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(struct ocfs2_journal_handle *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_reserve_suballoc_bits(struct ocfs2_super *osb,
  63                                        struct ocfs2_alloc_context *ac);
  64
  65 static int ocfs2_cluster_group_search(struct inode *inode,
  66                                       struct buffer_head *group_bh,
  67                                       u32 bits_wanted, u32 min_bits,
  68                                       u16 *bit_off, u16 *bits_found);
  69 static int ocfs2_block_group_search(struct inode *inode,
  70                                     struct buffer_head *group_bh,
  71                                     u32 bits_wanted, u32 min_bits,
  72                                     u16 *bit_off, u16 *bits_found);
  73 static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
  74                               u32 bits_wanted,
  75                               u32 min_bits,
  76                               u16 *bit_off,
  77                               unsigned int *num_bits,
  78                               u64 *bg_blkno);
  79 static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
  80                                      struct ocfs2_alloc_context *ac,
  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(struct ocfs2_journal_handle *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(struct ocfs2_journal_handle *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(struct ocfs2_journal_handle *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 int ocfs2_free_suballoc_bits(struct ocfs2_journal_handle *handle,
 110                                     struct inode *alloc_inode,
 111                                     struct buffer_head *alloc_bh,
 112                                     unsigned int start_bit,
 113                                     u64 bg_blkno,
 114                                     unsigned int count);
 115 static inline u64 ocfs2_which_suballoc_group(u64 block,
 116                                              unsigned int bit);
 117 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
 118                                                    u64 bg_blkno,
 119                                                    u16 bg_bit_off);
 120 static inline u64 ocfs2_which_cluster_group(struct inode *inode,
 121                                             u32 cluster);
 122 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
 123                                                 u64 data_blkno,
 124                                                 u64 *bg_blkno,
 125                                                 u16 *bg_bit_off);
 126
 127 void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
 128 {
 129         if (ac->ac_inode)
 130                 iput(ac->ac_inode);
 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(struct ocfs2_journal_handle *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         struct ocfs2_journal_handle *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         handle = ocfs2_alloc_handle(osb);
 294         if (!handle) {
 295                 status = -ENOMEM;
 296                 mlog_errno(status);
 297                 goto bail;
 298         }
 299
 300         cl = &fe->id2.i_chain;
 301         status = ocfs2_reserve_clusters(osb,
 302                                         handle,
 303                                         le16_to_cpu(cl->cl_cpg),
 304                                         &ac);
 305         if (status < 0) {
 306                 if (status != -ENOSPC)
 307                         mlog_errno(status);
 308                 goto bail;
 309         }
 310
 311         credits = ocfs2_calc_group_alloc_credits(osb->sb,
 312                                                  le16_to_cpu(cl->cl_cpg));
 313         handle = ocfs2_start_trans(osb, handle, credits);
 314         if (IS_ERR(handle)) {
 315                 status = PTR_ERR(handle);
 316                 handle = NULL;
 317                 mlog_errno(status);
 318                 goto bail;
 319         }
 320
 321         status = ocfs2_claim_clusters(osb,
 322                                       handle,
 323                                       ac,
 324                                       le16_to_cpu(cl->cl_cpg),
 325                                       &bit_off,
 326                                       &num_bits);
 327         if (status < 0) {
 328                 if (status != -ENOSPC)
 329                         mlog_errno(status);
 330                 goto bail;
 331         }
 332
 333         alloc_rec = ocfs2_find_smallest_chain(cl);
 334
 335         /* setup the group */
 336         bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 337         mlog(0, "new descriptor, record %u, at block %llu\n",
 338              alloc_rec, (unsigned long long)bg_blkno);
 339
 340         bg_bh = sb_getblk(osb->sb, bg_blkno);
 341         if (!bg_bh) {
 342                 status = -EIO;
 343                 mlog_errno(status);
 344                 goto bail;
 345         }
 346         ocfs2_set_new_buffer_uptodate(alloc_inode, bg_bh);
 347
 348         status = ocfs2_block_group_fill(handle,
 349                                         alloc_inode,
 350                                         bg_bh,
 351                                         bg_blkno,
 352                                         alloc_rec,
 353                                         cl);
 354         if (status < 0) {
 355                 mlog_errno(status);
 356                 goto bail;
 357         }
 358
 359         bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 360
 361         status = ocfs2_journal_access(handle, alloc_inode,
 362                                       bh, OCFS2_JOURNAL_ACCESS_WRITE);
 363         if (status < 0) {
 364                 mlog_errno(status);
 365                 goto bail;
 366         }
 367
 368         le32_add_cpu(&cl->cl_recs[alloc_rec].c_free,
 369                      le16_to_cpu(bg->bg_free_bits_count));
 370         le32_add_cpu(&cl->cl_recs[alloc_rec].c_total, le16_to_cpu(bg->bg_bits));
 371         cl->cl_recs[alloc_rec].c_blkno  = cpu_to_le64(bg_blkno);
 372         if (le16_to_cpu(cl->cl_next_free_rec) < le16_to_cpu(cl->cl_count))
 373                 le16_add_cpu(&cl->cl_next_free_rec, 1);
 374
 375         le32_add_cpu(&fe->id1.bitmap1.i_used, le16_to_cpu(bg->bg_bits) -
 376                                         le16_to_cpu(bg->bg_free_bits_count));
 377         le32_add_cpu(&fe->id1.bitmap1.i_total, le16_to_cpu(bg->bg_bits));
 378         le32_add_cpu(&fe->i_clusters, le16_to_cpu(cl->cl_cpg));
 379
 380         status = ocfs2_journal_dirty(handle, bh);
 381         if (status < 0) {
 382                 mlog_errno(status);
 383                 goto bail;
 384         }
 385
 386         spin_lock(&OCFS2_I(alloc_inode)->ip_lock);
 387         OCFS2_I(alloc_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
 388         fe->i_size = cpu_to_le64(ocfs2_clusters_to_bytes(alloc_inode->i_sb,
 389                                              le32_to_cpu(fe->i_clusters)));
 390         spin_unlock(&OCFS2_I(alloc_inode)->ip_lock);
 391         i_size_write(alloc_inode, le64_to_cpu(fe->i_size));
 392         alloc_inode->i_blocks =
 393                 ocfs2_align_bytes_to_sectors(i_size_read(alloc_inode));
