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 = slot;
 899         else if (type == EXTENT_ALLOC_SYSTEM_INODE)
 900                 osb->s_meta_steal_slot = 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
1153         return status;
1154 }
1155
1156 /* Callers don't need to care which bitmap (local alloc or main) to
1157  * use so we figure it out for them, but unfortunately this clutters
1158  * things a bit. */
1159 static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
1160                                              u32 bits_wanted, u64 max_block,
1161                                              int flags,
1162                                              struct ocfs2_alloc_context **ac)
1163 {
1164         int status, ret = 0;
1165         int retried = 0;
1166
1167         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1168         if (!(*ac)) {
1169                 status = -ENOMEM;
1170                 mlog_errno(status);
1171                 goto bail;
1172         }
1173
1174         (*ac)->ac_bits_wanted = bits_wanted;
1175         (*ac)->ac_max_block = max_block;
1176
1177         status = -ENOSPC;
1178         if (!(flags & ALLOC_GROUPS_FROM_GLOBAL) &&
1179             ocfs2_alloc_should_use_local(osb, bits_wanted)) {
1180                 status = ocfs2_reserve_local_alloc_bits(osb,
1181                                                         bits_wanted,
1182                                                         *ac);
1183                 if ((status < 0) && (status != -ENOSPC)) {
1184                         mlog_errno(status);
1185                         goto bail;
1186                 }
1187         }
1188
1189         if (status == -ENOSPC) {
1190 retry:
1191                 status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
1192                 /* Retry if there is sufficient space cached in truncate log */
1193                 if (status == -ENOSPC && !retried) {
1194                         retried = 1;
1195                         ocfs2_inode_unlock((*ac)->ac_inode, 1);
1196                         inode_unlock((*ac)->ac_inode);
1197
1198                         ret = ocfs2_try_to_free_truncate_log(osb, bits_wanted);
1199                         if (ret == 1) {
1200                                 iput((*ac)->ac_inode);
1201                                 (*ac)->ac_inode = NULL;
1202                                 goto retry;
1203                         }
1204
1205                         if (ret < 0)
1206                                 mlog_errno(ret);
1207
1208                         inode_lock((*ac)->ac_inode);
1209                         ret = ocfs2_inode_lock((*ac)->ac_inode, NULL, 1);
1210                         if (ret < 0) {
1211                                 mlog_errno(ret);
1212                                 inode_unlock((*ac)->ac_inode);
1213                                 iput((*ac)->ac_inode);
1214                                 (*ac)->ac_inode = NULL;
1215                                 goto bail;
1216                         }
1217                 }
1218                 if (status < 0) {
1219                         if (status != -ENOSPC)
1220                                 mlog_errno(status);
1221                         goto bail;
1222                 }
1223         }
1224
1225         status = 0;
1226 bail:
1227         if ((status < 0) && *ac) {
1228                 ocfs2_free_alloc_context(*ac);
1229                 *ac = NULL;
1230         }
1231
1232         if (status)
1233                 mlog_errno(status);
1234         return status;
1235 }
1236
1237 int ocfs2_reserve_clusters(struct ocfs2_super *osb,
1238                            u32 bits_wanted,
1239                            struct ocfs2_alloc_context **ac)
1240 {
1241         return ocfs2_reserve_clusters_with_limit(osb, bits_wanted, 0,
1242                                                  ALLOC_NEW_GROUP, ac);
1243 }
1244
1245 /*
1246  * More or less lifted from ext3. I'll leave their description below:
1247  *
1248  * "For ext3 allocations, we must not reuse any blocks which are
1249  * allocated in the bitmap buffer's "last committed data" copy.  This
1250  * prevents deletes from freeing up the page for reuse until we have
1251  * committed the delete transaction.
1252  *
1253  * If we didn't do this, then deleting something and reallocating it as
1254  * data would allow the old block to be overwritten before the
1255  * transaction committed (because we force data to disk before commit).
1256  * This would lead to corruption if we crashed between overwriting the
1257  * data and committing the delete.
1258  *
1259  * @@@ We may want to make this allocation behaviour conditional on
1260  * data-writes at some point, and disable it for metadata allocations or
1261  * sync-data inodes."
1262  *
1263  * Note: OCFS2 already does this differently for metadata vs data
1264  * allocations, as those bitmaps are separate and undo access is never
1265  * called on a metadata group descriptor.
1266  */
1267 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
1268                                          int nr)
1269 {
1270         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1271         int ret;
1272
1273         if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
1274                 return 0;
1275
1276         if (!buffer_jbd(bg_bh))
1277                 return 1;
1278
1279         jbd_lock_bh_state(bg_bh);
1280         bg = (struct ocfs2_group_desc *) bh2jh(bg_bh)->b_committed_data;
1281         if (bg)
1282                 ret = !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
1283         else
1284                 ret = 1;
1285         jbd_unlock_bh_state(bg_bh);
1286
1287         return ret;
1288 }
1289
1290 static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
1291                                              struct buffer_head *bg_bh,
1292                                              unsigned int bits_wanted,
1293                                              unsigned int total_bits,
1294                                              struct ocfs2_suballoc_result *res)
1295 {
1296         void *bitmap;
1297         u16 best_offset, best_size;
1298         int offset, start, found, status = 0;
1299         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1300
1301         /* Callers got this descriptor from
1302          * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1303         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1304
1305         found = start = best_offset = best_size = 0;
1306         bitmap = bg->bg_bitmap;
1307
1308         while((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) != -1) {
1309                 if (offset == total_bits)
1310                         break;
1311
1312                 if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
1313                         /* We found a zero, but we can't use it as it
1314                          * hasn't been put to disk yet! */
1315                         found = 0;
1316                         start = offset + 1;
1317                 } else if (offset == start) {
1318                         /* we found a zero */
1319                         found++;
1320                         /* move start to the next bit to test */
1321                         start++;
1322                 } else {
1323                         /* got a zero after some ones */
1324                         found = 1;
1325                         start = offset + 1;
1326                 }
1327                 if (found > best_size) {
1328                         best_size = found;
1329                         best_offset = start - found;
1330                 }
1331                 /* we got everything we needed */
1332                 if (found == bits_wanted) {
1333                         /* mlog(0, "Found it all!\n"); */
1334                         break;
1335                 }
1336         }
1337
1338         if (best_size) {
1339                 res->sr_bit_offset = best_offset;
1340                 res->sr_bits = best_size;
1341         } else {
1342                 status = -ENOSPC;
1343                 /* No error log here -- see the comment above
1344                  * ocfs2_test_bg_bit_allocatable */
1345         }
1346
1347         return status;
1348 }
1349
1350 int ocfs2_block_group_set_bits(handle_t *handle,
1351                                              struct inode *alloc_inode,
1352                                              struct ocfs2_group_desc *bg,
1353                                              struct buffer_head *group_bh,
1354                                              unsigned int bit_off,
1355                                              unsigned int num_bits)
1356 {
1357         int status;
1358         void *bitmap = bg->bg_bitmap;
1359         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1360
1361         /* All callers get the descriptor via
1362          * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1363         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1364         BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
1365
1366         trace_ocfs2_block_group_set_bits(bit_off, num_bits);
1367
1368         if (ocfs2_is_cluster_bitmap(alloc_inode))
1369                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1370
1371         status = ocfs2_journal_access_gd(handle,
1372                                          INODE_CACHE(alloc_inode),
1373                                          group_bh,
1374                                          journal_type);
1375         if (status < 0) {
1376                 mlog_errno(status);
1377                 goto bail;
1378         }
1379
1380         le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
1381         if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
1382                 return ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit count %u but claims %u are freed. num_bits %d\n",
