kernel/fs/ocfs2/refcounttree.c

   1 /* -*- mode: c; c-basic-offset: 8; -*-
   2  * vim: noexpandtab sw=8 ts=8 sts=0:
   3  *
   4  * refcounttree.c
   5  *
   6  * Copyright (C) 2009 Oracle.  All rights reserved.
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public
  10  * License version 2 as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  */
  17
  18 #include <linux/sort.h>
  19 #include <cluster/masklog.h>
  20 #include "ocfs2.h"
  21 #include "inode.h"
  22 #include "alloc.h"
  23 #include "suballoc.h"
  24 #include "journal.h"
  25 #include "uptodate.h"
  26 #include "super.h"
  27 #include "buffer_head_io.h"
  28 #include "blockcheck.h"
  29 #include "refcounttree.h"
  30 #include "sysfile.h"
  31 #include "dlmglue.h"
  32 #include "extent_map.h"
  33 #include "aops.h"
  34 #include "xattr.h"
  35 #include "namei.h"
  36 #include "ocfs2_trace.h"
  37
  38 #include <linux/bio.h>
  39 #include <linux/blkdev.h>
  40 #include <linux/slab.h>
  41 #include <linux/writeback.h>
  42 #include <linux/pagevec.h>
  43 #include <linux/swap.h>
  44 #include <linux/security.h>
  45 #include <linux/fsnotify.h>
  46 #include <linux/quotaops.h>
  47 #include <linux/namei.h>
  48 #include <linux/mount.h>
  49 #include <linux/posix_acl.h>
  50
  51 struct ocfs2_cow_context {
  52         struct inode *inode;
  53         u32 cow_start;
  54         u32 cow_len;
  55         struct ocfs2_extent_tree data_et;
  56         struct ocfs2_refcount_tree *ref_tree;
  57         struct buffer_head *ref_root_bh;
  58         struct ocfs2_alloc_context *meta_ac;
  59         struct ocfs2_alloc_context *data_ac;
  60         struct ocfs2_cached_dealloc_ctxt dealloc;
  61         void *cow_object;
  62         struct ocfs2_post_refcount *post_refcount;
  63         int extra_credits;
  64         int (*get_clusters)(struct ocfs2_cow_context *context,
  65                             u32 v_cluster, u32 *p_cluster,
  66                             u32 *num_clusters,
  67                             unsigned int *extent_flags);
  68         int (*cow_duplicate_clusters)(handle_t *handle,
  69                                       struct inode *inode,
  70                                       u32 cpos, u32 old_cluster,
  71                                       u32 new_cluster, u32 new_len);
  72 };
  73
  74 static inline struct ocfs2_refcount_tree *
  75 cache_info_to_refcount(struct ocfs2_caching_info *ci)
  76 {
  77         return container_of(ci, struct ocfs2_refcount_tree, rf_ci);
  78 }
  79
  80 static int ocfs2_validate_refcount_block(struct super_block *sb,
  81                                          struct buffer_head *bh)
  82 {
  83         int rc;
  84         struct ocfs2_refcount_block *rb =
  85                 (struct ocfs2_refcount_block *)bh->b_data;
  86
  87         trace_ocfs2_validate_refcount_block((unsigned long long)bh->b_blocknr);
  88
  89         BUG_ON(!buffer_uptodate(bh));
  90
  91         /*
  92          * If the ecc fails, we return the error but otherwise
  93          * leave the filesystem running.  We know any error is
  94          * local to this block.
  95          */
  96         rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &rb->rf_check);
  97         if (rc) {
  98                 mlog(ML_ERROR, "Checksum failed for refcount block %llu\n",
  99                      (unsigned long long)bh->b_blocknr);
 100                 return rc;
 101         }
 102
 103
 104         if (!OCFS2_IS_VALID_REFCOUNT_BLOCK(rb)) {
 105                 ocfs2_error(sb,
 106                             "Refcount block #%llu has bad signature %.*s",
 107                             (unsigned long long)bh->b_blocknr, 7,
 108                             rb->rf_signature);
 109                 return -EINVAL;
 110         }
 111
 112         if (le64_to_cpu(rb->rf_blkno) != bh->b_blocknr) {
 113                 ocfs2_error(sb,
 114                             "Refcount block #%llu has an invalid rf_blkno "
 115                             "of %llu",
 116                             (unsigned long long)bh->b_blocknr,
 117                             (unsigned long long)le64_to_cpu(rb->rf_blkno));
 118                 return -EINVAL;
 119         }
 120
 121         if (le32_to_cpu(rb->rf_fs_generation) != OCFS2_SB(sb)->fs_generation) {
 122                 ocfs2_error(sb,
 123                             "Refcount block #%llu has an invalid "
 124                             "rf_fs_generation of #%u",
 125                             (unsigned long long)bh->b_blocknr,
 126                             le32_to_cpu(rb->rf_fs_generation));
 127                 return -EINVAL;
 128         }
 129
 130         return 0;
 131 }
 132
 133 static int ocfs2_read_refcount_block(struct ocfs2_caching_info *ci,
 134                                      u64 rb_blkno,
 135                                      struct buffer_head **bh)
 136 {
 137         int rc;
 138         struct buffer_head *tmp = *bh;
 139
 140         rc = ocfs2_read_block(ci, rb_blkno, &tmp,
 141                               ocfs2_validate_refcount_block);
 142
 143         /* If ocfs2_read_block() got us a new bh, pass it up. */
 144         if (!rc && !*bh)
 145                 *bh = tmp;
 146
 147         return rc;
 148 }
 149
 150 static u64 ocfs2_refcount_cache_owner(struct ocfs2_caching_info *ci)
 151 {
 152         struct ocfs2_refcount_tree *rf = cache_info_to_refcount(ci);
 153
 154         return rf->rf_blkno;
 155 }
 156
 157 static struct super_block *
 158 ocfs2_refcount_cache_get_super(struct ocfs2_caching_info *ci)
 159 {
 160         struct ocfs2_refcount_tree *rf = cache_info_to_refcount(ci);
 161
 162         return rf->rf_sb;
 163 }
 164
 165 static void ocfs2_refcount_cache_lock(struct ocfs2_caching_info *ci)
 166 {
 167         struct ocfs2_refcount_tree *rf = cache_info_to_refcount(ci);
 168
 169         spin_lock(&rf->rf_lock);
 170 }
 171
 172 static void ocfs2_refcount_cache_unlock(struct ocfs2_caching_info *ci)
 173 {
 174         struct ocfs2_refcount_tree *rf = cache_info_to_refcount(ci);
 175
 176         spin_unlock(&rf->rf_lock);
 177 }
 178
 179 static void ocfs2_refcount_cache_io_lock(struct ocfs2_caching_info *ci)
 180 {
 181         struct ocfs2_refcount_tree *rf = cache_info_to_refcount(ci);
 182
 183         mutex_lock(&rf->rf_io_mutex);
 184 }
 185
 186 static void ocfs2_refcount_cache_io_unlock(struct ocfs2_caching_info *ci)
 187 {
 188         struct ocfs2_refcount_tree *rf = cache_info_to_refcount(ci);
 189
 190         mutex_unlock(&rf->rf_io_mutex);
 191 }
 192
 193 static const struct ocfs2_caching_operations ocfs2_refcount_caching_ops = {
 194         .co_owner               = ocfs2_refcount_cache_owner,
 195         .co_get_super           = ocfs2_refcount_cache_get_super,
 196         .co_cache_lock          = ocfs2_refcount_cache_lock,
 197         .co_cache_unlock        = ocfs2_refcount_cache_unlock,
 198         .co_io_lock             = ocfs2_refcount_cache_io_lock,
 199         .co_io_unlock           = ocfs2_refcount_cache_io_unlock,
 200 };
 201
 202 static struct ocfs2_refcount_tree *
 203 ocfs2_find_refcount_tree(struct ocfs2_super *osb, u64 blkno)
 204 {
 205         struct rb_node *n = osb->osb_rf_lock_tree.rb_node;
 206         struct ocfs2_refcount_tree *tree = NULL;
 207
 208         while (n) {
 209                 tree = rb_entry(n, struct ocfs2_refcount_tree, rf_node);
 210
 211                 if (blkno < tree->rf_blkno)
 212                         n = n->rb_left;
 213                 else if (blkno > tree->rf_blkno)
 214                         n = n->rb_right;
 215                 else
 216                         return tree;
 217         }
 218
 219         return NULL;
 220 }
 221
 222 /* osb_lock is already locked. */
 223 static void ocfs2_insert_refcount_tree(struct ocfs2_super *osb,
 224                                        struct ocfs2_refcount_tree *new)
 225 {
 226         u64 rf_blkno = new->rf_blkno;
 227         struct rb_node *parent = NULL;
 228         struct rb_node **p = &osb->osb_rf_lock_tree.rb_node;
 229         struct ocfs2_refcount_tree *tmp;
 230
 231         while (*p) {
 232                 parent = *p;
 233
 234                 tmp = rb_entry(parent, struct ocfs2_refcount_tree,
 235                                rf_node);
 236
 237                 if (rf_blkno < tmp->rf_blkno)
 238                         p = &(*p)->rb_left;
 239                 else if (rf_blkno > tmp->rf_blkno)
 240                         p = &(*p)->rb_right;
 241                 else {
 242                         /* This should never happen! */
 243                         mlog(ML_ERROR, "Duplicate refcount block %llu found!\n",
 244                              (unsigned long long)rf_blkno);
 245                         BUG();
 246                 }
 247         }
 248
 249         rb_link_node(&new->rf_node, parent, p);
 250         rb_insert_color(&new->rf_node, &osb->osb_rf_lock_tree);
 251 }
 252
 253 static void ocfs2_free_refcount_tree(struct ocfs2_refcount_tree *tree)
 254 {
 255         ocfs2_metadata_cache_exit(&tree->rf_ci);
 256         ocfs2_simple_drop_lockres(OCFS2_SB(tree->rf_sb), &tree->rf_lockres);
 257         ocfs2_lock_res_free(&tree->rf_lockres);
 258         kfree(tree);
 259 }
 260
 261 static inline void
 262 ocfs2_erase_refcount_tree_from_list_no_lock(struct ocfs2_super *osb,
 263                                         struct ocfs2_refcount_tree *tree)
 264 {
 265         rb_erase(&tree->rf_node, &osb->osb_rf_lock_tree);
 266         if (osb->osb_ref_tree_lru && osb->osb_ref_tree_lru == tree)
 267                 osb->osb_ref_tree_lru = NULL;
 268 }
 269
 270 static void ocfs2_erase_refcount_tree_from_list(struct ocfs2_super *osb,
 271                                         struct ocfs2_refcount_tree *tree)
 272 {
 273         spin_lock(&osb->osb_lock);
 274         ocfs2_erase_refcount_tree_from_list_no_lock(osb, tree);
 275         spin_unlock(&osb->osb_lock);
 276 }
 277
 278 static void ocfs2_kref_remove_refcount_tree(struct kref *kref)
 279 {
 280         struct ocfs2_refcount_tree *tree =
 281                 container_of(kref, struct ocfs2_refcount_tree, rf_getcnt);
 282
 283         ocfs2_free_refcount_tree(tree);
 284 }
 285
 286 static inline void
 287 ocfs2_refcount_tree_get(struct ocfs2_refcount_tree *tree)
 288 {
 289         kref_get(&tree->rf_getcnt);
 290 }
 291
 292 static inline void
 293 ocfs2_refcount_tree_put(struct ocfs2_refcount_tree *tree)
 294 {
 295         kref_put(&tree->rf_getcnt, ocfs2_kref_remove_refcount_tree);
 296 }
 297
 298 static inline void ocfs2_init_refcount_tree_ci(struct ocfs2_refcount_tree *new,
 299                                                struct super_block *sb)
 300 {
 301         ocfs2_metadata_cache_init(&new->rf_ci, &ocfs2_refcount_caching_ops);
 302         mutex_init(&new->rf_io_mutex);
 303         new->rf_sb = sb;
 304         spin_lock_init(&new->rf_lock);
 305 }
 306
 307 static inline void ocfs2_init_refcount_tree_lock(struct ocfs2_super *osb,
 308                                         struct ocfs2_refcount_tree *new,
 309                                         u64 rf_blkno, u32 generation)
 310 {
 311         init_rwsem(&new->rf_sem);
 312         ocfs2_refcount_lock_res_init(&new->rf_lockres, osb,
 313                                      rf_blkno, generation);
 314 }
 315
 316 static struct ocfs2_refcount_tree*
 317 ocfs2_allocate_refcount_tree(struct ocfs2_super *osb, u64 rf_blkno)
 318 {
 319         struct ocfs2_refcount_tree *new;
 320
 321         new = kzalloc(sizeof(struct ocfs2_refcount_tree), GFP_NOFS);
 322         if (!new)
 323                 return NULL;
 324
 325         new->rf_blkno = rf_blkno;
 326         kref_init(&new->rf_getcnt);
 327         ocfs2_init_refcount_tree_ci(new, osb->sb);
 328
 329         return new;
 330 }
 331
 332 static int ocfs2_get_refcount_tree(struct ocfs2_super *osb, u64 rf_blkno,
 333                                    struct ocfs2_refcount_tree **ret_tree)
 334 {
 335         int ret = 0;
 336         struct ocfs2_refcount_tree *tree, *new = NULL;
 337         struct buffer_head *ref_root_bh = NULL;
 338         struct ocfs2_refcount_block *ref_rb;
 339
 340         spin_lock(&osb->osb_lock);
 341         if (osb->osb_ref_tree_lru &&
 342             osb->osb_ref_tree_lru->rf_blkno == rf_blkno)
 343                 tree = osb->osb_ref_tree_lru;
 344         else
 345                 tree = ocfs2_find_refcount_tree(osb, rf_blkno);
 346         if (tree)
 347                 goto out;
 348
 349         spin_unlock(&osb->osb_lock);
 350
 351         new = ocfs2_allocate_refcount_tree(osb, rf_blkno);
 352         if (!new) {
 353                 ret = -ENOMEM;
 354                 mlog_errno(ret);
 355                 return ret;
 356         }
 357         /*
 358          * We need the generation to create the refcount tree lock and since
 359          * it isn't changed during the tree modification, we are safe here to
 360          * read without protection.
 361          * We also have to purge the cache after we create the lock since the
 362          * refcount block may have the stale data. It can only be trusted when
 363          * we hold the refcount lock.
 364          */
 365         ret = ocfs2_read_refcount_block(&new->rf_ci, rf_blkno, &ref_root_bh);
 366         if (ret) {
 367                 mlog_errno(ret);
 368                 ocfs2_metadata_cache_exit(&new->rf_ci);
 369                 kfree(new);
 370                 return ret;
 371         }
 372
 373         ref_rb = (struct ocfs2_refcount_block *)ref_root_bh->b_data;
 374         new->rf_generation = le32_to_cpu(ref_rb->rf_generation);
 375         ocfs2_init_refcount_tree_lock(osb, new, rf_blkno,
 376                                       new->rf_generation);
 377         ocfs2_metadata_cache_purge(&new->rf_ci);
 378
 379         spin_lock(&osb->osb_lock);
 380         tree = ocfs2_find_refcount_tree(osb, rf_blkno);
 381         if (tree)
 382                 goto out;
 383
 384         ocfs2_insert_refcount_tree(osb, new);
 385
 386         tree = new;
 387         new = NULL;
 388
 389 out:
 390         *ret_tree = tree;
 391
 392         osb->osb_ref_tree_lru = tree;
 393
 394         spin_unlock(&osb->osb_lock);
 395
 396         if (new)
 397                 ocfs2_free_refcount_tree(new);
 398
 399         brelse(ref_root_bh);
 400         return ret;
 401 }
 402
 403 static int ocfs2_get_refcount_block(struct inode *inode, u64 *ref_blkno)
 404 {
 405         int ret;
 406         struct buffer_head *di_bh = NULL;
 407         struct ocfs2_dinode *di;
 408
 409         ret = ocfs2_read_inode_block(inode, &di_bh);
 410         if (ret) {
 411                 mlog_errno(ret);
 412                 goto out;
 413         }
 414
 415         BUG_ON(!(OCFS2_I(inode)->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL));
 416
 417         di = (struct ocfs2_dinode *)di_bh->b_data;
 418         *ref_blkno = le64_to_cpu(di->i_refcount_loc);
 419         brelse(di_bh);
 420 out:
 421         return ret;
 422 }
 423
 424 static int __ocfs2_lock_refcount_tree(struct ocfs2_super *osb,
 425                                       struct ocfs2_refcount_tree *tree, int rw)
 426 {
 427         int ret;
 428
 429         ret = ocfs2_refcount_lock(tree, rw);
 430         if (ret) {
 431                 mlog_errno(ret);
 432                 goto out;
 433         }
 434
 435         if (rw)
 436                 down_write(&tree->rf_sem);
 437         else
 438                 down_read(&tree->rf_sem);
 439
 440 out:
 441         return ret;
 442 }
 443
 444 /*
 445  * Lock the refcount tree pointed by ref_blkno and return the tree.
 446  * In most case, we lock the tree and read the refcount block.
 447  * So read it here if the caller really needs it.
 448  *
 449  * If the tree has been re-created by other node, it will free the
 450  * old one and re-create it.
 451  */
 452 int ocfs2_lock_refcount_tree(struct ocfs2_super *osb,
 453                              u64 ref_blkno, int rw,
 454                              struct ocfs2_refcount_tree **ret_tree,
 455                              struct buffer_head **ref_bh)
 456 {
 457         int ret, delete_tree = 0;
 458         struct ocfs2_refcount_tree *tree = NULL;
 459         struct buffer_head *ref_root_bh = NULL;
 460         struct ocfs2_refcount_block *rb;
 461
 462 again:
 463         ret = ocfs2_get_refcount_tree(osb, ref_blkno, &tree);
 464         if (ret) {
 465                 mlog_errno(ret);
 466                 return ret;
 467         }
 468
 469         ocfs2_refcount_tree_get(tree);
 470
 471         ret = __ocfs2_lock_refcount_tree(osb, tree, rw);
 472         if (ret) {
 473                 mlog_errno(ret);
 474                 ocfs2_refcount_tree_put(tree);
 475                 goto out;
 476         }
 477
 478         ret = ocfs2_read_refcount_block(&tree->rf_ci, tree->rf_blkno,
 479                                         &ref_root_bh);
 480         if (ret) {
 481                 mlog_errno(ret);
 482                 ocfs2_unlock_refcount_tree(osb, tree, rw);
 483                 ocfs2_refcount_tree_put(tree);
 484                 goto out;
 485         }
 486
 487         rb = (struct ocfs2_refcount_block *)ref_root_bh->b_data;
 488         /*
 489          * If the refcount block has been freed and re-created, we may need
 490          * to recreate the refcount tree also.
 491          *
 492          * Here we just remove the tree from the rb-tree, and the last
 493          * kref holder will unlock and delete this refcount_tree.
 494          * Then we goto "again" and ocfs2_get_refcount_tree will create
 495          * the new refcount tree for us.
 496          */
 497         if (tree->rf_generation != le32_to_cpu(rb->rf_generation)) {
 498                 if (!tree->rf_removed) {
 499                         ocfs2_erase_refcount_tree_from_list(osb, tree);
 500                         tree->rf_removed = 1;
 501                         delete_tree = 1;
 502                 }
 503
 504                 ocfs2_unlock_refcount_tree(osb, tree, rw);
 505                 /*
 506                  * We get an extra reference when we create the refcount
 507                  * tree, so another put will destroy it.
 508                  */
 509                 if (delete_tree)
 510                         ocfs2_refcount_tree_put(tree);
 511                 brelse(ref_root_bh);
 512                 ref_root_bh = NULL;
 513                 goto again;
 514         }
 515
 516         *ret_tree = tree;
 517         if (ref_bh) {
 518                 *ref_bh = ref_root_bh;
 519                 ref_root_bh = NULL;
 520         }
 521 out:
 522         brelse(ref_root_bh);
 523         return ret;
 524 }
 525
 526 void ocfs2_unlock_refcount_tree(struct ocfs2_super *osb,
 527                                 struct ocfs2_refcount_tree *tree, int rw)
 528 {
 529         if (rw)
 530                 up_write(&tree->rf_sem);
 531         else
 532                 up_read(&tree->rf_sem);
 533
 534         ocfs2_refcount_unlock(tree, rw);
 535         ocfs2_refcount_tree_put(tree);
 536 }
 537
 538 void ocfs2_purge_refcount_trees(struct ocfs2_super *osb)
 539 {
 540         struct rb_node *node;
 541         struct ocfs2_refcount_tree *tree;
 542         struct rb_root *root = &osb->osb_rf_lock_tree;
 543
 544         while ((node = rb_last(root)) != NULL) {
 545                 tree = rb_entry(node, struct ocfs2_refcount_tree, rf_node);
 546
 547                 trace_ocfs2_purge_refcount_trees(
 548                                 (unsigned long long) tree->rf_blkno);
 549
 550                 rb_erase(&tree->rf_node, root);
 551                 ocfs2_free_refcount_tree(tree);
 552         }
 553 }
 554
 555 /*
 556  * Create a refcount tree for an inode.
 557  * We take for granted that the inode is already locked.
