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                 rb = (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
2432
2433                 trace_ocfs2_calc_refcount_meta_credits_iterate(
2434                                 recs_add, (unsigned long long)cpos, clusters,
2435                                 (unsigned long long)le64_to_cpu(rec.r_cpos),
2436                                 le32_to_cpu(rec.r_clusters),
2437                                 le32_to_cpu(rec.r_refcount), index);
2438
2439                 len = min((u64)cpos + clusters, le64_to_cpu(rec.r_cpos) +
2440                           le32_to_cpu(rec.r_clusters)) - cpos;
2441                 /*
2442                  * We record all the records which will be inserted to the
2443                  * same refcount block, so that we can tell exactly whether
2444                  * we need a new refcount block or not.
2445                  *
2446                  * If we will insert a new one, this is easy and only happens
2447                  * during adding refcounted flag to the extent, so we don't
2448                  * have a chance of spliting. We just need one record.
2449                  *
2450                  * If the refcount rec already exists, that would be a little
2451                  * complicated. we may have to:
2452                  * 1) split at the beginning if the start pos isn't aligned.
2453                  *    we need 1 more record in this case.
2454                  * 2) split int the end if the end pos isn't aligned.
2455                  *    we need 1 more record in this case.
2456                  * 3) split in the middle because of file system fragmentation.
2457                  *    we need 2 more records in this case(we can't detect this
2458                  *    beforehand, so always think of the worst case).
2459                  */
2460                 if (rec.r_refcount) {
2461                         recs_add += 2;
2462                         /* Check whether we need a split at the beginning. */
2463                         if (cpos == start_cpos &&
2464                             cpos != le64_to_cpu(rec.r_cpos))
2465                                 recs_add++;
2466
2467                         /* Check whether we need a split in the end. */
2468                         if (cpos + clusters < le64_to_cpu(rec.r_cpos) +
2469                             le32_to_cpu(rec.r_clusters))
2470                                 recs_add++;
2471                 } else
2472                         recs_add++;
2473
2474                 brelse(ref_leaf_bh);
2475                 ref_leaf_bh = NULL;
2476                 clusters -= len;
2477                 cpos += len;
2478         }
2479
2480         if (prev_bh) {
2481                 rb = (struct ocfs2_refcount_block *)prev_bh->b_data;
2482
2483                 if (le16_to_cpu(rb->rf_records.rl_used) + recs_add >
2484                     le16_to_cpu(rb->rf_records.rl_count))
2485                         ref_blocks++;
2486
2487                 *credits += 1;
2488         }
2489
2490         if (!ref_blocks)
2491                 goto out;
2492
2493         *meta_add += ref_blocks;
2494         *credits += ref_blocks;
2495
2496         /*
2497          * So we may need ref_blocks to insert into the tree.
2498          * That also means we need to change the b-tree and add that number
2499          * of records since we never merge them.
2500          * We need one more block for expansion since the new created leaf
2501          * block is also full and needs split.
2502          */
2503         rb = (struct ocfs2_refcount_block *)ref_root_bh->b_data;
2504         if (le32_to_cpu(rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL) {
2505                 struct ocfs2_extent_tree et;
2506
2507                 ocfs2_init_refcount_extent_tree(&et, ci, ref_root_bh);
2508                 *meta_add += ocfs2_extend_meta_needed(et.et_root_el);
2509                 *credits += ocfs2_calc_extend_credits(sb,
2510                                                       et.et_root_el);
2511         } else {
2512                 *credits += OCFS2_EXPAND_REFCOUNT_TREE_CREDITS;
2513                 *meta_add += 1;
2514         }
2515
2516 out:
2517
2518         trace_ocfs2_calc_refcount_meta_credits(
2519                 (unsigned long long)start_cpos, clusters,
2520                 *meta_add, *credits);
2521         brelse(ref_leaf_bh);
2522         brelse(prev_bh);
2523         return ret;
2524 }
2525
2526 /*
2527  * For refcount tree, we will decrease some contiguous clusters
2528  * refcount count, so just go through it to see how many blocks
2529  * we gonna touch and whether we need to create new blocks.
2530  *
2531  * Normally the refcount blocks store these refcount should be
2532  * contiguous also, so that we can get the number easily.
2533  * We will at most add split 2 refcount records and 2 more
2534  * refcount blocks, so just check it in a rough way.
2535  *
2536  * Caller must hold refcount tree lock.
2537  */
2538 int ocfs2_prepare_refcount_change_for_del(struct inode *inode,
2539                                           u64 refcount_loc,
2540                                           u64 phys_blkno,
2541                                           u32 clusters,
2542                                           int *credits,
2543                                           int *ref_blocks)
2544 {
2545         int ret;
2546         struct ocfs2_inode_info *oi = OCFS2_I(inode);
2547         struct buffer_head *ref_root_bh = NULL;
2548         struct ocfs2_refcount_tree *tree;
2549         u64 start_cpos = ocfs2_blocks_to_clusters(inode->i_sb, phys_blkno);
2550
2551         if (!ocfs2_refcount_tree(OCFS2_SB(inode->i_sb))) {
2552                 ocfs2_error(inode->i_sb, "Inode %lu want to use refcount "
2553                             "tree, but the feature bit is not set in the "
2554                             "super block.", inode->i_ino);
2555                 ret = -EROFS;
2556                 goto out;
2557         }
2558
2559         BUG_ON(!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL));
2560
2561         ret = ocfs2_get_refcount_tree(OCFS2_SB(inode->i_sb),
2562                                       refcount_loc, &tree);
2563         if (ret) {
2564                 mlog_errno(ret);
2565                 goto out;
2566         }
2567
2568         ret = ocfs2_read_refcount_block(&tree->rf_ci, refcount_loc,
2569                                         &ref_root_bh);
2570         if (ret) {
2571                 mlog_errno(ret);
2572                 goto out;
2573         }
2574
2575         ret = ocfs2_calc_refcount_meta_credits(inode->i_sb,
2576                                                &tree->rf_ci,
2577                                                ref_root_bh,
2578                                                start_cpos, clusters,
2579                                                ref_blocks, credits);
2580         if (ret) {
2581                 mlog_errno(ret);
2582                 goto out;
2583         }
2584
2585         trace_ocfs2_prepare_refcount_change_for_del(*ref_blocks, *credits);
2586
2587 out:
2588         brelse(ref_root_bh);
2589         return ret;
2590 }
2591
2592 #define MAX_CONTIG_BYTES        1048576
2593
2594 static inline unsigned int ocfs2_cow_contig_clusters(struct super_block *sb)
2595 {
2596         return ocfs2_clusters_for_bytes(sb, MAX_CONTIG_BYTES);
2597 }
2598
2599 static inline unsigned int ocfs2_cow_contig_mask(struct super_block *sb)
2600 {
2601         return ~(ocfs2_cow_contig_clusters(sb) - 1);
2602 }
2603
2604 /*
2605  * Given an extent that starts at 'start' and an I/O that starts at 'cpos',
2606  * find an offset (start + (n * contig_clusters)) that is closest to cpos
2607  * while still being less than or equal to it.
2608  *
2609  * The goal is to break the extent at a multiple of contig_clusters.
2610  */
2611 static inline unsigned int ocfs2_cow_align_start(struct super_block *sb,
2612                                                  unsigned int start,
2613                                                  unsigned int cpos)
2614 {
2615         BUG_ON(start > cpos);
2616
2617         return start + ((cpos - start) & ocfs2_cow_contig_mask(sb));
2618 }
2619
2620 /*
2621  * Given a cluster count of len, pad it out so that it is a multiple
2622  * of contig_clusters.
2623  */
2624 static inline unsigned int ocfs2_cow_align_length(struct super_block *sb,
2625                                                   unsigned int len)
2626 {
2627         unsigned int padded =
2628                 (len + (ocfs2_cow_contig_clusters(sb) - 1)) &
2629                 ocfs2_cow_contig_mask(sb);
2630
2631         /* Did we wrap? */
2632         if (padded < len)
2633                 padded = UINT_MAX;
2634
2635         return padded;
2636 }
2637
2638 /*
2639  * Calculate out the start and number of virtual clusters we need to to CoW.
2640  *
2641  * cpos is vitual start cluster position we want to do CoW in a
2642  * file and write_len is the cluster length.
2643  * max_cpos is the place where we want to stop CoW intentionally.
2644  *
2645  * Normal we will start CoW from the beginning of extent record cotaining cpos.
2646  * We try to break up extents on boundaries of MAX_CONTIG_BYTES so that we
2647  * get good I/O from the resulting extent tree.
