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 #define MLOG_MASK_PREFIX ML_DISK_ALLOC
  33 #include <cluster/masklog.h>
  34
  35 #include "ocfs2.h"
  36
  37 #include "alloc.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
  47 #include "buffer_head_io.h"
  48
  49 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg);
  50 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe);
  51 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl);
  52 static int ocfs2_block_group_fill(handle_t *handle,
  53                                   struct inode *alloc_inode,
  54                                   struct buffer_head *bg_bh,
  55                                   u64 group_blkno,
  56                                   u16 my_chain,
  57                                   struct ocfs2_chain_list *cl);
  58 static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
  59                                    struct inode *alloc_inode,
  60                                    struct buffer_head *bh);
  61
  62 static int ocfs2_cluster_group_search(struct inode *inode,
  63                                       struct buffer_head *group_bh,
  64                                       u32 bits_wanted, u32 min_bits,
  65                                       u16 *bit_off, u16 *bits_found);
  66 static int ocfs2_block_group_search(struct inode *inode,
  67                                     struct buffer_head *group_bh,
  68                                     u32 bits_wanted, u32 min_bits,
  69                                     u16 *bit_off, u16 *bits_found);
  70 static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
  71                                      struct ocfs2_alloc_context *ac,
  72                                      handle_t *handle,
  73                                      u32 bits_wanted,
  74                                      u32 min_bits,
  75                                      u16 *bit_off,
  76                                      unsigned int *num_bits,
  77                                      u64 *bg_blkno);
  78 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
  79                                          int nr);
  80 static inline int ocfs2_block_group_set_bits(handle_t *handle,
  81                                              struct inode *alloc_inode,
  82                                              struct ocfs2_group_desc *bg,
  83                                              struct buffer_head *group_bh,
  84                                              unsigned int bit_off,
  85                                              unsigned int num_bits);
  86 static inline int ocfs2_block_group_clear_bits(handle_t *handle,
  87                                                struct inode *alloc_inode,
  88                                                struct ocfs2_group_desc *bg,
  89                                                struct buffer_head *group_bh,
  90                                                unsigned int bit_off,
  91                                                unsigned int num_bits);
  92
  93 static int ocfs2_relink_block_group(handle_t *handle,
  94                                     struct inode *alloc_inode,
  95                                     struct buffer_head *fe_bh,
  96                                     struct buffer_head *bg_bh,
  97                                     struct buffer_head *prev_bg_bh,
  98                                     u16 chain);
  99 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
 100                                                      u32 wanted);
 101 static int ocfs2_free_suballoc_bits(handle_t *handle,
 102                                     struct inode *alloc_inode,
 103                                     struct buffer_head *alloc_bh,
 104                                     unsigned int start_bit,
 105                                     u64 bg_blkno,
 106                                     unsigned int count);
 107 static inline u64 ocfs2_which_suballoc_group(u64 block,
 108                                              unsigned int bit);
 109 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
 110                                                    u64 bg_blkno,
 111                                                    u16 bg_bit_off);
 112 static inline u64 ocfs2_which_cluster_group(struct inode *inode,
 113                                             u32 cluster);
 114 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
 115                                                 u64 data_blkno,
 116                                                 u64 *bg_blkno,
 117                                                 u16 *bg_bit_off);
 118
 119 void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
 120 {
 121         struct inode *inode = ac->ac_inode;
 122
 123         if (inode) {
 124                 if (ac->ac_which != OCFS2_AC_USE_LOCAL)
 125                         ocfs2_meta_unlock(inode, 1);
 126
 127                 mutex_unlock(&inode->i_mutex);
 128
 129                 iput(inode);
 130         }
 131         if (ac->ac_bh)
 132                 brelse(ac->ac_bh);
 133         kfree(ac);
 134 }
 135
 136 static u32 ocfs2_bits_per_group(struct ocfs2_chain_list *cl)
 137 {
 138         return (u32)le16_to_cpu(cl->cl_cpg) * (u32)le16_to_cpu(cl->cl_bpc);
 139 }
 140
 141 /* somewhat more expensive than our other checks, so use sparingly. */
 142 static int ocfs2_check_group_descriptor(struct super_block *sb,
 143                                         struct ocfs2_dinode *di,
 144                                         struct ocfs2_group_desc *gd)
 145 {
 146         unsigned int max_bits;
 147
 148         if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
 149                 OCFS2_RO_ON_INVALID_GROUP_DESC(sb, gd);
 150                 return -EIO;
 151         }
 152
 153         if (di->i_blkno != gd->bg_parent_dinode) {
 154                 ocfs2_error(sb, "Group descriptor # %llu has bad parent "
 155                             "pointer (%llu, expected %llu)",
 156                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 157                             (unsigned long long)le64_to_cpu(gd->bg_parent_dinode),
 158                             (unsigned long long)le64_to_cpu(di->i_blkno));
 159                 return -EIO;
 160         }
 161
 162         max_bits = le16_to_cpu(di->id2.i_chain.cl_cpg) * le16_to_cpu(di->id2.i_chain.cl_bpc);
 163         if (le16_to_cpu(gd->bg_bits) > max_bits) {
 164                 ocfs2_error(sb, "Group descriptor # %llu has bit count of %u",
 165                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 166                             le16_to_cpu(gd->bg_bits));
 167                 return -EIO;
 168         }
 169
 170         if (le16_to_cpu(gd->bg_chain) >=
 171             le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) {
 172                 ocfs2_error(sb, "Group descriptor # %llu has bad chain %u",
 173                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 174                             le16_to_cpu(gd->bg_chain));
 175                 return -EIO;
 176         }
 177
 178         if (le16_to_cpu(gd->bg_free_bits_count) > le16_to_cpu(gd->bg_bits)) {
 179                 ocfs2_error(sb, "Group descriptor # %llu has bit count %u but "
 180                             "claims that %u are free",
 181                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 182                             le16_to_cpu(gd->bg_bits),
 183                             le16_to_cpu(gd->bg_free_bits_count));
 184                 return -EIO;
 185         }
 186
 187         if (le16_to_cpu(gd->bg_bits) > (8 * le16_to_cpu(gd->bg_size))) {
 188                 ocfs2_error(sb, "Group descriptor # %llu has bit count %u but "
 189                             "max bitmap bits of %u",
 190                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 191                             le16_to_cpu(gd->bg_bits),
 192                             8 * le16_to_cpu(gd->bg_size));
 193                 return -EIO;
 194         }
 195
 196         return 0;
 197 }
 198
 199 static int ocfs2_block_group_fill(handle_t *handle,
 200                                   struct inode *alloc_inode,
 201                                   struct buffer_head *bg_bh,
 202                                   u64 group_blkno,
 203                                   u16 my_chain,
 204                                   struct ocfs2_chain_list *cl)
 205 {
 206         int status = 0;
 207         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 208         struct super_block * sb = alloc_inode->i_sb;
 209
 210         mlog_entry_void();
 211
 212         if (((unsigned long long) bg_bh->b_blocknr) != group_blkno) {
 213                 ocfs2_error(alloc_inode->i_sb, "group block (%llu) != "
 214                             "b_blocknr (%llu)",
 215                             (unsigned long long)group_blkno,
 216                             (unsigned long long) bg_bh->b_blocknr);
 217                 status = -EIO;
 218                 goto bail;
 219         }
 220
 221         status = ocfs2_journal_access(handle,
 222                                       alloc_inode,
 223                                       bg_bh,
 224                                       OCFS2_JOURNAL_ACCESS_CREATE);
 225         if (status < 0) {
 226                 mlog_errno(status);
 227                 goto bail;
 228         }
 229
 230         memset(bg, 0, sb->s_blocksize);
 231         strcpy(bg->bg_signature, OCFS2_GROUP_DESC_SIGNATURE);
 232         bg->bg_generation = cpu_to_le32(OCFS2_SB(sb)->fs_generation);
 233         bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb));
 234         bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
 235         bg->bg_chain = cpu_to_le16(my_chain);
 236         bg->bg_next_group = cl->cl_recs[my_chain].c_blkno;
 237         bg->bg_parent_dinode = cpu_to_le64(OCFS2_I(alloc_inode)->ip_blkno);
 238         bg->bg_blkno = cpu_to_le64(group_blkno);
 239         /* set the 1st bit in the bitmap to account for the descriptor block */
 240         ocfs2_set_bit(0, (unsigned long *)bg->bg_bitmap);
 241         bg->bg_free_bits_count = cpu_to_le16(le16_to_cpu(bg->bg_bits) - 1);
 242
 243         status = ocfs2_journal_dirty(handle, bg_bh);
 244         if (status < 0)
 245                 mlog_errno(status);
 246
 247         /* There is no need to zero out or otherwise initialize the
 248          * other blocks in a group - All valid FS metadata in a block
 249          * group stores the superblock fs_generation value at
 250          * allocation time. */
 251
 252 bail:
 253         mlog_exit(status);
 254         return status;
 255 }
 256
 257 static inline u16 ocfs2_find_smallest_chain(struct ocfs2_chain_list *cl)
 258 {
 259         u16 curr, best;
 260
 261         best = curr = 0;
 262         while (curr < le16_to_cpu(cl->cl_count)) {
 263                 if (le32_to_cpu(cl->cl_recs[best].c_total) >
 264                     le32_to_cpu(cl->cl_recs[curr].c_total))
 265                         best = curr;
 266                 curr++;
 267         }
 268         return best;
 269 }
 270
 271 /*
 272  * We expect the block group allocator to already be locked.
