fs/ocfs2/suballoc.c

   1 /* -*- mode: c; c-basic-offset: 8; -*-
   2  * vim: noexpandtab sw=8 ts=8 sts=0:
   3  *
   4  * suballoc.c
   5  *
   6  * metadata alloc and free
   7  * Inspired by ext3 block groups.
   8  *
   9  * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public
  13  * License as published by the Free Software Foundation; either
  14  * version 2 of the License, or (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19  * General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public
  22  * License along with this program; if not, write to the
  23  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  24  * Boston, MA 021110-1307, USA.
  25  */
  26
  27 #include <linux/fs.h>
  28 #include <linux/types.h>
  29 #include <linux/slab.h>
  30 #include <linux/highmem.h>
  31
  32 #include <cluster/masklog.h>
  33
  34 #include "ocfs2.h"
  35
  36 #include "alloc.h"
  37 #include "blockcheck.h"
  38 #include "dlmglue.h"
  39 #include "inode.h"
  40 #include "journal.h"
  41 #include "localalloc.h"
  42 #include "suballoc.h"
  43 #include "super.h"
  44 #include "sysfile.h"
  45 #include "uptodate.h"
  46 #include "ocfs2_trace.h"
  47
  48 #include "buffer_head_io.h"
  49
  50 #define NOT_ALLOC_NEW_GROUP             0
  51 #define ALLOC_NEW_GROUP                 0x1
  52 #define ALLOC_GROUPS_FROM_GLOBAL        0x2
  53
  54 #define OCFS2_MAX_TO_STEAL              1024
  55
  56 struct ocfs2_suballoc_result {
  57         u64             sr_bg_blkno;    /* The bg we allocated from.  Set
  58                                            to 0 when a block group is
  59                                            contiguous. */
  60         u64             sr_bg_stable_blkno; /*
  61                                              * Doesn't change, always
  62                                              * set to target block
  63                                              * group descriptor
  64                                              * block.
  65                                              */
  66         u64             sr_blkno;       /* The first allocated block */
  67         unsigned int    sr_bit_offset;  /* The bit in the bg */
  68         unsigned int    sr_bits;        /* How many bits we claimed */
  69 };
  70
  71 static u64 ocfs2_group_from_res(struct ocfs2_suballoc_result *res)
  72 {
  73         if (res->sr_blkno == 0)
  74                 return 0;
  75
  76         if (res->sr_bg_blkno)
  77                 return res->sr_bg_blkno;
  78
  79         return ocfs2_which_suballoc_group(res->sr_blkno, res->sr_bit_offset);
  80 }
  81
  82 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg);
  83 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe);
  84 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl);
  85 static int ocfs2_block_group_fill(handle_t *handle,
  86                                   struct inode *alloc_inode,
  87                                   struct buffer_head *bg_bh,
  88                                   u64 group_blkno,
  89                                   unsigned int group_clusters,
  90                                   u16 my_chain,
  91                                   struct ocfs2_chain_list *cl);
  92 static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
  93                                    struct inode *alloc_inode,
  94                                    struct buffer_head *bh,
  95                                    u64 max_block,
  96                                    u64 *last_alloc_group,
  97                                    int flags);
  98
  99 static int ocfs2_cluster_group_search(struct inode *inode,
 100                                       struct buffer_head *group_bh,
 101                                       u32 bits_wanted, u32 min_bits,
 102                                       u64 max_block,
 103                                       struct ocfs2_suballoc_result *res);
 104 static int ocfs2_block_group_search(struct inode *inode,
 105                                     struct buffer_head *group_bh,
 106                                     u32 bits_wanted, u32 min_bits,
 107                                     u64 max_block,
 108                                     struct ocfs2_suballoc_result *res);
 109 static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
 110                                      handle_t *handle,
 111                                      u32 bits_wanted,
 112                                      u32 min_bits,
 113                                      struct ocfs2_suballoc_result *res);
 114 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
 115                                          int nr);
 116 static int ocfs2_relink_block_group(handle_t *handle,
 117                                     struct inode *alloc_inode,
 118                                     struct buffer_head *fe_bh,
 119                                     struct buffer_head *bg_bh,
 120                                     struct buffer_head *prev_bg_bh,
 121                                     u16 chain);
 122 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
 123                                                      u32 wanted);
 124 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
 125                                                    u64 bg_blkno,
 126                                                    u16 bg_bit_off);
 127 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
 128                                                 u64 data_blkno,
 129                                                 u64 *bg_blkno,
 130                                                 u16 *bg_bit_off);
 131 static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
 132                                              u32 bits_wanted, u64 max_block,
 133                                              int flags,
 134                                              struct ocfs2_alloc_context **ac);
 135
 136 void ocfs2_free_ac_resource(struct ocfs2_alloc_context *ac)
 137 {
 138         struct inode *inode = ac->ac_inode;
 139
 140         if (inode) {
 141                 if (ac->ac_which != OCFS2_AC_USE_LOCAL)
 142                         ocfs2_inode_unlock(inode, 1);
 143
 144                 inode_unlock(inode);
 145
 146                 iput(inode);
 147                 ac->ac_inode = NULL;
 148         }
 149         brelse(ac->ac_bh);
 150         ac->ac_bh = NULL;
 151         ac->ac_resv = NULL;
 152         kfree(ac->ac_find_loc_priv);
 153         ac->ac_find_loc_priv = NULL;
 154 }
 155
 156 void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
 157 {
 158         ocfs2_free_ac_resource(ac);
 159         kfree(ac);
 160 }
 161
 162 static u32 ocfs2_bits_per_group(struct ocfs2_chain_list *cl)
 163 {
 164         return (u32)le16_to_cpu(cl->cl_cpg) * (u32)le16_to_cpu(cl->cl_bpc);
 165 }
 166
 167 #define do_error(fmt, ...)                                              \
 168 do {                                                                    \
 169         if (resize)                                                     \
 170                 mlog(ML_ERROR, fmt, ##__VA_ARGS__);                     \
 171         else                                                            \
 172                 return ocfs2_error(sb, fmt, ##__VA_ARGS__);             \
 173 } while (0)
 174
 175 static int ocfs2_validate_gd_self(struct super_block *sb,
 176                                   struct buffer_head *bh,
 177                                   int resize)
 178 {
 179         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 180
 181         if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
 182                 do_error("Group descriptor #%llu has bad signature %.*s\n",
 183                          (unsigned long long)bh->b_blocknr, 7,
 184                          gd->bg_signature);
 185         }
 186
 187         if (le64_to_cpu(gd->bg_blkno) != bh->b_blocknr) {
 188                 do_error("Group descriptor #%llu has an invalid bg_blkno of %llu\n",
 189                          (unsigned long long)bh->b_blocknr,
 190                          (unsigned long long)le64_to_cpu(gd->bg_blkno));
 191         }
 192
 193         if (le32_to_cpu(gd->bg_generation) != OCFS2_SB(sb)->fs_generation) {
 194                 do_error("Group descriptor #%llu has an invalid fs_generation of #%u\n",
 195                          (unsigned long long)bh->b_blocknr,
 196                          le32_to_cpu(gd->bg_generation));
 197         }
 198
 199         if (le16_to_cpu(gd->bg_free_bits_count) > le16_to_cpu(gd->bg_bits)) {
 200                 do_error("Group descriptor #%llu has bit count %u but claims that %u are free\n",
 201                          (unsigned long long)bh->b_blocknr,
 202                          le16_to_cpu(gd->bg_bits),
 203                          le16_to_cpu(gd->bg_free_bits_count));
 204         }
 205
 206         if (le16_to_cpu(gd->bg_bits) > (8 * le16_to_cpu(gd->bg_size))) {
 207                 do_error("Group descriptor #%llu has bit count %u but max bitmap bits of %u\n",
 208                          (unsigned long long)bh->b_blocknr,
 209                          le16_to_cpu(gd->bg_bits),
 210                          8 * le16_to_cpu(gd->bg_size));
 211         }
 212
 213         return 0;
 214 }
 215
 216 static int ocfs2_validate_gd_parent(struct super_block *sb,
 217                                     struct ocfs2_dinode *di,
 218                                     struct buffer_head *bh,
 219                                     int resize)
 220 {
 221         unsigned int max_bits;
 222         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 223
 224         if (di->i_blkno != gd->bg_parent_dinode) {
 225                 do_error("Group descriptor #%llu has bad parent pointer (%llu, expected %llu)\n",
 226                          (unsigned long long)bh->b_blocknr,
 227                          (unsigned long long)le64_to_cpu(gd->bg_parent_dinode),
 228                          (unsigned long long)le64_to_cpu(di->i_blkno));
 229         }
 230
 231         max_bits = le16_to_cpu(di->id2.i_chain.cl_cpg) * le16_to_cpu(di->id2.i_chain.cl_bpc);
 232         if (le16_to_cpu(gd->bg_bits) > max_bits) {
 233                 do_error("Group descriptor #%llu has bit count of %u\n",
 234                          (unsigned long long)bh->b_blocknr,
 235                          le16_to_cpu(gd->bg_bits));
 236         }
 237
 238         /* In resize, we may meet the case bg_chain == cl_next_free_rec. */
 239         if ((le16_to_cpu(gd->bg_chain) >
 240              le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) ||
 241             ((le16_to_cpu(gd->bg_chain) ==
 242              le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) && !resize)) {
 243                 do_error("Group descriptor #%llu has bad chain %u\n",
 244                          (unsigned long long)bh->b_blocknr,
 245                          le16_to_cpu(gd->bg_chain));
 246         }
 247
 248         return 0;
 249 }
 250
 251 #undef do_error
 252
 253 /*
 254  * This version only prints errors.  It does not fail the filesystem, and
 255  * exists only for resize.
 256  */
 257 int ocfs2_check_group_descriptor(struct super_block *sb,
 258                                  struct ocfs2_dinode *di,
 259                                  struct buffer_head *bh)
 260 {
 261         int rc;
 262         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 263
 264         BUG_ON(!buffer_uptodate(bh));
 265
 266         /*
 267          * If the ecc fails, we return the error but otherwise
 268          * leave the filesystem running.  We know any error is
 269          * local to this block.
 270          */
 271         rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
 272         if (rc) {
 273                 mlog(ML_ERROR,
 274                      "Checksum failed for group descriptor %llu\n",
 275                      (unsigned long long)bh->b_blocknr);
 276         } else
 277                 rc = ocfs2_validate_gd_self(sb, bh, 1);
 278         if (!rc)
 279                 rc = ocfs2_validate_gd_parent(sb, di, bh, 1);
 280
 281         return rc;
 282 }
 283
 284 static int ocfs2_validate_group_descriptor(struct super_block *sb,
 285                                            struct buffer_head *bh)
 286 {
 287         int rc;
 288         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
 289
 290         trace_ocfs2_validate_group_descriptor(
 291                                         (unsigned long long)bh->b_blocknr);
 292
 293         BUG_ON(!buffer_uptodate(bh));
 294
 295         /*
 296          * If the ecc fails, we return the error but otherwise
 297          * leave the filesystem running.  We know any error is
 298          * local to this block.
 299          */
 300         rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &gd->bg_check);
 301         if (rc)
 302                 return rc;
 303
 304         /*
 305          * Errors after here are fatal.