2648  */
2649 static int ocfs2_refcount_cal_cow_clusters(struct inode *inode,
2650                                            struct ocfs2_extent_list *el,
2651                                            u32 cpos,
2652                                            u32 write_len,
2653                                            u32 max_cpos,
2654                                            u32 *cow_start,
2655                                            u32 *cow_len)
2656 {
2657         int ret = 0;
2658         int tree_height = le16_to_cpu(el->l_tree_depth), i;
2659         struct buffer_head *eb_bh = NULL;
2660         struct ocfs2_extent_block *eb = NULL;
2661         struct ocfs2_extent_rec *rec;
2662         unsigned int want_clusters, rec_end = 0;
2663         int contig_clusters = ocfs2_cow_contig_clusters(inode->i_sb);
2664         int leaf_clusters;
2665
2666         BUG_ON(cpos + write_len > max_cpos);
2667
2668         if (tree_height > 0) {
2669                 ret = ocfs2_find_leaf(INODE_CACHE(inode), el, cpos, &eb_bh);
2670                 if (ret) {
2671                         mlog_errno(ret);
2672                         goto out;
2673                 }
2674
2675                 eb = (struct ocfs2_extent_block *) eb_bh->b_data;
2676                 el = &eb->h_list;
2677
2678                 if (el->l_tree_depth) {
2679                         ocfs2_error(inode->i_sb,
2680                                     "Inode %lu has non zero tree depth in "
2681                                     "leaf block %llu\n", inode->i_ino,
2682                                     (unsigned long long)eb_bh->b_blocknr);
2683                         ret = -EROFS;
2684                         goto out;
2685                 }
2686         }
2687
2688         *cow_len = 0;
2689         for (i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
2690                 rec = &el->l_recs[i];
2691
2692                 if (ocfs2_is_empty_extent(rec)) {
2693                         mlog_bug_on_msg(i != 0, "Inode %lu has empty record in "
2694                                         "index %d\n", inode->i_ino, i);
2695                         continue;
2696                 }
2697
2698                 if (le32_to_cpu(rec->e_cpos) +
2699                     le16_to_cpu(rec->e_leaf_clusters) <= cpos)
2700                         continue;
2701
2702                 if (*cow_len == 0) {
2703                         /*
2704                          * We should find a refcounted record in the
2705                          * first pass.
2706                          */
2707                         BUG_ON(!(rec->e_flags & OCFS2_EXT_REFCOUNTED));
2708                         *cow_start = le32_to_cpu(rec->e_cpos);
2709                 }
2710
2711                 /*
2712                  * If we encounter a hole, a non-refcounted record or
2713                  * pass the max_cpos, stop the search.
2714                  */
2715                 if ((!(rec->e_flags & OCFS2_EXT_REFCOUNTED)) ||
2716                     (*cow_len && rec_end != le32_to_cpu(rec->e_cpos)) ||
2717                     (max_cpos <= le32_to_cpu(rec->e_cpos)))
2718                         break;
2719
2720                 leaf_clusters = le16_to_cpu(rec->e_leaf_clusters);
2721                 rec_end = le32_to_cpu(rec->e_cpos) + leaf_clusters;
2722                 if (rec_end > max_cpos) {
2723                         rec_end = max_cpos;
2724                         leaf_clusters = rec_end - le32_to_cpu(rec->e_cpos);
2725                 }
2726
2727                 /*
2728                  * How many clusters do we actually need from
2729                  * this extent?  First we see how many we actually
2730                  * need to complete the write.  If that's smaller
2731                  * than contig_clusters, we try for contig_clusters.
2732                  */
2733                 if (!*cow_len)
2734                         want_clusters = write_len;
2735                 else
2736                         want_clusters = (cpos + write_len) -
2737                                 (*cow_start + *cow_len);
2738                 if (want_clusters < contig_clusters)
2739                         want_clusters = contig_clusters;
2740
2741                 /*
2742                  * If the write does not cover the whole extent, we
2743                  * need to calculate how we're going to split the extent.
2744                  * We try to do it on contig_clusters boundaries.
2745                  *
2746                  * Any extent smaller than contig_clusters will be
2747                  * CoWed in its entirety.
2748                  */
2749                 if (leaf_clusters <= contig_clusters)
2750                         *cow_len += leaf_clusters;
2751                 else if (*cow_len || (*cow_start == cpos)) {
2752                         /*
2753                          * This extent needs to be CoW'd from its
2754                          * beginning, so all we have to do is compute
2755                          * how many clusters to grab.  We align
2756                          * want_clusters to the edge of contig_clusters
2757                          * to get better I/O.
2758                          */
2759                         want_clusters = ocfs2_cow_align_length(inode->i_sb,
2760                                                                want_clusters);
2761
2762                         if (leaf_clusters < want_clusters)
2763                                 *cow_len += leaf_clusters;
2764                         else
2765                                 *cow_len += want_clusters;
2766                 } else if ((*cow_start + contig_clusters) >=
2767                            (cpos + write_len)) {
2768                         /*
2769                          * Breaking off contig_clusters at the front
2770                          * of the extent will cover our write.  That's
2771                          * easy.
2772                          */
2773                         *cow_len = contig_clusters;
2774                 } else if ((rec_end - cpos) <= contig_clusters) {
2775                         /*
2776                          * Breaking off contig_clusters at the tail of
2777                          * this extent will cover cpos.
2778                          */
2779                         *cow_start = rec_end - contig_clusters;
2780                         *cow_len = contig_clusters;
2781                 } else if ((rec_end - cpos) <= want_clusters) {
2782                         /*
2783                          * While we can't fit the entire write in this
2784                          * extent, we know that the write goes from cpos
2785                          * to the end of the extent.  Break that off.
2786                          * We try to break it at some multiple of
2787                          * contig_clusters from the front of the extent.
2788                          * Failing that (ie, cpos is within
2789                          * contig_clusters of the front), we'll CoW the
2790                          * entire extent.
2791                          */
2792                         *cow_start = ocfs2_cow_align_start(inode->i_sb,
2793                                                            *cow_start, cpos);
2794                         *cow_len = rec_end - *cow_start;
2795                 } else {
2796                         /*
2797                          * Ok, the entire write lives in the middle of
2798                          * this extent.  Let's try to slice the extent up
2799                          * nicely.  Optimally, our CoW region starts at
2800                          * m*contig_clusters from the beginning of the
2801                          * extent and goes for n*contig_clusters,
2802                          * covering the entire write.
2803                          */
2804                         *cow_start = ocfs2_cow_align_start(inode->i_sb,
2805                                                            *cow_start, cpos);
2806
2807                         want_clusters = (cpos + write_len) - *cow_start;
2808                         want_clusters = ocfs2_cow_align_length(inode->i_sb,
2809                                                                want_clusters);
2810                         if (*cow_start + want_clusters <= rec_end)
2811                                 *cow_len = want_clusters;
2812                         else
2813                                 *cow_len = rec_end - *cow_start;
2814                 }
2815
2816                 /* Have we covered our entire write yet? */
2817                 if ((*cow_start + *cow_len) >= (cpos + write_len))
2818                         break;
2819
2820                 /*
2821                  * If we reach the end of the extent block and don't get enough
2822                  * clusters, continue with the next extent block if possible.
2823                  */
2824                 if (i + 1 == le16_to_cpu(el->l_next_free_rec) &&
2825                     eb && eb->h_next_leaf_blk) {
2826                         brelse(eb_bh);
2827                         eb_bh = NULL;
2828
2829                         ret = ocfs2_read_extent_block(INODE_CACHE(inode),
2830                                                le64_to_cpu(eb->h_next_leaf_blk),
2831                                                &eb_bh);
2832                         if (ret) {
2833                                 mlog_errno(ret);
2834                                 goto out;
2835                         }
2836
2837                         eb = (struct ocfs2_extent_block *) eb_bh->b_data;
2838                         el = &eb->h_list;
2839                         i = -1;
2840                 }
2841         }
2842
2843 out:
2844         brelse(eb_bh);
2845         return ret;
2846 }
2847
2848 /*
2849  * Prepare meta_ac, data_ac and calculate credits when we want to add some
2850  * num_clusters in data_tree "et" and change the refcount for the old
2851  * clusters(starting form p_cluster) in the refcount tree.
2852  *
2853  * Note:
2854  * 1. since we may split the old tree, so we at most will need num_clusters + 2
2855  *    more new leaf records.
2856  * 2. In some case, we may not need to reserve new clusters(e.g, reflink), so
2857  *    just give data_ac = NULL.
2858  */
2859 static int ocfs2_lock_refcount_allocators(struct super_block *sb,
2860                                         u32 p_cluster, u32 num_clusters,
2861                                         struct ocfs2_extent_tree *et,
2862                                         struct ocfs2_caching_info *ref_ci,
2863                                         struct buffer_head *ref_root_bh,
2864                                         struct ocfs2_alloc_context **meta_ac,
2865                                         struct ocfs2_alloc_context **data_ac,
2866                                         int *credits)
2867 {
2868         int ret = 0, meta_add = 0;
2869         int num_free_extents = ocfs2_num_free_extents(OCFS2_SB(sb), et);
2870
2871         if (num_free_extents < 0) {
2872                 ret = num_free_extents;
2873                 mlog_errno(ret);
2874                 goto out;
2875         }
2876
2877         if (num_free_extents < num_clusters + 2)
2878                 meta_add =
2879                         ocfs2_extend_meta_needed(et->et_root_el);
2880
2881         *credits += ocfs2_calc_extend_credits(sb, et->et_root_el);
2882
2883         ret = ocfs2_calc_refcount_meta_credits(sb, ref_ci, ref_root_bh,
2884                                                p_cluster, num_clusters,
2885                                                &meta_add, credits);
2886         if (ret) {
2887                 mlog_errno(ret);
2888                 goto out;
2889         }
2890
2891         trace_ocfs2_lock_refcount_allocators(meta_add, *credits);
2892         ret = ocfs2_reserve_new_metadata_blocks(OCFS2_SB(sb), meta_add,
2893                                                 meta_ac);
2894         if (ret) {
2895                 mlog_errno(ret);
2896                 goto out;
2897         }
2898
2899         if (data_ac) {
2900                 ret = ocfs2_reserve_clusters(OCFS2_SB(sb), num_clusters,
2901                                              data_ac);
2902                 if (ret)
2903                         mlog_errno(ret);
2904         }
2905
2906 out:
2907         if (ret) {
2908                 if (*meta_ac) {
2909                         ocfs2_free_alloc_context(*meta_ac);
2910                         *meta_ac = NULL;
2911                 }
2912         }
2913
2914         return ret;
2915 }
2916
2917 static int ocfs2_clear_cow_buffer(handle_t *handle, struct buffer_head *bh)
2918 {
2919         BUG_ON(buffer_dirty(bh));
2920
2921         clear_buffer_mapped(bh);
2922
2923         return 0;
2924 }
2925
2926 int ocfs2_duplicate_clusters_by_page(handle_t *handle,
2927                                      struct inode *inode,
2928                                      u32 cpos, u32 old_cluster,
2929                                      u32 new_cluster, u32 new_len)
2930 {
2931         int ret = 0, partial;
2932         struct super_block *sb = inode->i_sb;
2933         u64 new_block = ocfs2_clusters_to_blocks(sb, new_cluster);
2934         struct page *page;
2935         pgoff_t page_index;
2936         unsigned int from, to, readahead_pages;
2937         loff_t offset, end, map_end;
2938         struct address_space *mapping = inode->i_mapping;
2939
2940         trace_ocfs2_duplicate_clusters_by_page(cpos, old_cluster,
2941                                                new_cluster, new_len);
2942
2943         readahead_pages =
2944                 (ocfs2_cow_contig_clusters(sb) <<
2945                  OCFS2_SB(sb)->s_clustersize_bits) >> PAGE_CACHE_SHIFT;
2946         offset = ((loff_t)cpos) << OCFS2_SB(sb)->s_clustersize_bits;
2947         end = offset + (new_len << OCFS2_SB(sb)->s_clustersize_bits);
2948         /*
2949          * We only duplicate pages until we reach the page contains i_size - 1.