 558  */
 559 static int ocfs2_create_refcount_tree(struct inode *inode,
 560                                       struct buffer_head *di_bh)
 561 {
 562         int ret;
 563         handle_t *handle = NULL;
 564         struct ocfs2_alloc_context *meta_ac = NULL;
 565         struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
 566         struct ocfs2_inode_info *oi = OCFS2_I(inode);
 567         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 568         struct buffer_head *new_bh = NULL;
 569         struct ocfs2_refcount_block *rb;
 570         struct ocfs2_refcount_tree *new_tree = NULL, *tree = NULL;
 571         u16 suballoc_bit_start;
 572         u32 num_got;
 573         u64 suballoc_loc, first_blkno;
 574
 575         BUG_ON(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL);
 576
 577         trace_ocfs2_create_refcount_tree(
 578                 (unsigned long long)OCFS2_I(inode)->ip_blkno);
 579
 580         ret = ocfs2_reserve_new_metadata_blocks(osb, 1, &meta_ac);
 581         if (ret) {
 582                 mlog_errno(ret);
 583                 goto out;
 584         }
 585
 586         handle = ocfs2_start_trans(osb, OCFS2_REFCOUNT_TREE_CREATE_CREDITS);
 587         if (IS_ERR(handle)) {
 588                 ret = PTR_ERR(handle);
 589                 mlog_errno(ret);
 590                 goto out;
 591         }
 592
 593         ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
 594                                       OCFS2_JOURNAL_ACCESS_WRITE);
 595         if (ret) {
 596                 mlog_errno(ret);
 597                 goto out_commit;
 598         }
 599
 600         ret = ocfs2_claim_metadata(handle, meta_ac, 1, &suballoc_loc,
 601                                    &suballoc_bit_start, &num_got,
 602                                    &first_blkno);
 603         if (ret) {
 604                 mlog_errno(ret);
 605                 goto out_commit;
 606         }
 607
 608         new_tree = ocfs2_allocate_refcount_tree(osb, first_blkno);
 609         if (!new_tree) {
 610                 ret = -ENOMEM;
 611                 mlog_errno(ret);
 612                 goto out_commit;
 613         }
 614
 615         new_bh = sb_getblk(inode->i_sb, first_blkno);
 616         if (!new_bh) {
 617                 ret = -ENOMEM;
 618                 mlog_errno(ret);
 619                 goto out_commit;
 620         }
 621         ocfs2_set_new_buffer_uptodate(&new_tree->rf_ci, new_bh);
 622
 623         ret = ocfs2_journal_access_rb(handle, &new_tree->rf_ci, new_bh,
 624                                       OCFS2_JOURNAL_ACCESS_CREATE);
 625         if (ret) {
 626                 mlog_errno(ret);
 627                 goto out_commit;
 628         }
 629
 630         /* Initialize ocfs2_refcount_block. */
 631         rb = (struct ocfs2_refcount_block *)new_bh->b_data;
 632         memset(rb, 0, inode->i_sb->s_blocksize);
 633         strcpy((void *)rb, OCFS2_REFCOUNT_BLOCK_SIGNATURE);
 634         rb->rf_suballoc_slot = cpu_to_le16(meta_ac->ac_alloc_slot);
 635         rb->rf_suballoc_loc = cpu_to_le64(suballoc_loc);
 636         rb->rf_suballoc_bit = cpu_to_le16(suballoc_bit_start);
 637         rb->rf_fs_generation = cpu_to_le32(osb->fs_generation);
 638         rb->rf_blkno = cpu_to_le64(first_blkno);
 639         rb->rf_count = cpu_to_le32(1);
 640         rb->rf_records.rl_count =
 641                         cpu_to_le16(ocfs2_refcount_recs_per_rb(osb->sb));
 642         spin_lock(&osb->osb_lock);
 643         rb->rf_generation = osb->s_next_generation++;
 644         spin_unlock(&osb->osb_lock);
 645
 646         ocfs2_journal_dirty(handle, new_bh);
 647
 648         spin_lock(&oi->ip_lock);
 649         oi->ip_dyn_features |= OCFS2_HAS_REFCOUNT_FL;
 650         di->i_dyn_features = cpu_to_le16(oi->ip_dyn_features);
 651         di->i_refcount_loc = cpu_to_le64(first_blkno);
 652         spin_unlock(&oi->ip_lock);
 653
 654         trace_ocfs2_create_refcount_tree_blkno((unsigned long long)first_blkno);
 655
 656         ocfs2_journal_dirty(handle, di_bh);
 657
 658         /*
 659          * We have to init the tree lock here since it will use
 660          * the generation number to create it.
 661          */
 662         new_tree->rf_generation = le32_to_cpu(rb->rf_generation);
 663         ocfs2_init_refcount_tree_lock(osb, new_tree, first_blkno,
 664                                       new_tree->rf_generation);
 665
 666         spin_lock(&osb->osb_lock);
 667         tree = ocfs2_find_refcount_tree(osb, first_blkno);
 668
 669         /*
 670          * We've just created a new refcount tree in this block.  If
 671          * we found a refcount tree on the ocfs2_super, it must be
 672          * one we just deleted.  We free the old tree before
 673          * inserting the new tree.
 674          */
 675         BUG_ON(tree && tree->rf_generation == new_tree->rf_generation);
 676         if (tree)
 677                 ocfs2_erase_refcount_tree_from_list_no_lock(osb, tree);
 678         ocfs2_insert_refcount_tree(osb, new_tree);
 679         spin_unlock(&osb->osb_lock);
 680         new_tree = NULL;
 681         if (tree)
 682                 ocfs2_refcount_tree_put(tree);
 683
 684 out_commit:
 685         ocfs2_commit_trans(osb, handle);
 686
 687 out:
 688         if (new_tree) {
 689                 ocfs2_metadata_cache_exit(&new_tree->rf_ci);
 690                 kfree(new_tree);
 691         }
 692
 693         brelse(new_bh);
 694         if (meta_ac)
 695                 ocfs2_free_alloc_context(meta_ac);
 696
 697         return ret;
 698 }
 699
 700 static int ocfs2_set_refcount_tree(struct inode *inode,
 701                                    struct buffer_head *di_bh,
 702                                    u64 refcount_loc)
 703 {
 704         int ret;
 705         handle_t *handle = NULL;
 706         struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
 707         struct ocfs2_inode_info *oi = OCFS2_I(inode);
 708         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 709         struct buffer_head *ref_root_bh = NULL;
 710         struct ocfs2_refcount_block *rb;
 711         struct ocfs2_refcount_tree *ref_tree;
 712
 713         BUG_ON(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL);
 714
 715         ret = ocfs2_lock_refcount_tree(osb, refcount_loc, 1,
 716                                        &ref_tree, &ref_root_bh);
 717         if (ret) {
 718                 mlog_errno(ret);
 719                 return ret;
 720         }
 721
 722         handle = ocfs2_start_trans(osb, OCFS2_REFCOUNT_TREE_SET_CREDITS);
 723         if (IS_ERR(handle)) {
 724                 ret = PTR_ERR(handle);
 725                 mlog_errno(ret);
 726                 goto out;
 727         }
 728
 729         ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
 730                                       OCFS2_JOURNAL_ACCESS_WRITE);
 731         if (ret) {
 732                 mlog_errno(ret);
 733                 goto out_commit;
 734         }
 735
 736         ret = ocfs2_journal_access_rb(handle, &ref_tree->rf_ci, ref_root_bh,
 737                                       OCFS2_JOURNAL_ACCESS_WRITE);
 738         if (ret) {
 739                 mlog_errno(ret);
 740                 goto out_commit;
 741         }
 742
 743         rb = (struct ocfs2_refcount_block *)ref_root_bh->b_data;
 744         le32_add_cpu(&rb->rf_count, 1);
 745
 746         ocfs2_journal_dirty(handle, ref_root_bh);
 747
 748         spin_lock(&oi->ip_lock);
 749         oi->ip_dyn_features |= OCFS2_HAS_REFCOUNT_FL;
 750         di->i_dyn_features = cpu_to_le16(oi->ip_dyn_features);
 751         di->i_refcount_loc = cpu_to_le64(refcount_loc);
 752         spin_unlock(&oi->ip_lock);
 753         ocfs2_journal_dirty(handle, di_bh);
 754
 755 out_commit:
 756         ocfs2_commit_trans(osb, handle);
 757 out:
 758         ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
 759         brelse(ref_root_bh);
 760
 761         return ret;
 762 }
 763
 764 int ocfs2_remove_refcount_tree(struct inode *inode, struct buffer_head *di_bh)
 765 {
 766         int ret, delete_tree = 0;
 767         handle_t *handle = NULL;
 768         struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
 769         struct ocfs2_inode_info *oi = OCFS2_I(inode);
 770         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 771         struct ocfs2_refcount_block *rb;
 772         struct inode *alloc_inode = NULL;
 773         struct buffer_head *alloc_bh = NULL;
 774         struct buffer_head *blk_bh = NULL;
 775         struct ocfs2_refcount_tree *ref_tree;
 776         int credits = OCFS2_REFCOUNT_TREE_REMOVE_CREDITS;
 777         u64 blk = 0, bg_blkno = 0, ref_blkno = le64_to_cpu(di->i_refcount_loc);
 778         u16 bit = 0;
 779
 780         if (!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL))
 781                 return 0;
 782
 783         BUG_ON(!ref_blkno);
 784         ret = ocfs2_lock_refcount_tree(osb, ref_blkno, 1, &ref_tree, &blk_bh);
 785         if (ret) {
 786                 mlog_errno(ret);
 787                 return ret;
 788         }
 789
 790         rb = (struct ocfs2_refcount_block *)blk_bh->b_data;
 791
 792         /*
 793          * If we are the last user, we need to free the block.
 794          * So lock the allocator ahead.
 795          */
 796         if (le32_to_cpu(rb->rf_count) == 1) {
 797                 blk = le64_to_cpu(rb->rf_blkno);
 798                 bit = le16_to_cpu(rb->rf_suballoc_bit);
 799                 if (rb->rf_suballoc_loc)
 800                         bg_blkno = le64_to_cpu(rb->rf_suballoc_loc);
 801                 else
 802                         bg_blkno = ocfs2_which_suballoc_group(blk, bit);
 803
 804                 alloc_inode = ocfs2_get_system_file_inode(osb,
 805                                         EXTENT_ALLOC_SYSTEM_INODE,
 806                                         le16_to_cpu(rb->rf_suballoc_slot));
 807                 if (!alloc_inode) {
 808                         ret = -ENOMEM;
 809                         mlog_errno(ret);
 810                         goto out;
 811                 }
 812                 mutex_lock(&alloc_inode->i_mutex);
 813
 814                 ret = ocfs2_inode_lock(alloc_inode, &alloc_bh, 1);
 815                 if (ret) {
 816                         mlog_errno(ret);
 817                         goto out_mutex;
 818                 }
 819
 820                 credits += OCFS2_SUBALLOC_FREE;
 821         }
 822
 823         handle = ocfs2_start_trans(osb, credits);
 824         if (IS_ERR(handle)) {
 825                 ret = PTR_ERR(handle);
 826                 mlog_errno(ret);
 827                 goto out_unlock;
 828         }
 829
 830         ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
 831                                       OCFS2_JOURNAL_ACCESS_WRITE);
 832         if (ret) {
 833                 mlog_errno(ret);
 834                 goto out_commit;
 835         }
 836
 837         ret = ocfs2_journal_access_rb(handle, &ref_tree->rf_ci, blk_bh,
 838                                       OCFS2_JOURNAL_ACCESS_WRITE);
 839         if (ret) {
 840                 mlog_errno(ret);
 841                 goto out_commit;
 842         }
 843
 844         spin_lock(&oi->ip_lock);
 845         oi->ip_dyn_features &= ~OCFS2_HAS_REFCOUNT_FL;
 846         di->i_dyn_features = cpu_to_le16(oi->ip_dyn_features);
 847         di->i_refcount_loc = 0;
 848         spin_unlock(&oi->ip_lock);
 849         ocfs2_journal_dirty(handle, di_bh);
 850
 851         le32_add_cpu(&rb->rf_count , -1);
 852         ocfs2_journal_dirty(handle, blk_bh);
 853
 854         if (!rb->rf_count) {
 855                 delete_tree = 1;
 856                 ocfs2_erase_refcount_tree_from_list(osb, ref_tree);
 857                 ret = ocfs2_free_suballoc_bits(handle, alloc_inode,
 858                                                alloc_bh, bit, bg_blkno, 1);
 859                 if (ret)
 860                         mlog_errno(ret);
 861         }
 862
 863 out_commit:
 864         ocfs2_commit_trans(osb, handle);
 865 out_unlock:
 866         if (alloc_inode) {
 867                 ocfs2_inode_unlock(alloc_inode, 1);
 868                 brelse(alloc_bh);
 869         }
 870 out_mutex:
 871         if (alloc_inode) {
 872                 mutex_unlock(&alloc_inode->i_mutex);
 873                 iput(alloc_inode);
 874         }
 875 out:
 876         ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
 877         if (delete_tree)
 878                 ocfs2_refcount_tree_put(ref_tree);
 879         brelse(blk_bh);
 880
 881         return ret;
 882 }
 883
 884 static void ocfs2_find_refcount_rec_in_rl(struct ocfs2_caching_info *ci,
 885                                           struct buffer_head *ref_leaf_bh,
 886                                           u64 cpos, unsigned int len,
 887                                           struct ocfs2_refcount_rec *ret_rec,
 888                                           int *index)
 889 {
 890         int i = 0;
 891         struct ocfs2_refcount_block *rb =
 892                 (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
 893         struct ocfs2_refcount_rec *rec = NULL;
 894
 895         for (; i < le16_to_cpu(rb->rf_records.rl_used); i++) {
 896                 rec = &rb->rf_records.rl_recs[i];
 897
 898                 if (le64_to_cpu(rec->r_cpos) +
 899                     le32_to_cpu(rec->r_clusters) <= cpos)
 900                         continue;
 901                 else if (le64_to_cpu(rec->r_cpos) > cpos)
 902                         break;
 903
 904                 /* ok, cpos fail in this rec. Just return. */
 905                 if (ret_rec)
 906                         *ret_rec = *rec;
 907                 goto out;
 908         }
 909
 910         if (ret_rec) {
 911                 /* We meet with a hole here, so fake the rec. */
 912                 ret_rec->r_cpos = cpu_to_le64(cpos);
 913                 ret_rec->r_refcount = 0;
 914                 if (i < le16_to_cpu(rb->rf_records.rl_used) &&
 915                     le64_to_cpu(rec->r_cpos) < cpos + len)
 916                         ret_rec->r_clusters =
 917                                 cpu_to_le32(le64_to_cpu(rec->r_cpos) - cpos);
 918                 else
 919                         ret_rec->r_clusters = cpu_to_le32(len);
 920         }
 921
 922 out:
 923         *index = i;
 924 }
 925
 926 /*
 927  * Try to remove refcount tree. The mechanism is:
 928  * 1) Check whether i_clusters == 0, if no, exit.
 929  * 2) check whether we have i_xattr_loc in dinode. if yes, exit.
 930  * 3) Check whether we have inline xattr stored outside, if yes, exit.
 931  * 4) Remove the tree.
 932  */
 933 int ocfs2_try_remove_refcount_tree(struct inode *inode,
 934                                    struct buffer_head *di_bh)
 935 {
 936         int ret;
 937         struct ocfs2_inode_info *oi = OCFS2_I(inode);
 938         struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
 939
 940         down_write(&oi->ip_xattr_sem);
 941         down_write(&oi->ip_alloc_sem);
 942
 943         if (oi->ip_clusters)
 944                 goto out;
 945
 946         if ((oi->ip_dyn_features & OCFS2_HAS_XATTR_FL) && di->i_xattr_loc)
 947                 goto out;
 948
 949         if (oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL &&
 950             ocfs2_has_inline_xattr_value_outside(inode, di))
 951                 goto out;
 952
 953         ret = ocfs2_remove_refcount_tree(inode, di_bh);
 954         if (ret)
 955                 mlog_errno(ret);
 956 out:
 957         up_write(&oi->ip_alloc_sem);
 958         up_write(&oi->ip_xattr_sem);
 959         return 0;
 960 }
 961
 962 /*
 963  * Find the end range for a leaf refcount block indicated by
 964  * el->l_recs[index].e_blkno.
 965  */
 966 static int ocfs2_get_refcount_cpos_end(struct ocfs2_caching_info *ci,
 967                                        struct buffer_head *ref_root_bh,
 968                                        struct ocfs2_extent_block *eb,
 969                                        struct ocfs2_extent_list *el,
 970                                        int index,  u32 *cpos_end)
 971 {
 972         int ret, i, subtree_root;
 973         u32 cpos;
 974         u64 blkno;
 975         struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
 976         struct ocfs2_path *left_path = NULL, *right_path = NULL;
 977         struct ocfs2_extent_tree et;
 978         struct ocfs2_extent_list *tmp_el;
 979
 980         if (index < le16_to_cpu(el->l_next_free_rec) - 1) {
 981                 /*
 982                  * We have a extent rec after index, so just use the e_cpos
 983                  * of the next extent rec.
 984                  */
 985                 *cpos_end = le32_to_cpu(el->l_recs[index+1].e_cpos);
 986                 return 0;
 987         }
 988
 989         if (!eb || (eb && !eb->h_next_leaf_blk)) {
 990                 /*
 991                  * We are the last extent rec, so any high cpos should
 992                  * be stored in this leaf refcount block.
 993                  */
 994                 *cpos_end = UINT_MAX;
 995                 return 0;
 996         }
 997
 998         /*
 999          * If the extent block isn't the last one, we have to find
1000          * the subtree root between this extent block and the next
1001          * leaf extent block and get the corresponding e_cpos from
1002          * the subroot. Otherwise we may corrupt the b-tree.
1003          */
1004         ocfs2_init_refcount_extent_tree(&et, ci, ref_root_bh);
1005
1006         left_path = ocfs2_new_path_from_et(&et);
1007         if (!left_path) {
1008                 ret = -ENOMEM;
1009                 mlog_errno(ret);
1010                 goto out;
1011         }
1012
1013         cpos = le32_to_cpu(eb->h_list.l_recs[index].e_cpos);
1014         ret = ocfs2_find_path(ci, left_path, cpos);
1015         if (ret) {
1016                 mlog_errno(ret);
1017                 goto out;
1018         }
1019
1020         right_path = ocfs2_new_path_from_path(left_path);
1021         if (!right_path) {
1022                 ret = -ENOMEM;
1023                 mlog_errno(ret);
1024                 goto out;
1025         }
1026
1027         ret = ocfs2_find_cpos_for_right_leaf(sb, left_path, &cpos);
1028         if (ret) {
1029                 mlog_errno(ret);
1030                 goto out;
1031         }
1032
1033         ret = ocfs2_find_path(ci, right_path, cpos);
1034         if (ret) {
1035                 mlog_errno(ret);
1036                 goto out;
1037         }
1038
1039         subtree_root = ocfs2_find_subtree_root(&et, left_path,
1040                                                right_path);
1041
1042         tmp_el = left_path->p_node[subtree_root].el;
1043         blkno = left_path->p_node[subtree_root+1].bh->b_blocknr;
1044         for (i = 0; i < le16_to_cpu(tmp_el->l_next_free_rec); i++) {
1045                 if (le64_to_cpu(tmp_el->l_recs[i].e_blkno) == blkno) {
1046                         *cpos_end = le32_to_cpu(tmp_el->l_recs[i+1].e_cpos);
1047                         break;
1048                 }
1049         }
1050
1051         BUG_ON(i == le16_to_cpu(tmp_el->l_next_free_rec));
1052
1053 out:
1054         ocfs2_free_path(left_path);
1055         ocfs2_free_path(right_path);
1056         return ret;
1057 }
1058
1059 /*
1060  * Given a cpos and len, try to find the refcount record which contains cpos.
1061  * 1. If cpos can be found in one refcount record, return the record.
1062  * 2. If cpos can't be found, return a fake record which start from cpos
1063  *    and end at a small value between cpos+len and start of the next record.
1064  *    This fake record has r_refcount = 0.