 306          */
 307
 308         return ocfs2_validate_gd_self(sb, bh, 0);
 309 }
 310
 311 int ocfs2_read_group_descriptor(struct inode *inode, struct ocfs2_dinode *di,
 312                                 u64 gd_blkno, struct buffer_head **bh)
 313 {
 314         int rc;
 315         struct buffer_head *tmp = *bh;
 316
 317         rc = ocfs2_read_block(INODE_CACHE(inode), gd_blkno, &tmp,
 318                               ocfs2_validate_group_descriptor);
 319         if (rc)
 320                 goto out;
 321
 322         rc = ocfs2_validate_gd_parent(inode->i_sb, di, tmp, 0);
 323         if (rc) {
 324                 brelse(tmp);
 325                 goto out;
 326         }
 327
 328         /* If ocfs2_read_block() got us a new bh, pass it up. */
 329         if (!*bh)
 330                 *bh = tmp;
 331
 332 out:
 333         return rc;
 334 }
 335
 336 static void ocfs2_bg_discontig_add_extent(struct ocfs2_super *osb,
 337                                           struct ocfs2_group_desc *bg,
 338                                           struct ocfs2_chain_list *cl,
 339                                           u64 p_blkno, unsigned int clusters)
 340 {
 341         struct ocfs2_extent_list *el = &bg->bg_list;
 342         struct ocfs2_extent_rec *rec;
 343
 344         BUG_ON(!ocfs2_supports_discontig_bg(osb));
 345         if (!el->l_next_free_rec)
 346                 el->l_count = cpu_to_le16(ocfs2_extent_recs_per_gd(osb->sb));
 347         rec = &el->l_recs[le16_to_cpu(el->l_next_free_rec)];
 348         rec->e_blkno = cpu_to_le64(p_blkno);
 349         rec->e_cpos = cpu_to_le32(le16_to_cpu(bg->bg_bits) /
 350                                   le16_to_cpu(cl->cl_bpc));
 351         rec->e_leaf_clusters = cpu_to_le16(clusters);
 352         le16_add_cpu(&bg->bg_bits, clusters * le16_to_cpu(cl->cl_bpc));
 353         le16_add_cpu(&bg->bg_free_bits_count,
 354                      clusters * le16_to_cpu(cl->cl_bpc));
 355         le16_add_cpu(&el->l_next_free_rec, 1);
 356 }
 357
 358 static int ocfs2_block_group_fill(handle_t *handle,
 359                                   struct inode *alloc_inode,
 360                                   struct buffer_head *bg_bh,
 361                                   u64 group_blkno,
 362                                   unsigned int group_clusters,
 363                                   u16 my_chain,
 364                                   struct ocfs2_chain_list *cl)
 365 {
 366         int status = 0;
 367         struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 368         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 369         struct super_block * sb = alloc_inode->i_sb;
 370
 371         if (((unsigned long long) bg_bh->b_blocknr) != group_blkno) {
 372                 status = ocfs2_error(alloc_inode->i_sb,
 373                                      "group block (%llu) != b_blocknr (%llu)\n",
 374                                      (unsigned long long)group_blkno,
 375                                      (unsigned long long) bg_bh->b_blocknr);
 376                 goto bail;
 377         }
 378
 379         status = ocfs2_journal_access_gd(handle,
 380                                          INODE_CACHE(alloc_inode),
 381                                          bg_bh,
 382                                          OCFS2_JOURNAL_ACCESS_CREATE);
 383         if (status < 0) {
 384                 mlog_errno(status);
 385                 goto bail;
 386         }
 387
 388         memset(bg, 0, sb->s_blocksize);
 389         strcpy(bg->bg_signature, OCFS2_GROUP_DESC_SIGNATURE);
 390         bg->bg_generation = cpu_to_le32(OCFS2_SB(sb)->fs_generation);
 391         bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb, 1,
 392                                                 osb->s_feature_incompat));
 393         bg->bg_chain = cpu_to_le16(my_chain);
 394         bg->bg_next_group = cl->cl_recs[my_chain].c_blkno;
 395         bg->bg_parent_dinode = cpu_to_le64(OCFS2_I(alloc_inode)->ip_blkno);
 396         bg->bg_blkno = cpu_to_le64(group_blkno);
 397         if (group_clusters == le16_to_cpu(cl->cl_cpg))
 398                 bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
 399         else
 400                 ocfs2_bg_discontig_add_extent(osb, bg, cl, group_blkno,
 401                                               group_clusters);
 402
 403         /* set the 1st bit in the bitmap to account for the descriptor block */
 404         ocfs2_set_bit(0, (unsigned long *)bg->bg_bitmap);
 405         bg->bg_free_bits_count = cpu_to_le16(le16_to_cpu(bg->bg_bits) - 1);
 406
 407         ocfs2_journal_dirty(handle, bg_bh);
 408
 409         /* There is no need to zero out or otherwise initialize the
 410          * other blocks in a group - All valid FS metadata in a block
 411          * group stores the superblock fs_generation value at
 412          * allocation time. */
 413
 414 bail:
 415         if (status)
 416                 mlog_errno(status);
 417         return status;
 418 }
 419
 420 static inline u16 ocfs2_find_smallest_chain(struct ocfs2_chain_list *cl)
 421 {
 422         u16 curr, best;
 423
 424         best = curr = 0;
 425         while (curr < le16_to_cpu(cl->cl_count)) {
 426                 if (le32_to_cpu(cl->cl_recs[best].c_total) >
 427                     le32_to_cpu(cl->cl_recs[curr].c_total))
 428                         best = curr;
 429                 curr++;
 430         }
 431         return best;
 432 }
 433
 434 static struct buffer_head *
 435 ocfs2_block_group_alloc_contig(struct ocfs2_super *osb, handle_t *handle,
 436                                struct inode *alloc_inode,
 437                                struct ocfs2_alloc_context *ac,
 438                                struct ocfs2_chain_list *cl)
 439 {
 440         int status;
 441         u32 bit_off, num_bits;
 442         u64 bg_blkno;
 443         struct buffer_head *bg_bh;
 444         unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
 445
 446         status = ocfs2_claim_clusters(handle, ac,
 447                                       le16_to_cpu(cl->cl_cpg), &bit_off,
 448                                       &num_bits);
 449         if (status < 0) {
 450                 if (status != -ENOSPC)
 451                         mlog_errno(status);
 452                 goto bail;
 453         }
 454
 455         /* setup the group */
 456         bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 457         trace_ocfs2_block_group_alloc_contig(
 458              (unsigned long long)bg_blkno, alloc_rec);
 459
 460         bg_bh = sb_getblk(osb->sb, bg_blkno);
 461         if (!bg_bh) {
 462                 status = -ENOMEM;
 463                 mlog_errno(status);
 464                 goto bail;
 465         }
 466         ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
 467
 468         status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
 469                                         bg_blkno, num_bits, alloc_rec, cl);
 470         if (status < 0) {
 471                 brelse(bg_bh);
 472                 mlog_errno(status);
 473         }
 474
 475 bail:
 476         return status ? ERR_PTR(status) : bg_bh;
 477 }
 478
 479 static int ocfs2_block_group_claim_bits(struct ocfs2_super *osb,
 480                                         handle_t *handle,
 481                                         struct ocfs2_alloc_context *ac,
 482                                         unsigned int min_bits,
 483                                         u32 *bit_off, u32 *num_bits)
 484 {
 485         int status = 0;
 486
 487         while (min_bits) {
 488                 status = ocfs2_claim_clusters(handle, ac, min_bits,
 489                                               bit_off, num_bits);
 490                 if (status != -ENOSPC)
 491                         break;
 492
 493                 min_bits >>= 1;
 494         }
 495
 496         return status;
 497 }
 498
 499 static int ocfs2_block_group_grow_discontig(handle_t *handle,
 500                                             struct inode *alloc_inode,
 501                                             struct buffer_head *bg_bh,
 502                                             struct ocfs2_alloc_context *ac,
 503                                             struct ocfs2_chain_list *cl,
 504                                             unsigned int min_bits)
 505 {
 506         int status;
 507         struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 508         struct ocfs2_group_desc *bg =
 509                 (struct ocfs2_group_desc *)bg_bh->b_data;
 510         unsigned int needed = le16_to_cpu(cl->cl_cpg) -
 511                          le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
 512         u32 p_cpos, clusters;
 513         u64 p_blkno;
 514         struct ocfs2_extent_list *el = &bg->bg_list;
 515
 516         status = ocfs2_journal_access_gd(handle,
 517                                          INODE_CACHE(alloc_inode),
 518                                          bg_bh,
 519                                          OCFS2_JOURNAL_ACCESS_CREATE);
 520         if (status < 0) {
 521                 mlog_errno(status);
 522                 goto bail;
 523         }
 524
 525         while ((needed > 0) && (le16_to_cpu(el->l_next_free_rec) <
 526                                 le16_to_cpu(el->l_count))) {
 527                 if (min_bits > needed)
 528                         min_bits = needed;
 529                 status = ocfs2_block_group_claim_bits(osb, handle, ac,
 530                                                       min_bits, &p_cpos,
 531                                                       &clusters);
 532                 if (status < 0) {
 533                         if (status != -ENOSPC)
 534                                 mlog_errno(status);
 535                         goto bail;
 536                 }
 537                 p_blkno = ocfs2_clusters_to_blocks(osb->sb, p_cpos);
 538                 ocfs2_bg_discontig_add_extent(osb, bg, cl, p_blkno,
 539                                               clusters);
 540
 541                 min_bits = clusters;
 542                 needed = le16_to_cpu(cl->cl_cpg) -
 543                          le16_to_cpu(bg->bg_bits) / le16_to_cpu(cl->cl_bpc);
 544         }
 545
 546         if (needed > 0) {
 547                 /*
 548                  * We have used up all the extent rec but can't fill up
 549                  * the cpg. So bail out.
 550                  */
 551                 status = -ENOSPC;
 552                 goto bail;
 553         }
 554
 555         ocfs2_journal_dirty(handle, bg_bh);
 556
 557 bail:
 558         return status;
 559 }
 560
 561 static void ocfs2_bg_alloc_cleanup(handle_t *handle,
 562                                    struct ocfs2_alloc_context *cluster_ac,
 563                                    struct inode *alloc_inode,
 564                                    struct buffer_head *bg_bh)
 565 {
 566         int i, ret;
 567         struct ocfs2_group_desc *bg;
 568         struct ocfs2_extent_list *el;
 569         struct ocfs2_extent_rec *rec;
 570
 571         if (!bg_bh)
 572                 return;
 573
 574         bg = (struct ocfs2_group_desc *)bg_bh->b_data;
 575         el = &bg->bg_list;
 576         for (i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
 577                 rec = &el->l_recs[i];
 578                 ret = ocfs2_free_clusters(handle, cluster_ac->ac_inode,
 579                                           cluster_ac->ac_bh,
 580                                           le64_to_cpu(rec->e_blkno),
 581                                           le16_to_cpu(rec->e_leaf_clusters));
 582                 if (ret)
 583                         mlog_errno(ret);
 584                 /* Try all the clusters to free */
 585         }
 586
 587         ocfs2_remove_from_cache(INODE_CACHE(alloc_inode), bg_bh);
 588         brelse(bg_bh);
 589 }
 590
 591 static struct buffer_head *
 592 ocfs2_block_group_alloc_discontig(handle_t *handle,
 593                                   struct inode *alloc_inode,
 594                                   struct ocfs2_alloc_context *ac,
 595                                   struct ocfs2_chain_list *cl)
 596 {
 597         int status;
 598         u32 bit_off, num_bits;
 599         u64 bg_blkno;
 600         unsigned int min_bits = le16_to_cpu(cl->cl_cpg) >> 1;
 601         struct buffer_head *bg_bh = NULL;
 602         unsigned int alloc_rec = ocfs2_find_smallest_chain(cl);
 603         struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
 604
 605         if (!ocfs2_supports_discontig_bg(osb)) {
 606                 status = -ENOSPC;
 607                 goto bail;
 608         }
 609
 610         status = ocfs2_extend_trans(handle,
 611                                     ocfs2_calc_bg_discontig_credits(osb->sb));
 612         if (status) {
 613                 mlog_errno(status);
 614                 goto bail;
 615         }
 616
 617         /*
 618          * We're going to be grabbing from multiple cluster groups.
 619          * We don't have enough credits to relink them all, and the
 620          * cluster groups will be staying in cache for the duration of
 621          * this operation.
 622          */
 623         ac->ac_disable_chain_relink = 1;
 624
 625         /* Claim the first region */
 626         status = ocfs2_block_group_claim_bits(osb, handle, ac, min_bits,
 627                                               &bit_off, &num_bits);
 628         if (status < 0) {
 629                 if (status != -ENOSPC)
 630                         mlog_errno(status);
 631                 goto bail;
 632         }
 633         min_bits = num_bits;
 634
 635         /* setup the group */
 636         bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
 637         trace_ocfs2_block_group_alloc_discontig(
 638                                 (unsigned long long)bg_blkno, alloc_rec);
 639
 640         bg_bh = sb_getblk(osb->sb, bg_blkno);
 641         if (!bg_bh) {
 642                 status = -ENOMEM;
 643                 mlog_errno(status);
 644                 goto bail;
 645         }
 646         ocfs2_set_new_buffer_uptodate(INODE_CACHE(alloc_inode), bg_bh);
 647
 648         status = ocfs2_block_group_fill(handle, alloc_inode, bg_bh,
 649                                         bg_blkno, num_bits, alloc_rec, cl);
 650         if (status < 0) {
 651                 mlog_errno(status);
 652                 goto bail;
 653         }
 654
 655         status = ocfs2_block_group_grow_discontig(handle, alloc_inode,
 656                                                   bg_bh, ac, cl, min_bits);
 657         if (status)
 658                 mlog_errno(status);
 659
 660 bail:
 661         if (status)
 662                 ocfs2_bg_alloc_cleanup(handle, ac, alloc_inode, bg_bh);
 663         return status ? ERR_PTR(status) : bg_bh;
 664 }
 665
 666 /*
 667  * We expect the block group allocator to already be locked.