 273  */
 274 static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
 275                                    struct inode *alloc_inode,
 276                                    struct buffer_head *bh)
 277 {
 278         int status, credits;
 279         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) bh->b_data;
 280         struct ocfs2_chain_list *cl;
 281         struct ocfs2_alloc_context *ac = NULL;
 282         handle_t *handle = NULL;
 283         u32 bit_off, num_bits;
 284         u16 alloc_rec;
 285         u64 bg_blkno;
 286         struct buffer_head *bg_bh = NULL;
 287         struct ocfs2_group_desc *bg;
 288
 289         BUG_ON(ocfs2_is_cluster_bitmap(alloc_inode));
 290
 291         mlog_entry_void();
 292
 293         cl = &fe->id2.i_chain;
 294         status = ocfs2_reserve_clusters(osb,
 295                                         le16_to_cpu(cl->cl_cpg),
 296                                         &ac);
 297         if (status < 0) {
 298                 if (status != -ENOSPC)
 299                         mlog_errno(status);
 300                 goto bail;
 301         }
 302
 303         credits = ocfs2_calc_group_alloc_credits(osb->sb,
 304                                                  le16_to_cpu(cl->cl_cpg));
 305         handle = ocfs2_start_trans(osb, credits);
 306         if (IS_ERR(handle)) {
 307                 status = PTR_ERR(handle);
 308                 handle = NULL;
 309                 mlog_errno(status);
 310                 goto bail;
 311         }
 312
 313         status = ocfs2_claim_clusters(osb,
 314                                       handle,
 315                                       ac,
 316                                       le16_to_cpu(cl->cl_cpg),
 317                                       &bit_off,
 318                                       &num_bits);
 319         if (status < 0) {
 320                 if (status != -ENOSPC)
 321                         mlog_errno(status);
 322                 goto bail;
 323         }
 324
 325         alloc_rec = ocfs2_find_smallest_chain(cl);
 326
 327         /* setup the group */
 328         bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 329         mlog(0, "new descriptor, record %u, at block %llu\n",
 330              alloc_rec, (unsigned long long)bg_blkno);
 331
 332         bg_bh = sb_getblk(osb->sb, bg_blkno);
 333         if (!bg_bh) {
 334                 status = -EIO;
 335                 mlog_errno(status);
 336                 goto bail;
 337         }
 338         ocfs2_set_new_buffer_uptodate(alloc_inode, bg_bh);
 339
 340         status = ocfs2_block_group_fill(handle,
 341                                         alloc_inode,
 342                                         bg_bh,
 343                                         bg_blkno,
 344                                         alloc_rec,
 345                                         cl);
 346         if (status < 0) {
 347                 mlog_errno(status);
 348                 goto bail;
 349         }
 350
 351         bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 352
 353         status = ocfs2_journal_access(handle, alloc_inode,
 354                                       bh, OCFS2_JOURNAL_ACCESS_WRITE);
 355         if (status < 0) {
 356                 mlog_errno(status);
 357                 goto bail;
 358         }
 359
 360         le32_add_cpu(&cl->cl_recs[alloc_rec].c_free,
 361                      le16_to_cpu(bg->bg_free_bits_count));
 362         le32_add_cpu(&cl->cl_recs[alloc_rec].c_total, le16_to_cpu(bg->bg_bits));
 363         cl->cl_recs[alloc_rec].c_blkno  = cpu_to_le64(bg_blkno);
 364         if (le16_to_cpu(cl->cl_next_free_rec) < le16_to_cpu(cl->cl_count))
 365                 le16_add_cpu(&cl->cl_next_free_rec, 1);
 366
 367         le32_add_cpu(&fe->id1.bitmap1.i_used, le16_to_cpu(bg->bg_bits) -
 368                                         le16_to_cpu(bg->bg_free_bits_count));
 369         le32_add_cpu(&fe->id1.bitmap1.i_total, le16_to_cpu(bg->bg_bits));
 370         le32_add_cpu(&fe->i_clusters, le16_to_cpu(cl->cl_cpg));
 371
 372         status = ocfs2_journal_dirty(handle, bh);
 373         if (status < 0) {
 374                 mlog_errno(status);
 375                 goto bail;
 376         }
 377
 378         spin_lock(&OCFS2_I(alloc_inode)->ip_lock);
 379         OCFS2_I(alloc_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
 380         fe->i_size = cpu_to_le64(ocfs2_clusters_to_bytes(alloc_inode->i_sb,
 381                                              le32_to_cpu(fe->i_clusters)));
 382         spin_unlock(&OCFS2_I(alloc_inode)->ip_lock);
 383         i_size_write(alloc_inode, le64_to_cpu(fe->i_size));
 384         alloc_inode->i_blocks = ocfs2_inode_sector_count(alloc_inode);
 385
 386         status = 0;
 387 bail:
 388         if (handle)
 389                 ocfs2_commit_trans(osb, handle);
 390
 391         if (ac)
 392                 ocfs2_free_alloc_context(ac);
 393
 394         if (bg_bh)
 395                 brelse(bg_bh);
 396
 397         mlog_exit(status);
 398         return status;
 399 }
 400
 401 static int ocfs2_reserve_suballoc_bits(struct ocfs2_super *osb,
 402                                        struct ocfs2_alloc_context *ac,
 403                                        int type,
 404                                        u32 slot)
 405 {
 406         int status;
 407         u32 bits_wanted = ac->ac_bits_wanted;
 408         struct inode *alloc_inode;
 409         struct buffer_head *bh = NULL;
 410         struct ocfs2_dinode *fe;
 411         u32 free_bits;
 412
 413         mlog_entry_void();
 414
 415         alloc_inode = ocfs2_get_system_file_inode(osb, type, slot);
 416         if (!alloc_inode) {
 417                 mlog_errno(-EINVAL);
 418                 return -EINVAL;
 419         }
 420
 421         mutex_lock(&alloc_inode->i_mutex);
 422
 423         status = ocfs2_meta_lock(alloc_inode, &bh, 1);
 424         if (status < 0) {
 425                 mutex_unlock(&alloc_inode->i_mutex);
 426                 iput(alloc_inode);
 427
 428                 mlog_errno(status);
 429                 return status;
 430         }
 431
 432         ac->ac_inode = alloc_inode;
 433
 434         fe = (struct ocfs2_dinode *) bh->b_data;
 435         if (!OCFS2_IS_VALID_DINODE(fe)) {
 436                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
 437                 status = -EIO;
 438                 goto bail;
 439         }
 440         if (!(fe->i_flags & cpu_to_le32(OCFS2_CHAIN_FL))) {
 441                 ocfs2_error(alloc_inode->i_sb, "Invalid chain allocator %llu",
 442                             (unsigned long long)le64_to_cpu(fe->i_blkno));
 443                 status = -EIO;
 444                 goto bail;
 445         }
 446
 447         free_bits = le32_to_cpu(fe->id1.bitmap1.i_total) -
 448                 le32_to_cpu(fe->id1.bitmap1.i_used);
 449
 450         if (bits_wanted > free_bits) {
 451                 /* cluster bitmap never grows */
 452                 if (ocfs2_is_cluster_bitmap(alloc_inode)) {
 453                         mlog(0, "Disk Full: wanted=%u, free_bits=%u\n",
 454                              bits_wanted, free_bits);
 455                         status = -ENOSPC;
 456                         goto bail;
 457                 }
 458
 459                 status = ocfs2_block_group_alloc(osb, alloc_inode, bh);
 460                 if (status < 0) {
