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   1 /* -*- mode: c; c-basic-offset: 8; -*-
   2  * vim: noexpandtab sw=8 ts=8 sts=0:
   3  *
   4  * suballoc.c
   5  *
   6  * metadata alloc and free
   7  * Inspired by ext3 block groups.
   8  *
   9  * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public
  13  * License as published by the Free Software Foundation; either
  14  * version 2 of the License, or (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19  * General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public
  22  * License along with this program; if not, write to the
  23  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  24  * Boston, MA 021110-1307, USA.
  25  */
  26
  27 #include <linux/fs.h>
  28 #include <linux/types.h>
  29 #include <linux/slab.h>
  30 #include <linux/highmem.h>
  31
  32 #define MLOG_MASK_PREFIX ML_DISK_ALLOC
  33 #include <cluster/masklog.h>
  34
  35 #include "ocfs2.h"
  36
  37 #include "alloc.h"
  38 #include "dlmglue.h"
  39 #include "inode.h"
  40 #include "journal.h"
  41 #include "localalloc.h"
  42 #include "suballoc.h"
  43 #include "super.h"
  44 #include "sysfile.h"
  45 #include "uptodate.h"
  46
  47 #include "buffer_head_io.h"
  48
  49 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg);
  50 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe);
  51 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl);
  52 static int ocfs2_block_group_fill(handle_t *handle,
  53                                   struct inode *alloc_inode,
  54                                   struct buffer_head *bg_bh,
  55                                   u64 group_blkno,
  56                                   u16 my_chain,
  57                                   struct ocfs2_chain_list *cl);
  58 static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
  59                                    struct inode *alloc_inode,
  60                                    struct buffer_head *bh);
  61
  62 static int ocfs2_cluster_group_search(struct inode *inode,
  63                                       struct buffer_head *group_bh,
  64                                       u32 bits_wanted, u32 min_bits,
  65                                       u16 *bit_off, u16 *bits_found);
  66 static int ocfs2_block_group_search(struct inode *inode,
  67                                     struct buffer_head *group_bh,
  68                                     u32 bits_wanted, u32 min_bits,
  69                                     u16 *bit_off, u16 *bits_found);
  70 static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
  71                                      struct ocfs2_alloc_context *ac,
  72                                      handle_t *handle,
  73                                      u32 bits_wanted,
  74                                      u32 min_bits,
  75                                      u16 *bit_off,
  76                                      unsigned int *num_bits,
  77                                      u64 *bg_blkno);
  78 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
  79                                          int nr);
  80 static inline int ocfs2_block_group_set_bits(handle_t *handle,
  81                                              struct inode *alloc_inode,
  82                                              struct ocfs2_group_desc *bg,
  83                                              struct buffer_head *group_bh,
  84                                              unsigned int bit_off,
  85                                              unsigned int num_bits);
  86 static inline int ocfs2_block_group_clear_bits(handle_t *handle,
  87                                                struct inode *alloc_inode,
  88                                                struct ocfs2_group_desc *bg,
  89                                                struct buffer_head *group_bh,
  90                                                unsigned int bit_off,
  91                                                unsigned int num_bits);
  92
  93 static int ocfs2_relink_block_group(handle_t *handle,
  94                                     struct inode *alloc_inode,
  95                                     struct buffer_head *fe_bh,
  96                                     struct buffer_head *bg_bh,
  97                                     struct buffer_head *prev_bg_bh,
  98                                     u16 chain);
  99 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
 100                                                      u32 wanted);
 101 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
 102                                                    u64 bg_blkno,
 103                                                    u16 bg_bit_off);
 104 static inline u64 ocfs2_which_cluster_group(struct inode *inode,
 105                                             u32 cluster);
 106 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
 107                                                 u64 data_blkno,
 108                                                 u64 *bg_blkno,
 109                                                 u16 *bg_bit_off);
 110
 111 void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
 112 {
 113         struct inode *inode = ac->ac_inode;
 114
 115         if (inode) {
 116                 if (ac->ac_which != OCFS2_AC_USE_LOCAL)
 117                         ocfs2_meta_unlock(inode, 1);
 118
 119                 mutex_unlock(&inode->i_mutex);
 120
 121                 iput(inode);
 122         }
 123         if (ac->ac_bh)
 124                 brelse(ac->ac_bh);
 125         kfree(ac);
 126 }
 127
 128 static u32 ocfs2_bits_per_group(struct ocfs2_chain_list *cl)
 129 {
 130         return (u32)le16_to_cpu(cl->cl_cpg) * (u32)le16_to_cpu(cl->cl_bpc);
 131 }
 132
 133 /* somewhat more expensive than our other checks, so use sparingly. */
 134 static int ocfs2_check_group_descriptor(struct super_block *sb,
 135                                         struct ocfs2_dinode *di,
 136                                         struct ocfs2_group_desc *gd)
 137 {
 138         unsigned int max_bits;
 139
 140         if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
 141                 OCFS2_RO_ON_INVALID_GROUP_DESC(sb, gd);
 142                 return -EIO;
 143         }
 144
 145         if (di->i_blkno != gd->bg_parent_dinode) {
 146                 ocfs2_error(sb, "Group descriptor # %llu has bad parent "
 147                             "pointer (%llu, expected %llu)",
 148                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 149                             (unsigned long long)le64_to_cpu(gd->bg_parent_dinode),
 150                             (unsigned long long)le64_to_cpu(di->i_blkno));
 151                 return -EIO;
 152         }
 153
 154         max_bits = le16_to_cpu(di->id2.i_chain.cl_cpg) * le16_to_cpu(di->id2.i_chain.cl_bpc);
 155         if (le16_to_cpu(gd->bg_bits) > max_bits) {
 156                 ocfs2_error(sb, "Group descriptor # %llu has bit count of %u",
 157                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 158                             le16_to_cpu(gd->bg_bits));
 159                 return -EIO;
 160         }
 161
 162         if (le16_to_cpu(gd->bg_chain) >=
 163             le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) {
 164                 ocfs2_error(sb, "Group descriptor # %llu has bad chain %u",
 165                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 166                             le16_to_cpu(gd->bg_chain));
 167                 return -EIO;
 168         }
 169
 170         if (le16_to_cpu(gd->bg_free_bits_count) > le16_to_cpu(gd->bg_bits)) {
 171                 ocfs2_error(sb, "Group descriptor # %llu has bit count %u but "
 172                             "claims that %u are free",
 173                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 174                             le16_to_cpu(gd->bg_bits),
 175                             le16_to_cpu(gd->bg_free_bits_count));
 176                 return -EIO;
 177         }
 178
 179         if (le16_to_cpu(gd->bg_bits) > (8 * le16_to_cpu(gd->bg_size))) {
 180                 ocfs2_error(sb, "Group descriptor # %llu has bit count %u but "
 181                             "max bitmap bits of %u",
 182                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
 183                             le16_to_cpu(gd->bg_bits),
 184                             8 * le16_to_cpu(gd->bg_size));
 185                 return -EIO;
 186         }
 187
 188         return 0;
 189 }
 190
 191 static int ocfs2_block_group_fill(handle_t *handle,
 192                                   struct inode *alloc_inode,
 193                                   struct buffer_head *bg_bh,
 194                                   u64 group_blkno,
 195                                   u16 my_chain,
 196                                   struct ocfs2_chain_list *cl)
 197 {
 198         int status = 0;
 199         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 200         struct super_block * sb = alloc_inode->i_sb;
 201
 202         mlog_entry_void();
 203
 204         if (((unsigned long long) bg_bh->b_blocknr) != group_blkno) {
 205                 ocfs2_error(alloc_inode->i_sb, "group block (%llu) != "
 206                             "b_blocknr (%llu)",
 207                             (unsigned long long)group_blkno,
 208                             (unsigned long long) bg_bh->b_blocknr);
 209                 status = -EIO;
 210                 goto bail;
 211         }
 212
 213         status = ocfs2_journal_access(handle,
 214                                       alloc_inode,
 215                                       bg_bh,
 216                                       OCFS2_JOURNAL_ACCESS_CREATE);
 217         if (status < 0) {
 218                 mlog_errno(status);
 219                 goto bail;
 220         }
 221
 222         memset(bg, 0, sb->s_blocksize);
 223         strcpy(bg->bg_signature, OCFS2_GROUP_DESC_SIGNATURE);
 224         bg->bg_generation = cpu_to_le32(OCFS2_SB(sb)->fs_generation);
 225         bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb));
 226         bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
 227         bg->bg_chain = cpu_to_le16(my_chain);
 228         bg->bg_next_group = cl->cl_recs[my_chain].c_blkno;
 229         bg->bg_parent_dinode = cpu_to_le64(OCFS2_I(alloc_inode)->ip_blkno);
 230         bg->bg_blkno = cpu_to_le64(group_blkno);
 231         /* set the 1st bit in the bitmap to account for the descriptor block */
 232         ocfs2_set_bit(0, (unsigned long *)bg->bg_bitmap);
 233         bg->bg_free_bits_count = cpu_to_le16(le16_to_cpu(bg->bg_bits) - 1);
 234
 235         status = ocfs2_journal_dirty(handle, bg_bh);
 236         if (status < 0)
 237                 mlog_errno(status);
 238
 239         /* There is no need to zero out or otherwise initialize the
 240          * other blocks in a group - All valid FS metadata in a block
 241          * group stores the superblock fs_generation value at
 242          * allocation time. */
 243
 244 bail:
 245         mlog_exit(status);
 246         return status;
 247 }
 248
 249 static inline u16 ocfs2_find_smallest_chain(struct ocfs2_chain_list *cl)
 250 {
 251         u16 curr, best;
 252
 253         best = curr = 0;
 254         while (curr < le16_to_cpu(cl->cl_count)) {
 255                 if (le32_to_cpu(cl->cl_recs[best].c_total) >
 256                     le32_to_cpu(cl->cl_recs[curr].c_total))
 257                         best = curr;
 258                 curr++;
 259         }
 260         return best;
 261 }
 262
 263 /*
 264  * We expect the block group allocator to already be locked.