 668  */
 669 static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
 670                                    struct inode *alloc_inode,
 671                                    struct buffer_head *bh,
 672                                    u64 max_block,
 673                                    u64 *last_alloc_group,
 674                                    int flags)
 675 {
 676         int status, credits;
 677         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) bh->b_data;
 678         struct ocfs2_chain_list *cl;
 679         struct ocfs2_alloc_context *ac = NULL;
 680         handle_t *handle = NULL;
 681         u16 alloc_rec;
 682         struct buffer_head *bg_bh = NULL;
 683         struct ocfs2_group_desc *bg;
 684
 685         BUG_ON(ocfs2_is_cluster_bitmap(alloc_inode));
 686
 687         cl = &fe->id2.i_chain;
 688         status = ocfs2_reserve_clusters_with_limit(osb,
 689                                                    le16_to_cpu(cl->cl_cpg),
 690                                                    max_block, flags, &ac);
 691         if (status < 0) {
 692                 if (status != -ENOSPC)
 693                         mlog_errno(status);
 694                 goto bail;
 695         }
 696
 697         credits = ocfs2_calc_group_alloc_credits(osb->sb,
 698                                                  le16_to_cpu(cl->cl_cpg));
 699         handle = ocfs2_start_trans(osb, credits);
 700         if (IS_ERR(handle)) {
 701                 status = PTR_ERR(handle);
 702                 handle = NULL;
 703                 mlog_errno(status);
 704                 goto bail;
 705         }
 706
 707         if (last_alloc_group && *last_alloc_group != 0) {
 708                 trace_ocfs2_block_group_alloc(
 709                                 (unsigned long long)*last_alloc_group);
 710                 ac->ac_last_group = *last_alloc_group;
 711         }
 712
 713         bg_bh = ocfs2_block_group_alloc_contig(osb, handle, alloc_inode,
 714                                                ac, cl);
 715         if (IS_ERR(bg_bh) && (PTR_ERR(bg_bh) == -ENOSPC))
 716                 bg_bh = ocfs2_block_group_alloc_discontig(handle,
 717                                                           alloc_inode,
 718                                                           ac, cl);
 719         if (IS_ERR(bg_bh)) {
 720                 status = PTR_ERR(bg_bh);
 721                 bg_bh = NULL;
 722                 if (status != -ENOSPC)
 723                         mlog_errno(status);
 724                 goto bail;
 725         }
 726         bg = (struct ocfs2_group_desc *) bg_bh->b_data;
 727
 728         status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
 729                                          bh, OCFS2_JOURNAL_ACCESS_WRITE);
 730         if (status < 0) {
 731                 mlog_errno(status);
 732                 goto bail;
 733         }
 734
 735         alloc_rec = le16_to_cpu(bg->bg_chain);
 736         le32_add_cpu(&cl->cl_recs[alloc_rec].c_free,
 737                      le16_to_cpu(bg->bg_free_bits_count));
 738         le32_add_cpu(&cl->cl_recs[alloc_rec].c_total,
 739                      le16_to_cpu(bg->bg_bits));
 740         cl->cl_recs[alloc_rec].c_blkno = bg->bg_blkno;
 741         if (le16_to_cpu(cl->cl_next_free_rec) < le16_to_cpu(cl->cl_count))
 742                 le16_add_cpu(&cl->cl_next_free_rec, 1);
 743
 744         le32_add_cpu(&fe->id1.bitmap1.i_used, le16_to_cpu(bg->bg_bits) -
 745                                         le16_to_cpu(bg->bg_free_bits_count));
 746         le32_add_cpu(&fe->id1.bitmap1.i_total, le16_to_cpu(bg->bg_bits));
 747         le32_add_cpu(&fe->i_clusters, le16_to_cpu(cl->cl_cpg));
 748
 749         ocfs2_journal_dirty(handle, bh);
 750
 751         spin_lock(&OCFS2_I(alloc_inode)->ip_lock);
 752         OCFS2_I(alloc_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
 753         fe->i_size = cpu_to_le64(ocfs2_clusters_to_bytes(alloc_inode->i_sb,
 754                                              le32_to_cpu(fe->i_clusters)));
 755         spin_unlock(&OCFS2_I(alloc_inode)->ip_lock);
 756         i_size_write(alloc_inode, le64_to_cpu(fe->i_size));
 757         alloc_inode->i_blocks = ocfs2_inode_sector_count(alloc_inode);
 758         ocfs2_update_inode_fsync_trans(handle, alloc_inode, 0);
 759
 760         status = 0;
 761
 762         /* save the new last alloc group so that the caller can cache it. */
 763         if (last_alloc_group)
 764                 *last_alloc_group = ac->ac_last_group;
 765
 766 bail:
 767         if (handle)
 768                 ocfs2_commit_trans(osb, handle);
 769
 770         if (ac)
 771                 ocfs2_free_alloc_context(ac);
 772
 773         brelse(bg_bh);
 774
 775         if (status)
 776                 mlog_errno(status);
 777         return status;
 778 }
 779
 780 static int ocfs2_reserve_suballoc_bits(struct ocfs2_super *osb,
 781                                        struct ocfs2_alloc_context *ac,
 782                                        int type,
 783                                        u32 slot,
 784                                        u64 *last_alloc_group,
 785                                        int flags)
 786 {
 787         int status;
 788         u32 bits_wanted = ac->ac_bits_wanted;
 789         struct inode *alloc_inode;
 790         struct buffer_head *bh = NULL;
 791         struct ocfs2_dinode *fe;
 792         u32 free_bits;
 793
 794         alloc_inode = ocfs2_get_system_file_inode(osb, type, slot);
 795         if (!alloc_inode) {
 796                 mlog_errno(-EINVAL);
 797                 return -EINVAL;
 798         }
 799
 800         inode_lock(alloc_inode);
 801
 802         status = ocfs2_inode_lock(alloc_inode, &bh, 1);
 803         if (status < 0) {
 804                 inode_unlock(alloc_inode);
 805                 iput(alloc_inode);
 806
 807                 mlog_errno(status);
 808                 return status;
 809         }
 810
 811         ac->ac_inode = alloc_inode;
 812         ac->ac_alloc_slot = slot;
 813
 814         fe = (struct ocfs2_dinode *) bh->b_data;
 815
 816         /* The bh was validated by the inode read inside
 817          * ocfs2_inode_lock().  Any corruption is a code bug. */
 818         BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
 819
 820         if (!(fe->i_flags & cpu_to_le32(OCFS2_CHAIN_FL))) {
 821                 status = ocfs2_error(alloc_inode->i_sb,
 822                                      "Invalid chain allocator %llu\n",
 823                                      (unsigned long long)le64_to_cpu(fe->i_blkno));
 824                 goto bail;
 825         }
 826
 827         free_bits = le32_to_cpu(fe->id1.bitmap1.i_total) -
 828                 le32_to_cpu(fe->id1.bitmap1.i_used);
 829
 830         if (bits_wanted > free_bits) {
 831                 /* cluster bitmap never grows */
 832                 if (ocfs2_is_cluster_bitmap(alloc_inode)) {
 833                         trace_ocfs2_reserve_suballoc_bits_nospc(bits_wanted,
 834                                                                 free_bits);
 835                         status = -ENOSPC;
 836                         goto bail;
 837                 }
 838
 839                 if (!(flags & ALLOC_NEW_GROUP)) {
 840                         trace_ocfs2_reserve_suballoc_bits_no_new_group(
 841                                                 slot, bits_wanted, free_bits);
 842                         status = -ENOSPC;
 843                         goto bail;
 844                 }
 845
 846                 status = ocfs2_block_group_alloc(osb, alloc_inode, bh,
 847                                                  ac->ac_max_block,
 848                                                  last_alloc_group, flags);
 849                 if (status < 0) {
 850                         if (status != -ENOSPC)
 851                                 mlog_errno(status);
 852                         goto bail;
 853                 }
 854                 atomic_inc(&osb->alloc_stats.bg_extends);
 855
 856                 /* You should never ask for this much metadata */
 857                 BUG_ON(bits_wanted >
 858                        (le32_to_cpu(fe->id1.bitmap1.i_total)
 859                         - le32_to_cpu(fe->id1.bitmap1.i_used)));
 860         }
 861
 862         get_bh(bh);
 863         ac->ac_bh = bh;
 864 bail:
 865         brelse(bh);
 866
 867         if (status)
 868                 mlog_errno(status);
 869         return status;
 870 }
 871
 872 static void ocfs2_init_inode_steal_slot(struct ocfs2_super *osb)
 873 {
 874         spin_lock(&osb->osb_lock);
 875         osb->s_inode_steal_slot = OCFS2_INVALID_SLOT;
 876         spin_unlock(&osb->osb_lock);
 877         atomic_set(&osb->s_num_inodes_stolen, 0);
 878 }
 879
 880 static void ocfs2_init_meta_steal_slot(struct ocfs2_super *osb)
 881 {
 882         spin_lock(&osb->osb_lock);
 883         osb->s_meta_steal_slot = OCFS2_INVALID_SLOT;
 884         spin_unlock(&osb->osb_lock);
 885         atomic_set(&osb->s_num_meta_stolen, 0);
 886 }
 887
 888 void ocfs2_init_steal_slots(struct ocfs2_super *osb)
 889 {
 890         ocfs2_init_inode_steal_slot(osb);
 891         ocfs2_init_meta_steal_slot(osb);
 892 }
 893
 894 static void __ocfs2_set_steal_slot(struct ocfs2_super *osb, int slot, int type)
 895 {
 896         spin_lock(&osb->osb_lock);
 897         if (type == INODE_ALLOC_SYSTEM_INODE)
 898                 osb->s_inode_steal_slot = (u16)slot;
 899         else if (type == EXTENT_ALLOC_SYSTEM_INODE)
 900                 osb->s_meta_steal_slot = (u16)slot;
 901         spin_unlock(&osb->osb_lock);
 902 }
 903
 904 static int __ocfs2_get_steal_slot(struct ocfs2_super *osb, int type)
 905 {
 906         int slot = OCFS2_INVALID_SLOT;
 907
 908         spin_lock(&osb->osb_lock);
 909         if (type == INODE_ALLOC_SYSTEM_INODE)
 910                 slot = osb->s_inode_steal_slot;
 911         else if (type == EXTENT_ALLOC_SYSTEM_INODE)
 912                 slot = osb->s_meta_steal_slot;
 913         spin_unlock(&osb->osb_lock);
 914
 915         return slot;
 916 }
 917
 918 static int ocfs2_get_inode_steal_slot(struct ocfs2_super *osb)
 919 {
 920         return __ocfs2_get_steal_slot(osb, INODE_ALLOC_SYSTEM_INODE);
 921 }
 922
 923 static int ocfs2_get_meta_steal_slot(struct ocfs2_super *osb)
 924 {
 925         return __ocfs2_get_steal_slot(osb, EXTENT_ALLOC_SYSTEM_INODE);
 926 }
 927
 928 static int ocfs2_steal_resource(struct ocfs2_super *osb,
 929                                 struct ocfs2_alloc_context *ac,
 930                                 int type)
 931 {
 932         int i, status = -ENOSPC;
 933         int slot = __ocfs2_get_steal_slot(osb, type);
 934
 935         /* Start to steal resource from the first slot after ours. */
 936         if (slot == OCFS2_INVALID_SLOT)
 937                 slot = osb->slot_num + 1;
 938
 939         for (i = 0; i < osb->max_slots; i++, slot++) {
 940                 if (slot == osb->max_slots)
 941                         slot = 0;
 942
 943                 if (slot == osb->slot_num)
 944                         continue;
 945
 946                 status = ocfs2_reserve_suballoc_bits(osb, ac,
 947                                                      type,
 948                                                      (u32)slot, NULL,
 949                                                      NOT_ALLOC_NEW_GROUP);
 950                 if (status >= 0) {
 951                         __ocfs2_set_steal_slot(osb, slot, type);
 952                         break;
 953                 }
 954
 955                 ocfs2_free_ac_resource(ac);
 956         }
 957
 958         return status;
 959 }
 960
 961 static int ocfs2_steal_inode(struct ocfs2_super *osb,
 962                              struct ocfs2_alloc_context *ac)
 963 {
 964         return ocfs2_steal_resource(osb, ac, INODE_ALLOC_SYSTEM_INODE);
 965 }
 966
 967 static int ocfs2_steal_meta(struct ocfs2_super *osb,
 968                             struct ocfs2_alloc_context *ac)
 969 {
 970         return ocfs2_steal_resource(osb, ac, EXTENT_ALLOC_SYSTEM_INODE);
 971 }
 972
 973 int ocfs2_reserve_new_metadata_blocks(struct ocfs2_super *osb,
 974                                       int blocks,
 975                                       struct ocfs2_alloc_context **ac)
 976 {
 977         int status;
 978         int slot = ocfs2_get_meta_steal_slot(osb);
 979
 980         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
 981         if (!(*ac)) {
 982                 status = -ENOMEM;
 983                 mlog_errno(status);
 984                 goto bail;
 985         }
 986
 987         (*ac)->ac_bits_wanted = blocks;
 988         (*ac)->ac_which = OCFS2_AC_USE_META;
 989         (*ac)->ac_group_search = ocfs2_block_group_search;
 990
 991         if (slot != OCFS2_INVALID_SLOT &&
 992                 atomic_read(&osb->s_num_meta_stolen) < OCFS2_MAX_TO_STEAL)
 993                 goto extent_steal;
 994
 995         atomic_set(&osb->s_num_meta_stolen, 0);
 996         status = ocfs2_reserve_suballoc_bits(osb, (*ac),
 997                                              EXTENT_ALLOC_SYSTEM_INODE,
 998                                              (u32)osb->slot_num, NULL,
 999                                              ALLOC_GROUPS_FROM_GLOBAL|ALLOC_NEW_GROUP);
1000
1001
1002         if (status >= 0) {
1003                 status = 0;
1004                 if (slot != OCFS2_INVALID_SLOT)
1005                         ocfs2_init_meta_steal_slot(osb);
1006                 goto bail;
1007         } else if (status < 0 && status != -ENOSPC) {
1008                 mlog_errno(status);
1009                 goto bail;
1010         }
1011
1012         ocfs2_free_ac_resource(*ac);
1013
1014 extent_steal:
1015         status = ocfs2_steal_meta(osb, *ac);
1016         atomic_inc(&osb->s_num_meta_stolen);
1017         if (status < 0) {
1018                 if (status != -ENOSPC)
1019                         mlog_errno(status);
1020                 goto bail;
1021         }
1022
1023         status = 0;
1024 bail:
1025         if ((status < 0) && *ac) {
1026                 ocfs2_free_alloc_context(*ac);
1027                 *ac = NULL;
1028         }
1029
1030         if (status)
1031                 mlog_errno(status);
1032         return status;
1033 }
1034
1035 int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
1036                                struct ocfs2_extent_list *root_el,
1037                                struct ocfs2_alloc_context **ac)
1038 {
1039         return ocfs2_reserve_new_metadata_blocks(osb,
1040                                         ocfs2_extend_meta_needed(root_el),
1041                                         ac);
1042 }
1043
1044 int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
1045                             struct ocfs2_alloc_context **ac)
1046 {
1047         int status;
1048         int slot = ocfs2_get_inode_steal_slot(osb);
1049         u64 alloc_group;
1050
1051         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1052         if (!(*ac)) {
1053                 status = -ENOMEM;
1054                 mlog_errno(status);
1055                 goto bail;
1056         }
1057
1058         (*ac)->ac_bits_wanted = 1;
1059         (*ac)->ac_which = OCFS2_AC_USE_INODE;
1060
1061         (*ac)->ac_group_search = ocfs2_block_group_search;
1062
1063         /*
1064          * stat(2) can't handle i_ino > 32bits, so we tell the
1065          * lower levels not to allocate us a block group past that
1066          * limit.  The 'inode64' mount option avoids this behavior.
