git.oblomov.eu Git - linux-2.6/blob - 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 #define NOT_ALLOC_NEW_GROUP             0
  50 #define ALLOC_NEW_GROUP                 1
  51
  52 #define OCFS2_MAX_INODES_TO_STEAL       1024
  53
  54 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg);
  55 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe);
  56 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl);
  57 static int ocfs2_block_group_fill(handle_t *handle,
  58                                   struct inode *alloc_inode,
  59                                   struct buffer_head *bg_bh,
  60                                   u64 group_blkno,
  61                                   u16 my_chain,
  62                                   struct ocfs2_chain_list *cl);
  63 static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
  64                                    struct inode *alloc_inode,
  65                                    struct buffer_head *bh,
  66                                    u64 max_block);
  67
  68 static int ocfs2_cluster_group_search(struct inode *inode,
  69                                       struct buffer_head *group_bh,
  70                                       u32 bits_wanted, u32 min_bits,
  71                                       u64 max_block,
  72                                       u16 *bit_off, u16 *bits_found);
  73 static int ocfs2_block_group_search(struct inode *inode,
  74                                     struct buffer_head *group_bh,
  75                                     u32 bits_wanted, u32 min_bits,
  76                                     u64 max_block,
  77                                     u16 *bit_off, u16 *bits_found);
  78 static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
  79                                      struct ocfs2_alloc_context *ac,
  80                                      handle_t *handle,
  81                                      u32 bits_wanted,
  82                                      u32 min_bits,
  83                                      u16 *bit_off,
  84                                      unsigned int *num_bits,
  85                                      u64 *bg_blkno);
  86 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
  87                                          int nr);
  88 static inline int ocfs2_block_group_set_bits(handle_t *handle,
  89                                              struct inode *alloc_inode,
  90                                              struct ocfs2_group_desc *bg,
  91                                              struct buffer_head *group_bh,
  92                                              unsigned int bit_off,
  93                                              unsigned int num_bits);
  94 static inline int ocfs2_block_group_clear_bits(handle_t *handle,
  95                                                struct inode *alloc_inode,
  96                                                struct ocfs2_group_desc *bg,
  97                                                struct buffer_head *group_bh,
  98                                                unsigned int bit_off,
  99                                                unsigned int num_bits);
 100
 101 static int ocfs2_relink_block_group(handle_t *handle,
 102                                     struct inode *alloc_inode,
 103                                     struct buffer_head *fe_bh,
 104                                     struct buffer_head *bg_bh,
 105                                     struct buffer_head *prev_bg_bh,
 106                                     u16 chain);
 107 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
 108                                                      u32 wanted);
 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 void ocfs2_block_to_cluster_group(struct inode *inode,
 113                                                 u64 data_blkno,
 114                                                 u64 *bg_blkno,
 115                                                 u16 *bg_bit_off);
 116 static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
 117                                              u32 bits_wanted, u64 max_block,
 118                                              struct ocfs2_alloc_context **ac);
 119
 120 void ocfs2_free_ac_resource(struct ocfs2_alloc_context *ac)
 121 {
 122         struct inode *inode = ac->ac_inode;
 123
 124         if (inode) {
 125                 if (ac->ac_which != OCFS2_AC_USE_LOCAL)
 126                         ocfs2_inode_unlock(inode, 1);
 127
 128                 mutex_unlock(&inode->i_mutex);
 129
 130                 iput(inode);
 131                 ac->ac_inode = NULL;
 132         }
 133         if (ac->ac_bh) {
 134                 brelse(ac->ac_bh);
 135                 ac->ac_bh = NULL;
 136         }
 137 }
 138
 139 void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
 140 {
 141         ocfs2_free_ac_resource(ac);
 142         kfree(ac);
 143 }
 144
 145 static u32 ocfs2_bits_per_group(struct ocfs2_chain_list *cl)
 146 {
 147         return (u32)le16_to_cpu(cl->cl_cpg) * (u32)le16_to_cpu(cl->cl_bpc);
 148 }
 149
 150 /* somewhat more expensive than our other checks, so use sparingly. */
 151 int ocfs2_check_group_descriptor(struct super_block *sb,
 152                                  struct ocfs2_dinode *di,
 153                                  struct ocfs2_group_desc *gd)
 154 {
 155         unsigned int max_bits;
 156
 157         if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
 158                 OCFS2_RO_ON_INVALID_GROUP_DESC(sb, gd);
 159                 return -EIO;
 160         }
 161
 162         if (di->i_blkno != gd->bg_parent_dinode) {
 163                 ocfs2_error(sb, "Group descriptor # %llu has bad parent "
 164                             "pointer (%llu, expected %llu)",
 165                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 166                             (unsigned long long)le64_to_cpu(gd->bg_parent_dinode),
 167                             (unsigned long long)le64_to_cpu(di->i_blkno));
 168                 return -EIO;
 169         }
 170
 171         max_bits = le16_to_cpu(di->id2.i_chain.cl_cpg) * le16_to_cpu(di->id2.i_chain.cl_bpc);
 172         if (le16_to_cpu(gd->bg_bits) > max_bits) {
 173                 ocfs2_error(sb, "Group descriptor # %llu has bit count of %u",
 174                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 175                             le16_to_cpu(gd->bg_bits));
 176                 return -EIO;
 177         }
 178
 179         if (le16_to_cpu(gd->bg_chain) >=
 180             le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) {
 181                 ocfs2_error(sb, "Group descriptor # %llu has bad chain %u",
 182                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 183                             le16_to_cpu(gd->bg_chain));
 184                 return -EIO;
 185         }
 186
 187         if (le16_to_cpu(gd->bg_free_bits_count) > le16_to_cpu(gd->bg_bits)) {
 188                 ocfs2_error(sb, "Group descriptor # %llu has bit count %u but "
 189                             "claims that %u are free",
 190                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 191                             le16_to_cpu(gd->bg_bits),
 192                             le16_to_cpu(gd->bg_free_bits_count));
 193                 return -EIO;
 194         }
 195
 196         if (le16_to_cpu(gd->bg_bits) > (8 * le16_to_cpu(gd->bg_size))) {
 197                 ocfs2_error(sb, "Group descriptor # %llu has bit count %u but "
 198                             "max bitmap bits of %u",
 199                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 200                             le16_to_cpu(gd->bg_bits),
 201                             8 * le16_to_cpu(gd->bg_size));
 202                 return -EIO;
 203         }
 204
 205         return 0;
 206 }
 207
 208 static int ocfs2_block_group_fill(handle_t *handle,
 209                                   struct inode *alloc_inode,
 210                                   struct buffer_head *bg_bh,
 211                                   u64 group_blkno,
 212                                   u16 my_chain,
 213                                   struct ocfs2_chain_list *cl)
 214 {
 215         int status = 0;
 216         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 217         struct super_block * sb = alloc_inode->i_sb;
 218
 219         mlog_entry_void();
 220
 221         if (((unsigned long long) bg_bh->b_blocknr) != group_blkno) {
 222                 ocfs2_error(alloc_inode->i_sb, "group block (%llu) != "
 223                             "b_blocknr (%llu)",
 224                             (unsigned long long)group_blkno,
 225                             (unsigned long long) bg_bh->b_blocknr);
 226                 status = -EIO;
 227                 goto bail;
 228         }
 229
 230         status = ocfs2_journal_access(handle,
 231                                       alloc_inode,
 232                                       bg_bh,
 233                                       OCFS2_JOURNAL_ACCESS_CREATE);
 234         if (status < 0) {
 235                 mlog_errno(status);
 236                 goto bail;
 237         }
 238
 239         memset(bg, 0, sb->s_blocksize);
 240         strcpy(bg->bg_signature, OCFS2_GROUP_DESC_SIGNATURE);
 241         bg->bg_generation = cpu_to_le32(OCFS2_SB(sb)->fs_generation);
 242         bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb));
 243         bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
 244         bg->bg_chain = cpu_to_le16(my_chain);
 245         bg->bg_next_group = cl->cl_recs[my_chain].c_blkno;
 246         bg->bg_parent_dinode = cpu_to_le64(OCFS2_I(alloc_inode)->ip_blkno);
 247         bg->bg_blkno = cpu_to_le64(group_blkno);
 248         /* set the 1st bit in the bitmap to account for the descriptor block */
 249         ocfs2_set_bit(0, (unsigned long *)bg->bg_bitmap);
 250         bg->bg_free_bits_count = cpu_to_le16(le16_to_cpu(bg->bg_bits) - 1);
 251
 252         status = ocfs2_journal_dirty(handle, bg_bh);
 253         if (status < 0)
 254                 mlog_errno(status);
 255
 256         /* There is no need to zero out or otherwise initialize the
 257          * other blocks in a group - All valid FS metadata in a block
 258          * group stores the superblock fs_generation value at
 259          * allocation time. */
 260
 261 bail:
 262         mlog_exit(status);
 263         return status;
 264 }
 265
 266 static inline u16 ocfs2_find_smallest_chain(struct ocfs2_chain_list *cl)
 267 {
 268         u16 curr, best;
 269
 270         best = curr = 0;
 271         while (curr < le16_to_cpu(cl->cl_count)) {
 272                 if (le32_to_cpu(cl->cl_recs[best].c_total) >
 273                     le32_to_cpu(cl->cl_recs[curr].c_total))
 274                         best = curr;
 275                 curr++;
 276         }
 277         return best;
 278 }
 279
 280 /*
 281  * We expect the block group allocator to already be locked.