1383                                    (unsigned long long)le64_to_cpu(bg->bg_blkno),
1384                                    le16_to_cpu(bg->bg_bits),
1385                                    le16_to_cpu(bg->bg_free_bits_count),
1386                                    num_bits);
1387         }
1388         while(num_bits--)
1389                 ocfs2_set_bit(bit_off++, bitmap);
1390
1391         ocfs2_journal_dirty(handle, group_bh);
1392
1393 bail:
1394         return status;
1395 }
1396
1397 /* find the one with the most empty bits */
1398 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
1399 {
1400         u16 curr, best;
1401
1402         BUG_ON(!cl->cl_next_free_rec);
1403
1404         best = curr = 0;
1405         while (curr < le16_to_cpu(cl->cl_next_free_rec)) {
1406                 if (le32_to_cpu(cl->cl_recs[curr].c_free) >
1407                     le32_to_cpu(cl->cl_recs[best].c_free))
1408                         best = curr;
1409                 curr++;
1410         }
1411
1412         BUG_ON(best >= le16_to_cpu(cl->cl_next_free_rec));
1413         return best;
1414 }
1415
1416 static int ocfs2_relink_block_group(handle_t *handle,
1417                                     struct inode *alloc_inode,
1418                                     struct buffer_head *fe_bh,
1419                                     struct buffer_head *bg_bh,
1420                                     struct buffer_head *prev_bg_bh,
1421                                     u16 chain)
1422 {
1423         int status;
1424         /* there is a really tiny chance the journal calls could fail,
1425          * but we wouldn't want inconsistent blocks in *any* case. */
1426         u64 bg_ptr, prev_bg_ptr;
1427         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
1428         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
1429         struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
1430
1431         /* The caller got these descriptors from
1432          * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
1433         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
1434         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(prev_bg));
1435
1436         trace_ocfs2_relink_block_group(
1437                 (unsigned long long)le64_to_cpu(fe->i_blkno), chain,
1438                 (unsigned long long)le64_to_cpu(bg->bg_blkno),
1439                 (unsigned long long)le64_to_cpu(prev_bg->bg_blkno));
1440
1441         bg_ptr = le64_to_cpu(bg->bg_next_group);
1442         prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
1443
1444         status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1445                                          prev_bg_bh,
1446                                          OCFS2_JOURNAL_ACCESS_WRITE);
1447         if (status < 0)
1448                 goto out;
1449
1450         prev_bg->bg_next_group = bg->bg_next_group;
1451         ocfs2_journal_dirty(handle, prev_bg_bh);
1452
1453         status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
1454                                          bg_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1455         if (status < 0)
1456                 goto out_rollback_prev_bg;
1457
1458         bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
1459         ocfs2_journal_dirty(handle, bg_bh);
1460
1461         status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
1462                                          fe_bh, OCFS2_JOURNAL_ACCESS_WRITE);
1463         if (status < 0)
1464                 goto out_rollback_bg;
1465
1466         fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
1467         ocfs2_journal_dirty(handle, fe_bh);
1468
1469 out:
1470         if (status < 0)
1471                 mlog_errno(status);
1472         return status;
1473
1474 out_rollback_bg:
1475         bg->bg_next_group = cpu_to_le64(bg_ptr);
1476 out_rollback_prev_bg:
1477         prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
1478         goto out;
1479 }
1480
1481 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
1482                                                      u32 wanted)
1483 {
1484         return le16_to_cpu(bg->bg_free_bits_count) > wanted;
1485 }
1486
1487 /* return 0 on success, -ENOSPC to keep searching and any other < 0
1488  * value on error. */
1489 static int ocfs2_cluster_group_search(struct inode *inode,
1490                                       struct buffer_head *group_bh,
1491                                       u32 bits_wanted, u32 min_bits,
1492                                       u64 max_block,
1493                                       struct ocfs2_suballoc_result *res)
1494 {
1495         int search = -ENOSPC;
1496         int ret;
1497         u64 blkoff;
1498         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
1499         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1500         unsigned int max_bits, gd_cluster_off;
1501
1502         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1503
1504         if (gd->bg_free_bits_count) {
1505                 max_bits = le16_to_cpu(gd->bg_bits);
1506
1507                 /* Tail groups in cluster bitmaps which aren't cpg
1508                  * aligned are prone to partial extension by a failed
1509                  * fs resize. If the file system resize never got to
1510                  * update the dinode cluster count, then we don't want
1511                  * to trust any clusters past it, regardless of what
1512                  * the group descriptor says. */
1513                 gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
1514                                                           le64_to_cpu(gd->bg_blkno));
1515                 if ((gd_cluster_off + max_bits) >
1516                     OCFS2_I(inode)->ip_clusters) {
1517                         max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
1518                         trace_ocfs2_cluster_group_search_wrong_max_bits(
1519                                 (unsigned long long)le64_to_cpu(gd->bg_blkno),
1520                                 le16_to_cpu(gd->bg_bits),
1521                                 OCFS2_I(inode)->ip_clusters, max_bits);
1522                 }
1523
1524                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1525                                                         group_bh, bits_wanted,
1526                                                         max_bits, res);
1527                 if (ret)
1528                         return ret;
1529
1530                 if (max_block) {
1531                         blkoff = ocfs2_clusters_to_blocks(inode->i_sb,
1532                                                           gd_cluster_off +
1533                                                           res->sr_bit_offset +
1534                                                           res->sr_bits);
1535                         trace_ocfs2_cluster_group_search_max_block(
1536                                 (unsigned long long)blkoff,
1537                                 (unsigned long long)max_block);
1538                         if (blkoff > max_block)
1539                                 return -ENOSPC;
1540                 }
1541
1542                 /* ocfs2_block_group_find_clear_bits() might
1543                  * return success, but we still want to return
1544                  * -ENOSPC unless it found the minimum number
1545                  * of bits. */
1546                 if (min_bits <= res->sr_bits)
1547                         search = 0; /* success */
1548                 else if (res->sr_bits) {
1549                         /*
1550                          * Don't show bits which we'll be returning
1551                          * for allocation to the local alloc bitmap.
1552                          */
1553                         ocfs2_local_alloc_seen_free_bits(osb, res->sr_bits);
1554                 }
1555         }
1556
1557         return search;
1558 }
1559
1560 static int ocfs2_block_group_search(struct inode *inode,
1561                                     struct buffer_head *group_bh,
1562                                     u32 bits_wanted, u32 min_bits,
1563                                     u64 max_block,
1564                                     struct ocfs2_suballoc_result *res)
1565 {
1566         int ret = -ENOSPC;
1567         u64 blkoff;
1568         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
1569
1570         BUG_ON(min_bits != 1);
1571         BUG_ON(ocfs2_is_cluster_bitmap(inode));
1572
1573         if (bg->bg_free_bits_count) {
1574                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1575                                                         group_bh, bits_wanted,
1576                                                         le16_to_cpu(bg->bg_bits),
1577                                                         res);
1578                 if (!ret && max_block) {
1579                         blkoff = le64_to_cpu(bg->bg_blkno) +
1580                                 res->sr_bit_offset + res->sr_bits;
1581                         trace_ocfs2_block_group_search_max_block(
1582                                 (unsigned long long)blkoff,
1583                                 (unsigned long long)max_block);
1584                         if (blkoff > max_block)
1585                                 ret = -ENOSPC;
1586                 }
1587         }
1588
1589         return ret;
1590 }
1591
1592 int ocfs2_alloc_dinode_update_counts(struct inode *inode,
1593                                        handle_t *handle,
1594                                        struct buffer_head *di_bh,
1595                                        u32 num_bits,
1596                                        u16 chain)
1597 {
1598         int ret;
1599         u32 tmp_used;
