
2122                                  struct ocfs2_alloc_context *ac,
2123                                  u64 *suballoc_loc,
2124                                  u16 *suballoc_bit,
2125                                  u64 di_blkno)
2126 {
2127         int ret;
2128         u16 chain;
2129         struct ocfs2_suballoc_result *res = ac->ac_find_loc_priv;
2130         struct buffer_head *bg_bh = NULL;
2131         struct ocfs2_group_desc *bg;
2132         struct ocfs2_dinode *di = (struct ocfs2_dinode *) ac->ac_bh->b_data;
2133
2134         /*
2135          * Since di_blkno is being passed back in, we check for any
2136          * inconsistencies which may have happened between
2137          * calls. These are code bugs as di_blkno is not expected to
2138          * change once returned from ocfs2_find_new_inode_loc()
2139          */
2140         BUG_ON(res->sr_blkno != di_blkno);
2141
2142         ret = ocfs2_read_group_descriptor(ac->ac_inode, di,
2143                                           res->sr_bg_stable_blkno, &bg_bh);
2144         if (ret) {
2145                 mlog_errno(ret);
2146                 goto out;
2147         }
2148
2149         bg = (struct ocfs2_group_desc *) bg_bh->b_data;
2150         chain = le16_to_cpu(bg->bg_chain);
2151
2152         ret = ocfs2_alloc_dinode_update_counts(ac->ac_inode, handle,
2153                                                ac->ac_bh, res->sr_bits,
2154                                                chain);
2155         if (ret) {
2156                 mlog_errno(ret);
2157                 goto out;
2158         }
2159
2160         ret = ocfs2_block_group_set_bits(handle,
2161                                          ac->ac_inode,
2162                                          bg,
2163                                          bg_bh,
2164                                          res->sr_bit_offset,
2165                                          res->sr_bits);
2166         if (ret < 0) {
2167                 mlog_errno(ret);
2168                 goto out;
2169         }
2170
2171         trace_ocfs2_claim_new_inode_at_loc((unsigned long long)di_blkno,
2172                                            res->sr_bits);
2173
2174         atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2175
2176         BUG_ON(res->sr_bits != 1);
2177
2178         *suballoc_loc = res->sr_bg_blkno;
2179         *suballoc_bit = res->sr_bit_offset;
2180         ac->ac_bits_given++;
2181         ocfs2_save_inode_ac_group(dir, ac);
2182
2183 out:
2184         brelse(bg_bh);
2185
2186         return ret;
2187 }
2188
2189 int ocfs2_claim_new_inode(handle_t *handle,
2190                           struct inode *dir,
2191                           struct buffer_head *parent_fe_bh,
2192                           struct ocfs2_alloc_context *ac,
2193                           u64 *suballoc_loc,
2194                           u16 *suballoc_bit,
2195                           u64 *fe_blkno)
2196 {
2197         int status;
2198         struct ocfs2_suballoc_result res;
2199
2200         BUG_ON(!ac);
2201         BUG_ON(ac->ac_bits_given != 0);
2202         BUG_ON(ac->ac_bits_wanted != 1);
2203         BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2204
2205         ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2206
2207         status = ocfs2_claim_suballoc_bits(ac,
2208                                            handle,
2209                                            1,
2210                                            1,
2211                                            &res);
2212         if (status < 0) {
2213                 mlog_errno(status);
2214                 goto bail;
2215         }
2216         atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2217
2218         BUG_ON(res.sr_bits != 1);
2219
2220         *suballoc_loc = res.sr_bg_blkno;
2221         *suballoc_bit = res.sr_bit_offset;
2222         *fe_blkno = res.sr_blkno;
2223         ac->ac_bits_given++;
2224         ocfs2_save_inode_ac_group(dir, ac);
2225         status = 0;
2226 bail:
2227         if (status)
2228                 mlog_errno(status);
2229         return status;
2230 }
2231
2232 /* translate a group desc. blkno and it's bitmap offset into
2233  * disk cluster offset. */
2234 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
2235                                                    u64 bg_blkno,
2236                                                    u16 bg_bit_off)
2237 {
2238         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2239         u32 cluster = 0;
2240
2241         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2242
2243         if (bg_blkno != osb->first_cluster_group_blkno)
2244                 cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
2245         cluster += (u32) bg_bit_off;
2246         return cluster;
2247 }
2248
2249 /* given a cluster offset, calculate which block group it belongs to
2250  * and return that block offset. */
2251 u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster)
2252 {
2253         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2254         u32 group_no;
2255
2256         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2257
2258         group_no = cluster / osb->bitmap_cpg;
2259         if (!group_no)
2260                 return osb->first_cluster_group_blkno;
2261         return ocfs2_clusters_to_blocks(inode->i_sb,
2262                                         group_no * osb->bitmap_cpg);
2263 }
2264
2265 /* given the block number of a cluster start, calculate which cluster
2266  * group and descriptor bitmap offset that corresponds to. */
2267 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
2268                                                 u64 data_blkno,
2269                                                 u64 *bg_blkno,
2270                                                 u16 *bg_bit_off)
2271 {
2272         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2273         u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