 265  */
 266 static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
 267                                    struct inode *alloc_inode,
 268                                    struct buffer_head *bh)
 269 {
 270         int status, credits;
 271         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) bh->b_data;
 272         struct ocfs2_chain_list *cl;
 273         struct ocfs2_alloc_context *ac = NULL;
 274         handle_t *handle = NULL;
 275         u32 bit_off, num_bits;
 276         u16 alloc_rec;
 277         u64 bg_blkno;
 278         struct buffer_head *bg_bh = NULL;
 279         struct ocfs2_group_desc *bg;
 280
 281         BUG_ON(ocfs2_is_cluster_bitmap(alloc_inode));
 282
 283         mlog_entry_void();
 284
 285         cl = &fe->id2.i_chain;
 286         status = ocfs2_reserve_clusters(osb,
 287                                         le16_to_cpu(cl->cl_cpg),
 288                                         &ac);
 289         if (status < 0) {
 290                 if (status != -ENOSPC)
 291                         mlog_errno(status);
 292                 goto bail;
 293         }
 294
 295         credits = ocfs2_calc_group_alloc_credits(osb->sb,
 296                                                  le16_to_cpu(cl->cl_cpg));
 297         handle = ocfs2_start_trans(osb, credits);
 298         if (IS_ERR(handle)) {
 299                 status = PTR_ERR(handle);
 300                 handle = NULL;
 301                 mlog_errno(status);
 302                 goto bail;
 303         }
 304
 305         status = ocfs2_claim_clusters(osb,
 306                                       handle,
 307                                       ac,
 308                                       le16_to_cpu(cl->cl_cpg),
 309                                       &bit_off,
 310                                       &num_bits);
 311         if (status < 0) {
 312                 if (status != -ENOSPC)
 313                         mlog_errno(status);
 314                 goto bail;
 315         }
 316
 317         alloc_rec = ocfs2_find_smallest_chain(cl);
 318
 319         /* setup the group */
 320         bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 321         mlog(0, "new descriptor, record %u, at block %llu\n",
 322              alloc_rec, (unsigned long long)bg_blkno);
 323
 324         bg_bh = sb_getblk(osb->sb, bg_blkno);
 325         if (!bg_bh) {
 326                 status = -EIO;
 327                 mlog_errno(status);
 328                 goto bail;
 329         }
 330         ocfs2_set_new_buffer_uptodate(alloc_inode, bg_bh);
 331
 332         status = ocfs2_block_group_fill(handle,
 333                                         alloc_inode,
 334                                         bg_bh,
 335                                         bg_blkno,
 336                                         alloc_rec,
 337                                         cl);
 338         if (status < 0) {
 339                 mlog_errno(status);
 340                 goto bail;
 341         }
 342
 343         bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 344
 345         status = ocfs2_journal_access(handle, alloc_inode,
 346                                       bh, OCFS2_JOURNAL_ACCESS_WRITE);
 347         if (status < 0) {
 348                 mlog_errno(status);
 349                 goto bail;
 350         }
 351
 352         le32_add_cpu(&cl->cl_recs[alloc_rec].c_free,
 353                      le16_to_cpu(bg->bg_free_bits_count));
 354         le32_add_cpu(&cl->cl_recs[alloc_rec].c_total, le16_to_cpu(bg->bg_bits));
 355         cl->cl_recs[alloc_rec].c_blkno  = cpu_to_le64(bg_blkno);
 356         if (le16_to_cpu(cl->cl_next_free_rec) < le16_to_cpu(cl->cl_count))
 357                 le16_add_cpu(&cl->cl_next_free_rec, 1);
 358
 359         le32_add_cpu(&fe->id1.bitmap1.i_used, le16_to_cpu(bg->bg_bits) -
 360                                         le16_to_cpu(bg->bg_free_bits_count));
 361         le32_add_cpu(&fe->id1.bitmap1.i_total, le16_to_cpu(bg->bg_bits));
 362         le32_add_cpu(&fe->i_clusters, le16_to_cpu(cl->cl_cpg));
 363
 364         status = ocfs2_journal_dirty(handle, bh);
 365         if (status < 0) {
 366                 mlog_errno(status);
 367                 goto bail;
 368         }
 369
 370         spin_lock(&OCFS2_I(alloc_inode)->ip_lock);
 371         OCFS2_I(alloc_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
 372         fe->i_size = cpu_to_le64(ocfs2_clusters_to_bytes(alloc_inode->i_sb,
 373                                              le32_to_cpu(fe->i_clusters)));
 374         spin_unlock(&OCFS2_I(alloc_inode)->ip_lock);
 375         i_size_write(alloc_inode, le64_to_cpu(fe->i_size));
 376         alloc_inode->i_blocks = ocfs2_inode_sector_count(alloc_inode);
 377
 378         status = 0;
 379 bail:
 380         if (handle)
 381                 ocfs2_commit_trans(osb, handle);
 382
 383         if (ac)
 384                 ocfs2_free_alloc_context(ac);
 385
 386         if (bg_bh)
 387                 brelse(bg_bh);
 388
 389         mlog_exit(status);
 390         return status;
 391 }
 392
 393 static int ocfs2_reserve_suballoc_bits(struct ocfs2_super *osb,
 394                                        struct ocfs2_alloc_context *ac,
 395                                        int type,
 396                                        u32 slot)
 397 {
 398         int status;
 399         u32 bits_wanted = ac->ac_bits_wanted;
 400         struct inode *alloc_inode;
 401         struct buffer_head *bh = NULL;
 402         struct ocfs2_dinode *fe;
 403         u32 free_bits;
 404
 405         mlog_entry_void();
 406
 407         alloc_inode = ocfs2_get_system_file_inode(osb, type, slot);
 408         if (!alloc_inode) {
 409                 mlog_errno(-EINVAL);
 410                 return -EINVAL;
 411         }
 412
 413         mutex_lock(&alloc_inode->i_mutex);
 414
 415         status = ocfs2_meta_lock(alloc_inode, &bh, 1);
 416         if (status < 0) {
 417                 mutex_unlock(&alloc_inode->i_mutex);
 418                 iput(alloc_inode);
 419
 420                 mlog_errno(status);
 421                 return status;
 422         }
 423
 424         ac->ac_inode = alloc_inode;
 425
 426         fe = (struct ocfs2_dinode *) bh->b_data;
 427         if (!OCFS2_IS_VALID_DINODE(fe)) {
 428                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
 429                 status = -EIO;
 430                 goto bail;
 431         }
 432         if (!(fe->i_flags & cpu_to_le32(OCFS2_CHAIN_FL))) {
 433                 ocfs2_error(alloc_inode->i_sb, "Invalid chain allocator %llu",
 434                             (unsigned long long)le64_to_cpu(fe->i_blkno));
 435                 status = -EIO;
 436                 goto bail;
 437         }
 438
 439         free_bits = le32_to_cpu(fe->id1.bitmap1.i_total) -
 440                 le32_to_cpu(fe->id1.bitmap1.i_used);
 441
 442         if (bits_wanted > free_bits) {
 443                 /* cluster bitmap never grows */
 444                 if (ocfs2_is_cluster_bitmap(alloc_inode)) {