 461                         if (status != -ENOSPC)
 462                                 mlog_errno(status);
 463                         goto bail;
 464                 }
 465                 atomic_inc(&osb->alloc_stats.bg_extends);
 466
 467                 /* You should never ask for this much metadata */
 468                 BUG_ON(bits_wanted >
 469                        (le32_to_cpu(fe->id1.bitmap1.i_total)
 470                         - le32_to_cpu(fe->id1.bitmap1.i_used)));
 471         }
 472
 473         get_bh(bh);
 474         ac->ac_bh = bh;
 475 bail:
 476         if (bh)
 477                 brelse(bh);
 478
 479         mlog_exit(status);
 480         return status;
 481 }
 482
 483 int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
 484                                struct ocfs2_dinode *fe,
 485                                struct ocfs2_alloc_context **ac)
 486 {
 487         int status;
 488         u32 slot;
 489
 490         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 491         if (!(*ac)) {
 492                 status = -ENOMEM;
 493                 mlog_errno(status);
 494                 goto bail;
 495         }
 496
 497         (*ac)->ac_bits_wanted = ocfs2_extend_meta_needed(fe);
 498         (*ac)->ac_which = OCFS2_AC_USE_META;
 499
 500 #ifndef OCFS2_USE_ALL_METADATA_SUBALLOCATORS
 501         slot = 0;
 502 #else
 503         slot = osb->slot_num;
 504 #endif
 505
 506         (*ac)->ac_group_search = ocfs2_block_group_search;
 507
 508         status = ocfs2_reserve_suballoc_bits(osb, (*ac),
 509                                              EXTENT_ALLOC_SYSTEM_INODE, slot);
 510         if (status < 0) {
 511                 if (status != -ENOSPC)
 512                         mlog_errno(status);
 513                 goto bail;
 514         }
 515
 516         status = 0;
 517 bail:
 518         if ((status < 0) && *ac) {
 519                 ocfs2_free_alloc_context(*ac);
 520                 *ac = NULL;
 521         }
 522
 523         mlog_exit(status);
 524         return status;
 525 }
 526
 527 int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
 528                             struct ocfs2_alloc_context **ac)
 529 {
 530         int status;
 531
 532         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 533         if (!(*ac)) {
 534                 status = -ENOMEM;
 535                 mlog_errno(status);
 536                 goto bail;
 537         }
 538
 539         (*ac)->ac_bits_wanted = 1;
 540         (*ac)->ac_which = OCFS2_AC_USE_INODE;
 541
 542         (*ac)->ac_group_search = ocfs2_block_group_search;
 543
 544         status = ocfs2_reserve_suballoc_bits(osb, *ac,
 545                                              INODE_ALLOC_SYSTEM_INODE,
 546                                              osb->slot_num);
 547         if (status < 0) {
 548                 if (status != -ENOSPC)
 549                         mlog_errno(status);
 550                 goto bail;
 551         }
 552
 553         status = 0;
 554 bail:
 555         if ((status < 0) && *ac) {
 556                 ocfs2_free_alloc_context(*ac);
 557                 *ac = NULL;
 558         }
 559
 560         mlog_exit(status);
 561         return status;
 562 }
 563
 564 /* local alloc code has to do the same thing, so rather than do this
 565  * twice.. */
 566 int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
 567                                       struct ocfs2_alloc_context *ac)
 568 {
 569         int status;
 570
 571         ac->ac_which = OCFS2_AC_USE_MAIN;
 572         ac->ac_group_search = ocfs2_cluster_group_search;
 573
 574         status = ocfs2_reserve_suballoc_bits(osb, ac,
 575                                              GLOBAL_BITMAP_SYSTEM_INODE,
 576                                              OCFS2_INVALID_SLOT);
 577         if (status < 0 && status != -ENOSPC) {
 578                 mlog_errno(status);
 579                 goto bail;
 580         }
 581
 582 bail:
 583         return status;
 584 }
 585
 586 /* Callers don't need to care which bitmap (local alloc or main) to
 587  * use so we figure it out for them, but unfortunately this clutters
 588  * things a bit. */
 589 int ocfs2_reserve_clusters(struct ocfs2_super *osb,
 590                            u32 bits_wanted,
 591                            struct ocfs2_alloc_context **ac)
 592 {
 593         int status;
 594
 595         mlog_entry_void();
 596
 597         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 598         if (!(*ac)) {
 599                 status = -ENOMEM;
 600                 mlog_errno(status);
 601                 goto bail;
 602         }
 603
 604         (*ac)->ac_bits_wanted = bits_wanted;
 605
 606         status = -ENOSPC;
 607         if (ocfs2_alloc_should_use_local(osb, bits_wanted)) {
 608                 status = ocfs2_reserve_local_alloc_bits(osb,
 609                                                         bits_wanted,
 610                                                         *ac);
 611                 if ((status < 0) && (status != -ENOSPC)) {
 612                         mlog_errno(status);
 613                         goto bail;
 614                 } else if (status == -ENOSPC) {
 615                         /* reserve_local_bits will return enospc with
 616                          * the local alloc inode still locked, so we
 617                          * can change this safely here. */
 618                         mlog(0, "Disabling local alloc\n");
 619                         /* We set to OCFS2_LA_DISABLED so that umount
 620                          * can clean up what's left of the local
 621                          * allocation */
 622                         osb->local_alloc_state = OCFS2_LA_DISABLED;
 623                 }
 624         }
 625
 626         if (status == -ENOSPC) {
 627                 status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
 628                 if (status < 0) {
 629                         if (status != -ENOSPC)
 630                                 mlog_errno(status);
 631                         goto bail;
 632                 }
 633         }
 634
 635         status = 0;
 636 bail:
 637         if ((status < 0) && *ac) {
 638                 ocfs2_free_alloc_context(*ac);
 639                 *ac = NULL;
 640         }
 641
 642         mlog_exit(status);
 643         return status;
 644 }
 645
 646 /*
 647  * More or less lifted from ext3. I'll leave their description below:
 648  *
 649  * "For ext3 allocations, we must not reuse any blocks which are
 650  * allocated in the bitmap buffer's "last committed data" copy.  This
 651  * prevents deletes from freeing up the page for reuse until we have
 652  * committed the delete transaction.
 653  *
 654  * If we didn't do this, then deleting something and reallocating it as
 655  * data would allow the old block to be overwritten before the
 656  * transaction committed (because we force data to disk before commit).
 657  * This would lead to corruption if we crashed between overwriting the
 658  * data and committing the delete.
 659  *
 660  * @@@ We may want to make this allocation behaviour conditional on
 661  * data-writes at some point, and disable it for metadata allocations or
 662  * sync-data inodes."
 663  *
 664  * Note: OCFS2 already does this differently for metadata vs data
 665  * allocations, as those bitmaps are seperate and undo access is never
 666  * called on a metadata group descriptor.