2274
2275         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2276
2277         *bg_blkno = ocfs2_which_cluster_group(inode,
2278                                               data_cluster);
2279
2280         if (*bg_blkno == osb->first_cluster_group_blkno)
2281                 *bg_bit_off = (u16) data_cluster;
2282         else
2283                 *bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
2284                                                              data_blkno - *bg_blkno);
2285 }
2286
2287 /*
2288  * min_bits - minimum contiguous chunk from this total allocation we
2289  * can handle. set to what we asked for originally for a full
2290  * contig. allocation, set to '1' to indicate we can deal with extents
2291  * of any size.
2292  */
2293 int __ocfs2_claim_clusters(handle_t *handle,
2294                            struct ocfs2_alloc_context *ac,
2295                            u32 min_clusters,
2296                            u32 max_clusters,
2297                            u32 *cluster_start,
2298                            u32 *num_clusters)
2299 {
2300         int status;
2301         unsigned int bits_wanted = max_clusters;
2302         struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
2303         struct ocfs2_super *osb = OCFS2_SB(ac->ac_inode->i_sb);
2304
2305         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
2306
2307         BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
2308                && ac->ac_which != OCFS2_AC_USE_MAIN);
2309
2310         if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
2311                 WARN_ON(min_clusters > 1);
2312
2313                 status = ocfs2_claim_local_alloc_bits(osb,
2314                                                       handle,
2315                                                       ac,
2316                                                       bits_wanted,
2317                                                       cluster_start,
2318                                                       num_clusters);
2319                 if (!status)
2320                         atomic_inc(&osb->alloc_stats.local_data);
2321         } else {
2322                 if (min_clusters > (osb->bitmap_cpg - 1)) {
2323                         /* The only paths asking for contiguousness
2324                          * should know about this already. */
2325                         mlog(ML_ERROR, "minimum allocation requested %u exceeds "
2326                              "group bitmap size %u!\n", min_clusters,
2327                              osb->bitmap_cpg);
2328                         status = -ENOSPC;
2329                         goto bail;
2330                 }
2331                 /* clamp the current request down to a realistic size. */
2332                 if (bits_wanted > (osb->bitmap_cpg - 1))
2333                         bits_wanted = osb->bitmap_cpg - 1;
2334
2335                 status = ocfs2_claim_suballoc_bits(ac,
2336                                                    handle,
2337                                                    bits_wanted,
2338                                                    min_clusters,
2339                                                    &res);
2340                 if (!status) {
2341                         BUG_ON(res.sr_blkno); /* cluster alloc can't set */
2342                         *cluster_start =
2343                                 ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
2344                                                                  res.sr_bg_blkno,
2345                                                                  res.sr_bit_offset);
2346                         atomic_inc(&osb->alloc_stats.bitmap_data);
2347                         *num_clusters = res.sr_bits;
2348                 }
2349         }
2350         if (status < 0) {
2351                 if (status != -ENOSPC)
2352                         mlog_errno(status);
2353                 goto bail;
2354         }
2355
2356         ac->ac_bits_given += *num_clusters;
2357
2358 bail:
2359         if (status)
2360                 mlog_errno(status);
2361         return status;
2362 }
2363
2364 int ocfs2_claim_clusters(handle_t *handle,
2365                          struct ocfs2_alloc_context *ac,
2366                          u32 min_clusters,
2367                          u32 *cluster_start,
2368                          u32 *num_clusters)
2369 {
2370         unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
2371
2372         return __ocfs2_claim_clusters(handle, ac, min_clusters,
2373                                       bits_wanted, cluster_start, num_clusters);
2374 }
2375
2376 static int ocfs2_block_group_clear_bits(handle_t *handle,
2377                                         struct inode *alloc_inode,
2378                                         struct ocfs2_group_desc *bg,
2379                                         struct buffer_head *group_bh,
2380                                         unsigned int bit_off,
2381                                         unsigned int num_bits,
2382                                         void (*undo_fn)(unsigned int bit,
2383                                                         unsigned long *bmap))
2384 {
2385         int status;
2386         unsigned int tmp;
2387         struct ocfs2_group_desc *undo_bg = NULL;
2388
2389         /* The caller got this descriptor from
2390          * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
2391         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
2392
2393         trace_ocfs2_block_group_clear_bits(bit_off, num_bits);
2394
2395         BUG_ON(undo_fn && !ocfs2_is_cluster_bitmap(alloc_inode));
2396         status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
2397                                          group_bh,
2398                                          undo_fn ?