2950          * So trim 'end' to i_size.
2951          */
2952         if (end > i_size_read(inode))
2953                 end = i_size_read(inode);
2954
2955         while (offset < end) {
2956                 page_index = offset >> PAGE_CACHE_SHIFT;
2957                 map_end = ((loff_t)page_index + 1) << PAGE_CACHE_SHIFT;
2958                 if (map_end > end)
2959                         map_end = end;
2960
2961                 /* from, to is the offset within the page. */
2962                 from = offset & (PAGE_CACHE_SIZE - 1);
2963                 to = PAGE_CACHE_SIZE;
2964                 if (map_end & (PAGE_CACHE_SIZE - 1))
2965                         to = map_end & (PAGE_CACHE_SIZE - 1);
2966
2967                 page = find_or_create_page(mapping, page_index, GFP_NOFS);
2968                 if (!page) {
2969                         ret = -ENOMEM;
2970                         mlog_errno(ret);
2971                         break;
2972                 }
2973
2974                 /*
2975                  * In case PAGE_CACHE_SIZE <= CLUSTER_SIZE, This page
2976                  * can't be dirtied before we CoW it out.
2977                  */
2978                 if (PAGE_CACHE_SIZE <= OCFS2_SB(sb)->s_clustersize)
2979                         BUG_ON(PageDirty(page));
2980
2981                 if (!PageUptodate(page)) {
2982                         ret = block_read_full_page(page, ocfs2_get_block);
2983                         if (ret) {
2984                                 mlog_errno(ret);
2985                                 goto unlock;
2986                         }
2987                         lock_page(page);
2988                 }
2989
2990                 if (page_has_buffers(page)) {
2991                         ret = walk_page_buffers(handle, page_buffers(page),
2992                                                 from, to, &partial,
2993                                                 ocfs2_clear_cow_buffer);
2994                         if (ret) {
2995                                 mlog_errno(ret);
2996                                 goto unlock;
2997                         }
2998                 }
2999
3000                 ocfs2_map_and_dirty_page(inode,
3001                                          handle, from, to,
3002                                          page, 0, &new_block);
3003                 mark_page_accessed(page);
3004 unlock:
3005                 unlock_page(page);
3006                 page_cache_release(page);
3007                 page = NULL;
3008                 offset = map_end;
3009                 if (ret)
3010                         break;
3011         }
3012
3013         return ret;
3014 }
3015
3016 int ocfs2_duplicate_clusters_by_jbd(handle_t *handle,
3017                                     struct inode *inode,
3018                                     u32 cpos, u32 old_cluster,
3019                                     u32 new_cluster, u32 new_len)
3020 {
3021         int ret = 0;
3022         struct super_block *sb = inode->i_sb;
3023         struct ocfs2_caching_info *ci = INODE_CACHE(inode);
3024         int i, blocks = ocfs2_clusters_to_blocks(sb, new_len);
3025         u64 old_block = ocfs2_clusters_to_blocks(sb, old_cluster);
3026         u64 new_block = ocfs2_clusters_to_blocks(sb, new_cluster);
3027         struct ocfs2_super *osb = OCFS2_SB(sb);
3028         struct buffer_head *old_bh = NULL;
3029         struct buffer_head *new_bh = NULL;
3030
3031         trace_ocfs2_duplicate_clusters_by_page(cpos, old_cluster,
3032                                                new_cluster, new_len);
3033
3034         for (i = 0; i < blocks; i++, old_block++, new_block++) {
3035                 new_bh = sb_getblk(osb->sb, new_block);
3036                 if (new_bh == NULL) {
3037                         ret = -ENOMEM;
3038                         mlog_errno(ret);
3039                         break;
3040                 }
3041
3042                 ocfs2_set_new_buffer_uptodate(ci, new_bh);
3043
3044                 ret = ocfs2_read_block(ci, old_block, &old_bh, NULL);
3045                 if (ret) {
3046                         mlog_errno(ret);
3047                         break;
3048                 }
3049
3050                 ret = ocfs2_journal_access(handle, ci, new_bh,
3051                                            OCFS2_JOURNAL_ACCESS_CREATE);
3052                 if (ret) {
3053                         mlog_errno(ret);
3054                         break;
3055                 }
3056
3057                 memcpy(new_bh->b_data, old_bh->b_data, sb->s_blocksize);
3058                 ocfs2_journal_dirty(handle, new_bh);
3059
3060                 brelse(new_bh);
3061                 brelse(old_bh);
3062                 new_bh = NULL;
3063                 old_bh = NULL;
3064         }
3065
3066         brelse(new_bh);
3067         brelse(old_bh);
3068         return ret;
3069 }
3070
3071 static int ocfs2_clear_ext_refcount(handle_t *handle,
3072                                     struct ocfs2_extent_tree *et,
3073                                     u32 cpos, u32 p_cluster, u32 len,
3074                                     unsigned int ext_flags,
3075                                     struct ocfs2_alloc_context *meta_ac,
3076                                     struct ocfs2_cached_dealloc_ctxt *dealloc)
3077 {
3078         int ret, index;
3079         struct ocfs2_extent_rec replace_rec;
3080         struct ocfs2_path *path = NULL;
3081         struct ocfs2_extent_list *el;
3082         struct super_block *sb = ocfs2_metadata_cache_get_super(et->et_ci);
3083         u64 ino = ocfs2_metadata_cache_owner(et->et_ci);
3084
3085         trace_ocfs2_clear_ext_refcount((unsigned long long)ino,
3086                                        cpos, len, p_cluster, ext_flags);
3087
3088         memset(&replace_rec, 0, sizeof(replace_rec));
3089         replace_rec.e_cpos = cpu_to_le32(cpos);
3090         replace_rec.e_leaf_clusters = cpu_to_le16(len);
3091         replace_rec.e_blkno = cpu_to_le64(ocfs2_clusters_to_blocks(sb,
3092                                                                    p_cluster));
3093         replace_rec.e_flags = ext_flags;
3094         replace_rec.e_flags &= ~OCFS2_EXT_REFCOUNTED;
3095
3096         path = ocfs2_new_path_from_et(et);
3097         if (!path) {
3098                 ret = -ENOMEM;
3099                 mlog_errno(ret);
3100                 goto out;
3101         }
3102
3103         ret = ocfs2_find_path(et->et_ci, path, cpos);
3104         if (ret) {
3105                 mlog_errno(ret);
3106                 goto out;
3107         }
3108
3109         el = path_leaf_el(path);
3110
3111         index = ocfs2_search_extent_list(el, cpos);
3112         if (index == -1 || index >= le16_to_cpu(el->l_next_free_rec)) {
3113                 ocfs2_error(sb,
3114                             "Inode %llu has an extent at cpos %u which can no "
3115                             "longer be found.\n",
3116                             (unsigned long long)ino, cpos);
3117                 ret = -EROFS;
3118                 goto out;
3119         }
3120
3121         ret = ocfs2_split_extent(handle, et, path, index,
3122                                  &replace_rec, meta_ac, dealloc);
3123         if (ret)
3124                 mlog_errno(ret);
3125
3126 out:
3127         ocfs2_free_path(path);
3128         return ret;
3129 }
3130
3131 static int ocfs2_replace_clusters(handle_t *handle,
3132                                   struct ocfs2_cow_context *context,
3133                                   u32 cpos, u32 old,
3134                                   u32 new, u32 len,
3135                                   unsigned int ext_flags)
3136 {
3137         int ret;
3138         struct ocfs2_caching_info *ci = context->data_et.et_ci;
3139         u64 ino = ocfs2_metadata_cache_owner(ci);
3140
3141         trace_ocfs2_replace_clusters((unsigned long long)ino,
3142                                      cpos, old, new, len, ext_flags);
3143
3144         /*If the old clusters is unwritten, no need to duplicate. */
3145         if (!(ext_flags & OCFS2_EXT_UNWRITTEN)) {
3146                 ret = context->cow_duplicate_clusters(handle, context->inode,
3147                                                       cpos, old, new, len);
3148                 if (ret) {
3149                         mlog_errno(ret);
3150                         goto out;
3151                 }
3152         }
3153
3154         ret = ocfs2_clear_ext_refcount(handle, &context->data_et,
3155                                        cpos, new, len, ext_flags,
3156                                        context->meta_ac, &context->dealloc);
3157         if (ret)
3158                 mlog_errno(ret);
3159 out:
3160         return ret;
3161 }
3162
3163 int ocfs2_cow_sync_writeback(struct super_block *sb,
3164                              struct inode *inode,
3165                              u32 cpos, u32 num_clusters)
3166 {
3167         int ret = 0;
3168         loff_t offset, end, map_end;
3169         pgoff_t page_index;
3170         struct page *page;
3171
3172         if (ocfs2_should_order_data(inode))
3173                 return 0;
3174
3175         offset = ((loff_t)cpos) << OCFS2_SB(sb)->s_clustersize_bits;
3176         end = offset + (num_clusters << OCFS2_SB(sb)->s_clustersize_bits);
3177
3178         ret = filemap_fdatawrite_range(inode->i_mapping,
3179                                        offset, end - 1);
3180         if (ret < 0) {
3181                 mlog_errno(ret);
3182                 return ret;
3183         }
3184
3185         while (offset < end) {
3186                 page_index = offset >> PAGE_CACHE_SHIFT;
3187                 map_end = ((loff_t)page_index + 1) << PAGE_CACHE_SHIFT;
3188                 if (map_end > end)
3189                         map_end = end;
3190
3191                 page = find_or_create_page(inode->i_mapping,
3192                                            page_index, GFP_NOFS);