 445                         mlog(0, "Disk Full: wanted=%u, free_bits=%u\n",
 446                              bits_wanted, free_bits);
 447                         status = -ENOSPC;
 448                         goto bail;
 449                 }
 450
 451                 status = ocfs2_block_group_alloc(osb, alloc_inode, bh);
 452                 if (status < 0) {
 453                         if (status != -ENOSPC)
 454                                 mlog_errno(status);
 455                         goto bail;
 456                 }
 457                 atomic_inc(&osb->alloc_stats.bg_extends);
 458
 459                 /* You should never ask for this much metadata */
 460                 BUG_ON(bits_wanted >
 461                        (le32_to_cpu(fe->id1.bitmap1.i_total)
 462                         - le32_to_cpu(fe->id1.bitmap1.i_used)));
 463         }
 464
 465         get_bh(bh);
 466         ac->ac_bh = bh;
 467 bail:
 468         if (bh)
 469                 brelse(bh);
 470
 471         mlog_exit(status);
 472         return status;
 473 }
 474
 475 int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
 476                                struct ocfs2_dinode *fe,
 477                                struct ocfs2_alloc_context **ac)
 478 {
 479         int status;
 480         u32 slot;
 481
 482         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 483         if (!(*ac)) {
 484                 status = -ENOMEM;
 485                 mlog_errno(status);
 486                 goto bail;
 487         }
 488
 489         (*ac)->ac_bits_wanted = ocfs2_extend_meta_needed(fe);
 490         (*ac)->ac_which = OCFS2_AC_USE_META;
 491
 492 #ifndef OCFS2_USE_ALL_METADATA_SUBALLOCATORS
 493         slot = 0;
 494 #else
 495         slot = osb->slot_num;
 496 #endif
 497
 498         (*ac)->ac_group_search = ocfs2_block_group_search;
 499
 500         status = ocfs2_reserve_suballoc_bits(osb, (*ac),
 501                                              EXTENT_ALLOC_SYSTEM_INODE, slot);
 502         if (status < 0) {
 503                 if (status != -ENOSPC)
 504                         mlog_errno(status);
 505                 goto bail;
 506         }
 507
 508         status = 0;
 509 bail:
 510         if ((status < 0) && *ac) {
 511                 ocfs2_free_alloc_context(*ac);
 512                 *ac = NULL;
 513         }
 514
 515         mlog_exit(status);
 516         return status;
 517 }
 518
 519 int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
 520                             struct ocfs2_alloc_context **ac)
 521 {
 522         int status;
 523
 524         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 525         if (!(*ac)) {
 526                 status = -ENOMEM;
 527                 mlog_errno(status);
 528                 goto bail;
 529         }
 530
 531         (*ac)->ac_bits_wanted = 1;
 532         (*ac)->ac_which = OCFS2_AC_USE_INODE;
 533
 534         (*ac)->ac_group_search = ocfs2_block_group_search;
 535
 536         status = ocfs2_reserve_suballoc_bits(osb, *ac,
 537                                              INODE_ALLOC_SYSTEM_INODE,
 538                                              osb->slot_num);
 539         if (status < 0) {
 540                 if (status != -ENOSPC)
 541                         mlog_errno(status);
 542                 goto bail;
 543         }
 544
 545         status = 0;
 546 bail:
 547         if ((status < 0) && *ac) {
 548                 ocfs2_free_alloc_context(*ac);
 549                 *ac = NULL;
 550         }
 551
 552         mlog_exit(status);
 553         return status;
 554 }
 555
 556 /* local alloc code has to do the same thing, so rather than do this
 557  * twice.. */
 558 int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
 559                                       struct ocfs2_alloc_context *ac)
 560 {
 561         int status;
 562
 563         ac->ac_which = OCFS2_AC_USE_MAIN;
 564         ac->ac_group_search = ocfs2_cluster_group_search;
 565
 566         status = ocfs2_reserve_suballoc_bits(osb, ac,
 567                                              GLOBAL_BITMAP_SYSTEM_INODE,
 568                                              OCFS2_INVALID_SLOT);
 569         if (status < 0 && status != -ENOSPC) {
 570                 mlog_errno(status);
 571                 goto bail;
 572         }
 573
 574 bail:
 575         return status;
 576 }
 577
 578 /* Callers don't need to care which bitmap (local alloc or main) to
 579  * use so we figure it out for them, but unfortunately this clutters
 580  * things a bit. */
 581 int ocfs2_reserve_clusters(struct ocfs2_super *osb,
 582                            u32 bits_wanted,
 583                            struct ocfs2_alloc_context **ac)
 584 {
 585         int status;
 586
 587         mlog_entry_void();
 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 = bits_wanted;
 597
 598         status = -ENOSPC;
 599         if (ocfs2_alloc_should_use_local(osb, bits_wanted)) {
 600                 status = ocfs2_reserve_local_alloc_bits(osb,
 601                                                         bits_wanted,
 602                                                         *ac);
 603                 if ((status < 0) && (status != -ENOSPC)) {
 604                         mlog_errno(status);
 605                         goto bail;
 606                 } else if (status == -ENOSPC) {
 607                         /* reserve_local_bits will return enospc with
 608                          * the local alloc inode still locked, so we
 609                          * can change this safely here. */
 610                         mlog(0, "Disabling local alloc\n");
 611                         /* We set to OCFS2_LA_DISABLED so that umount
 612                          * can clean up what's left of the local
 613                          * allocation */
 614                         osb->local_alloc_state = OCFS2_LA_DISABLED;
 615                 }
 616         }
 617
 618         if (status == -ENOSPC) {
 619                 status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
 620                 if (status < 0) {
 621                         if (status != -ENOSPC)
 622                                 mlog_errno(status);
 623                         goto bail;
 624                 }
 625         }
 626
 627         status = 0;
 628 bail:
 629         if ((status < 0) && *ac) {
 630                 ocfs2_free_alloc_context(*ac);
 631                 *ac = NULL;
 632         }
 633
 634         mlog_exit(status);
 635         return status;
 636 }
 637
 638 /*
 639  * More or less lifted from ext3. I'll leave their description below:
 640  *
 641  * "For ext3 allocations, we must not reuse any blocks which are
 642  * allocated in the bitmap buffer's "last committed data" copy.  This
 643  * prevents deletes from freeing up the page for reuse until we have
 644  * committed the delete transaction.
 645  *
 646  * If we didn't do this, then deleting something and reallocating it as
 647  * data would allow the old block to be overwritten before the
 648  * transaction committed (because we force data to disk before commit).