 282  */
 283 static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
 284                                    struct inode *alloc_inode,
 285                                    struct buffer_head *bh,
 286                                    u64 max_block)
 287 {
 288         int status, credits;
 289         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) bh->b_data;
 290         struct ocfs2_chain_list *cl;
 291         struct ocfs2_alloc_context *ac = NULL;
 292         handle_t *handle = NULL;
 293         u32 bit_off, num_bits;
 294         u16 alloc_rec;
 295         u64 bg_blkno;
 296         struct buffer_head *bg_bh = NULL;
 297         struct ocfs2_group_desc *bg;
 298
 299         BUG_ON(ocfs2_is_cluster_bitmap(alloc_inode));
 300
 301         mlog_entry_void();
 302
 303         cl = &fe->id2.i_chain;
 304         status = ocfs2_reserve_clusters_with_limit(osb,
 305                                                    le16_to_cpu(cl->cl_cpg),
 306                                                    max_block, &ac);
 307         if (status < 0) {
 308                 if (status != -ENOSPC)
 309                         mlog_errno(status);
 310                 goto bail;
 311         }
 312
 313         credits = ocfs2_calc_group_alloc_credits(osb->sb,
 314                                                  le16_to_cpu(cl->cl_cpg));
 315         handle = ocfs2_start_trans(osb, credits);
 316         if (IS_ERR(handle)) {
 317                 status = PTR_ERR(handle);
 318                 handle = NULL;
 319                 mlog_errno(status);
 320                 goto bail;
 321         }
 322
 323         status = ocfs2_claim_clusters(osb,
 324                                       handle,
 325                                       ac,
 326                                       le16_to_cpu(cl->cl_cpg),
 327                                       &bit_off,
 328                                       &num_bits);
 329         if (status < 0) {
 330                 if (status != -ENOSPC)
 331                         mlog_errno(status);
 332                 goto bail;
 333         }
 334
 335         alloc_rec = ocfs2_find_smallest_chain(cl);
 336
 337         /* setup the group */
 338         bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 339         mlog(0, "new descriptor, record %u, at block %llu\n",
 340              alloc_rec, (unsigned long long)bg_blkno);
 341
 342         bg_bh = sb_getblk(osb->sb, bg_blkno);
 343         if (!bg_bh) {
 344                 status = -EIO;
 345                 mlog_errno(status);
 346                 goto bail;
 347         }
 348         ocfs2_set_new_buffer_uptodate(alloc_inode, bg_bh);
 349
 350         status = ocfs2_block_group_fill(handle,
 351                                         alloc_inode,
 352                                         bg_bh,
 353                                         bg_blkno,
 354                                         alloc_rec,
 355                                         cl);
 356         if (status < 0) {
 357                 mlog_errno(status);
 358                 goto bail;
 359         }
 360
 361         bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 362
 363         status = ocfs2_journal_access(handle, alloc_inode,
 364                                       bh, OCFS2_JOURNAL_ACCESS_WRITE);
 365         if (status < 0) {
 366                 mlog_errno(status);
 367                 goto bail;
 368         }
 369
 370         le32_add_cpu(&cl->cl_recs[alloc_rec].c_free,
 371                      le16_to_cpu(bg->bg_free_bits_count));
 372         le32_add_cpu(&cl->cl_recs[alloc_rec].c_total, le16_to_cpu(bg->bg_bits));
 373         cl->cl_recs[alloc_rec].c_blkno  = cpu_to_le64(bg_blkno);
 374         if (le16_to_cpu(cl->cl_next_free_rec) < le16_to_cpu(cl->cl_count))
 375                 le16_add_cpu(&cl->cl_next_free_rec, 1);
 376
 377         le32_add_cpu(&fe->id1.bitmap1.i_used, le16_to_cpu(bg->bg_bits) -
 378                                         le16_to_cpu(bg->bg_free_bits_count));
 379         le32_add_cpu(&fe->id1.bitmap1.i_total, le16_to_cpu(bg->bg_bits));
 380         le32_add_cpu(&fe->i_clusters, le16_to_cpu(cl->cl_cpg));
 381
 382         status = ocfs2_journal_dirty(handle, bh);
 383         if (status < 0) {
 384                 mlog_errno(status);
 385                 goto bail;
 386         }
 387
 388         spin_lock(&OCFS2_I(alloc_inode)->ip_lock);
 389         OCFS2_I(alloc_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
 390         fe->i_size = cpu_to_le64(ocfs2_clusters_to_bytes(alloc_inode->i_sb,
 391                                              le32_to_cpu(fe->i_clusters)));
 392         spin_unlock(&OCFS2_I(alloc_inode)->ip_lock);
 393         i_size_write(alloc_inode, le64_to_cpu(fe->i_size));
 394         alloc_inode->i_blocks = ocfs2_inode_sector_count(alloc_inode);
 395
 396         status = 0;
 397 bail:
 398         if (handle)
 399                 ocfs2_commit_trans(osb, handle);
 400
 401         if (ac)
 402                 ocfs2_free_alloc_context(ac);
 403
 404         if (bg_bh)
 405                 brelse(bg_bh);
 406
 407         mlog_exit(status);
 408         return status;
 409 }
 410
 411 static int ocfs2_reserve_suballoc_bits(struct ocfs2_super *osb,
 412                                        struct ocfs2_alloc_context *ac,
 413                                        int type,
 414                                        u32 slot,
 415                                        int alloc_new_group)
 416 {
 417         int status;
 418         u32 bits_wanted = ac->ac_bits_wanted;
 419         struct inode *alloc_inode;
 420         struct buffer_head *bh = NULL;
 421         struct ocfs2_dinode *fe;
 422         u32 free_bits;
 423
 424         mlog_entry_void();
 425
 426         alloc_inode = ocfs2_get_system_file_inode(osb, type, slot);
 427         if (!alloc_inode) {
 428                 mlog_errno(-EINVAL);
 429                 return -EINVAL;
 430         }
 431
 432         mutex_lock(&alloc_inode->i_mutex);
 433
 434         status = ocfs2_inode_lock(alloc_inode, &bh, 1);
 435         if (status < 0) {
 436                 mutex_unlock(&alloc_inode->i_mutex);
 437                 iput(alloc_inode);
 438
 439                 mlog_errno(status);
 440                 return status;
 441         }
 442
 443         ac->ac_inode = alloc_inode;
 444         ac->ac_alloc_slot = slot;
 445
 446         fe = (struct ocfs2_dinode *) bh->b_data;
 447         if (!OCFS2_IS_VALID_DINODE(fe)) {
 448                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
 449                 status = -EIO;
 450                 goto bail;
 451         }
 452         if (!(fe->i_flags & cpu_to_le32(OCFS2_CHAIN_FL))) {
 453                 ocfs2_error(alloc_inode->i_sb, "Invalid chain allocator %llu",
 454                             (unsigned long long)le64_to_cpu(fe->i_blkno));
 455                 status = -EIO;
 456                 goto bail;
 457         }
 458
 459         free_bits = le32_to_cpu(fe->id1.bitmap1.i_total) -
 460                 le32_to_cpu(fe->id1.bitmap1.i_used);
 461
 462         if (bits_wanted > free_bits) {
 463                 /* cluster bitmap never grows */
 464                 if (ocfs2_is_cluster_bitmap(alloc_inode)) {
 465                         mlog(0, "Disk Full: wanted=%u, free_bits=%u\n",
 466                              bits_wanted, free_bits);
 467                         status = -ENOSPC;
 468                         goto bail;
 469                 }
 470
 471                 if (alloc_new_group != ALLOC_NEW_GROUP) {
 472                         mlog(0, "Alloc File %u Full: wanted=%u, free_bits=%u, "
 473                              "and we don't alloc a new group for it.\n",
 474                              slot, bits_wanted, free_bits);
 475                         status = -ENOSPC;
 476                         goto bail;
 477                 }
 478
 479                 status = ocfs2_block_group_alloc(osb, alloc_inode, bh,
 480                                                  ac->ac_max_block);
 481                 if (status < 0) {
 482                         if (status != -ENOSPC)
 483                                 mlog_errno(status);
 484                         goto bail;
 485                 }
 486                 atomic_inc(&osb->alloc_stats.bg_extends);
 487
 488                 /* You should never ask for this much metadata */
 489                 BUG_ON(bits_wanted >
 490                        (le32_to_cpu(fe->id1.bitmap1.i_total)
 491                         - le32_to_cpu(fe->id1.bitmap1.i_used)));
 492         }
 493
 494         get_bh(bh);
 495         ac->ac_bh = bh;
 496 bail:
 497         if (bh)
 498                 brelse(bh);
 499
 500         mlog_exit(status);
 501         return status;
 502 }
 503
 504 int ocfs2_reserve_new_metadata_blocks(struct ocfs2_super *osb,
 505                                       int blocks,
 506                                       struct ocfs2_alloc_context **ac)
 507 {
 508         int status;
 509         u32 slot;
 510
 511         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 512         if (!(*ac)) {