3193                 BUG_ON(!page);
3194
3195                 wait_on_page_writeback(page);
3196                 if (PageError(page)) {
3197                         ret = -EIO;
3198                         mlog_errno(ret);
3199                 } else
3200                         mark_page_accessed(page);
3201
3202                 unlock_page(page);
3203                 page_cache_release(page);
3204                 page = NULL;
3205                 offset = map_end;
3206                 if (ret)
3207                         break;
3208         }
3209
3210         return ret;
3211 }
3212
3213 static int ocfs2_di_get_clusters(struct ocfs2_cow_context *context,
3214                                  u32 v_cluster, u32 *p_cluster,
3215                                  u32 *num_clusters,
3216                                  unsigned int *extent_flags)
3217 {
3218         return ocfs2_get_clusters(context->inode, v_cluster, p_cluster,
3219                                   num_clusters, extent_flags);
3220 }
3221
3222 static int ocfs2_make_clusters_writable(struct super_block *sb,
3223                                         struct ocfs2_cow_context *context,
3224                                         u32 cpos, u32 p_cluster,
3225                                         u32 num_clusters, unsigned int e_flags)
3226 {
3227         int ret, delete, index, credits =  0;
3228         u32 new_bit, new_len, orig_num_clusters;
3229         unsigned int set_len;
3230         struct ocfs2_super *osb = OCFS2_SB(sb);
3231         handle_t *handle;
3232         struct buffer_head *ref_leaf_bh = NULL;
3233         struct ocfs2_caching_info *ref_ci = &context->ref_tree->rf_ci;
3234         struct ocfs2_refcount_rec rec;
3235
3236         trace_ocfs2_make_clusters_writable(cpos, p_cluster,
3237                                            num_clusters, e_flags);
3238
3239         ret = ocfs2_lock_refcount_allocators(sb, p_cluster, num_clusters,
3240                                              &context->data_et,
3241                                              ref_ci,
3242                                              context->ref_root_bh,
3243                                              &context->meta_ac,
3244                                              &context->data_ac, &credits);
3245         if (ret) {
3246                 mlog_errno(ret);
3247                 return ret;
3248         }
3249
3250         if (context->post_refcount)
3251                 credits += context->post_refcount->credits;
3252
3253         credits += context->extra_credits;
3254         handle = ocfs2_start_trans(osb, credits);
3255         if (IS_ERR(handle)) {
3256                 ret = PTR_ERR(handle);
3257                 mlog_errno(ret);
3258                 goto out;
3259         }
3260
3261         orig_num_clusters = num_clusters;
3262
3263         while (num_clusters) {
3264                 ret = ocfs2_get_refcount_rec(ref_ci, context->ref_root_bh,
3265                                              p_cluster, num_clusters,
3266                                              &rec, &index, &ref_leaf_bh);
3267                 if (ret) {
3268                         mlog_errno(ret);
3269                         goto out_commit;
3270                 }
3271
3272                 BUG_ON(!rec.r_refcount);
3273                 set_len = min((u64)p_cluster + num_clusters,
3274                               le64_to_cpu(rec.r_cpos) +
3275                               le32_to_cpu(rec.r_clusters)) - p_cluster;
3276
3277                 /*
3278                  * There are many different situation here.
3279                  * 1. If refcount == 1, remove the flag and don't COW.
3280                  * 2. If refcount > 1, allocate clusters.
3281                  *    Here we may not allocate r_len once at a time, so continue
3282                  *    until we reach num_clusters.
3283                  */
3284                 if (le32_to_cpu(rec.r_refcount) == 1) {
3285                         delete = 0;
3286                         ret = ocfs2_clear_ext_refcount(handle,
3287                                                        &context->data_et,
3288                                                        cpos, p_cluster,
3289                                                        set_len, e_flags,
3290                                                        context->meta_ac,
3291                                                        &context->dealloc);
3292                         if (ret) {
3293                                 mlog_errno(ret);
3294                                 goto out_commit;
3295                         }
3296                 } else {
3297                         delete = 1;
3298
3299                         ret = __ocfs2_claim_clusters(handle,
3300                                                      context->data_ac,
3301                                                      1, set_len,
3302                                                      &new_bit, &new_len);
3303                         if (ret) {
3304                                 mlog_errno(ret);
3305                                 goto out_commit;
3306                         }
3307
3308                         ret = ocfs2_replace_clusters(handle, context,
3309                                                      cpos, p_cluster, new_bit,
3310                                                      new_len, e_flags);
3311                         if (ret) {
3312                                 mlog_errno(ret);
3313                                 goto out_commit;
3314                         }
3315                         set_len = new_len;
3316                 }
3317
3318                 ret = __ocfs2_decrease_refcount(handle, ref_ci,
3319                                                 context->ref_root_bh,
3320                                                 p_cluster, set_len,
3321                                                 context->meta_ac,
3322                                                 &context->dealloc, delete);
3323                 if (ret) {
3324                         mlog_errno(ret);
3325                         goto out_commit;
3326                 }
3327
3328                 cpos += set_len;
3329                 p_cluster += set_len;
3330                 num_clusters -= set_len;
3331                 brelse(ref_leaf_bh);
3332                 ref_leaf_bh = NULL;
3333         }
3334
3335         /* handle any post_cow action. */
3336         if (context->post_refcount && context->post_refcount->func) {
3337                 ret = context->post_refcount->func(context->inode, handle,
3338                                                 context->post_refcount->para);
3339                 if (ret) {
3340                         mlog_errno(ret);
3341                         goto out_commit;
3342                 }
3343         }
3344
3345         /*
3346          * Here we should write the new page out first if we are
3347          * in write-back mode.
3348          */
3349         if (context->get_clusters == ocfs2_di_get_clusters) {
3350                 ret = ocfs2_cow_sync_writeback(sb, context->inode, cpos,
3351                                                orig_num_clusters);
3352                 if (ret)
3353                         mlog_errno(ret);
3354         }
3355
3356 out_commit:
3357         ocfs2_commit_trans(osb, handle);
3358
3359 out:
3360         if (context->data_ac) {
3361                 ocfs2_free_alloc_context(context->data_ac);
3362                 context->data_ac = NULL;
3363         }
3364         if (context->meta_ac) {
3365                 ocfs2_free_alloc_context(context->meta_ac);
3366                 context->meta_ac = NULL;
3367         }
3368         brelse(ref_leaf_bh);
3369
3370         return ret;
3371 }
3372
3373 static int ocfs2_replace_cow(struct ocfs2_cow_context *context)
3374 {
3375         int ret = 0;
3376         struct inode *inode = context->inode;
3377         u32 cow_start = context->cow_start, cow_len = context->cow_len;
3378         u32 p_cluster, num_clusters;
3379         unsigned int ext_flags;
3380         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
3381
3382         if (!ocfs2_refcount_tree(OCFS2_SB(inode->i_sb))) {
3383                 ocfs2_error(inode->i_sb, "Inode %lu want to use refcount "
3384                             "tree, but the feature bit is not set in the "
3385                             "super block.", inode->i_ino);
3386                 return -EROFS;
3387         }
3388
3389         ocfs2_init_dealloc_ctxt(&context->dealloc);
3390
3391         while (cow_len) {
3392                 ret = context->get_clusters(context, cow_start, &p_cluster,
3393                                             &num_clusters, &ext_flags);
3394                 if (ret) {
3395                         mlog_errno(ret);
3396                         break;
3397                 }
3398
3399                 BUG_ON(!(ext_flags & OCFS2_EXT_REFCOUNTED));
3400
3401                 if (cow_len < num_clusters)
3402                         num_clusters = cow_len;
3403
3404                 ret = ocfs2_make_clusters_writable(inode->i_sb, context,
3405                                                    cow_start, p_cluster,
3406                                                    num_clusters, ext_flags);
3407                 if (ret) {
3408                         mlog_errno(ret);
3409                         break;
3410                 }
3411
3412                 cow_len -= num_clusters;
3413                 cow_start += num_clusters;
3414         }
3415
3416         if (ocfs2_dealloc_has_cluster(&context->dealloc)) {
3417                 ocfs2_schedule_truncate_log_flush(osb, 1);
3418                 ocfs2_run_deallocs(osb, &context->dealloc);
3419         }
3420
3421         return ret;
3422 }
3423
3424 /*
3425  * Starting at cpos, try to CoW write_len clusters.  Don't CoW
3426  * past max_cpos.  This will stop when it runs into a hole or an
3427  * unrefcounted extent.