1067          */
1068         if (!(osb->s_mount_opt & OCFS2_MOUNT_INODE64))
1069                 (*ac)->ac_max_block = (u32)~0U;
1070
1071         /*
1072          * slot is set when we successfully steal inode from other nodes.
1073          * It is reset in 3 places:
1074          * 1. when we flush the truncate log
1075          * 2. when we complete local alloc recovery.
1076          * 3. when we successfully allocate from our own slot.
1077          * After it is set, we will go on stealing inodes until we find the
1078          * need to check our slots to see whether there is some space for us.
1079          */
1080         if (slot != OCFS2_INVALID_SLOT &&
1081             atomic_read(&osb->s_num_inodes_stolen) < OCFS2_MAX_TO_STEAL)
1082                 goto inode_steal;
1083
1084         atomic_set(&osb->s_num_inodes_stolen, 0);
1085         alloc_group = osb->osb_inode_alloc_group;
1086         status = ocfs2_reserve_suballoc_bits(osb, *ac,
1087                                              INODE_ALLOC_SYSTEM_INODE,
1088                                              (u32)osb->slot_num,
1089                                              &alloc_group,
1090                                              ALLOC_NEW_GROUP |
1091                                              ALLOC_GROUPS_FROM_GLOBAL);
1092         if (status >= 0) {
1093                 status = 0;
1094
1095                 spin_lock(&osb->osb_lock);
1096                 osb->osb_inode_alloc_group = alloc_group;
1097                 spin_unlock(&osb->osb_lock);
1098                 trace_ocfs2_reserve_new_inode_new_group(
1099                         (unsigned long long)alloc_group);
1100
1101                 /*
1102                  * Some inodes must be freed by us, so try to allocate
1103                  * from our own next time.
1104                  */
1105                 if (slot != OCFS2_INVALID_SLOT)
1106                         ocfs2_init_inode_steal_slot(osb);
1107                 goto bail;
1108         } else if (status < 0 && status != -ENOSPC) {
1109                 mlog_errno(status);
1110                 goto bail;
1111         }
1112
1113         ocfs2_free_ac_resource(*ac);
1114
1115 inode_steal:
1116         status = ocfs2_steal_inode(osb, *ac);
1117         atomic_inc(&osb->s_num_inodes_stolen);
1118         if (status < 0) {
1119                 if (status != -ENOSPC)
1120                         mlog_errno(status);
1121                 goto bail;
1122         }
1123
1124         status = 0;
1125 bail:
1126         if ((status < 0) && *ac) {
1127                 ocfs2_free_alloc_context(*ac);
1128                 *ac = NULL;
1129         }
1130
1131         if (status)
1132                 mlog_errno(status);
1133         return status;
1134 }
1135
1136 /* local alloc code has to do the same thing, so rather than do this
1137  * twice.. */
1138 int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
1139                                       struct ocfs2_alloc_context *ac)
1140 {
1141         int status;
1142
1143         ac->ac_which = OCFS2_AC_USE_MAIN;
1144         ac->ac_group_search = ocfs2_cluster_group_search;
1145
1146         status = ocfs2_reserve_suballoc_bits(osb, ac,
1147                                              GLOBAL_BITMAP_SYSTEM_INODE,
1148                                              OCFS2_INVALID_SLOT, NULL,
1149                                              ALLOC_NEW_GROUP);
1150         if (status < 0 && status != -ENOSPC) {
1151                 mlog_errno(status);
1152                 goto bail;
1153         }
1154
1155 bail:
1156         return status;
1157 }
1158
1159 /* Callers don't need to care which bitmap (local alloc or main) to
1160  * use so we figure it out for them, but unfortunately this clutters
1161  * things a bit. */
1162 static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
1163                                              u32 bits_wanted, u64 max_block,
1164                                              int flags,
1165                                              struct ocfs2_alloc_context **ac)
1166 {
1167         int status, ret = 0;
1168         int retried = 0;
1169
1170         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1171         if (!(*ac)) {
1172                 status = -ENOMEM;
1173                 mlog_errno(status);
1174                 goto bail;
1175         }
1176
1177         (*ac)->ac_bits_wanted = bits_wanted;
1178         (*ac)->ac_max_block = max_block;
1179
1180         status = -ENOSPC;
1181         if (!(flags & ALLOC_GROUPS_FROM_GLOBAL) &&
1182             ocfs2_alloc_should_use_local(osb, bits_wanted)) {
1183                 status = ocfs2_reserve_local_alloc_bits(osb,
1184                                                         bits_wanted,
1185                                                         *ac);
1186                 if ((status < 0) && (status != -ENOSPC)) {
1187                         mlog_errno(status);
1188                         goto bail;
1189                 }
1190         }
1191
1192         if (status == -ENOSPC) {
1193 retry:
1194                 status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
1195                 /* Retry if there is sufficient space cached in truncate log */
1196                 if (status == -ENOSPC && !retried) {
1197                         retried = 1;
1198                         ocfs2_inode_unlock((*ac)->ac_inode, 1);
1199                         inode_unlock((*ac)->ac_inode);
1200
1201                         ret = ocfs2_try_to_free_truncate_log(osb, bits_wanted);
1202                         if (ret == 1) {
1203                                 iput((*ac)->ac_inode);
1204                                 (*ac)->ac_inode = NULL;
1205                                 goto retry;
1206                         }
1207
1208                         if (ret < 0)
1209                                 mlog_errno(ret);
1210
1211                         inode_lock((*ac)->ac_inode);
1212                         ret = ocfs2_inode_lock((*ac)->ac_inode, NULL, 1);
1213                         if (ret < 0) {
1214                                 mlog_errno(ret);
1215                                 inode_unlock((*ac)->ac_inode);
1216                                 iput((*ac)->ac_inode);
1217                                 (*ac)->ac_inode = NULL;
1218                                 goto bail;
1219                         }
1220                 }
1221                 if (status < 0) {
1222                         if (status != -ENOSPC)
1223                                 mlog_errno(status);
1224                         goto bail;
1225                 }
1226         }
1227
1228         status = 0;
1229 bail:
1230         if ((status < 0) && *ac) {
1231                 ocfs2_free_alloc_context(*ac);
1232                 *ac = NULL;
1233         }
1234
1235         if (status)
1236                 mlog_errno(status);
1237         return status;
1238 }
1239
1240 int ocfs2_reserve_clusters(struct ocfs2_super *osb,
1241                            u32 bits_wanted,
1242                            struct ocfs2_alloc_context **ac)
1243 {
1244         return ocfs2_reserve_clusters_with_limit(osb, bits_wanted, 0,
1245                                                  ALLOC_NEW_GROUP, ac);
1246 }
1247
1248 /*
1249  * More or less lifted from ext3. I'll leave their description below:
1250  *
1251  * "For ext3 allocations, we must not reuse any blocks which are
1252  * allocated in the bitmap buffer's "last committed data" copy.  This
1253  * prevents deletes from freeing up the page for reuse until we have
1254  * committed the delete transaction.
1255  *
1256  * If we didn't do this, then deleting something and reallocating it as
1257  * data would allow the old block to be overwritten before the
1258  * transaction committed (because we force data to disk before commit).
1259  * This would lead to corruption if we crashed between overwriting the
1260  * data and committing the delete.
1261  *
1262  * @@@ We may want to make this allocation behaviour conditional on
1263  * data-writes at some point, and disable it for metadata allocations or
1264  * sync-data inodes."
1265  *
1266  * Note: OCFS2 already does this differently for metadata vs data
1267  * allocations, as those bitmaps are separate and undo access is never
1268  * called on a metadata group descriptor.
1269  */
1270 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
1271                                          int nr)
1272 {
1273         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1274         int ret;
1275
1276         if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
1277                 return 0;
1278
1279         if (!buffer_jbd(bg_bh))
1280                 return 1;
1281
1282         jbd_lock_bh_state(bg_bh);
1283         bg = (struct ocfs2_group_desc *) bh2jh(bg_bh)->b_committed_data;
1284         if (bg)
1285                 ret = !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
1286         else
1287                 ret = 1;
1288         jbd_unlock_bh_state(bg_bh);
1289
1290         return ret;
1291 }
1292
1293 static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
1294                                              struct buffer_head *bg_bh,
1295                                              unsigned int bits_wanted,
1296                                              unsigned int total_bits,
1297                                              struct ocfs2_suballoc_result *res)
1298 {
1299         void *bitmap;
1300         u16 best_offset, best_size;
1301         int offset, start, found, status = 0;
1302         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1303
1304         /* Callers got this descriptor from
1305          * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1306         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1307
1308         found = start = best_offset = best_size = 0;
1309         bitmap = bg->bg_bitmap;
1310
1311         while((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) != -1) {
1312                 if (offset == total_bits)
1313                         break;
1314
1315                 if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
1316                         /* We found a zero, but we can't use it as it
1317                          * hasn't been put to disk yet! */
1318                         found = 0;
1319                         start = offset + 1;
1320                 } else if (offset == start) {
1321                         /* we found a zero */
1322                         found++;
1323                         /* move start to the next bit to test */
1324                         start++;
1325                 } else {
1326                         /* got a zero after some ones */
1327                         found = 1;
1328                         start = offset + 1;
1329                 }
1330                 if (found > best_size) {
1331                         best_size = found;
1332                         best_offset = start - found;
1333                 }
1334                 /* we got everything we needed */
1335                 if (found == bits_wanted) {
1336                         /* mlog(0, "Found it all!\n"); */
1337                         break;
1338                 }
1339         }
1340
1341         if (best_size) {
1342                 res->sr_bit_offset = best_offset;
1343                 res->sr_bits = best_size;
1344         } else {
1345                 status = -ENOSPC;
1346                 /* No error log here -- see the comment above
1347                  * ocfs2_test_bg_bit_allocatable */
1348         }
1349
1350         return status;
1351 }
1352
1353 int ocfs2_block_group_set_bits(handle_t *handle,
1354                                              struct inode *alloc_inode,
1355                                              struct ocfs2_group_desc *bg,
1356                                              struct buffer_head *group_bh,
1357                                              unsigned int bit_off,
1358                                              unsigned int num_bits)
1359 {
1360         int status;
1361         void *bitmap = bg->bg_bitmap;
1362         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1363
1364         /* All callers get the descriptor via
1365          * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1366         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1367         BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
1368
1369         trace_ocfs2_block_group_set_bits(bit_off, num_bits);
1370
1371         if (ocfs2_is_cluster_bitmap(alloc_inode))
1372                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1373
1374         status = ocfs2_journal_access_gd(handle,
1375                                          INODE_CACHE(alloc_inode),
1376                                          group_bh,
1377                                          journal_type);
1378         if (status < 0) {
1379                 mlog_errno(status);
1380                 goto bail;
1381         }
1382
1383         le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
1384         if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
1385                 return ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit count %u but claims %u are freed. num_bits %d\n",
1386                                    (unsigned long long)le64_to_cpu(bg->bg_blkno),
1387                                    le16_to_cpu(bg->bg_bits),
1388                                    le16_to_cpu(bg->bg_free_bits_count),
1389                                    num_bits);
1390         }
1391         while(num_bits--)
1392                 ocfs2_set_bit(bit_off++, bitmap);
1393
1394         ocfs2_journal_dirty(handle, group_bh);
1395
1396 bail:
1397         return status;
1398 }
1399
1400 /* find the one with the most empty bits */
1401 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
1402 {
1403         u16 curr, best;
1404
1405         BUG_ON(!cl->cl_next_free_rec);
1406
1407         best = curr = 0;
1408         while (curr < le16_to_cpu(cl->cl_next_free_rec)) {
1409                 if (le32_to_cpu(cl->cl_recs[curr].c_free) >
1410                     le32_to_cpu(cl->cl_recs[best].c_free))
1411                         best = curr;
1412                 curr++;
1413         }
1414
1415         BUG_ON(best >= le16_to_cpu(cl->cl_next_free_rec));
1416         return best;
1417 }
1418
1419 static int ocfs2_relink_block_group(handle_t *handle,
1420                                     struct inode *alloc_inode,
1421                                     struct buffer_head *fe_bh,
1422                                     struct buffer_head *bg_bh,
1423                                     struct buffer_head *prev_bg_bh,
1424                                     u16 chain)
1425 {
1426         int status;
1427         /* there is a really tiny chance the journal calls could fail,
1428          * but we wouldn't want inconsistent blocks in *any* case. */
1429         u64 bg_ptr, prev_bg_ptr;
1430         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
1431         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1432         struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
1433
1434         /* The caller got these descriptors from
1435          * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1436         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1437         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(prev_bg));
1438
1439         trace_ocfs2_relink_block_group(
1440                 (unsigned long long)le64_to_cpu(fe->i_blkno), chain,
1441                 (unsigned long long)le64_to_cpu(bg->bg_blkno),
1442                 (unsigned long long)le64_to_cpu(prev_bg->bg_blkno));
1443
1444         bg_ptr = le64_to_cpu(bg->bg_next_group);
1445         prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
1446
1447         status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1448                                          prev_bg_bh,
1449                                          OCFS2_JOURNAL_ACCESS_WRITE);
1450         if (status < 0)
1451                 goto out;
1452
1453         prev_bg->bg_next_group = bg->bg_next_group;
1454         ocfs2_journal_dirty(handle, prev_bg_bh);
1455
1456         status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1457                                          bg_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1458         if (status < 0)
1459                 goto out_rollback_prev_bg;
1460
1461         bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
1462         ocfs2_journal_dirty(handle, bg_bh);
1463
1464         status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
1465                                          fe_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1466         if (status < 0)
1467                 goto out_rollback_bg;
1468
1469         fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
1470         ocfs2_journal_dirty(handle, fe_bh);
1471
1472 out:
1473         if (status < 0)
1474                 mlog_errno(status);
1475         return status;
1476
1477 out_rollback_bg:
1478         bg->bg_next_group = cpu_to_le64(bg_ptr);
1479 out_rollback_prev_bg:
1480         prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
1481         goto out;
1482 }
1483
1484 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
1485                                                      u32 wanted)
1486 {
1487         return le16_to_cpu(bg->bg_free_bits_count) > wanted;
1488 }
1489
1490 /* return 0 on success, -ENOSPC to keep searching and any other < 0
1491  * value on error. */
1492 static int ocfs2_cluster_group_search(struct inode *inode,
1493                                       struct buffer_head *group_bh,
1494                                       u32 bits_wanted, u32 min_bits,
1495                                       u64 max_block,
1496                                       struct ocfs2_suballoc_result *res)
1497 {
1498         int search = -ENOSPC;
1499         int ret;
1500         u64 blkoff;
1501         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
1502         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1503         unsigned int max_bits, gd_cluster_off;
1504
1505         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1506
1507         if (gd->bg_free_bits_count) {
1508                 max_bits = le16_to_cpu(gd->bg_bits);
1509
1510                 /* Tail groups in cluster bitmaps which aren't cpg
1511                  * aligned are prone to partial extension by a failed
1512                  * fs resize. If the file system resize never got to
1513                  * update the dinode cluster count, then we don't want
1514                  * to trust any clusters past it, regardless of what
1515                  * the group descriptor says. */
1516                 gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
1517                                                           le64_to_cpu(gd->bg_blkno));
1518                 if ((gd_cluster_off + max_bits) >
1519                     OCFS2_I(inode)->ip_clusters) {
1520                         max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
1521                         trace_ocfs2_cluster_group_search_wrong_max_bits(
1522                                 (unsigned long long)le64_to_cpu(gd->bg_blkno),
1523                                 le16_to_cpu(gd->bg_bits),
1524                                 OCFS2_I(inode)->ip_clusters, max_bits);
1525                 }
1526
1527                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1528                                                         group_bh, bits_wanted,
1529                                                         max_bits, res);
1530                 if (ret)
1531                         return ret;
1532
1533                 if (max_block) {
1534                         blkoff = ocfs2_clusters_to_blocks(inode->i_sb,
1535                                                           gd_cluster_off +
1536                                                           res->sr_bit_offset +
1537                                                           res->sr_bits);
1538                         trace_ocfs2_cluster_group_search_max_block(
1539                                 (unsigned long long)blkoff,
1540                                 (unsigned long long)max_block);
1541                         if (blkoff > max_block)
1542                                 return -ENOSPC;
1543                 }
1544
1545                 /* ocfs2_block_group_find_clear_bits() might
1546                  * return success, but we still want to return
1547                  * -ENOSPC unless it found the minimum number
1548                  * of bits. */
1549                 if (min_bits <= res->sr_bits)
1550                         search = 0; /* success */
1551                 else if (res->sr_bits) {
1552                         /*
1553                          * Don't show bits which we'll be returning
1554                          * for allocation to the local alloc bitmap.