 394
 395         status = 0;
 396 bail:
 397         if (handle)
 398                 ocfs2_commit_trans(handle);
 399
 400         if (ac)
 401                 ocfs2_free_alloc_context(ac);
 402
 403         if (bg_bh)
 404                 brelse(bg_bh);
 405
 406         mlog_exit(status);
 407         return status;
 408 }
 409
 410 static int ocfs2_reserve_suballoc_bits(struct ocfs2_super *osb,
 411                                        struct ocfs2_alloc_context *ac)
 412 {
 413         int status;
 414         u32 bits_wanted = ac->ac_bits_wanted;
 415         struct inode *alloc_inode = ac->ac_inode;
 416         struct buffer_head *bh = NULL;
 417         struct ocfs2_journal_handle *handle = ac->ac_handle;
 418         struct ocfs2_dinode *fe;
 419         u32 free_bits;
 420
 421         mlog_entry_void();
 422
 423         BUG_ON(handle->flags & OCFS2_HANDLE_STARTED);
 424
 425         ocfs2_handle_add_inode(handle, alloc_inode);
 426         status = ocfs2_meta_lock(alloc_inode, handle, &bh, 1);
 427         if (status < 0) {
 428                 mlog_errno(status);
 429                 goto bail;
 430         }
 431
 432         fe = (struct ocfs2_dinode *) bh->b_data;
 433         if (!OCFS2_IS_VALID_DINODE(fe)) {
 434                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
 435                 status = -EIO;
 436                 goto bail;
 437         }
 438         if (!(fe->i_flags & cpu_to_le32(OCFS2_CHAIN_FL))) {
 439                 ocfs2_error(alloc_inode->i_sb, "Invalid chain allocator %llu",
 440                             (unsigned long long)le64_to_cpu(fe->i_blkno));
 441                 status = -EIO;
 442                 goto bail;
 443         }
 444
 445         free_bits = le32_to_cpu(fe->id1.bitmap1.i_total) -
 446                 le32_to_cpu(fe->id1.bitmap1.i_used);
 447
 448         if (bits_wanted > free_bits) {
 449                 /* cluster bitmap never grows */
 450                 if (ocfs2_is_cluster_bitmap(alloc_inode)) {
 451                         mlog(0, "Disk Full: wanted=%u, free_bits=%u\n",
 452                              bits_wanted, free_bits);
 453                         status = -ENOSPC;
 454                         goto bail;
 455                 }
 456
 457                 status = ocfs2_block_group_alloc(osb, alloc_inode, bh);
 458                 if (status < 0) {
 459                         if (status != -ENOSPC)
 460                                 mlog_errno(status);
 461                         goto bail;
 462                 }
 463                 atomic_inc(&osb->alloc_stats.bg_extends);
 464
 465                 /* You should never ask for this much metadata */
 466                 BUG_ON(bits_wanted >
 467                        (le32_to_cpu(fe->id1.bitmap1.i_total)
 468                         - le32_to_cpu(fe->id1.bitmap1.i_used)));
 469         }
 470
 471         get_bh(bh);
 472         ac->ac_bh = bh;
 473 bail:
 474         if (bh)
 475                 brelse(bh);
 476
 477         mlog_exit(status);
 478         return status;
 479 }
 480
 481 int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
 482                                struct ocfs2_journal_handle *handle,
 483                                struct ocfs2_dinode *fe,
 484                                struct ocfs2_alloc_context **ac)
 485 {
 486         int status;
 487         struct inode *alloc_inode = NULL;
 488
 489         *ac = kcalloc(1, sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 490         if (!(*ac)) {
 491                 status = -ENOMEM;
 492                 mlog_errno(status);
 493                 goto bail;
 494         }
 495
 496         (*ac)->ac_bits_wanted = ocfs2_extend_meta_needed(fe);
 497         (*ac)->ac_handle = handle;
 498         (*ac)->ac_which = OCFS2_AC_USE_META;
 499
 500 #ifndef OCFS2_USE_ALL_METADATA_SUBALLOCATORS
 501         alloc_inode = ocfs2_get_system_file_inode(osb,
 502                                                   EXTENT_ALLOC_SYSTEM_INODE,
 503                                                   0);
 504 #else
 505         alloc_inode = ocfs2_get_system_file_inode(osb,
 506                                                   EXTENT_ALLOC_SYSTEM_INODE,
 507                                                   osb->slot_num);
 508 #endif
 509         if (!alloc_inode) {
 510                 status = -ENOMEM;
 511                 mlog_errno(status);
 512                 goto bail;
 513         }
 514
 515         (*ac)->ac_inode = igrab(alloc_inode);
 516         (*ac)->ac_group_search = ocfs2_block_group_search;
 517
 518         status = ocfs2_reserve_suballoc_bits(osb, (*ac));
 519         if (status < 0) {
 520                 if (status != -ENOSPC)
 521                         mlog_errno(status);
 522                 goto bail;
 523         }
 524
 525         status = 0;
 526 bail:
 527         if ((status < 0) && *ac) {
 528                 ocfs2_free_alloc_context(*ac);
 529                 *ac = NULL;
 530         }
 531
 532         if (alloc_inode)
 533                 iput(alloc_inode);
 534
 535         mlog_exit(status);
 536         return status;
 537 }
 538
 539 int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
 540                             struct ocfs2_journal_handle *handle,
 541                             struct ocfs2_alloc_context **ac)
 542 {
 543         int status;
 544         struct inode *alloc_inode = NULL;
 545
 546         *ac = kcalloc(1, sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 547         if (!(*ac)) {
 548                 status = -ENOMEM;
 549                 mlog_errno(status);
 550                 goto bail;
 551         }
 552
 553         (*ac)->ac_bits_wanted = 1;
 554         (*ac)->ac_handle = handle;
 555         (*ac)->ac_which = OCFS2_AC_USE_INODE;
 556
 557         alloc_inode = ocfs2_get_system_file_inode(osb,
 558                                                   INODE_ALLOC_SYSTEM_INODE,
 559                                                   osb->slot_num);
 560         if (!alloc_inode) {
 561                 status = -ENOMEM;
 562                 mlog_errno(status);
 563                 goto bail;
 564         }
 565
 566         (*ac)->ac_inode = igrab(alloc_inode);
 567         (*ac)->ac_group_search = ocfs2_block_group_search;
 568
 569         status = ocfs2_reserve_suballoc_bits(osb, *ac);
 570         if (status < 0) {
 571                 if (status != -ENOSPC)
 572                         mlog_errno(status);
 573                 goto bail;
 574         }
 575
 576         status = 0;
 577 bail:
 578         if ((status < 0) && *ac) {
 579                 ocfs2_free_alloc_context(*ac);
 580                 *ac = NULL;
 581         }
 582
 583         if (alloc_inode)
 584                 iput(alloc_inode);
 585
 586         mlog_exit(status);
 587         return status;
 588 }
 589
 590 /* local alloc code has to do the same thing, so rather than do this
 591  * twice.. */
 592 int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
 593                                       struct ocfs2_alloc_context *ac)
 594 {
 595         int status;
 596
 597         ac->ac_inode = ocfs2_get_system_file_inode(osb,
 598                                                    GLOBAL_BITMAP_SYSTEM_INODE,
 599                                                    OCFS2_INVALID_SLOT);
 600         if (!ac->ac_inode) {