 513                 status = -ENOMEM;
 514                 mlog_errno(status);
 515                 goto bail;
 516         }
 517
 518         (*ac)->ac_bits_wanted = blocks;
 519         (*ac)->ac_which = OCFS2_AC_USE_META;
 520         slot = osb->slot_num;
 521         (*ac)->ac_group_search = ocfs2_block_group_search;
 522
 523         status = ocfs2_reserve_suballoc_bits(osb, (*ac),
 524                                              EXTENT_ALLOC_SYSTEM_INODE,
 525                                              slot, ALLOC_NEW_GROUP);
 526         if (status < 0) {
 527                 if (status != -ENOSPC)
 528                         mlog_errno(status);
 529                 goto bail;
 530         }
 531
 532         status = 0;
 533 bail:
 534         if ((status < 0) && *ac) {
 535                 ocfs2_free_alloc_context(*ac);
 536                 *ac = NULL;
 537         }
 538
 539         mlog_exit(status);
 540         return status;
 541 }
 542
 543 int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
 544                                struct ocfs2_extent_list *root_el,
 545                                struct ocfs2_alloc_context **ac)
 546 {
 547         return ocfs2_reserve_new_metadata_blocks(osb,
 548                                         ocfs2_extend_meta_needed(root_el),
 549                                         ac);
 550 }
 551
 552 static int ocfs2_steal_inode_from_other_nodes(struct ocfs2_super *osb,
 553                                               struct ocfs2_alloc_context *ac)
 554 {
 555         int i, status = -ENOSPC;
 556         s16 slot = ocfs2_get_inode_steal_slot(osb);
 557
 558         /* Start to steal inodes from the first slot after ours. */
 559         if (slot == OCFS2_INVALID_SLOT)
 560                 slot = osb->slot_num + 1;
 561
 562         for (i = 0; i < osb->max_slots; i++, slot++) {
 563                 if (slot == osb->max_slots)
 564                         slot = 0;
 565
 566                 if (slot == osb->slot_num)
 567                         continue;
 568
 569                 status = ocfs2_reserve_suballoc_bits(osb, ac,
 570                                                      INODE_ALLOC_SYSTEM_INODE,
 571                                                      slot, NOT_ALLOC_NEW_GROUP);
 572                 if (status >= 0) {
 573                         ocfs2_set_inode_steal_slot(osb, slot);
 574                         break;
 575                 }
 576
 577                 ocfs2_free_ac_resource(ac);
 578         }
 579
 580         return status;
 581 }
 582
 583 int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
 584                             struct ocfs2_alloc_context **ac)
 585 {
 586         int status;
 587         s16 slot = ocfs2_get_inode_steal_slot(osb);
 588
 589         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 590         if (!(*ac)) {
 591                 status = -ENOMEM;
 592                 mlog_errno(status);
 593                 goto bail;
 594         }
 595
 596         (*ac)->ac_bits_wanted = 1;
 597         (*ac)->ac_which = OCFS2_AC_USE_INODE;
 598
 599         (*ac)->ac_group_search = ocfs2_block_group_search;
 600
 601         /*
 602          * stat(2) can't handle i_ino > 32bits, so we tell the
 603          * lower levels not to allocate us a block group past that
 604          * limit.
 605          */
 606         (*ac)->ac_max_block = (u32)~0U;
 607
 608         /*
 609          * slot is set when we successfully steal inode from other nodes.
 610          * It is reset in 3 places:
 611          * 1. when we flush the truncate log
 612          * 2. when we complete local alloc recovery.
 613          * 3. when we successfully allocate from our own slot.
 614          * After it is set, we will go on stealing inodes until we find the
 615          * need to check our slots to see whether there is some space for us.
 616          */
 617         if (slot != OCFS2_INVALID_SLOT &&
 618             atomic_read(&osb->s_num_inodes_stolen) < OCFS2_MAX_INODES_TO_STEAL)
 619                 goto inode_steal;
 620
 621         atomic_set(&osb->s_num_inodes_stolen, 0);
 622         status = ocfs2_reserve_suballoc_bits(osb, *ac,
 623                                              INODE_ALLOC_SYSTEM_INODE,
 624                                              osb->slot_num, ALLOC_NEW_GROUP);
 625         if (status >= 0) {
 626                 status = 0;
 627
 628                 /*
 629                  * Some inodes must be freed by us, so try to allocate
 630                  * from our own next time.
 631                  */
 632                 if (slot != OCFS2_INVALID_SLOT)
 633                         ocfs2_init_inode_steal_slot(osb);
 634                 goto bail;
 635         } else if (status < 0 && status != -ENOSPC) {
 636                 mlog_errno(status);
 637                 goto bail;
 638         }
 639
 640         ocfs2_free_ac_resource(*ac);
 641
 642 inode_steal:
 643         status = ocfs2_steal_inode_from_other_nodes(osb, *ac);
 644         atomic_inc(&osb->s_num_inodes_stolen);
 645         if (status < 0) {
 646                 if (status != -ENOSPC)
 647                         mlog_errno(status);
 648                 goto bail;
 649         }
 650
 651         status = 0;
 652 bail:
 653         if ((status < 0) && *ac) {
 654                 ocfs2_free_alloc_context(*ac);
 655                 *ac = NULL;
 656         }
 657
 658         mlog_exit(status);
 659         return status;
 660 }
 661
 662 /* local alloc code has to do the same thing, so rather than do this
 663  * twice.. */
 664 int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
 665                                       struct ocfs2_alloc_context *ac)
 666 {
 667         int status;
 668
 669         ac->ac_which = OCFS2_AC_USE_MAIN;
 670         ac->ac_group_search = ocfs2_cluster_group_search;
 671
 672         status = ocfs2_reserve_suballoc_bits(osb, ac,
 673                                              GLOBAL_BITMAP_SYSTEM_INODE,
 674                                              OCFS2_INVALID_SLOT,
 675                                              ALLOC_NEW_GROUP);
 676         if (status < 0 && status != -ENOSPC) {
 677                 mlog_errno(status);
 678                 goto bail;
 679         }
 680
 681 bail:
 682         return status;
 683 }
 684
 685 /* Callers don't need to care which bitmap (local alloc or main) to
 686  * use so we figure it out for them, but unfortunately this clutters
 687  * things a bit. */
 688 static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
 689                                              u32 bits_wanted, u64 max_block,
 690                                              struct ocfs2_alloc_context **ac)
 691 {
 692         int status;
 693
 694         mlog_entry_void();
 695
 696         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 697         if (!(*ac)) {
 698                 status = -ENOMEM;
 699                 mlog_errno(status);
 700                 goto bail;
 701         }
 702
 703         (*ac)->ac_bits_wanted = bits_wanted;
 704         (*ac)->ac_max_block = max_block;
 705
 706         status = -ENOSPC;
 707         if (ocfs2_alloc_should_use_local(osb, bits_wanted)) {
 708                 status = ocfs2_reserve_local_alloc_bits(osb,
 709                                                         bits_wanted,
 710                                                         *ac);
 711                 if (status == -EFBIG) {
 712                         /* The local alloc window is outside ac_max_block.
 713                          * use the main bitmap. */
 714                         status = -ENOSPC;
 715                 } else if ((status < 0) && (status != -ENOSPC)) {
 716                         mlog_errno(status);
 717                         goto bail;
 718                 }
 719         }
 720
 721         if (status == -ENOSPC) {
 722                 status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
 723                 if (status < 0) {
 724                         if (status != -ENOSPC)
 725                                 mlog_errno(status);
 726                         goto bail;
 727                 }
 728         }
 729
 730         status = 0;
 731 bail:
 732         if ((status < 0) && *ac) {
 733                 ocfs2_free_alloc_context(*ac);
 734                 *ac = NULL;
 735         }
 736
 737         mlog_exit(status);
 738         return status;
 739 }
 740
 741 int ocfs2_reserve_clusters(struct ocfs2_super *osb,
 742                            u32 bits_wanted,
 743                            struct ocfs2_alloc_context **ac)
 744 {
 745         return ocfs2_reserve_clusters_with_limit(osb, bits_wanted, 0, ac);
 746 }
 747
 748 /*
 749  * More or less lifted from ext3. I'll leave their description below:
 750  *
 751  * "For ext3 allocations, we must not reuse any blocks which are
 752  * allocated in the bitmap buffer's "last committed data" copy.  This
 753  * prevents deletes from freeing up the page for reuse until we have
 754  * committed the delete transaction.