 649  * This would lead to corruption if we crashed between overwriting the
 650  * data and committing the delete.
 651  *
 652  * @@@ We may want to make this allocation behaviour conditional on
 653  * data-writes at some point, and disable it for metadata allocations or
 654  * sync-data inodes."
 655  *
 656  * Note: OCFS2 already does this differently for metadata vs data
 657  * allocations, as those bitmaps are seperate and undo access is never
 658  * called on a metadata group descriptor.
 659  */
 660 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
 661                                          int nr)
 662 {
 663         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 664
 665         if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
 666                 return 0;
 667         if (!buffer_jbd(bg_bh) || !bh2jh(bg_bh)->b_committed_data)
 668                 return 1;
 669
 670         bg = (struct ocfs2_group_desc *) bh2jh(bg_bh)->b_committed_data;
 671         return !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
 672 }
 673
 674 static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
 675                                              struct buffer_head *bg_bh,
 676                                              unsigned int bits_wanted,
 677                                              unsigned int total_bits,
 678                                              u16 *bit_off,
 679                                              u16 *bits_found)
 680 {
 681         void *bitmap;
 682         u16 best_offset, best_size;
 683         int offset, start, found, status = 0;
 684         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 685
 686         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
 687                 OCFS2_RO_ON_INVALID_GROUP_DESC(osb->sb, bg);
 688                 return -EIO;
 689         }
 690
 691         found = start = best_offset = best_size = 0;
 692         bitmap = bg->bg_bitmap;
 693
 694         while((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) != -1) {
 695                 if (offset == total_bits)
 696                         break;
 697
 698                 if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
 699                         /* We found a zero, but we can't use it as it
 700                          * hasn't been put to disk yet! */
 701                         found = 0;
 702                         start = offset + 1;
 703                 } else if (offset == start) {
 704                         /* we found a zero */
 705                         found++;
 706                         /* move start to the next bit to test */
 707                         start++;
 708                 } else {
 709                         /* got a zero after some ones */
 710                         found = 1;
 711                         start = offset + 1;
 712                 }
 713                 if (found > best_size) {
 714                         best_size = found;
 715                         best_offset = start - found;
 716                 }
 717                 /* we got everything we needed */
 718                 if (found == bits_wanted) {
 719                         /* mlog(0, "Found it all!\n"); */
 720                         break;
 721                 }
 722         }
 723
 724         /* XXX: I think the first clause is equivalent to the second
 725          *      - jlbec */
 726         if (found == bits_wanted) {
 727                 *bit_off = start - found;
 728                 *bits_found = found;
 729         } else if (best_size) {
 730                 *bit_off = best_offset;
 731                 *bits_found = best_size;
 732         } else {
 733                 status = -ENOSPC;
 734                 /* No error log here -- see the comment above
 735                  * ocfs2_test_bg_bit_allocatable */
 736         }
 737
 738         return status;
 739 }
 740
 741 static inline int ocfs2_block_group_set_bits(handle_t *handle,
 742                                              struct inode *alloc_inode,
 743                                              struct ocfs2_group_desc *bg,
 744                                              struct buffer_head *group_bh,
 745                                              unsigned int bit_off,
 746                                              unsigned int num_bits)
 747 {
 748         int status;
 749         void *bitmap = bg->bg_bitmap;
 750         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
 751
 752         mlog_entry_void();
 753
 754         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
 755                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
 756                 status = -EIO;
 757                 goto bail;
 758         }
 759         BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
 760
 761         mlog(0, "block_group_set_bits: off = %u, num = %u\n", bit_off,
 762              num_bits);
 763
 764         if (ocfs2_is_cluster_bitmap(alloc_inode))
 765                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
 766
 767         status = ocfs2_journal_access(handle,
 768                                       alloc_inode,
 769                                       group_bh,
 770                                       journal_type);
 771         if (status < 0) {
 772                 mlog_errno(status);
 773                 goto bail;
 774         }
 775
 776         le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
 777
 778         while(num_bits--)
 779                 ocfs2_set_bit(bit_off++, bitmap);
 780
 781         status = ocfs2_journal_dirty(handle,
 782                                      group_bh);
 783         if (status < 0) {
 784                 mlog_errno(status);
 785                 goto bail;
 786         }
 787
 788 bail:
 789         mlog_exit(status);
 790         return status;
 791 }
 792
 793 /* find the one with the most empty bits */
 794 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
 795 {
 796         u16 curr, best;
 797
 798         BUG_ON(!cl->cl_next_free_rec);
 799
 800         best = curr = 0;
 801         while (curr < le16_to_cpu(cl->cl_next_free_rec)) {
 802                 if (le32_to_cpu(cl->cl_recs[curr].c_free) >
 803                     le32_to_cpu(cl->cl_recs[best].c_free))
 804                         best = curr;
 805                 curr++;
 806         }
 807
 808         BUG_ON(best >= le16_to_cpu(cl->cl_next_free_rec));
 809         return best;
 810 }
 811
 812 static int ocfs2_relink_block_group(handle_t *handle,
 813                                     struct inode *alloc_inode,
 814                                     struct buffer_head *fe_bh,
 815                                     struct buffer_head *bg_bh,
 816                                     struct buffer_head *prev_bg_bh,
 817                                     u16 chain)
 818 {
 819         int status;
 820         /* there is a really tiny chance the journal calls could fail,
 821          * but we wouldn't want inconsistent blocks in *any* case. */
 822         u64 fe_ptr, bg_ptr, prev_bg_ptr;
 823         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
 824         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 825         struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
 826
 827         if (!OCFS2_IS_VALID_DINODE(fe)) {
 828                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
 829                 status = -EIO;
 830                 goto out;
 831         }
 832         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
 833                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
 834                 status = -EIO;
 835                 goto out;
 836         }
 837         if (!OCFS2_IS_VALID_GROUP_DESC(prev_bg)) {
 838                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, prev_bg);
 839                 status = -EIO;
 840                 goto out;
 841         }
 842
 843         mlog(0, "Suballoc %llu, chain %u, move group %llu to top, prev = %llu\n",
 844              (unsigned long long)le64_to_cpu(fe->i_blkno), chain,
 845              (unsigned long long)le64_to_cpu(bg->bg_blkno),
 846              (unsigned long long)le64_to_cpu(prev_bg->bg_blkno));
 847
 848         fe_ptr = le64_to_cpu(fe->id2.i_chain.cl_recs[chain].c_blkno);
 849         bg_ptr = le64_to_cpu(bg->bg_next_group);
 850         prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
 851
 852         status = ocfs2_journal_access(handle, alloc_inode, prev_bg_bh,
 853                                       OCFS2_JOURNAL_ACCESS_WRITE);
 854         if (status < 0) {
 855                 mlog_errno(status);
 856                 goto out_rollback;
 857         }
 858
 859         prev_bg->bg_next_group = bg->bg_next_group;
 860
 861         status = ocfs2_journal_dirty(handle, prev_bg_bh);
 862         if (status < 0) {
 863                 mlog_errno(status);
 864                 goto out_rollback;
 865         }
 866
 867         status = ocfs2_journal_access(handle, alloc_inode, bg_bh,
 868                                       OCFS2_JOURNAL_ACCESS_WRITE);
 869         if (status < 0) {
 870                 mlog_errno(status);
 871                 goto out_rollback;
 872         }
 873
 874         bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
 875
 876         status = ocfs2_journal_dirty(handle, bg_bh);
 877         if (status < 0) {
 878                 mlog_errno(status);
 879                 goto out_rollback;
 880         }
 881
 882         status = ocfs2_journal_access(handle, alloc_inode, fe_bh,
 883                                       OCFS2_JOURNAL_ACCESS_WRITE);
 884         if (status < 0) {
 885                 mlog_errno(status);
 886                 goto out_rollback;
 887         }
 888
 889         fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
 890
 891         status = ocfs2_journal_dirty(handle, fe_bh);
 892         if (status < 0) {
 893                 mlog_errno(status);
 894                 goto out_rollback;
 895         }
 896
 897         status = 0;
 898 out_rollback:
 899         if (status < 0) {
 900                 fe->id2.i_chain.cl_recs[chain].c_blkno = cpu_to_le64(fe_ptr);
 901                 bg->bg_next_group = cpu_to_le64(bg_ptr);
 902                 prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
 903         }
 904 out:
 905         mlog_exit(status);
 906         return status;
 907 }
 908
 909 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
 910                                                      u32 wanted)
 911 {
 912         return le16_to_cpu(bg->bg_free_bits_count) > wanted;
 913 }
 914
 915 /* return 0 on success, -ENOSPC to keep searching and any other < 0
 916  * value on error. */
 917 static int ocfs2_cluster_group_search(struct inode *inode,