1600         struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1601         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &di->id2.i_chain;
1602
1603         ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
1604                                       OCFS2_JOURNAL_ACCESS_WRITE);
1605         if (ret < 0) {
1606                 mlog_errno(ret);
1607                 goto out;
1608         }
1609
1610         tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1611         di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
1612         le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
1613         ocfs2_journal_dirty(handle, di_bh);
1614
1615 out:
1616         return ret;
1617 }
1618
1619 void ocfs2_rollback_alloc_dinode_counts(struct inode *inode,
1620                                        struct buffer_head *di_bh,
1621                                        u32 num_bits,
1622                                        u16 chain)
1623 {
1624         u32 tmp_used;
1625         struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1626         struct ocfs2_chain_list *cl;
1627
1628         cl = (struct ocfs2_chain_list *)&di->id2.i_chain;
1629         tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1630         di->id1.bitmap1.i_used = cpu_to_le32(tmp_used - num_bits);
1631         le32_add_cpu(&cl->cl_recs[chain].c_free, num_bits);
1632 }
1633
1634 static int ocfs2_bg_discontig_fix_by_rec(struct ocfs2_suballoc_result *res,
1635                                          struct ocfs2_extent_rec *rec,
1636                                          struct ocfs2_chain_list *cl)
1637 {
1638         unsigned int bpc = le16_to_cpu(cl->cl_bpc);
1639         unsigned int bitoff = le32_to_cpu(rec->e_cpos) * bpc;
1640         unsigned int bitcount = le16_to_cpu(rec->e_leaf_clusters) * bpc;
1641
1642         if (res->sr_bit_offset < bitoff)
1643                 return 0;
1644         if (res->sr_bit_offset >= (bitoff + bitcount))
1645                 return 0;
1646         res->sr_blkno = le64_to_cpu(rec->e_blkno) +
1647                 (res->sr_bit_offset - bitoff);
1648         if ((res->sr_bit_offset + res->sr_bits) > (bitoff + bitcount))
1649                 res->sr_bits = (bitoff + bitcount) - res->sr_bit_offset;
1650         return 1;
1651 }
1652
1653 static void ocfs2_bg_discontig_fix_result(struct ocfs2_alloc_context *ac,
1654                                           struct ocfs2_group_desc *bg,
1655                                           struct ocfs2_suballoc_result *res)
1656 {
1657         int i;
1658         u64 bg_blkno = res->sr_bg_blkno;  /* Save off */
1659         struct ocfs2_extent_rec *rec;
1660         struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1661         struct ocfs2_chain_list *cl = &di->id2.i_chain;
1662
1663         if (ocfs2_is_cluster_bitmap(ac->ac_inode)) {
1664                 res->sr_blkno = 0;
1665                 return;
1666         }
1667
1668         res->sr_blkno = res->sr_bg_blkno + res->sr_bit_offset;
1669         res->sr_bg_blkno = 0;  /* Clear it for contig block groups */
1670         if (!ocfs2_supports_discontig_bg(OCFS2_SB(ac->ac_inode->i_sb)) ||
1671             !bg->bg_list.l_next_free_rec)
1672                 return;
1673
1674         for (i = 0; i < le16_to_cpu(bg->bg_list.l_next_free_rec); i++) {
1675                 rec = &bg->bg_list.l_recs[i];
1676                 if (ocfs2_bg_discontig_fix_by_rec(res, rec, cl)) {
1677                         res->sr_bg_blkno = bg_blkno;  /* Restore */
1678                         break;
1679                 }
1680         }
1681 }
1682
1683 static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
1684                                   handle_t *handle,
1685                                   u32 bits_wanted,
1686                                   u32 min_bits,
1687                                   struct ocfs2_suballoc_result *res,
1688                                   u16 *bits_left)
1689 {
1690         int ret;
1691         struct buffer_head *group_bh = NULL;
1692         struct ocfs2_group_desc *gd;
1693         struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
1694         struct inode *alloc_inode = ac->ac_inode;
1695
1696         ret = ocfs2_read_group_descriptor(alloc_inode, di,
1697                                           res->sr_bg_blkno, &group_bh);
1698         if (ret < 0) {
1699                 mlog_errno(ret);
1700                 return ret;
1701         }
1702
1703         gd = (struct ocfs2_group_desc *) group_bh->b_data;
1704         ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
1705                                   ac->ac_max_block, res);
1706         if (ret < 0) {
1707                 if (ret != -ENOSPC)
1708                         mlog_errno(ret);
1709                 goto out;
1710         }
1711
1712         if (!ret)
1713                 ocfs2_bg_discontig_fix_result(ac, gd, res);
1714
1715         /*
1716          * sr_bg_blkno might have been changed by
1717          * ocfs2_bg_discontig_fix_result
1718          */
1719         res->sr_bg_stable_blkno = group_bh->b_blocknr;
1720
1721         if (ac->ac_find_loc_only)
1722                 goto out_loc_only;
1723
1724         ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
1725                                                res->sr_bits,
1726                                                le16_to_cpu(gd->bg_chain));
1727         if (ret < 0) {
1728                 mlog_errno(ret);
1729                 goto out;
1730         }
1731
1732         ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
1733                                          res->sr_bit_offset, res->sr_bits);
1734         if (ret < 0) {
1735                 ocfs2_rollback_alloc_dinode_counts(alloc_inode, ac->ac_bh,
1736                                                res->sr_bits,
1737                                                le16_to_cpu(gd->bg_chain));
1738                 mlog_errno(ret);
1739         }
1740
1741 out_loc_only:
1742         *bits_left = le16_to_cpu(gd->bg_free_bits_count);
1743
1744 out:
1745         brelse(group_bh);
1746
1747         return ret;
1748 }
1749
1750 static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
1751                               handle_t *handle,
1752                               u32 bits_wanted,
1753                               u32 min_bits,
1754                               struct ocfs2_suballoc_result *res,
1755                               u16 *bits_left)
1756 {
1757         int status;
1758         u16 chain;
1759         u64 next_group;
1760         struct inode *alloc_inode = ac->ac_inode;
1761         struct buffer_head *group_bh = NULL;
1762         struct buffer_head *prev_group_bh = NULL;
1763         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1764         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1765         struct ocfs2_group_desc *bg;
1766
1767         chain = ac->ac_chain;
1768         trace_ocfs2_search_chain_begin(
1769                 (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
1770                 bits_wanted, chain);
1771
1772         status = ocfs2_read_group_descriptor(alloc_inode, fe,
1773                                              le64_to_cpu(cl->cl_recs[chain].c_blkno),
1774                                              &group_bh);
1775         if (status < 0) {
1776                 mlog_errno(status);
1777                 goto bail;
1778         }
1779         bg = (struct ocfs2_group_desc *) group_bh->b_data;
1780
1781         status = -ENOSPC;
1782         /* for now, the chain search is a bit simplistic. We just use
1783          * the 1st group with any empty bits. */
1784         while ((status = ac->ac_group_search(alloc_inode, group_bh,
1785                                              bits_wanted, min_bits,
1786                                              ac->ac_max_block,
1787                                              res)) == -ENOSPC) {
1788                 if (!bg->bg_next_group)
1789                         break;
1790
1791                 brelse(prev_group_bh);
1792                 prev_group_bh = NULL;
1793
1794                 next_group = le64_to_cpu(bg->bg_next_group);
1795                 prev_group_bh = group_bh;
1796                 group_bh = NULL;
1797                 status = ocfs2_read_group_descriptor(alloc_inode, fe,
1798                                                      next_group, &group_bh);
1799                 if (status < 0) {
1800                         mlog_errno(status);
1801                         goto bail;
1802                 }
1803                 bg = (struct ocfs2_group_desc *) group_bh->b_data;
1804         }
1805         if (status < 0) {
1806                 if (status != -ENOSPC)
1807                         mlog_errno(status);
1808                 goto bail;
1809         }
1810
1811         trace_ocfs2_search_chain_succ(
1812                 (unsigned long long)le64_to_cpu(bg->bg_blkno), res->sr_bits);
1813
1814         res->sr_bg_blkno = le64_to_cpu(bg->bg_blkno);
1815
1816         BUG_ON(res->sr_bits == 0);
1817         if (!status)
1818                 ocfs2_bg_discontig_fix_result(ac, bg, res);
1819
1820         /*
1821          * sr_bg_blkno might have been changed by
1822          * ocfs2_bg_discontig_fix_result
1823          */
1824         res->sr_bg_stable_blkno = group_bh->b_blocknr;
1825
1826         /*
1827          * Keep track of previous block descriptor read. When
1828          * we find a target, if we have read more than X
1829          * number of descriptors, and the target is reasonably
1830          * empty, relink him to top of his chain.
1831          *
1832          * We've read 0 extra blocks and only send one more to
1833          * the transaction, yet the next guy to search has a
1834          * much easier time.
1835          *
1836          * Do this *after* figuring out how many bits we're taking out
1837          * of our target group.