 601                 status = -EINVAL;
 602                 mlog(ML_ERROR, "Could not get bitmap inode!\n");
 603                 goto bail;
 604         }
 605         ac->ac_which = OCFS2_AC_USE_MAIN;
 606         ac->ac_group_search = ocfs2_cluster_group_search;
 607
 608         status = ocfs2_reserve_suballoc_bits(osb, ac);
 609         if (status < 0 && status != -ENOSPC)
 610                 mlog_errno(status);
 611 bail:
 612         return status;
 613 }
 614
 615 /* Callers don't need to care which bitmap (local alloc or main) to
 616  * use so we figure it out for them, but unfortunately this clutters
 617  * things a bit. */
 618 int ocfs2_reserve_clusters(struct ocfs2_super *osb,
 619                            struct ocfs2_journal_handle *handle,
 620                            u32 bits_wanted,
 621                            struct ocfs2_alloc_context **ac)
 622 {
 623         int status;
 624
 625         mlog_entry_void();
 626
 627         BUG_ON(!handle);
 628
 629         *ac = kcalloc(1, sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 630         if (!(*ac)) {
 631                 status = -ENOMEM;
 632                 mlog_errno(status);
 633                 goto bail;
 634         }
 635
 636         (*ac)->ac_bits_wanted = bits_wanted;
 637         (*ac)->ac_handle = handle;
 638
 639         status = -ENOSPC;
 640         if (ocfs2_alloc_should_use_local(osb, bits_wanted)) {
 641                 status = ocfs2_reserve_local_alloc_bits(osb,
 642                                                         handle,
 643                                                         bits_wanted,
 644                                                         *ac);
 645                 if ((status < 0) && (status != -ENOSPC)) {
 646                         mlog_errno(status);
 647                         goto bail;
 648                 } else if (status == -ENOSPC) {
 649                         /* reserve_local_bits will return enospc with
 650                          * the local alloc inode still locked, so we
 651                          * can change this safely here. */
 652                         mlog(0, "Disabling local alloc\n");
 653                         /* We set to OCFS2_LA_DISABLED so that umount
 654                          * can clean up what's left of the local
 655                          * allocation */
 656                         osb->local_alloc_state = OCFS2_LA_DISABLED;
 657                 }
 658         }
 659
 660         if (status == -ENOSPC) {
 661                 status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
 662                 if (status < 0) {
 663                         if (status != -ENOSPC)
 664                                 mlog_errno(status);
 665                         goto bail;
 666                 }
 667         }
 668
 669         status = 0;
 670 bail:
 671         if ((status < 0) && *ac) {
 672                 ocfs2_free_alloc_context(*ac);
 673                 *ac = NULL;
 674         }
 675
 676         mlog_exit(status);
 677         return status;
 678 }
 679
 680 /*
 681  * More or less lifted from ext3. I'll leave their description below:
 682  *
 683  * "For ext3 allocations, we must not reuse any blocks which are
 684  * allocated in the bitmap buffer's "last committed data" copy.  This
 685  * prevents deletes from freeing up the page for reuse until we have
 686  * committed the delete transaction.
 687  *
 688  * If we didn't do this, then deleting something and reallocating it as
 689  * data would allow the old block to be overwritten before the
 690  * transaction committed (because we force data to disk before commit).
 691  * This would lead to corruption if we crashed between overwriting the
 692  * data and committing the delete.
 693  *
 694  * @@@ We may want to make this allocation behaviour conditional on
 695  * data-writes at some point, and disable it for metadata allocations or
 696  * sync-data inodes."
 697  *
 698  * Note: OCFS2 already does this differently for metadata vs data
 699  * allocations, as those bitmaps are seperate and undo access is never
 700  * called on a metadata group descriptor.
 701  */
 702 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
 703                                          int nr)
 704 {
 705         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 706
 707         if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
 708                 return 0;
 709         if (!buffer_jbd(bg_bh) || !bh2jh(bg_bh)->b_committed_data)
 710                 return 1;
 711
 712         bg = (struct ocfs2_group_desc *) bh2jh(bg_bh)->b_committed_data;
 713         return !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
 714 }
 715
 716 static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
 717                                              struct buffer_head *bg_bh,
 718                                              unsigned int bits_wanted,
 719                                              unsigned int total_bits,
 720                                              u16 *bit_off,
 721                                              u16 *bits_found)
 722 {
 723         void *bitmap;
 724         u16 best_offset, best_size;
 725         int offset, start, found, status = 0;
 726         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 727
 728         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
 729                 OCFS2_RO_ON_INVALID_GROUP_DESC(osb->sb, bg);
 730                 return -EIO;
 731         }
 732
 733         found = start = best_offset = best_size = 0;
 734         bitmap = bg->bg_bitmap;
 735
 736         while((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) != -1) {
 737                 if (offset == total_bits)
 738                         break;
 739
 740                 if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
 741                         /* We found a zero, but we can't use it as it
 742                          * hasn't been put to disk yet! */
 743                         found = 0;
 744                         start = offset + 1;
 745                 } else if (offset == start) {
 746                         /* we found a zero */
 747                         found++;
 748                         /* move start to the next bit to test */
 749                         start++;
 750                 } else {
 751                         /* got a zero after some ones */
 752                         found = 1;
 753                         start = offset + 1;
 754                 }
 755                 if (found > best_size) {
 756                         best_size = found;
 757                         best_offset = start - found;
 758                 }
 759                 /* we got everything we needed */
 760                 if (found == bits_wanted) {
 761                         /* mlog(0, "Found it all!\n"); */
 762                         break;
 763                 }
 764         }
 765
 766         /* XXX: I think the first clause is equivalent to the second
 767          *      - jlbec */
 768         if (found == bits_wanted) {
 769                 *bit_off = start - found;
 770                 *bits_found = found;
 771         } else if (best_size) {
 772                 *bit_off = best_offset;
 773                 *bits_found = best_size;
 774         } else {
 775                 status = -ENOSPC;