3428  */
3429 static int ocfs2_refcount_cow_hunk(struct inode *inode,
3430                                    struct buffer_head *di_bh,
3431                                    u32 cpos, u32 write_len, u32 max_cpos)
3432 {
3433         int ret;
3434         u32 cow_start = 0, cow_len = 0;
3435         struct ocfs2_inode_info *oi = OCFS2_I(inode);
3436         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
3437         struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
3438         struct buffer_head *ref_root_bh = NULL;
3439         struct ocfs2_refcount_tree *ref_tree;
3440         struct ocfs2_cow_context *context = NULL;
3441
3442         BUG_ON(!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL));
3443
3444         ret = ocfs2_refcount_cal_cow_clusters(inode, &di->id2.i_list,
3445                                               cpos, write_len, max_cpos,
3446                                               &cow_start, &cow_len);
3447         if (ret) {
3448                 mlog_errno(ret);
3449                 goto out;
3450         }
3451
3452         trace_ocfs2_refcount_cow_hunk(OCFS2_I(inode)->ip_blkno,
3453                                       cpos, write_len, max_cpos,
3454                                       cow_start, cow_len);
3455
3456         BUG_ON(cow_len == 0);
3457
3458         context = kzalloc(sizeof(struct ocfs2_cow_context), GFP_NOFS);
3459         if (!context) {
3460                 ret = -ENOMEM;
3461                 mlog_errno(ret);
3462                 goto out;
3463         }
3464
3465         ret = ocfs2_lock_refcount_tree(osb, le64_to_cpu(di->i_refcount_loc),
3466                                        1, &ref_tree, &ref_root_bh);
3467         if (ret) {
3468                 mlog_errno(ret);
3469                 goto out;
3470         }
3471
3472         context->inode = inode;
3473         context->cow_start = cow_start;
3474         context->cow_len = cow_len;
3475         context->ref_tree = ref_tree;
3476         context->ref_root_bh = ref_root_bh;
3477         context->cow_duplicate_clusters = ocfs2_duplicate_clusters_by_page;
3478         context->get_clusters = ocfs2_di_get_clusters;
3479
3480         ocfs2_init_dinode_extent_tree(&context->data_et,
3481                                       INODE_CACHE(inode), di_bh);
3482
3483         ret = ocfs2_replace_cow(context);
3484         if (ret)
3485                 mlog_errno(ret);
3486
3487         /*
3488          * truncate the extent map here since no matter whether we meet with
3489          * any error during the action, we shouldn't trust cached extent map
3490          * any more.
3491          */
3492         ocfs2_extent_map_trunc(inode, cow_start);
3493
3494         ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
3495         brelse(ref_root_bh);
3496 out:
3497         kfree(context);
3498         return ret;
3499 }
3500
3501 /*
3502  * CoW any and all clusters between cpos and cpos+write_len.
3503  * Don't CoW past max_cpos.  If this returns successfully, all
3504  * clusters between cpos and cpos+write_len are safe to modify.
3505  */
3506 int ocfs2_refcount_cow(struct inode *inode,
3507                        struct buffer_head *di_bh,
3508                        u32 cpos, u32 write_len, u32 max_cpos)
3509 {
3510         int ret = 0;
3511         u32 p_cluster, num_clusters;
3512         unsigned int ext_flags;
3513
3514         while (write_len) {
3515                 ret = ocfs2_get_clusters(inode, cpos, &p_cluster,
3516                                          &num_clusters, &ext_flags);
3517                 if (ret) {
3518                         mlog_errno(ret);
3519                         break;
3520                 }
3521
3522                 if (write_len < num_clusters)
3523                         num_clusters = write_len;
3524
3525                 if (ext_flags & OCFS2_EXT_REFCOUNTED) {
3526                         ret = ocfs2_refcount_cow_hunk(inode, di_bh, cpos,
3527                                                       num_clusters, max_cpos);
3528                         if (ret) {
3529                                 mlog_errno(ret);
3530                                 break;
3531                         }
3532                 }
3533
3534                 write_len -= num_clusters;
3535                 cpos += num_clusters;
3536         }
3537
3538         return ret;
3539 }
3540
3541 static int ocfs2_xattr_value_get_clusters(struct ocfs2_cow_context *context,
3542                                           u32 v_cluster, u32 *p_cluster,
3543                                           u32 *num_clusters,
3544                                           unsigned int *extent_flags)
3545 {
3546         struct inode *inode = context->inode;
3547         struct ocfs2_xattr_value_root *xv = context->cow_object;
3548
3549         return ocfs2_xattr_get_clusters(inode, v_cluster, p_cluster,
3550                                         num_clusters, &xv->xr_list,
3551                                         extent_flags);
3552 }
3553
3554 /*
3555  * Given a xattr value root, calculate the most meta/credits we need for
3556  * refcount tree change if we truncate it to 0.
3557  */
3558 int ocfs2_refcounted_xattr_delete_need(struct inode *inode,
3559                                        struct ocfs2_caching_info *ref_ci,
3560                                        struct buffer_head *ref_root_bh,
3561                                        struct ocfs2_xattr_value_root *xv,
3562                                        int *meta_add, int *credits)
3563 {
3564         int ret = 0, index, ref_blocks = 0;
3565         u32 p_cluster, num_clusters;
3566         u32 cpos = 0, clusters = le32_to_cpu(xv->xr_clusters);
3567         struct ocfs2_refcount_block *rb;
3568         struct ocfs2_refcount_rec rec;
3569         struct buffer_head *ref_leaf_bh = NULL;
3570
3571         while (cpos < clusters) {
3572                 ret = ocfs2_xattr_get_clusters(inode, cpos, &p_cluster,
3573                                                &num_clusters, &xv->xr_list,
3574                                                NULL);
3575                 if (ret) {
3576                         mlog_errno(ret);
3577                         goto out;
3578                 }
3579
3580                 cpos += num_clusters;
3581
3582                 while (num_clusters) {
3583                         ret = ocfs2_get_refcount_rec(ref_ci, ref_root_bh,
3584                                                      p_cluster, num_clusters,
3585                                                      &rec, &index,
3586                                                      &ref_leaf_bh);
3587                         if (ret) {
3588                                 mlog_errno(ret);
3589                                 goto out;
3590                         }
3591
3592                         BUG_ON(!rec.r_refcount);
3593
3594                         rb = (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
3595
3596                         /*
3597                          * We really don't know whether the other clusters is in
3598                          * this refcount block or not, so just take the worst
3599                          * case that all the clusters are in this block and each
3600                          * one will split a refcount rec, so totally we need
3601                          * clusters * 2 new refcount rec.
3602                          */
3603                         if (le16_to_cpu(rb->rf_records.rl_used) + clusters * 2 >
3604                             le16_to_cpu(rb->rf_records.rl_count))
3605                                 ref_blocks++;
3606
3607                         *credits += 1;
3608                         brelse(ref_leaf_bh);
3609                         ref_leaf_bh = NULL;
3610
3611                         if (num_clusters <= le32_to_cpu(rec.r_clusters))
3612                                 break;
3613                         else
3614                                 num_clusters -= le32_to_cpu(rec.r_clusters);
3615                         p_cluster += num_clusters;
3616                 }
3617         }
3618
3619         *meta_add += ref_blocks;
3620         if (!ref_blocks)
3621                 goto out;
3622
3623         rb = (struct ocfs2_refcount_block *)ref_root_bh->b_data;
3624         if (le32_to_cpu(rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL)
3625                 *credits += OCFS2_EXPAND_REFCOUNT_TREE_CREDITS;
3626         else {
3627                 struct ocfs2_extent_tree et;
3628
3629                 ocfs2_init_refcount_extent_tree(&et, ref_ci, ref_root_bh);
3630                 *credits += ocfs2_calc_extend_credits(inode->i_sb,
3631                                                       et.et_root_el);
3632         }
3633
3634 out:
3635         brelse(ref_leaf_bh);
3636         return ret;
3637 }
3638
3639 /*
3640  * Do CoW for xattr.
3641  */
3642 int ocfs2_refcount_cow_xattr(struct inode *inode,
3643                              struct ocfs2_dinode *di,
3644                              struct ocfs2_xattr_value_buf *vb,
3645                              struct ocfs2_refcount_tree *ref_tree,
3646                              struct buffer_head *ref_root_bh,
3647                              u32 cpos, u32 write_len,
3648                              struct ocfs2_post_refcount *post)
3649 {
3650         int ret;
3651         struct ocfs2_xattr_value_root *xv = vb->vb_xv;
3652         struct ocfs2_inode_info *oi = OCFS2_I(inode);
3653         struct ocfs2_cow_context *context = NULL;
3654         u32 cow_start, cow_len;
3655
3656         BUG_ON(!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL));
3657
3658         ret = ocfs2_refcount_cal_cow_clusters(inode, &xv->xr_list,
3659                                               cpos, write_len, UINT_MAX,
3660                                               &cow_start, &cow_len);
3661         if (ret) {
3662                 mlog_errno(ret);
3663                 goto out;
3664         }
3665
3666         BUG_ON(cow_len == 0);
3667
3668         context = kzalloc(sizeof(struct ocfs2_cow_context), GFP_NOFS);
3669         if (!context) {
3670                 ret = -ENOMEM;
3671                 mlog_errno(ret);
3672                 goto out;
3673         }
3674
3675         context->inode = inode;
3676         context->cow_start = cow_start;
3677         context->cow_len = cow_len;
3678         context->ref_tree = ref_tree;
3679         context->ref_root_bh = ref_root_bh;
3680         context->cow_object = xv;
3681
3682         context->cow_duplicate_clusters = ocfs2_duplicate_clusters_by_jbd;
3683         /* We need the extra credits for duplicate_clusters by jbd. */
3684         context->extra_credits =
3685                 ocfs2_clusters_to_blocks(inode->i_sb, 1) * cow_len;
3686         context->get_clusters = ocfs2_xattr_value_get_clusters;
3687         context->post_refcount = post;
3688
3689         ocfs2_init_xattr_value_extent_tree(&context->data_et,
3690                                            INODE_CACHE(inode), vb);
3691
3692         ret = ocfs2_replace_cow(context);
3693         if (ret)
3694                 mlog_errno(ret);
3695
3696 out:
3697         kfree(context);
3698         return ret;
3699 }
3700
3701 /*
3702  * Insert a new extent into refcount tree and mark a extent rec
3703  * as refcounted in the dinode tree.