 918                                       struct buffer_head *group_bh,
 919                                       u32 bits_wanted, u32 min_bits,
 920                                       u16 *bit_off, u16 *bits_found)
 921 {
 922         int search = -ENOSPC;
 923         int ret;
 924         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
 925         u16 tmp_off, tmp_found;
 926         unsigned int max_bits, gd_cluster_off;
 927
 928         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
 929
 930         if (gd->bg_free_bits_count) {
 931                 max_bits = le16_to_cpu(gd->bg_bits);
 932
 933                 /* Tail groups in cluster bitmaps which aren't cpg
 934                  * aligned are prone to partial extention by a failed
 935                  * fs resize. If the file system resize never got to
 936                  * update the dinode cluster count, then we don't want
 937                  * to trust any clusters past it, regardless of what
 938                  * the group descriptor says. */
 939                 gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
 940                                                           le64_to_cpu(gd->bg_blkno));
 941                 if ((gd_cluster_off + max_bits) >
 942                     OCFS2_I(inode)->ip_clusters) {
 943                         max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
 944                         mlog(0, "Desc %llu, bg_bits %u, clusters %u, use %u\n",
 945                              (unsigned long long)le64_to_cpu(gd->bg_blkno),
 946                              le16_to_cpu(gd->bg_bits),
 947                              OCFS2_I(inode)->ip_clusters, max_bits);
 948                 }
 949
 950                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
 951                                                         group_bh, bits_wanted,
 952                                                         max_bits,
 953                                                         &tmp_off, &tmp_found);
 954                 if (ret)
 955                         return ret;
 956
 957                 /* ocfs2_block_group_find_clear_bits() might
 958                  * return success, but we still want to return
 959                  * -ENOSPC unless it found the minimum number
 960                  * of bits. */
 961                 if (min_bits <= tmp_found) {
 962                         *bit_off = tmp_off;
 963                         *bits_found = tmp_found;
 964                         search = 0; /* success */
 965                 }
 966         }
 967
 968         return search;
 969 }
 970
 971 static int ocfs2_block_group_search(struct inode *inode,
 972                                     struct buffer_head *group_bh,
 973                                     u32 bits_wanted, u32 min_bits,
 974                                     u16 *bit_off, u16 *bits_found)
 975 {
 976         int ret = -ENOSPC;
 977         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
 978
 979         BUG_ON(min_bits != 1);
 980         BUG_ON(ocfs2_is_cluster_bitmap(inode));
 981
 982         if (bg->bg_free_bits_count)
 983                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
 984                                                         group_bh, bits_wanted,
 985                                                         le16_to_cpu(bg->bg_bits),
 986                                                         bit_off, bits_found);
 987
 988         return ret;
 989 }
 990
 991 static int ocfs2_alloc_dinode_update_counts(struct inode *inode,
 992                                        handle_t *handle,
 993                                        struct buffer_head *di_bh,
 994                                        u32 num_bits,
 995                                        u16 chain)
 996 {
 997         int ret;
 998         u32 tmp_used;
 999         struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1000         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &di->id2.i_chain;
1001
1002         ret = ocfs2_journal_access(handle, inode, di_bh,
1003                                    OCFS2_JOURNAL_ACCESS_WRITE);
1004         if (ret < 0) {
1005                 mlog_errno(ret);
1006                 goto out;
1007         }
1008
1009         tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1010         di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
1011         le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
1012
1013         ret = ocfs2_journal_dirty(handle, di_bh);
1014         if (ret < 0)
1015                 mlog_errno(ret);
1016
1017 out:
1018         return ret;
1019 }
1020
1021 static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
1022                                   handle_t *handle,
1023                                   u32 bits_wanted,
1024                                   u32 min_bits,
1025                                   u16 *bit_off,
1026                                   unsigned int *num_bits,
1027                                   u64 gd_blkno,
1028                                   u16 *bits_left)
1029 {
1030         int ret;
1031         u16 found;
1032         struct buffer_head *group_bh = NULL;
1033         struct ocfs2_group_desc *gd;
1034         struct inode *alloc_inode = ac->ac_inode;
1035
1036         ret = ocfs2_read_block(OCFS2_SB(alloc_inode->i_sb), gd_blkno,
1037                                &group_bh, OCFS2_BH_CACHED, alloc_inode);
1038         if (ret < 0) {
1039                 mlog_errno(ret);
1040                 return ret;
1041         }
1042
1043         gd = (struct ocfs2_group_desc *) group_bh->b_data;
1044         if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
1045                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, gd);
1046                 ret = -EIO;
1047                 goto out;
1048         }
1049
1050         ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
1051                                   bit_off, &found);
1052         if (ret < 0) {
1053                 if (ret != -ENOSPC)
1054                         mlog_errno(ret);
1055                 goto out;
1056         }
1057
1058         *num_bits = found;
1059
1060         ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
1061                                                *num_bits,
1062                                                le16_to_cpu(gd->bg_chain));
1063         if (ret < 0) {
1064                 mlog_errno(ret);
1065                 goto out;
1066         }
1067
1068         ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
1069                                          *bit_off, *num_bits);
1070         if (ret < 0)
1071                 mlog_errno(ret);
1072
1073         *bits_left = le16_to_cpu(gd->bg_free_bits_count);
1074
1075 out:
1076         brelse(group_bh);
1077
1078         return ret;
1079 }
1080
1081 static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
1082                               handle_t *handle,
1083                               u32 bits_wanted,
1084                               u32 min_bits,
1085                               u16 *bit_off,
1086                               unsigned int *num_bits,
1087                               u64 *bg_blkno,
1088                               u16 *bits_left)
1089 {
1090         int status;
1091         u16 chain, tmp_bits;
1092         u32 tmp_used;
1093         u64 next_group;
1094         struct inode *alloc_inode = ac->ac_inode;
1095         struct buffer_head *group_bh = NULL;
1096         struct buffer_head *prev_group_bh = NULL;
1097         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1098         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1099         struct ocfs2_group_desc *bg;
1100
1101         chain = ac->ac_chain;
1102         mlog(0, "trying to alloc %u bits from chain %u, inode %llu\n",
1103              bits_wanted, chain,
1104              (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno);
1105
1106         status = ocfs2_read_block(OCFS2_SB(alloc_inode->i_sb),
1107                                   le64_to_cpu(cl->cl_recs[chain].c_blkno),
1108                                   &group_bh, OCFS2_BH_CACHED, alloc_inode);
1109         if (status < 0) {
1110                 mlog_errno(status);
1111                 goto bail;
1112         }
1113         bg = (struct ocfs2_group_desc *) group_bh->b_data;
1114         status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, bg);
1115         if (status) {
1116                 mlog_errno(status);
1117                 goto bail;
1118         }
1119
1120         status = -ENOSPC;
1121         /* for now, the chain search is a bit simplistic. We just use
1122          * the 1st group with any empty bits. */
1123         while ((status = ac->ac_group_search(alloc_inode, group_bh,
1124                                              bits_wanted, min_bits, bit_off,
1125                                              &tmp_bits)) == -ENOSPC) {
1126                 if (!bg->bg_next_group)
1127                         break;
1128
1129                 if (prev_group_bh) {
1130                         brelse(prev_group_bh);
1131                         prev_group_bh = NULL;
1132                 }
1133                 next_group = le64_to_cpu(bg->bg_next_group);
1134                 prev_group_bh = group_bh;
1135                 group_bh = NULL;
1136                 status = ocfs2_read_block(OCFS2_SB(alloc_inode->i_sb),
1137                                           next_group, &group_bh,
1138                                           OCFS2_BH_CACHED, alloc_inode);
1139                 if (status < 0) {
1140                         mlog_errno(status);
1141                         goto bail;
1142                 }
1143                 bg = (struct ocfs2_group_desc *) group_bh->b_data;
1144                 status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, bg);
1145                 if (status) {
1146                         mlog_errno(status);
1147                         goto bail;
1148                 }
1149         }
1150         if (status < 0) {
1151                 if (status != -ENOSPC)
1152                         mlog_errno(status);
1153                 goto bail;
1154         }
1155
1156         mlog(0, "alloc succeeds: we give %u bits from block group %llu\n",
1157              tmp_bits, (unsigned long long)le64_to_cpu(bg->bg_blkno));
1158
1159         *num_bits = tmp_bits;
1160
1161         BUG_ON(*num_bits == 0);
1162
1163         /*
1164          * Keep track of previous block descriptor read. When
1165          * we find a target, if we have read more than X
1166          * number of descriptors, and the target is reasonably
1167          * empty, relink him to top of his chain.