 776                 /* No error log here -- see the comment above
 777                  * ocfs2_test_bg_bit_allocatable */
 778         }
 779
 780         return status;
 781 }
 782
 783 static inline int ocfs2_block_group_set_bits(struct ocfs2_journal_handle *handle,
 784                                              struct inode *alloc_inode,
 785                                              struct ocfs2_group_desc *bg,
 786                                              struct buffer_head *group_bh,
 787                                              unsigned int bit_off,
 788                                              unsigned int num_bits)
 789 {
 790         int status;
 791         void *bitmap = bg->bg_bitmap;
 792         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
 793
 794         mlog_entry_void();
 795
 796         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
 797                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
 798                 status = -EIO;
 799                 goto bail;
 800         }
 801         BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
 802
 803         mlog(0, "block_group_set_bits: off = %u, num = %u\n", bit_off,
 804              num_bits);
 805
 806         if (ocfs2_is_cluster_bitmap(alloc_inode))
 807                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
 808
 809         status = ocfs2_journal_access(handle,
 810                                       alloc_inode,
 811                                       group_bh,
 812                                       journal_type);
 813         if (status < 0) {
 814                 mlog_errno(status);
 815                 goto bail;
 816         }
 817
 818         le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
 819
 820         while(num_bits--)
 821                 ocfs2_set_bit(bit_off++, bitmap);
 822
 823         status = ocfs2_journal_dirty(handle,
 824                                      group_bh);
 825         if (status < 0) {
 826                 mlog_errno(status);
 827                 goto bail;
 828         }
 829
 830 bail:
 831         mlog_exit(status);
 832         return status;
 833 }
 834
 835 /* find the one with the most empty bits */
 836 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
 837 {
 838         u16 curr, best;
 839
 840         BUG_ON(!cl->cl_next_free_rec);
 841
 842         best = curr = 0;
 843         while (curr < le16_to_cpu(cl->cl_next_free_rec)) {
 844                 if (le32_to_cpu(cl->cl_recs[curr].c_free) >
 845                     le32_to_cpu(cl->cl_recs[best].c_free))
 846                         best = curr;
 847                 curr++;
 848         }
 849
 850         BUG_ON(best >= le16_to_cpu(cl->cl_next_free_rec));
 851         return best;
 852 }
 853
 854 static int ocfs2_relink_block_group(struct ocfs2_journal_handle *handle,
 855                                     struct inode *alloc_inode,
 856                                     struct buffer_head *fe_bh,
 857                                     struct buffer_head *bg_bh,
 858                                     struct buffer_head *prev_bg_bh,
 859                                     u16 chain)
 860 {
 861         int status;
 862         /* there is a really tiny chance the journal calls could fail,
 863          * but we wouldn't want inconsistent blocks in *any* case. */
 864         u64 fe_ptr, bg_ptr, prev_bg_ptr;
 865         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
 866         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 867         struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
 868
 869         if (!OCFS2_IS_VALID_DINODE(fe)) {
 870                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
 871                 status = -EIO;
 872                 goto out;
 873         }
 874         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
 875                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
 876                 status = -EIO;
 877                 goto out;
 878         }
 879         if (!OCFS2_IS_VALID_GROUP_DESC(prev_bg)) {
 880                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, prev_bg);
 881                 status = -EIO;
 882                 goto out;
 883         }
 884
 885         mlog(0, "Suballoc %llu, chain %u, move group %llu to top, prev = %llu\n",
 886              (unsigned long long)fe->i_blkno, chain,
 887              (unsigned long long)bg->bg_blkno,
 888              (unsigned long long)prev_bg->bg_blkno);
 889
 890         fe_ptr = le64_to_cpu(fe->id2.i_chain.cl_recs[chain].c_blkno);
 891         bg_ptr = le64_to_cpu(bg->bg_next_group);
 892         prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
 893
 894         status = ocfs2_journal_access(handle, alloc_inode, prev_bg_bh,
 895                                       OCFS2_JOURNAL_ACCESS_WRITE);
 896         if (status < 0) {
 897                 mlog_errno(status);
 898                 goto out_rollback;
 899         }
 900
 901         prev_bg->bg_next_group = bg->bg_next_group;
 902
 903         status = ocfs2_journal_dirty(handle, prev_bg_bh);
 904         if (status < 0) {
 905                 mlog_errno(status);
 906                 goto out_rollback;
 907         }
 908
 909         status = ocfs2_journal_access(handle, alloc_inode, bg_bh,
 910                                       OCFS2_JOURNAL_ACCESS_WRITE);
 911         if (status < 0) {
 912                 mlog_errno(status);
 913                 goto out_rollback;
 914         }
 915
 916         bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
 917
 918         status = ocfs2_journal_dirty(handle, bg_bh);
 919         if (status < 0) {
 920                 mlog_errno(status);
 921                 goto out_rollback;
 922         }
 923
 924         status = ocfs2_journal_access(handle, alloc_inode, fe_bh,
 925                                       OCFS2_JOURNAL_ACCESS_WRITE);
 926         if (status < 0) {
 927                 mlog_errno(status);
 928                 goto out_rollback;
 929         }
 930
 931         fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
 932
 933         status = ocfs2_journal_dirty(handle, fe_bh);
 934         if (status < 0) {
 935                 mlog_errno(status);
 936                 goto out_rollback;
 937         }
 938
 939         status = 0;
 940 out_rollback:
 941         if (status < 0) {
 942                 fe->id2.i_chain.cl_recs[chain].c_blkno = cpu_to_le64(fe_ptr);
 943                 bg->bg_next_group = cpu_to_le64(bg_ptr);
 944                 prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
 945         }
 946 out:
 947         mlog_exit(status);
 948         return status;
 949 }
 950
 951 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
 952                                                      u32 wanted)
 953 {
 954         return le16_to_cpu(bg->bg_free_bits_count) > wanted;
 955 }
 956
 957 /* return 0 on success, -ENOSPC to keep searching and any other < 0
 958  * value on error. */
 959 static int ocfs2_cluster_group_search(struct inode *inode,
 960                                       struct buffer_head *group_bh,
 961                                       u32 bits_wanted, u32 min_bits,
 962                                       u16 *bit_off, u16 *bits_found)
 963 {
 964         int search = -ENOSPC;
 965         int ret;