1555                          */
1556                         ocfs2_local_alloc_seen_free_bits(osb, res->sr_bits);
1557                 }
1558         }
1559
1560         return search;
1561 }
1562
1563 static int ocfs2_block_group_search(struct inode *inode,
1564                                     struct buffer_head *group_bh,
1565                                     u32 bits_wanted, u32 min_bits,
1566                                     u64 max_block,
1567                                     struct ocfs2_suballoc_result *res)
1568 {
1569         int ret = -ENOSPC;
1570         u64 blkoff;
1571         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
1572
1573         BUG_ON(min_bits != 1);
1574         BUG_ON(ocfs2_is_cluster_bitmap(inode));
1575
1576         if (bg->bg_free_bits_count) {
1577                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1578                                                         group_bh, bits_wanted,
1579                                                         le16_to_cpu(bg->bg_bits),
1580                                                         res);
1581                 if (!ret && max_block) {
1582                         blkoff = le64_to_cpu(bg->bg_blkno) +
1583                                 res->sr_bit_offset + res->sr_bits;
1584                         trace_ocfs2_block_group_search_max_block(
1585                                 (unsigned long long)blkoff,
1586                                 (unsigned long long)max_block);
1587                         if (blkoff > max_block)
1588                                 ret = -ENOSPC;
1589                 }
1590         }
1591
1592         return ret;
1593 }
1594
1595 int ocfs2_alloc_dinode_update_counts(struct inode *inode,
1596                                        handle_t *handle,
1597                                        struct buffer_head *di_bh,
1598                                        u32 num_bits,
1599                                        u16 chain)
1600 {
1601         int ret;
1602         u32 tmp_used;
1603         struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1604         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &di->id2.i_chain;
1605
1606         ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
1607                                       OCFS2_JOURNAL_ACCESS_WRITE);
1608         if (ret < 0) {
1609                 mlog_errno(ret);
1610                 goto out;
1611         }
1612
1613         tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1614         di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
1615         le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
1616         ocfs2_journal_dirty(handle, di_bh);
1617
1618 out:
1619         return ret;
1620 }
1621
1622 void ocfs2_rollback_alloc_dinode_counts(struct inode *inode,
1623                                        struct buffer_head *di_bh,
1624                                        u32 num_bits,
1625                                        u16 chain)
1626 {
1627         u32 tmp_used;
1628         struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1629         struct ocfs2_chain_list *cl;
1630
1631         cl = (struct ocfs2_chain_list *)&di->id2.i_chain;
1632         tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1633         di->id1.bitmap1.i_used = cpu_to_le32(tmp_used - num_bits);
1634         le32_add_cpu(&cl->cl_recs[chain].c_free, num_bits);
1635 }
1636
1637 static int ocfs2_bg_discontig_fix_by_rec(struct ocfs2_suballoc_result *res,
1638                                          struct ocfs2_extent_rec *rec,
1639                                          struct ocfs2_chain_list *cl)
1640 {
1641         unsigned int bpc = le16_to_cpu(cl->cl_bpc);
1642         unsigned int bitoff = le32_to_cpu(rec->e_cpos) * bpc;
1643         unsigned int bitcount = le16_to_cpu(rec->e_leaf_clusters) * bpc;
1644
1645         if (res->sr_bit_offset < bitoff)
1646                 return 0;
1647         if (res->sr_bit_offset >= (bitoff + bitcount))
1648                 return 0;
1649         res->sr_blkno = le64_to_cpu(rec->e_blkno) +
1650                 (res->sr_bit_offset - bitoff);
1651         if ((res->sr_bit_offset + res->sr_bits) > (bitoff + bitcount))
1652                 res->sr_bits = (bitoff + bitcount) - res->sr_bit_offset;
1653         return 1;
1654 }
1655
1656 static void ocfs2_bg_discontig_fix_result(struct ocfs2_alloc_context *ac,
1657                                           struct ocfs2_group_desc *bg,
1658                                           struct ocfs2_suballoc_result *res)
1659 {
1660         int i;
1661         u64 bg_blkno = res->sr_bg_blkno;  /* Save off */
1662         struct ocfs2_extent_rec *rec;
1663         struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1664         struct ocfs2_chain_list *cl = &di->id2.i_chain;
1665
1666         if (ocfs2_is_cluster_bitmap(ac->ac_inode)) {
1667                 res->sr_blkno = 0;
1668                 return;
1669         }
1670
1671         res->sr_blkno = res->sr_bg_blkno + res->sr_bit_offset;
1672         res->sr_bg_blkno = 0;  /* Clear it for contig block groups */
1673         if (!ocfs2_supports_discontig_bg(OCFS2_SB(ac->ac_inode->i_sb)) ||
1674             !bg->bg_list.l_next_free_rec)
1675                 return;
1676
1677         for (i = 0; i < le16_to_cpu(bg->bg_list.l_next_free_rec); i++) {
1678                 rec = &bg->bg_list.l_recs[i];
1679                 if (ocfs2_bg_discontig_fix_by_rec(res, rec, cl)) {
1680                         res->sr_bg_blkno = bg_blkno;  /* Restore */
1681                         break;
1682                 }
1683         }
1684 }
1685
1686 static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
1687                                   handle_t *handle,
1688                                   u32 bits_wanted,
1689                                   u32 min_bits,
1690                                   struct ocfs2_suballoc_result *res,
1691                                   u16 *bits_left)
1692 {
1693         int ret;
1694         struct buffer_head *group_bh = NULL;
1695         struct ocfs2_group_desc *gd;
1696         struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1697         struct inode *alloc_inode = ac->ac_inode;
1698
1699         ret = ocfs2_read_group_descriptor(alloc_inode, di,
1700                                           res->sr_bg_blkno, &group_bh);
1701         if (ret < 0) {
1702                 mlog_errno(ret);
1703                 return ret;
1704         }
1705
1706         gd = (struct ocfs2_group_desc *) group_bh->b_data;
1707         ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
1708                                   ac->ac_max_block, res);
1709         if (ret < 0) {
1710                 if (ret != -ENOSPC)
1711                         mlog_errno(ret);
1712                 goto out;
1713         }
1714
1715         if (!ret)
1716                 ocfs2_bg_discontig_fix_result(ac, gd, res);
1717
1718         /*
1719          * sr_bg_blkno might have been changed by
1720          * ocfs2_bg_discontig_fix_result
1721          */
1722         res->sr_bg_stable_blkno = group_bh->b_blocknr;
1723
1724         if (ac->ac_find_loc_only)
1725                 goto out_loc_only;
1726
1727         ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
1728                                                res->sr_bits,
1729                                                le16_to_cpu(gd->bg_chain));
1730         if (ret < 0) {
1731                 mlog_errno(ret);
1732                 goto out;
1733         }
1734
1735         ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
1736                                          res->sr_bit_offset, res->sr_bits);
1737         if (ret < 0) {
1738                 ocfs2_rollback_alloc_dinode_counts(alloc_inode, ac->ac_bh,
1739                                                res->sr_bits,
1740                                                le16_to_cpu(gd->bg_chain));
1741                 mlog_errno(ret);
1742         }
1743
1744 out_loc_only:
1745         *bits_left = le16_to_cpu(gd->bg_free_bits_count);
1746
1747 out:
1748         brelse(group_bh);
1749
1750         return ret;
1751 }
1752
1753 static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
1754                               handle_t *handle,
1755                               u32 bits_wanted,
1756                               u32 min_bits,
1757                               struct ocfs2_suballoc_result *res,
1758                               u16 *bits_left)
1759 {
1760         int status;
1761         u16 chain;
1762         u64 next_group;
1763         struct inode *alloc_inode = ac->ac_inode;
1764         struct buffer_head *group_bh = NULL;
1765         struct buffer_head *prev_group_bh = NULL;
1766         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1767         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1768         struct ocfs2_group_desc *bg;
1769
1770         chain = ac->ac_chain;
1771         trace_ocfs2_search_chain_begin(
1772                 (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
1773                 bits_wanted, chain);
1774
1775         status = ocfs2_read_group_descriptor(alloc_inode, fe,
1776                                              le64_to_cpu(cl->cl_recs[chain].c_blkno),
1777                                              &group_bh);
1778         if (status < 0) {
1779                 mlog_errno(status);
1780                 goto bail;
1781         }
1782         bg = (struct ocfs2_group_desc *) group_bh->b_data;
1783
1784         status = -ENOSPC;
1785         /* for now, the chain search is a bit simplistic. We just use
1786          * the 1st group with any empty bits. */
1787         while ((status = ac->ac_group_search(alloc_inode, group_bh,
1788                                              bits_wanted, min_bits,
1789                                              ac->ac_max_block,
1790                                              res)) == -ENOSPC) {
1791                 if (!bg->bg_next_group)
1792                         break;
1793
1794                 brelse(prev_group_bh);
1795                 prev_group_bh = NULL;
1796
1797                 next_group = le64_to_cpu(bg->bg_next_group);
1798                 prev_group_bh = group_bh;
1799                 group_bh = NULL;
1800                 status = ocfs2_read_group_descriptor(alloc_inode, fe,
1801                                                      next_group, &group_bh);
1802                 if (status < 0) {
1803                         mlog_errno(status);
1804                         goto bail;
1805                 }
1806                 bg = (struct ocfs2_group_desc *) group_bh->b_data;
1807         }
1808         if (status < 0) {
1809                 if (status != -ENOSPC)
1810                         mlog_errno(status);
1811                 goto bail;
1812         }
1813
1814         trace_ocfs2_search_chain_succ(
1815                 (unsigned long long)le64_to_cpu(bg->bg_blkno), res->sr_bits);
1816
1817         res->sr_bg_blkno = le64_to_cpu(bg->bg_blkno);
1818
1819         BUG_ON(res->sr_bits == 0);
1820         if (!status)
1821                 ocfs2_bg_discontig_fix_result(ac, bg, res);
1822
1823         /*
1824          * sr_bg_blkno might have been changed by
1825          * ocfs2_bg_discontig_fix_result
1826          */
1827         res->sr_bg_stable_blkno = group_bh->b_blocknr;
1828
1829         /*
1830          * Keep track of previous block descriptor read. When
1831          * we find a target, if we have read more than X
1832          * number of descriptors, and the target is reasonably
1833          * empty, relink him to top of his chain.
1834          *
1835          * We've read 0 extra blocks and only send one more to
1836          * the transaction, yet the next guy to search has a
1837          * much easier time.