1065  */
1066 static int ocfs2_get_refcount_rec(struct ocfs2_caching_info *ci,
1067                                   struct buffer_head *ref_root_bh,
1068                                   u64 cpos, unsigned int len,
1069                                   struct ocfs2_refcount_rec *ret_rec,
1070                                   int *index,
1071                                   struct buffer_head **ret_bh)
1072 {
1073         int ret = 0, i, found;
1074         u32 low_cpos, uninitialized_var(cpos_end);
1075         struct ocfs2_extent_list *el;
1076         struct ocfs2_extent_rec *rec = NULL;
1077         struct ocfs2_extent_block *eb = NULL;
1078         struct buffer_head *eb_bh = NULL, *ref_leaf_bh = NULL;
1079         struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
1080         struct ocfs2_refcount_block *rb =
1081                         (struct ocfs2_refcount_block *)ref_root_bh->b_data;
1082
1083         if (!(le32_to_cpu(rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL)) {
1084                 ocfs2_find_refcount_rec_in_rl(ci, ref_root_bh, cpos, len,
1085                                               ret_rec, index);
1086                 *ret_bh = ref_root_bh;
1087                 get_bh(ref_root_bh);
1088                 return 0;
1089         }
1090
1091         el = &rb->rf_list;
1092         low_cpos = cpos & OCFS2_32BIT_POS_MASK;
1093
1094         if (el->l_tree_depth) {
1095                 ret = ocfs2_find_leaf(ci, el, low_cpos, &eb_bh);
1096                 if (ret) {
1097                         mlog_errno(ret);
1098                         goto out;
1099                 }
1100
1101                 eb = (struct ocfs2_extent_block *) eb_bh->b_data;
1102                 el = &eb->h_list;
1103
1104                 if (el->l_tree_depth) {
1105                         ocfs2_error(sb,
1106                         "refcount tree %llu has non zero tree "
1107                         "depth in leaf btree tree block %llu\n",
1108                         (unsigned long long)ocfs2_metadata_cache_owner(ci),
1109                         (unsigned long long)eb_bh->b_blocknr);
1110                         ret = -EROFS;
1111                         goto out;
1112                 }
1113         }
1114
1115         found = 0;
1116         for (i = le16_to_cpu(el->l_next_free_rec) - 1; i >= 0; i--) {
1117                 rec = &el->l_recs[i];
1118
1119                 if (le32_to_cpu(rec->e_cpos) <= low_cpos) {
1120                         found = 1;
1121                         break;
1122                 }
1123         }
1124
1125         if (found) {
1126                 ret = ocfs2_get_refcount_cpos_end(ci, ref_root_bh,
1127                                                   eb, el, i, &cpos_end);
1128                 if (ret) {
1129                         mlog_errno(ret);
1130                         goto out;
1131                 }
1132
1133                 if (cpos_end < low_cpos + len)
1134                         len = cpos_end - low_cpos;
1135         }
1136
1137         ret = ocfs2_read_refcount_block(ci, le64_to_cpu(rec->e_blkno),
1138                                         &ref_leaf_bh);
1139         if (ret) {
1140                 mlog_errno(ret);
1141                 goto out;
1142         }
1143
1144         ocfs2_find_refcount_rec_in_rl(ci, ref_leaf_bh, cpos, len,
1145                                       ret_rec, index);
1146         *ret_bh = ref_leaf_bh;
1147 out:
1148         brelse(eb_bh);
1149         return ret;
1150 }
1151
1152 enum ocfs2_ref_rec_contig {
1153         REF_CONTIG_NONE = 0,
1154         REF_CONTIG_LEFT,
1155         REF_CONTIG_RIGHT,
1156         REF_CONTIG_LEFTRIGHT,
1157 };
1158
1159 static enum ocfs2_ref_rec_contig
1160         ocfs2_refcount_rec_adjacent(struct ocfs2_refcount_block *rb,
1161                                     int index)
1162 {
1163         if ((rb->rf_records.rl_recs[index].r_refcount ==
1164             rb->rf_records.rl_recs[index + 1].r_refcount) &&
1165             (le64_to_cpu(rb->rf_records.rl_recs[index].r_cpos) +
1166             le32_to_cpu(rb->rf_records.rl_recs[index].r_clusters) ==
1167             le64_to_cpu(rb->rf_records.rl_recs[index + 1].r_cpos)))
1168                 return REF_CONTIG_RIGHT;
1169
1170         return REF_CONTIG_NONE;
1171 }
1172
1173 static enum ocfs2_ref_rec_contig
1174         ocfs2_refcount_rec_contig(struct ocfs2_refcount_block *rb,
1175                                   int index)
1176 {
1177         enum ocfs2_ref_rec_contig ret = REF_CONTIG_NONE;
1178
1179         if (index < le16_to_cpu(rb->rf_records.rl_used) - 1)
1180                 ret = ocfs2_refcount_rec_adjacent(rb, index);
1181
1182         if (index > 0) {
1183                 enum ocfs2_ref_rec_contig tmp;
1184
1185                 tmp = ocfs2_refcount_rec_adjacent(rb, index - 1);
1186
1187                 if (tmp == REF_CONTIG_RIGHT) {
1188                         if (ret == REF_CONTIG_RIGHT)
1189                                 ret = REF_CONTIG_LEFTRIGHT;
1190                         else
1191                                 ret = REF_CONTIG_LEFT;
1192                 }
1193         }
1194
1195         return ret;
1196 }
1197
1198 static void ocfs2_rotate_refcount_rec_left(struct ocfs2_refcount_block *rb,
1199                                            int index)
1200 {
1201         BUG_ON(rb->rf_records.rl_recs[index].r_refcount !=
1202                rb->rf_records.rl_recs[index+1].r_refcount);
1203
1204         le32_add_cpu(&rb->rf_records.rl_recs[index].r_clusters,
1205                      le32_to_cpu(rb->rf_records.rl_recs[index+1].r_clusters));
1206
1207         if (index < le16_to_cpu(rb->rf_records.rl_used) - 2)
1208                 memmove(&rb->rf_records.rl_recs[index + 1],
1209                         &rb->rf_records.rl_recs[index + 2],
1210                         sizeof(struct ocfs2_refcount_rec) *
1211                         (le16_to_cpu(rb->rf_records.rl_used) - index - 2));
1212
1213         memset(&rb->rf_records.rl_recs[le16_to_cpu(rb->rf_records.rl_used) - 1],
1214                0, sizeof(struct ocfs2_refcount_rec));
1215         le16_add_cpu(&rb->rf_records.rl_used, -1);
1216 }
1217
1218 /*
1219  * Merge the refcount rec if we are contiguous with the adjacent recs.
1220  */
1221 static void ocfs2_refcount_rec_merge(struct ocfs2_refcount_block *rb,
1222                                      int index)
1223 {
1224         enum ocfs2_ref_rec_contig contig =
1225                                 ocfs2_refcount_rec_contig(rb, index);
1226
1227         if (contig == REF_CONTIG_NONE)
1228                 return;
1229
1230         if (contig == REF_CONTIG_LEFT || contig == REF_CONTIG_LEFTRIGHT) {
1231                 BUG_ON(index == 0);
1232                 index--;
1233         }
1234
1235         ocfs2_rotate_refcount_rec_left(rb, index);
1236
1237         if (contig == REF_CONTIG_LEFTRIGHT)
1238                 ocfs2_rotate_refcount_rec_left(rb, index);
1239 }
1240
1241 /*
1242  * Change the refcount indexed by "index" in ref_bh.
1243  * If refcount reaches 0, remove it.
1244  */
1245 static int ocfs2_change_refcount_rec(handle_t *handle,
1246                                      struct ocfs2_caching_info *ci,
1247                                      struct buffer_head *ref_leaf_bh,
1248                                      int index, int merge, int change)
1249 {
1250         int ret;
1251         struct ocfs2_refcount_block *rb =
1252                         (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
1253         struct ocfs2_refcount_list *rl = &rb->rf_records;
1254         struct ocfs2_refcount_rec *rec = &rl->rl_recs[index];
1255
1256         ret = ocfs2_journal_access_rb(handle, ci, ref_leaf_bh,
1257                                       OCFS2_JOURNAL_ACCESS_WRITE);
1258         if (ret) {
1259                 mlog_errno(ret);
1260                 goto out;
1261         }
1262
1263         trace_ocfs2_change_refcount_rec(
1264                 (unsigned long long)ocfs2_metadata_cache_owner(ci),
1265                 index, le32_to_cpu(rec->r_refcount), change);
1266         le32_add_cpu(&rec->r_refcount, change);
1267
1268         if (!rec->r_refcount) {
1269                 if (index != le16_to_cpu(rl->rl_used) - 1) {
1270                         memmove(rec, rec + 1,
1271                                 (le16_to_cpu(rl->rl_used) - index - 1) *
1272                                 sizeof(struct ocfs2_refcount_rec));
1273                         memset(&rl->rl_recs[le16_to_cpu(rl->rl_used) - 1],
1274                                0, sizeof(struct ocfs2_refcount_rec));
1275                 }
1276
1277                 le16_add_cpu(&rl->rl_used, -1);
1278         } else if (merge)
1279                 ocfs2_refcount_rec_merge(rb, index);
1280
1281         ocfs2_journal_dirty(handle, ref_leaf_bh);
1282 out:
1283         return ret;
1284 }
1285
1286 static int ocfs2_expand_inline_ref_root(handle_t *handle,
1287                                         struct ocfs2_caching_info *ci,
1288                                         struct buffer_head *ref_root_bh,
1289                                         struct buffer_head **ref_leaf_bh,
1290                                         struct ocfs2_alloc_context *meta_ac)
1291 {
1292         int ret;
1293         u16 suballoc_bit_start;
1294         u32 num_got;
1295         u64 suballoc_loc, blkno;
1296         struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
1297         struct buffer_head *new_bh = NULL;
1298         struct ocfs2_refcount_block *new_rb;
1299         struct ocfs2_refcount_block *root_rb =
1300                         (struct ocfs2_refcount_block *)ref_root_bh->b_data;
1301
1302         ret = ocfs2_journal_access_rb(handle, ci, ref_root_bh,
1303                                       OCFS2_JOURNAL_ACCESS_WRITE);
1304         if (ret) {
1305                 mlog_errno(ret);
1306                 goto out;
1307         }
1308
1309         ret = ocfs2_claim_metadata(handle, meta_ac, 1, &suballoc_loc,
1310                                    &suballoc_bit_start, &num_got,
1311                                    &blkno);
1312         if (ret) {
1313                 mlog_errno(ret);
1314                 goto out;
1315         }
1316
1317         new_bh = sb_getblk(sb, blkno);
1318         if (new_bh == NULL) {
1319                 ret = -ENOMEM;
1320                 mlog_errno(ret);
1321                 goto out;
1322         }
1323         ocfs2_set_new_buffer_uptodate(ci, new_bh);
1324
1325         ret = ocfs2_journal_access_rb(handle, ci, new_bh,
1326                                       OCFS2_JOURNAL_ACCESS_CREATE);
1327         if (ret) {
1328                 mlog_errno(ret);
1329                 goto out;
1330         }
1331
1332         /*
1333          * Initialize ocfs2_refcount_block.
1334          * It should contain the same information as the old root.
1335          * so just memcpy it and change the corresponding field.
1336          */
1337         memcpy(new_bh->b_data, ref_root_bh->b_data, sb->s_blocksize);
1338
1339         new_rb = (struct ocfs2_refcount_block *)new_bh->b_data;
1340         new_rb->rf_suballoc_slot = cpu_to_le16(meta_ac->ac_alloc_slot);
1341         new_rb->rf_suballoc_loc = cpu_to_le64(suballoc_loc);
1342         new_rb->rf_suballoc_bit = cpu_to_le16(suballoc_bit_start);
1343         new_rb->rf_blkno = cpu_to_le64(blkno);
1344         new_rb->rf_cpos = cpu_to_le32(0);
1345         new_rb->rf_parent = cpu_to_le64(ref_root_bh->b_blocknr);
1346         new_rb->rf_flags = cpu_to_le32(OCFS2_REFCOUNT_LEAF_FL);
1347         ocfs2_journal_dirty(handle, new_bh);
1348
1349         /* Now change the root. */
1350         memset(&root_rb->rf_list, 0, sb->s_blocksize -
1351                offsetof(struct ocfs2_refcount_block, rf_list));
1352         root_rb->rf_list.l_count = cpu_to_le16(ocfs2_extent_recs_per_rb(sb));
1353         root_rb->rf_clusters = cpu_to_le32(1);
1354         root_rb->rf_list.l_next_free_rec = cpu_to_le16(1);
1355         root_rb->rf_list.l_recs[0].e_blkno = cpu_to_le64(blkno);
1356         root_rb->rf_list.l_recs[0].e_leaf_clusters = cpu_to_le16(1);
1357         root_rb->rf_flags = cpu_to_le32(OCFS2_REFCOUNT_TREE_FL);
1358
1359         ocfs2_journal_dirty(handle, ref_root_bh);
1360
1361         trace_ocfs2_expand_inline_ref_root((unsigned long long)blkno,
1362                 le16_to_cpu(new_rb->rf_records.rl_used));
1363
1364         *ref_leaf_bh = new_bh;
1365         new_bh = NULL;
1366 out:
1367         brelse(new_bh);
1368         return ret;
1369 }
1370
1371 static int ocfs2_refcount_rec_no_intersect(struct ocfs2_refcount_rec *prev,
1372                                            struct ocfs2_refcount_rec *next)
1373 {
1374         if (ocfs2_get_ref_rec_low_cpos(prev) + le32_to_cpu(prev->r_clusters) <=
1375                 ocfs2_get_ref_rec_low_cpos(next))
1376                 return 1;
1377
1378         return 0;
1379 }
1380
1381 static int cmp_refcount_rec_by_low_cpos(const void *a, const void *b)
1382 {
1383         const struct ocfs2_refcount_rec *l = a, *r = b;
1384         u32 l_cpos = ocfs2_get_ref_rec_low_cpos(l);
1385         u32 r_cpos = ocfs2_get_ref_rec_low_cpos(r);
1386
1387         if (l_cpos > r_cpos)
1388                 return 1;
1389         if (l_cpos < r_cpos)
1390                 return -1;
1391         return 0;
1392 }
1393
1394 static int cmp_refcount_rec_by_cpos(const void *a, const void *b)
1395 {
1396         const struct ocfs2_refcount_rec *l = a, *r = b;
1397         u64 l_cpos = le64_to_cpu(l->r_cpos);
1398         u64 r_cpos = le64_to_cpu(r->r_cpos);
1399
1400         if (l_cpos > r_cpos)
1401                 return 1;
1402         if (l_cpos < r_cpos)
1403                 return -1;
1404         return 0;
1405 }
1406
1407 static void swap_refcount_rec(void *a, void *b, int size)
1408 {
1409         struct ocfs2_refcount_rec *l = a, *r = b, tmp;
1410
1411         tmp = *l;
1412         *l = *r;
1413         *r = tmp;
1414 }
1415
1416 /*
1417  * The refcount cpos are ordered by their 64bit cpos,
1418  * But we will use the low 32 bit to be the e_cpos in the b-tree.
1419  * So we need to make sure that this pos isn't intersected with others.
1420  *
1421  * Note: The refcount block is already sorted by their low 32 bit cpos,
1422  *       So just try the middle pos first, and we will exit when we find
1423  *       the good position.
1424  */
1425 static int ocfs2_find_refcount_split_pos(struct ocfs2_refcount_list *rl,
1426                                          u32 *split_pos, int *split_index)
1427 {
1428         int num_used = le16_to_cpu(rl->rl_used);
1429         int delta, middle = num_used / 2;
1430
1431         for (delta = 0; delta < middle; delta++) {
1432                 /* Let's check delta earlier than middle */
1433                 if (ocfs2_refcount_rec_no_intersect(
1434                                         &rl->rl_recs[middle - delta - 1],
1435                                         &rl->rl_recs[middle - delta])) {
1436                         *split_index = middle - delta;
1437                         break;
1438                 }
1439
1440                 /* For even counts, don't walk off the end */
1441                 if ((middle + delta + 1) == num_used)
1442                         continue;
1443
1444                 /* Now try delta past middle */
1445                 if (ocfs2_refcount_rec_no_intersect(
1446                                         &rl->rl_recs[middle + delta],
1447                                         &rl->rl_recs[middle + delta + 1])) {
1448                         *split_index = middle + delta + 1;
1449                         break;
1450                 }
1451         }
1452
1453         if (delta >= middle)
1454                 return -ENOSPC;
1455
1456         *split_pos = ocfs2_get_ref_rec_low_cpos(&rl->rl_recs[*split_index]);
1457         return 0;
1458 }
1459
1460 static int ocfs2_divide_leaf_refcount_block(struct buffer_head *ref_leaf_bh,
1461                                             struct buffer_head *new_bh,
1462                                             u32 *split_cpos)
1463 {
1464         int split_index = 0, num_moved, ret;
1465         u32 cpos = 0;
1466         struct ocfs2_refcount_block *rb =
1467                         (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
1468         struct ocfs2_refcount_list *rl = &rb->rf_records;
1469         struct ocfs2_refcount_block *new_rb =
1470                         (struct ocfs2_refcount_block *)new_bh->b_data;
1471         struct ocfs2_refcount_list *new_rl = &new_rb->rf_records;
1472
1473         trace_ocfs2_divide_leaf_refcount_block(
1474                 (unsigned long long)ref_leaf_bh->b_blocknr,
1475                 le16_to_cpu(rl->rl_count), le16_to_cpu(rl->rl_used));
1476
1477         /*
1478          * XXX: Improvement later.
1479          * If we know all the high 32 bit cpos is the same, no need to sort.
1480          *
1481          * In order to make the whole process safe, we do:
1482          * 1. sort the entries by their low 32 bit cpos first so that we can
1483          *    find the split cpos easily.
1484          * 2. call ocfs2_insert_extent to insert the new refcount block.
1485          * 3. move the refcount rec to the new block.
1486          * 4. sort the entries by their 64 bit cpos.
1487          * 5. dirty the new_rb and rb.
1488          */
1489         sort(&rl->rl_recs, le16_to_cpu(rl->rl_used),
1490              sizeof(struct ocfs2_refcount_rec),
1491              cmp_refcount_rec_by_low_cpos, swap_refcount_rec);
1492
1493         ret = ocfs2_find_refcount_split_pos(rl, &cpos, &split_index);
1494         if (ret) {
1495                 mlog_errno(ret);
1496                 return ret;
1497         }
1498
1499         new_rb->rf_cpos = cpu_to_le32(cpos);
1500
1501         /* move refcount records starting from split_index to the new block. */
1502         num_moved = le16_to_cpu(rl->rl_used) - split_index;
1503         memcpy(new_rl->rl_recs, &rl->rl_recs[split_index],
1504                num_moved * sizeof(struct ocfs2_refcount_rec));
1505
1506         /*ok, remove the entries we just moved over to the other block. */
1507         memset(&rl->rl_recs[split_index], 0,
1508                num_moved * sizeof(struct ocfs2_refcount_rec));
1509
1510         /* change old and new rl_used accordingly. */
1511         le16_add_cpu(&rl->rl_used, -num_moved);
1512         new_rl->rl_used = cpu_to_le16(num_moved);
1513
1514         sort(&rl->rl_recs, le16_to_cpu(rl->rl_used),
1515              sizeof(struct ocfs2_refcount_rec),
1516              cmp_refcount_rec_by_cpos, swap_refcount_rec);
1517
1518         sort(&new_rl->rl_recs, le16_to_cpu(new_rl->rl_used),
1519              sizeof(struct ocfs2_refcount_rec),
1520              cmp_refcount_rec_by_cpos, swap_refcount_rec);
1521
1522         *split_cpos = cpos;
1523         return 0;
1524 }
1525
1526 static int ocfs2_new_leaf_refcount_block(handle_t *handle,
1527                                          struct ocfs2_caching_info *ci,
1528                                          struct buffer_head *ref_root_bh,
1529                                          struct buffer_head *ref_leaf_bh,
1530                                          struct ocfs2_alloc_context *meta_ac)
1531 {
1532         int ret;
1533         u16 suballoc_bit_start;
1534         u32 num_got, new_cpos;
1535         u64 suballoc_loc, blkno;
1536         struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
1537         struct ocfs2_refcount_block *root_rb =
1538                         (struct ocfs2_refcount_block *)ref_root_bh->b_data;
1539         struct buffer_head *new_bh = NULL;
1540         struct ocfs2_refcount_block *new_rb;
1541         struct ocfs2_extent_tree ref_et;
1542
1543         BUG_ON(!(le32_to_cpu(root_rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL));
1544
1545         ret = ocfs2_journal_access_rb(handle, ci, ref_root_bh,
1546                                       OCFS2_JOURNAL_ACCESS_WRITE);
1547         if (ret) {
1548                 mlog_errno(ret);
1549                 goto out;
1550         }
1551
1552         ret = ocfs2_journal_access_rb(handle, ci, ref_leaf_bh,
1553                                       OCFS2_JOURNAL_ACCESS_WRITE);
1554         if (ret) {
1555                 mlog_errno(ret);
1556                 goto out;
1557         }
1558
1559         ret = ocfs2_claim_metadata(handle, meta_ac, 1, &suballoc_loc,
1560                                    &suballoc_bit_start, &num_got,
1561                                    &blkno);
1562         if (ret) {
1563                 mlog_errno(ret);
1564                 goto out;
1565         }
1566
1567         new_bh = sb_getblk(sb, blkno);
1568         if (new_bh == NULL) {
1569                 ret = -ENOMEM;
1570                 mlog_errno(ret);
1571                 goto out;
1572         }
1573         ocfs2_set_new_buffer_uptodate(ci, new_bh);
1574
1575         ret = ocfs2_journal_access_rb(handle, ci, new_bh,
1576                                       OCFS2_JOURNAL_ACCESS_CREATE);
1577         if (ret) {
1578                 mlog_errno(ret);
1579                 goto out;
1580         }
1581
1582         /* Initialize ocfs2_refcount_block. */
1583         new_rb = (struct ocfs2_refcount_block *)new_bh->b_data;
1584         memset(new_rb, 0, sb->s_blocksize);
1585         strcpy((void *)new_rb, OCFS2_REFCOUNT_BLOCK_SIGNATURE);
1586         new_rb->rf_suballoc_slot = cpu_to_le16(meta_ac->ac_alloc_slot);
1587         new_rb->rf_suballoc_loc = cpu_to_le64(suballoc_loc);
1588         new_rb->rf_suballoc_bit = cpu_to_le16(suballoc_bit_start);
1589         new_rb->rf_fs_generation = cpu_to_le32(OCFS2_SB(sb)->fs_generation);
1590         new_rb->rf_blkno = cpu_to_le64(blkno);
1591         new_rb->rf_parent = cpu_to_le64(ref_root_bh->b_blocknr);
1592         new_rb->rf_flags = cpu_to_le32(OCFS2_REFCOUNT_LEAF_FL);
1593         new_rb->rf_records.rl_count =
1594                                 cpu_to_le16(ocfs2_refcount_recs_per_rb(sb));
1595         new_rb->rf_generation = root_rb->rf_generation;
1596
1597         ret = ocfs2_divide_leaf_refcount_block(ref_leaf_bh, new_bh, &new_cpos);
1598         if (ret) {
1599                 mlog_errno(ret);
1600                 goto out;
1601         }
1602
1603         ocfs2_journal_dirty(handle, ref_leaf_bh);
1604         ocfs2_journal_dirty(handle, new_bh);
1605
1606         ocfs2_init_refcount_extent_tree(&ref_et, ci, ref_root_bh);
1607
1608         trace_ocfs2_new_leaf_refcount_block(
1609                         (unsigned long long)new_bh->b_blocknr, new_cpos);
1610
1611         /* Insert the new leaf block with the specific offset cpos. */
1612         ret = ocfs2_insert_extent(handle, &ref_et, new_cpos, new_bh->b_blocknr,
1613                                   1, 0, meta_ac);
1614         if (ret)
1615                 mlog_errno(ret);
1616
1617 out:
1618         brelse(new_bh);
1619         return ret;
1620 }
1621
1622 static int ocfs2_expand_refcount_tree(handle_t *handle,
1623                                       struct ocfs2_caching_info *ci,
1624                                       struct buffer_head *ref_root_bh,
1625                                       struct buffer_head *ref_leaf_bh,
1626                                       struct ocfs2_alloc_context *meta_ac)
1627 {
1628         int ret;
1629         struct buffer_head *expand_bh = NULL;
1630
1631         if (ref_root_bh == ref_leaf_bh) {
1632                 /*
1633                  * the old root bh hasn't been expanded to a b-tree,
1634                  * so expand it first.