 755  *
 756  * If we didn't do this, then deleting something and reallocating it as
 757  * data would allow the old block to be overwritten before the
 758  * transaction committed (because we force data to disk before commit).
 759  * This would lead to corruption if we crashed between overwriting the
 760  * data and committing the delete.
 761  *
 762  * @@@ We may want to make this allocation behaviour conditional on
 763  * data-writes at some point, and disable it for metadata allocations or
 764  * sync-data inodes."
 765  *
 766  * Note: OCFS2 already does this differently for metadata vs data
 767  * allocations, as those bitmaps are separate and undo access is never
 768  * called on a metadata group descriptor.
 769  */
 770 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
 771                                          int nr)
 772 {
 773         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 774
 775         if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
 776                 return 0;
 777         if (!buffer_jbd(bg_bh) || !bh2jh(bg_bh)->b_committed_data)
 778                 return 1;
 779
 780         bg = (struct ocfs2_group_desc *) bh2jh(bg_bh)->b_committed_data;
 781         return !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
 782 }
 783
 784 static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
 785                                              struct buffer_head *bg_bh,
 786                                              unsigned int bits_wanted,
 787                                              unsigned int total_bits,
 788                                              u16 *bit_off,
 789                                              u16 *bits_found)
 790 {
 791         void *bitmap;
 792         u16 best_offset, best_size;
 793         int offset, start, found, status = 0;
 794         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 795
 796         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
 797                 OCFS2_RO_ON_INVALID_GROUP_DESC(osb->sb, bg);
 798                 return -EIO;
 799         }
 800
 801         found = start = best_offset = best_size = 0;
 802         bitmap = bg->bg_bitmap;
 803
 804         while((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) != -1) {
 805                 if (offset == total_bits)
 806                         break;
 807
 808                 if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
 809                         /* We found a zero, but we can't use it as it
 810                          * hasn't been put to disk yet! */
 811                         found = 0;
 812                         start = offset + 1;
 813                 } else if (offset == start) {
 814                         /* we found a zero */
 815                         found++;
 816                         /* move start to the next bit to test */
 817                         start++;
 818                 } else {
 819                         /* got a zero after some ones */
 820                         found = 1;
 821                         start = offset + 1;
 822                 }
 823                 if (found > best_size) {
 824                         best_size = found;
 825                         best_offset = start - found;
 826                 }
 827                 /* we got everything we needed */
 828                 if (found == bits_wanted) {
 829                         /* mlog(0, "Found it all!\n"); */
 830                         break;
 831                 }
 832         }
 833
 834         /* XXX: I think the first clause is equivalent to the second
 835          *      - jlbec */
 836         if (found == bits_wanted) {
 837                 *bit_off = start - found;
 838                 *bits_found = found;
 839         } else if (best_size) {
 840                 *bit_off = best_offset;
 841                 *bits_found = best_size;
 842         } else {
 843                 status = -ENOSPC;
 844                 /* No error log here -- see the comment above
 845                  * ocfs2_test_bg_bit_allocatable */
 846         }
 847
 848         return status;
 849 }
 850
 851 static inline int ocfs2_block_group_set_bits(handle_t *handle,
 852                                              struct inode *alloc_inode,
 853                                              struct ocfs2_group_desc *bg,
 854                                              struct buffer_head *group_bh,
 855                                              unsigned int bit_off,
 856                                              unsigned int num_bits)
 857 {
 858         int status;
 859         void *bitmap = bg->bg_bitmap;
 860         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
 861
 862         mlog_entry_void();
 863
 864         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
 865                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
 866                 status = -EIO;
 867                 goto bail;
 868         }
 869         BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
 870
 871         mlog(0, "block_group_set_bits: off = %u, num = %u\n", bit_off,
 872              num_bits);
 873
 874         if (ocfs2_is_cluster_bitmap(alloc_inode))
 875                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
 876
 877         status = ocfs2_journal_access(handle,
 878                                       alloc_inode,
 879                                       group_bh,
 880                                       journal_type);
 881         if (status < 0) {
 882                 mlog_errno(status);
 883                 goto bail;
 884         }
 885
 886         le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
 887
 888         while(num_bits--)
 889                 ocfs2_set_bit(bit_off++, bitmap);
 890
 891         status = ocfs2_journal_dirty(handle,
 892                                      group_bh);
 893         if (status < 0) {
 894                 mlog_errno(status);
 895                 goto bail;
 896         }
 897
 898 bail:
 899         mlog_exit(status);
 900         return status;
 901 }
 902
 903 /* find the one with the most empty bits */
 904 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
 905 {
 906         u16 curr, best;
 907
 908         BUG_ON(!cl->cl_next_free_rec);
 909
 910         best = curr = 0;
 911         while (curr < le16_to_cpu(cl->cl_next_free_rec)) {
 912                 if (le32_to_cpu(cl->cl_recs[curr].c_free) >
 913                     le32_to_cpu(cl->cl_recs[best].c_free))
 914                         best = curr;
 915                 curr++;
 916         }
 917
 918         BUG_ON(best >= le16_to_cpu(cl->cl_next_free_rec));
 919         return best;
 920 }
 921
 922 static int ocfs2_relink_block_group(handle_t *handle,
 923                                     struct inode *alloc_inode,
 924                                     struct buffer_head *fe_bh,
 925                                     struct buffer_head *bg_bh,
 926                                     struct buffer_head *prev_bg_bh,
 927                                     u16 chain)
 928 {
 929         int status;
 930         /* there is a really tiny chance the journal calls could fail,
 931          * but we wouldn't want inconsistent blocks in *any* case. */
 932         u64 fe_ptr, bg_ptr, prev_bg_ptr;
 933         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
 934         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 935         struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
 936
 937         if (!OCFS2_IS_VALID_DINODE(fe)) {
 938                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
 939                 status = -EIO;
 940                 goto out;
 941         }
 942         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
 943                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
 944                 status = -EIO;
 945                 goto out;
 946         }
 947         if (!OCFS2_IS_VALID_GROUP_DESC(prev_bg)) {
 948                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, prev_bg);
 949                 status = -EIO;
 950                 goto out;
 951         }
 952
 953         mlog(0, "Suballoc %llu, chain %u, move group %llu to top, prev = %llu\n",
 954              (unsigned long long)le64_to_cpu(fe->i_blkno), chain,
 955              (unsigned long long)le64_to_cpu(bg->bg_blkno),
 956              (unsigned long long)le64_to_cpu(prev_bg->bg_blkno));
 957
 958         fe_ptr = le64_to_cpu(fe->id2.i_chain.cl_recs[chain].c_blkno);
 959         bg_ptr = le64_to_cpu(bg->bg_next_group);
 960         prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
 961
 962         status = ocfs2_journal_access(handle, alloc_inode, prev_bg_bh,
 963                                       OCFS2_JOURNAL_ACCESS_WRITE);
 964         if (status < 0) {
 965                 mlog_errno(status);
 966                 goto out_rollback;
 967         }
 968
 969         prev_bg->bg_next_group = bg->bg_next_group;
 970
 971         status = ocfs2_journal_dirty(handle, prev_bg_bh);
 972         if (status < 0) {
 973                 mlog_errno(status);
 974                 goto out_rollback;
 975         }
 976
 977         status = ocfs2_journal_access(handle, alloc_inode, bg_bh,
 978                                       OCFS2_JOURNAL_ACCESS_WRITE);
 979         if (status < 0) {
 980                 mlog_errno(status);
 981                 goto out_rollback;
 982         }
 983
 984         bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
 985
 986         status = ocfs2_journal_dirty(handle, bg_bh);
 987         if (status < 0) {
 988                 mlog_errno(status);
 989                 goto out_rollback;
 990         }
 991
 992         status = ocfs2_journal_access(handle, alloc_inode, fe_bh,
 993                                       OCFS2_JOURNAL_ACCESS_WRITE);
 994         if (status < 0) {
 995                 mlog_errno(status);
 996                 goto out_rollback;
 997         }
 998
 999         fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
1000
1001         status = ocfs2_journal_dirty(handle, fe_bh);
1002         if (status < 0) {
1003                 mlog_errno(status);
1004                 goto out_rollback;
1005         }
1006
1007         status = 0;
1008 out_rollback:
1009         if (status < 0) {
1010                 fe->id2.i_chain.cl_recs[chain].c_blkno = cpu_to_le64(fe_ptr);
1011                 bg->bg_next_group = cpu_to_le64(bg_ptr);
1012                 prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
1013         }
1014 out:
1015         mlog_exit(status);
1016         return status;
1017 }
1018
1019 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
1020                                                      u32 wanted)
1021 {
1022         return le16_to_cpu(bg->bg_free_bits_count) > wanted;
1023 }
1024
1025 /* return 0 on success, -ENOSPC to keep searching and any other < 0
1026  * value on error. */
1027 static int ocfs2_cluster_group_search(struct inode *inode,
1028                                       struct buffer_head *group_bh,
1029                                       u32 bits_wanted, u32 min_bits,
1030                                       u64 max_block,
1031                                       u16 *bit_off, u16 *bits_found)
1032 {
1033         int search = -ENOSPC;
1034         int ret;
1035         u64 blkoff;
1036         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
1037         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1038         u16 tmp_off, tmp_found;
1039         unsigned int max_bits, gd_cluster_off;
1040
1041         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1042
1043         if (gd->bg_free_bits_count) {
1044                 max_bits = le16_to_cpu(gd->bg_bits);
1045
1046                 /* Tail groups in cluster bitmaps which aren't cpg
1047                  * aligned are prone to partial extention by a failed
1048                  * fs resize. If the file system resize never got to
1049                  * update the dinode cluster count, then we don't want
1050                  * to trust any clusters past it, regardless of what
1051                  * the group descriptor says. */
1052                 gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
1053                                                           le64_to_cpu(gd->bg_blkno));
1054                 if ((gd_cluster_off + max_bits) >
1055                     OCFS2_I(inode)->ip_clusters) {
1056                         max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
1057                         mlog(0, "Desc %llu, bg_bits %u, clusters %u, use %u\n",
1058                              (unsigned long long)le64_to_cpu(gd->bg_blkno),
1059                              le16_to_cpu(gd->bg_bits),
1060                              OCFS2_I(inode)->ip_clusters, max_bits);
1061                 }
1062
1063                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1064                                                         group_bh, bits_wanted,
1065                                                         max_bits,
1066                                                         &tmp_off, &tmp_found);
1067                 if (ret)
1068                         return ret;
1069
1070                 if (max_block) {
1071                         blkoff = ocfs2_clusters_to_blocks(inode->i_sb,
1072                                                           gd_cluster_off +
1073                                                           tmp_off + tmp_found);
1074                         mlog(0, "Checking %llu against %llu\n",
1075                              (unsigned long long)blkoff,
1076                              (unsigned long long)max_block);
1077                         if (blkoff > max_block)
1078                                 return -ENOSPC;
1079                 }
1080
1081                 /* ocfs2_block_group_find_clear_bits() might
1082                  * return success, but we still want to return
1083                  * -ENOSPC unless it found the minimum number
1084                  * of bits. */
1085                 if (min_bits <= tmp_found) {
1086                         *bit_off = tmp_off;
1087                         *bits_found = tmp_found;
1088                         search = 0; /* success */
1089                 } else if (tmp_found) {
1090                         /*
1091                          * Don't show bits which we'll be returning
1092                          * for allocation to the local alloc bitmap.