1168          *
1169          * We've read 0 extra blocks and only send one more to
1170          * the transaction, yet the next guy to search has a
1171          * much easier time.
1172          *
1173          * Do this *after* figuring out how many bits we're taking out
1174          * of our target group.
1175          */
1176         if (ac->ac_allow_chain_relink &&
1177             (prev_group_bh) &&
1178             (ocfs2_block_group_reasonably_empty(bg, *num_bits))) {
1179                 status = ocfs2_relink_block_group(handle, alloc_inode,
1180                                                   ac->ac_bh, group_bh,
1181                                                   prev_group_bh, chain);
1182                 if (status < 0) {
1183                         mlog_errno(status);
1184                         goto bail;
1185                 }
1186         }
1187
1188         /* Ok, claim our bits now: set the info on dinode, chainlist
1189          * and then the group */
1190         status = ocfs2_journal_access(handle,
1191                                       alloc_inode,
1192                                       ac->ac_bh,
1193                                       OCFS2_JOURNAL_ACCESS_WRITE);
1194         if (status < 0) {
1195                 mlog_errno(status);
1196                 goto bail;
1197         }
1198
1199         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
1200         fe->id1.bitmap1.i_used = cpu_to_le32(*num_bits + tmp_used);
1201         le32_add_cpu(&cl->cl_recs[chain].c_free, -(*num_bits));
1202
1203         status = ocfs2_journal_dirty(handle,
1204                                      ac->ac_bh);
1205         if (status < 0) {
1206                 mlog_errno(status);
1207                 goto bail;
1208         }
1209
1210         status = ocfs2_block_group_set_bits(handle,
1211                                             alloc_inode,
1212                                             bg,
1213                                             group_bh,
1214                                             *bit_off,
1215                                             *num_bits);
1216         if (status < 0) {
1217                 mlog_errno(status);
1218                 goto bail;
1219         }
1220
1221         mlog(0, "Allocated %u bits from suballocator %llu\n", *num_bits,
1222              (unsigned long long)le64_to_cpu(fe->i_blkno));
1223
1224         *bg_blkno = le64_to_cpu(bg->bg_blkno);
1225         *bits_left = le16_to_cpu(bg->bg_free_bits_count);
1226 bail:
1227         if (group_bh)
1228                 brelse(group_bh);
1229         if (prev_group_bh)
1230                 brelse(prev_group_bh);
1231
1232         mlog_exit(status);
1233         return status;
1234 }
1235
1236 /* will give out up to bits_wanted contiguous bits. */
1237 static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
1238                                      struct ocfs2_alloc_context *ac,
1239                                      handle_t *handle,
1240                                      u32 bits_wanted,
1241                                      u32 min_bits,
1242                                      u16 *bit_off,
1243                                      unsigned int *num_bits,
1244                                      u64 *bg_blkno)
1245 {
1246         int status;
1247         u16 victim, i;
1248         u16 bits_left = 0;
1249         u64 hint_blkno = ac->ac_last_group;
1250         struct ocfs2_chain_list *cl;
1251         struct ocfs2_dinode *fe;
1252
1253         mlog_entry_void();
1254
1255         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1256         BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1257         BUG_ON(!ac->ac_bh);
1258
1259         fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1260         if (!OCFS2_IS_VALID_DINODE(fe)) {
1261                 OCFS2_RO_ON_INVALID_DINODE(osb->sb, fe);
1262                 status = -EIO;
1263                 goto bail;
1264         }
1265         if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1266             le32_to_cpu(fe->id1.bitmap1.i_total)) {
1267                 ocfs2_error(osb->sb, "Chain allocator dinode %llu has %u used "
1268                             "bits but only %u total.",
1269                             (unsigned long long)le64_to_cpu(fe->i_blkno),
1270                             le32_to_cpu(fe->id1.bitmap1.i_used),
1271                             le32_to_cpu(fe->id1.bitmap1.i_total));
1272                 status = -EIO;
1273                 goto bail;
1274         }
1275
1276         if (hint_blkno) {
1277                 /* Attempt to short-circuit the usual search mechanism
1278                  * by jumping straight to the most recently used
1279                  * allocation group. This helps us mantain some
1280                  * contiguousness across allocations. */
1281                 status = ocfs2_search_one_group(ac, handle, bits_wanted,
1282                                                 min_bits, bit_off, num_bits,
1283                                                 hint_blkno, &bits_left);
1284                 if (!status) {
1285                         /* Be careful to update *bg_blkno here as the
1286                          * caller is expecting it to be filled in, and
1287                          * ocfs2_search_one_group() won't do that for
1288                          * us. */
1289                         *bg_blkno = hint_blkno;
1290                         goto set_hint;
1291                 }
1292                 if (status < 0 && status != -ENOSPC) {
1293                         mlog_errno(status);
1294                         goto bail;
1295                 }
1296         }
1297
1298         cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1299
1300         victim = ocfs2_find_victim_chain(cl);
1301         ac->ac_chain = victim;
1302         ac->ac_allow_chain_relink = 1;
1303
1304         status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits, bit_off,
1305                                     num_bits, bg_blkno, &bits_left);
1306         if (!status)
1307                 goto set_hint;
1308         if (status < 0 && status != -ENOSPC) {
1309                 mlog_errno(status);
1310                 goto bail;
1311         }
1312
1313         mlog(0, "Search of victim chain %u came up with nothing, "
1314              "trying all chains now.\n", victim);
1315
1316         /* If we didn't pick a good victim, then just default to
1317          * searching each chain in order. Don't allow chain relinking
1318          * because we only calculate enough journal credits for one
1319          * relink per alloc. */
1320         ac->ac_allow_chain_relink = 0;
1321         for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
1322                 if (i == victim)
1323                         continue;
1324                 if (!cl->cl_recs[i].c_free)
1325                         continue;
1326
1327                 ac->ac_chain = i;
1328                 status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1329                                             bit_off, num_bits, bg_blkno,
1330                                             &bits_left);
1331                 if (!status)
1332                         break;
1333                 if (status < 0 && status != -ENOSPC) {
1334                         mlog_errno(status);
1335                         goto bail;
1336                 }
1337         }
1338
1339 set_hint:
1340         if (status != -ENOSPC) {
1341                 /* If the next search of this group is not likely to
1342                  * yield a suitable extent, then we reset the last
1343                  * group hint so as to not waste a disk read */
1344                 if (bits_left < min_bits)
1345                         ac->ac_last_group = 0;
1346                 else
1347                         ac->ac_last_group = *bg_blkno;
1348         }
1349
1350 bail:
1351         mlog_exit(status);
1352         return status;
1353 }
1354
1355 int ocfs2_claim_metadata(struct ocfs2_super *osb,
1356                          handle_t *handle,
1357                          struct ocfs2_alloc_context *ac,
1358                          u32 bits_wanted,
1359                          u16 *suballoc_bit_start,
1360                          unsigned int *num_bits,
1361                          u64 *blkno_start)
1362 {
1363         int status;
1364         u64 bg_blkno;
1365
1366         BUG_ON(!ac);
1367         BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
1368         BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
1369
1370         status = ocfs2_claim_suballoc_bits(osb,
1371                                            ac,
1372                                            handle,
1373                                            bits_wanted,
1374                                            1,
1375                                            suballoc_bit_start,
1376                                            num_bits,
1377                                            &bg_blkno);
1378         if (status < 0) {
1379                 mlog_errno(status);
1380                 goto bail;
1381         }
1382         atomic_inc(&osb->alloc_stats.bg_allocs);
1383
1384         *blkno_start = bg_blkno + (u64) *suballoc_bit_start;
1385         ac->ac_bits_given += (*num_bits);
1386         status = 0;
1387 bail:
1388         mlog_exit(status);
1389         return status;
1390 }
1391
1392 int ocfs2_claim_new_inode(struct ocfs2_super *osb,
1393                           handle_t *handle,