 667  */
 668 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
 669                                          int nr)
 670 {
 671         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 672
 673         if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
 674                 return 0;
 675         if (!buffer_jbd(bg_bh) || !bh2jh(bg_bh)->b_committed_data)
 676                 return 1;
 677
 678         bg = (struct ocfs2_group_desc *) bh2jh(bg_bh)->b_committed_data;
 679         return !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
 680 }
 681
 682 static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
 683                                              struct buffer_head *bg_bh,
 684                                              unsigned int bits_wanted,
 685                                              unsigned int total_bits,
 686                                              u16 *bit_off,
 687                                              u16 *bits_found)
 688 {
 689         void *bitmap;
 690         u16 best_offset, best_size;
 691         int offset, start, found, status = 0;
 692         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 693
 694         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
 695                 OCFS2_RO_ON_INVALID_GROUP_DESC(osb->sb, bg);
 696                 return -EIO;
 697         }
 698
 699         found = start = best_offset = best_size = 0;
 700         bitmap = bg->bg_bitmap;
 701
 702         while((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) != -1) {
 703                 if (offset == total_bits)
 704                         break;
 705
 706                 if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
 707                         /* We found a zero, but we can't use it as it
 708                          * hasn't been put to disk yet! */
 709                         found = 0;
 710                         start = offset + 1;
 711                 } else if (offset == start) {
 712                         /* we found a zero */
 713                         found++;
 714                         /* move start to the next bit to test */
 715                         start++;
 716                 } else {
 717                         /* got a zero after some ones */
 718                         found = 1;
 719                         start = offset + 1;
 720                 }
 721                 if (found > best_size) {
 722                         best_size = found;
 723                         best_offset = start - found;
 724                 }
 725                 /* we got everything we needed */
 726                 if (found == bits_wanted) {
 727                         /* mlog(0, "Found it all!\n"); */
 728                         break;
 729                 }
 730         }
 731
 732         /* XXX: I think the first clause is equivalent to the second
 733          *      - jlbec */
 734         if (found == bits_wanted) {
 735                 *bit_off = start - found;
 736                 *bits_found = found;
 737         } else if (best_size) {
 738                 *bit_off = best_offset;
 739                 *bits_found = best_size;
 740         } else {
 741                 status = -ENOSPC;
 742                 /* No error log here -- see the comment above
 743                  * ocfs2_test_bg_bit_allocatable */
 744         }
 745
 746         return status;
 747 }
 748
 749 static inline int ocfs2_block_group_set_bits(handle_t *handle,
 750                                              struct inode *alloc_inode,
 751                                              struct ocfs2_group_desc *bg,
 752                                              struct buffer_head *group_bh,
 753                                              unsigned int bit_off,
 754                                              unsigned int num_bits)
 755 {
 756         int status;
 757         void *bitmap = bg->bg_bitmap;
 758         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
 759
 760         mlog_entry_void();
 761
 762         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
 763                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
 764                 status = -EIO;
 765                 goto bail;
 766         }
 767         BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
 768
 769         mlog(0, "block_group_set_bits: off = %u, num = %u\n", bit_off,
 770              num_bits);
 771
 772         if (ocfs2_is_cluster_bitmap(alloc_inode))
 773                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
 774
 775         status = ocfs2_journal_access(handle,
 776                                       alloc_inode,
 777                                       group_bh,
 778                                       journal_type);
 779         if (status < 0) {
 780                 mlog_errno(status);
 781                 goto bail;
 782         }
 783
 784         le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
 785
 786         while(num_bits--)
 787                 ocfs2_set_bit(bit_off++, bitmap);
 788
 789         status = ocfs2_journal_dirty(handle,
 790                                      group_bh);
 791         if (status < 0) {
 792                 mlog_errno(status);
 793                 goto bail;
 794         }
 795
 796 bail:
 797         mlog_exit(status);
 798         return status;
 799 }
 800
 801 /* find the one with the most empty bits */
 802 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
 803 {
 804         u16 curr, best;
 805
 806         BUG_ON(!cl->cl_next_free_rec);
 807
 808         best = curr = 0;
 809         while (curr < le16_to_cpu(cl->cl_next_free_rec)) {
 810                 if (le32_to_cpu(cl->cl_recs[curr].c_free) >
 811                     le32_to_cpu(cl->cl_recs[best].c_free))
 812                         best = curr;
 813                 curr++;
 814         }
 815
 816         BUG_ON(best >= le16_to_cpu(cl->cl_next_free_rec));
 817         return best;
 818 }
 819
 820 static int ocfs2_relink_block_group(handle_t *handle,
 821                                     struct inode *alloc_inode,
 822                                     struct buffer_head *fe_bh,
 823                                     struct buffer_head *bg_bh,
 824                                     struct buffer_head *prev_bg_bh,
 825                                     u16 chain)
 826 {
 827         int status;
 828         /* there is a really tiny chance the journal calls could fail,
 829          * but we wouldn't want inconsistent blocks in *any* case. */
 830         u64 fe_ptr, bg_ptr, prev_bg_ptr;
 831         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
 832         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 833         struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
 834
 835         if (!OCFS2_IS_VALID_DINODE(fe)) {
 836                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
 837                 status = -EIO;
 838                 goto out;
 839         }
 840         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
 841                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
 842                 status = -EIO;
 843                 goto out;
 844         }
 845         if (!OCFS2_IS_VALID_GROUP_DESC(prev_bg)) {
 846                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, prev_bg);
 847                 status = -EIO;
 848                 goto out;
 849         }
 850
 851         mlog(0, "Suballoc %llu, chain %u, move group %llu to top, prev = %llu\n",
 852              (unsigned long long)le64_to_cpu(fe->i_blkno), chain,
 853              (unsigned long long)le64_to_cpu(bg->bg_blkno),
 854              (unsigned long long)le64_to_cpu(prev_bg->bg_blkno));
 855
 856         fe_ptr = le64_to_cpu(fe->id2.i_chain.cl_recs[chain].c_blkno);
 857         bg_ptr = le64_to_cpu(bg->bg_next_group);
 858         prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
 859
 860         status = ocfs2_journal_access(handle, alloc_inode, prev_bg_bh,
 861                                       OCFS2_JOURNAL_ACCESS_WRITE);
 862         if (status < 0) {
 863                 mlog_errno(status);
 864                 goto out_rollback;
 865         }
 866
 867         prev_bg->bg_next_group = bg->bg_next_group;
 868
 869         status = ocfs2_journal_dirty(handle, prev_bg_bh);
 870         if (status < 0) {
 871                 mlog_errno(status);
 872                 goto out_rollback;
 873         }
 874
 875         status = ocfs2_journal_access(handle, alloc_inode, bg_bh,
 876                                       OCFS2_JOURNAL_ACCESS_WRITE);
 877         if (status < 0) {
 878                 mlog_errno(status);
 879                 goto out_rollback;
 880         }
 881
 882         bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
 883
 884         status = ocfs2_journal_dirty(handle, bg_bh);
 885         if (status < 0) {
 886                 mlog_errno(status);
 887                 goto out_rollback;
 888         }
 889
 890         status = ocfs2_journal_access(handle, alloc_inode, fe_bh,
 891                                       OCFS2_JOURNAL_ACCESS_WRITE);
 892         if (status < 0) {
 893                 mlog_errno(status);
 894                 goto out_rollback;
 895         }
 896
 897         fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
 898
 899         status = ocfs2_journal_dirty(handle, fe_bh);
 900         if (status < 0) {
 901                 mlog_errno(status);
 902                 goto out_rollback;
 903         }
 904
 905         status = 0;
 906 out_rollback:
 907         if (status < 0) {
 908                 fe->id2.i_chain.cl_recs[chain].c_blkno = cpu_to_le64(fe_ptr);
 909                 bg->bg_next_group = cpu_to_le64(bg_ptr);
 910                 prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
 911         }
 912 out:
 913         mlog_exit(status);
 914         return status;
 915 }
 916
 917 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
 918                                                      u32 wanted)
 919 {
 920         return le16_to_cpu(bg->bg_free_bits_count) > wanted;
 921 }
 922
 923 /* return 0 on success, -ENOSPC to keep searching and any other < 0
 924  * value on error. */
 925 static int ocfs2_cluster_group_search(struct inode *inode,
 926                                       struct buffer_head *group_bh,
 927                                       u32 bits_wanted, u32 min_bits,
 928                                       u16 *bit_off, u16 *bits_found)