1635                  */
1636                 ret = ocfs2_expand_inline_ref_root(handle, ci, ref_root_bh,
1637                                                    &expand_bh, meta_ac);
1638                 if (ret) {
1639                         mlog_errno(ret);
1640                         goto out;
1641                 }
1642         } else {
1643                 expand_bh = ref_leaf_bh;
1644                 get_bh(expand_bh);
1645         }
1646
1647
1648         /* Now add a new refcount block into the tree.*/
1649         ret = ocfs2_new_leaf_refcount_block(handle, ci, ref_root_bh,
1650                                             expand_bh, meta_ac);
1651         if (ret)
1652                 mlog_errno(ret);
1653 out:
1654         brelse(expand_bh);
1655         return ret;
1656 }
1657
1658 /*
1659  * Adjust the extent rec in b-tree representing ref_leaf_bh.
1660  *
1661  * Only called when we have inserted a new refcount rec at index 0
1662  * which means ocfs2_extent_rec.e_cpos may need some change.
1663  */
1664 static int ocfs2_adjust_refcount_rec(handle_t *handle,
1665                                      struct ocfs2_caching_info *ci,
1666                                      struct buffer_head *ref_root_bh,
1667                                      struct buffer_head *ref_leaf_bh,
1668                                      struct ocfs2_refcount_rec *rec)
1669 {
1670         int ret = 0, i;
1671         u32 new_cpos, old_cpos;
1672         struct ocfs2_path *path = NULL;
1673         struct ocfs2_extent_tree et;
1674         struct ocfs2_refcount_block *rb =
1675                 (struct ocfs2_refcount_block *)ref_root_bh->b_data;
1676         struct ocfs2_extent_list *el;
1677
1678         if (!(le32_to_cpu(rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL))
1679                 goto out;
1680
1681         rb = (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
1682         old_cpos = le32_to_cpu(rb->rf_cpos);
1683         new_cpos = le64_to_cpu(rec->r_cpos) & OCFS2_32BIT_POS_MASK;
1684         if (old_cpos <= new_cpos)
1685                 goto out;
1686
1687         ocfs2_init_refcount_extent_tree(&et, ci, ref_root_bh);
1688
1689         path = ocfs2_new_path_from_et(&et);
1690         if (!path) {
1691                 ret = -ENOMEM;
1692                 mlog_errno(ret);
1693                 goto out;
1694         }
1695
1696         ret = ocfs2_find_path(ci, path, old_cpos);
1697         if (ret) {
1698                 mlog_errno(ret);
1699                 goto out;
1700         }
1701
1702         /*
1703          * 2 more credits, one for the leaf refcount block, one for
1704          * the extent block contains the extent rec.
1705          */
1706         ret = ocfs2_extend_trans(handle, 2);
1707         if (ret < 0) {
1708                 mlog_errno(ret);
1709                 goto out;
1710         }
1711
1712         ret = ocfs2_journal_access_rb(handle, ci, ref_leaf_bh,
1713                                       OCFS2_JOURNAL_ACCESS_WRITE);
1714         if (ret < 0) {
1715                 mlog_errno(ret);
1716                 goto out;
1717         }
1718
1719         ret = ocfs2_journal_access_eb(handle, ci, path_leaf_bh(path),
1720                                       OCFS2_JOURNAL_ACCESS_WRITE);
1721         if (ret < 0) {
1722                 mlog_errno(ret);
1723                 goto out;
1724         }
1725
1726         /* change the leaf extent block first. */
1727         el = path_leaf_el(path);
1728
1729         for (i = 0; i < le16_to_cpu(el->l_next_free_rec); i++)
1730                 if (le32_to_cpu(el->l_recs[i].e_cpos) == old_cpos)
1731                         break;
1732
1733         BUG_ON(i == le16_to_cpu(el->l_next_free_rec));
1734
1735         el->l_recs[i].e_cpos = cpu_to_le32(new_cpos);
1736
1737         /* change the r_cpos in the leaf block. */
1738         rb->rf_cpos = cpu_to_le32(new_cpos);
1739
1740         ocfs2_journal_dirty(handle, path_leaf_bh(path));
1741         ocfs2_journal_dirty(handle, ref_leaf_bh);
1742
1743 out:
1744         ocfs2_free_path(path);
1745         return ret;
1746 }
1747
1748 static int ocfs2_insert_refcount_rec(handle_t *handle,
1749                                      struct ocfs2_caching_info *ci,
1750                                      struct buffer_head *ref_root_bh,
1751                                      struct buffer_head *ref_leaf_bh,
1752                                      struct ocfs2_refcount_rec *rec,
1753                                      int index, int merge,
1754                                      struct ocfs2_alloc_context *meta_ac)
1755 {
1756         int ret;
1757         struct ocfs2_refcount_block *rb =
1758                         (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
1759         struct ocfs2_refcount_list *rf_list = &rb->rf_records;
1760         struct buffer_head *new_bh = NULL;
1761
1762         BUG_ON(le32_to_cpu(rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL);
1763
1764         if (rf_list->rl_used == rf_list->rl_count) {
1765                 u64 cpos = le64_to_cpu(rec->r_cpos);
1766                 u32 len = le32_to_cpu(rec->r_clusters);
1767
1768                 ret = ocfs2_expand_refcount_tree(handle, ci, ref_root_bh,
1769                                                  ref_leaf_bh, meta_ac);
1770                 if (ret) {
1771                         mlog_errno(ret);
1772                         goto out;
1773                 }
1774
1775                 ret = ocfs2_get_refcount_rec(ci, ref_root_bh,
1776                                              cpos, len, NULL, &index,
1777                                              &new_bh);
1778                 if (ret) {
1779                         mlog_errno(ret);
1780                         goto out;
1781                 }
1782
1783                 ref_leaf_bh = new_bh;
1784                 rb = (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
1785                 rf_list = &rb->rf_records;
1786         }
1787
1788         ret = ocfs2_journal_access_rb(handle, ci, ref_leaf_bh,
1789                                       OCFS2_JOURNAL_ACCESS_WRITE);
1790         if (ret) {
1791                 mlog_errno(ret);
1792                 goto out;
1793         }
1794
1795         if (index < le16_to_cpu(rf_list->rl_used))
1796                 memmove(&rf_list->rl_recs[index + 1],
1797                         &rf_list->rl_recs[index],
1798                         (le16_to_cpu(rf_list->rl_used) - index) *
1799                          sizeof(struct ocfs2_refcount_rec));
1800
1801         trace_ocfs2_insert_refcount_rec(
1802                 (unsigned long long)ref_leaf_bh->b_blocknr, index,
1803                 (unsigned long long)le64_to_cpu(rec->r_cpos),
1804                 le32_to_cpu(rec->r_clusters), le32_to_cpu(rec->r_refcount));
1805
1806         rf_list->rl_recs[index] = *rec;
1807
1808         le16_add_cpu(&rf_list->rl_used, 1);
1809
1810         if (merge)
1811                 ocfs2_refcount_rec_merge(rb, index);
1812
1813         ocfs2_journal_dirty(handle, ref_leaf_bh);
1814
1815         if (index == 0) {
1816                 ret = ocfs2_adjust_refcount_rec(handle, ci,
1817                                                 ref_root_bh,
1818                                                 ref_leaf_bh, rec);
1819                 if (ret)
1820                         mlog_errno(ret);
1821         }
1822 out:
1823         brelse(new_bh);
1824         return ret;
1825 }
1826
1827 /*
1828  * Split the refcount_rec indexed by "index" in ref_leaf_bh.
1829  * This is much simple than our b-tree code.
1830  * split_rec is the new refcount rec we want to insert.
1831  * If split_rec->r_refcount > 0, we are changing the refcount(in case we
1832  * increase refcount or decrease a refcount to non-zero).
1833  * If split_rec->r_refcount == 0, we are punching a hole in current refcount
1834  * rec( in case we decrease a refcount to zero).
1835  */
1836 static int ocfs2_split_refcount_rec(handle_t *handle,
1837                                     struct ocfs2_caching_info *ci,
1838                                     struct buffer_head *ref_root_bh,
1839                                     struct buffer_head *ref_leaf_bh,
1840                                     struct ocfs2_refcount_rec *split_rec,
1841                                     int index, int merge,
1842                                     struct ocfs2_alloc_context *meta_ac,
1843                                     struct ocfs2_cached_dealloc_ctxt *dealloc)
1844 {
1845         int ret, recs_need;
1846         u32 len;
1847         struct ocfs2_refcount_block *rb =
1848                         (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
1849         struct ocfs2_refcount_list *rf_list = &rb->rf_records;
1850         struct ocfs2_refcount_rec *orig_rec = &rf_list->rl_recs[index];
1851         struct ocfs2_refcount_rec *tail_rec = NULL;
1852         struct buffer_head *new_bh = NULL;
1853
1854         BUG_ON(le32_to_cpu(rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL);
1855
1856         trace_ocfs2_split_refcount_rec(le64_to_cpu(orig_rec->r_cpos),
1857                 le32_to_cpu(orig_rec->r_clusters),
1858                 le32_to_cpu(orig_rec->r_refcount),
1859                 le64_to_cpu(split_rec->r_cpos),
1860                 le32_to_cpu(split_rec->r_clusters),
1861                 le32_to_cpu(split_rec->r_refcount));
1862
1863         /*
1864          * If we just need to split the header or tail clusters,
1865          * no more recs are needed, just split is OK.
1866          * Otherwise we at least need one new recs.
1867          */
1868         if (!split_rec->r_refcount &&
1869             (split_rec->r_cpos == orig_rec->r_cpos ||
1870              le64_to_cpu(split_rec->r_cpos) +
1871              le32_to_cpu(split_rec->r_clusters) ==
1872              le64_to_cpu(orig_rec->r_cpos) + le32_to_cpu(orig_rec->r_clusters)))
1873                 recs_need = 0;
1874         else
1875                 recs_need = 1;
1876
1877         /*
1878          * We need one more rec if we split in the middle and the new rec have
1879          * some refcount in it.
1880          */
1881         if (split_rec->r_refcount &&
1882             (split_rec->r_cpos != orig_rec->r_cpos &&
1883              le64_to_cpu(split_rec->r_cpos) +
1884              le32_to_cpu(split_rec->r_clusters) !=
1885              le64_to_cpu(orig_rec->r_cpos) + le32_to_cpu(orig_rec->r_clusters)))
1886                 recs_need++;
1887
1888         /* If the leaf block don't have enough record, expand it. */
1889         if (le16_to_cpu(rf_list->rl_used) + recs_need >
1890                                          le16_to_cpu(rf_list->rl_count)) {
1891                 struct ocfs2_refcount_rec tmp_rec;
1892                 u64 cpos = le64_to_cpu(orig_rec->r_cpos);
1893                 len = le32_to_cpu(orig_rec->r_clusters);
1894                 ret = ocfs2_expand_refcount_tree(handle, ci, ref_root_bh,
1895                                                  ref_leaf_bh, meta_ac);
1896                 if (ret) {
1897                         mlog_errno(ret);
1898                         goto out;
1899                 }
1900
1901                 /*
1902                  * We have to re-get it since now cpos may be moved to
1903                  * another leaf block.
1904                  */
1905                 ret = ocfs2_get_refcount_rec(ci, ref_root_bh,
1906                                              cpos, len, &tmp_rec, &index,
1907                                              &new_bh);
1908                 if (ret) {
1909                         mlog_errno(ret);
1910                         goto out;
1911                 }
1912
1913                 ref_leaf_bh = new_bh;
1914                 rb = (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
1915                 rf_list = &rb->rf_records;
1916                 orig_rec = &rf_list->rl_recs[index];
1917         }
1918
1919         ret = ocfs2_journal_access_rb(handle, ci, ref_leaf_bh,
1920                                       OCFS2_JOURNAL_ACCESS_WRITE);
1921         if (ret) {
1922                 mlog_errno(ret);
1923                 goto out;
1924         }
1925
1926         /*
1927          * We have calculated out how many new records we need and store
1928          * in recs_need, so spare enough space first by moving the records
1929          * after "index" to the end.
1930          */
1931         if (index != le16_to_cpu(rf_list->rl_used) - 1)
1932                 memmove(&rf_list->rl_recs[index + 1 + recs_need],
1933                         &rf_list->rl_recs[index + 1],
1934                         (le16_to_cpu(rf_list->rl_used) - index - 1) *
1935                          sizeof(struct ocfs2_refcount_rec));
1936
1937         len = (le64_to_cpu(orig_rec->r_cpos) +
1938               le32_to_cpu(orig_rec->r_clusters)) -
1939               (le64_to_cpu(split_rec->r_cpos) +
1940               le32_to_cpu(split_rec->r_clusters));
1941
1942         /*
1943          * If we have "len", the we will split in the tail and move it
1944          * to the end of the space we have just spared.
1945          */
1946         if (len) {
1947                 tail_rec = &rf_list->rl_recs[index + recs_need];
1948
1949                 memcpy(tail_rec, orig_rec, sizeof(struct ocfs2_refcount_rec));
1950                 le64_add_cpu(&tail_rec->r_cpos,
1951                              le32_to_cpu(tail_rec->r_clusters) - len);
1952                 tail_rec->r_clusters = cpu_to_le32(len);
1953         }
1954
1955         /*
1956          * If the split pos isn't the same as the original one, we need to
1957          * split in the head.
1958          *
1959          * Note: We have the chance that split_rec.r_refcount = 0,
1960          * recs_need = 0 and len > 0, which means we just cut the head from
1961          * the orig_rec and in that case we have done some modification in
1962          * orig_rec above, so the check for r_cpos is faked.
1963          */
1964         if (split_rec->r_cpos != orig_rec->r_cpos && tail_rec != orig_rec) {
1965                 len = le64_to_cpu(split_rec->r_cpos) -
1966                       le64_to_cpu(orig_rec->r_cpos);
1967                 orig_rec->r_clusters = cpu_to_le32(len);
1968                 index++;
1969         }
1970
1971         le16_add_cpu(&rf_list->rl_used, recs_need);
1972
1973         if (split_rec->r_refcount) {
1974                 rf_list->rl_recs[index] = *split_rec;
1975                 trace_ocfs2_split_refcount_rec_insert(
1976                         (unsigned long long)ref_leaf_bh->b_blocknr, index,
1977                         (unsigned long long)le64_to_cpu(split_rec->r_cpos),
1978                         le32_to_cpu(split_rec->r_clusters),
1979                         le32_to_cpu(split_rec->r_refcount));
1980
1981                 if (merge)
1982                         ocfs2_refcount_rec_merge(rb, index);
1983         }
1984
1985         ocfs2_journal_dirty(handle, ref_leaf_bh);
1986
1987 out:
1988         brelse(new_bh);
1989         return ret;
1990 }
1991
1992 static int __ocfs2_increase_refcount(handle_t *handle,
1993                                      struct ocfs2_caching_info *ci,
1994                                      struct buffer_head *ref_root_bh,
1995                                      u64 cpos, u32 len, int merge,
1996                                      struct ocfs2_alloc_context *meta_ac,
1997                                      struct ocfs2_cached_dealloc_ctxt *dealloc)
1998 {
1999         int ret = 0, index;
2000         struct buffer_head *ref_leaf_bh = NULL;
2001         struct ocfs2_refcount_rec rec;
2002         unsigned int set_len = 0;
2003
2004         trace_ocfs2_increase_refcount_begin(
2005              (unsigned long long)ocfs2_metadata_cache_owner(ci),
2006              (unsigned long long)cpos, len);
2007
2008         while (len) {
2009                 ret = ocfs2_get_refcount_rec(ci, ref_root_bh,
2010                                              cpos, len, &rec, &index,
2011                                              &ref_leaf_bh);
2012                 if (ret) {
2013                         mlog_errno(ret);
2014                         goto out;
2015                 }
2016
2017                 set_len = le32_to_cpu(rec.r_clusters);
2018
2019                 /*
2020                  * Here we may meet with 3 situations:
2021                  *
2022                  * 1. If we find an already existing record, and the length
2023                  *    is the same, cool, we just need to increase the r_refcount
2024                  *    and it is OK.
2025                  * 2. If we find a hole, just insert it with r_refcount = 1.
2026                  * 3. If we are in the middle of one extent record, split
2027                  *    it.
2028                  */
2029                 if (rec.r_refcount && le64_to_cpu(rec.r_cpos) == cpos &&
2030                     set_len <= len) {
2031                         trace_ocfs2_increase_refcount_change(
2032                                 (unsigned long long)cpos, set_len,
2033                                 le32_to_cpu(rec.r_refcount));
2034                         ret = ocfs2_change_refcount_rec(handle, ci,
2035                                                         ref_leaf_bh, index,
2036                                                         merge, 1);
2037                         if (ret) {
2038                                 mlog_errno(ret);
2039                                 goto out;
2040                         }
2041                 } else if (!rec.r_refcount) {
2042                         rec.r_refcount = cpu_to_le32(1);
2043
2044                         trace_ocfs2_increase_refcount_insert(
2045                              (unsigned long long)le64_to_cpu(rec.r_cpos),
2046                              set_len);
2047                         ret = ocfs2_insert_refcount_rec(handle, ci, ref_root_bh,
2048                                                         ref_leaf_bh,
2049                                                         &rec, index,
2050                                                         merge, meta_ac);
2051                         if (ret) {
2052                                 mlog_errno(ret);
2053                                 goto out;
2054                         }
2055                 } else  {
2056                         set_len = min((u64)(cpos + len),
2057                                       le64_to_cpu(rec.r_cpos) + set_len) - cpos;
2058                         rec.r_cpos = cpu_to_le64(cpos);
2059                         rec.r_clusters = cpu_to_le32(set_len);
2060                         le32_add_cpu(&rec.r_refcount, 1);
2061
2062                         trace_ocfs2_increase_refcount_split(
2063                              (unsigned long long)le64_to_cpu(rec.r_cpos),
2064                              set_len, le32_to_cpu(rec.r_refcount));
2065                         ret = ocfs2_split_refcount_rec(handle, ci,
2066                                                        ref_root_bh, ref_leaf_bh,
2067                                                        &rec, index, merge,
2068                                                        meta_ac, dealloc);
2069                         if (ret) {
2070                                 mlog_errno(ret);
2071                                 goto out;
2072                         }
2073                 }
2074
2075                 cpos += set_len;
2076                 len -= set_len;
2077                 brelse(ref_leaf_bh);
2078                 ref_leaf_bh = NULL;
2079         }
2080
2081 out:
2082         brelse(ref_leaf_bh);
2083         return ret;
2084 }
2085
2086 static int ocfs2_remove_refcount_extent(handle_t *handle,
2087                                 struct ocfs2_caching_info *ci,
2088                                 struct buffer_head *ref_root_bh,
2089                                 struct buffer_head *ref_leaf_bh,
2090                                 struct ocfs2_alloc_context *meta_ac,
2091                                 struct ocfs2_cached_dealloc_ctxt *dealloc)
2092 {
2093         int ret;
2094         struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
2095         struct ocfs2_refcount_block *rb =
2096                         (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
2097         struct ocfs2_extent_tree et;
2098
2099         BUG_ON(rb->rf_records.rl_used);
2100
2101         trace_ocfs2_remove_refcount_extent(
2102                 (unsigned long long)ocfs2_metadata_cache_owner(ci),
2103                 (unsigned long long)ref_leaf_bh->b_blocknr,
2104                 le32_to_cpu(rb->rf_cpos));
2105
2106         ocfs2_init_refcount_extent_tree(&et, ci, ref_root_bh);
2107         ret = ocfs2_remove_extent(handle, &et, le32_to_cpu(rb->rf_cpos),
2108                                   1, meta_ac, dealloc);
2109         if (ret) {
2110                 mlog_errno(ret);
2111                 goto out;
2112         }
2113
2114         ocfs2_remove_from_cache(ci, ref_leaf_bh);
2115
2116         /*
2117          * add the freed block to the dealloc so that it will be freed
2118          * when we run dealloc.
2119          */
2120         ret = ocfs2_cache_block_dealloc(dealloc, EXTENT_ALLOC_SYSTEM_INODE,
2121                                         le16_to_cpu(rb->rf_suballoc_slot),
2122                                         le64_to_cpu(rb->rf_suballoc_loc),
2123                                         le64_to_cpu(rb->rf_blkno),
2124                                         le16_to_cpu(rb->rf_suballoc_bit));
2125         if (ret) {
2126                 mlog_errno(ret);
2127                 goto out;
2128         }
2129
2130         ret = ocfs2_journal_access_rb(handle, ci, ref_root_bh,
2131                                       OCFS2_JOURNAL_ACCESS_WRITE);
2132         if (ret) {
2133                 mlog_errno(ret);
2134                 goto out;
2135         }
2136
2137         rb = (struct ocfs2_refcount_block *)ref_root_bh->b_data;
2138
2139         le32_add_cpu(&rb->rf_clusters, -1);
2140
2141         /*
2142          * check whether we need to restore the root refcount block if
2143          * there is no leaf extent block at atll.