1838          *
1839          * Do this *after* figuring out how many bits we're taking out
1840          * of our target group.
1841          */
1842         if (!ac->ac_disable_chain_relink &&
1843             (prev_group_bh) &&
1844             (ocfs2_block_group_reasonably_empty(bg, res->sr_bits))) {
1845                 status = ocfs2_relink_block_group(handle, alloc_inode,
1846                                                   ac->ac_bh, group_bh,
1847                                                   prev_group_bh, chain);
1848                 if (status < 0) {
1849                         mlog_errno(status);
1850                         goto bail;
1851                 }
1852         }
1853
1854         if (ac->ac_find_loc_only)
1855                 goto out_loc_only;
1856
1857         status = ocfs2_alloc_dinode_update_counts(alloc_inode, handle,
1858                                                   ac->ac_bh, res->sr_bits,
1859                                                   chain);
1860         if (status) {
1861                 mlog_errno(status);
1862                 goto bail;
1863         }
1864
1865         status = ocfs2_block_group_set_bits(handle,
1866                                             alloc_inode,
1867                                             bg,
1868                                             group_bh,
1869                                             res->sr_bit_offset,
1870                                             res->sr_bits);
1871         if (status < 0) {
1872                 ocfs2_rollback_alloc_dinode_counts(alloc_inode,
1873                                         ac->ac_bh, res->sr_bits, chain);
1874                 mlog_errno(status);
1875                 goto bail;
1876         }
1877
1878         trace_ocfs2_search_chain_end(
1879                         (unsigned long long)le64_to_cpu(fe->i_blkno),
1880                         res->sr_bits);
1881
1882 out_loc_only:
1883         *bits_left = le16_to_cpu(bg->bg_free_bits_count);
1884 bail:
1885         brelse(group_bh);
1886         brelse(prev_group_bh);
1887
1888         if (status)
1889                 mlog_errno(status);
1890         return status;
1891 }
1892
1893 /* will give out up to bits_wanted contiguous bits. */
1894 static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
1895                                      handle_t *handle,
1896                                      u32 bits_wanted,
1897                                      u32 min_bits,
1898                                      struct ocfs2_suballoc_result *res)
1899 {
1900         int status;
1901         u16 victim, i;
1902         u16 bits_left = 0;
1903         u64 hint = ac->ac_last_group;
1904         struct ocfs2_chain_list *cl;
1905         struct ocfs2_dinode *fe;
1906
1907         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1908         BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1909         BUG_ON(!ac->ac_bh);
1910
1911         fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1912
1913         /* The bh was validated by the inode read during
1914          * ocfs2_reserve_suballoc_bits().  Any corruption is a code bug. */
1915         BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
1916
1917         if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1918             le32_to_cpu(fe->id1.bitmap1.i_total)) {
1919                 status = ocfs2_error(ac->ac_inode->i_sb,
1920                                      "Chain allocator dinode %llu has %u used bits but only %u total\n",
1921                                      (unsigned long long)le64_to_cpu(fe->i_blkno),
1922                                      le32_to_cpu(fe->id1.bitmap1.i_used),
1923                                      le32_to_cpu(fe->id1.bitmap1.i_total));
1924                 goto bail;
1925         }
1926
1927         res->sr_bg_blkno = hint;
1928         if (res->sr_bg_blkno) {
1929                 /* Attempt to short-circuit the usual search mechanism
1930                  * by jumping straight to the most recently used
1931                  * allocation group. This helps us maintain some
1932                  * contiguousness across allocations. */
1933                 status = ocfs2_search_one_group(ac, handle, bits_wanted,
1934                                                 min_bits, res, &bits_left);
1935                 if (!status)
1936                         goto set_hint;
1937                 if (status < 0 && status != -ENOSPC) {
1938                         mlog_errno(status);
1939                         goto bail;
1940                 }
1941         }
1942
1943         cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1944
1945         victim = ocfs2_find_victim_chain(cl);
1946         ac->ac_chain = victim;
1947
1948         status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1949                                     res, &bits_left);
1950         if (!status) {
1951                 if (ocfs2_is_cluster_bitmap(ac->ac_inode))
1952                         hint = res->sr_bg_blkno;
1953                 else
1954                         hint = ocfs2_group_from_res(res);
1955                 goto set_hint;
1956         }
1957         if (status < 0 && status != -ENOSPC) {
1958                 mlog_errno(status);
1959                 goto bail;
1960         }
1961
1962         trace_ocfs2_claim_suballoc_bits(victim);
1963
1964         /* If we didn't pick a good victim, then just default to
1965          * searching each chain in order. Don't allow chain relinking
1966          * because we only calculate enough journal credits for one
1967          * relink per alloc. */
1968         ac->ac_disable_chain_relink = 1;
1969         for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
1970                 if (i == victim)
1971                         continue;
1972                 if (!cl->cl_recs[i].c_free)
1973                         continue;
1974
1975                 ac->ac_chain = i;
1976                 status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1977                                             res, &bits_left);
1978                 if (!status) {
1979                         hint = ocfs2_group_from_res(res);
1980                         break;
1981                 }
1982                 if (status < 0 && status != -ENOSPC) {
1983                         mlog_errno(status);
1984                         goto bail;
1985                 }
1986         }
1987
1988 set_hint:
1989         if (status != -ENOSPC) {
1990                 /* If the next search of this group is not likely to
1991                  * yield a suitable extent, then we reset the last
1992                  * group hint so as to not waste a disk read */
1993                 if (bits_left < min_bits)
1994                         ac->ac_last_group = 0;
1995                 else
1996                         ac->ac_last_group = hint;
1997         }
1998
1999 bail:
2000         if (status)
2001                 mlog_errno(status);
2002         return status;
2003 }
2004
2005 int ocfs2_claim_metadata(handle_t *handle,
2006                          struct ocfs2_alloc_context *ac,
2007                          u32 bits_wanted,
2008                          u64 *suballoc_loc,
2009                          u16 *suballoc_bit_start,
2010                          unsigned int *num_bits,
2011                          u64 *blkno_start)
2012 {
2013         int status;
2014         struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
2015
2016         BUG_ON(!ac);
2017         BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
2018         BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
2019
2020         status = ocfs2_claim_suballoc_bits(ac,
2021                                            handle,
2022                                            bits_wanted,
2023                                            1,
2024                                            &res);
2025         if (status < 0) {
2026                 mlog_errno(status);
2027                 goto bail;
2028         }
2029         atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2030
2031         *suballoc_loc = res.sr_bg_blkno;
2032         *suballoc_bit_start = res.sr_bit_offset;
2033         *blkno_start = res.sr_blkno;
2034         ac->ac_bits_given += res.sr_bits;
2035         *num_bits = res.sr_bits;
2036         status = 0;
2037 bail:
2038         if (status)
2039                 mlog_errno(status);
2040         return status;
2041 }
2042
2043 static void ocfs2_init_inode_ac_group(struct inode *dir,
2044                                       struct buffer_head *parent_di_bh,
2045                                       struct ocfs2_alloc_context *ac)
2046 {
2047         struct ocfs2_dinode *di = (struct ocfs2_dinode *)parent_di_bh->b_data;
2048         /*
2049          * Try to allocate inodes from some specific group.
2050          *
2051          * If the parent dir has recorded the last group used in allocation,
2052          * cool, use it. Otherwise if we try to allocate new inode from the
2053          * same slot the parent dir belongs to, use the same chunk.
2054          *
2055          * We are very careful here to avoid the mistake of setting
2056          * ac_last_group to a group descriptor from a different (unlocked) slot.
2057          */
2058         if (OCFS2_I(dir)->ip_last_used_group &&
2059             OCFS2_I(dir)->ip_last_used_slot == ac->ac_alloc_slot)
2060                 ac->ac_last_group = OCFS2_I(dir)->ip_last_used_group;
2061         else if (le16_to_cpu(di->i_suballoc_slot) == ac->ac_alloc_slot) {
2062                 if (di->i_suballoc_loc)
2063                         ac->ac_last_group = le64_to_cpu(di->i_suballoc_loc);
2064                 else
2065                         ac->ac_last_group = ocfs2_which_suballoc_group(
2066                                         le64_to_cpu(di->i_blkno),
2067                                         le16_to_cpu(di->i_suballoc_bit));
2068         }
2069 }
2070
2071 static inline void ocfs2_save_inode_ac_group(struct inode *dir,
2072                                              struct ocfs2_alloc_context *ac)
2073 {
2074         OCFS2_I(dir)->ip_last_used_group = ac->ac_last_group;
2075         OCFS2_I(dir)->ip_last_used_slot = ac->ac_alloc_slot;
2076 }
2077
2078 int ocfs2_find_new_inode_loc(struct inode *dir,
2079                              struct buffer_head *parent_fe_bh,
2080                              struct ocfs2_alloc_context *ac,
2081                              u64 *fe_blkno)
2082 {
2083         int ret;
2084         handle_t *handle = NULL;
2085         struct ocfs2_suballoc_result *res;
2086
2087         BUG_ON(!ac);
2088         BUG_ON(ac->ac_bits_given != 0);
2089         BUG_ON(ac->ac_bits_wanted != 1);
2090         BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2091
2092         res = kzalloc(sizeof(*res), GFP_NOFS);
2093         if (res == NULL) {
2094                 ret = -ENOMEM;
2095                 mlog_errno(ret);
2096                 goto out;
2097         }
2098
2099         ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2100
2101         /*
2102          * The handle started here is for chain relink. Alternatively,
2103          * we could just disable relink for these calls.
2104          */
2105         handle = ocfs2_start_trans(OCFS2_SB(dir->i_sb), OCFS2_SUBALLOC_ALLOC);
2106         if (IS_ERR(handle)) {
2107                 ret = PTR_ERR(handle);
2108                 handle = NULL;
2109                 mlog_errno(ret);
2110                 goto out;
2111         }
2112
2113         /*
2114          * This will instruct ocfs2_claim_suballoc_bits and
2115          * ocfs2_search_one_group to search but save actual allocation
2116          * for later.
2117          */
2118         ac->ac_find_loc_only = 1;
2119
2120         ret = ocfs2_claim_suballoc_bits(ac, handle, 1, 1, res);
2121         if (ret < 0) {
2122                 mlog_errno(ret);
2123                 goto out;
2124         }
2125
2126         ac->ac_find_loc_priv = res;
2127         *fe_blkno = res->sr_blkno;
2128         ocfs2_update_inode_fsync_trans(handle, dir, 0);
2129 out:
2130         if (handle)
2131                 ocfs2_commit_trans(OCFS2_SB(dir->i_sb), handle);
2132
2133         if (ret)
2134                 kfree(res);
2135
2136         return ret;
2137 }
2138
2139 int ocfs2_claim_new_inode_at_loc(handle_t *handle,
2140                                  struct inode *dir,
2141                                  struct ocfs2_alloc_context *ac,
2142                                  u64 *suballoc_loc,
2143                                  u16 *suballoc_bit,
2144                                  u64 di_blkno)
2145 {
2146         int ret;
2147         u16 chain;
2148         struct ocfs2_suballoc_result *res = ac->ac_find_loc_priv;
2149         struct buffer_head *bg_bh = NULL;
2150         struct ocfs2_group_desc *bg;
2151         struct ocfs2_dinode *di = (struct ocfs2_dinode *) ac->ac_bh->b_data;
2152
2153         /*
2154          * Since di_blkno is being passed back in, we check for any
2155          * inconsistencies which may have happened between
2156          * calls. These are code bugs as di_blkno is not expected to
2157          * change once returned from ocfs2_find_new_inode_loc()
2158          */
2159         BUG_ON(res->sr_blkno != di_blkno);
2160
2161         ret = ocfs2_read_group_descriptor(ac->ac_inode, di,
2162                                           res->sr_bg_stable_blkno, &bg_bh);
2163         if (ret) {
2164                 mlog_errno(ret);
2165                 goto out;
2166         }
2167
2168         bg = (struct ocfs2_group_desc *) bg_bh->b_data;
2169         chain = le16_to_cpu(bg->bg_chain);
2170
2171         ret = ocfs2_alloc_dinode_update_counts(ac->ac_inode, handle,
2172                                                ac->ac_bh, res->sr_bits,
2173                                                chain);
2174         if (ret) {
2175                 mlog_errno(ret);
2176                 goto out;
2177         }
2178
2179         ret = ocfs2_block_group_set_bits(handle,
2180                                          ac->ac_inode,
2181                                          bg,
2182                                          bg_bh,
2183                                          res->sr_bit_offset,
2184                                          res->sr_bits);
2185         if (ret < 0) {
2186                 ocfs2_rollback_alloc_dinode_counts(ac->ac_inode,
2187                                                ac->ac_bh, res->sr_bits, chain);
2188                 mlog_errno(ret);
2189                 goto out;
2190         }
2191
2192         trace_ocfs2_claim_new_inode_at_loc((unsigned long long)di_blkno,
2193                                            res->sr_bits);
2194
2195         atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2196
2197         BUG_ON(res->sr_bits != 1);
2198
2199         *suballoc_loc = res->sr_bg_blkno;
2200         *suballoc_bit = res->sr_bit_offset;
2201         ac->ac_bits_given++;
2202         ocfs2_save_inode_ac_group(dir, ac);
2203
2204 out:
2205         brelse(bg_bh);
2206
2207         return ret;
2208 }
2209
2210 int ocfs2_claim_new_inode(handle_t *handle,
2211                           struct inode *dir,
2212                           struct buffer_head *parent_fe_bh,
2213                           struct ocfs2_alloc_context *ac,
2214                           u64 *suballoc_loc,
2215                           u16 *suballoc_bit,
2216                           u64 *fe_blkno)
2217 {
2218         int status;
2219         struct ocfs2_suballoc_result res;
2220
2221         BUG_ON(!ac);
2222         BUG_ON(ac->ac_bits_given != 0);
2223         BUG_ON(ac->ac_bits_wanted != 1);
2224         BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2225
2226         ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2227
2228         status = ocfs2_claim_suballoc_bits(ac,
2229                                            handle,
2230                                            1,
2231                                            1,
2232                                            &res);
2233         if (status < 0) {
2234                 mlog_errno(status);
2235                 goto bail;
2236         }
2237         atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2238
2239         BUG_ON(res.sr_bits != 1);
2240
2241         *suballoc_loc = res.sr_bg_blkno;
2242         *suballoc_bit = res.sr_bit_offset;
2243         *fe_blkno = res.sr_blkno;
2244         ac->ac_bits_given++;
2245         ocfs2_save_inode_ac_group(dir, ac);
2246         status = 0;
2247 bail:
2248         if (status)
2249                 mlog_errno(status);
2250         return status;
2251 }
2252
2253 /* translate a group desc. blkno and it's bitmap offset into
2254  * disk cluster offset. */
2255 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
2256                                                    u64 bg_blkno,
2257                                                    u16 bg_bit_off)
2258 {
2259         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2260         u32 cluster = 0;
2261
2262         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2263
2264         if (bg_blkno != osb->first_cluster_group_blkno)
2265                 cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
2266         cluster += (u32) bg_bit_off;
2267         return cluster;
2268 }
2269
2270 /* given a cluster offset, calculate which block group it belongs to
2271  * and return that block offset. */
2272 u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster)
2273 {
2274         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2275         u32 group_no;
2276
2277         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2278
2279         group_no = cluster / osb->bitmap_cpg;
2280         if (!group_no)
2281                 return osb->first_cluster_group_blkno;
2282         return ocfs2_clusters_to_blocks(inode->i_sb,
2283                                         group_no * osb->bitmap_cpg);
2284 }
2285
2286 /* given the block number of a cluster start, calculate which cluster
2287  * group and descriptor bitmap offset that corresponds to. */
2288 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
2289                                                 u64 data_blkno,
2290                                                 u64 *bg_blkno,
2291                                                 u16 *bg_bit_off)
2292 {
2293         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2294         u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
2295
2296         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2297
2298         *bg_blkno = ocfs2_which_cluster_group(inode,
2299                                               data_cluster);
2300
2301         if (*bg_blkno == osb->first_cluster_group_blkno)
2302                 *bg_bit_off = (u16) data_cluster;
2303         else
2304                 *bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
2305                                                              data_blkno - *bg_blkno);
2306 }
2307
2308 /*
2309  * min_bits - minimum contiguous chunk from this total allocation we
2310  * can handle. set to what we asked for originally for a full
2311  * contig. allocation, set to '1' to indicate we can deal with extents
2312  * of any size.