 929 {
 930         int search = -ENOSPC;
 931         int ret;
 932         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
 933         u16 tmp_off, tmp_found;
 934         unsigned int max_bits, gd_cluster_off;
 935
 936         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
 937
 938         if (gd->bg_free_bits_count) {
 939                 max_bits = le16_to_cpu(gd->bg_bits);
 940
 941                 /* Tail groups in cluster bitmaps which aren't cpg
 942                  * aligned are prone to partial extention by a failed
 943                  * fs resize. If the file system resize never got to
 944                  * update the dinode cluster count, then we don't want
 945                  * to trust any clusters past it, regardless of what
 946                  * the group descriptor says. */
 947                 gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
 948                                                           le64_to_cpu(gd->bg_blkno));
 949                 if ((gd_cluster_off + max_bits) >
 950                     OCFS2_I(inode)->ip_clusters) {
 951                         max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
 952                         mlog(0, "Desc %llu, bg_bits %u, clusters %u, use %u\n",
 953                              (unsigned long long)le64_to_cpu(gd->bg_blkno),
 954                              le16_to_cpu(gd->bg_bits),
 955                              OCFS2_I(inode)->ip_clusters, max_bits);
 956                 }
 957
 958                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
 959                                                         group_bh, bits_wanted,
 960                                                         max_bits,
 961                                                         &tmp_off, &tmp_found);
 962                 if (ret)
 963                         return ret;
 964
 965                 /* ocfs2_block_group_find_clear_bits() might
 966                  * return success, but we still want to return
 967                  * -ENOSPC unless it found the minimum number
 968                  * of bits. */
 969                 if (min_bits <= tmp_found) {
 970                         *bit_off = tmp_off;
 971                         *bits_found = tmp_found;
 972                         search = 0; /* success */
 973                 }
 974         }
 975
 976         return search;
 977 }
 978
 979 static int ocfs2_block_group_search(struct inode *inode,
 980                                     struct buffer_head *group_bh,
 981                                     u32 bits_wanted, u32 min_bits,
 982                                     u16 *bit_off, u16 *bits_found)
 983 {
 984         int ret = -ENOSPC;
 985         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
 986
 987         BUG_ON(min_bits != 1);
 988         BUG_ON(ocfs2_is_cluster_bitmap(inode));
 989
 990         if (bg->bg_free_bits_count)
 991                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
 992                                                         group_bh, bits_wanted,
 993                                                         le16_to_cpu(bg->bg_bits),
 994                                                         bit_off, bits_found);
 995
 996         return ret;
 997 }
 998
 999 static int ocfs2_alloc_dinode_update_counts(struct inode *inode,
1000                                        handle_t *handle,
1001                                        struct buffer_head *di_bh,
1002                                        u32 num_bits,
1003                                        u16 chain)
1004 {
1005         int ret;
1006         u32 tmp_used;
1007         struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1008         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &di->id2.i_chain;
1009
1010         ret = ocfs2_journal_access(handle, inode, di_bh,
1011                                    OCFS2_JOURNAL_ACCESS_WRITE);
1012         if (ret < 0) {
1013                 mlog_errno(ret);
1014                 goto out;
1015         }
1016
1017         tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1018         di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
1019         le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
1020
1021         ret = ocfs2_journal_dirty(handle, di_bh);
1022         if (ret < 0)
1023                 mlog_errno(ret);
1024
1025 out:
1026         return ret;
1027 }
1028
1029 static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
1030                                   handle_t *handle,
1031                                   u32 bits_wanted,
1032                                   u32 min_bits,
1033                                   u16 *bit_off,
1034                                   unsigned int *num_bits,
1035                                   u64 gd_blkno,
1036                                   u16 *bits_left)
1037 {
1038         int ret;
1039         u16 found;
1040         struct buffer_head *group_bh = NULL;
1041         struct ocfs2_group_desc *gd;
1042         struct inode *alloc_inode = ac->ac_inode;
1043
1044         ret = ocfs2_read_block(OCFS2_SB(alloc_inode->i_sb), gd_blkno,
1045                                &group_bh, OCFS2_BH_CACHED, alloc_inode);
1046         if (ret < 0) {
1047                 mlog_errno(ret);
1048                 return ret;
1049         }
1050
1051         gd = (struct ocfs2_group_desc *) group_bh->b_data;
1052         if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
1053                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, gd);
1054                 ret = -EIO;
1055                 goto out;
1056         }
1057
1058         ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
1059                                   bit_off, &found);
1060         if (ret < 0) {
1061                 if (ret != -ENOSPC)
1062                         mlog_errno(ret);
1063                 goto out;
1064         }
1065
1066         *num_bits = found;
1067
1068         ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
1069                                                *num_bits,
1070                                                le16_to_cpu(gd->bg_chain));
1071         if (ret < 0) {
1072                 mlog_errno(ret);
1073                 goto out;
1074         }
1075
1076         ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
1077                                          *bit_off, *num_bits);
1078         if (ret < 0)
1079                 mlog_errno(ret);
1080
1081         *bits_left = le16_to_cpu(gd->bg_free_bits_count);
1082
1083 out:
1084         brelse(group_bh);
1085
1086         return ret;
1087 }
1088
1089 static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
1090                               handle_t *handle,
1091                               u32 bits_wanted,
1092                               u32 min_bits,
1093                               u16 *bit_off,
1094                               unsigned int *num_bits,
1095                               u64 *bg_blkno,
1096                               u16 *bits_left)
1097 {
1098         int status;
1099         u16 chain, tmp_bits;
1100         u32 tmp_used;
1101         u64 next_group;
1102         struct inode *alloc_inode = ac->ac_inode;
1103         struct buffer_head *group_bh = NULL;
1104         struct buffer_head *prev_group_bh = NULL;
1105         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1106         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1107         struct ocfs2_group_desc *bg;
1108
1109         chain = ac->ac_chain;
1110         mlog(0, "trying to alloc %u bits from chain %u, inode %llu\n",
1111              bits_wanted, chain,
1112              (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno);
1113
1114         status = ocfs2_read_block(OCFS2_SB(alloc_inode->i_sb),
1115                                   le64_to_cpu(cl->cl_recs[chain].c_blkno),
1116                                   &group_bh, OCFS2_BH_CACHED, alloc_inode);
1117         if (status < 0) {
1118                 mlog_errno(status);
1119                 goto bail;
1120         }
1121         bg = (struct ocfs2_group_desc *) group_bh->b_data;
1122         status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, bg);
1123         if (status) {
1124                 mlog_errno(status);
1125                 goto bail;
1126         }
1127
1128         status = -ENOSPC;
1129         /* for now, the chain search is a bit simplistic. We just use
1130          * the 1st group with any empty bits. */
1131         while ((status = ac->ac_group_search(alloc_inode, group_bh,
1132                                              bits_wanted, min_bits, bit_off,
1133                                              &tmp_bits)) == -ENOSPC) {
1134                 if (!bg->bg_next_group)
1135                         break;
1136
1137                 if (prev_group_bh) {
1138                         brelse(prev_group_bh);
1139                         prev_group_bh = NULL;
1140                 }
1141                 next_group = le64_to_cpu(bg->bg_next_group);
1142                 prev_group_bh = group_bh;
1143                 group_bh = NULL;
1144                 status = ocfs2_read_block(OCFS2_SB(alloc_inode->i_sb),
1145                                           next_group, &group_bh,
1146                                           OCFS2_BH_CACHED, alloc_inode);
1147                 if (status < 0) {
1148                         mlog_errno(status);
1149                         goto bail;
1150                 }
1151                 bg = (struct ocfs2_group_desc *) group_bh->b_data;
1152                 status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, bg);
1153                 if (status) {
1154                         mlog_errno(status);
1155                         goto bail;
1156                 }
1157         }
1158         if (status < 0) {
1159                 if (status != -ENOSPC)
1160                         mlog_errno(status);
1161                 goto bail;
1162         }
1163
1164         mlog(0, "alloc succeeds: we give %u bits from block group %llu\n",
1165              tmp_bits, (unsigned long long)le64_to_cpu(bg->bg_blkno));
1166
1167         *num_bits = tmp_bits;
1168
1169         BUG_ON(*num_bits == 0);
1170
1171         /*
1172          * Keep track of previous block descriptor read. When
1173          * we find a target, if we have read more than X
1174          * number of descriptors, and the target is reasonably
1175          * empty, relink him to top of his chain.