1838          */
1839         if (!ac->ac_disable_chain_relink &&
1840             (prev_group_bh) &&
1841             (ocfs2_block_group_reasonably_empty(bg, res->sr_bits))) {
1842                 status = ocfs2_relink_block_group(handle, alloc_inode,
1843                                                   ac->ac_bh, group_bh,
1844                                                   prev_group_bh, chain);
1845                 if (status < 0) {
1846                         mlog_errno(status);
1847                         goto bail;
1848                 }
1849         }
1850
1851         if (ac->ac_find_loc_only)
1852                 goto out_loc_only;
1853
1854         status = ocfs2_alloc_dinode_update_counts(alloc_inode, handle,
1855                                                   ac->ac_bh, res->sr_bits,
1856                                                   chain);
1857         if (status) {
1858                 mlog_errno(status);
1859                 goto bail;
1860         }
1861
1862         status = ocfs2_block_group_set_bits(handle,
1863                                             alloc_inode,
1864                                             bg,
1865                                             group_bh,
1866                                             res->sr_bit_offset,
1867                                             res->sr_bits);
1868         if (status < 0) {
1869                 ocfs2_rollback_alloc_dinode_counts(alloc_inode,
1870                                         ac->ac_bh, res->sr_bits, chain);
1871                 mlog_errno(status);
1872                 goto bail;
1873         }
1874
1875         trace_ocfs2_search_chain_end(
1876                         (unsigned long long)le64_to_cpu(fe->i_blkno),
1877                         res->sr_bits);
1878
1879 out_loc_only:
1880         *bits_left = le16_to_cpu(bg->bg_free_bits_count);
1881 bail:
1882         brelse(group_bh);
1883         brelse(prev_group_bh);
1884
1885         if (status)
1886                 mlog_errno(status);
1887         return status;
1888 }
1889
1890 /* will give out up to bits_wanted contiguous bits. */
1891 static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
1892                                      handle_t *handle,
1893                                      u32 bits_wanted,
1894                                      u32 min_bits,
1895                                      struct ocfs2_suballoc_result *res)
1896 {
1897         int status;
1898         u16 victim, i;
1899         u16 bits_left = 0;
1900         u64 hint = ac->ac_last_group;
1901         struct ocfs2_chain_list *cl;
1902         struct ocfs2_dinode *fe;
1903
1904         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1905         BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1906         BUG_ON(!ac->ac_bh);
1907
1908         fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1909
1910         /* The bh was validated by the inode read during
1911          * ocfs2_reserve_suballoc_bits().  Any corruption is a code bug. */
1912         BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
1913
1914         if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1915             le32_to_cpu(fe->id1.bitmap1.i_total)) {
1916                 status = ocfs2_error(ac->ac_inode->i_sb,
1917                                      "Chain allocator dinode %llu has %u used bits but only %u total\n",
1918                                      (unsigned long long)le64_to_cpu(fe->i_blkno),
1919                                      le32_to_cpu(fe->id1.bitmap1.i_used),
1920                                      le32_to_cpu(fe->id1.bitmap1.i_total));
1921                 goto bail;
1922         }
1923
1924         res->sr_bg_blkno = hint;
1925         if (res->sr_bg_blkno) {
1926                 /* Attempt to short-circuit the usual search mechanism
1927                  * by jumping straight to the most recently used
1928                  * allocation group. This helps us maintain some
1929                  * contiguousness across allocations. */
1930                 status = ocfs2_search_one_group(ac, handle, bits_wanted,
1931                                                 min_bits, res, &bits_left);
1932                 if (!status)
1933                         goto set_hint;
1934                 if (status < 0 && status != -ENOSPC) {
1935                         mlog_errno(status);
1936                         goto bail;
1937                 }
1938         }
1939
1940         cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1941
1942         victim = ocfs2_find_victim_chain(cl);
1943         ac->ac_chain = victim;
1944
1945         status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1946                                     res, &bits_left);
1947         if (!status) {
1948                 if (ocfs2_is_cluster_bitmap(ac->ac_inode))
1949                         hint = res->sr_bg_blkno;
1950                 else
1951                         hint = ocfs2_group_from_res(res);
1952                 goto set_hint;
1953         }
1954         if (status < 0 && status != -ENOSPC) {
1955                 mlog_errno(status);
1956                 goto bail;
1957         }
1958
1959         trace_ocfs2_claim_suballoc_bits(victim);
1960
1961         /* If we didn't pick a good victim, then just default to
1962          * searching each chain in order. Don't allow chain relinking
1963          * because we only calculate enough journal credits for one
1964          * relink per alloc. */
1965         ac->ac_disable_chain_relink = 1;
1966         for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
1967                 if (i == victim)
1968                         continue;
1969                 if (!cl->cl_recs[i].c_free)
1970                         continue;
1971
1972                 ac->ac_chain = i;
1973                 status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1974                                             res, &bits_left);
1975                 if (!status) {
1976                         hint = ocfs2_group_from_res(res);
1977                         break;
1978                 }
1979                 if (status < 0 && status != -ENOSPC) {
1980                         mlog_errno(status);
1981                         goto bail;
1982                 }
1983         }
1984
1985 set_hint:
1986         if (status != -ENOSPC) {
1987                 /* If the next search of this group is not likely to
1988                  * yield a suitable extent, then we reset the last
1989                  * group hint so as to not waste a disk read */
1990                 if (bits_left < min_bits)
1991                         ac->ac_last_group = 0;
1992                 else
1993                         ac->ac_last_group = hint;
1994         }
1995
1996 bail:
1997         if (status)
1998                 mlog_errno(status);
1999         return status;
2000 }
2001
2002 int ocfs2_claim_metadata(handle_t *handle,
2003                          struct ocfs2_alloc_context *ac,
2004                          u32 bits_wanted,
2005                          u64 *suballoc_loc,
2006                          u16 *suballoc_bit_start,
2007                          unsigned int *num_bits,
2008                          u64 *blkno_start)
2009 {
2010         int status;
2011         struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
2012
2013         BUG_ON(!ac);
2014         BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
2015         BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
2016
2017         status = ocfs2_claim_suballoc_bits(ac,
2018                                            handle,
2019                                            bits_wanted,
2020                                            1,
2021                                            &res);
2022         if (status < 0) {
2023                 mlog_errno(status);
2024                 goto bail;
2025         }
2026         atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2027
2028         *suballoc_loc = res.sr_bg_blkno;
2029         *suballoc_bit_start = res.sr_bit_offset;
2030         *blkno_start = res.sr_blkno;
2031         ac->ac_bits_given += res.sr_bits;
2032         *num_bits = res.sr_bits;
2033         status = 0;
2034 bail:
2035         if (status)
2036                 mlog_errno(status);
2037         return status;
2038 }
2039
2040 static void ocfs2_init_inode_ac_group(struct inode *dir,
2041                                       struct buffer_head *parent_di_bh,
2042                                       struct ocfs2_alloc_context *ac)
2043 {
2044         struct ocfs2_dinode *di = (struct ocfs2_dinode *)parent_di_bh->b_data;
2045         /*
2046          * Try to allocate inodes from some specific group.
2047          *
2048          * If the parent dir has recorded the last group used in allocation,
2049          * cool, use it. Otherwise if we try to allocate new inode from the
2050          * same slot the parent dir belongs to, use the same chunk.
2051          *
2052          * We are very careful here to avoid the mistake of setting
2053          * ac_last_group to a group descriptor from a different (unlocked) slot.
2054          */
2055         if (OCFS2_I(dir)->ip_last_used_group &&
2056             OCFS2_I(dir)->ip_last_used_slot == ac->ac_alloc_slot)
2057                 ac->ac_last_group = OCFS2_I(dir)->ip_last_used_group;
2058         else if (le16_to_cpu(di->i_suballoc_slot) == ac->ac_alloc_slot) {
2059                 if (di->i_suballoc_loc)
2060                         ac->ac_last_group = le64_to_cpu(di->i_suballoc_loc);
2061                 else
2062                         ac->ac_last_group = ocfs2_which_suballoc_group(
2063                                         le64_to_cpu(di->i_blkno),
2064                                         le16_to_cpu(di->i_suballoc_bit));
2065         }
2066 }
2067
2068 static inline void ocfs2_save_inode_ac_group(struct inode *dir,
2069                                              struct ocfs2_alloc_context *ac)
2070 {
2071         OCFS2_I(dir)->ip_last_used_group = ac->ac_last_group;
2072         OCFS2_I(dir)->ip_last_used_slot = ac->ac_alloc_slot;
2073 }
2074
2075 int ocfs2_find_new_inode_loc(struct inode *dir,
2076                              struct buffer_head *parent_fe_bh,
2077                              struct ocfs2_alloc_context *ac,
2078                              u64 *fe_blkno)
2079 {
2080         int ret;
2081         handle_t *handle = NULL;
2082         struct ocfs2_suballoc_result *res;
2083
2084         BUG_ON(!ac);
2085         BUG_ON(ac->ac_bits_given != 0);
2086         BUG_ON(ac->ac_bits_wanted != 1);
2087         BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2088
2089         res = kzalloc(sizeof(*res), GFP_NOFS);
2090         if (res == NULL) {
2091                 ret = -ENOMEM;
2092                 mlog_errno(ret);
2093                 goto out;
2094         }
2095
2096         ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2097
2098         /*
2099          * The handle started here is for chain relink. Alternatively,
2100          * we could just disable relink for these calls.