 966         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
 967         u16 tmp_off, tmp_found;
 968         unsigned int max_bits, gd_cluster_off;
 969
 970         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
 971
 972         if (gd->bg_free_bits_count) {
 973                 max_bits = le16_to_cpu(gd->bg_bits);
 974
 975                 /* Tail groups in cluster bitmaps which aren't cpg
 976                  * aligned are prone to partial extention by a failed
 977                  * fs resize. If the file system resize never got to
 978                  * update the dinode cluster count, then we don't want
 979                  * to trust any clusters past it, regardless of what
 980                  * the group descriptor says. */
 981                 gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
 982                                                           le64_to_cpu(gd->bg_blkno));
 983                 if ((gd_cluster_off + max_bits) >
 984                     OCFS2_I(inode)->ip_clusters) {
 985                         max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
 986                         mlog(0, "Desc %llu, bg_bits %u, clusters %u, use %u\n",
 987                              (unsigned long long)le64_to_cpu(gd->bg_blkno),
 988                              le16_to_cpu(gd->bg_bits),
 989                              OCFS2_I(inode)->ip_clusters, max_bits);
 990                 }
 991
 992                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
 993                                                         group_bh, bits_wanted,
 994                                                         max_bits,
 995                                                         &tmp_off, &tmp_found);
 996                 if (ret)
 997                         return ret;
 998
 999                 /* ocfs2_block_group_find_clear_bits() might
1000                  * return success, but we still want to return
1001                  * -ENOSPC unless it found the minimum number
1002                  * of bits. */
1003                 if (min_bits <= tmp_found) {
1004                         *bit_off = tmp_off;
1005                         *bits_found = tmp_found;
1006                         search = 0; /* success */
1007                 }
1008         }
1009
1010         return search;
1011 }
1012
1013 static int ocfs2_block_group_search(struct inode *inode,
1014                                     struct buffer_head *group_bh,
1015                                     u32 bits_wanted, u32 min_bits,
1016                                     u16 *bit_off, u16 *bits_found)
1017 {
1018         int ret = -ENOSPC;
1019         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
1020
1021         BUG_ON(min_bits != 1);
1022         BUG_ON(ocfs2_is_cluster_bitmap(inode));
1023
1024         if (bg->bg_free_bits_count)
1025                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1026                                                         group_bh, bits_wanted,
1027                                                         le16_to_cpu(bg->bg_bits),
1028                                                         bit_off, bits_found);
1029
1030         return ret;
1031 }
1032
1033 static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
1034                               u32 bits_wanted,
1035                               u32 min_bits,
1036                               u16 *bit_off,
1037                               unsigned int *num_bits,
1038                               u64 *bg_blkno)
1039 {
1040         int status;
1041         u16 chain, tmp_bits;
1042         u32 tmp_used;
1043         u64 next_group;
1044         struct ocfs2_journal_handle *handle = ac->ac_handle;
1045         struct inode *alloc_inode = ac->ac_inode;
1046         struct buffer_head *group_bh = NULL;
1047         struct buffer_head *prev_group_bh = NULL;
1048         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1049         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1050         struct ocfs2_group_desc *bg;
1051
1052         chain = ac->ac_chain;
1053         mlog(0, "trying to alloc %u bits from chain %u, inode %llu\n",
1054              bits_wanted, chain,
1055              (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno);
1056
1057         status = ocfs2_read_block(OCFS2_SB(alloc_inode->i_sb),
1058                                   le64_to_cpu(cl->cl_recs[chain].c_blkno),
1059                                   &group_bh, OCFS2_BH_CACHED, alloc_inode);
1060         if (status < 0) {
1061                 mlog_errno(status);
1062                 goto bail;
1063         }
1064         bg = (struct ocfs2_group_desc *) group_bh->b_data;
1065         status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, bg);
1066         if (status) {
1067                 mlog_errno(status);
1068                 goto bail;
1069         }
1070
1071         status = -ENOSPC;
1072         /* for now, the chain search is a bit simplistic. We just use
1073          * the 1st group with any empty bits. */
1074         while ((status = ac->ac_group_search(alloc_inode, group_bh,
1075                                              bits_wanted, min_bits, bit_off,
1076                                              &tmp_bits)) == -ENOSPC) {
1077                 if (!bg->bg_next_group)
1078                         break;
1079
1080                 if (prev_group_bh) {
1081                         brelse(prev_group_bh);
1082                         prev_group_bh = NULL;
1083                 }
1084                 next_group = le64_to_cpu(bg->bg_next_group);
1085                 prev_group_bh = group_bh;
1086                 group_bh = NULL;
1087                 status = ocfs2_read_block(OCFS2_SB(alloc_inode->i_sb),
1088                                           next_group, &group_bh,
1089                                           OCFS2_BH_CACHED, alloc_inode);
1090                 if (status < 0) {
1091                         mlog_errno(status);
1092                         goto bail;
1093                 }
1094                 bg = (struct ocfs2_group_desc *) group_bh->b_data;
1095                 status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, bg);
1096                 if (status) {
1097                         mlog_errno(status);
1098                         goto bail;
1099                 }
1100         }
1101         if (status < 0) {
1102                 if (status != -ENOSPC)
1103                         mlog_errno(status);
1104                 goto bail;
1105         }
1106
1107         mlog(0, "alloc succeeds: we give %u bits from block group %llu\n",
1108              tmp_bits, (unsigned long long)bg->bg_blkno);
1109
1110         *num_bits = tmp_bits;
1111
1112         BUG_ON(*num_bits == 0);
1113
1114         /*
1115          * Keep track of previous block descriptor read. When
1116          * we find a target, if we have read more than X
1117          * number of descriptors, and the target is reasonably
1118          * empty, relink him to top of his chain.
1119          *
1120          * We've read 0 extra blocks and only send one more to
1121          * the transaction, yet the next guy to search has a
1122          * much easier time.
1123          *
1124          * Do this *after* figuring out how many bits we're taking out
1125          * of our target group.