1176          *
1177          * We've read 0 extra blocks and only send one more to
1178          * the transaction, yet the next guy to search has a
1179          * much easier time.
1180          *
1181          * Do this *after* figuring out how many bits we're taking out
1182          * of our target group.
1183          */
1184         if (ac->ac_allow_chain_relink &&
1185             (prev_group_bh) &&
1186             (ocfs2_block_group_reasonably_empty(bg, *num_bits))) {
1187                 status = ocfs2_relink_block_group(handle, alloc_inode,
1188                                                   ac->ac_bh, group_bh,
1189                                                   prev_group_bh, chain);
1190                 if (status < 0) {
1191                         mlog_errno(status);
1192                         goto bail;
1193                 }
1194         }
1195
1196         /* Ok, claim our bits now: set the info on dinode, chainlist
1197          * and then the group */
1198         status = ocfs2_journal_access(handle,
1199                                       alloc_inode,
1200                                       ac->ac_bh,
1201                                       OCFS2_JOURNAL_ACCESS_WRITE);
1202         if (status < 0) {
1203                 mlog_errno(status);
1204                 goto bail;
1205         }
1206
1207         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
1208         fe->id1.bitmap1.i_used = cpu_to_le32(*num_bits + tmp_used);
1209         le32_add_cpu(&cl->cl_recs[chain].c_free, -(*num_bits));
1210
1211         status = ocfs2_journal_dirty(handle,
1212                                      ac->ac_bh);
1213         if (status < 0) {
1214                 mlog_errno(status);
1215                 goto bail;
1216         }
1217
1218         status = ocfs2_block_group_set_bits(handle,
1219                                             alloc_inode,
1220                                             bg,
1221                                             group_bh,
1222                                             *bit_off,
1223                                             *num_bits);
1224         if (status < 0) {
1225                 mlog_errno(status);
1226                 goto bail;
1227         }
1228
1229         mlog(0, "Allocated %u bits from suballocator %llu\n", *num_bits,
1230              (unsigned long long)le64_to_cpu(fe->i_blkno));
1231
1232         *bg_blkno = le64_to_cpu(bg->bg_blkno);
1233         *bits_left = le16_to_cpu(bg->bg_free_bits_count);
1234 bail:
1235         if (group_bh)
1236                 brelse(group_bh);
1237         if (prev_group_bh)
1238                 brelse(prev_group_bh);
1239
1240         mlog_exit(status);
1241         return status;
1242 }
1243
1244 /* will give out up to bits_wanted contiguous bits. */
1245 static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
1246                                      struct ocfs2_alloc_context *ac,
1247                                      handle_t *handle,
1248                                      u32 bits_wanted,
1249                                      u32 min_bits,
1250                                      u16 *bit_off,
1251                                      unsigned int *num_bits,
1252                                      u64 *bg_blkno)
1253 {
1254         int status;
1255         u16 victim, i;
1256         u16 bits_left = 0;
1257         u64 hint_blkno = ac->ac_last_group;
1258         struct ocfs2_chain_list *cl;
1259         struct ocfs2_dinode *fe;
1260
1261         mlog_entry_void();
1262
1263         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1264         BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1265         BUG_ON(!ac->ac_bh);
1266
1267         fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1268         if (!OCFS2_IS_VALID_DINODE(fe)) {
1269                 OCFS2_RO_ON_INVALID_DINODE(osb->sb, fe);
1270                 status = -EIO;
1271                 goto bail;
1272         }
1273         if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1274             le32_to_cpu(fe->id1.bitmap1.i_total)) {
1275                 ocfs2_error(osb->sb, "Chain allocator dinode %llu has %u used "
1276                             "bits but only %u total.",
1277                             (unsigned long long)le64_to_cpu(fe->i_blkno),
1278                             le32_to_cpu(fe->id1.bitmap1.i_used),
1279                             le32_to_cpu(fe->id1.bitmap1.i_total));
1280                 status = -EIO;
1281                 goto bail;
1282         }
1283
1284         if (hint_blkno) {
1285                 /* Attempt to short-circuit the usual search mechanism
1286                  * by jumping straight to the most recently used
1287                  * allocation group. This helps us mantain some
1288                  * contiguousness across allocations. */
1289                 status = ocfs2_search_one_group(ac, handle, bits_wanted,
1290                                                 min_bits, bit_off, num_bits,
1291                                                 hint_blkno, &bits_left);
1292                 if (!status) {
1293                         /* Be careful to update *bg_blkno here as the
1294                          * caller is expecting it to be filled in, and
1295                          * ocfs2_search_one_group() won't do that for
1296                          * us. */
1297                         *bg_blkno = hint_blkno;
1298                         goto set_hint;
1299                 }
1300                 if (status < 0 && status != -ENOSPC) {
1301                         mlog_errno(status);
1302                         goto bail;
1303                 }
1304         }
1305
1306         cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1307
1308         victim = ocfs2_find_victim_chain(cl);
1309         ac->ac_chain = victim;
1310         ac->ac_allow_chain_relink = 1;
1311
1312         status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits, bit_off,
1313                                     num_bits, bg_blkno, &bits_left);
1314         if (!status)
1315                 goto set_hint;
1316         if (status < 0 && status != -ENOSPC) {
1317                 mlog_errno(status);
1318                 goto bail;
1319         }
1320
1321         mlog(0, "Search of victim chain %u came up with nothing, "
1322              "trying all chains now.\n", victim);
1323
1324         /* If we didn't pick a good victim, then just default to
1325          * searching each chain in order. Don't allow chain relinking
1326          * because we only calculate enough journal credits for one
1327          * relink per alloc. */
1328         ac->ac_allow_chain_relink = 0;
1329         for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
1330                 if (i == victim)
1331                         continue;
1332                 if (!cl->cl_recs[i].c_free)
1333                         continue;
1334
1335                 ac->ac_chain = i;
1336                 status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1337                                             bit_off, num_bits, bg_blkno,
1338                                             &bits_left);
1339                 if (!status)
1340                         break;
1341                 if (status < 0 && status != -ENOSPC) {
1342                         mlog_errno(status);
1343                         goto bail;
1344                 }
1345         }
1346
1347 set_hint:
1348         if (status != -ENOSPC) {
1349                 /* If the next search of this group is not likely to
1350                  * yield a suitable extent, then we reset the last
1351                  * group hint so as to not waste a disk read */
1352                 if (bits_left < min_bits)
1353                         ac->ac_last_group = 0;
1354                 else
1355                         ac->ac_last_group = *bg_blkno;
1356         }
1357
1358 bail:
1359         mlog_exit(status);
1360         return status;
1361 }
1362
1363 int ocfs2_claim_metadata(struct ocfs2_super *osb,
1364                          handle_t *handle,
1365                          struct ocfs2_alloc_context *ac,
1366                          u32 bits_wanted,
1367                          u16 *suballoc_bit_start,
1368                          unsigned int *num_bits,
1369                          u64 *blkno_start)
1370 {
1371         int status;
1372         u64 bg_blkno;
1373
1374         BUG_ON(!ac);
1375         BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
1376         BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
1377
1378         status = ocfs2_claim_suballoc_bits(osb,
1379                                            ac,
1380                                            handle,
1381                                            bits_wanted,
1382                                            1,
1383                                            suballoc_bit_start,
1384                                            num_bits,
1385                                            &bg_blkno);
1386         if (status < 0) {
1387                 mlog_errno(status);
1388                 goto bail;
1389         }
1390         atomic_inc(&osb->alloc_stats.bg_allocs);
1391
1392         *blkno_start = bg_blkno + (u64) *suballoc_bit_start;
1393         ac->ac_bits_given += (*num_bits);
1394         status = 0;
1395 bail:
1396         mlog_exit(status);
1397         return status;
1398 }
1399
1400 int ocfs2_claim_new_inode(struct ocfs2_super *osb,
1401                           handle_t *handle,