2101          */
2102         handle = ocfs2_start_trans(OCFS2_SB(dir->i_sb), OCFS2_SUBALLOC_ALLOC);
2103         if (IS_ERR(handle)) {
2104                 ret = PTR_ERR(handle);
2105                 handle = NULL;
2106                 mlog_errno(ret);
2107                 goto out;
2108         }
2109
2110         /*
2111          * This will instruct ocfs2_claim_suballoc_bits and
2112          * ocfs2_search_one_group to search but save actual allocation
2113          * for later.
2114          */
2115         ac->ac_find_loc_only = 1;
2116
2117         ret = ocfs2_claim_suballoc_bits(ac, handle, 1, 1, res);
2118         if (ret < 0) {
2119                 mlog_errno(ret);
2120                 goto out;
2121         }
2122
2123         ac->ac_find_loc_priv = res;
2124         *fe_blkno = res->sr_blkno;
2125         ocfs2_update_inode_fsync_trans(handle, dir, 0);
2126 out:
2127         if (handle)
2128                 ocfs2_commit_trans(OCFS2_SB(dir->i_sb), handle);
2129
2130         if (ret)
2131                 kfree(res);
2132
2133         return ret;
2134 }
2135
2136 int ocfs2_claim_new_inode_at_loc(handle_t *handle,
2137                                  struct inode *dir,
2138                                  struct ocfs2_alloc_context *ac,
2139                                  u64 *suballoc_loc,
2140                                  u16 *suballoc_bit,
2141                                  u64 di_blkno)
2142 {
2143         int ret;
2144         u16 chain;
2145         struct ocfs2_suballoc_result *res = ac->ac_find_loc_priv;
2146         struct buffer_head *bg_bh = NULL;
2147         struct ocfs2_group_desc *bg;
2148         struct ocfs2_dinode *di = (struct ocfs2_dinode *) ac->ac_bh->b_data;
2149
2150         /*
2151          * Since di_blkno is being passed back in, we check for any
2152          * inconsistencies which may have happened between
2153          * calls. These are code bugs as di_blkno is not expected to
2154          * change once returned from ocfs2_find_new_inode_loc()
2155          */
2156         BUG_ON(res->sr_blkno != di_blkno);
2157
2158         ret = ocfs2_read_group_descriptor(ac->ac_inode, di,
2159                                           res->sr_bg_stable_blkno, &bg_bh);
2160         if (ret) {
2161                 mlog_errno(ret);
2162                 goto out;
2163         }
2164
2165         bg = (struct ocfs2_group_desc *) bg_bh->b_data;
2166         chain = le16_to_cpu(bg->bg_chain);
2167
2168         ret = ocfs2_alloc_dinode_update_counts(ac->ac_inode, handle,
2169                                                ac->ac_bh, res->sr_bits,
2170                                                chain);
2171         if (ret) {
2172                 mlog_errno(ret);
2173                 goto out;
2174         }
2175
2176         ret = ocfs2_block_group_set_bits(handle,
2177                                          ac->ac_inode,
2178                                          bg,
2179                                          bg_bh,
2180                                          res->sr_bit_offset,
2181                                          res->sr_bits);
2182         if (ret < 0) {
2183                 ocfs2_rollback_alloc_dinode_counts(ac->ac_inode,
2184                                                ac->ac_bh, res->sr_bits, chain);
2185                 mlog_errno(ret);
2186                 goto out;
2187         }
2188
2189         trace_ocfs2_claim_new_inode_at_loc((unsigned long long)di_blkno,
2190                                            res->sr_bits);
2191
2192         atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2193
2194         BUG_ON(res->sr_bits != 1);
2195
2196         *suballoc_loc = res->sr_bg_blkno;
2197         *suballoc_bit = res->sr_bit_offset;
2198         ac->ac_bits_given++;
2199         ocfs2_save_inode_ac_group(dir, ac);
2200
2201 out:
2202         brelse(bg_bh);
2203
2204         return ret;
2205 }
2206
2207 int ocfs2_claim_new_inode(handle_t *handle,
2208                           struct inode *dir,
2209                           struct buffer_head *parent_fe_bh,
2210                           struct ocfs2_alloc_context *ac,
2211                           u64 *suballoc_loc,
2212                           u16 *suballoc_bit,
2213                           u64 *fe_blkno)
2214 {
2215         int status;
2216         struct ocfs2_suballoc_result res;
2217
2218         BUG_ON(!ac);
2219         BUG_ON(ac->ac_bits_given != 0);
2220         BUG_ON(ac->ac_bits_wanted != 1);
2221         BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
2222
2223         ocfs2_init_inode_ac_group(dir, parent_fe_bh, ac);
2224
2225         status = ocfs2_claim_suballoc_bits(ac,
2226                                            handle,
2227                                            1,
2228                                            1,
2229                                            &res);
2230         if (status < 0) {
2231                 mlog_errno(status);
2232                 goto bail;
2233         }
2234         atomic_inc(&OCFS2_SB(ac->ac_inode->i_sb)->alloc_stats.bg_allocs);
2235
2236         BUG_ON(res.sr_bits != 1);
2237
2238         *suballoc_loc = res.sr_bg_blkno;
2239         *suballoc_bit = res.sr_bit_offset;
2240         *fe_blkno = res.sr_blkno;
2241         ac->ac_bits_given++;
2242         ocfs2_save_inode_ac_group(dir, ac);
2243         status = 0;
2244 bail:
2245         if (status)
2246                 mlog_errno(status);
2247         return status;
2248 }
2249
2250 /* translate a group desc. blkno and it's bitmap offset into
2251  * disk cluster offset. */
2252 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
2253                                                    u64 bg_blkno,
2254                                                    u16 bg_bit_off)
2255 {
2256         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2257         u32 cluster = 0;
2258
2259         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2260
2261         if (bg_blkno != osb->first_cluster_group_blkno)
2262                 cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
2263         cluster += (u32) bg_bit_off;
2264         return cluster;
2265 }
2266
2267 /* given a cluster offset, calculate which block group it belongs to
2268  * and return that block offset. */
2269 u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster)
2270 {
2271         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2272         u32 group_no;
2273
2274         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2275
2276         group_no = cluster / osb->bitmap_cpg;
2277         if (!group_no)
2278                 return osb->first_cluster_group_blkno;
2279         return ocfs2_clusters_to_blocks(inode->i_sb,
2280                                         group_no * osb->bitmap_cpg);
2281 }
2282
2283 /* given the block number of a cluster start, calculate which cluster
2284  * group and descriptor bitmap offset that corresponds to. */
2285 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
2286                                                 u64 data_blkno,
2287                                                 u64 *bg_blkno,
2288                                                 u16 *bg_bit_off)
2289 {
2290         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2291         u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
2292
2293         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
2294
2295         *bg_blkno = ocfs2_which_cluster_group(inode,
2296                                               data_cluster);
2297
2298         if (*bg_blkno == osb->first_cluster_group_blkno)
2299                 *bg_bit_off = (u16) data_cluster;
2300         else
2301                 *bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
2302                                                              data_blkno - *bg_blkno);
2303 }
2304
2305 /*
2306  * min_bits - minimum contiguous chunk from this total allocation we
2307  * can handle. set to what we asked for originally for a full
2308  * contig. allocation, set to '1' to indicate we can deal with extents
2309  * of any size.