2313  */
2314 int __ocfs2_claim_clusters(handle_t *handle,
2315                            struct ocfs2_alloc_context *ac,
2316                            u32 min_clusters,
2317                            u32 max_clusters,
2318                            u32 *cluster_start,
2319                            u32 *num_clusters)
2320 {
2321         int status;
2322         unsigned int bits_wanted = max_clusters;
2323         struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
2324         struct ocfs2_super *osb = OCFS2_SB(ac->ac_inode->i_sb);
2325
2326         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
2327
2328         BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
2329                && ac->ac_which != OCFS2_AC_USE_MAIN);
2330
2331         if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
2332                 WARN_ON(min_clusters > 1);
2333
2334                 status = ocfs2_claim_local_alloc_bits(osb,
2335                                                       handle,
2336                                                       ac,
2337                                                       bits_wanted,
2338                                                       cluster_start,
2339                                                       num_clusters);
2340                 if (!status)
2341                         atomic_inc(&osb->alloc_stats.local_data);
2342         } else {
2343                 if (min_clusters > (osb->bitmap_cpg - 1)) {
2344                         /* The only paths asking for contiguousness
2345                          * should know about this already. */
2346                         mlog(ML_ERROR, "minimum allocation requested %u exceeds "
2347                              "group bitmap size %u!\n", min_clusters,
2348                              osb->bitmap_cpg);
2349                         status = -ENOSPC;
2350                         goto bail;
2351                 }
2352                 /* clamp the current request down to a realistic size. */
2353                 if (bits_wanted > (osb->bitmap_cpg - 1))
2354                         bits_wanted = osb->bitmap_cpg - 1;
2355
2356                 status = ocfs2_claim_suballoc_bits(ac,
2357                                                    handle,
2358                                                    bits_wanted,
2359                                                    min_clusters,
2360                                                    &res);
2361                 if (!status) {
2362                         BUG_ON(res.sr_blkno); /* cluster alloc can't set */
2363                         *cluster_start =
2364                                 ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
2365                                                                  res.sr_bg_blkno,
2366                                                                  res.sr_bit_offset);
2367                         atomic_inc(&osb->alloc_stats.bitmap_data);
2368                         *num_clusters = res.sr_bits;
2369                 }
2370         }
2371         if (status < 0) {
2372                 if (status != -ENOSPC)
2373                         mlog_errno(status);
2374                 goto bail;
2375         }
2376
2377         ac->ac_bits_given += *num_clusters;
2378
2379 bail:
2380         if (status)
2381                 mlog_errno(status);
2382         return status;
2383 }
2384
2385 int ocfs2_claim_clusters(handle_t *handle,
2386                          struct ocfs2_alloc_context *ac,
2387                          u32 min_clusters,
2388                          u32 *cluster_start,
2389                          u32 *num_clusters)
2390 {
2391         unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
2392
2393         return __ocfs2_claim_clusters(handle, ac, min_clusters,
2394                                       bits_wanted, cluster_start, num_clusters);
2395 }
2396
2397 static int ocfs2_block_group_clear_bits(handle_t *handle,
2398                                         struct inode *alloc_inode,
2399                                         struct ocfs2_group_desc *bg,
2400                                         struct buffer_head *group_bh,
2401                                         unsigned int bit_off,
2402                                         unsigned int num_bits,
2403                                         void (*undo_fn)(unsigned int bit,
2404                                                         unsigned long *bmap))
2405 {
2406         int status;
2407         unsigned int tmp;
2408         struct ocfs2_group_desc *undo_bg = NULL;
2409
2410         /* The caller got this descriptor from
2411          * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
2412         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
2413
2414         trace_ocfs2_block_group_clear_bits(bit_off, num_bits);
2415
2416         BUG_ON(undo_fn && !ocfs2_is_cluster_bitmap(alloc_inode));
2417         status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
2418                                          group_bh,
2419                                          undo_fn ?
2420                                          OCFS2_JOURNAL_ACCESS_UNDO :
2421                                          OCFS2_JOURNAL_ACCESS_WRITE);
2422         if (status < 0) {
2423                 mlog_errno(status);
2424                 goto bail;
2425         }
2426
2427         if (undo_fn) {
2428                 jbd_lock_bh_state(group_bh);
2429                 undo_bg = (struct ocfs2_group_desc *)
2430                                         bh2jh(group_bh)->b_committed_data;
2431                 BUG_ON(!undo_bg);
2432         }
2433
2434         tmp = num_bits;
2435         while(tmp--) {
2436                 ocfs2_clear_bit((bit_off + tmp),
2437                                 (unsigned long *) bg->bg_bitmap);
2438                 if (undo_fn)
2439                         undo_fn(bit_off + tmp,
2440                                 (unsigned long *) undo_bg->bg_bitmap);
2441         }
2442         le16_add_cpu(&bg->bg_free_bits_count, num_bits);
2443         if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
2444                 return ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit count %u but claims %u are freed. num_bits %d\n",
2445                                    (unsigned long long)le64_to_cpu(bg->bg_blkno),
2446                                    le16_to_cpu(bg->bg_bits),
2447                                    le16_to_cpu(bg->bg_free_bits_count),
2448                                    num_bits);
2449         }
2450
2451         if (undo_fn)
2452                 jbd_unlock_bh_state(group_bh);
2453
2454         ocfs2_journal_dirty(handle, group_bh);
2455 bail:
2456         return status;
2457 }
2458
2459 /*
2460  * expects the suballoc inode to already be locked.
2461  */
2462 static int _ocfs2_free_suballoc_bits(handle_t *handle,
2463                                      struct inode *alloc_inode,
2464                                      struct buffer_head *alloc_bh,
2465                                      unsigned int start_bit,
2466                                      u64 bg_blkno,
2467                                      unsigned int count,
2468                                      void (*undo_fn)(unsigned int bit,
2469                                                      unsigned long *bitmap))
2470 {
2471         int status = 0;
2472         u32 tmp_used;
2473         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
2474         struct ocfs2_chain_list *cl = &fe->id2.i_chain;
2475         struct buffer_head *group_bh = NULL;
2476         struct ocfs2_group_desc *group;
2477
2478         /* The alloc_bh comes from ocfs2_free_dinode() or
2479          * ocfs2_free_clusters().  The callers have all locked the
2480          * allocator and gotten alloc_bh from the lock call.  This
2481          * validates the dinode buffer.  Any corruption that has happened
2482          * is a code bug. */
2483         BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
2484         BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
2485
2486         trace_ocfs2_free_suballoc_bits(
2487                 (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
2488                 (unsigned long long)bg_blkno,
2489                 start_bit, count);
2490
2491         status = ocfs2_read_group_descriptor(alloc_inode, fe, bg_blkno,
2492                                              &group_bh);
2493         if (status < 0) {
2494                 mlog_errno(status);
2495                 goto bail;
2496         }
2497         group = (struct ocfs2_group_desc *) group_bh->b_data;
2498
2499         BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
2500
2501         status = ocfs2_block_group_clear_bits(handle, alloc_inode,
2502                                               group, group_bh,
2503                                               start_bit, count, undo_fn);
2504         if (status < 0) {
2505                 mlog_errno(status);
2506                 goto bail;
2507         }
2508
2509         status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
2510                                          alloc_bh, OCFS2_JOURNAL_ACCESS_WRITE);
2511         if (status < 0) {
2512                 mlog_errno(status);
2513                 ocfs2_block_group_set_bits(handle, alloc_inode, group, group_bh,
2514                                 start_bit, count);
2515                 goto bail;
2516         }
2517
2518         le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
2519                      count);
2520         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
2521         fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
2522         ocfs2_journal_dirty(handle, alloc_bh);
2523
2524 bail:
2525         brelse(group_bh);
2526
2527         if (status)
2528                 mlog_errno(status);
2529         return status;
2530 }
2531
2532 int ocfs2_free_suballoc_bits(handle_t *handle,
2533                              struct inode *alloc_inode,
2534                              struct buffer_head *alloc_bh,
2535                              unsigned int start_bit,
2536                              u64 bg_blkno,
2537                              unsigned int count)
2538 {
2539         return _ocfs2_free_suballoc_bits(handle, alloc_inode, alloc_bh,
2540                                          start_bit, bg_blkno, count, NULL);
2541 }
2542
2543 int ocfs2_free_dinode(handle_t *handle,
2544                       struct inode *inode_alloc_inode,
2545                       struct buffer_head *inode_alloc_bh,
2546                       struct ocfs2_dinode *di)
2547 {
2548         u64 blk = le64_to_cpu(di->i_blkno);
2549         u16 bit = le16_to_cpu(di->i_suballoc_bit);
2550         u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
2551
2552         if (di->i_suballoc_loc)
2553                 bg_blkno = le64_to_cpu(di->i_suballoc_loc);
2554         return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
2555                                         inode_alloc_bh, bit, bg_blkno, 1);
2556 }
2557
2558 static int _ocfs2_free_clusters(handle_t *handle,
2559                                 struct inode *bitmap_inode,
2560                                 struct buffer_head *bitmap_bh,
2561                                 u64 start_blk,
2562                                 unsigned int num_clusters,
2563                                 void (*undo_fn)(unsigned int bit,
2564                                                 unsigned long *bitmap))
2565 {
2566         int status;
2567         u16 bg_start_bit;
2568         u64 bg_blkno;
2569         struct ocfs2_dinode *fe;
2570
2571         /* You can't ever have a contiguous set of clusters
2572          * bigger than a block group bitmap so we never have to worry
2573          * about looping on them.
2574          * This is expensive. We can safely remove once this stuff has
2575          * gotten tested really well. */
2576         BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb, ocfs2_blocks_to_clusters(bitmap_inode->i_sb, start_blk)));
2577
2578         fe = (struct ocfs2_dinode *) bitmap_bh->b_data;
2579
2580         ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
2581                                      &bg_start_bit);
2582
2583         trace_ocfs2_free_clusters((unsigned long long)bg_blkno,
2584                         (unsigned long long)start_blk,
2585                         bg_start_bit, num_clusters);
2586
2587         status = _ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
2588                                            bg_start_bit, bg_blkno,
2589                                            num_clusters, undo_fn);
2590         if (status < 0) {
2591                 mlog_errno(status);
2592                 goto out;
2593         }
2594
2595         ocfs2_local_alloc_seen_free_bits(OCFS2_SB(bitmap_inode->i_sb),
2596                                          num_clusters);
2597
2598 out:
2599         if (status)
2600                 mlog_errno(status);
2601         return status;
2602 }
2603
2604 int ocfs2_free_clusters(handle_t *handle,
2605                         struct inode *bitmap_inode,
2606                         struct buffer_head *bitmap_bh,
2607                         u64 start_blk,
2608                         unsigned int num_clusters)
2609 {
2610         return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2611                                     start_blk, num_clusters,
2612                                     _ocfs2_set_bit);
2613 }
2614
2615 /*
2616  * Give never-used clusters back to the global bitmap.  We don't need
2617  * to protect these bits in the undo buffer.