2144          */
2145         if (!rb->rf_list.l_next_free_rec) {
2146                 BUG_ON(rb->rf_clusters);
2147
2148                 trace_ocfs2_restore_refcount_block(
2149                      (unsigned long long)ref_root_bh->b_blocknr);
2150
2151                 rb->rf_flags = 0;
2152                 rb->rf_parent = 0;
2153                 rb->rf_cpos = 0;
2154                 memset(&rb->rf_records, 0, sb->s_blocksize -
2155                        offsetof(struct ocfs2_refcount_block, rf_records));
2156                 rb->rf_records.rl_count =
2157                                 cpu_to_le16(ocfs2_refcount_recs_per_rb(sb));
2158         }
2159
2160         ocfs2_journal_dirty(handle, ref_root_bh);
2161
2162 out:
2163         return ret;
2164 }
2165
2166 int ocfs2_increase_refcount(handle_t *handle,
2167                             struct ocfs2_caching_info *ci,
2168                             struct buffer_head *ref_root_bh,
2169                             u64 cpos, u32 len,
2170                             struct ocfs2_alloc_context *meta_ac,
2171                             struct ocfs2_cached_dealloc_ctxt *dealloc)
2172 {
2173         return __ocfs2_increase_refcount(handle, ci, ref_root_bh,
2174                                          cpos, len, 1,
2175                                          meta_ac, dealloc);
2176 }
2177
2178 static int ocfs2_decrease_refcount_rec(handle_t *handle,
2179                                 struct ocfs2_caching_info *ci,
2180                                 struct buffer_head *ref_root_bh,
2181                                 struct buffer_head *ref_leaf_bh,
2182                                 int index, u64 cpos, unsigned int len,
2183                                 struct ocfs2_alloc_context *meta_ac,
2184                                 struct ocfs2_cached_dealloc_ctxt *dealloc)
2185 {
2186         int ret;
2187         struct ocfs2_refcount_block *rb =
2188                         (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
2189         struct ocfs2_refcount_rec *rec = &rb->rf_records.rl_recs[index];
2190
2191         BUG_ON(cpos < le64_to_cpu(rec->r_cpos));
2192         BUG_ON(cpos + len >
2193                le64_to_cpu(rec->r_cpos) + le32_to_cpu(rec->r_clusters));
2194
2195         trace_ocfs2_decrease_refcount_rec(
2196                 (unsigned long long)ocfs2_metadata_cache_owner(ci),
2197                 (unsigned long long)cpos, len);
2198
2199         if (cpos == le64_to_cpu(rec->r_cpos) &&
2200             len == le32_to_cpu(rec->r_clusters))
2201                 ret = ocfs2_change_refcount_rec(handle, ci,
2202                                                 ref_leaf_bh, index, 1, -1);
2203         else {
2204                 struct ocfs2_refcount_rec split = *rec;
2205                 split.r_cpos = cpu_to_le64(cpos);
2206                 split.r_clusters = cpu_to_le32(len);
2207
2208                 le32_add_cpu(&split.r_refcount, -1);
2209
2210                 ret = ocfs2_split_refcount_rec(handle, ci,
2211                                                ref_root_bh, ref_leaf_bh,
2212                                                &split, index, 1,
2213                                                meta_ac, dealloc);
2214         }
2215
2216         if (ret) {
2217                 mlog_errno(ret);
2218                 goto out;
2219         }
2220
2221         /* Remove the leaf refcount block if it contains no refcount record. */
2222         if (!rb->rf_records.rl_used && ref_leaf_bh != ref_root_bh) {
2223                 ret = ocfs2_remove_refcount_extent(handle, ci, ref_root_bh,
2224                                                    ref_leaf_bh, meta_ac,
2225                                                    dealloc);
2226                 if (ret)
2227                         mlog_errno(ret);
2228         }
2229
2230 out:
2231         return ret;
2232 }
2233
2234 static int __ocfs2_decrease_refcount(handle_t *handle,
2235                                      struct ocfs2_caching_info *ci,
2236                                      struct buffer_head *ref_root_bh,
2237                                      u64 cpos, u32 len,
2238                                      struct ocfs2_alloc_context *meta_ac,
2239                                      struct ocfs2_cached_dealloc_ctxt *dealloc,
2240                                      int delete)
2241 {
2242         int ret = 0, index = 0;
2243         struct ocfs2_refcount_rec rec;
2244         unsigned int r_count = 0, r_len;
2245         struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
2246         struct buffer_head *ref_leaf_bh = NULL;
2247
2248         trace_ocfs2_decrease_refcount(
2249                 (unsigned long long)ocfs2_metadata_cache_owner(ci),
2250                 (unsigned long long)cpos, len, delete);
2251
2252         while (len) {
2253                 ret = ocfs2_get_refcount_rec(ci, ref_root_bh,
2254                                              cpos, len, &rec, &index,
2255                                              &ref_leaf_bh);
2256                 if (ret) {
2257                         mlog_errno(ret);
2258                         goto out;
2259                 }
2260
2261                 r_count = le32_to_cpu(rec.r_refcount);
2262                 BUG_ON(r_count == 0);
2263                 if (!delete)
2264                         BUG_ON(r_count > 1);
2265
2266                 r_len = min((u64)(cpos + len), le64_to_cpu(rec.r_cpos) +
2267                               le32_to_cpu(rec.r_clusters)) - cpos;
2268
2269                 ret = ocfs2_decrease_refcount_rec(handle, ci, ref_root_bh,
2270                                                   ref_leaf_bh, index,
2271                                                   cpos, r_len,
2272                                                   meta_ac, dealloc);
2273                 if (ret) {
2274                         mlog_errno(ret);
2275                         goto out;
2276                 }
2277
2278                 if (le32_to_cpu(rec.r_refcount) == 1 && delete) {
2279                         ret = ocfs2_cache_cluster_dealloc(dealloc,
2280                                           ocfs2_clusters_to_blocks(sb, cpos),
2281                                                           r_len);
2282                         if (ret) {
2283                                 mlog_errno(ret);
2284                                 goto out;
2285                         }
2286                 }
2287
2288                 cpos += r_len;
2289                 len -= r_len;
2290                 brelse(ref_leaf_bh);
2291                 ref_leaf_bh = NULL;
2292         }
2293
2294 out:
2295         brelse(ref_leaf_bh);
2296         return ret;
2297 }
2298
2299 /* Caller must hold refcount tree lock. */
2300 int ocfs2_decrease_refcount(struct inode *inode,
2301                             handle_t *handle, u32 cpos, u32 len,
2302                             struct ocfs2_alloc_context *meta_ac,
2303                             struct ocfs2_cached_dealloc_ctxt *dealloc,
2304                             int delete)
2305 {
2306         int ret;
2307         u64 ref_blkno;
2308         struct ocfs2_inode_info *oi = OCFS2_I(inode);
2309         struct buffer_head *ref_root_bh = NULL;
2310         struct ocfs2_refcount_tree *tree;
2311
2312         BUG_ON(!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL));
2313
2314         ret = ocfs2_get_refcount_block(inode, &ref_blkno);
2315         if (ret) {
2316                 mlog_errno(ret);
2317                 goto out;
2318         }
2319
2320         ret = ocfs2_get_refcount_tree(OCFS2_SB(inode->i_sb), ref_blkno, &tree);
2321         if (ret) {
2322                 mlog_errno(ret);
2323                 goto out;
2324         }
2325
2326         ret = ocfs2_read_refcount_block(&tree->rf_ci, tree->rf_blkno,
2327                                         &ref_root_bh);
2328         if (ret) {
2329                 mlog_errno(ret);
2330                 goto out;
2331         }
2332
2333         ret = __ocfs2_decrease_refcount(handle, &tree->rf_ci, ref_root_bh,
2334                                         cpos, len, meta_ac, dealloc, delete);
2335         if (ret)
2336                 mlog_errno(ret);
2337 out:
2338         brelse(ref_root_bh);
2339         return ret;
2340 }
2341
2342 /*
2343  * Mark the already-existing extent at cpos as refcounted for len clusters.
2344  * This adds the refcount extent flag.
2345  *
2346  * If the existing extent is larger than the request, initiate a
2347  * split. An attempt will be made at merging with adjacent extents.
2348  *
2349  * The caller is responsible for passing down meta_ac if we'll need it.
2350  */
2351 static int ocfs2_mark_extent_refcounted(struct inode *inode,
2352                                 struct ocfs2_extent_tree *et,
2353                                 handle_t *handle, u32 cpos,
2354                                 u32 len, u32 phys,
2355                                 struct ocfs2_alloc_context *meta_ac,
2356                                 struct ocfs2_cached_dealloc_ctxt *dealloc)
2357 {
2358         int ret;
2359
2360         trace_ocfs2_mark_extent_refcounted(OCFS2_I(inode)->ip_blkno,
2361                                            cpos, len, phys);
2362
2363         if (!ocfs2_refcount_tree(OCFS2_SB(inode->i_sb))) {
2364                 ocfs2_error(inode->i_sb, "Inode %lu want to use refcount "
2365                             "tree, but the feature bit is not set in the "
2366                             "super block.", inode->i_ino);
2367                 ret = -EROFS;
2368                 goto out;
2369         }
2370
2371         ret = ocfs2_change_extent_flag(handle, et, cpos,
2372                                        len, phys, meta_ac, dealloc,
2373                                        OCFS2_EXT_REFCOUNTED, 0);
2374         if (ret)
2375                 mlog_errno(ret);
2376
2377 out:
2378         return ret;
2379 }
2380
2381 /*
2382  * Given some contiguous physical clusters, calculate what we need
2383  * for modifying their refcount.
2384  */
2385 static int ocfs2_calc_refcount_meta_credits(struct super_block *sb,
2386                                             struct ocfs2_caching_info *ci,
2387                                             struct buffer_head *ref_root_bh,
2388                                             u64 start_cpos,
2389                                             u32 clusters,
2390                                             int *meta_add,
2391                                             int *credits)
2392 {
2393         int ret = 0, index, ref_blocks = 0, recs_add = 0;
2394         u64 cpos = start_cpos;
2395         struct ocfs2_refcount_block *rb;
2396         struct ocfs2_refcount_rec rec;
2397         struct buffer_head *ref_leaf_bh = NULL, *prev_bh = NULL;
2398         u32 len;
2399
2400         while (clusters) {
2401                 ret = ocfs2_get_refcount_rec(ci, ref_root_bh,
2402                                              cpos, clusters, &rec,
2403                                              &index, &ref_leaf_bh);
2404                 if (ret) {
2405                         mlog_errno(ret);
2406                         goto out;
2407                 }
2408
2409                 if (ref_leaf_bh != prev_bh) {
2410                         /*
2411                          * Now we encounter a new leaf block, so calculate
2412                          * whether we need to extend the old leaf.
2413                          */
2414                         if (prev_bh) {
2415                                 rb = (struct ocfs2_refcount_block *)
2416                                                         prev_bh->b_data;
2417
2418                                 if (le16_to_cpu(rb->rf_records.rl_used) +
2419                                     recs_add >
2420                                     le16_to_cpu(rb->rf_records.rl_count))
2421                                         ref_blocks++;
2422                         }
2423
2424                         recs_add = 0;
2425                         *credits += 1;
2426                         brelse(prev_bh);
2427                         prev_bh = ref_leaf_bh;
2428                         get_bh(prev_bh);
2429                 }
2430
2431                 trace_ocfs2_calc_refcount_meta_credits_iterate(
2432                                 recs_add, (unsigned long long)cpos, clusters,
2433                                 (unsigned long long)le64_to_cpu(rec.r_cpos),
2434                                 le32_to_cpu(rec.r_clusters),
2435                                 le32_to_cpu(rec.r_refcount), index);
2436
2437                 len = min((u64)cpos + clusters, le64_to_cpu(rec.r_cpos) +
2438                           le32_to_cpu(rec.r_clusters)) - cpos;
2439                 /*
2440                  * We record all the records which will be inserted to the
2441                  * same refcount block, so that we can tell exactly whether
2442                  * we need a new refcount block or not.
2443                  *
2444                  * If we will insert a new one, this is easy and only happens
2445                  * during adding refcounted flag to the extent, so we don't
2446                  * have a chance of spliting. We just need one record.
2447                  *
2448                  * If the refcount rec already exists, that would be a little
2449                  * complicated. we may have to:
2450                  * 1) split at the beginning if the start pos isn't aligned.
2451                  *    we need 1 more record in this case.
2452                  * 2) split int the end if the end pos isn't aligned.
2453                  *    we need 1 more record in this case.
2454                  * 3) split in the middle because of file system fragmentation.
2455                  *    we need 2 more records in this case(we can't detect this
2456                  *    beforehand, so always think of the worst case).
2457                  */
2458                 if (rec.r_refcount) {
2459                         recs_add += 2;
2460                         /* Check whether we need a split at the beginning. */
2461                         if (cpos == start_cpos &&
2462                             cpos != le64_to_cpu(rec.r_cpos))
2463                                 recs_add++;
2464
2465                         /* Check whether we need a split in the end. */
2466                         if (cpos + clusters < le64_to_cpu(rec.r_cpos) +
2467                             le32_to_cpu(rec.r_clusters))
2468                                 recs_add++;
2469                 } else
2470                         recs_add++;
2471
2472                 brelse(ref_leaf_bh);
2473                 ref_leaf_bh = NULL;
2474                 clusters -= len;
2475                 cpos += len;
2476         }
2477
2478         if (prev_bh) {
2479                 rb = (struct ocfs2_refcount_block *)prev_bh->b_data;
2480
2481                 if (le16_to_cpu(rb->rf_records.rl_used) + recs_add >
2482                     le16_to_cpu(rb->rf_records.rl_count))
2483                         ref_blocks++;
2484
2485                 *credits += 1;
2486         }
2487
2488         if (!ref_blocks)
2489                 goto out;
2490
2491         *meta_add += ref_blocks;
2492         *credits += ref_blocks;
2493
2494         /*
2495          * So we may need ref_blocks to insert into the tree.
2496          * That also means we need to change the b-tree and add that number
2497          * of records since we never merge them.
2498          * We need one more block for expansion since the new created leaf
2499          * block is also full and needs split.
2500          */
2501         rb = (struct ocfs2_refcount_block *)ref_root_bh->b_data;
2502         if (le32_to_cpu(rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL) {
2503                 struct ocfs2_extent_tree et;
2504
2505                 ocfs2_init_refcount_extent_tree(&et, ci, ref_root_bh);
2506                 *meta_add += ocfs2_extend_meta_needed(et.et_root_el);
2507                 *credits += ocfs2_calc_extend_credits(sb,
2508                                                       et.et_root_el);
2509         } else {
2510                 *credits += OCFS2_EXPAND_REFCOUNT_TREE_CREDITS;
2511                 *meta_add += 1;
2512         }
2513
2514 out:
2515
2516         trace_ocfs2_calc_refcount_meta_credits(
2517                 (unsigned long long)start_cpos, clusters,
2518                 *meta_add, *credits);
2519         brelse(ref_leaf_bh);
2520         brelse(prev_bh);
2521         return ret;
2522 }
2523
2524 /*
2525  * For refcount tree, we will decrease some contiguous clusters
2526  * refcount count, so just go through it to see how many blocks
2527  * we gonna touch and whether we need to create new blocks.
2528  *
2529  * Normally the refcount blocks store these refcount should be
2530  * contiguous also, so that we can get the number easily.
2531  * We will at most add split 2 refcount records and 2 more
2532  * refcount blocks, so just check it in a rough way.
2533  *
2534  * Caller must hold refcount tree lock.
2535  */
2536 int ocfs2_prepare_refcount_change_for_del(struct inode *inode,
2537                                           u64 refcount_loc,
2538                                           u64 phys_blkno,
2539                                           u32 clusters,
2540                                           int *credits,
2541                                           int *ref_blocks)
2542 {
2543         int ret;
2544         struct ocfs2_inode_info *oi = OCFS2_I(inode);
2545         struct buffer_head *ref_root_bh = NULL;
2546         struct ocfs2_refcount_tree *tree;
2547         u64 start_cpos = ocfs2_blocks_to_clusters(inode->i_sb, phys_blkno);
2548
2549         if (!ocfs2_refcount_tree(OCFS2_SB(inode->i_sb))) {
2550                 ocfs2_error(inode->i_sb, "Inode %lu want to use refcount "
2551                             "tree, but the feature bit is not set in the "
2552                             "super block.", inode->i_ino);
2553                 ret = -EROFS;
2554                 goto out;
2555         }
2556
2557         BUG_ON(!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL));
2558
2559         ret = ocfs2_get_refcount_tree(OCFS2_SB(inode->i_sb),
2560                                       refcount_loc, &tree);
2561         if (ret) {
2562                 mlog_errno(ret);
2563                 goto out;
2564         }
2565
2566         ret = ocfs2_read_refcount_block(&tree->rf_ci, refcount_loc,
2567                                         &ref_root_bh);
2568         if (ret) {
2569                 mlog_errno(ret);
2570                 goto out;
2571         }
2572
2573         ret = ocfs2_calc_refcount_meta_credits(inode->i_sb,
2574                                                &tree->rf_ci,
2575                                                ref_root_bh,
2576                                                start_cpos, clusters,
2577                                                ref_blocks, credits);
2578         if (ret) {
2579                 mlog_errno(ret);
2580                 goto out;
2581         }
2582
2583         trace_ocfs2_prepare_refcount_change_for_del(*ref_blocks, *credits);
2584
2585 out:
2586         brelse(ref_root_bh);
2587         return ret;
2588 }
2589
2590 #define MAX_CONTIG_BYTES        1048576
2591
2592 static inline unsigned int ocfs2_cow_contig_clusters(struct super_block *sb)
2593 {
2594         return ocfs2_clusters_for_bytes(sb, MAX_CONTIG_BYTES);
2595 }
2596
2597 static inline unsigned int ocfs2_cow_contig_mask(struct super_block *sb)
2598 {
2599         return ~(ocfs2_cow_contig_clusters(sb) - 1);
2600 }
2601
2602 /*
2603  * Given an extent that starts at 'start' and an I/O that starts at 'cpos',
2604  * find an offset (start + (n * contig_clusters)) that is closest to cpos
2605  * while still being less than or equal to it.
2606  *
2607  * The goal is to break the extent at a multiple of contig_clusters.
2608  */
2609 static inline unsigned int ocfs2_cow_align_start(struct super_block *sb,
2610                                                  unsigned int start,
2611                                                  unsigned int cpos)
2612 {
2613         BUG_ON(start > cpos);
2614
2615         return start + ((cpos - start) & ocfs2_cow_contig_mask(sb));
2616 }
2617
2618 /*
2619  * Given a cluster count of len, pad it out so that it is a multiple
2620  * of contig_clusters.
2621  */
2622 static inline unsigned int ocfs2_cow_align_length(struct super_block *sb,
2623                                                   unsigned int len)
2624 {
2625         unsigned int padded =
2626                 (len + (ocfs2_cow_contig_clusters(sb) - 1)) &
2627                 ocfs2_cow_contig_mask(sb);
2628
2629         /* Did we wrap? */
2630         if (padded < len)
2631                 padded = UINT_MAX;
2632
2633         return padded;
2634 }
2635
2636 /*
2637  * Calculate out the start and number of virtual clusters we need to to CoW.
2638  *
2639  * cpos is vitual start cluster position we want to do CoW in a
2640  * file and write_len is the cluster length.
2641  * max_cpos is the place where we want to stop CoW intentionally.
2642  *
2643  * Normal we will start CoW from the beginning of extent record cotaining cpos.
2644  * We try to break up extents on boundaries of MAX_CONTIG_BYTES so that we
2645  * get good I/O from the resulting extent tree.
2646  */
2647 static int ocfs2_refcount_cal_cow_clusters(struct inode *inode,
2648                                            struct ocfs2_extent_list *el,
2649                                            u32 cpos,
2650                                            u32 write_len,
2651                                            u32 max_cpos,
2652                                            u32 *cow_start,
2653                                            u32 *cow_len)
2654 {
2655         int ret = 0;
2656         int tree_height = le16_to_cpu(el->l_tree_depth), i;
2657         struct buffer_head *eb_bh = NULL;
2658         struct ocfs2_extent_block *eb = NULL;
2659         struct ocfs2_extent_rec *rec;
2660         unsigned int want_clusters, rec_end = 0;
2661         int contig_clusters = ocfs2_cow_contig_clusters(inode->i_sb);
2662         int leaf_clusters;
2663
2664         BUG_ON(cpos + write_len > max_cpos);
2665
2666         if (tree_height > 0) {
2667                 ret = ocfs2_find_leaf(INODE_CACHE(inode), el, cpos, &eb_bh);
2668                 if (ret) {
2669                         mlog_errno(ret);
2670                         goto out;
2671                 }
2672
2673                 eb = (struct ocfs2_extent_block *) eb_bh->b_data;
2674                 el = &eb->h_list;
2675
2676                 if (el->l_tree_depth) {
2677                         ocfs2_error(inode->i_sb,
2678                                     "Inode %lu has non zero tree depth in "
2679                                     "leaf block %llu\n", inode->i_ino,
2680                                     (unsigned long long)eb_bh->b_blocknr);
2681                         ret = -EROFS;
2682                         goto out;
2683                 }
2684         }
2685
2686         *cow_len = 0;
2687         for (i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
2688                 rec = &el->l_recs[i];
2689
2690                 if (ocfs2_is_empty_extent(rec)) {
2691                         mlog_bug_on_msg(i != 0, "Inode %lu has empty record in "
2692                                         "index %d\n", inode->i_ino, i);
2693                         continue;
2694                 }
2695
2696                 if (le32_to_cpu(rec->e_cpos) +
2697                     le16_to_cpu(rec->e_leaf_clusters) <= cpos)
2698                         continue;
2699
2700                 if (*cow_len == 0) {
2701                         /*
2702                          * We should find a refcounted record in the
2703                          * first pass.
2704                          */
2705                         BUG_ON(!(rec->e_flags & OCFS2_EXT_REFCOUNTED));
2706                         *cow_start = le32_to_cpu(rec->e_cpos);
2707                 }
2708
2709                 /*
2710                  * If we encounter a hole, a non-refcounted record or
2711                  * pass the max_cpos, stop the search.