1126          */
1127         if (ac->ac_allow_chain_relink &&
1128             (prev_group_bh) &&
1129             (ocfs2_block_group_reasonably_empty(bg, *num_bits))) {
1130                 status = ocfs2_relink_block_group(handle, alloc_inode,
1131                                                   ac->ac_bh, group_bh,
1132                                                   prev_group_bh, chain);
1133                 if (status < 0) {
1134                         mlog_errno(status);
1135                         goto bail;
1136                 }
1137         }
1138
1139         /* Ok, claim our bits now: set the info on dinode, chainlist
1140          * and then the group */
1141         status = ocfs2_journal_access(handle,
1142                                       alloc_inode,
1143                                       ac->ac_bh,
1144                                       OCFS2_JOURNAL_ACCESS_WRITE);
1145         if (status < 0) {
1146                 mlog_errno(status);
1147                 goto bail;
1148         }
1149
1150         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
1151         fe->id1.bitmap1.i_used = cpu_to_le32(*num_bits + tmp_used);
1152         le32_add_cpu(&cl->cl_recs[chain].c_free, -(*num_bits));
1153
1154         status = ocfs2_journal_dirty(handle,
1155                                      ac->ac_bh);
1156         if (status < 0) {
1157                 mlog_errno(status);
1158                 goto bail;
1159         }
1160
1161         status = ocfs2_block_group_set_bits(handle,
1162                                             alloc_inode,
1163                                             bg,
1164                                             group_bh,
1165                                             *bit_off,
1166                                             *num_bits);
1167         if (status < 0) {
1168                 mlog_errno(status);
1169                 goto bail;
1170         }
1171
1172         mlog(0, "Allocated %u bits from suballocator %llu\n", *num_bits,
1173              (unsigned long long)fe->i_blkno);
1174
1175         *bg_blkno = le64_to_cpu(bg->bg_blkno);
1176 bail:
1177         if (group_bh)
1178                 brelse(group_bh);
1179         if (prev_group_bh)
1180                 brelse(prev_group_bh);
1181
1182         mlog_exit(status);
1183         return status;
1184 }
1185
1186 /* will give out up to bits_wanted contiguous bits. */
1187 static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
1188                                      struct ocfs2_alloc_context *ac,
1189                                      u32 bits_wanted,
1190                                      u32 min_bits,
1191                                      u16 *bit_off,
1192                                      unsigned int *num_bits,
1193                                      u64 *bg_blkno)
1194 {
1195         int status;
1196         u16 victim, i;
1197         struct ocfs2_chain_list *cl;
1198         struct ocfs2_dinode *fe;
1199
1200         mlog_entry_void();
1201
1202         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1203         BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1204         BUG_ON(!ac->ac_bh);
1205
1206         fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1207         if (!OCFS2_IS_VALID_DINODE(fe)) {
1208                 OCFS2_RO_ON_INVALID_DINODE(osb->sb, fe);
1209                 status = -EIO;
1210                 goto bail;
1211         }
1212         if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1213             le32_to_cpu(fe->id1.bitmap1.i_total)) {
1214                 ocfs2_error(osb->sb, "Chain allocator dinode %llu has %u used "
1215                             "bits but only %u total.",
1216                             (unsigned long long)le64_to_cpu(fe->i_blkno),
1217                             le32_to_cpu(fe->id1.bitmap1.i_used),
1218                             le32_to_cpu(fe->id1.bitmap1.i_total));
1219                 status = -EIO;
1220                 goto bail;
1221         }
1222
1223         cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1224
1225         victim = ocfs2_find_victim_chain(cl);
1226         ac->ac_chain = victim;
1227         ac->ac_allow_chain_relink = 1;
1228
1229         status = ocfs2_search_chain(ac, bits_wanted, min_bits, bit_off,
1230                                     num_bits, bg_blkno);
1231         if (!status)
1232                 goto bail;
1233         if (status < 0 && status != -ENOSPC) {
1234                 mlog_errno(status);
1235                 goto bail;
1236         }
1237
1238         mlog(0, "Search of victim chain %u came up with nothing, "
1239              "trying all chains now.\n", victim);
1240
1241         /* If we didn't pick a good victim, then just default to
1242          * searching each chain in order. Don't allow chain relinking
1243          * because we only calculate enough journal credits for one
1244          * relink per alloc. */
1245         ac->ac_allow_chain_relink = 0;
1246         for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
1247                 if (i == victim)
1248                         continue;
1249                 if (!cl->cl_recs[i].c_free)
1250                         continue;
1251
1252                 ac->ac_chain = i;
1253                 status = ocfs2_search_chain(ac, bits_wanted, min_bits,
1254                                             bit_off, num_bits,
1255                                             bg_blkno);
1256                 if (!status)
1257                         break;
1258                 if (status < 0 && status != -ENOSPC) {
1259                         mlog_errno(status);
1260                         goto bail;
1261                 }
1262         }
1263 bail:
1264
1265         mlog_exit(status);
1266         return status;
1267 }
1268
1269 int ocfs2_claim_metadata(struct ocfs2_super *osb,
1270                          struct ocfs2_journal_handle *handle,
1271                          struct ocfs2_alloc_context *ac,
1272                          u32 bits_wanted,
1273                          u16 *suballoc_bit_start,
1274                          unsigned int *num_bits,
1275                          u64 *blkno_start)
1276 {
1277         int status;
1278         u64 bg_blkno;
1279
1280         BUG_ON(!ac);
1281         BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
1282         BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
1283         BUG_ON(ac->ac_handle != handle);
1284
1285         status = ocfs2_claim_suballoc_bits(osb,
1286                                            ac,
1287                                            bits_wanted,
1288                                            1,
1289                                            suballoc_bit_start,
1290                                            num_bits,
1291                                            &bg_blkno);
1292         if (status < 0) {
1293                 mlog_errno(status);
1294                 goto bail;
1295         }
1296         atomic_inc(&osb->alloc_stats.bg_allocs);
1297
1298         *blkno_start = bg_blkno + (u64) *suballoc_bit_start;
1299         ac->ac_bits_given += (*num_bits);
1300         status = 0;
1301 bail:
1302         mlog_exit(status);
1303         return status;
1304 }
1305
1306 int ocfs2_claim_new_inode(struct ocfs2_super *osb,
1307                           struct ocfs2_journal_handle *handle,
1308                           struct ocfs2_alloc_context *ac,
1309                           u16 *suballoc_bit,
1310                           u64 *fe_blkno)
1311 {
1312         int status;
1313         unsigned int num_bits;
1314         u64 bg_blkno;
1315
1316         mlog_entry_void();
1317
1318         BUG_ON(!ac);
1319         BUG_ON(ac->ac_bits_given != 0);
1320         BUG_ON(ac->ac_bits_wanted != 1);
1321         BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
1322         BUG_ON(ac->ac_handle != handle);
1323
1324         status = ocfs2_claim_suballoc_bits(osb,
1325                                            ac,
1326                                            1,
1327                                            1,
1328                                            suballoc_bit,
1329                                            &num_bits,
1330                                            &bg_blkno);
1331         if (status < 0) {
1332                 mlog_errno(status);
1333                 goto bail;
1334         }
1335         atomic_inc(&osb->alloc_stats.bg_allocs);
1336
1337         BUG_ON(num_bits != 1);
1338
1339         *fe_blkno = bg_blkno + (u64) (*suballoc_bit);
1340         ac->ac_bits_given++;
1341         status = 0;
1342 bail:
1343         mlog_exit(status);
1344         return status;
1345 }
1346
1347 /* translate a group desc. blkno and it's bitmap offset into
1348  * disk cluster offset. */
1349 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
1350                                                    u64 bg_blkno,
1351                                                    u16 bg_bit_off)
1352 {
1353         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1354         u32 cluster = 0;
1355
1356         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1357
1358         if (bg_blkno != osb->first_cluster_group_blkno)
1359                 cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
1360         cluster += (u32) bg_bit_off;
1361         return cluster;
1362 }
1363
1364 /* given a cluster offset, calculate which block group it belongs to
1365  * and return that block offset. */
1366 static inline u64 ocfs2_which_cluster_group(struct inode *inode,
1367                                             u32 cluster)
1368 {
1369         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1370         u32 group_no;
1371
1372         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1373
1374         group_no = cluster / osb->bitmap_cpg;
1375         if (!group_no)
1376                 return osb->first_cluster_group_blkno;
1377         return ocfs2_clusters_to_blocks(inode->i_sb,
1378                                         group_no * osb->bitmap_cpg);
1379 }
1380
1381 /* given the block number of a cluster start, calculate which cluster
1382  * group and descriptor bitmap offset that corresponds to. */
1383 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
1384                                                 u64 data_blkno,
1385                                                 u64 *bg_blkno,
1386                                                 u16 *bg_bit_off)
1387 {
1388         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1389         u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
1390
1391         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1392
1393         *bg_blkno = ocfs2_which_cluster_group(inode,
1394                                               data_cluster);
1395
1396         if (*bg_blkno == osb->first_cluster_group_blkno)
1397                 *bg_bit_off = (u16) data_cluster;
1398         else
1399                 *bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
1400                                                              data_blkno - *bg_blkno);
1401 }
1402
1403 /*
1404  * min_bits - minimum contiguous chunk from this total allocation we
1405  * can handle. set to what we asked for originally for a full
1406  * contig. allocation, set to '1' to indicate we can deal with extents
1407  * of any size.