1093                          */
1094                         ocfs2_local_alloc_seen_free_bits(osb, tmp_found);
1095                 }
1096         }
1097
1098         return search;
1099 }
1100
1101 static int ocfs2_block_group_search(struct inode *inode,
1102                                     struct buffer_head *group_bh,
1103                                     u32 bits_wanted, u32 min_bits,
1104                                     u64 max_block,
1105                                     u16 *bit_off, u16 *bits_found)
1106 {
1107         int ret = -ENOSPC;
1108         u64 blkoff;
1109         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
1110
1111         BUG_ON(min_bits != 1);
1112         BUG_ON(ocfs2_is_cluster_bitmap(inode));
1113
1114         if (bg->bg_free_bits_count) {
1115                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1116                                                         group_bh, bits_wanted,
1117                                                         le16_to_cpu(bg->bg_bits),
1118                                                         bit_off, bits_found);
1119                 if (!ret && max_block) {
1120                         blkoff = le64_to_cpu(bg->bg_blkno) + *bit_off +
1121                                 *bits_found;
1122                         mlog(0, "Checking %llu against %llu\n",
1123                              (unsigned long long)blkoff,
1124                              (unsigned long long)max_block);
1125                         if (blkoff > max_block)
1126                                 ret = -ENOSPC;
1127                 }
1128         }
1129
1130         return ret;
1131 }
1132
1133 static int ocfs2_alloc_dinode_update_counts(struct inode *inode,
1134                                        handle_t *handle,
1135                                        struct buffer_head *di_bh,
1136                                        u32 num_bits,
1137                                        u16 chain)
1138 {
1139         int ret;
1140         u32 tmp_used;
1141         struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1142         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &di->id2.i_chain;
1143
1144         ret = ocfs2_journal_access(handle, inode, di_bh,
1145                                    OCFS2_JOURNAL_ACCESS_WRITE);
1146         if (ret < 0) {
1147                 mlog_errno(ret);
1148                 goto out;
1149         }
1150
1151         tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1152         di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
1153         le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
1154
1155         ret = ocfs2_journal_dirty(handle, di_bh);
1156         if (ret < 0)
1157                 mlog_errno(ret);
1158
1159 out:
1160         return ret;
1161 }
1162
1163 static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
1164                                   handle_t *handle,
1165                                   u32 bits_wanted,
1166                                   u32 min_bits,
1167                                   u16 *bit_off,
1168                                   unsigned int *num_bits,
1169                                   u64 gd_blkno,
1170                                   u16 *bits_left)
1171 {
1172         int ret;
1173         u16 found;
1174         struct buffer_head *group_bh = NULL;
1175         struct ocfs2_group_desc *gd;
1176         struct inode *alloc_inode = ac->ac_inode;
1177
1178         ret = ocfs2_read_block(OCFS2_SB(alloc_inode->i_sb), gd_blkno,
1179                                &group_bh, OCFS2_BH_CACHED, alloc_inode);
1180         if (ret < 0) {
1181                 mlog_errno(ret);
1182                 return ret;
1183         }
1184
1185         gd = (struct ocfs2_group_desc *) group_bh->b_data;
1186         if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
1187                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, gd);
1188                 ret = -EIO;
1189                 goto out;
1190         }
1191
1192         ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
1193                                   ac->ac_max_block, bit_off, &found);
1194         if (ret < 0) {
1195                 if (ret != -ENOSPC)
1196                         mlog_errno(ret);
1197                 goto out;
1198         }
1199
1200         *num_bits = found;
1201
1202         ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
1203                                                *num_bits,
1204                                                le16_to_cpu(gd->bg_chain));
1205         if (ret < 0) {
1206                 mlog_errno(ret);
1207                 goto out;
1208         }
1209
1210         ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
1211                                          *bit_off, *num_bits);
1212         if (ret < 0)
1213                 mlog_errno(ret);
1214
1215         *bits_left = le16_to_cpu(gd->bg_free_bits_count);
1216
1217 out:
1218         brelse(group_bh);
1219
1220         return ret;
1221 }
1222
1223 static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
1224                               handle_t *handle,
1225                               u32 bits_wanted,
1226                               u32 min_bits,
1227                               u16 *bit_off,
1228                               unsigned int *num_bits,
1229                               u64 *bg_blkno,
1230                               u16 *bits_left)
1231 {
1232         int status;
1233         u16 chain, tmp_bits;
1234         u32 tmp_used;
1235         u64 next_group;
1236         struct inode *alloc_inode = ac->ac_inode;
1237         struct buffer_head *group_bh = NULL;
1238         struct buffer_head *prev_group_bh = NULL;
1239         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1240         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1241         struct ocfs2_group_desc *bg;
1242
1243         chain = ac->ac_chain;
1244         mlog(0, "trying to alloc %u bits from chain %u, inode %llu\n",
1245              bits_wanted, chain,
1246              (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno);
1247
1248         status = ocfs2_read_block(OCFS2_SB(alloc_inode->i_sb),
1249                                   le64_to_cpu(cl->cl_recs[chain].c_blkno),
1250                                   &group_bh, OCFS2_BH_CACHED, alloc_inode);
1251         if (status < 0) {
1252                 mlog_errno(status);
1253                 goto bail;
1254         }
1255         bg = (struct ocfs2_group_desc *) group_bh->b_data;
1256         status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, bg);
1257         if (status) {
1258                 mlog_errno(status);
1259                 goto bail;
1260         }
1261
1262         status = -ENOSPC;
1263         /* for now, the chain search is a bit simplistic. We just use
1264          * the 1st group with any empty bits. */
1265         while ((status = ac->ac_group_search(alloc_inode, group_bh,
1266                                              bits_wanted, min_bits,
1267                                              ac->ac_max_block, bit_off,
1268                                              &tmp_bits)) == -ENOSPC) {
1269                 if (!bg->bg_next_group)
1270                         break;
1271                 if (prev_group_bh) {
1272                         brelse(prev_group_bh);
1273                         prev_group_bh = NULL;
1274                 }
1275                 next_group = le64_to_cpu(bg->bg_next_group);
1276                 prev_group_bh = group_bh;
1277                 group_bh = NULL;
1278                 status = ocfs2_read_block(OCFS2_SB(alloc_inode->i_sb),
1279                                           next_group, &group_bh,
1280                                           OCFS2_BH_CACHED, alloc_inode);
1281                 if (status < 0) {
1282                         mlog_errno(status);
1283                         goto bail;
1284                 }
1285                 bg = (struct ocfs2_group_desc *) group_bh->b_data;
1286                 status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, bg);
1287                 if (status) {
1288                         mlog_errno(status);
1289                         goto bail;
1290                 }
1291         }
1292         if (status < 0) {
1293                 if (status != -ENOSPC)
1294                         mlog_errno(status);
1295                 goto bail;
1296         }
1297
1298         mlog(0, "alloc succeeds: we give %u bits from block group %llu\n",
1299              tmp_bits, (unsigned long long)le64_to_cpu(bg->bg_blkno));
1300
1301         *num_bits = tmp_bits;
1302
1303         BUG_ON(*num_bits == 0);
1304
1305         /*
1306          * Keep track of previous block descriptor read. When
1307          * we find a target, if we have read more than X
1308          * number of descriptors, and the target is reasonably
1309          * empty, relink him to top of his chain.