2399                                          OCFS2_JOURNAL_ACCESS_UNDO :
2400                                          OCFS2_JOURNAL_ACCESS_WRITE);
2401         if (status < 0) {
2402                 mlog_errno(status);
2403                 goto bail;
2404         }
2405
2406         if (undo_fn) {
2407                 jbd_lock_bh_state(group_bh);
2408                 undo_bg = (struct ocfs2_group_desc *)
2409                                         bh2jh(group_bh)->b_committed_data;
2410                 BUG_ON(!undo_bg);
2411         }
2412
2413         tmp = num_bits;
2414         while(tmp--) {
2415                 ocfs2_clear_bit((bit_off + tmp),
2416                                 (unsigned long *) bg->bg_bitmap);
2417                 if (undo_fn)
2418                         undo_fn(bit_off + tmp,
2419                                 (unsigned long *) undo_bg->bg_bitmap);
2420         }
2421         le16_add_cpu(&bg->bg_free_bits_count, num_bits);
2422         if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
2423                 ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit"
2424                             " count %u but claims %u are freed. num_bits %d",
2425                             (unsigned long long)le64_to_cpu(bg->bg_blkno),
2426                             le16_to_cpu(bg->bg_bits),
2427                             le16_to_cpu(bg->bg_free_bits_count), num_bits);
2428                 return -EROFS;
2429         }
2430
2431         if (undo_fn)
2432                 jbd_unlock_bh_state(group_bh);
2433
2434         ocfs2_journal_dirty(handle, group_bh);
2435 bail:
2436         return status;
2437 }
2438
2439 /*
2440  * expects the suballoc inode to already be locked.
2441  */
2442 static int _ocfs2_free_suballoc_bits(handle_t *handle,
2443                                      struct inode *alloc_inode,
2444                                      struct buffer_head *alloc_bh,
2445                                      unsigned int start_bit,
2446                                      u64 bg_blkno,
2447                                      unsigned int count,
2448                                      void (*undo_fn)(unsigned int bit,
2449                                                      unsigned long *bitmap))
2450 {
2451         int status = 0;
2452         u32 tmp_used;
2453         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
2454         struct ocfs2_chain_list *cl = &fe->id2.i_chain;
2455         struct buffer_head *group_bh = NULL;
2456         struct ocfs2_group_desc *group;
2457
2458         /* The alloc_bh comes from ocfs2_free_dinode() or
2459          * ocfs2_free_clusters().  The callers have all locked the
2460          * allocator and gotten alloc_bh from the lock call.  This
2461          * validates the dinode buffer.  Any corruption that has happened
2462          * is a code bug. */
2463         BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
2464         BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
2465
2466         trace_ocfs2_free_suballoc_bits(
2467                 (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
2468                 (unsigned long long)bg_blkno,
2469                 start_bit, count);
2470
2471         status = ocfs2_read_group_descriptor(alloc_inode, fe, bg_blkno,
2472                                              &group_bh);
2473         if (status < 0) {
2474                 mlog_errno(status);
2475                 goto bail;
2476         }
2477         group = (struct ocfs2_group_desc *) group_bh->b_data;
2478
2479         BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
2480
2481         status = ocfs2_block_group_clear_bits(handle, alloc_inode,
2482                                               group, group_bh,
2483                                               start_bit, count, undo_fn);
2484         if (status < 0) {
2485                 mlog_errno(status);
2486                 goto bail;
2487         }
2488
2489         status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
2490                                          alloc_bh, OCFS2_JOURNAL_ACCESS_WRITE);
2491         if (status < 0) {
2492                 mlog_errno(status);
2493                 goto bail;
2494         }