1408  */
1409 int ocfs2_claim_clusters(struct ocfs2_super *osb,
1410                          struct ocfs2_journal_handle *handle,
1411                          struct ocfs2_alloc_context *ac,
1412                          u32 min_clusters,
1413                          u32 *cluster_start,
1414                          u32 *num_clusters)
1415 {
1416         int status;
1417         unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
1418         u64 bg_blkno;
1419         u16 bg_bit_off;
1420
1421         mlog_entry_void();
1422
1423         BUG_ON(!ac);
1424         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1425
1426         BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
1427                && ac->ac_which != OCFS2_AC_USE_MAIN);
1428         BUG_ON(ac->ac_handle != handle);
1429
1430         if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
1431                 status = ocfs2_claim_local_alloc_bits(osb,
1432                                                       handle,
1433                                                       ac,
1434                                                       bits_wanted,
1435                                                       cluster_start,
1436                                                       num_clusters);
1437                 if (!status)
1438                         atomic_inc(&osb->alloc_stats.local_data);
1439         } else {
1440                 if (min_clusters > (osb->bitmap_cpg - 1)) {
1441                         /* The only paths asking for contiguousness
1442                          * should know about this already. */
1443                         mlog(ML_ERROR, "minimum allocation requested exceeds "
1444                                        "group bitmap size!");
1445                         status = -ENOSPC;
1446                         goto bail;
1447                 }
1448                 /* clamp the current request down to a realistic size. */
1449                 if (bits_wanted > (osb->bitmap_cpg - 1))
1450                         bits_wanted = osb->bitmap_cpg - 1;
1451
1452                 status = ocfs2_claim_suballoc_bits(osb,
1453                                                    ac,
1454                                                    bits_wanted,
1455                                                    min_clusters,
1456                                                    &bg_bit_off,
1457                                                    num_clusters,
1458                                                    &bg_blkno);
1459                 if (!status) {
1460                         *cluster_start =
1461                                 ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
1462                                                                  bg_blkno,
1463                                                                  bg_bit_off);
1464                         atomic_inc(&osb->alloc_stats.bitmap_data);
1465                 }
1466         }
1467         if (status < 0) {
1468                 if (status != -ENOSPC)
1469                         mlog_errno(status);
1470                 goto bail;
1471         }
1472
1473         ac->ac_bits_given += *num_clusters;
1474
1475 bail:
1476         mlog_exit(status);
1477         return status;
1478 }
1479
1480 static inline int ocfs2_block_group_clear_bits(struct ocfs2_journal_handle *handle,
1481                                                struct inode *alloc_inode,
1482                                                struct ocfs2_group_desc *bg,
1483                                                struct buffer_head *group_bh,
1484                                                unsigned int bit_off,
1485                                                unsigned int num_bits)
1486 {
1487         int status;
1488         unsigned int tmp;
1489         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1490         struct ocfs2_group_desc *undo_bg = NULL;
1491
1492         mlog_entry_void();
1493
1494         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
1495                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
1496                 status = -EIO;
1497                 goto bail;
1498         }
1499
1500         mlog(0, "off = %u, num = %u\n", bit_off, num_bits);
1501
1502         if (ocfs2_is_cluster_bitmap(alloc_inode))
1503                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1504
1505         status = ocfs2_journal_access(handle, alloc_inode, group_bh,
1506                                       journal_type);
1507         if (status < 0) {
1508                 mlog_errno(status);
1509                 goto bail;
1510         }
1511
1512         if (ocfs2_is_cluster_bitmap(alloc_inode))
1513                 undo_bg = (struct ocfs2_group_desc *) bh2jh(group_bh)->b_committed_data;
1514
1515         tmp = num_bits;
1516         while(tmp--) {
1517                 ocfs2_clear_bit((bit_off + tmp),
1518                                 (unsigned long *) bg->bg_bitmap);
1519                 if (ocfs2_is_cluster_bitmap(alloc_inode))
1520                         ocfs2_set_bit(bit_off + tmp,
1521                                       (unsigned long *) undo_bg->bg_bitmap);
1522         }
1523         le16_add_cpu(&bg->bg_free_bits_count, num_bits);
1524
1525         status = ocfs2_journal_dirty(handle, group_bh);
1526         if (status < 0)
1527                 mlog_errno(status);
1528 bail:
1529         return status;
1530 }
1531
1532 /*
1533  * expects the suballoc inode to already be locked.