1402                           struct ocfs2_alloc_context *ac,
1403                           u16 *suballoc_bit,
1404                           u64 *fe_blkno)
1405 {
1406         int status;
1407         unsigned int num_bits;
1408         u64 bg_blkno;
1409
1410         mlog_entry_void();
1411
1412         BUG_ON(!ac);
1413         BUG_ON(ac->ac_bits_given != 0);
1414         BUG_ON(ac->ac_bits_wanted != 1);
1415         BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
1416
1417         status = ocfs2_claim_suballoc_bits(osb,
1418                                            ac,
1419                                            handle,
1420                                            1,
1421                                            1,
1422                                            suballoc_bit,
1423                                            &num_bits,
1424                                            &bg_blkno);
1425         if (status < 0) {
1426                 mlog_errno(status);
1427                 goto bail;
1428         }
1429         atomic_inc(&osb->alloc_stats.bg_allocs);
1430
1431         BUG_ON(num_bits != 1);
1432
1433         *fe_blkno = bg_blkno + (u64) (*suballoc_bit);
1434         ac->ac_bits_given++;
1435         status = 0;
1436 bail:
1437         mlog_exit(status);
1438         return status;
1439 }
1440
1441 /* translate a group desc. blkno and it's bitmap offset into
1442  * disk cluster offset. */
1443 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
1444                                                    u64 bg_blkno,
1445                                                    u16 bg_bit_off)
1446 {
1447         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1448         u32 cluster = 0;
1449
1450         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1451
1452         if (bg_blkno != osb->first_cluster_group_blkno)
1453                 cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
1454         cluster += (u32) bg_bit_off;
1455         return cluster;
1456 }
1457
1458 /* given a cluster offset, calculate which block group it belongs to
1459  * and return that block offset. */
1460 static inline u64 ocfs2_which_cluster_group(struct inode *inode,
1461                                             u32 cluster)
1462 {
1463         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1464         u32 group_no;
1465
1466         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1467
1468         group_no = cluster / osb->bitmap_cpg;
1469         if (!group_no)
1470                 return osb->first_cluster_group_blkno;
1471         return ocfs2_clusters_to_blocks(inode->i_sb,
1472                                         group_no * osb->bitmap_cpg);
1473 }
1474
1475 /* given the block number of a cluster start, calculate which cluster
1476  * group and descriptor bitmap offset that corresponds to. */
1477 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
1478                                                 u64 data_blkno,
1479                                                 u64 *bg_blkno,
1480                                                 u16 *bg_bit_off)
1481 {
1482         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1483         u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
1484
1485         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1486
1487         *bg_blkno = ocfs2_which_cluster_group(inode,
1488                                               data_cluster);
1489
1490         if (*bg_blkno == osb->first_cluster_group_blkno)
1491                 *bg_bit_off = (u16) data_cluster;
1492         else
1493                 *bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
1494                                                              data_blkno - *bg_blkno);
1495 }
1496
1497 /*
1498  * min_bits - minimum contiguous chunk from this total allocation we
1499  * can handle. set to what we asked for originally for a full
1500  * contig. allocation, set to '1' to indicate we can deal with extents
1501  * of any size.
1502  */
1503 int ocfs2_claim_clusters(struct ocfs2_super *osb,
1504                          handle_t *handle,
1505                          struct ocfs2_alloc_context *ac,
1506                          u32 min_clusters,
1507                          u32 *cluster_start,
1508                          u32 *num_clusters)
1509 {
1510         int status;
1511         unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
1512         u64 bg_blkno = 0;
1513         u16 bg_bit_off;
1514
1515         mlog_entry_void();
1516
1517         BUG_ON(!ac);
1518         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1519
1520         BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
1521                && ac->ac_which != OCFS2_AC_USE_MAIN);
1522
1523         if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
1524                 status = ocfs2_claim_local_alloc_bits(osb,
1525                                                       handle,
1526                                                       ac,
1527                                                       bits_wanted,
1528                                                       cluster_start,
1529                                                       num_clusters);
1530                 if (!status)
1531                         atomic_inc(&osb->alloc_stats.local_data);
1532         } else {
1533                 if (min_clusters > (osb->bitmap_cpg - 1)) {
1534                         /* The only paths asking for contiguousness
1535                          * should know about this already. */
1536                         mlog(ML_ERROR, "minimum allocation requested exceeds "
1537                                        "group bitmap size!");
1538                         status = -ENOSPC;
1539                         goto bail;
1540                 }
1541                 /* clamp the current request down to a realistic size. */
1542                 if (bits_wanted > (osb->bitmap_cpg - 1))
1543                         bits_wanted = osb->bitmap_cpg - 1;
1544
1545                 status = ocfs2_claim_suballoc_bits(osb,
1546                                                    ac,
1547                                                    handle,
1548                                                    bits_wanted,
1549                                                    min_clusters,
1550                                                    &bg_bit_off,
1551                                                    num_clusters,
1552                                                    &bg_blkno);
1553                 if (!status) {
1554                         *cluster_start =
1555                                 ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
1556                                                                  bg_blkno,
1557                                                                  bg_bit_off);
1558                         atomic_inc(&osb->alloc_stats.bitmap_data);
1559                 }
1560         }
1561         if (status < 0) {
1562                 if (status != -ENOSPC)
1563                         mlog_errno(status);
1564                 goto bail;
1565         }
1566
1567         ac->ac_bits_given += *num_clusters;
1568
1569 bail:
1570         mlog_exit(status);
1571         return status;
1572 }
1573
1574 static inline int ocfs2_block_group_clear_bits(handle_t *handle,
1575                                                struct inode *alloc_inode,
1576                                                struct ocfs2_group_desc *bg,
1577                                                struct buffer_head *group_bh,
1578                                                unsigned int bit_off,
1579                                                unsigned int num_bits)
1580 {
1581         int status;
1582         unsigned int tmp;
1583         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1584         struct ocfs2_group_desc *undo_bg = NULL;
1585
1586         mlog_entry_void();
1587
1588         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
1589                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
1590                 status = -EIO;
1591                 goto bail;
1592         }
1593
1594         mlog(0, "off = %u, num = %u\n", bit_off, num_bits);
1595
1596         if (ocfs2_is_cluster_bitmap(alloc_inode))
1597                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1598
1599         status = ocfs2_journal_access(handle, alloc_inode, group_bh,
1600                                       journal_type);
1601         if (status < 0) {
1602                 mlog_errno(status);
1603                 goto bail;
1604         }
1605
1606         if (ocfs2_is_cluster_bitmap(alloc_inode))
1607                 undo_bg = (struct ocfs2_group_desc *) bh2jh(group_bh)->b_committed_data;
1608
1609         tmp = num_bits;
1610         while(tmp--) {
1611                 ocfs2_clear_bit((bit_off + tmp),
1612                                 (unsigned long *) bg->bg_bitmap);
1613                 if (ocfs2_is_cluster_bitmap(alloc_inode))
1614                         ocfs2_set_bit(bit_off + tmp,
1615                                       (unsigned long *) undo_bg->bg_bitmap);
1616         }
1617         le16_add_cpu(&bg->bg_free_bits_count, num_bits);
1618
1619         status = ocfs2_journal_dirty(handle, group_bh);
1620         if (status < 0)
1621                 mlog_errno(status);
1622 bail:
1623         return status;
1624 }
1625
1626 /*
1627  * expects the suballoc inode to already be locked.