2310  */
2311 int __ocfs2_claim_clusters(handle_t *handle,
2312                            struct ocfs2_alloc_context *ac,
2313                            u32 min_clusters,
2314                            u32 max_clusters,
2315                            u32 *cluster_start,
2316                            u32 *num_clusters)
2317 {
2318         int status;
2319         unsigned int bits_wanted = max_clusters;
2320         struct ocfs2_suballoc_result res = { .sr_blkno = 0, };
2321         struct ocfs2_super *osb = OCFS2_SB(ac->ac_inode->i_sb);
2322
2323         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
2324
2325         BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
2326                && ac->ac_which != OCFS2_AC_USE_MAIN);
2327
2328         if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
2329                 WARN_ON(min_clusters > 1);
2330
2331                 status = ocfs2_claim_local_alloc_bits(osb,
2332                                                       handle,
2333                                                       ac,
2334                                                       bits_wanted,
2335                                                       cluster_start,
2336                                                       num_clusters);
2337                 if (!status)
2338                         atomic_inc(&osb->alloc_stats.local_data);
2339         } else {
2340                 if (min_clusters > (osb->bitmap_cpg - 1)) {
2341                         /* The only paths asking for contiguousness
2342                          * should know about this already. */
2343                         mlog(ML_ERROR, "minimum allocation requested %u exceeds "
2344                              "group bitmap size %u!\n", min_clusters,
2345                              osb->bitmap_cpg);
2346                         status = -ENOSPC;
2347                         goto bail;
2348                 }
2349                 /* clamp the current request down to a realistic size. */
2350                 if (bits_wanted > (osb->bitmap_cpg - 1))
2351                         bits_wanted = osb->bitmap_cpg - 1;
2352
2353                 status = ocfs2_claim_suballoc_bits(ac,
2354                                                    handle,
2355                                                    bits_wanted,
2356                                                    min_clusters,
2357                                                    &res);
2358                 if (!status) {
2359                         BUG_ON(res.sr_blkno); /* cluster alloc can't set */
2360                         *cluster_start =
2361                                 ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
2362                                                                  res.sr_bg_blkno,
2363                                                                  res.sr_bit_offset);
2364                         atomic_inc(&osb->alloc_stats.bitmap_data);
2365                         *num_clusters = res.sr_bits;
2366                 }
2367         }
2368         if (status < 0) {
2369                 if (status != -ENOSPC)
2370                         mlog_errno(status);
2371                 goto bail;
2372         }
2373
2374         ac->ac_bits_given += *num_clusters;
2375
2376 bail:
2377         if (status)
2378                 mlog_errno(status);
2379         return status;
2380 }
2381
2382 int ocfs2_claim_clusters(handle_t *handle,
2383                          struct ocfs2_alloc_context *ac,
2384                          u32 min_clusters,
2385                          u32 *cluster_start,
2386                          u32 *num_clusters)
2387 {
2388         unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
2389
2390         return __ocfs2_claim_clusters(handle, ac, min_clusters,
2391                                       bits_wanted, cluster_start, num_clusters);
2392 }
2393
2394 static int ocfs2_block_group_clear_bits(handle_t *handle,
2395                                         struct inode *alloc_inode,
2396                                         struct ocfs2_group_desc *bg,
2397                                         struct buffer_head *group_bh,
2398                                         unsigned int bit_off,
2399                                         unsigned int num_bits,
2400                                         void (*undo_fn)(unsigned int bit,
2401                                                         unsigned long *bmap))
2402 {
2403         int status;
2404         unsigned int tmp;
2405         struct ocfs2_group_desc *undo_bg = NULL;
2406
2407         /* The caller got this descriptor from
2408          * ocfs2_read_group_descriptor().  Any corruption is a code bug. */
2409         BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
2410
2411         trace_ocfs2_block_group_clear_bits(bit_off, num_bits);
2412
2413         BUG_ON(undo_fn && !ocfs2_is_cluster_bitmap(alloc_inode));
2414         status = ocfs2_journal_access_gd(handle, INODE_CACHE(alloc_inode),
2415                                          group_bh,
2416                                          undo_fn ?
2417                                          OCFS2_JOURNAL_ACCESS_UNDO :
2418                                          OCFS2_JOURNAL_ACCESS_WRITE);
2419         if (status < 0) {
2420                 mlog_errno(status);
2421                 goto bail;
2422         }
2423
2424         if (undo_fn) {
2425                 jbd_lock_bh_state(group_bh);
2426                 undo_bg = (struct ocfs2_group_desc *)
2427                                         bh2jh(group_bh)->b_committed_data;
2428                 BUG_ON(!undo_bg);
2429         }
2430
2431         tmp = num_bits;
2432         while(tmp--) {
2433                 ocfs2_clear_bit((bit_off + tmp),
2434                                 (unsigned long *) bg->bg_bitmap);
2435                 if (undo_fn)
2436                         undo_fn(bit_off + tmp,
2437                                 (unsigned long *) undo_bg->bg_bitmap);
2438         }
2439         le16_add_cpu(&bg->bg_free_bits_count, num_bits);
2440         if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
2441                 if (undo_fn)
2442                         jbd_unlock_bh_state(group_bh);
2443                 return ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit count %u but claims %u are freed. num_bits %d\n",
2444                                    (unsigned long long)le64_to_cpu(bg->bg_blkno),
2445                                    le16_to_cpu(bg->bg_bits),
2446                                    le16_to_cpu(bg->bg_free_bits_count),
2447                                    num_bits);
2448         }
2449
2450         if (undo_fn)
2451                 jbd_unlock_bh_state(group_bh);
2452
2453         ocfs2_journal_dirty(handle, group_bh);
2454 bail:
2455         return status;
2456 }
2457
2458 /*
2459  * expects the suballoc inode to already be locked.
2460  */
2461 static int _ocfs2_free_suballoc_bits(handle_t *handle,
2462                                      struct inode *alloc_inode,
2463                                      struct buffer_head *alloc_bh,
2464                                      unsigned int start_bit,
2465                                      u64 bg_blkno,
2466                                      unsigned int count,
2467                                      void (*undo_fn)(unsigned int bit,
2468                                                      unsigned long *bitmap))
2469 {
2470         int status = 0;
2471         u32 tmp_used;
2472         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
2473         struct ocfs2_chain_list *cl = &fe->id2.i_chain;
2474         struct buffer_head *group_bh = NULL;
2475         struct ocfs2_group_desc *group;
2476
2477         /* The alloc_bh comes from ocfs2_free_dinode() or
2478          * ocfs2_free_clusters().  The callers have all locked the
2479          * allocator and gotten alloc_bh from the lock call.  This
2480          * validates the dinode buffer.  Any corruption that has happened
2481          * is a code bug. */
2482         BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
2483         BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
2484
2485         trace_ocfs2_free_suballoc_bits(
2486                 (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno,
2487                 (unsigned long long)bg_blkno,
2488                 start_bit, count);
2489
2490         status = ocfs2_read_group_descriptor(alloc_inode, fe, bg_blkno,
2491                                              &group_bh);
2492         if (status < 0) {
2493                 mlog_errno(status);
2494                 goto bail;
2495         }
2496         group = (struct ocfs2_group_desc *) group_bh->b_data;
2497
2498         BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
2499
2500         status = ocfs2_block_group_clear_bits(handle, alloc_inode,
2501                                               group, group_bh,
2502                                               start_bit, count, undo_fn);
2503         if (status < 0) {
2504                 mlog_errno(status);
2505                 goto bail;
2506         }
2507
2508         status = ocfs2_journal_access_di(handle, INODE_CACHE(alloc_inode),
2509                                          alloc_bh, OCFS2_JOURNAL_ACCESS_WRITE);
2510         if (status < 0) {
2511                 mlog_errno(status);
2512                 ocfs2_block_group_set_bits(handle, alloc_inode, group, group_bh,
2513                                 start_bit, count);
2514                 goto bail;
2515         }
2516
2517         le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
2518                      count);
2519         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
2520         fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
2521         ocfs2_journal_dirty(handle, alloc_bh);
2522
2523 bail:
2524         brelse(group_bh);
2525
2526         if (status)
2527                 mlog_errno(status);
2528         return status;
2529 }
2530
2531 int ocfs2_free_suballoc_bits(handle_t *handle,
2532                              struct inode *alloc_inode,
2533                              struct buffer_head *alloc_bh,
2534                              unsigned int start_bit,
2535                              u64 bg_blkno,
2536                              unsigned int count)
2537 {
2538         return _ocfs2_free_suballoc_bits(handle, alloc_inode, alloc_bh,
2539                                          start_bit, bg_blkno, count, NULL);
2540 }
2541
2542 int ocfs2_free_dinode(handle_t *handle,
2543                       struct inode *inode_alloc_inode,
2544                       struct buffer_head *inode_alloc_bh,
2545                       struct ocfs2_dinode *di)
2546 {
2547         u64 blk = le64_to_cpu(di->i_blkno);
2548         u16 bit = le16_to_cpu(di->i_suballoc_bit);
2549         u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
2550
2551         if (di->i_suballoc_loc)
2552                 bg_blkno = le64_to_cpu(di->i_suballoc_loc);
2553         return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
2554                                         inode_alloc_bh, bit, bg_blkno, 1);
2555 }
2556
2557 static int _ocfs2_free_clusters(handle_t *handle,
2558                                 struct inode *bitmap_inode,
2559                                 struct buffer_head *bitmap_bh,
2560                                 u64 start_blk,
2561                                 unsigned int num_clusters,
2562                                 void (*undo_fn)(unsigned int bit,
2563                                                 unsigned long *bitmap))
2564 {
2565         int status;
2566         u16 bg_start_bit;
2567         u64 bg_blkno;
2568
2569         /* You can't ever have a contiguous set of clusters
2570          * bigger than a block group bitmap so we never have to worry
2571          * about looping on them.