3704  */
3705 int ocfs2_add_refcount_flag(struct inode *inode,
3706                             struct ocfs2_extent_tree *data_et,
3707                             struct ocfs2_caching_info *ref_ci,
3708                             struct buffer_head *ref_root_bh,
3709                             u32 cpos, u32 p_cluster, u32 num_clusters,
3710                             struct ocfs2_cached_dealloc_ctxt *dealloc,
3711                             struct ocfs2_post_refcount *post)
3712 {
3713         int ret;
3714         handle_t *handle;
3715         int credits = 1, ref_blocks = 0;
3716         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
3717         struct ocfs2_alloc_context *meta_ac = NULL;
3718
3719         ret = ocfs2_calc_refcount_meta_credits(inode->i_sb,
3720                                                ref_ci, ref_root_bh,
3721                                                p_cluster, num_clusters,
3722                                                &ref_blocks, &credits);
3723         if (ret) {
3724                 mlog_errno(ret);
3725                 goto out;
3726         }
3727
3728         trace_ocfs2_add_refcount_flag(ref_blocks, credits);
3729
3730         if (ref_blocks) {
3731                 ret = ocfs2_reserve_new_metadata_blocks(OCFS2_SB(inode->i_sb),
3732                                                         ref_blocks, &meta_ac);
3733                 if (ret) {
3734                         mlog_errno(ret);
3735                         goto out;
3736                 }
3737         }
3738
3739         if (post)
3740                 credits += post->credits;
3741
3742         handle = ocfs2_start_trans(osb, credits);
3743         if (IS_ERR(handle)) {
3744                 ret = PTR_ERR(handle);
3745                 mlog_errno(ret);
3746                 goto out;
3747         }
3748
3749         ret = ocfs2_mark_extent_refcounted(inode, data_et, handle,
3750                                            cpos, num_clusters, p_cluster,
3751                                            meta_ac, dealloc);
3752         if (ret) {
3753                 mlog_errno(ret);
3754                 goto out_commit;
3755         }
3756
3757         ret = __ocfs2_increase_refcount(handle, ref_ci, ref_root_bh,
3758                                         p_cluster, num_clusters, 0,
3759                                         meta_ac, dealloc);
3760         if (ret) {
3761                 mlog_errno(ret);
3762                 goto out_commit;
3763         }
3764
3765         if (post && post->func) {
3766                 ret = post->func(inode, handle, post->para);
3767                 if (ret)
3768                         mlog_errno(ret);
3769         }
3770
3771 out_commit:
3772         ocfs2_commit_trans(osb, handle);
3773 out:
3774         if (meta_ac)
3775                 ocfs2_free_alloc_context(meta_ac);
3776         return ret;
3777 }
3778
3779 static int ocfs2_change_ctime(struct inode *inode,
3780                               struct buffer_head *di_bh)
3781 {
3782         int ret;
3783         handle_t *handle;
3784         struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
3785
3786         handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb),
3787                                    OCFS2_INODE_UPDATE_CREDITS);
3788         if (IS_ERR(handle)) {
3789                 ret = PTR_ERR(handle);
3790                 mlog_errno(ret);
3791                 goto out;
3792         }
3793
3794         ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
3795                                       OCFS2_JOURNAL_ACCESS_WRITE);
3796         if (ret) {
3797                 mlog_errno(ret);
3798                 goto out_commit;
3799         }
3800
3801         inode->i_ctime = CURRENT_TIME;
3802         di->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
3803         di->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
3804
3805         ocfs2_journal_dirty(handle, di_bh);
3806
3807 out_commit:
3808         ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
3809 out:
3810         return ret;
3811 }
3812
3813 static int ocfs2_attach_refcount_tree(struct inode *inode,
3814                                       struct buffer_head *di_bh)
3815 {
3816         int ret, data_changed = 0;
3817         struct buffer_head *ref_root_bh = NULL;
3818         struct ocfs2_inode_info *oi = OCFS2_I(inode);
3819         struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
3820         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
3821         struct ocfs2_refcount_tree *ref_tree;
3822         unsigned int ext_flags;
3823         loff_t size;
3824         u32 cpos, num_clusters, clusters, p_cluster;
3825         struct ocfs2_cached_dealloc_ctxt dealloc;
3826         struct ocfs2_extent_tree di_et;
3827
3828         ocfs2_init_dealloc_ctxt(&dealloc);
3829
3830         if (!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL)) {
3831                 ret = ocfs2_create_refcount_tree(inode, di_bh);
3832                 if (ret) {
3833                         mlog_errno(ret);
3834                         goto out;
3835                 }
3836         }
3837
3838         BUG_ON(!di->i_refcount_loc);
3839         ret = ocfs2_lock_refcount_tree(osb,
3840                                        le64_to_cpu(di->i_refcount_loc), 1,
3841                                        &ref_tree, &ref_root_bh);
3842         if (ret) {
3843                 mlog_errno(ret);
3844                 goto out;
3845         }
3846
3847         if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
3848                 goto attach_xattr;
3849
3850         ocfs2_init_dinode_extent_tree(&di_et, INODE_CACHE(inode), di_bh);
3851
3852         size = i_size_read(inode);
3853         clusters = ocfs2_clusters_for_bytes(inode->i_sb, size);
3854
3855         cpos = 0;
3856         while (cpos < clusters) {
3857                 ret = ocfs2_get_clusters(inode, cpos, &p_cluster,
3858                                          &num_clusters, &ext_flags);
3859                 if (ret) {
3860                         mlog_errno(ret);
3861                         goto unlock;
3862                 }
3863                 if (p_cluster && !(ext_flags & OCFS2_EXT_REFCOUNTED)) {
3864                         ret = ocfs2_add_refcount_flag(inode, &di_et,
3865                                                       &ref_tree->rf_ci,
3866                                                       ref_root_bh, cpos,
3867                                                       p_cluster, num_clusters,
3868                                                       &dealloc, NULL);
3869                         if (ret) {
3870                                 mlog_errno(ret);
3871                                 goto unlock;
3872                         }
3873
3874                         data_changed = 1;
3875                 }
3876                 cpos += num_clusters;
3877         }
3878
3879 attach_xattr:
3880         if (oi->ip_dyn_features & OCFS2_HAS_XATTR_FL) {
3881                 ret = ocfs2_xattr_attach_refcount_tree(inode, di_bh,
3882                                                        &ref_tree->rf_ci,
3883                                                        ref_root_bh,
3884                                                        &dealloc);
3885                 if (ret) {
3886                         mlog_errno(ret);
3887                         goto unlock;
3888                 }
3889         }
3890
3891         if (data_changed) {
3892                 ret = ocfs2_change_ctime(inode, di_bh);
3893                 if (ret)
3894                         mlog_errno(ret);
3895         }
3896
3897 unlock:
3898         ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
3899         brelse(ref_root_bh);
3900
3901         if (!ret && ocfs2_dealloc_has_cluster(&dealloc)) {
3902                 ocfs2_schedule_truncate_log_flush(osb, 1);
3903                 ocfs2_run_deallocs(osb, &dealloc);
3904         }
3905 out:
3906         /*
3907          * Empty the extent map so that we may get the right extent
3908          * record from the disk.