2618  */
2619 int ocfs2_release_clusters(handle_t *handle,
2620                            struct inode *bitmap_inode,
2621                            struct buffer_head *bitmap_bh,
2622                            u64 start_blk,
2623                            unsigned int num_clusters)
2624 {
2625         return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2626                                     start_blk, num_clusters,
2627                                     _ocfs2_clear_bit);
2628 }
2629
2630 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg)
2631 {
2632         printk("Block Group:\n");
2633         printk("bg_signature:       %s\n", bg->bg_signature);
2634         printk("bg_size:            %u\n", bg->bg_size);
2635         printk("bg_bits:            %u\n", bg->bg_bits);
2636         printk("bg_free_bits_count: %u\n", bg->bg_free_bits_count);
2637         printk("bg_chain:           %u\n", bg->bg_chain);
2638         printk("bg_generation:      %u\n", le32_to_cpu(bg->bg_generation));
2639         printk("bg_next_group:      %llu\n",
2640                (unsigned long long)bg->bg_next_group);
2641         printk("bg_parent_dinode:   %llu\n",
2642                (unsigned long long)bg->bg_parent_dinode);
2643         printk("bg_blkno:           %llu\n",
2644                (unsigned long long)bg->bg_blkno);
2645 }
2646
2647 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe)
2648 {
2649         int i;
2650
2651         printk("Suballoc Inode %llu:\n", (unsigned long long)fe->i_blkno);
2652         printk("i_signature:                  %s\n", fe->i_signature);
2653         printk("i_size:                       %llu\n",
2654                (unsigned long long)fe->i_size);
2655         printk("i_clusters:                   %u\n", fe->i_clusters);
2656         printk("i_generation:                 %u\n",
2657                le32_to_cpu(fe->i_generation));
2658         printk("id1.bitmap1.i_used:           %u\n",
2659                le32_to_cpu(fe->id1.bitmap1.i_used));
2660         printk("id1.bitmap1.i_total:          %u\n",
2661                le32_to_cpu(fe->id1.bitmap1.i_total));
2662         printk("id2.i_chain.cl_cpg:           %u\n", fe->id2.i_chain.cl_cpg);
2663         printk("id2.i_chain.cl_bpc:           %u\n", fe->id2.i_chain.cl_bpc);
2664         printk("id2.i_chain.cl_count:         %u\n", fe->id2.i_chain.cl_count);
2665         printk("id2.i_chain.cl_next_free_rec: %u\n",
2666                fe->id2.i_chain.cl_next_free_rec);
2667         for(i = 0; i < fe->id2.i_chain.cl_next_free_rec; i++) {
2668                 printk("fe->id2.i_chain.cl_recs[%d].c_free:  %u\n", i,
2669                        fe->id2.i_chain.cl_recs[i].c_free);
2670                 printk("fe->id2.i_chain.cl_recs[%d].c_total: %u\n", i,
2671                        fe->id2.i_chain.cl_recs[i].c_total);
2672                 printk("fe->id2.i_chain.cl_recs[%d].c_blkno: %llu\n", i,
2673                        (unsigned long long)fe->id2.i_chain.cl_recs[i].c_blkno);
2674         }
2675 }
2676
2677 /*
2678  * For a given allocation, determine which allocators will need to be
2679  * accessed, and lock them, reserving the appropriate number of bits.
2680  *
2681  * Sparse file systems call this from ocfs2_write_begin_nolock()
2682  * and ocfs2_allocate_unwritten_extents().
2683  *
2684  * File systems which don't support holes call this from
2685  * ocfs2_extend_allocation().
2686  */
2687 int ocfs2_lock_allocators(struct inode *inode,
2688                           struct ocfs2_extent_tree *et,
2689                           u32 clusters_to_add, u32 extents_to_split,
2690                           struct ocfs2_alloc_context **data_ac,
2691                           struct ocfs2_alloc_context **meta_ac)
2692 {
2693         int ret = 0, num_free_extents;
2694         unsigned int max_recs_needed = clusters_to_add + 2 * extents_to_split;
2695         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2696
2697         *meta_ac = NULL;
2698         if (data_ac)
2699                 *data_ac = NULL;
2700
2701         BUG_ON(clusters_to_add != 0 && data_ac == NULL);
2702
2703         num_free_extents = ocfs2_num_free_extents(osb, et);
2704         if (num_free_extents < 0) {
2705                 ret = num_free_extents;
2706                 mlog_errno(ret);
2707                 goto out;
2708         }
2709
2710         /*
2711          * Sparse allocation file systems need to be more conservative
2712          * with reserving room for expansion - the actual allocation
2713          * happens while we've got a journal handle open so re-taking
2714          * a cluster lock (because we ran out of room for another
2715          * extent) will violate ordering rules.
2716          *
2717          * Most of the time we'll only be seeing this 1 cluster at a time
2718          * anyway.
2719          *
2720          * Always lock for any unwritten extents - we might want to
2721          * add blocks during a split.
2722          */
2723         if (!num_free_extents ||
2724             (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed)) {
2725                 ret = ocfs2_reserve_new_metadata(osb, et->et_root_el, meta_ac);
2726                 if (ret < 0) {
2727                         if (ret != -ENOSPC)
2728                                 mlog_errno(ret);
2729                         goto out;
2730                 }
2731         }
2732
2733         if (clusters_to_add == 0)
2734                 goto out;
2735
2736         ret = ocfs2_reserve_clusters(osb, clusters_to_add, data_ac);
2737         if (ret < 0) {
2738                 if (ret != -ENOSPC)
2739                         mlog_errno(ret);
2740                 goto out;
2741         }
2742
2743 out:
2744         if (ret) {
2745                 if (*meta_ac) {
2746                         ocfs2_free_alloc_context(*meta_ac);
2747                         *meta_ac = NULL;
2748                 }
2749
2750                 /*
2751                  * We cannot have an error and a non null *data_ac.
2752                  */
2753         }
2754
2755         return ret;
2756 }
2757
2758 /*
2759  * Read the inode specified by blkno to get suballoc_slot and
2760  * suballoc_bit.
2761  */
2762 static int ocfs2_get_suballoc_slot_bit(struct ocfs2_super *osb, u64 blkno,
2763                                        u16 *suballoc_slot, u64 *group_blkno,
2764                                        u16 *suballoc_bit)
2765 {
2766         int status;
2767         struct buffer_head *inode_bh = NULL;
2768         struct ocfs2_dinode *inode_fe;
2769
2770         trace_ocfs2_get_suballoc_slot_bit((unsigned long long)blkno);
2771
2772         /* dirty read disk */
2773         status = ocfs2_read_blocks_sync(osb, blkno, 1, &inode_bh);
2774         if (status < 0) {
2775                 mlog(ML_ERROR, "read block %llu failed %d\n",
2776                      (unsigned long long)blkno, status);
2777                 goto bail;
2778         }
2779
2780         inode_fe = (struct ocfs2_dinode *) inode_bh->b_data;
2781         if (!OCFS2_IS_VALID_DINODE(inode_fe)) {
2782                 mlog(ML_ERROR, "invalid inode %llu requested\n",
2783                      (unsigned long long)blkno);
2784                 status = -EINVAL;
2785                 goto bail;
2786         }
2787
2788         if (le16_to_cpu(inode_fe->i_suballoc_slot) != (u16)OCFS2_INVALID_SLOT &&
2789             (u32)le16_to_cpu(inode_fe->i_suballoc_slot) > osb->max_slots - 1) {
2790                 mlog(ML_ERROR, "inode %llu has invalid suballoc slot %u\n",
2791                      (unsigned long long)blkno,
2792                      (u32)le16_to_cpu(inode_fe->i_suballoc_slot));
2793                 status = -EINVAL;
2794                 goto bail;
2795         }
2796
2797         if (suballoc_slot)
2798                 *suballoc_slot = le16_to_cpu(inode_fe->i_suballoc_slot);
2799         if (suballoc_bit)
2800                 *suballoc_bit = le16_to_cpu(inode_fe->i_suballoc_bit);
2801         if (group_blkno)
2802                 *group_blkno = le64_to_cpu(inode_fe->i_suballoc_loc);
2803
2804 bail:
2805         brelse(inode_bh);
2806
2807         if (status)
2808                 mlog_errno(status);
2809         return status;
2810 }
2811
2812 /*
2813  * test whether bit is SET in allocator bitmap or not.  on success, 0
2814  * is returned and *res is 1 for SET; 0 otherwise.  when fails, errno
2815  * is returned and *res is meaningless.  Call this after you have
2816  * cluster locked against suballoc, or you may get a result based on
2817  * non-up2date contents
2818  */
2819 static int ocfs2_test_suballoc_bit(struct ocfs2_super *osb,
2820                                    struct inode *suballoc,
2821                                    struct buffer_head *alloc_bh,
2822                                    u64 group_blkno, u64 blkno,
2823                                    u16 bit, int *res)
2824 {
2825         struct ocfs2_dinode *alloc_di;
2826         struct ocfs2_group_desc *group;
2827         struct buffer_head *group_bh = NULL;
2828         u64 bg_blkno;
2829         int status;
2830
2831         trace_ocfs2_test_suballoc_bit((unsigned long long)blkno,
2832                                       (unsigned int)bit);
2833
2834         alloc_di = (struct ocfs2_dinode *)alloc_bh->b_data;
2835         if ((bit + 1) > ocfs2_bits_per_group(&alloc_di->id2.i_chain)) {
2836                 mlog(ML_ERROR, "suballoc bit %u out of range of %u\n",
2837                      (unsigned int)bit,
2838                      ocfs2_bits_per_group(&alloc_di->id2.i_chain));
2839                 status = -EINVAL;
2840                 goto bail;
2841         }
2842
2843         bg_blkno = group_blkno ? group_blkno :
2844                    ocfs2_which_suballoc_group(blkno, bit);
2845         status = ocfs2_read_group_descriptor(suballoc, alloc_di, bg_blkno,
2846                                              &group_bh);
2847         if (status < 0) {
2848                 mlog(ML_ERROR, "read group %llu failed %d\n",
2849                      (unsigned long long)bg_blkno, status);
2850                 goto bail;
2851         }
2852
2853         group = (struct ocfs2_group_desc *) group_bh->b_data;
2854         *res = ocfs2_test_bit(bit, (unsigned long *)group->bg_bitmap);
2855
2856 bail:
2857         brelse(group_bh);
2858
2859         if (status)
2860                 mlog_errno(status);
2861         return status;
2862 }
2863
2864 /*
2865  * Test if the bit representing this inode (blkno) is set in the
2866  * suballocator.
2867  *
2868  * On success, 0 is returned and *res is 1 for SET; 0 otherwise.
2869  *
2870  * In the event of failure, a negative value is returned and *res is
2871  * meaningless.
2872  *
2873  * Callers must make sure to hold nfs_sync_lock to prevent
2874  * ocfs2_delete_inode() on another node from accessing the same
2875  * suballocator concurrently.
2876  */
2877 int ocfs2_test_inode_bit(struct ocfs2_super *osb, u64 blkno, int *res)
2878 {
2879         int status;
2880         u64 group_blkno = 0;
2881         u16 suballoc_bit = 0, suballoc_slot = 0;
2882         struct inode *inode_alloc_inode;
2883         struct buffer_head *alloc_bh = NULL;
2884
2885         trace_ocfs2_test_inode_bit((unsigned long long)blkno);
2886
2887         status = ocfs2_get_suballoc_slot_bit(osb, blkno, &suballoc_slot,
2888                                              &group_blkno, &suballoc_bit);
2889         if (status < 0) {
2890                 mlog(ML_ERROR, "get alloc slot and bit failed %d\n", status);
2891                 goto bail;
2892         }
2893
2894         if (suballoc_slot == (u16)OCFS2_INVALID_SLOT)
2895                 inode_alloc_inode = ocfs2_get_system_file_inode(osb,
2896                         GLOBAL_INODE_ALLOC_SYSTEM_INODE, suballoc_slot);
2897         else
2898                 inode_alloc_inode = ocfs2_get_system_file_inode(osb,
2899                         INODE_ALLOC_SYSTEM_INODE, suballoc_slot);
2900         if (!inode_alloc_inode) {
2901                 /* the error code could be inaccurate, but we are not able to
2902                  * get the correct one. */
2903                 status = -EINVAL;
2904                 mlog(ML_ERROR, "unable to get alloc inode in slot %u\n",
2905                      (u32)suballoc_slot);
2906                 goto bail;
2907         }
2908
2909         inode_lock(inode_alloc_inode);
2910         status = ocfs2_inode_lock(inode_alloc_inode, &alloc_bh, 0);
2911         if (status < 0) {
2912                 inode_unlock(inode_alloc_inode);
2913                 iput(inode_alloc_inode);
2914                 mlog(ML_ERROR, "lock on alloc inode on slot %u failed %d\n",
2915                      (u32)suballoc_slot, status);
2916                 goto bail;
2917         }
2918
2919         status = ocfs2_test_suballoc_bit(osb, inode_alloc_inode, alloc_bh,
2920                                          group_blkno, blkno, suballoc_bit, res);
2921         if (status < 0)
2922                 mlog(ML_ERROR, "test suballoc bit failed %d\n", status);
2923
2924         ocfs2_inode_unlock(inode_alloc_inode, 0);
2925         inode_unlock(inode_alloc_inode);
2926
2927         iput(inode_alloc_inode);
2928         brelse(alloc_bh);
2929 bail:
2930         if (status)
2931                 mlog_errno(status);
2932         return status;
2933 }