2572          * This is expensive. We can safely remove once this stuff has
2573          * gotten tested really well. */
2574         BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb,
2575                                 ocfs2_blocks_to_clusters(bitmap_inode->i_sb,
2576                                                          start_blk)));
2577
2578
2579         ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
2580                                      &bg_start_bit);
2581
2582         trace_ocfs2_free_clusters((unsigned long long)bg_blkno,
2583                         (unsigned long long)start_blk,
2584                         bg_start_bit, num_clusters);
2585
2586         status = _ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
2587                                            bg_start_bit, bg_blkno,
2588                                            num_clusters, undo_fn);
2589         if (status < 0) {
2590                 mlog_errno(status);
2591                 goto out;
2592         }
2593
2594         ocfs2_local_alloc_seen_free_bits(OCFS2_SB(bitmap_inode->i_sb),
2595                                          num_clusters);
2596
2597 out:
2598         if (status)
2599                 mlog_errno(status);
2600         return status;
2601 }
2602
2603 int ocfs2_free_clusters(handle_t *handle,
2604                         struct inode *bitmap_inode,
2605                         struct buffer_head *bitmap_bh,
2606                         u64 start_blk,
2607                         unsigned int num_clusters)
2608 {
2609         return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2610                                     start_blk, num_clusters,
2611                                     _ocfs2_set_bit);
2612 }
2613
2614 /*
2615  * Give never-used clusters back to the global bitmap.  We don't need
2616  * to protect these bits in the undo buffer.
2617  */
2618 int ocfs2_release_clusters(handle_t *handle,
2619                            struct inode *bitmap_inode,
2620                            struct buffer_head *bitmap_bh,
2621                            u64 start_blk,
2622                            unsigned int num_clusters)
2623 {
2624         return _ocfs2_free_clusters(handle, bitmap_inode, bitmap_bh,
2625                                     start_blk, num_clusters,
2626                                     _ocfs2_clear_bit);
2627 }
2628
2629 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg)
2630 {
2631         printk("Block Group:\n");
2632         printk("bg_signature:       %s\n", bg->bg_signature);
2633         printk("bg_size:            %u\n", bg->bg_size);
2634         printk("bg_bits:            %u\n", bg->bg_bits);
2635         printk("bg_free_bits_count: %u\n", bg->bg_free_bits_count);
2636         printk("bg_chain:           %u\n", bg->bg_chain);
2637         printk("bg_generation:      %u\n", le32_to_cpu(bg->bg_generation));
2638         printk("bg_next_group:      %llu\n",
2639                (unsigned long long)bg->bg_next_group);
2640         printk("bg_parent_dinode:   %llu\n",
2641                (unsigned long long)bg->bg_parent_dinode);
2642         printk("bg_blkno:           %llu\n",
2643                (unsigned long long)bg->bg_blkno);
2644 }
2645
2646 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe)
2647 {
2648         int i;
2649
2650         printk("Suballoc Inode %llu:\n", (unsigned long long)fe->i_blkno);
2651         printk("i_signature:                  %s\n", fe->i_signature);
2652         printk("i_size:                       %llu\n",
2653                (unsigned long long)fe->i_size);
2654         printk("i_clusters:                   %u\n", fe->i_clusters);
2655         printk("i_generation:                 %u\n",
2656                le32_to_cpu(fe->i_generation));
2657         printk("id1.bitmap1.i_used:           %u\n",
2658                le32_to_cpu(fe->id1.bitmap1.i_used));
2659         printk("id1.bitmap1.i_total:          %u\n",
2660                le32_to_cpu(fe->id1.bitmap1.i_total));
2661         printk("id2.i_chain.cl_cpg:           %u\n", fe->id2.i_chain.cl_cpg);
2662         printk("id2.i_chain.cl_bpc:           %u\n", fe->id2.i_chain.cl_bpc);
2663         printk("id2.i_chain.cl_count:         %u\n", fe->id2.i_chain.cl_count);
2664         printk("id2.i_chain.cl_next_free_rec: %u\n",
2665                fe->id2.i_chain.cl_next_free_rec);
2666         for(i = 0; i < fe->id2.i_chain.cl_next_free_rec; i++) {
2667                 printk("fe->id2.i_chain.cl_recs[%d].c_free:  %u\n", i,
2668                        fe->id2.i_chain.cl_recs[i].c_free);
2669                 printk("fe->id2.i_chain.cl_recs[%d].c_total: %u\n", i,
2670                        fe->id2.i_chain.cl_recs[i].c_total);
2671                 printk("fe->id2.i_chain.cl_recs[%d].c_blkno: %llu\n", i,
2672                        (unsigned long long)fe->id2.i_chain.cl_recs[i].c_blkno);
2673         }
2674 }
2675
2676 /*
2677  * For a given allocation, determine which allocators will need to be
2678  * accessed, and lock them, reserving the appropriate number of bits.
2679  *
2680  * Sparse file systems call this from ocfs2_write_begin_nolock()
2681  * and ocfs2_allocate_unwritten_extents().
2682  *
2683  * File systems which don't support holes call this from
2684  * ocfs2_extend_allocation().
2685  */
2686 int ocfs2_lock_allocators(struct inode *inode,
2687                           struct ocfs2_extent_tree *et,
2688                           u32 clusters_to_add, u32 extents_to_split,
2689                           struct ocfs2_alloc_context **data_ac,
2690                           struct ocfs2_alloc_context **meta_ac)
2691 {
2692         int ret = 0, num_free_extents;
2693         unsigned int max_recs_needed = clusters_to_add + 2 * extents_to_split;
2694         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
2695
2696         *meta_ac = NULL;
2697         if (data_ac)
2698                 *data_ac = NULL;
2699
2700         BUG_ON(clusters_to_add != 0 && data_ac == NULL);
2701
2702         num_free_extents = ocfs2_num_free_extents(et);
2703         if (num_free_extents < 0) {
2704                 ret = num_free_extents;
2705                 mlog_errno(ret);
2706                 goto out;
2707         }
2708
2709         /*
2710          * Sparse allocation file systems need to be more conservative
2711          * with reserving room for expansion - the actual allocation
2712          * happens while we've got a journal handle open so re-taking
2713          * a cluster lock (because we ran out of room for another
2714          * extent) will violate ordering rules.
2715          *
2716          * Most of the time we'll only be seeing this 1 cluster at a time
2717          * anyway.
2718          *
2719          * Always lock for any unwritten extents - we might want to
2720          * add blocks during a split.