2712                  */
2713                 if ((!(rec->e_flags & OCFS2_EXT_REFCOUNTED)) ||
2714                     (*cow_len && rec_end != le32_to_cpu(rec->e_cpos)) ||
2715                     (max_cpos <= le32_to_cpu(rec->e_cpos)))
2716                         break;
2717
2718                 leaf_clusters = le16_to_cpu(rec->e_leaf_clusters);
2719                 rec_end = le32_to_cpu(rec->e_cpos) + leaf_clusters;
2720                 if (rec_end > max_cpos) {
2721                         rec_end = max_cpos;
2722                         leaf_clusters = rec_end - le32_to_cpu(rec->e_cpos);
2723                 }
2724
2725                 /*
2726                  * How many clusters do we actually need from
2727                  * this extent?  First we see how many we actually
2728                  * need to complete the write.  If that's smaller
2729                  * than contig_clusters, we try for contig_clusters.
2730                  */
2731                 if (!*cow_len)
2732                         want_clusters = write_len;
2733                 else
2734                         want_clusters = (cpos + write_len) -
2735                                 (*cow_start + *cow_len);
2736                 if (want_clusters < contig_clusters)
2737                         want_clusters = contig_clusters;
2738
2739                 /*
2740                  * If the write does not cover the whole extent, we
2741                  * need to calculate how we're going to split the extent.
2742                  * We try to do it on contig_clusters boundaries.
2743                  *
2744                  * Any extent smaller than contig_clusters will be
2745                  * CoWed in its entirety.
2746                  */
2747                 if (leaf_clusters <= contig_clusters)
2748                         *cow_len += leaf_clusters;
2749                 else if (*cow_len || (*cow_start == cpos)) {
2750                         /*
2751                          * This extent needs to be CoW'd from its
2752                          * beginning, so all we have to do is compute
2753                          * how many clusters to grab.  We align
2754                          * want_clusters to the edge of contig_clusters
2755                          * to get better I/O.
2756                          */
2757                         want_clusters = ocfs2_cow_align_length(inode->i_sb,
2758                                                                want_clusters);
2759
2760                         if (leaf_clusters < want_clusters)
2761                                 *cow_len += leaf_clusters;
2762                         else
2763                                 *cow_len += want_clusters;
2764                 } else if ((*cow_start + contig_clusters) >=
2765                            (cpos + write_len)) {
2766                         /*
2767                          * Breaking off contig_clusters at the front
2768                          * of the extent will cover our write.  That's
2769                          * easy.
2770                          */
2771                         *cow_len = contig_clusters;
2772                 } else if ((rec_end - cpos) <= contig_clusters) {
2773                         /*
2774                          * Breaking off contig_clusters at the tail of
2775                          * this extent will cover cpos.
2776                          */
2777                         *cow_start = rec_end - contig_clusters;
2778                         *cow_len = contig_clusters;
2779                 } else if ((rec_end - cpos) <= want_clusters) {
2780                         /*
2781                          * While we can't fit the entire write in this
2782                          * extent, we know that the write goes from cpos
2783                          * to the end of the extent.  Break that off.
2784                          * We try to break it at some multiple of
2785                          * contig_clusters from the front of the extent.
2786                          * Failing that (ie, cpos is within
2787                          * contig_clusters of the front), we'll CoW the
2788                          * entire extent.
2789                          */
2790                         *cow_start = ocfs2_cow_align_start(inode->i_sb,
2791                                                            *cow_start, cpos);
2792                         *cow_len = rec_end - *cow_start;
2793                 } else {
2794                         /*
2795                          * Ok, the entire write lives in the middle of
2796                          * this extent.  Let's try to slice the extent up
2797                          * nicely.  Optimally, our CoW region starts at
2798                          * m*contig_clusters from the beginning of the
2799                          * extent and goes for n*contig_clusters,
2800                          * covering the entire write.
2801                          */
2802                         *cow_start = ocfs2_cow_align_start(inode->i_sb,
2803                                                            *cow_start, cpos);
2804
2805                         want_clusters = (cpos + write_len) - *cow_start;
2806                         want_clusters = ocfs2_cow_align_length(inode->i_sb,
2807                                                                want_clusters);
2808                         if (*cow_start + want_clusters <= rec_end)
2809                                 *cow_len = want_clusters;
2810                         else
2811                                 *cow_len = rec_end - *cow_start;
2812                 }
2813
2814                 /* Have we covered our entire write yet? */
2815                 if ((*cow_start + *cow_len) >= (cpos + write_len))
2816                         break;
2817
2818                 /*
2819                  * If we reach the end of the extent block and don't get enough
2820                  * clusters, continue with the next extent block if possible.
2821                  */
2822                 if (i + 1 == le16_to_cpu(el->l_next_free_rec) &&
2823                     eb && eb->h_next_leaf_blk) {
2824                         brelse(eb_bh);
2825                         eb_bh = NULL;
2826
2827                         ret = ocfs2_read_extent_block(INODE_CACHE(inode),
2828                                                le64_to_cpu(eb->h_next_leaf_blk),
2829                                                &eb_bh);
2830                         if (ret) {
2831                                 mlog_errno(ret);
2832                                 goto out;
2833                         }
2834
2835                         eb = (struct ocfs2_extent_block *) eb_bh->b_data;
2836                         el = &eb->h_list;
2837                         i = -1;
2838                 }
2839         }
2840
2841 out:
2842         brelse(eb_bh);
2843         return ret;
2844 }
2845
2846 /*
2847  * Prepare meta_ac, data_ac and calculate credits when we want to add some
2848  * num_clusters in data_tree "et" and change the refcount for the old
2849  * clusters(starting form p_cluster) in the refcount tree.
2850  *
2851  * Note:
2852  * 1. since we may split the old tree, so we at most will need num_clusters + 2
2853  *    more new leaf records.
2854  * 2. In some case, we may not need to reserve new clusters(e.g, reflink), so
2855  *    just give data_ac = NULL.
2856  */
2857 static int ocfs2_lock_refcount_allocators(struct super_block *sb,
2858                                         u32 p_cluster, u32 num_clusters,
2859                                         struct ocfs2_extent_tree *et,
2860                                         struct ocfs2_caching_info *ref_ci,
2861                                         struct buffer_head *ref_root_bh,
2862                                         struct ocfs2_alloc_context **meta_ac,
2863                                         struct ocfs2_alloc_context **data_ac,
2864                                         int *credits)
2865 {
2866         int ret = 0, meta_add = 0;
2867         int num_free_extents = ocfs2_num_free_extents(OCFS2_SB(sb), et);
2868
2869         if (num_free_extents < 0) {
2870                 ret = num_free_extents;
2871                 mlog_errno(ret);
2872                 goto out;
2873         }
2874
2875         if (num_free_extents < num_clusters + 2)
2876                 meta_add =
2877                         ocfs2_extend_meta_needed(et->et_root_el);
2878
2879         *credits += ocfs2_calc_extend_credits(sb, et->et_root_el);
2880
2881         ret = ocfs2_calc_refcount_meta_credits(sb, ref_ci, ref_root_bh,
2882                                                p_cluster, num_clusters,
2883                                                &meta_add, credits);
2884         if (ret) {
2885                 mlog_errno(ret);
2886                 goto out;
2887         }
2888
2889         trace_ocfs2_lock_refcount_allocators(meta_add, *credits);
2890         ret = ocfs2_reserve_new_metadata_blocks(OCFS2_SB(sb), meta_add,
2891                                                 meta_ac);
2892         if (ret) {
2893                 mlog_errno(ret);
2894                 goto out;
2895         }
2896
2897         if (data_ac) {
2898                 ret = ocfs2_reserve_clusters(OCFS2_SB(sb), num_clusters,
2899                                              data_ac);
2900                 if (ret)
2901                         mlog_errno(ret);
2902         }
2903
2904 out:
2905         if (ret) {
2906                 if (*meta_ac) {
2907                         ocfs2_free_alloc_context(*meta_ac);
2908                         *meta_ac = NULL;
2909                 }
2910         }
2911
2912         return ret;
2913 }
2914
2915 static int ocfs2_clear_cow_buffer(handle_t *handle, struct buffer_head *bh)
2916 {
2917         BUG_ON(buffer_dirty(bh));
2918
2919         clear_buffer_mapped(bh);
2920
2921         return 0;
2922 }
2923
2924 int ocfs2_duplicate_clusters_by_page(handle_t *handle,
2925                                      struct inode *inode,
2926                                      u32 cpos, u32 old_cluster,
2927                                      u32 new_cluster, u32 new_len)
2928 {
2929         int ret = 0, partial;
2930         struct super_block *sb = inode->i_sb;
2931         u64 new_block = ocfs2_clusters_to_blocks(sb, new_cluster);
2932         struct page *page;
2933         pgoff_t page_index;
2934         unsigned int from, to, readahead_pages;
2935         loff_t offset, end, map_end;
2936         struct address_space *mapping = inode->i_mapping;
2937
2938         trace_ocfs2_duplicate_clusters_by_page(cpos, old_cluster,
2939                                                new_cluster, new_len);
2940
2941         readahead_pages =
2942                 (ocfs2_cow_contig_clusters(sb) <<
2943                  OCFS2_SB(sb)->s_clustersize_bits) >> PAGE_CACHE_SHIFT;
2944         offset = ((loff_t)cpos) << OCFS2_SB(sb)->s_clustersize_bits;
2945         end = offset + (new_len << OCFS2_SB(sb)->s_clustersize_bits);
2946         /*
2947          * We only duplicate pages until we reach the page contains i_size - 1.
2948          * So trim 'end' to i_size.
2949          */
2950         if (end > i_size_read(inode))
2951                 end = i_size_read(inode);
2952
2953         while (offset < end) {
2954                 page_index = offset >> PAGE_CACHE_SHIFT;
2955                 map_end = ((loff_t)page_index + 1) << PAGE_CACHE_SHIFT;
2956                 if (map_end > end)
2957                         map_end = end;
2958
2959                 /* from, to is the offset within the page. */
2960                 from = offset & (PAGE_CACHE_SIZE - 1);
2961                 to = PAGE_CACHE_SIZE;
2962                 if (map_end & (PAGE_CACHE_SIZE - 1))
2963                         to = map_end & (PAGE_CACHE_SIZE - 1);
2964
2965                 page = find_or_create_page(mapping, page_index, GFP_NOFS);
2966                 if (!page) {
2967                         ret = -ENOMEM;
2968                         mlog_errno(ret);
2969                         break;
2970                 }
2971
2972                 /*
2973                  * In case PAGE_CACHE_SIZE <= CLUSTER_SIZE, This page
2974                  * can't be dirtied before we CoW it out.
2975                  */
2976                 if (PAGE_CACHE_SIZE <= OCFS2_SB(sb)->s_clustersize)
2977                         BUG_ON(PageDirty(page));
2978
2979                 if (!PageUptodate(page)) {
2980                         ret = block_read_full_page(page, ocfs2_get_block);
2981                         if (ret) {
2982                                 mlog_errno(ret);
2983                                 goto unlock;
2984                         }
2985                         lock_page(page);
2986                 }
2987
2988                 if (page_has_buffers(page)) {
2989                         ret = walk_page_buffers(handle, page_buffers(page),
2990                                                 from, to, &partial,
2991                                                 ocfs2_clear_cow_buffer);
2992                         if (ret) {
2993                                 mlog_errno(ret);
2994                                 goto unlock;
2995                         }
2996                 }
2997
2998                 ocfs2_map_and_dirty_page(inode,
2999                                          handle, from, to,
3000                                          page, 0, &new_block);
3001                 mark_page_accessed(page);
3002 unlock:
3003                 unlock_page(page);
3004                 page_cache_release(page);
3005                 page = NULL;
3006                 offset = map_end;
3007                 if (ret)
3008                         break;
3009         }
3010
3011         return ret;
3012 }
3013
3014 int ocfs2_duplicate_clusters_by_jbd(handle_t *handle,
3015                                     struct inode *inode,
3016                                     u32 cpos, u32 old_cluster,
3017                                     u32 new_cluster, u32 new_len)
3018 {
3019         int ret = 0;
3020         struct super_block *sb = inode->i_sb;
3021         struct ocfs2_caching_info *ci = INODE_CACHE(inode);
3022         int i, blocks = ocfs2_clusters_to_blocks(sb, new_len);
3023         u64 old_block = ocfs2_clusters_to_blocks(sb, old_cluster);
3024         u64 new_block = ocfs2_clusters_to_blocks(sb, new_cluster);
3025         struct ocfs2_super *osb = OCFS2_SB(sb);
3026         struct buffer_head *old_bh = NULL;
3027         struct buffer_head *new_bh = NULL;
3028
3029         trace_ocfs2_duplicate_clusters_by_page(cpos, old_cluster,
3030                                                new_cluster, new_len);
3031
3032         for (i = 0; i < blocks; i++, old_block++, new_block++) {
3033                 new_bh = sb_getblk(osb->sb, new_block);
3034                 if (new_bh == NULL) {
3035                         ret = -ENOMEM;
3036                         mlog_errno(ret);
3037                         break;
3038                 }
3039
3040                 ocfs2_set_new_buffer_uptodate(ci, new_bh);
3041
3042                 ret = ocfs2_read_block(ci, old_block, &old_bh, NULL);
3043                 if (ret) {
3044                         mlog_errno(ret);
3045                         break;
3046                 }
3047
3048                 ret = ocfs2_journal_access(handle, ci, new_bh,
3049                                            OCFS2_JOURNAL_ACCESS_CREATE);
3050                 if (ret) {
3051                         mlog_errno(ret);
3052                         break;
3053                 }
3054
3055                 memcpy(new_bh->b_data, old_bh->b_data, sb->s_blocksize);
3056                 ocfs2_journal_dirty(handle, new_bh);
3057
3058                 brelse(new_bh);
3059                 brelse(old_bh);
3060                 new_bh = NULL;
3061                 old_bh = NULL;
3062         }
3063
3064         brelse(new_bh);
3065         brelse(old_bh);
3066         return ret;
3067 }
3068
3069 static int ocfs2_clear_ext_refcount(handle_t *handle,
3070                                     struct ocfs2_extent_tree *et,
3071                                     u32 cpos, u32 p_cluster, u32 len,
3072                                     unsigned int ext_flags,
3073                                     struct ocfs2_alloc_context *meta_ac,
3074                                     struct ocfs2_cached_dealloc_ctxt *dealloc)
3075 {
3076         int ret, index;
3077         struct ocfs2_extent_rec replace_rec;
3078         struct ocfs2_path *path = NULL;
3079         struct ocfs2_extent_list *el;
3080         struct super_block *sb = ocfs2_metadata_cache_get_super(et->et_ci);
3081         u64 ino = ocfs2_metadata_cache_owner(et->et_ci);
3082
3083         trace_ocfs2_clear_ext_refcount((unsigned long long)ino,
3084                                        cpos, len, p_cluster, ext_flags);
3085
3086         memset(&replace_rec, 0, sizeof(replace_rec));
3087         replace_rec.e_cpos = cpu_to_le32(cpos);
3088         replace_rec.e_leaf_clusters = cpu_to_le16(len);
3089         replace_rec.e_blkno = cpu_to_le64(ocfs2_clusters_to_blocks(sb,
3090                                                                    p_cluster));
3091         replace_rec.e_flags = ext_flags;
3092         replace_rec.e_flags &= ~OCFS2_EXT_REFCOUNTED;
3093
3094         path = ocfs2_new_path_from_et(et);
3095         if (!path) {
3096                 ret = -ENOMEM;
3097                 mlog_errno(ret);
3098                 goto out;
3099         }
3100
3101         ret = ocfs2_find_path(et->et_ci, path, cpos);
3102         if (ret) {
3103                 mlog_errno(ret);
3104                 goto out;
3105         }
3106
3107         el = path_leaf_el(path);
3108
3109         index = ocfs2_search_extent_list(el, cpos);
3110         if (index == -1) {
3111                 ocfs2_error(sb,
3112                             "Inode %llu has an extent at cpos %u which can no "
3113                             "longer be found.\n",
3114                             (unsigned long long)ino, cpos);
3115                 ret = -EROFS;
3116                 goto out;
3117         }
3118
3119         ret = ocfs2_split_extent(handle, et, path, index,
3120                                  &replace_rec, meta_ac, dealloc);
3121         if (ret)
3122                 mlog_errno(ret);
3123
3124 out:
3125         ocfs2_free_path(path);
3126         return ret;
3127 }
3128
3129 static int ocfs2_replace_clusters(handle_t *handle,
3130                                   struct ocfs2_cow_context *context,
3131                                   u32 cpos, u32 old,
3132                                   u32 new, u32 len,
3133                                   unsigned int ext_flags)
3134 {
3135         int ret;
3136         struct ocfs2_caching_info *ci = context->data_et.et_ci;
3137         u64 ino = ocfs2_metadata_cache_owner(ci);
3138
3139         trace_ocfs2_replace_clusters((unsigned long long)ino,
3140                                      cpos, old, new, len, ext_flags);
3141
3142         /*If the old clusters is unwritten, no need to duplicate. */
3143         if (!(ext_flags & OCFS2_EXT_UNWRITTEN)) {
3144                 ret = context->cow_duplicate_clusters(handle, context->inode,
3145                                                       cpos, old, new, len);
3146                 if (ret) {
3147                         mlog_errno(ret);
3148                         goto out;
3149                 }
3150         }
3151
3152         ret = ocfs2_clear_ext_refcount(handle, &context->data_et,
3153                                        cpos, new, len, ext_flags,
3154                                        context->meta_ac, &context->dealloc);
3155         if (ret)
3156                 mlog_errno(ret);
3157 out:
3158         return ret;
3159 }
3160
3161 int ocfs2_cow_sync_writeback(struct super_block *sb,
3162                              struct inode *inode,
3163                              u32 cpos, u32 num_clusters)
3164 {
3165         int ret = 0;
3166         loff_t offset, end, map_end;
3167         pgoff_t page_index;
3168         struct page *page;
3169
3170         if (ocfs2_should_order_data(inode))
3171                 return 0;
3172
3173         offset = ((loff_t)cpos) << OCFS2_SB(sb)->s_clustersize_bits;
3174         end = offset + (num_clusters << OCFS2_SB(sb)->s_clustersize_bits);
3175
3176         ret = filemap_fdatawrite_range(inode->i_mapping,
3177                                        offset, end - 1);
3178         if (ret < 0) {
3179                 mlog_errno(ret);
3180                 return ret;
3181         }
3182
3183         while (offset < end) {
3184                 page_index = offset >> PAGE_CACHE_SHIFT;
3185                 map_end = ((loff_t)page_index + 1) << PAGE_CACHE_SHIFT;
3186                 if (map_end > end)
3187                         map_end = end;
3188
3189                 page = find_or_create_page(inode->i_mapping,
3190                                            page_index, GFP_NOFS);
3191                 BUG_ON(!page);
3192
3193                 wait_on_page_writeback(page);
3194                 if (PageError(page)) {
3195                         ret = -EIO;
3196                         mlog_errno(ret);
3197                 } else
3198                         mark_page_accessed(page);
3199
3200                 unlock_page(page);
3201                 page_cache_release(page);
3202                 page = NULL;
3203                 offset = map_end;
3204                 if (ret)
3205                         break;
3206         }
3207
3208         return ret;
3209 }
3210
3211 static int ocfs2_di_get_clusters(struct ocfs2_cow_context *context,
3212                                  u32 v_cluster, u32 *p_cluster,
3213                                  u32 *num_clusters,
3214                                  unsigned int *extent_flags)
3215 {
3216         return ocfs2_get_clusters(context->inode, v_cluster, p_cluster,
3217                                   num_clusters, extent_flags);
3218 }
3219
3220 static int ocfs2_make_clusters_writable(struct super_block *sb,
3221                                         struct ocfs2_cow_context *context,
3222                                         u32 cpos, u32 p_cluster,
3223                                         u32 num_clusters, unsigned int e_flags)
3224 {
3225         int ret, delete, index, credits =  0;
3226         u32 new_bit, new_len, orig_num_clusters;
3227         unsigned int set_len;
3228         struct ocfs2_super *osb = OCFS2_SB(sb);
3229         handle_t *handle;
3230         struct buffer_head *ref_leaf_bh = NULL;
3231         struct ocfs2_caching_info *ref_ci = &context->ref_tree->rf_ci;
3232         struct ocfs2_refcount_rec rec;
3233
3234         trace_ocfs2_make_clusters_writable(cpos, p_cluster,
3235                                            num_clusters, e_flags);
3236
3237         ret = ocfs2_lock_refcount_allocators(sb, p_cluster, num_clusters,
3238                                              &context->data_et,
3239                                              ref_ci,
3240                                              context->ref_root_bh,
3241                                              &context->meta_ac,
3242                                              &context->data_ac, &credits);
3243         if (ret) {
3244                 mlog_errno(ret);
3245                 return ret;
3246         }
3247
3248         if (context->post_refcount)
3249                 credits += context->post_refcount->credits;
3250
3251         credits += context->extra_credits;
3252         handle = ocfs2_start_trans(osb, credits);
3253         if (IS_ERR(handle)) {
3254                 ret = PTR_ERR(handle);
3255                 mlog_errno(ret);
3256                 goto out;
3257         }
3258
3259         orig_num_clusters = num_clusters;
3260
3261         while (num_clusters) {
3262                 ret = ocfs2_get_refcount_rec(ref_ci, context->ref_root_bh,
3263                                              p_cluster, num_clusters,
3264                                              &rec, &index, &ref_leaf_bh);
3265                 if (ret) {
3266                         mlog_errno(ret);
3267                         goto out_commit;
3268                 }
3269
3270                 BUG_ON(!rec.r_refcount);
3271                 set_len = min((u64)p_cluster + num_clusters,
3272                               le64_to_cpu(rec.r_cpos) +
3273                               le32_to_cpu(rec.r_clusters)) - p_cluster;
3274
3275                 /*
3276                  * There are many different situation here.