1310          *
1311          * We've read 0 extra blocks and only send one more to
1312          * the transaction, yet the next guy to search has a
1313          * much easier time.
1314          *
1315          * Do this *after* figuring out how many bits we're taking out
1316          * of our target group.
1317          */
1318         if (ac->ac_allow_chain_relink &&
1319             (prev_group_bh) &&
1320             (ocfs2_block_group_reasonably_empty(bg, *num_bits))) {
1321                 status = ocfs2_relink_block_group(handle, alloc_inode,
1322                                                   ac->ac_bh, group_bh,
1323                                                   prev_group_bh, chain);
1324                 if (status < 0) {
1325                         mlog_errno(status);
1326                         goto bail;
1327                 }
1328         }
1329
1330         /* Ok, claim our bits now: set the info on dinode, chainlist
1331          * and then the group */
1332         status = ocfs2_journal_access(handle,
1333                                       alloc_inode,
1334                                       ac->ac_bh,
1335                                       OCFS2_JOURNAL_ACCESS_WRITE);
1336         if (status < 0) {
1337                 mlog_errno(status);
1338                 goto bail;
1339         }
1340
1341         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
1342         fe->id1.bitmap1.i_used = cpu_to_le32(*num_bits + tmp_used);
1343         le32_add_cpu(&cl->cl_recs[chain].c_free, -(*num_bits));
1344
1345         status = ocfs2_journal_dirty(handle,
1346                                      ac->ac_bh);
1347         if (status < 0) {
1348                 mlog_errno(status);
1349                 goto bail;
1350         }
1351
1352         status = ocfs2_block_group_set_bits(handle,
1353                                             alloc_inode,
1354                                             bg,
1355                                             group_bh,
1356                                             *bit_off,
1357                                             *num_bits);
1358         if (status < 0) {
1359                 mlog_errno(status);
1360                 goto bail;
1361         }
1362
1363         mlog(0, "Allocated %u bits from suballocator %llu\n", *num_bits,
1364              (unsigned long long)le64_to_cpu(fe->i_blkno));
1365
1366         *bg_blkno = le64_to_cpu(bg->bg_blkno);
1367         *bits_left = le16_to_cpu(bg->bg_free_bits_count);
1368 bail:
1369         if (group_bh)
1370                 brelse(group_bh);
1371         if (prev_group_bh)
1372                 brelse(prev_group_bh);
1373
1374         mlog_exit(status);
1375         return status;
1376 }
1377
1378 /* will give out up to bits_wanted contiguous bits. */
1379 static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
1380                                      struct ocfs2_alloc_context *ac,
1381                                      handle_t *handle,
1382                                      u32 bits_wanted,
1383                                      u32 min_bits,
1384                                      u16 *bit_off,
1385                                      unsigned int *num_bits,
1386                                      u64 *bg_blkno)
1387 {
1388         int status;
1389         u16 victim, i;
1390         u16 bits_left = 0;
1391         u64 hint_blkno = ac->ac_last_group;
1392         struct ocfs2_chain_list *cl;
1393         struct ocfs2_dinode *fe;
1394
1395         mlog_entry_void();
1396
1397         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1398         BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1399         BUG_ON(!ac->ac_bh);
1400
1401         fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1402         if (!OCFS2_IS_VALID_DINODE(fe)) {
1403                 OCFS2_RO_ON_INVALID_DINODE(osb->sb, fe);
1404                 status = -EIO;
1405                 goto bail;
1406         }
1407         if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1408             le32_to_cpu(fe->id1.bitmap1.i_total)) {
1409                 ocfs2_error(osb->sb, "Chain allocator dinode %llu has %u used "
1410                             "bits but only %u total.",
1411                             (unsigned long long)le64_to_cpu(fe->i_blkno),
1412                             le32_to_cpu(fe->id1.bitmap1.i_used),
1413                             le32_to_cpu(fe->id1.bitmap1.i_total));
1414                 status = -EIO;
1415                 goto bail;
1416         }
1417
1418         if (hint_blkno) {
1419                 /* Attempt to short-circuit the usual search mechanism
1420                  * by jumping straight to the most recently used
1421                  * allocation group. This helps us mantain some
1422                  * contiguousness across allocations. */
1423                 status = ocfs2_search_one_group(ac, handle, bits_wanted,
1424                                                 min_bits, bit_off, num_bits,
1425                                                 hint_blkno, &bits_left);
1426                 if (!status) {
1427                         /* Be careful to update *bg_blkno here as the
1428                          * caller is expecting it to be filled in, and
1429                          * ocfs2_search_one_group() won't do that for
1430                          * us. */
1431                         *bg_blkno = hint_blkno;
1432                         goto set_hint;
1433                 }
1434                 if (status < 0 && status != -ENOSPC) {
1435                         mlog_errno(status);
1436                         goto bail;
1437                 }
1438         }
1439
1440         cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1441
1442         victim = ocfs2_find_victim_chain(cl);
1443         ac->ac_chain = victim;
1444         ac->ac_allow_chain_relink = 1;
1445
1446         status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits, bit_off,
1447                                     num_bits, bg_blkno, &bits_left);
1448         if (!status)
1449                 goto set_hint;
1450         if (status < 0 && status != -ENOSPC) {
1451                 mlog_errno(status);
1452                 goto bail;
1453         }
1454
1455         mlog(0, "Search of victim chain %u came up with nothing, "
1456              "trying all chains now.\n", victim);
1457
1458         /* If we didn't pick a good victim, then just default to
1459          * searching each chain in order. Don't allow chain relinking
1460          * because we only calculate enough journal credits for one
1461          * relink per alloc. */
1462         ac->ac_allow_chain_relink = 0;
1463         for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
1464                 if (i == victim)
1465                         continue;
1466                 if (!cl->cl_recs[i].c_free)
1467                         continue;
1468
1469                 ac->ac_chain = i;
1470                 status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1471                                             bit_off, num_bits, bg_blkno,
1472                                             &bits_left);
1473                 if (!status)
1474                         break;
1475                 if (status < 0 && status != -ENOSPC) {
1476                         mlog_errno(status);
1477                         goto bail;
1478                 }
1479         }
1480
1481 set_hint:
1482         if (status != -ENOSPC) {
1483                 /* If the next search of this group is not likely to
1484                  * yield a suitable extent, then we reset the last
1485                  * group hint so as to not waste a disk read */
1486                 if (bits_left < min_bits)
1487                         ac->ac_last_group = 0;
1488                 else
1489                         ac->ac_last_group = *bg_blkno;
1490         }
1491
1492 bail:
1493         mlog_exit(status);
1494         return status;
1495 }
1496
1497 int ocfs2_claim_metadata(struct ocfs2_super *osb,
1498                          handle_t *handle,
1499                          struct ocfs2_alloc_context *ac,
1500                          u32 bits_wanted,
1501                          u16 *suballoc_bit_start,
1502                          unsigned int *num_bits,
1503                          u64 *blkno_start)
1504 {
1505         int status;
1506         u64 bg_blkno;
1507
1508         BUG_ON(!ac);
1509         BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
1510         BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
1511
1512         status = ocfs2_claim_suballoc_bits(osb,
1513                                            ac,
1514                                            handle,
1515                                            bits_wanted,
1516                                            1,
1517                                            suballoc_bit_start,
1518                                            num_bits,
1519                                            &bg_blkno);
1520         if (status < 0) {
1521                 mlog_errno(status);
1522                 goto bail;
1523         }
1524         atomic_inc(&osb->alloc_stats.bg_allocs);
1525
1526         *blkno_start = bg_blkno + (u64) *suballoc_bit_start;
1527         ac->ac_bits_given += (*num_bits);
1528         status = 0;
1529 bail:
1530         mlog_exit(status);
1531         return status;
1532 }
1533
1534 int ocfs2_claim_new_inode(struct ocfs2_super *osb,
1535                           handle_t *handle,
1536                           struct ocfs2_alloc_context *ac,
1537                           u16 *suballoc_bit,
1538                           u64 *fe_blkno)
1539 {
1540         int status;
1541         unsigned int num_bits;
1542         u64 bg_blkno;
1543
1544         mlog_entry_void();
1545