1628  */
1629 static int ocfs2_free_suballoc_bits(handle_t *handle,
1630                                     struct inode *alloc_inode,
1631                                     struct buffer_head *alloc_bh,
1632                                     unsigned int start_bit,
1633                                     u64 bg_blkno,
1634                                     unsigned int count)
1635 {
1636         int status = 0;
1637         u32 tmp_used;
1638         struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
1639         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
1640         struct ocfs2_chain_list *cl = &fe->id2.i_chain;
1641         struct buffer_head *group_bh = NULL;
1642         struct ocfs2_group_desc *group;
1643
1644         mlog_entry_void();
1645
1646         if (!OCFS2_IS_VALID_DINODE(fe)) {
1647                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
1648                 status = -EIO;
1649                 goto bail;
1650         }
1651         BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
1652
1653         mlog(0, "%llu: freeing %u bits from group %llu, starting at %u\n",
1654              (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno, count,
1655              (unsigned long long)bg_blkno, start_bit);
1656
1657         status = ocfs2_read_block(osb, bg_blkno, &group_bh, OCFS2_BH_CACHED,
1658                                   alloc_inode);
1659         if (status < 0) {
1660                 mlog_errno(status);
1661                 goto bail;
1662         }
1663
1664         group = (struct ocfs2_group_desc *) group_bh->b_data;
1665         status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, group);
1666         if (status) {
1667                 mlog_errno(status);
1668                 goto bail;
1669         }
1670         BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
1671
1672         status = ocfs2_block_group_clear_bits(handle, alloc_inode,
1673                                               group, group_bh,
1674                                               start_bit, count);
1675         if (status < 0) {
1676                 mlog_errno(status);
1677                 goto bail;
1678         }
1679
1680         status = ocfs2_journal_access(handle, alloc_inode, alloc_bh,
1681                                       OCFS2_JOURNAL_ACCESS_WRITE);
1682         if (status < 0) {
1683                 mlog_errno(status);
1684                 goto bail;
1685         }
1686
1687         le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
1688                      count);
1689         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
1690         fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
1691
1692         status = ocfs2_journal_dirty(handle, alloc_bh);
1693         if (status < 0) {
1694                 mlog_errno(status);
1695                 goto bail;
1696         }
1697
1698 bail:
1699         if (group_bh)
1700                 brelse(group_bh);
1701
1702         mlog_exit(status);
1703         return status;
1704 }
1705
1706 static inline u64 ocfs2_which_suballoc_group(u64 block, unsigned int bit)
1707 {
1708         u64 group = block - (u64) bit;
1709
1710         return group;
1711 }
1712
1713 int ocfs2_free_dinode(handle_t *handle,
1714                       struct inode *inode_alloc_inode,
1715                       struct buffer_head *inode_alloc_bh,
1716                       struct ocfs2_dinode *di)
1717 {
1718         u64 blk = le64_to_cpu(di->i_blkno);
1719         u16 bit = le16_to_cpu(di->i_suballoc_bit);
1720         u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
1721
1722         return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
1723                                         inode_alloc_bh, bit, bg_blkno, 1);
1724 }
1725
1726 int ocfs2_free_extent_block(handle_t *handle,
1727                             struct inode *eb_alloc_inode,
1728                             struct buffer_head *eb_alloc_bh,
1729                             struct ocfs2_extent_block *eb)
1730 {
1731         u64 blk = le64_to_cpu(eb->h_blkno);
1732         u16 bit = le16_to_cpu(eb->h_suballoc_bit);
1733         u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
1734
1735         return ocfs2_free_suballoc_bits(handle, eb_alloc_inode, eb_alloc_bh,
1736                                         bit, bg_blkno, 1);
1737 }
1738
1739 int ocfs2_free_clusters(handle_t *handle,
1740                        struct inode *bitmap_inode,
1741                        struct buffer_head *bitmap_bh,
1742                        u64 start_blk,
1743                        unsigned int num_clusters)
1744 {
1745         int status;
1746         u16 bg_start_bit;
1747         u64 bg_blkno;
1748         struct ocfs2_dinode *fe;
1749
1750         /* You can't ever have a contiguous set of clusters
1751          * bigger than a block group bitmap so we never have to worry
1752          * about looping on them. */
1753
1754         mlog_entry_void();
1755
1756         /* This is expensive. We can safely remove once this stuff has
1757          * gotten tested really well. */
1758         BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb, ocfs2_blocks_to_clusters(bitmap_inode->i_sb, start_blk)));
1759
1760         fe = (struct ocfs2_dinode *) bitmap_bh->b_data;
1761
1762         ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
1763                                      &bg_start_bit);
1764
1765         mlog(0, "want to free %u clusters starting at block %llu\n",
1766              num_clusters, (unsigned long long)start_blk);
1767         mlog(0, "bg_blkno = %llu, bg_start_bit = %u\n",
1768              (unsigned long long)bg_blkno, bg_start_bit);
1769
1770         status = ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
1771                                           bg_start_bit, bg_blkno,
1772                                           num_clusters);
1773         if (status < 0)
1774                 mlog_errno(status);
1775
1776         mlog_exit(status);
1777         return status;
1778 }
1779
1780 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg)
1781 {
1782         printk("Block Group:\n");
1783         printk("bg_signature:       %s\n", bg->bg_signature);
1784         printk("bg_size:            %u\n", bg->bg_size);
1785         printk("bg_bits:            %u\n", bg->bg_bits);
1786         printk("bg_free_bits_count: %u\n", bg->bg_free_bits_count);
1787         printk("bg_chain:           %u\n", bg->bg_chain);
1788         printk("bg_generation:      %u\n", le32_to_cpu(bg->bg_generation));
1789         printk("bg_next_group:      %llu\n",
1790                (unsigned long long)bg->bg_next_group);
1791         printk("bg_parent_dinode:   %llu\n",
1792                (unsigned long long)bg->bg_parent_dinode);
1793         printk("bg_blkno:           %llu\n",
1794                (unsigned long long)bg->bg_blkno);
1795 }
1796
1797 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe)
1798 {
1799         int i;
1800
1801         printk("Suballoc Inode %llu:\n", (unsigned long long)fe->i_blkno);
1802         printk("i_signature:                  %s\n", fe->i_signature);
1803         printk("i_size:                       %llu\n",
1804                (unsigned long long)fe->i_size);
1805         printk("i_clusters:                   %u\n", fe->i_clusters);
1806         printk("i_generation:                 %u\n",
1807                le32_to_cpu(fe->i_generation));
1808         printk("id1.bitmap1.i_used:           %u\n",
1809                le32_to_cpu(fe->id1.bitmap1.i_used));
1810         printk("id1.bitmap1.i_total:          %u\n",
1811                le32_to_cpu(fe->id1.bitmap1.i_total));
1812         printk("id2.i_chain.cl_cpg:           %u\n", fe->id2.i_chain.cl_cpg);
1813         printk("id2.i_chain.cl_bpc:           %u\n", fe->id2.i_chain.cl_bpc);
1814         printk("id2.i_chain.cl_count:         %u\n", fe->id2.i_chain.cl_count);
1815         printk("id2.i_chain.cl_next_free_rec: %u\n",
1816                fe->id2.i_chain.cl_next_free_rec);
1817         for(i = 0; i < fe->id2.i_chain.cl_next_free_rec; i++) {
1818                 printk("fe->id2.i_chain.cl_recs[%d].c_free:  %u\n", i,
1819                        fe->id2.i_chain.cl_recs[i].c_free);
1820                 printk("fe->id2.i_chain.cl_recs[%d].c_total: %u\n", i,
1821                        fe->id2.i_chain.cl_recs[i].c_total);
1822                 printk("fe->id2.i_chain.cl_recs[%d].c_blkno: %llu\n", i,
1823                        (unsigned long long)fe->id2.i_chain.cl_recs[i].c_blkno);
1824         }
1825 }