3909          */
3910         ocfs2_extent_map_trunc(inode, 0);
3911
3912         return ret;
3913 }
3914
3915 static int ocfs2_add_refcounted_extent(struct inode *inode,
3916                                    struct ocfs2_extent_tree *et,
3917                                    struct ocfs2_caching_info *ref_ci,
3918                                    struct buffer_head *ref_root_bh,
3919                                    u32 cpos, u32 p_cluster, u32 num_clusters,
3920                                    unsigned int ext_flags,
3921                                    struct ocfs2_cached_dealloc_ctxt *dealloc)
3922 {
3923         int ret;
3924         handle_t *handle;
3925         int credits = 0;
3926         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
3927         struct ocfs2_alloc_context *meta_ac = NULL;
3928
3929         ret = ocfs2_lock_refcount_allocators(inode->i_sb,
3930                                              p_cluster, num_clusters,
3931                                              et, ref_ci,
3932                                              ref_root_bh, &meta_ac,
3933                                              NULL, &credits);
3934         if (ret) {
3935                 mlog_errno(ret);
3936                 goto out;
3937         }
3938
3939         handle = ocfs2_start_trans(osb, credits);
3940         if (IS_ERR(handle)) {
3941                 ret = PTR_ERR(handle);
3942                 mlog_errno(ret);
3943                 goto out;
3944         }
3945
3946         ret = ocfs2_insert_extent(handle, et, cpos,
3947                         ocfs2_clusters_to_blocks(inode->i_sb, p_cluster),
3948                         num_clusters, ext_flags, meta_ac);
3949         if (ret) {
3950                 mlog_errno(ret);
3951                 goto out_commit;
3952         }
3953
3954         ret = ocfs2_increase_refcount(handle, ref_ci, ref_root_bh,
3955                                       p_cluster, num_clusters,
3956                                       meta_ac, dealloc);
3957         if (ret)
3958                 mlog_errno(ret);
3959
3960 out_commit:
3961         ocfs2_commit_trans(osb, handle);
3962 out:
3963         if (meta_ac)
3964                 ocfs2_free_alloc_context(meta_ac);
3965         return ret;
3966 }
3967
3968 static int ocfs2_duplicate_inline_data(struct inode *s_inode,
3969                                        struct buffer_head *s_bh,
3970                                        struct inode *t_inode,
3971                                        struct buffer_head *t_bh)
3972 {
3973         int ret;
3974         handle_t *handle;
3975         struct ocfs2_super *osb = OCFS2_SB(s_inode->i_sb);
3976         struct ocfs2_dinode *s_di = (struct ocfs2_dinode *)s_bh->b_data;
3977         struct ocfs2_dinode *t_di = (struct ocfs2_dinode *)t_bh->b_data;
3978
3979         BUG_ON(!(OCFS2_I(s_inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL));
3980
3981         handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
3982         if (IS_ERR(handle)) {
3983                 ret = PTR_ERR(handle);
3984                 mlog_errno(ret);
3985                 goto out;
3986         }
3987
3988         ret = ocfs2_journal_access_di(handle, INODE_CACHE(t_inode), t_bh,
3989                                       OCFS2_JOURNAL_ACCESS_WRITE);
3990         if (ret) {
3991                 mlog_errno(ret);
3992                 goto out_commit;
3993         }
3994
3995         t_di->id2.i_data.id_count = s_di->id2.i_data.id_count;
3996         memcpy(t_di->id2.i_data.id_data, s_di->id2.i_data.id_data,
3997                le16_to_cpu(s_di->id2.i_data.id_count));
3998         spin_lock(&OCFS2_I(t_inode)->ip_lock);
3999         OCFS2_I(t_inode)->ip_dyn_features |= OCFS2_INLINE_DATA_FL;
4000         t_di->i_dyn_features = cpu_to_le16(OCFS2_I(t_inode)->ip_dyn_features);
4001         spin_unlock(&OCFS2_I(t_inode)->ip_lock);
4002
4003         ocfs2_journal_dirty(handle, t_bh);
4004
4005 out_commit:
4006         ocfs2_commit_trans(osb, handle);
4007 out:
4008         return ret;
4009 }
4010
4011 static int ocfs2_duplicate_extent_list(struct inode *s_inode,
4012                                 struct inode *t_inode,
4013                                 struct buffer_head *t_bh,
4014                                 struct ocfs2_caching_info *ref_ci,
4015                                 struct buffer_head *ref_root_bh,
4016                                 struct ocfs2_cached_dealloc_ctxt *dealloc)
4017 {
4018         int ret = 0;
4019         u32 p_cluster, num_clusters, clusters, cpos;
4020         loff_t size;
4021         unsigned int ext_flags;
4022         struct ocfs2_extent_tree et;
4023
4024         ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(t_inode), t_bh);
4025
4026         size = i_size_read(s_inode);
4027         clusters = ocfs2_clusters_for_bytes(s_inode->i_sb, size);
4028
4029         cpos = 0;
4030         while (cpos < clusters) {
4031                 ret = ocfs2_get_clusters(s_inode, cpos, &p_cluster,
4032                                          &num_clusters, &ext_flags);
4033                 if (ret) {
4034                         mlog_errno(ret);
4035                         goto out;
4036                 }
4037                 if (p_cluster) {
4038                         ret = ocfs2_add_refcounted_extent(t_inode, &et,
4039                                                           ref_ci, ref_root_bh,
4040                                                           cpos, p_cluster,
4041                                                           num_clusters,
4042                                                           ext_flags,
4043                                                           dealloc);
4044                         if (ret) {
4045                                 mlog_errno(ret);
4046                                 goto out;
4047                         }
4048                 }
4049
4050                 cpos += num_clusters;
4051         }
4052
4053 out:
4054         return ret;
4055 }
4056
4057 /*
4058  * change the new file's attributes to the src.
4059  *
4060  * reflink creates a snapshot of a file, that means the attributes
4061  * must be identical except for three exceptions - nlink, ino, and ctime.
4062  */
4063 static int ocfs2_complete_reflink(struct inode *s_inode,
4064                                   struct buffer_head *s_bh,
4065                                   struct inode *t_inode,
4066                                   struct buffer_head *t_bh,
4067                                   bool preserve)
4068 {
4069         int ret;
4070         handle_t *handle;
4071         struct ocfs2_dinode *s_di = (struct ocfs2_dinode *)s_bh->b_data;
4072         struct ocfs2_dinode *di = (struct ocfs2_dinode *)t_bh->b_data;
4073         loff_t size = i_size_read(s_inode);
4074
4075         handle = ocfs2_start_trans(OCFS2_SB(t_inode->i_sb),
4076                                    OCFS2_INODE_UPDATE_CREDITS);
4077         if (IS_ERR(handle)) {
4078                 ret = PTR_ERR(handle);
4079                 mlog_errno(ret);
4080                 return ret;
4081         }
4082
4083         ret = ocfs2_journal_access_di(handle, INODE_CACHE(t_inode), t_bh,
4084                                       OCFS2_JOURNAL_ACCESS_WRITE);
4085         if (ret) {
4086                 mlog_errno(ret);
4087                 goto out_commit;
4088         }
4089
4090         spin_lock(&OCFS2_I(t_inode)->ip_lock);
4091         OCFS2_I(t_inode)->ip_clusters = OCFS2_I(s_inode)->ip_clusters;
4092         OCFS2_I(t_inode)->ip_attr = OCFS2_I(s_inode)->ip_attr;
4093         OCFS2_I(t_inode)->ip_dyn_features = OCFS2_I(s_inode)->ip_dyn_features;
4094         spin_unlock(&OCFS2_I(t_inode)->ip_lock);
4095         i_size_write(t_inode, size);
4096         t_inode->i_blocks = s_inode->i_blocks;
4097
4098         di->i_xattr_inline_size = s_di->i_xattr_inline_size;
4099         di->i_clusters = s_di->i_clusters;
4100         di->i_size = s_di->i_size;
4101         di->i_dyn_features = s_di->i_dyn_features;
4102         di->i_attr = s_di->i_attr;
4103
4104         if (preserve) {
4105                 t_inode->i_uid = s_inode->i_uid;
4106                 t_inode->i_gid = s_inode->i_gid;
4107                 t_inode->i_mode = s_inode->i_mode;
4108                 di->i_uid = s_di->i_uid;
4109                 di->i_gid = s_di->i_gid;
4110                 di->i_mode = s_di->i_mode;
4111
4112                 /*
4113                  * update time.
4114                  * we want mtime to appear identical to the source and
4115                  * update ctime.