1546         BUG_ON(!ac);
1547         BUG_ON(ac->ac_bits_given != 0);
1548         BUG_ON(ac->ac_bits_wanted != 1);
1549         BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
1550
1551         status = ocfs2_claim_suballoc_bits(osb,
1552                                            ac,
1553                                            handle,
1554                                            1,
1555                                            1,
1556                                            suballoc_bit,
1557                                            &num_bits,
1558                                            &bg_blkno);
1559         if (status < 0) {
1560                 mlog_errno(status);
1561                 goto bail;
1562         }
1563         atomic_inc(&osb->alloc_stats.bg_allocs);
1564
1565         BUG_ON(num_bits != 1);
1566
1567         *fe_blkno = bg_blkno + (u64) (*suballoc_bit);
1568         ac->ac_bits_given++;
1569         status = 0;
1570 bail:
1571         mlog_exit(status);
1572         return status;
1573 }
1574
1575 /* translate a group desc. blkno and it's bitmap offset into
1576  * disk cluster offset. */
1577 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
1578                                                    u64 bg_blkno,
1579                                                    u16 bg_bit_off)
1580 {
1581         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1582         u32 cluster = 0;
1583
1584         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1585
1586         if (bg_blkno != osb->first_cluster_group_blkno)
1587                 cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
1588         cluster += (u32) bg_bit_off;
1589         return cluster;
1590 }
1591
1592 /* given a cluster offset, calculate which block group it belongs to
1593  * and return that block offset. */
1594 u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster)
1595 {
1596         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1597         u32 group_no;
1598
1599         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1600
1601         group_no = cluster / osb->bitmap_cpg;
1602         if (!group_no)
1603                 return osb->first_cluster_group_blkno;
1604         return ocfs2_clusters_to_blocks(inode->i_sb,
1605                                         group_no * osb->bitmap_cpg);
1606 }
1607
1608 /* given the block number of a cluster start, calculate which cluster
1609  * group and descriptor bitmap offset that corresponds to. */
1610 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
1611                                                 u64 data_blkno,
1612                                                 u64 *bg_blkno,
1613                                                 u16 *bg_bit_off)
1614 {
1615         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1616         u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
1617
1618         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1619
1620         *bg_blkno = ocfs2_which_cluster_group(inode,
1621                                               data_cluster);
1622
1623         if (*bg_blkno == osb->first_cluster_group_blkno)
1624                 *bg_bit_off = (u16) data_cluster;
1625         else
1626                 *bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
1627                                                              data_blkno - *bg_blkno);
1628 }
1629
1630 /*
1631  * min_bits - minimum contiguous chunk from this total allocation we
1632  * can handle. set to what we asked for originally for a full
1633  * contig. allocation, set to '1' to indicate we can deal with extents
1634  * of any size.
1635  */
1636 int __ocfs2_claim_clusters(struct ocfs2_super *osb,
1637                            handle_t *handle,
1638                            struct ocfs2_alloc_context *ac,
1639                            u32 min_clusters,
1640                            u32 max_clusters,
1641                            u32 *cluster_start,
1642                            u32 *num_clusters)
1643 {
1644         int status;
1645         unsigned int bits_wanted = max_clusters;
1646         u64 bg_blkno = 0;
1647         u16 bg_bit_off;
1648
1649         mlog_entry_void();
1650
1651         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1652
1653         BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
1654                && ac->ac_which != OCFS2_AC_USE_MAIN);
1655
1656         if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
1657                 status = ocfs2_claim_local_alloc_bits(osb,
1658                                                       handle,
1659                                                       ac,
1660                                                       bits_wanted,
1661                                                       cluster_start,
1662                                                       num_clusters);
1663                 if (!status)
1664                         atomic_inc(&osb->alloc_stats.local_data);
1665         } else {
1666                 if (min_clusters > (osb->bitmap_cpg - 1)) {
1667                         /* The only paths asking for contiguousness
1668                          * should know about this already. */
1669                         mlog(ML_ERROR, "minimum allocation requested %u exceeds "
1670                              "group bitmap size %u!\n", min_clusters,
1671                              osb->bitmap_cpg);
1672                         status = -ENOSPC;
1673                         goto bail;
1674                 }
1675                 /* clamp the current request down to a realistic size. */
1676                 if (bits_wanted > (osb->bitmap_cpg - 1))
1677                         bits_wanted = osb->bitmap_cpg - 1;
1678
1679                 status = ocfs2_claim_suballoc_bits(osb,
1680                                                    ac,
1681                                                    handle,
1682                                                    bits_wanted,
1683                                                    min_clusters,
1684                                                    &bg_bit_off,
1685                                                    num_clusters,
1686                                                    &bg_blkno);
1687                 if (!status) {
1688                         *cluster_start =
1689                                 ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
1690                                                                  bg_blkno,
1691                                                                  bg_bit_off);
1692                         atomic_inc(&osb->alloc_stats.bitmap_data);
1693                 }
1694         }
1695         if (status < 0) {
1696                 if (status != -ENOSPC)
1697                         mlog_errno(status);
1698                 goto bail;
1699         }
1700
1701         ac->ac_bits_given += *num_clusters;
1702
1703 bail:
1704         mlog_exit(status);
1705         return status;
1706 }
1707
1708 int ocfs2_claim_clusters(struct ocfs2_super *osb,
1709                          handle_t *handle,
1710                          struct ocfs2_alloc_context *ac,
1711                          u32 min_clusters,
1712                          u32 *cluster_start,
1713                          u32 *num_clusters)
1714 {
1715         unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
1716
1717         return __ocfs2_claim_clusters(osb, handle, ac, min_clusters,
1718                                       bits_wanted, cluster_start, num_clusters);
1719 }
1720
1721 static inline int ocfs2_block_group_clear_bits(handle_t *handle,
1722                                                struct inode *alloc_inode,
1723                                                struct ocfs2_group_desc *bg,
1724                                                struct buffer_head *group_bh,
1725                                                unsigned int bit_off,
1726                                                unsigned int num_bits)
1727 {
1728         int status;
1729         unsigned int tmp;
1730         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1731         struct ocfs2_group_desc *undo_bg = NULL;
1732
1733         mlog_entry_void();
1734
1735         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
1736                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
1737                 status = -EIO;
1738                 goto bail;
1739         }
1740
1741         mlog(0, "off = %u, num = %u\n", bit_off, num_bits);
1742
1743         if (ocfs2_is_cluster_bitmap(alloc_inode))
1744                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1745
1746         status = ocfs2_journal_access(handle, alloc_inode, group_bh,
1747                                       journal_type);
1748         if (status < 0) {
1749                 mlog_errno(status);
1750                 goto bail;
1751         }
1752
1753         if (ocfs2_is_cluster_bitmap(alloc_inode))
1754                 undo_bg = (struct ocfs2_group_desc *) bh2jh(group_bh)->b_committed_data;
1755
1756         tmp = num_bits;
1757         while(tmp--) {
1758                 ocfs2_clear_bit((bit_off + tmp),
1759                                 (unsigned long *) bg->bg_bitmap);
1760                 if (ocfs2_is_cluster_bitmap(alloc_inode))
1761                         ocfs2_set_bit(bit_off + tmp,
1762                                       (unsigned long *) undo_bg->bg_bitmap);
1763         }
1764         le16_add_cpu(&bg->bg_free_bits_count, num_bits);
1765
1766         status = ocfs2_journal_dirty(handle, group_bh);
1767         if (status < 0)
1768                 mlog_errno(status);
1769 bail:
1770         return status;
1771 }
1772
1773 /*
1774  * expects the suballoc inode to already be locked.