2495
2496         le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
2497                      count);
2498         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
2499         fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
2500         ocfs2_journal_dirty(handle, alloc_bh);
2501
2502 bail:
2503         brelse(group_bh);
2504
2505         if (status)
2506                 mlog_errno(status);
2507         return status;
2508 }
2509
2510 int ocfs2_free_suballoc_bits(handle_t *handle,
2511                              struct inode *alloc_inode,
2512                              struct buffer_head *alloc_bh,
2513                              unsigned int start_bit,
2514                              u64 bg_blkno,
2515                              unsigned int count)
2516 {
2517         return _ocfs2_free_suballoc_bits(handle, alloc_inode, alloc_bh,
2518                                          start_bit, bg_blkno, count, NULL);
2519 }
2520
2521 int ocfs2_free_dinode(handle_t *handle,
2522                       struct inode *inode_alloc_inode,
2523                       struct buffer_head *inode_alloc_bh,
2524                       struct ocfs2_dinode *di)
2525 {
2526         u64 blk = le64_to_cpu(di->i_blkno);
2527         u16 bit = le16_to_cpu(di->i_suballoc_bit);
2528         u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
2529
2530         if (di->i_suballoc_loc)
2531                 bg_blkno = le64_to_cpu(di->i_suballoc_loc);
2532         return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
2533                                         inode_alloc_bh, bit, bg_blkno, 1);
2534 }
2535
2536 static int _ocfs2_free_clusters(handle_t *handle,
2537                                 struct inode *bitmap_inode,
2538                                 struct buffer_head *bitmap_bh,
2539                                 u64 start_blk,
2540                                 unsigned int num_clusters,
2541                                 void (*undo_fn)(unsigned int bit,
2542                                                 unsigned long *bitmap))
2543 {
2544         int status;
2545         u16 bg_start_bit;
2546         u64 bg_blkno;
2547         struct ocfs2_dinode *fe;
2548
2549         /* You can't ever have a contiguous set of clusters
2550          * bigger than a block group bitmap so we never have to worry
2551          * about looping on them.
2552          * This is expensive. We can safely remove once this stuff has
2553          * gotten tested really well. */
2554         BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb, ocfs2_blocks_to_clusters(bitmap_inode->i_sb, start_blk)));
2555
2556         fe = (struct ocfs2_dinode *) bitmap_bh->b_data;
2557
2558         ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
2559                                      &bg_start_bit);
2560
2561         trace_ocfs2_free_clusters((unsigned long long)bg_blkno,
2562                         (unsigned long long)start_blk,
2563                         bg_start_bit, num_clusters);
2564
2565         status = _ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
2566                                            bg_start_bit, bg_blkno,
2567                                            num_clusters, undo_fn);
2568         if (status < 0) {
2569                 mlog_errno(status);
2570                 goto out;
2571         }
2572
2573         ocfs2_local_alloc_seen_free_bits(OCFS2_SB(bitmap_inode->i_sb),
2574                                          num_clusters);
2575
2576 out:
2577         if (status)
2578                 mlog_errno(status);
2579         return status;
2580 }
2581
2582 int ocfs2_free_clusters(handle_t *handle,
2583                         struct inode *bitmap_inode,
2584                         struct buffer_head *bitmap_bh,
2585                         u64 start_blk,
2586                         unsigned int num_clusters)
2587 {
2588         return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2589                                     start_blk, num_clusters,
2590                                     _ocfs2_set_bit);
2591 }
2592
2593 /*
2594  * Give never-used clusters back to the global bitmap.  We don't need
2595  * to protect these bits in the undo buffer.