1394                           struct ocfs2_alloc_context *ac,
1395                           u16 *suballoc_bit,
1396                           u64 *fe_blkno)
1397 {
1398         int status;
1399         unsigned int num_bits;
1400         u64 bg_blkno;
1401
1402         mlog_entry_void();
1403
1404         BUG_ON(!ac);
1405         BUG_ON(ac->ac_bits_given != 0);
1406         BUG_ON(ac->ac_bits_wanted != 1);
1407         BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
1408
1409         status = ocfs2_claim_suballoc_bits(osb,
1410                                            ac,
1411                                            handle,
1412                                            1,
1413                                            1,
1414                                            suballoc_bit,
1415                                            &num_bits,
1416                                            &bg_blkno);
1417         if (status < 0) {
1418                 mlog_errno(status);
1419                 goto bail;
1420         }
1421         atomic_inc(&osb->alloc_stats.bg_allocs);
1422
1423         BUG_ON(num_bits != 1);
1424
1425         *fe_blkno = bg_blkno + (u64) (*suballoc_bit);
1426         ac->ac_bits_given++;
1427         status = 0;
1428 bail:
1429         mlog_exit(status);
1430         return status;
1431 }
1432
1433 /* translate a group desc. blkno and it's bitmap offset into
1434  * disk cluster offset. */
1435 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
1436                                                    u64 bg_blkno,
1437                                                    u16 bg_bit_off)
1438 {
1439         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1440         u32 cluster = 0;
1441
1442         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1443
1444         if (bg_blkno != osb->first_cluster_group_blkno)
1445                 cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
1446         cluster += (u32) bg_bit_off;
1447         return cluster;
1448 }
1449
1450 /* given a cluster offset, calculate which block group it belongs to
1451  * and return that block offset. */
1452 static inline u64 ocfs2_which_cluster_group(struct inode *inode,
1453                                             u32 cluster)
1454 {
1455         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1456         u32 group_no;
1457
1458         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1459
1460         group_no = cluster / osb->bitmap_cpg;
1461         if (!group_no)
1462                 return osb->first_cluster_group_blkno;
1463         return ocfs2_clusters_to_blocks(inode->i_sb,
1464                                         group_no * osb->bitmap_cpg);
1465 }
1466
1467 /* given the block number of a cluster start, calculate which cluster
1468  * group and descriptor bitmap offset that corresponds to. */
1469 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
1470                                                 u64 data_blkno,
1471                                                 u64 *bg_blkno,
1472                                                 u16 *bg_bit_off)
1473 {
1474         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1475         u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
1476
1477         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1478
1479         *bg_blkno = ocfs2_which_cluster_group(inode,
1480                                               data_cluster);
1481
1482         if (*bg_blkno == osb->first_cluster_group_blkno)
1483                 *bg_bit_off = (u16) data_cluster;
1484         else
1485                 *bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
1486                                                              data_blkno - *bg_blkno);
1487 }
1488
1489 /*
1490  * min_bits - minimum contiguous chunk from this total allocation we
1491  * can handle. set to what we asked for originally for a full
1492  * contig. allocation, set to '1' to indicate we can deal with extents
1493  * of any size.
1494  */
1495 int ocfs2_claim_clusters(struct ocfs2_super *osb,
1496                          handle_t *handle,
1497                          struct ocfs2_alloc_context *ac,
1498                          u32 min_clusters,
1499                          u32 *cluster_start,
1500                          u32 *num_clusters)
1501 {
1502         int status;
1503         unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
1504         u64 bg_blkno = 0;
1505         u16 bg_bit_off;
1506
1507         mlog_entry_void();
1508
1509         BUG_ON(!ac);
1510         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1511
1512         BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
1513                && ac->ac_which != OCFS2_AC_USE_MAIN);
1514
1515         if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
1516                 status = ocfs2_claim_local_alloc_bits(osb,
1517                                                       handle,
1518                                                       ac,
1519                                                       bits_wanted,
1520                                                       cluster_start,
1521                                                       num_clusters);
1522                 if (!status)
1523                         atomic_inc(&osb->alloc_stats.local_data);
1524         } else {
1525                 if (min_clusters > (osb->bitmap_cpg - 1)) {
1526                         /* The only paths asking for contiguousness
1527                          * should know about this already. */
1528                         mlog(ML_ERROR, "minimum allocation requested exceeds "
1529                                        "group bitmap size!");
1530                         status = -ENOSPC;
1531                         goto bail;
1532                 }
1533                 /* clamp the current request down to a realistic size. */
1534                 if (bits_wanted > (osb->bitmap_cpg - 1))
1535                         bits_wanted = osb->bitmap_cpg - 1;
1536
1537                 status = ocfs2_claim_suballoc_bits(osb,
1538                                                    ac,
1539                                                    handle,
1540                                                    bits_wanted,
1541                                                    min_clusters,
1542                                                    &bg_bit_off,
1543                                                    num_clusters,
1544                                                    &bg_blkno);
1545                 if (!status) {
1546                         *cluster_start =
1547                                 ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
1548                                                                  bg_blkno,
1549                                                                  bg_bit_off);
1550                         atomic_inc(&osb->alloc_stats.bitmap_data);
1551                 }
1552         }
1553         if (status < 0) {
1554                 if (status != -ENOSPC)
1555                         mlog_errno(status);
1556                 goto bail;
1557         }
1558
1559         ac->ac_bits_given += *num_clusters;
1560
1561 bail:
1562         mlog_exit(status);
1563         return status;
1564 }
1565
1566 static inline int ocfs2_block_group_clear_bits(handle_t *handle,
1567                                                struct inode *alloc_inode,
1568                                                struct ocfs2_group_desc *bg,
1569                                                struct buffer_head *group_bh,
1570                                                unsigned int bit_off,
1571                                                unsigned int num_bits)
1572 {
1573         int status;
1574         unsigned int tmp;
1575         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1576         struct ocfs2_group_desc *undo_bg = NULL;
1577
1578         mlog_entry_void();
1579
1580         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
1581                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
1582                 status = -EIO;
1583                 goto bail;
1584         }
1585
1586         mlog(0, "off = %u, num = %u\n", bit_off, num_bits);
1587
1588         if (ocfs2_is_cluster_bitmap(alloc_inode))
1589                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1590
1591         status = ocfs2_journal_access(handle, alloc_inode, group_bh,
1592                                       journal_type);
1593         if (status < 0) {
1594                 mlog_errno(status);
1595                 goto bail;
1596         }
1597
1598         if (ocfs2_is_cluster_bitmap(alloc_inode))
1599                 undo_bg = (struct ocfs2_group_desc *) bh2jh(group_bh)->b_committed_data;
1600
1601         tmp = num_bits;
1602         while(tmp--) {
1603                 ocfs2_clear_bit((bit_off + tmp),
1604                                 (unsigned long *) bg->bg_bitmap);
1605                 if (ocfs2_is_cluster_bitmap(alloc_inode))
1606                         ocfs2_set_bit(bit_off + tmp,
1607                                       (unsigned long *) undo_bg->bg_bitmap);
1608         }
1609         le16_add_cpu(&bg->bg_free_bits_count, num_bits);
1610
1611         status = ocfs2_journal_dirty(handle, group_bh);
1612         if (status < 0)
1613                 mlog_errno(status);
1614 bail:
1615         return status;
1616 }
1617
1618 /*
1619  * expects the suballoc inode to already be locked.