3277                  * 1. If refcount == 1, remove the flag and don't COW.
3278                  * 2. If refcount > 1, allocate clusters.
3279                  *    Here we may not allocate r_len once at a time, so continue
3280                  *    until we reach num_clusters.
3281                  */
3282                 if (le32_to_cpu(rec.r_refcount) == 1) {
3283                         delete = 0;
3284                         ret = ocfs2_clear_ext_refcount(handle,
3285                                                        &context->data_et,
3286                                                        cpos, p_cluster,
3287                                                        set_len, e_flags,
3288                                                        context->meta_ac,
3289                                                        &context->dealloc);
3290                         if (ret) {
3291                                 mlog_errno(ret);
3292                                 goto out_commit;
3293                         }
3294                 } else {
3295                         delete = 1;
3296
3297                         ret = __ocfs2_claim_clusters(handle,
3298                                                      context->data_ac,
3299                                                      1, set_len,
3300                                                      &new_bit, &new_len);
3301                         if (ret) {
3302                                 mlog_errno(ret);
3303                                 goto out_commit;
3304                         }
3305
3306                         ret = ocfs2_replace_clusters(handle, context,
3307                                                      cpos, p_cluster, new_bit,
3308                                                      new_len, e_flags);
3309                         if (ret) {
3310                                 mlog_errno(ret);
3311                                 goto out_commit;
3312                         }
3313                         set_len = new_len;
3314                 }
3315
3316                 ret = __ocfs2_decrease_refcount(handle, ref_ci,
3317                                                 context->ref_root_bh,
3318                                                 p_cluster, set_len,
3319                                                 context->meta_ac,
3320                                                 &context->dealloc, delete);
3321                 if (ret) {
3322                         mlog_errno(ret);
3323                         goto out_commit;
3324                 }
3325
3326                 cpos += set_len;
3327                 p_cluster += set_len;
3328                 num_clusters -= set_len;
3329                 brelse(ref_leaf_bh);
3330                 ref_leaf_bh = NULL;
3331         }
3332
3333         /* handle any post_cow action. */
3334         if (context->post_refcount && context->post_refcount->func) {
3335                 ret = context->post_refcount->func(context->inode, handle,
3336                                                 context->post_refcount->para);
3337                 if (ret) {
3338                         mlog_errno(ret);
3339                         goto out_commit;
3340                 }
3341         }
3342
3343         /*
3344          * Here we should write the new page out first if we are
3345          * in write-back mode.
3346          */
3347         if (context->get_clusters == ocfs2_di_get_clusters) {
3348                 ret = ocfs2_cow_sync_writeback(sb, context->inode, cpos,
3349                                                orig_num_clusters);
3350                 if (ret)
3351                         mlog_errno(ret);
3352         }
3353
3354 out_commit:
3355         ocfs2_commit_trans(osb, handle);
3356
3357 out:
3358         if (context->data_ac) {
3359                 ocfs2_free_alloc_context(context->data_ac);
3360                 context->data_ac = NULL;
3361         }
3362         if (context->meta_ac) {
3363                 ocfs2_free_alloc_context(context->meta_ac);
3364                 context->meta_ac = NULL;
3365         }
3366         brelse(ref_leaf_bh);
3367
3368         return ret;
3369 }
3370
3371 static int ocfs2_replace_cow(struct ocfs2_cow_context *context)
3372 {
3373         int ret = 0;
3374         struct inode *inode = context->inode;
3375         u32 cow_start = context->cow_start, cow_len = context->cow_len;
3376         u32 p_cluster, num_clusters;
3377         unsigned int ext_flags;
3378         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
3379
3380         if (!ocfs2_refcount_tree(OCFS2_SB(inode->i_sb))) {
3381                 ocfs2_error(inode->i_sb, "Inode %lu want to use refcount "
3382                             "tree, but the feature bit is not set in the "
3383                             "super block.", inode->i_ino);
3384                 return -EROFS;
3385         }
3386
3387         ocfs2_init_dealloc_ctxt(&context->dealloc);
3388
3389         while (cow_len) {
3390                 ret = context->get_clusters(context, cow_start, &p_cluster,
3391                                             &num_clusters, &ext_flags);
3392                 if (ret) {
3393                         mlog_errno(ret);
3394                         break;
3395                 }
3396
3397                 BUG_ON(!(ext_flags & OCFS2_EXT_REFCOUNTED));
3398
3399                 if (cow_len < num_clusters)
3400                         num_clusters = cow_len;
3401
3402                 ret = ocfs2_make_clusters_writable(inode->i_sb, context,
3403                                                    cow_start, p_cluster,
3404                                                    num_clusters, ext_flags);
3405                 if (ret) {
3406                         mlog_errno(ret);
3407                         break;
3408                 }
3409
3410                 cow_len -= num_clusters;
3411                 cow_start += num_clusters;
3412         }
3413
3414         if (ocfs2_dealloc_has_cluster(&context->dealloc)) {
3415                 ocfs2_schedule_truncate_log_flush(osb, 1);
3416                 ocfs2_run_deallocs(osb, &context->dealloc);
3417         }
3418
3419         return ret;
3420 }
3421
3422 /*
3423  * Starting at cpos, try to CoW write_len clusters.  Don't CoW
3424  * past max_cpos.  This will stop when it runs into a hole or an
3425  * unrefcounted extent.
3426  */
3427 static int ocfs2_refcount_cow_hunk(struct inode *inode,
3428                                    struct buffer_head *di_bh,
3429                                    u32 cpos, u32 write_len, u32 max_cpos)
3430 {
3431         int ret;
3432         u32 cow_start = 0, cow_len = 0;
3433         struct ocfs2_inode_info *oi = OCFS2_I(inode);
3434         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
3435         struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
3436         struct buffer_head *ref_root_bh = NULL;
3437         struct ocfs2_refcount_tree *ref_tree;
3438         struct ocfs2_cow_context *context = NULL;
3439
3440         BUG_ON(!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL));
3441
3442         ret = ocfs2_refcount_cal_cow_clusters(inode, &di->id2.i_list,
3443                                               cpos, write_len, max_cpos,
3444                                               &cow_start, &cow_len);
3445         if (ret) {
3446                 mlog_errno(ret);
3447                 goto out;
3448         }
3449
3450         trace_ocfs2_refcount_cow_hunk(OCFS2_I(inode)->ip_blkno,
3451                                       cpos, write_len, max_cpos,
3452                                       cow_start, cow_len);
3453
3454         BUG_ON(cow_len == 0);
3455
3456         context = kzalloc(sizeof(struct ocfs2_cow_context), GFP_NOFS);
3457         if (!context) {
3458                 ret = -ENOMEM;
3459                 mlog_errno(ret);
3460                 goto out;
3461         }
3462
3463         ret = ocfs2_lock_refcount_tree(osb, le64_to_cpu(di->i_refcount_loc),
3464                                        1, &ref_tree, &ref_root_bh);
3465         if (ret) {
3466                 mlog_errno(ret);
3467                 goto out;
3468         }
3469
3470         context->inode = inode;
3471         context->cow_start = cow_start;
3472         context->cow_len = cow_len;
3473         context->ref_tree = ref_tree;
3474         context->ref_root_bh = ref_root_bh;
3475         context->cow_duplicate_clusters = ocfs2_duplicate_clusters_by_page;
3476         context->get_clusters = ocfs2_di_get_clusters;
3477
3478         ocfs2_init_dinode_extent_tree(&context->data_et,
3479                                       INODE_CACHE(inode), di_bh);
3480
3481         ret = ocfs2_replace_cow(context);
3482         if (ret)
3483                 mlog_errno(ret);
3484
3485         /*
3486          * truncate the extent map here since no matter whether we meet with
3487          * any error during the action, we shouldn't trust cached extent map
3488          * any more.
3489          */
3490         ocfs2_extent_map_trunc(inode, cow_start);
3491
3492         ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
3493         brelse(ref_root_bh);
3494 out:
3495         kfree(context);
3496         return ret;
3497 }
3498
3499 /*
3500  * CoW any and all clusters between cpos and cpos+write_len.
3501  * Don't CoW past max_cpos.  If this returns successfully, all
3502  * clusters between cpos and cpos+write_len are safe to modify.
3503  */
3504 int ocfs2_refcount_cow(struct inode *inode,
3505                        struct buffer_head *di_bh,
3506                        u32 cpos, u32 write_len, u32 max_cpos)
3507 {
3508         int ret = 0;
3509         u32 p_cluster, num_clusters;
3510         unsigned int ext_flags;
3511
3512         while (write_len) {
3513                 ret = ocfs2_get_clusters(inode, cpos, &p_cluster,
3514                                          &num_clusters, &ext_flags);
3515                 if (ret) {
3516                         mlog_errno(ret);
3517                         break;
3518                 }
3519
3520                 if (write_len < num_clusters)
3521                         num_clusters = write_len;
3522
3523                 if (ext_flags & OCFS2_EXT_REFCOUNTED) {
3524                         ret = ocfs2_refcount_cow_hunk(inode, di_bh, cpos,
3525                                                       num_clusters, max_cpos);
3526                         if (ret) {
3527                                 mlog_errno(ret);
3528                                 break;
3529                         }
3530                 }
3531
3532                 write_len -= num_clusters;
3533                 cpos += num_clusters;
3534         }
3535
3536         return ret;
3537 }
3538
3539 static int ocfs2_xattr_value_get_clusters(struct ocfs2_cow_context *context,
3540                                           u32 v_cluster, u32 *p_cluster,
3541                                           u32 *num_clusters,
3542                                           unsigned int *extent_flags)
3543 {
3544         struct inode *inode = context->inode;
3545         struct ocfs2_xattr_value_root *xv = context->cow_object;
3546
3547         return ocfs2_xattr_get_clusters(inode, v_cluster, p_cluster,
3548                                         num_clusters, &xv->xr_list,
3549                                         extent_flags);
3550 }
3551
3552 /*
3553  * Given a xattr value root, calculate the most meta/credits we need for
3554  * refcount tree change if we truncate it to 0.
3555  */
3556 int ocfs2_refcounted_xattr_delete_need(struct inode *inode,
3557                                        struct ocfs2_caching_info *ref_ci,
3558                                        struct buffer_head *ref_root_bh,
3559                                        struct ocfs2_xattr_value_root *xv,
3560                                        int *meta_add, int *credits)
3561 {
3562         int ret = 0, index, ref_blocks = 0;
3563         u32 p_cluster, num_clusters;
3564         u32 cpos = 0, clusters = le32_to_cpu(xv->xr_clusters);
3565         struct ocfs2_refcount_block *rb;
3566         struct ocfs2_refcount_rec rec;
3567         struct buffer_head *ref_leaf_bh = NULL;
3568
3569         while (cpos < clusters) {
3570                 ret = ocfs2_xattr_get_clusters(inode, cpos, &p_cluster,
3571                                                &num_clusters, &xv->xr_list,
3572                                                NULL);
3573                 if (ret) {
3574                         mlog_errno(ret);
3575                         goto out;
3576                 }
3577
3578                 cpos += num_clusters;
3579
3580                 while (num_clusters) {
3581                         ret = ocfs2_get_refcount_rec(ref_ci, ref_root_bh,
3582                                                      p_cluster, num_clusters,
3583                                                      &rec, &index,
3584                                                      &ref_leaf_bh);
3585                         if (ret) {
3586                                 mlog_errno(ret);
3587                                 goto out;
3588                         }
3589
3590                         BUG_ON(!rec.r_refcount);
3591
3592                         rb = (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
3593
3594                         /*
3595                          * We really don't know whether the other clusters is in
3596                          * this refcount block or not, so just take the worst
3597                          * case that all the clusters are in this block and each
3598                          * one will split a refcount rec, so totally we need
3599                          * clusters * 2 new refcount rec.
3600                          */
3601                         if (le16_to_cpu(rb->rf_records.rl_used) + clusters * 2 >
3602                             le16_to_cpu(rb->rf_records.rl_count))
3603                                 ref_blocks++;
3604
3605                         *credits += 1;
3606                         brelse(ref_leaf_bh);
3607                         ref_leaf_bh = NULL;
3608
3609                         if (num_clusters <= le32_to_cpu(rec.r_clusters))
3610                                 break;
3611                         else
3612                                 num_clusters -= le32_to_cpu(rec.r_clusters);
3613                         p_cluster += num_clusters;
3614                 }
3615         }
3616
3617         *meta_add += ref_blocks;
3618         if (!ref_blocks)
3619                 goto out;
3620
3621         rb = (struct ocfs2_refcount_block *)ref_root_bh->b_data;
3622         if (le32_to_cpu(rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL)
3623                 *credits += OCFS2_EXPAND_REFCOUNT_TREE_CREDITS;
3624         else {
3625                 struct ocfs2_extent_tree et;
3626
3627                 ocfs2_init_refcount_extent_tree(&et, ref_ci, ref_root_bh);
3628                 *credits += ocfs2_calc_extend_credits(inode->i_sb,
3629                                                       et.et_root_el);
3630         }
3631
3632 out:
3633         brelse(ref_leaf_bh);
3634         return ret;
3635 }
3636
3637 /*
3638  * Do CoW for xattr.
3639  */
3640 int ocfs2_refcount_cow_xattr(struct inode *inode,
3641                              struct ocfs2_dinode *di,
3642                              struct ocfs2_xattr_value_buf *vb,
3643                              struct ocfs2_refcount_tree *ref_tree,
3644                              struct buffer_head *ref_root_bh,
3645                              u32 cpos, u32 write_len,
3646                              struct ocfs2_post_refcount *post)
3647 {
3648         int ret;
3649         struct ocfs2_xattr_value_root *xv = vb->vb_xv;
3650         struct ocfs2_inode_info *oi = OCFS2_I(inode);
3651         struct ocfs2_cow_context *context = NULL;
3652         u32 cow_start, cow_len;
3653
3654         BUG_ON(!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL));
3655
3656         ret = ocfs2_refcount_cal_cow_clusters(inode, &xv->xr_list,
3657                                               cpos, write_len, UINT_MAX,
3658                                               &cow_start, &cow_len);
3659         if (ret) {
3660                 mlog_errno(ret);
3661                 goto out;
3662         }
3663
3664         BUG_ON(cow_len == 0);
3665
3666         context = kzalloc(sizeof(struct ocfs2_cow_context), GFP_NOFS);
3667         if (!context) {
3668                 ret = -ENOMEM;
3669                 mlog_errno(ret);
3670                 goto out;
3671         }
3672
3673         context->inode = inode;
3674         context->cow_start = cow_start;
3675         context->cow_len = cow_len;
3676         context->ref_tree = ref_tree;
3677         context->ref_root_bh = ref_root_bh;
3678         context->cow_object = xv;
3679
3680         context->cow_duplicate_clusters = ocfs2_duplicate_clusters_by_jbd;
3681         /* We need the extra credits for duplicate_clusters by jbd. */
3682         context->extra_credits =
3683                 ocfs2_clusters_to_blocks(inode->i_sb, 1) * cow_len;
3684         context->get_clusters = ocfs2_xattr_value_get_clusters;
3685         context->post_refcount = post;
3686
3687         ocfs2_init_xattr_value_extent_tree(&context->data_et,
3688                                            INODE_CACHE(inode), vb);
3689
3690         ret = ocfs2_replace_cow(context);
3691         if (ret)
3692                 mlog_errno(ret);
3693
3694 out:
3695         kfree(context);
3696         return ret;
3697 }
3698
3699 /*
3700  * Insert a new extent into refcount tree and mark a extent rec
3701  * as refcounted in the dinode tree.
3702  */
3703 int ocfs2_add_refcount_flag(struct inode *inode,
3704                             struct ocfs2_extent_tree *data_et,
3705                             struct ocfs2_caching_info *ref_ci,
3706                             struct buffer_head *ref_root_bh,
3707                             u32 cpos, u32 p_cluster, u32 num_clusters,
3708                             struct ocfs2_cached_dealloc_ctxt *dealloc,
3709                             struct ocfs2_post_refcount *post)
3710 {
3711         int ret;
3712         handle_t *handle;
3713         int credits = 1, ref_blocks = 0;
3714         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
3715         struct ocfs2_alloc_context *meta_ac = NULL;
3716
3717         ret = ocfs2_calc_refcount_meta_credits(inode->i_sb,
3718                                                ref_ci, ref_root_bh,
3719                                                p_cluster, num_clusters,
3720                                                &ref_blocks, &credits);
3721         if (ret) {
3722                 mlog_errno(ret);
3723                 goto out;
3724         }
3725
3726         trace_ocfs2_add_refcount_flag(ref_blocks, credits);
3727
3728         if (ref_blocks) {
3729                 ret = ocfs2_reserve_new_metadata_blocks(OCFS2_SB(inode->i_sb),
3730                                                         ref_blocks, &meta_ac);
3731                 if (ret) {
3732                         mlog_errno(ret);
3733                         goto out;
3734                 }
3735         }
3736
3737         if (post)
3738                 credits += post->credits;
3739
3740         handle = ocfs2_start_trans(osb, credits);
3741         if (IS_ERR(handle)) {
3742                 ret = PTR_ERR(handle);
3743                 mlog_errno(ret);
3744                 goto out;
3745         }
3746
3747         ret = ocfs2_mark_extent_refcounted(inode, data_et, handle,
3748                                            cpos, num_clusters, p_cluster,
3749                                            meta_ac, dealloc);
3750         if (ret) {
3751                 mlog_errno(ret);
3752                 goto out_commit;
3753         }
3754
3755         ret = __ocfs2_increase_refcount(handle, ref_ci, ref_root_bh,
3756                                         p_cluster, num_clusters, 0,
3757                                         meta_ac, dealloc);
3758         if (ret) {
3759                 mlog_errno(ret);
3760                 goto out_commit;
3761         }
3762
3763         if (post && post->func) {
3764                 ret = post->func(inode, handle, post->para);
3765                 if (ret)
3766                         mlog_errno(ret);
3767         }
3768
3769 out_commit:
3770         ocfs2_commit_trans(osb, handle);
3771 out:
3772         if (meta_ac)
3773                 ocfs2_free_alloc_context(meta_ac);
3774         return ret;
3775 }
3776
3777 static int ocfs2_change_ctime(struct inode *inode,
3778                               struct buffer_head *di_bh)
3779 {
3780         int ret;
3781         handle_t *handle;
3782         struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
3783
3784         handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb),
3785                                    OCFS2_INODE_UPDATE_CREDITS);
3786         if (IS_ERR(handle)) {
3787                 ret = PTR_ERR(handle);
3788                 mlog_errno(ret);
3789                 goto out;
3790         }
3791
3792         ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
3793                                       OCFS2_JOURNAL_ACCESS_WRITE);
3794         if (ret) {
3795                 mlog_errno(ret);
3796                 goto out_commit;
3797         }
3798
3799         inode->i_ctime = CURRENT_TIME;
3800         di->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
3801         di->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
3802
3803         ocfs2_journal_dirty(handle, di_bh);
3804
3805 out_commit:
3806         ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
3807 out:
3808         return ret;
3809 }
3810
3811 static int ocfs2_attach_refcount_tree(struct inode *inode,
3812                                       struct buffer_head *di_bh)
3813 {
3814         int ret, data_changed = 0;
3815         struct buffer_head *ref_root_bh = NULL;
3816         struct ocfs2_inode_info *oi = OCFS2_I(inode);
3817         struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
3818         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
3819         struct ocfs2_refcount_tree *ref_tree;
3820         unsigned int ext_flags;
3821         loff_t size;
3822         u32 cpos, num_clusters, clusters, p_cluster;
3823         struct ocfs2_cached_dealloc_ctxt dealloc;
3824         struct ocfs2_extent_tree di_et;
3825
3826         ocfs2_init_dealloc_ctxt(&dealloc);
3827
3828         if (!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL)) {
3829                 ret = ocfs2_create_refcount_tree(inode, di_bh);
3830                 if (ret) {
3831                         mlog_errno(ret);
3832                         goto out;
3833                 }
3834         }
3835
3836         BUG_ON(!di->i_refcount_loc);
3837         ret = ocfs2_lock_refcount_tree(osb,
3838                                        le64_to_cpu(di->i_refcount_loc), 1,
3839                                        &ref_tree, &ref_root_bh);
3840         if (ret) {
3841                 mlog_errno(ret);
3842                 goto out;
3843         }
3844
3845         if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
3846                 goto attach_xattr;
3847
3848         ocfs2_init_dinode_extent_tree(&di_et, INODE_CACHE(inode), di_bh);
3849
3850         size = i_size_read(inode);
3851         clusters = ocfs2_clusters_for_bytes(inode->i_sb, size);
3852
3853         cpos = 0;
3854         while (cpos < clusters) {
3855                 ret = ocfs2_get_clusters(inode, cpos, &p_cluster,
3856                                          &num_clusters, &ext_flags);
3857                 if (ret) {
3858                         mlog_errno(ret);
3859                         goto unlock;
3860                 }
3861                 if (p_cluster && !(ext_flags & OCFS2_EXT_REFCOUNTED)) {
3862                         ret = ocfs2_add_refcount_flag(inode, &di_et,
3863                                                       &ref_tree->rf_ci,
3864                                                       ref_root_bh, cpos,
3865                                                       p_cluster, num_clusters,
3866                                                       &dealloc, NULL);
3867                         if (ret) {
3868                                 mlog_errno(ret);
3869                                 goto unlock;
3870                         }
3871
3872                         data_changed = 1;
3873                 }
3874                 cpos += num_clusters;
3875         }
3876
3877 attach_xattr:
3878         if (oi->ip_dyn_features & OCFS2_HAS_XATTR_FL) {
3879                 ret = ocfs2_xattr_attach_refcount_tree(inode, di_bh,
3880                                                        &ref_tree->rf_ci,
3881                                                        ref_root_bh,
3882                                                        &dealloc);
3883                 if (ret) {
3884                         mlog_errno(ret);
3885                         goto unlock;
3886                 }
3887         }
3888
3889         if (data_changed) {
3890                 ret = ocfs2_change_ctime(inode, di_bh);
3891                 if (ret)
3892                         mlog_errno(ret);
3893         }
3894
3895 unlock:
3896         ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
3897         brelse(ref_root_bh);
3898
3899         if (!ret && ocfs2_dealloc_has_cluster(&dealloc)) {
3900                 ocfs2_schedule_truncate_log_flush(osb, 1);
3901                 ocfs2_run_deallocs(osb, &dealloc);
3902         }
3903 out:
3904         /*
3905          * Empty the extent map so that we may get the right extent
3906          * record from the disk.