2721          */
2722         if (!num_free_extents ||
2723             (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed)) {
2724                 ret = ocfs2_reserve_new_metadata(osb, et->et_root_el, meta_ac);
2725                 if (ret < 0) {
2726                         if (ret != -ENOSPC)
2727                                 mlog_errno(ret);
2728                         goto out;
2729                 }
2730         }
2731
2732         if (clusters_to_add == 0)
2733                 goto out;
2734
2735         ret = ocfs2_reserve_clusters(osb, clusters_to_add, data_ac);
2736         if (ret < 0) {
2737                 if (ret != -ENOSPC)
2738                         mlog_errno(ret);
2739                 goto out;
2740         }
2741
2742 out:
2743         if (ret) {
2744                 if (*meta_ac) {
2745                         ocfs2_free_alloc_context(*meta_ac);
2746                         *meta_ac = NULL;
2747                 }
2748
2749                 /*
2750                  * We cannot have an error and a non null *data_ac.
2751                  */
2752         }
2753
2754         return ret;
2755 }
2756
2757 /*
2758  * Read the inode specified by blkno to get suballoc_slot and
2759  * suballoc_bit.
2760  */
2761 static int ocfs2_get_suballoc_slot_bit(struct ocfs2_super *osb, u64 blkno,
2762                                        u16 *suballoc_slot, u64 *group_blkno,
2763                                        u16 *suballoc_bit)
2764 {
2765         int status;
2766         struct buffer_head *inode_bh = NULL;
2767         struct ocfs2_dinode *inode_fe;
2768
2769         trace_ocfs2_get_suballoc_slot_bit((unsigned long long)blkno);
2770
2771         /* dirty read disk */
2772         status = ocfs2_read_blocks_sync(osb, blkno, 1, &inode_bh);
2773         if (status < 0) {
2774                 mlog(ML_ERROR, "read block %llu failed %d\n",
2775                      (unsigned long long)blkno, status);
2776                 goto bail;
2777         }
2778
2779         inode_fe = (struct ocfs2_dinode *) inode_bh->b_data;
2780         if (!OCFS2_IS_VALID_DINODE(inode_fe)) {
2781                 mlog(ML_ERROR, "invalid inode %llu requested\n",
2782                      (unsigned long long)blkno);
2783                 status = -EINVAL;
2784                 goto bail;
2785         }
2786
2787         if (le16_to_cpu(inode_fe->i_suballoc_slot) != (u16)OCFS2_INVALID_SLOT &&
2788             (u32)le16_to_cpu(inode_fe->i_suballoc_slot) > osb->max_slots - 1) {
2789                 mlog(ML_ERROR, "inode %llu has invalid suballoc slot %u\n",
2790                      (unsigned long long)blkno,
2791                      (u32)le16_to_cpu(inode_fe->i_suballoc_slot));
2792                 status = -EINVAL;
2793                 goto bail;
2794         }
2795
2796         if (suballoc_slot)
2797                 *suballoc_slot = le16_to_cpu(inode_fe->i_suballoc_slot);
2798         if (suballoc_bit)
2799                 *suballoc_bit = le16_to_cpu(inode_fe->i_suballoc_bit);
2800         if (group_blkno)
2801                 *group_blkno = le64_to_cpu(inode_fe->i_suballoc_loc);
2802
2803 bail:
2804         brelse(inode_bh);
2805
2806         if (status)
2807                 mlog_errno(status);
2808         return status;
2809 }
2810
2811 /*
2812  * test whether bit is SET in allocator bitmap or not.  on success, 0
2813  * is returned and *res is 1 for SET; 0 otherwise.  when fails, errno
2814  * is returned and *res is meaningless.  Call this after you have
2815  * cluster locked against suballoc, or you may get a result based on
2816  * non-up2date contents
2817  */
2818 static int ocfs2_test_suballoc_bit(struct ocfs2_super *osb,
2819                                    struct inode *suballoc,
2820                                    struct buffer_head *alloc_bh,
2821                                    u64 group_blkno, u64 blkno,
2822                                    u16 bit, int *res)
2823 {
2824         struct ocfs2_dinode *alloc_di;
2825         struct ocfs2_group_desc *group;
2826         struct buffer_head *group_bh = NULL;
2827         u64 bg_blkno;
2828         int status;
2829
2830         trace_ocfs2_test_suballoc_bit((unsigned long long)blkno,
2831                                       (unsigned int)bit);
2832
2833         alloc_di = (struct ocfs2_dinode *)alloc_bh->b_data;
2834         if ((bit + 1) > ocfs2_bits_per_group(&alloc_di->id2.i_chain)) {
2835                 mlog(ML_ERROR, "suballoc bit %u out of range of %u\n",
2836                      (unsigned int)bit,
2837                      ocfs2_bits_per_group(&alloc_di->id2.i_chain));
2838                 status = -EINVAL;
2839                 goto bail;
2840         }
2841
2842         bg_blkno = group_blkno ? group_blkno :
2843                    ocfs2_which_suballoc_group(blkno, bit);
2844         status = ocfs2_read_group_descriptor(suballoc, alloc_di, bg_blkno,
2845                                              &group_bh);
2846         if (status < 0) {
2847                 mlog(ML_ERROR, "read group %llu failed %d\n",
2848                      (unsigned long long)bg_blkno, status);
2849                 goto bail;
2850         }
2851
2852         group = (struct ocfs2_group_desc *) group_bh->b_data;
2853         *res = ocfs2_test_bit(bit, (unsigned long *)group->bg_bitmap);
2854
2855 bail:
2856         brelse(group_bh);
2857
2858         if (status)
2859                 mlog_errno(status);
2860         return status;
2861 }
2862
2863 /*
2864  * Test if the bit representing this inode (blkno) is set in the
2865  * suballocator.
2866  *
2867  * On success, 0 is returned and *res is 1 for SET; 0 otherwise.
2868  *
2869  * In the event of failure, a negative value is returned and *res is
2870  * meaningless.
2871  *
2872  * Callers must make sure to hold nfs_sync_lock to prevent
2873  * ocfs2_delete_inode() on another node from accessing the same
2874  * suballocator concurrently.
2875  */
2876 int ocfs2_test_inode_bit(struct ocfs2_super *osb, u64 blkno, int *res)
2877 {
2878         int status;
2879         u64 group_blkno = 0;
2880         u16 suballoc_bit = 0, suballoc_slot = 0;
2881         struct inode *inode_alloc_inode;
2882         struct buffer_head *alloc_bh = NULL;
2883
2884         trace_ocfs2_test_inode_bit((unsigned long long)blkno);
2885
2886         status = ocfs2_get_suballoc_slot_bit(osb, blkno, &suballoc_slot,
2887                                              &group_blkno, &suballoc_bit);
2888         if (status < 0) {
2889                 mlog(ML_ERROR, "get alloc slot and bit failed %d\n", status);
2890                 goto bail;
2891         }
2892
2893         inode_alloc_inode =
2894                 ocfs2_get_system_file_inode(osb, INODE_ALLOC_SYSTEM_INODE,
2895                                             suballoc_slot);
2896         if (!inode_alloc_inode) {
2897                 /* the error code could be inaccurate, but we are not able to
2898                  * get the correct one. */
2899                 status = -EINVAL;
2900                 mlog(ML_ERROR, "unable to get alloc inode in slot %u\n",
2901                      (u32)suballoc_slot);
2902                 goto bail;
2903         }
2904
2905         inode_lock(inode_alloc_inode);
2906         status = ocfs2_inode_lock(inode_alloc_inode, &alloc_bh, 0);
2907         if (status < 0) {
2908                 inode_unlock(inode_alloc_inode);
2909                 iput(inode_alloc_inode);
2910                 mlog(ML_ERROR, "lock on alloc inode on slot %u failed %d\n",
2911                      (u32)suballoc_slot, status);
2912                 goto bail;
2913         }
2914
2915         status = ocfs2_test_suballoc_bit(osb, inode_alloc_inode, alloc_bh,
2916                                          group_blkno, blkno, suballoc_bit, res);
2917         if (status < 0)
2918                 mlog(ML_ERROR, "test suballoc bit failed %d\n", status);
2919
2920         ocfs2_inode_unlock(inode_alloc_inode, 0);
2921         inode_unlock(inode_alloc_inode);
2922
2923         iput(inode_alloc_inode);
2924         brelse(alloc_bh);
2925 bail:
2926         if (status)
2927                 mlog_errno(status);
2928         return status;
2929 }