2596  */
2597 int ocfs2_release_clusters(handle_t *handle,
2598                            struct inode *bitmap_inode,
2599                            struct buffer_head *bitmap_bh,
2600                            u64 start_blk,
2601                            unsigned int num_clusters)
2602 {
2603         return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2604                                     start_blk, num_clusters,
2605                                     _ocfs2_clear_bit);
2606 }
2607
2608 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg)
2609 {
2610         printk("Block Group:\n");
2611         printk("bg_signature:       %s\n", bg->bg_signature);
2612         printk("bg_size:            %u\n", bg->bg_size);
2613         printk("bg_bits:            %u\n", bg->bg_bits);
2614         printk("bg_free_bits_count: %u\n", bg->bg_free_bits_count);
2615         printk("bg_chain:           %u\n", bg->bg_chain);
2616         printk("bg_generation:      %u\n", le32_to_cpu(bg->bg_generation));
2617         printk("bg_next_group:      %llu\n",
2618                (unsigned long long)bg->bg_next_group);
2619         printk("bg_parent_dinode:   %llu\n",
2620                (unsigned long long)bg->bg_parent_dinode);
2621         printk("bg_blkno:           %llu\n",
2622                (unsigned long long)bg->bg_blkno);
2623 }
2624
2625 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe)
2626 {
2627         int i;
2628
2629         printk("Suballoc Inode %llu:\n", (unsigned long long)fe->i_blkno);
2630         printk("i_signature:                  %s\n", fe->i_signature);
2631         printk("i_size:                       %llu\n",
2632                (unsigned long long)fe->i_size);
2633         printk("i_clusters:                   %u\n", fe->i_clusters);
2634         printk("i_generation:                 %u\n",
2635                le32_to_cpu(fe->i_generation));
2636         printk("id1.bitmap1.i_used:           %u\n",
2637                le32_to_cpu(fe->id1.bitmap1.i_used));
2638         printk("id1.bitmap1.i_total:          %u\n",
2639                le32_to_cpu(fe->id1.bitmap1.i_total));
2640         printk("id2.i_chain.cl_cpg:           %u\n", fe->id2.i_chain.cl_cpg);
2641         printk("id2.i_chain.cl_bpc:           %u\n", fe->id2.i_chain.cl_bpc);
2642         printk("id2.i_chain.cl_count:         %u\n", fe->id2.i_chain.cl_count);
2643         printk("id2.i_chain.cl_next_free_rec: %u\n",
2644                fe->id2.i_chain.cl_next_free_rec);
2645         for(i = 0; i < fe->id2.i_chain.cl_next_free_rec; i++) {
2646                 printk("fe->id2.i_chain.cl_recs[%d].c_free:  %u\n", i,
2647                        fe->id2.i_chain.cl_recs[i].c_free);
2648                 printk("fe->id2.i_chain.cl_recs[%d].c_total: %u\n", i,
2649                        fe->id2.i_chain.cl_recs[i].c_total);
2650                 printk("fe->id2.i_chain.cl_recs[%d].c_blkno: %llu\n", i,
2651                        (unsigned long long)fe->id2.i_chain.cl_recs[i].c_blkno);
2652         }
2653 }
2654
2655 /*
2656  * For a given allocation, determine which allocators will need to be
2657  * accessed, and lock them, reserving the appropriate number of bits.
2658  *
2659  * Sparse file systems call this from ocfs2_write_begin_nolock()
2660  * and ocfs2_allocate_unwritten_extents().
2661  *
2662  * File systems which don't support holes call this from
2663  * ocfs2_extend_allocation().
2664  */
2665 int ocfs2_lock_allocators(struct inode *inode,
2666                           struct ocfs2_extent_tree *et,
2667                           u32 clusters_to_add, u32 extents_to_split,
2668                           struct ocfs2_alloc_context **data_ac,
2669                           struct ocfs2_alloc_context **meta_ac)
2670 {
2671         int ret = 0, num_free_extents;
2672         unsigned int max_recs_needed = clusters_to_add + 2 * extents_to_split;
2673         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2674
2675         *meta_ac = NULL;
2676         if (data_ac)
2677                 *data_ac = NULL;
2678
2679         BUG_ON(clusters_to_add != 0 && data_ac == NULL);
2680
2681         num_free_extents = ocfs2_num_free_extents(osb, et);
2682         if (num_free_extents < 0) {
2683                 ret = num_free_extents;
2684                 mlog_errno(ret);
2685                 goto out;
2686         }
2687
2688         /*
2689          * Sparse allocation file systems need to be more conservative
2690          * with reserving room for expansion - the actual allocation
2691          * happens while we've got a journal handle open so re-taking
2692          * a cluster lock (because we ran out of room for another
2693          * extent) will violate ordering rules.
2694          *
2695          * Most of the time we'll only be seeing this 1 cluster at a time
2696          * anyway.