3907          */
3908         ocfs2_extent_map_trunc(inode, 0);
3909
3910         return ret;
3911 }
3912
3913 static int ocfs2_add_refcounted_extent(struct inode *inode,
3914                                    struct ocfs2_extent_tree *et,
3915                                    struct ocfs2_caching_info *ref_ci,
3916                                    struct buffer_head *ref_root_bh,
3917                                    u32 cpos, u32 p_cluster, u32 num_clusters,
3918                                    unsigned int ext_flags,
3919                                    struct ocfs2_cached_dealloc_ctxt *dealloc)
3920 {
3921         int ret;
3922         handle_t *handle;
3923         int credits = 0;
3924         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
3925         struct ocfs2_alloc_context *meta_ac = NULL;
3926
3927         ret = ocfs2_lock_refcount_allocators(inode->i_sb,
3928                                              p_cluster, num_clusters,
3929                                              et, ref_ci,
3930                                              ref_root_bh, &meta_ac,
3931                                              NULL, &credits);
3932         if (ret) {
3933                 mlog_errno(ret);
3934                 goto out;
3935         }
3936
3937         handle = ocfs2_start_trans(osb, credits);
3938         if (IS_ERR(handle)) {
3939                 ret = PTR_ERR(handle);
3940                 mlog_errno(ret);
3941                 goto out;
3942         }
3943
3944         ret = ocfs2_insert_extent(handle, et, cpos,
3945                         ocfs2_clusters_to_blocks(inode->i_sb, p_cluster),
3946                         num_clusters, ext_flags, meta_ac);
3947         if (ret) {
3948                 mlog_errno(ret);
3949                 goto out_commit;
3950         }
3951
3952         ret = ocfs2_increase_refcount(handle, ref_ci, ref_root_bh,
3953                                       p_cluster, num_clusters,
3954                                       meta_ac, dealloc);
3955         if (ret)
3956                 mlog_errno(ret);
3957
3958 out_commit:
3959         ocfs2_commit_trans(osb, handle);
3960 out:
3961         if (meta_ac)
3962                 ocfs2_free_alloc_context(meta_ac);
3963         return ret;
3964 }
3965
3966 static int ocfs2_duplicate_inline_data(struct inode *s_inode,
3967                                        struct buffer_head *s_bh,
3968                                        struct inode *t_inode,
3969                                        struct buffer_head *t_bh)
3970 {
3971         int ret;
3972         handle_t *handle;
3973         struct ocfs2_super *osb = OCFS2_SB(s_inode->i_sb);
3974         struct ocfs2_dinode *s_di = (struct ocfs2_dinode *)s_bh->b_data;
3975         struct ocfs2_dinode *t_di = (struct ocfs2_dinode *)t_bh->b_data;
3976
3977         BUG_ON(!(OCFS2_I(s_inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL));
3978
3979         handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
3980         if (IS_ERR(handle)) {
3981                 ret = PTR_ERR(handle);
3982                 mlog_errno(ret);
3983                 goto out;
3984         }
3985
3986         ret = ocfs2_journal_access_di(handle, INODE_CACHE(t_inode), t_bh,
3987                                       OCFS2_JOURNAL_ACCESS_WRITE);
3988         if (ret) {
3989                 mlog_errno(ret);
3990                 goto out_commit;
3991         }
3992
3993         t_di->id2.i_data.id_count = s_di->id2.i_data.id_count;
3994         memcpy(t_di->id2.i_data.id_data, s_di->id2.i_data.id_data,
3995                le16_to_cpu(s_di->id2.i_data.id_count));
3996         spin_lock(&OCFS2_I(t_inode)->ip_lock);
3997         OCFS2_I(t_inode)->ip_dyn_features |= OCFS2_INLINE_DATA_FL;
3998         t_di->i_dyn_features = cpu_to_le16(OCFS2_I(t_inode)->ip_dyn_features);
3999         spin_unlock(&OCFS2_I(t_inode)->ip_lock);
4000
4001         ocfs2_journal_dirty(handle, t_bh);
4002
4003 out_commit:
4004         ocfs2_commit_trans(osb, handle);
4005 out:
4006         return ret;
4007 }
4008
4009 static int ocfs2_duplicate_extent_list(struct inode *s_inode,
4010                                 struct inode *t_inode,
4011                                 struct buffer_head *t_bh,
4012                                 struct ocfs2_caching_info *ref_ci,
4013                                 struct buffer_head *ref_root_bh,
4014                                 struct ocfs2_cached_dealloc_ctxt *dealloc)
4015 {
4016         int ret = 0;
4017         u32 p_cluster, num_clusters, clusters, cpos;
4018         loff_t size;
4019         unsigned int ext_flags;
4020         struct ocfs2_extent_tree et;
4021
4022         ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(t_inode), t_bh);
4023
4024         size = i_size_read(s_inode);
4025         clusters = ocfs2_clusters_for_bytes(s_inode->i_sb, size);
4026
4027         cpos = 0;
4028         while (cpos < clusters) {
4029                 ret = ocfs2_get_clusters(s_inode, cpos, &p_cluster,
4030                                          &num_clusters, &ext_flags);
4031                 if (ret) {
4032                         mlog_errno(ret);
4033                         goto out;
4034                 }
4035                 if (p_cluster) {
4036                         ret = ocfs2_add_refcounted_extent(t_inode, &et,
4037                                                           ref_ci, ref_root_bh,
4038                                                           cpos, p_cluster,
4039                                                           num_clusters,
4040                                                           ext_flags,
4041                                                           dealloc);
4042                         if (ret) {
4043                                 mlog_errno(ret);
4044                                 goto out;
4045                         }
4046                 }
4047
4048                 cpos += num_clusters;
4049         }
4050
4051 out:
4052         return ret;
4053 }
4054
4055 /*
4056  * change the new file's attributes to the src.
4057  *
4058  * reflink creates a snapshot of a file, that means the attributes
4059  * must be identical except for three exceptions - nlink, ino, and ctime.
4060  */
4061 static int ocfs2_complete_reflink(struct inode *s_inode,
4062                                   struct buffer_head *s_bh,
4063                                   struct inode *t_inode,
4064                                   struct buffer_head *t_bh,
4065                                   bool preserve)
4066 {
4067         int ret;
4068         handle_t *handle;
4069         struct ocfs2_dinode *s_di = (struct ocfs2_dinode *)s_bh->b_data;
4070         struct ocfs2_dinode *di = (struct ocfs2_dinode *)t_bh->b_data;
4071         loff_t size = i_size_read(s_inode);
4072
4073         handle = ocfs2_start_trans(OCFS2_SB(t_inode->i_sb),
4074                                    OCFS2_INODE_UPDATE_CREDITS);
4075         if (IS_ERR(handle)) {
4076                 ret = PTR_ERR(handle);
4077                 mlog_errno(ret);
4078                 return ret;
4079         }
4080
4081         ret = ocfs2_journal_access_di(handle, INODE_CACHE(t_inode), t_bh,
4082                                       OCFS2_JOURNAL_ACCESS_WRITE);
4083         if (ret) {
4084                 mlog_errno(ret);
4085                 goto out_commit;
4086         }
4087
4088         spin_lock(&OCFS2_I(t_inode)->ip_lock);
4089         OCFS2_I(t_inode)->ip_clusters = OCFS2_I(s_inode)->ip_clusters;
4090         OCFS2_I(t_inode)->ip_attr = OCFS2_I(s_inode)->ip_attr;
4091         OCFS2_I(t_inode)->ip_dyn_features = OCFS2_I(s_inode)->ip_dyn_features;
4092         spin_unlock(&OCFS2_I(t_inode)->ip_lock);
4093         i_size_write(t_inode, size);
4094         t_inode->i_blocks = s_inode->i_blocks;
4095
4096         di->i_xattr_inline_size = s_di->i_xattr_inline_size;
4097         di->i_clusters = s_di->i_clusters;
4098         di->i_size = s_di->i_size;
4099         di->i_dyn_features = s_di->i_dyn_features;
4100         di->i_attr = s_di->i_attr;
4101
4102         if (preserve) {
4103                 t_inode->i_uid = s_inode->i_uid;
4104                 t_inode->i_gid = s_inode->i_gid;
4105                 t_inode->i_mode = s_inode->i_mode;
4106                 di->i_uid = s_di->i_uid;
4107                 di->i_gid = s_di->i_gid;
4108                 di->i_mode = s_di->i_mode;
4109
4110                 /*
4111                  * update time.
4112                  * we want mtime to appear identical to the source and
4113                  * update ctime.
4114                  */
4115                 t_inode->i_ctime = CURRENT_TIME;
4116
4117                 di->i_ctime = cpu_to_le64(t_inode->i_ctime.tv_sec);
4118                 di->i_ctime_nsec = cpu_to_le32(t_inode->i_ctime.tv_nsec);
4119
4120                 t_inode->i_mtime = s_inode->i_mtime;
4121                 di->i_mtime = s_di->i_mtime;
4122                 di->i_mtime_nsec = s_di->i_mtime_nsec;
4123         }
4124
4125         ocfs2_journal_dirty(handle, t_bh);
4126
4127 out_commit:
4128         ocfs2_commit_trans(OCFS2_SB(t_inode->i_sb), handle);
4129         return ret;
4130 }
4131
4132 static int ocfs2_create_reflink_node(struct inode *s_inode,
4133                                      struct buffer_head *s_bh,
4134                                      struct inode *t_inode,
4135                                      struct buffer_head *t_bh,
4136                                      bool preserve)
4137 {
4138         int ret;
4139         struct buffer_head *ref_root_bh = NULL;
4140         struct ocfs2_cached_dealloc_ctxt dealloc;
4141         struct ocfs2_super *osb = OCFS2_SB(s_inode->i_sb);
4142         struct ocfs2_refcount_block *rb;
4143         struct ocfs2_dinode *di = (struct ocfs2_dinode *)s_bh->b_data;
4144         struct ocfs2_refcount_tree *ref_tree;
4145
4146         ocfs2_init_dealloc_ctxt(&dealloc);
4147
4148         ret = ocfs2_set_refcount_tree(t_inode, t_bh,
4149                                       le64_to_cpu(di->i_refcount_loc));
4150         if (ret) {
4151                 mlog_errno(ret);
4152                 goto out;
4153         }
4154
4155         if (OCFS2_I(s_inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
4156                 ret = ocfs2_duplicate_inline_data(s_inode, s_bh,
4157                                                   t_inode, t_bh);
4158                 if (ret)
4159                         mlog_errno(ret);
4160                 goto out;
4161         }
4162
4163         ret = ocfs2_lock_refcount_tree(osb, le64_to_cpu(di->i_refcount_loc),
4164                                        1, &ref_tree, &ref_root_bh);
4165         if (ret) {
4166                 mlog_errno(ret);
4167                 goto out;
4168         }
4169         rb = (struct ocfs2_refcount_block *)ref_root_bh->b_data;
4170
4171         ret = ocfs2_duplicate_extent_list(s_inode, t_inode, t_bh,
4172                                           &ref_tree->rf_ci, ref_root_bh,
4173                                           &dealloc);
4174         if (ret) {
4175                 mlog_errno(ret);
4176                 goto out_unlock_refcount;
4177         }
4178
4179 out_unlock_refcount:
4180         ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
4181         brelse(ref_root_bh);
4182 out:
4183         if (ocfs2_dealloc_has_cluster(&dealloc)) {
4184                 ocfs2_schedule_truncate_log_flush(osb, 1);
4185                 ocfs2_run_deallocs(osb, &dealloc);
4186         }
4187
4188         return ret;
4189 }
4190
4191 static int __ocfs2_reflink(struct dentry *old_dentry,
4192                            struct buffer_head *old_bh,
4193                            struct inode *new_inode,
4194                            bool preserve)
4195 {
4196         int ret;
4197         struct inode *inode = d_inode(old_dentry);
4198         struct buffer_head *new_bh = NULL;
4199
4200         if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE) {
4201                 ret = -EINVAL;
4202                 mlog_errno(ret);
4203                 goto out;
4204         }
4205
4206         ret = filemap_fdatawrite(inode->i_mapping);
4207         if (ret) {
4208                 mlog_errno(ret);
4209                 goto out;
4210         }
4211
4212         ret = ocfs2_attach_refcount_tree(inode, old_bh);
4213         if (ret) {
4214                 mlog_errno(ret);
4215                 goto out;
4216         }
4217
4218         mutex_lock_nested(&new_inode->i_mutex, I_MUTEX_CHILD);
4219         ret = ocfs2_inode_lock_nested(new_inode, &new_bh, 1,
4220                                       OI_LS_REFLINK_TARGET);
4221         if (ret) {
4222                 mlog_errno(ret);
4223                 goto out_unlock;
4224         }
4225
4226         ret = ocfs2_create_reflink_node(inode, old_bh,
4227                                         new_inode, new_bh, preserve);
4228         if (ret) {
4229                 mlog_errno(ret);
4230                 goto inode_unlock;
4231         }
4232
4233         if (OCFS2_I(inode)->ip_dyn_features & OCFS2_HAS_XATTR_FL) {
4234                 ret = ocfs2_reflink_xattrs(inode, old_bh,
4235                                            new_inode, new_bh,
4236                                            preserve);
4237                 if (ret) {
4238                         mlog_errno(ret);
4239                         goto inode_unlock;
4240                 }
4241         }
4242
4243         ret = ocfs2_complete_reflink(inode, old_bh,
4244                                      new_inode, new_bh, preserve);
4245         if (ret)
4246                 mlog_errno(ret);
4247
4248 inode_unlock:
4249         ocfs2_inode_unlock(new_inode, 1);
4250         brelse(new_bh);
4251 out_unlock:
4252         mutex_unlock(&new_inode->i_mutex);
4253 out:
4254         if (!ret) {
4255                 ret = filemap_fdatawait(inode->i_mapping);
4256                 if (ret)
4257                         mlog_errno(ret);
4258         }
4259         return ret;
4260 }
4261
4262 static int ocfs2_reflink(struct dentry *old_dentry, struct inode *dir,
4263                          struct dentry *new_dentry, bool preserve)
4264 {
4265         int error;
4266         struct inode *inode = d_inode(old_dentry);
4267         struct buffer_head *old_bh = NULL;
4268         struct inode *new_orphan_inode = NULL;
4269         struct posix_acl *default_acl, *acl;
4270         umode_t mode;
4271
4272         if (!ocfs2_refcount_tree(OCFS2_SB(inode->i_sb)))
4273                 return -EOPNOTSUPP;
4274
4275         mode = inode->i_mode;
4276         error = posix_acl_create(dir, &mode, &default_acl, &acl);
4277         if (error) {
4278                 mlog_errno(error);
4279                 return error;
4280         }
4281
4282         error = ocfs2_create_inode_in_orphan(dir, mode,
4283                                              &new_orphan_inode);
4284         if (error) {
4285                 mlog_errno(error);
4286                 goto out;
4287         }
4288
4289         error = ocfs2_rw_lock(inode, 1);
4290         if (error) {
4291                 mlog_errno(error);
4292                 goto out;
4293         }
4294
4295         error = ocfs2_inode_lock(inode, &old_bh, 1);
4296         if (error) {
4297                 mlog_errno(error);
4298                 ocfs2_rw_unlock(inode, 1);
4299                 goto out;
4300         }
4301
4302         down_write(&OCFS2_I(inode)->ip_xattr_sem);
4303         down_write(&OCFS2_I(inode)->ip_alloc_sem);
4304         error = __ocfs2_reflink(old_dentry, old_bh,
4305                                 new_orphan_inode, preserve);
4306         up_write(&OCFS2_I(inode)->ip_alloc_sem);
4307         up_write(&OCFS2_I(inode)->ip_xattr_sem);
4308
4309         ocfs2_inode_unlock(inode, 1);
4310         ocfs2_rw_unlock(inode, 1);
4311         brelse(old_bh);
4312
4313         if (error) {
4314                 mlog_errno(error);
4315                 goto out;
4316         }
4317
4318         /* If the security isn't preserved, we need to re-initialize them. */
4319         if (!preserve) {
4320                 error = ocfs2_init_security_and_acl(dir, new_orphan_inode,
4321                                                     &new_dentry->d_name,
4322                                                     default_acl, acl);
4323                 if (error)
4324                         mlog_errno(error);
4325         }
4326 out:
4327         if (default_acl)
4328                 posix_acl_release(default_acl);
4329         if (acl)
4330                 posix_acl_release(acl);
4331         if (!error) {
4332                 error = ocfs2_mv_orphaned_inode_to_new(dir, new_orphan_inode,
4333                                                        new_dentry);
4334                 if (error)
4335                         mlog_errno(error);
4336         }
4337
4338         if (new_orphan_inode) {
4339                 /*
4340                  * We need to open_unlock the inode no matter whether we
4341                  * succeed or not, so that other nodes can delete it later.
4342                  */
4343                 ocfs2_open_unlock(new_orphan_inode);
4344                 if (error)
4345                         iput(new_orphan_inode);
4346         }
4347
4348         return error;
4349 }
4350
4351 /*
4352  * Below here are the bits used by OCFS2_IOC_REFLINK() to fake
4353  * sys_reflink().  This will go away when vfs_reflink() exists in
4354  * fs/namei.c.
4355  */
4356
4357 /* copied from may_create in VFS. */
4358 static inline int ocfs2_may_create(struct inode *dir, struct dentry *child)
4359 {
4360         if (d_really_is_positive(child))
4361                 return -EEXIST;
4362         if (IS_DEADDIR(dir))
4363                 return -ENOENT;
4364         return inode_permission(dir, MAY_WRITE | MAY_EXEC);
4365 }
4366
4367 /**
4368  * ocfs2_vfs_reflink - Create a reference-counted link
4369  *
4370  * @old_dentry:        source dentry + inode
4371  * @dir:       directory to create the target
4372  * @new_dentry:        target dentry
4373  * @preserve:  if true, preserve all file attributes
4374  */
4375 static int ocfs2_vfs_reflink(struct dentry *old_dentry, struct inode *dir,
4376                              struct dentry *new_dentry, bool preserve)
4377 {
4378         struct inode *inode = d_inode(old_dentry);
4379         int error;
4380
4381         if (!inode)
4382                 return -ENOENT;
4383
4384         error = ocfs2_may_create(dir, new_dentry);
4385         if (error)
4386                 return error;
4387
4388         if (dir->i_sb != inode->i_sb)
4389                 return -EXDEV;
4390
4391         /*
4392          * A reflink to an append-only or immutable file cannot be created.
4393          */
4394         if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
4395                 return -EPERM;
4396
4397         /* Only regular files can be reflinked. */
4398         if (!S_ISREG(inode->i_mode))
4399                 return -EPERM;
4400
4401         /*
4402          * If the caller wants to preserve ownership, they require the
4403          * rights to do so.
4404          */
4405         if (preserve) {
4406                 if (!uid_eq(current_fsuid(), inode->i_uid) && !capable(CAP_CHOWN))
4407                         return -EPERM;
4408                 if (!in_group_p(inode->i_gid) && !capable(CAP_CHOWN))
4409                         return -EPERM;
4410         }
4411
4412         /*
4413          * If the caller is modifying any aspect of the attributes, they
4414          * are not creating a snapshot.  They need read permission on the
4415          * file.
4416          */
4417         if (!preserve) {
4418                 error = inode_permission(inode, MAY_READ);
4419                 if (error)
4420                         return error;
4421         }
4422
4423         mutex_lock(&inode->i_mutex);
4424         dquot_initialize(dir);
4425         error = ocfs2_reflink(old_dentry, dir, new_dentry, preserve);
4426         mutex_unlock(&inode->i_mutex);
4427         if (!error)
4428                 fsnotify_create(dir, new_dentry);
4429         return error;
4430 }
4431 /*
4432  * Most codes are copied from sys_linkat.
4433  */
4434 int ocfs2_reflink_ioctl(struct inode *inode,
4435                         const char __user *oldname,
4436                         const char __user *newname,
4437                         bool preserve)
4438 {
4439         struct dentry *new_dentry;
4440         struct path old_path, new_path;
4441         int error;
4442
4443         if (!ocfs2_refcount_tree(OCFS2_SB(inode->i_sb)))
4444                 return -EOPNOTSUPP;
4445
4446         error = user_path_at(AT_FDCWD, oldname, 0, &old_path);
4447         if (error) {
4448                 mlog_errno(error);
4449                 return error;
4450         }
4451
4452         new_dentry = user_path_create(AT_FDCWD, newname, &new_path, 0);
4453         error = PTR_ERR(new_dentry);
4454         if (IS_ERR(new_dentry)) {
4455                 mlog_errno(error);
4456                 goto out;
4457         }
4458
4459         error = -EXDEV;
4460         if (old_path.mnt != new_path.mnt) {
4461                 mlog_errno(error);
4462                 goto out_dput;
4463         }
4464
4465         error = ocfs2_vfs_reflink(old_path.dentry,
4466                                   d_inode(new_path.dentry),
4467                                   new_dentry, preserve);
4468 out_dput:
4469         done_path_create(&new_path, new_dentry);
4470 out:
4471         path_put(&old_path);
4472
4473         return error;
4474 }