1534  */
1535 static int ocfs2_free_suballoc_bits(struct ocfs2_journal_handle *handle,
1536                                     struct inode *alloc_inode,
1537                                     struct buffer_head *alloc_bh,
1538                                     unsigned int start_bit,
1539                                     u64 bg_blkno,
1540                                     unsigned int count)
1541 {
1542         int status = 0;
1543         u32 tmp_used;
1544         struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
1545         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
1546         struct ocfs2_chain_list *cl = &fe->id2.i_chain;
1547         struct buffer_head *group_bh = NULL;
1548         struct ocfs2_group_desc *group;
1549
1550         mlog_entry_void();
1551
1552         if (!OCFS2_IS_VALID_DINODE(fe)) {
1553                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
1554                 status = -EIO;
1555                 goto bail;
1556         }
1557         BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
1558
1559         mlog(0, "%llu: freeing %u bits from group %llu, starting at %u\n",
1560              (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno, count,
1561              (unsigned long long)bg_blkno, start_bit);
1562
1563         status = ocfs2_read_block(osb, bg_blkno, &group_bh, OCFS2_BH_CACHED,
1564                                   alloc_inode);
1565         if (status < 0) {
1566                 mlog_errno(status);
1567                 goto bail;
1568         }
1569
1570         group = (struct ocfs2_group_desc *) group_bh->b_data;
1571         status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, group);
1572         if (status) {
1573                 mlog_errno(status);
1574                 goto bail;
1575         }
1576         BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
1577
1578         status = ocfs2_block_group_clear_bits(handle, alloc_inode,
1579                                               group, group_bh,
1580                                               start_bit, count);
1581         if (status < 0) {
1582                 mlog_errno(status);
1583                 goto bail;
1584         }
1585
1586         status = ocfs2_journal_access(handle, alloc_inode, alloc_bh,
1587                                       OCFS2_JOURNAL_ACCESS_WRITE);
1588         if (status < 0) {
1589                 mlog_errno(status);
1590                 goto bail;
1591         }
1592
1593         le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
1594                      count);
1595         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
1596         fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
1597
1598         status = ocfs2_journal_dirty(handle, alloc_bh);
1599         if (status < 0) {
1600                 mlog_errno(status);
1601                 goto bail;
1602         }
1603
1604 bail:
1605         if (group_bh)
1606                 brelse(group_bh);
1607
1608         mlog_exit(status);
1609         return status;
1610 }
1611
1612 static inline u64 ocfs2_which_suballoc_group(u64 block, unsigned int bit)
1613 {
1614         u64 group = block - (u64) bit;
1615
1616         return group;
1617 }
1618
1619 int ocfs2_free_dinode(struct ocfs2_journal_handle *handle,
1620                       struct inode *inode_alloc_inode,
1621                       struct buffer_head *inode_alloc_bh,
1622                       struct ocfs2_dinode *di)
1623 {
1624         u64 blk = le64_to_cpu(di->i_blkno);
1625         u16 bit = le16_to_cpu(di->i_suballoc_bit);
1626         u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
1627
1628         return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
1629                                         inode_alloc_bh, bit, bg_blkno, 1);
1630 }
1631
1632 int ocfs2_free_extent_block(struct ocfs2_journal_handle *handle,
1633                             struct inode *eb_alloc_inode,
1634                             struct buffer_head *eb_alloc_bh,
1635                             struct ocfs2_extent_block *eb)
1636 {
1637         u64 blk = le64_to_cpu(eb->h_blkno);
1638         u16 bit = le16_to_cpu(eb->h_suballoc_bit);
1639         u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
1640
1641         return ocfs2_free_suballoc_bits(handle, eb_alloc_inode, eb_alloc_bh,
1642                                         bit, bg_blkno, 1);
1643 }
1644
1645 int ocfs2_free_clusters(struct ocfs2_journal_handle *handle,
1646                        struct inode *bitmap_inode,
1647                        struct buffer_head *bitmap_bh,
1648                        u64 start_blk,
1649                        unsigned int num_clusters)
1650 {
1651         int status;
1652         u16 bg_start_bit;
1653         u64 bg_blkno;
1654         struct ocfs2_dinode *fe;
1655
1656         /* You can't ever have a contiguous set of clusters
1657          * bigger than a block group bitmap so we never have to worry
1658          * about looping on them. */
1659
1660         mlog_entry_void();
1661
1662         /* This is expensive. We can safely remove once this stuff has
1663          * gotten tested really well. */
1664         BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb, ocfs2_blocks_to_clusters(bitmap_inode->i_sb, start_blk)));
1665
1666         fe = (struct ocfs2_dinode *) bitmap_bh->b_data;
1667
1668         ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
1669                                      &bg_start_bit);
1670
1671         mlog(0, "want to free %u clusters starting at block %llu\n",
1672              num_clusters, (unsigned long long)start_blk);
1673         mlog(0, "bg_blkno = %llu, bg_start_bit = %u\n",
1674              (unsigned long long)bg_blkno, bg_start_bit);
1675
1676         status = ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
1677                                           bg_start_bit, bg_blkno,
1678                                           num_clusters);
1679         if (status < 0)
1680                 mlog_errno(status);
1681
1682         mlog_exit(status);
1683         return status;
1684 }
1685
1686 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg)
1687 {
1688         printk("Block Group:\n");
1689         printk("bg_signature:       %s\n", bg->bg_signature);
1690         printk("bg_size:            %u\n", bg->bg_size);
1691         printk("bg_bits:            %u\n", bg->bg_bits);
1692         printk("bg_free_bits_count: %u\n", bg->bg_free_bits_count);
1693         printk("bg_chain:           %u\n", bg->bg_chain);
1694         printk("bg_generation:      %u\n", le32_to_cpu(bg->bg_generation));
1695         printk("bg_next_group:      %llu\n",
1696                (unsigned long long)bg->bg_next_group);
1697         printk("bg_parent_dinode:   %llu\n",
1698                (unsigned long long)bg->bg_parent_dinode);
1699         printk("bg_blkno:           %llu\n",
1700                (unsigned long long)bg->bg_blkno);
1701 }
1702
1703 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe)
1704 {
1705         int i;
1706
1707         printk("Suballoc Inode %llu:\n", (unsigned long long)fe->i_blkno);
1708         printk("i_signature:                  %s\n", fe->i_signature);
1709         printk("i_size:                       %llu\n",
1710                (unsigned long long)fe->i_size);
1711         printk("i_clusters:                   %u\n", fe->i_clusters);
1712         printk("i_generation:                 %u\n",
1713                le32_to_cpu(fe->i_generation));
1714         printk("id1.bitmap1.i_used:           %u\n",
1715                le32_to_cpu(fe->id1.bitmap1.i_used));
1716         printk("id1.bitmap1.i_total:          %u\n",
1717                le32_to_cpu(fe->id1.bitmap1.i_total));
1718         printk("id2.i_chain.cl_cpg:           %u\n", fe->id2.i_chain.cl_cpg);
1719         printk("id2.i_chain.cl_bpc:           %u\n", fe->id2.i_chain.cl_bpc);
1720         printk("id2.i_chain.cl_count:         %u\n", fe->id2.i_chain.cl_count);
1721         printk("id2.i_chain.cl_next_free_rec: %u\n",
1722                fe->id2.i_chain.cl_next_free_rec);
1723         for(i = 0; i < fe->id2.i_chain.cl_next_free_rec; i++) {
1724                 printk("fe->id2.i_chain.cl_recs[%d].c_free:  %u\n", i,
1725                        fe->id2.i_chain.cl_recs[i].c_free);
1726                 printk("fe->id2.i_chain.cl_recs[%d].c_total: %u\n", i,
1727                        fe->id2.i_chain.cl_recs[i].c_total);
1728                 printk("fe->id2.i_chain.cl_recs[%d].c_blkno: %llu\n", i,
1729                        (unsigned long long)fe->id2.i_chain.cl_recs[i].c_blkno);
1730         }
1731 }