2697          *
2698          * Always lock for any unwritten extents - we might want to
2699          * add blocks during a split.
2700          */
2701         if (!num_free_extents ||
2702             (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed)) {
2703                 ret = ocfs2_reserve_new_metadata(osb, et->et_root_el, meta_ac);
2704                 if (ret < 0) {
2705                         if (ret != -ENOSPC)
2706                                 mlog_errno(ret);
2707                         goto out;
2708                 }
2709         }
2710
2711         if (clusters_to_add == 0)
2712                 goto out;
2713
2714         ret = ocfs2_reserve_clusters(osb, clusters_to_add, data_ac);
2715         if (ret < 0) {
2716                 if (ret != -ENOSPC)
2717                         mlog_errno(ret);
2718                 goto out;
2719         }
2720
2721 out:
2722         if (ret) {
2723                 if (*meta_ac) {
2724                         ocfs2_free_alloc_context(*meta_ac);
2725                         *meta_ac = NULL;
2726                 }
2727
2728                 /*
2729                  * We cannot have an error and a non null *data_ac.
2730                  */
2731         }
2732
2733         return ret;
2734 }
2735
2736 /*
2737  * Read the inode specified by blkno to get suballoc_slot and
2738  * suballoc_bit.
2739  */
2740 static int ocfs2_get_suballoc_slot_bit(struct ocfs2_super *osb, u64 blkno,
2741                                        u16 *suballoc_slot, u64 *group_blkno,
2742                                        u16 *suballoc_bit)
2743 {
2744         int status;
2745         struct buffer_head *inode_bh = NULL;
2746         struct ocfs2_dinode *inode_fe;
2747
2748         trace_ocfs2_get_suballoc_slot_bit((unsigned long long)blkno);
2749
2750         /* dirty read disk */
2751         status = ocfs2_read_blocks_sync(osb, blkno, 1, &inode_bh);
2752         if (status < 0) {
2753                 mlog(ML_ERROR, "read block %llu failed %d\n",
2754                      (unsigned long long)blkno, status);
2755                 goto bail;
2756         }
2757
2758         inode_fe = (struct ocfs2_dinode *) inode_bh->b_data;
2759         if (!OCFS2_IS_VALID_DINODE(inode_fe)) {
2760                 mlog(ML_ERROR, "invalid inode %llu requested\n",
2761                      (unsigned long long)blkno);
2762                 status = -EINVAL;
2763                 goto bail;
2764         }
2765
2766         if (le16_to_cpu(inode_fe->i_suballoc_slot) != (u16)OCFS2_INVALID_SLOT &&
2767             (u32)le16_to_cpu(inode_fe->i_suballoc_slot) > osb->max_slots - 1) {
2768                 mlog(ML_ERROR, "inode %llu has invalid suballoc slot %u\n",
2769                      (unsigned long long)blkno,
2770                      (u32)le16_to_cpu(inode_fe->i_suballoc_slot));
2771                 status = -EINVAL;
2772                 goto bail;
2773         }
2774
2775         if (suballoc_slot)
2776                 *suballoc_slot = le16_to_cpu(inode_fe->i_suballoc_slot);
2777         if (suballoc_bit)
2778                 *suballoc_bit = le16_to_cpu(inode_fe->i_suballoc_bit);
2779         if (group_blkno)
2780                 *group_blkno = le64_to_cpu(inode_fe->i_suballoc_loc);
2781
2782 bail:
2783         brelse(inode_bh);
2784
2785         if (status)
2786                 mlog_errno(status);
2787         return status;
2788 }
2789
2790 /*
2791  * test whether bit is SET in allocator bitmap or not.  on success, 0
2792  * is returned and *res is 1 for SET; 0 otherwise.  when fails, errno
2793  * is returned and *res is meaningless.  Call this after you have
2794  * cluster locked against suballoc, or you may get a result based on
2795  * non-up2date contents
2796  */
2797 static int ocfs2_test_suballoc_bit(struct ocfs2_super *osb,
2798                                    struct inode *suballoc,
2799                                    struct buffer_head *alloc_bh,
2800                                    u64 group_blkno, u64 blkno,
2801                                    u16 bit, int *res)
2802 {
2803         struct ocfs2_dinode *alloc_di;
2804         struct ocfs2_group_desc *group;