1620  */
1621 int ocfs2_free_suballoc_bits(handle_t *handle,
1622                              struct inode *alloc_inode,
1623                              struct buffer_head *alloc_bh,
1624                              unsigned int start_bit,
1625                              u64 bg_blkno,
1626                              unsigned int count)
1627 {
1628         int status = 0;
1629         u32 tmp_used;
1630         struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
1631         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
1632         struct ocfs2_chain_list *cl = &fe->id2.i_chain;
1633         struct buffer_head *group_bh = NULL;
1634         struct ocfs2_group_desc *group;
1635
1636         mlog_entry_void();
1637
1638         if (!OCFS2_IS_VALID_DINODE(fe)) {
1639                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
1640                 status = -EIO;
1641                 goto bail;
1642         }
1643         BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
1644
1645         mlog(0, "%llu: freeing %u bits from group %llu, starting at %u\n",
1646              (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno, count,
1647              (unsigned long long)bg_blkno, start_bit);
1648
1649         status = ocfs2_read_block(osb, bg_blkno, &group_bh, OCFS2_BH_CACHED,
1650                                   alloc_inode);
1651         if (status < 0) {
1652                 mlog_errno(status);
1653                 goto bail;
1654         }
1655
1656         group = (struct ocfs2_group_desc *) group_bh->b_data;
1657         status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, group);
1658         if (status) {
1659                 mlog_errno(status);
1660                 goto bail;
1661         }
1662         BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
1663
1664         status = ocfs2_block_group_clear_bits(handle, alloc_inode,
1665                                               group, group_bh,
1666                                               start_bit, count);
1667         if (status < 0) {
1668                 mlog_errno(status);
1669                 goto bail;
1670         }
1671
1672         status = ocfs2_journal_access(handle, alloc_inode, alloc_bh,
1673                                       OCFS2_JOURNAL_ACCESS_WRITE);
1674         if (status < 0) {
1675                 mlog_errno(status);
1676                 goto bail;
1677         }
1678
1679         le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
1680                      count);
1681         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
1682         fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
1683
1684         status = ocfs2_journal_dirty(handle, alloc_bh);
1685         if (status < 0) {
1686                 mlog_errno(status);
1687                 goto bail;
1688         }
1689
1690 bail:
1691         if (group_bh)
1692                 brelse(group_bh);
1693
1694         mlog_exit(status);
1695         return status;
1696 }
1697
1698 int ocfs2_free_dinode(handle_t *handle,
1699                       struct inode *inode_alloc_inode,
1700                       struct buffer_head *inode_alloc_bh,
1701                       struct ocfs2_dinode *di)
1702 {
1703         u64 blk = le64_to_cpu(di->i_blkno);
1704         u16 bit = le16_to_cpu(di->i_suballoc_bit);
1705         u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
1706
1707         return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
1708                                         inode_alloc_bh, bit, bg_blkno, 1);
1709 }
1710
1711 int ocfs2_free_clusters(handle_t *handle,
1712                        struct inode *bitmap_inode,
1713                        struct buffer_head *bitmap_bh,
1714                        u64 start_blk,
1715                        unsigned int num_clusters)
1716 {
1717         int status;
1718         u16 bg_start_bit;
1719         u64 bg_blkno;
1720         struct ocfs2_dinode *fe;
1721
1722         /* You can't ever have a contiguous set of clusters
1723          * bigger than a block group bitmap so we never have to worry
1724          * about looping on them. */
1725
1726         mlog_entry_void();
1727
1728         /* This is expensive. We can safely remove once this stuff has
1729          * gotten tested really well. */
1730         BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb, ocfs2_blocks_to_clusters(bitmap_inode->i_sb, start_blk)));
1731
1732         fe = (struct ocfs2_dinode *) bitmap_bh->b_data;
1733
1734         ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
1735                                      &bg_start_bit);
1736
1737         mlog(0, "want to free %u clusters starting at block %llu\n",
1738              num_clusters, (unsigned long long)start_blk);
1739         mlog(0, "bg_blkno = %llu, bg_start_bit = %u\n",
1740              (unsigned long long)bg_blkno, bg_start_bit);
1741
1742         status = ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
1743                                           bg_start_bit, bg_blkno,
1744                                           num_clusters);
1745         if (status < 0)
1746                 mlog_errno(status);
1747
1748         mlog_exit(status);
1749         return status;
1750 }
1751
1752 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg)
1753 {
1754         printk("Block Group:\n");
1755         printk("bg_signature:       %s\n", bg->bg_signature);
1756         printk("bg_size:            %u\n", bg->bg_size);
1757         printk("bg_bits:            %u\n", bg->bg_bits);
1758         printk("bg_free_bits_count: %u\n", bg->bg_free_bits_count);
1759         printk("bg_chain:           %u\n", bg->bg_chain);
1760         printk("bg_generation:      %u\n", le32_to_cpu(bg->bg_generation));
1761         printk("bg_next_group:      %llu\n",
1762                (unsigned long long)bg->bg_next_group);
1763         printk("bg_parent_dinode:   %llu\n",
1764                (unsigned long long)bg->bg_parent_dinode);
1765         printk("bg_blkno:           %llu\n",
1766                (unsigned long long)bg->bg_blkno);
1767 }
1768
1769 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe)
1770 {
1771         int i;
1772
1773         printk("Suballoc Inode %llu:\n", (unsigned long long)fe->i_blkno);
1774         printk("i_signature:                  %s\n", fe->i_signature);
1775         printk("i_size:                       %llu\n",
1776                (unsigned long long)fe->i_size);
1777         printk("i_clusters:                   %u\n", fe->i_clusters);
1778         printk("i_generation:                 %u\n",
1779                le32_to_cpu(fe->i_generation));
1780         printk("id1.bitmap1.i_used:           %u\n",
1781                le32_to_cpu(fe->id1.bitmap1.i_used));
1782         printk("id1.bitmap1.i_total:          %u\n",
1783                le32_to_cpu(fe->id1.bitmap1.i_total));
1784         printk("id2.i_chain.cl_cpg:           %u\n", fe->id2.i_chain.cl_cpg);
1785         printk("id2.i_chain.cl_bpc:           %u\n", fe->id2.i_chain.cl_bpc);
1786         printk("id2.i_chain.cl_count:         %u\n", fe->id2.i_chain.cl_count);
1787         printk("id2.i_chain.cl_next_free_rec: %u\n",
1788                fe->id2.i_chain.cl_next_free_rec);
1789         for(i = 0; i < fe->id2.i_chain.cl_next_free_rec; i++) {
1790                 printk("fe->id2.i_chain.cl_recs[%d].c_free:  %u\n", i,
1791                        fe->id2.i_chain.cl_recs[i].c_free);
1792                 printk("fe->id2.i_chain.cl_recs[%d].c_total: %u\n", i,
1793                        fe->id2.i_chain.cl_recs[i].c_total);
1794                 printk("fe->id2.i_chain.cl_recs[%d].c_blkno: %llu\n", i,
1795                        (unsigned long long)fe->id2.i_chain.cl_recs[i].c_blkno);
1796         }
1797 }