1775  */
1776 int ocfs2_free_suballoc_bits(handle_t *handle,
1777                              struct inode *alloc_inode,
1778                              struct buffer_head *alloc_bh,
1779                              unsigned int start_bit,
1780                              u64 bg_blkno,
1781                              unsigned int count)
1782 {
1783         int status = 0;
1784         u32 tmp_used;
1785         struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
1786         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
1787         struct ocfs2_chain_list *cl = &fe->id2.i_chain;
1788         struct buffer_head *group_bh = NULL;
1789         struct ocfs2_group_desc *group;
1790
1791         mlog_entry_void();
1792
1793         if (!OCFS2_IS_VALID_DINODE(fe)) {
1794                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
1795                 status = -EIO;
1796                 goto bail;
1797         }
1798         BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
1799
1800         mlog(0, "%llu: freeing %u bits from group %llu, starting at %u\n",
1801              (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno, count,
1802              (unsigned long long)bg_blkno, start_bit);
1803
1804         status = ocfs2_read_block(osb, bg_blkno, &group_bh, OCFS2_BH_CACHED,
1805                                   alloc_inode);
1806         if (status < 0) {
1807                 mlog_errno(status);
1808                 goto bail;
1809         }
1810
1811         group = (struct ocfs2_group_desc *) group_bh->b_data;
1812         status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, group);
1813         if (status) {
1814                 mlog_errno(status);
1815                 goto bail;
1816         }
1817         BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
1818
1819         status = ocfs2_block_group_clear_bits(handle, alloc_inode,
1820                                               group, group_bh,
1821                                               start_bit, count);
1822         if (status < 0) {
1823                 mlog_errno(status);
1824                 goto bail;
1825         }
1826
1827         status = ocfs2_journal_access(handle, alloc_inode, alloc_bh,
1828                                       OCFS2_JOURNAL_ACCESS_WRITE);
1829         if (status < 0) {
1830                 mlog_errno(status);
1831                 goto bail;
1832         }
1833
1834         le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
1835                      count);
1836         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
1837         fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
1838
1839         status = ocfs2_journal_dirty(handle, alloc_bh);
1840         if (status < 0) {
1841                 mlog_errno(status);
1842                 goto bail;
1843         }
1844
1845 bail:
1846         if (group_bh)
1847                 brelse(group_bh);
1848
1849         mlog_exit(status);
1850         return status;
1851 }
1852
1853 int ocfs2_free_dinode(handle_t *handle,
1854                       struct inode *inode_alloc_inode,
1855                       struct buffer_head *inode_alloc_bh,
1856                       struct ocfs2_dinode *di)
1857 {
1858         u64 blk = le64_to_cpu(di->i_blkno);
1859         u16 bit = le16_to_cpu(di->i_suballoc_bit);
1860         u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
1861
1862         return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
1863                                         inode_alloc_bh, bit, bg_blkno, 1);
1864 }
1865
1866 int ocfs2_free_clusters(handle_t *handle,
1867                        struct inode *bitmap_inode,
1868                        struct buffer_head *bitmap_bh,
1869                        u64 start_blk,
1870                        unsigned int num_clusters)
1871 {
1872         int status;
1873         u16 bg_start_bit;
1874         u64 bg_blkno;
1875         struct ocfs2_dinode *fe;
1876
1877         /* You can't ever have a contiguous set of clusters
1878          * bigger than a block group bitmap so we never have to worry
1879          * about looping on them. */
1880
1881         mlog_entry_void();
1882
1883         /* This is expensive. We can safely remove once this stuff has
1884          * gotten tested really well. */
1885         BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb, ocfs2_blocks_to_clusters(bitmap_inode->i_sb, start_blk)));
1886
1887         fe = (struct ocfs2_dinode *) bitmap_bh->b_data;
1888
1889         ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
1890                                      &bg_start_bit);
1891
1892         mlog(0, "want to free %u clusters starting at block %llu\n",
1893              num_clusters, (unsigned long long)start_blk);
1894         mlog(0, "bg_blkno = %llu, bg_start_bit = %u\n",
1895              (unsigned long long)bg_blkno, bg_start_bit);
1896
1897         status = ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
1898                                           bg_start_bit, bg_blkno,
1899                                           num_clusters);
1900         if (status < 0) {
1901                 mlog_errno(status);
1902                 goto out;
1903         }
1904
1905         ocfs2_local_alloc_seen_free_bits(OCFS2_SB(bitmap_inode->i_sb),
1906                                          num_clusters);
1907
1908 out:
1909         mlog_exit(status);
1910         return status;
1911 }
1912
1913 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg)
1914 {
1915         printk("Block Group:\n");
1916         printk("bg_signature:       %s\n", bg->bg_signature);
1917         printk("bg_size:            %u\n", bg->bg_size);
1918         printk("bg_bits:            %u\n", bg->bg_bits);
1919         printk("bg_free_bits_count: %u\n", bg->bg_free_bits_count);
1920         printk("bg_chain:           %u\n", bg->bg_chain);
1921         printk("bg_generation:      %u\n", le32_to_cpu(bg->bg_generation));
1922         printk("bg_next_group:      %llu\n",
1923                (unsigned long long)bg->bg_next_group);
1924         printk("bg_parent_dinode:   %llu\n",
1925                (unsigned long long)bg->bg_parent_dinode);
1926         printk("bg_blkno:           %llu\n",
1927                (unsigned long long)bg->bg_blkno);
1928 }
1929
1930 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe)
1931 {
1932         int i;
1933
1934         printk("Suballoc Inode %llu:\n", (unsigned long long)fe->i_blkno);
1935         printk("i_signature:                  %s\n", fe->i_signature);
1936         printk("i_size:                       %llu\n",
1937                (unsigned long long)fe->i_size);
1938         printk("i_clusters:                   %u\n", fe->i_clusters);
1939         printk("i_generation:                 %u\n",
1940                le32_to_cpu(fe->i_generation));
1941         printk("id1.bitmap1.i_used:           %u\n",
1942                le32_to_cpu(fe->id1.bitmap1.i_used));
1943         printk("id1.bitmap1.i_total:          %u\n",
1944                le32_to_cpu(fe->id1.bitmap1.i_total));
1945         printk("id2.i_chain.cl_cpg:           %u\n", fe->id2.i_chain.cl_cpg);
1946         printk("id2.i_chain.cl_bpc:           %u\n", fe->id2.i_chain.cl_bpc);
1947         printk("id2.i_chain.cl_count:         %u\n", fe->id2.i_chain.cl_count);
1948         printk("id2.i_chain.cl_next_free_rec: %u\n",
1949                fe->id2.i_chain.cl_next_free_rec);
1950         for(i = 0; i < fe->id2.i_chain.cl_next_free_rec; i++) {
1951                 printk("fe->id2.i_chain.cl_recs[%d].c_free:  %u\n", i,
1952                        fe->id2.i_chain.cl_recs[i].c_free);
1953                 printk("fe->id2.i_chain.cl_recs[%d].c_total: %u\n", i,
1954                        fe->id2.i_chain.cl_recs[i].c_total);
1955                 printk("fe->id2.i_chain.cl_recs[%d].c_blkno: %llu\n", i,
1956                        (unsigned long long)fe->id2.i_chain.cl_recs[i].c_blkno);
1957         }
1958 }
1959
1960 /*
1961  * For a given allocation, determine which allocators will need to be
1962  * accessed, and lock them, reserving the appropriate number of bits.
1963  *
1964  * Sparse file systems call this from ocfs2_write_begin_nolock()
1965  * and ocfs2_allocate_unwritten_extents().
1966  *
1967  * File systems which don't support holes call this from
1968  * ocfs2_extend_allocation().
1969  */
1970 int ocfs2_lock_allocators(struct inode *inode,
1971                           struct ocfs2_extent_tree *et,
1972                           u32 clusters_to_add, u32 extents_to_split,
1973                           struct ocfs2_alloc_context **data_ac,
1974                           struct ocfs2_alloc_context **meta_ac)
1975 {
1976         int ret = 0, num_free_extents;
1977         unsigned int max_recs_needed = clusters_to_add + 2 * extents_to_split;
1978         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1979
1980         *meta_ac = NULL;
1981         if (data_ac)
1982                 *data_ac = NULL;
1983
1984         BUG_ON(clusters_to_add != 0 && data_ac == NULL);
1985
1986         num_free_extents = ocfs2_num_free_extents(osb, inode, et);
1987         if (num_free_extents < 0) {
1988                 ret = num_free_extents;
1989                 mlog_errno(ret);
1990                 goto out;
1991         }
1992
1993         /*
1994          * Sparse allocation file systems need to be more conservative
1995          * with reserving room for expansion - the actual allocation
1996          * happens while we've got a journal handle open so re-taking
1997          * a cluster lock (because we ran out of room for another
1998          * extent) will violate ordering rules.
1999          *
2000          * Most of the time we'll only be seeing this 1 cluster at a time
2001          * anyway.
2002          *
2003          * Always lock for any unwritten extents - we might want to
2004          * add blocks during a split.
2005          */
2006         if (!num_free_extents ||
2007             (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed)) {
2008                 ret = ocfs2_reserve_new_metadata(osb, et->et_root_el, meta_ac);
2009                 if (ret < 0) {
2010                         if (ret != -ENOSPC)
2011                                 mlog_errno(ret);
2012                         goto out;
2013                 }
2014         }
2015
2016         if (clusters_to_add == 0)
2017                 goto out;
2018
2019         ret = ocfs2_reserve_clusters(osb, clusters_to_add, data_ac);
2020         if (ret < 0) {
2021                 if (ret != -ENOSPC)
2022                         mlog_errno(ret);
2023                 goto out;
2024         }
2025
2026 out:
2027         if (ret) {
2028                 if (*meta_ac) {
2029                         ocfs2_free_alloc_context(*meta_ac);
2030                         *meta_ac = NULL;
2031                 }
2032
2033                 /*
2034                  * We cannot have an error and a non null *data_ac.
2035                  */
2036         }
2037
2038         return ret;
2039 }