2805         struct buffer_head *group_bh = NULL;
2806         u64 bg_blkno;
2807         int status;
2808
2809         trace_ocfs2_test_suballoc_bit((unsigned long long)blkno,
2810                                       (unsigned int)bit);
2811
2812         alloc_di = (struct ocfs2_dinode *)alloc_bh->b_data;
2813         if ((bit + 1) > ocfs2_bits_per_group(&alloc_di->id2.i_chain)) {
2814                 mlog(ML_ERROR, "suballoc bit %u out of range of %u\n",
2815                      (unsigned int)bit,
2816                      ocfs2_bits_per_group(&alloc_di->id2.i_chain));
2817                 status = -EINVAL;
2818                 goto bail;
2819         }
2820
2821         bg_blkno = group_blkno ? group_blkno :
2822                    ocfs2_which_suballoc_group(blkno, bit);
2823         status = ocfs2_read_group_descriptor(suballoc, alloc_di, bg_blkno,
2824                                              &group_bh);
2825         if (status < 0) {
2826                 mlog(ML_ERROR, "read group %llu failed %d\n",
2827                      (unsigned long long)bg_blkno, status);
2828                 goto bail;
2829         }
2830
2831         group = (struct ocfs2_group_desc *) group_bh->b_data;
2832         *res = ocfs2_test_bit(bit, (unsigned long *)group->bg_bitmap);
2833
2834 bail:
2835         brelse(group_bh);
2836
2837         if (status)
2838                 mlog_errno(status);
2839         return status;
2840 }
2841
2842 /*
2843  * Test if the bit representing this inode (blkno) is set in the
2844  * suballocator.
2845  *
2846  * On success, 0 is returned and *res is 1 for SET; 0 otherwise.
2847  *
2848  * In the event of failure, a negative value is returned and *res is
2849  * meaningless.
2850  *
2851  * Callers must make sure to hold nfs_sync_lock to prevent
2852  * ocfs2_delete_inode() on another node from accessing the same
2853  * suballocator concurrently.
2854  */
2855 int ocfs2_test_inode_bit(struct ocfs2_super *osb, u64 blkno, int *res)
2856 {
2857         int status;
2858         u64 group_blkno = 0;
2859         u16 suballoc_bit = 0, suballoc_slot = 0;
2860         struct inode *inode_alloc_inode;
2861         struct buffer_head *alloc_bh = NULL;
2862
2863         trace_ocfs2_test_inode_bit((unsigned long long)blkno);
2864
2865         status = ocfs2_get_suballoc_slot_bit(osb, blkno, &suballoc_slot,
2866                                              &group_blkno, &suballoc_bit);
2867         if (status < 0) {
2868                 mlog(ML_ERROR, "get alloc slot and bit failed %d\n", status);
2869                 goto bail;
2870         }
2871
2872         inode_alloc_inode =
2873                 ocfs2_get_system_file_inode(osb, INODE_ALLOC_SYSTEM_INODE,
2874                                             suballoc_slot);
2875         if (!inode_alloc_inode) {
2876                 /* the error code could be inaccurate, but we are not able to
2877                  * get the correct one. */
2878                 status = -EINVAL;
2879                 mlog(ML_ERROR, "unable to get alloc inode in slot %u\n",
2880                      (u32)suballoc_slot);
2881                 goto bail;
2882         }
2883
2884         mutex_lock(&inode_alloc_inode->i_mutex);
2885         status = ocfs2_inode_lock(inode_alloc_inode, &alloc_bh, 0);
2886         if (status < 0) {
2887                 mutex_unlock(&inode_alloc_inode->i_mutex);
2888                 mlog(ML_ERROR, "lock on alloc inode on slot %u failed %d\n",
2889                      (u32)suballoc_slot, status);
2890                 goto bail;
2891         }
2892
2893         status = ocfs2_test_suballoc_bit(osb, inode_alloc_inode, alloc_bh,
2894                                          group_blkno, blkno, suballoc_bit, res);
2895         if (status < 0)
2896                 mlog(ML_ERROR, "test suballoc bit failed %d\n", status);
2897
2898         ocfs2_inode_unlock(inode_alloc_inode, 0);
2899         mutex_unlock(&inode_alloc_inode->i_mutex);
2900
2901         iput(inode_alloc_inode);
2902         brelse(alloc_bh);
2903 bail:
2904         if (status)
2905                 mlog_errno(status);
2906         return status;
2907 }