4116                  */
4117                 t_inode->i_ctime = CURRENT_TIME;
4118
4119                 di->i_ctime = cpu_to_le64(t_inode->i_ctime.tv_sec);
4120                 di->i_ctime_nsec = cpu_to_le32(t_inode->i_ctime.tv_nsec);
4121
4122                 t_inode->i_mtime = s_inode->i_mtime;
4123                 di->i_mtime = s_di->i_mtime;
4124                 di->i_mtime_nsec = s_di->i_mtime_nsec;
4125         }
4126
4127         ocfs2_journal_dirty(handle, t_bh);
4128
4129 out_commit:
4130         ocfs2_commit_trans(OCFS2_SB(t_inode->i_sb), handle);
4131         return ret;
4132 }
4133
4134 static int ocfs2_create_reflink_node(struct inode *s_inode,
4135                                      struct buffer_head *s_bh,
4136                                      struct inode *t_inode,
4137                                      struct buffer_head *t_bh,
4138                                      bool preserve)
4139 {
4140         int ret;
4141         struct buffer_head *ref_root_bh = NULL;
4142         struct ocfs2_cached_dealloc_ctxt dealloc;
4143         struct ocfs2_super *osb = OCFS2_SB(s_inode->i_sb);
4144         struct ocfs2_refcount_block *rb;
4145         struct ocfs2_dinode *di = (struct ocfs2_dinode *)s_bh->b_data;
4146         struct ocfs2_refcount_tree *ref_tree;
4147
4148         ocfs2_init_dealloc_ctxt(&dealloc);
4149
4150         ret = ocfs2_set_refcount_tree(t_inode, t_bh,
4151                                       le64_to_cpu(di->i_refcount_loc));
4152         if (ret) {
4153                 mlog_errno(ret);
4154                 goto out;
4155         }
4156
4157         if (OCFS2_I(s_inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
4158                 ret = ocfs2_duplicate_inline_data(s_inode, s_bh,
4159                                                   t_inode, t_bh);
4160                 if (ret)
4161                         mlog_errno(ret);
4162                 goto out;
4163         }
4164
4165         ret = ocfs2_lock_refcount_tree(osb, le64_to_cpu(di->i_refcount_loc),
4166                                        1, &ref_tree, &ref_root_bh);
4167         if (ret) {
4168                 mlog_errno(ret);
4169                 goto out;
4170         }
4171         rb = (struct ocfs2_refcount_block *)ref_root_bh->b_data;
4172
4173         ret = ocfs2_duplicate_extent_list(s_inode, t_inode, t_bh,
4174                                           &ref_tree->rf_ci, ref_root_bh,
4175                                           &dealloc);
4176         if (ret) {
4177                 mlog_errno(ret);
4178                 goto out_unlock_refcount;
4179         }
4180
4181 out_unlock_refcount:
4182         ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
4183         brelse(ref_root_bh);
4184 out:
4185         if (ocfs2_dealloc_has_cluster(&dealloc)) {
4186                 ocfs2_schedule_truncate_log_flush(osb, 1);
4187                 ocfs2_run_deallocs(osb, &dealloc);
4188         }
4189
4190         return ret;
4191 }
4192
4193 static int __ocfs2_reflink(struct dentry *old_dentry,
4194                            struct buffer_head *old_bh,
4195                            struct inode *new_inode,
4196                            bool preserve)
4197 {
4198         int ret;
4199         struct inode *inode = old_dentry->d_inode;
4200         struct buffer_head *new_bh = NULL;
4201
4202         if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE) {
4203                 ret = -EINVAL;
4204                 mlog_errno(ret);
4205                 goto out;
4206         }
4207
4208         ret = filemap_fdatawrite(inode->i_mapping);
4209         if (ret) {
4210                 mlog_errno(ret);
4211                 goto out;
4212         }
4213
4214         ret = ocfs2_attach_refcount_tree(inode, old_bh);
4215         if (ret) {
4216                 mlog_errno(ret);
4217                 goto out;
4218         }
4219
4220         mutex_lock_nested(&new_inode->i_mutex, I_MUTEX_CHILD);
4221         ret = ocfs2_inode_lock_nested(new_inode, &new_bh, 1,
4222                                       OI_LS_REFLINK_TARGET);
4223         if (ret) {
4224                 mlog_errno(ret);
4225                 goto out_unlock;
4226         }
4227
4228         ret = ocfs2_create_reflink_node(inode, old_bh,
4229                                         new_inode, new_bh, preserve);
4230         if (ret) {
4231                 mlog_errno(ret);
4232                 goto inode_unlock;
4233         }
4234
4235         if (OCFS2_I(inode)->ip_dyn_features & OCFS2_HAS_XATTR_FL) {
4236                 ret = ocfs2_reflink_xattrs(inode, old_bh,
4237                                            new_inode, new_bh,
4238                                            preserve);
4239                 if (ret) {
4240                         mlog_errno(ret);
4241                         goto inode_unlock;
4242                 }
4243         }
4244
4245         ret = ocfs2_complete_reflink(inode, old_bh,
4246                                      new_inode, new_bh, preserve);
4247         if (ret)
4248                 mlog_errno(ret);
4249
4250 inode_unlock:
4251         ocfs2_inode_unlock(new_inode, 1);
4252         brelse(new_bh);
4253 out_unlock:
4254         mutex_unlock(&new_inode->i_mutex);
4255 out:
4256         if (!ret) {
4257                 ret = filemap_fdatawait(inode->i_mapping);
4258                 if (ret)
4259                         mlog_errno(ret);
4260         }
4261         return ret;
4262 }
4263
4264 static int ocfs2_reflink(struct dentry *old_dentry, struct inode *dir,
4265                          struct dentry *new_dentry, bool preserve)
4266 {
4267         int error;
4268         struct inode *inode = old_dentry->d_inode;
4269         struct buffer_head *old_bh = NULL;
4270         struct inode *new_orphan_inode = NULL;
4271         struct posix_acl *default_acl, *acl;
4272         umode_t mode;
4273
4274         if (!ocfs2_refcount_tree(OCFS2_SB(inode->i_sb)))
4275                 return -EOPNOTSUPP;
4276
4277         mode = inode->i_mode;
4278         error = posix_acl_create(dir, &mode, &default_acl, &acl);
4279         if (error) {
4280                 mlog_errno(error);
4281                 goto out;
4282         }
4283
4284         error = ocfs2_create_inode_in_orphan(dir, mode,
4285                                              &new_orphan_inode);
4286         if (error) {
4287                 mlog_errno(error);
4288                 goto out;
4289         }
4290
4291         error = ocfs2_rw_lock(inode, 1);
4292         if (error) {
4293                 mlog_errno(error);
4294                 goto out;
4295         }
4296
4297         error = ocfs2_inode_lock(inode, &old_bh, 1);
4298         if (error) {
4299                 mlog_errno(error);
4300                 ocfs2_rw_unlock(inode, 1);
4301                 goto out;
4302         }
4303
4304         down_write(&OCFS2_I(inode)->ip_xattr_sem);
4305         down_write(&OCFS2_I(inode)->ip_alloc_sem);
4306         error = __ocfs2_reflink(old_dentry, old_bh,
4307                                 new_orphan_inode, preserve);
4308         up_write(&OCFS2_I(inode)->ip_alloc_sem);
4309         up_write(&OCFS2_I(inode)->ip_xattr_sem);
4310
4311         ocfs2_inode_unlock(inode, 1);
4312         ocfs2_rw_unlock(inode, 1);
4313         brelse(old_bh);
4314
4315         if (error) {
4316                 mlog_errno(error);
4317                 goto out;
4318         }
4319
4320         /* If the security isn't preserved, we need to re-initialize them. */
4321         if (!preserve) {
4322                 error = ocfs2_init_security_and_acl(dir, new_orphan_inode,
4323                                                     &new_dentry->d_name,
4324                                                     default_acl, acl);
4325                 if (error)
4326                         mlog_errno(error);
4327         }
4328 out:
4329         if (default_acl)
4330                 posix_acl_release(default_acl);
4331         if (acl)
4332                 posix_acl_release(acl);
4333         if (!error) {
4334                 error = ocfs2_mv_orphaned_inode_to_new(dir, new_orphan_inode,
4335                                                        new_dentry);
4336                 if (error)
4337                         mlog_errno(error);
4338         }
4339
4340         if (new_orphan_inode) {
4341                 /*
4342                  * We need to open_unlock the inode no matter whether we
4343                  * succeed or not, so that other nodes can delete it later.
4344                  */
4345                 ocfs2_open_unlock(new_orphan_inode);
4346                 if (error)
4347                         iput(new_orphan_inode);
4348         }
4349
4350         return error;
4351 }
4352
4353 /*
4354  * Below here are the bits used by OCFS2_IOC_REFLINK() to fake
4355  * sys_reflink().  This will go away when vfs_reflink() exists in
4356  * fs/namei.c.
4357  */
4358
4359 /* copied from may_create in VFS. */
4360 static inline int ocfs2_may_create(struct inode *dir, struct dentry *child)
4361 {
4362         if (child->d_inode)
4363                 return -EEXIST;
4364         if (IS_DEADDIR(dir))
4365                 return -ENOENT;
4366         return inode_permission(dir, MAY_WRITE | MAY_EXEC);
4367 }
4368
4369 /**
4370  * ocfs2_vfs_reflink - Create a reference-counted link
4371  *
4372  * @old_dentry:        source dentry + inode
4373  * @dir:       directory to create the target
4374  * @new_dentry:        target dentry
4375  * @preserve:  if true, preserve all file attributes
4376  */
4377 static int ocfs2_vfs_reflink(struct dentry *old_dentry, struct inode *dir,
4378                              struct dentry *new_dentry, bool preserve)
4379 {
4380         struct inode *inode = old_dentry->d_inode;
4381         int error;
4382
4383         if (!inode)
4384                 return -ENOENT;
4385
4386         error = ocfs2_may_create(dir, new_dentry);
4387         if (error)
4388                 return error;
4389
4390         if (dir->i_sb != inode->i_sb)
4391                 return -EXDEV;
4392
4393         /*
4394          * A reflink to an append-only or immutable file cannot be created.
4395          */
4396         if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
4397                 return -EPERM;
4398
4399         /* Only regular files can be reflinked. */
4400         if (!S_ISREG(inode->i_mode))
4401                 return -EPERM;
4402
4403         /*
4404          * If the caller wants to preserve ownership, they require the
4405          * rights to do so.
4406          */
4407         if (preserve) {
4408                 if (!uid_eq(current_fsuid(), inode->i_uid) && !capable(CAP_CHOWN))
4409                         return -EPERM;
4410                 if (!in_group_p(inode->i_gid) && !capable(CAP_CHOWN))
4411                         return -EPERM;
4412         }
4413
4414         /*
4415          * If the caller is modifying any aspect of the attributes, they
4416          * are not creating a snapshot.  They need read permission on the
4417          * file.
4418          */
4419         if (!preserve) {
4420                 error = inode_permission(inode, MAY_READ);
4421                 if (error)
4422                         return error;
4423         }
4424
4425         mutex_lock(&inode->i_mutex);
4426         dquot_initialize(dir);
4427         error = ocfs2_reflink(old_dentry, dir, new_dentry, preserve);
4428         mutex_unlock(&inode->i_mutex);
4429         if (!error)
4430                 fsnotify_create(dir, new_dentry);
4431         return error;
4432 }
4433 /*
4434  * Most codes are copied from sys_linkat.
4435  */
4436 int ocfs2_reflink_ioctl(struct inode *inode,
4437                         const char __user *oldname,
4438                         const char __user *newname,
4439                         bool preserve)
4440 {
4441         struct dentry *new_dentry;
4442         struct path old_path, new_path;
4443         int error;
4444
4445         if (!ocfs2_refcount_tree(OCFS2_SB(inode->i_sb)))
4446                 return -EOPNOTSUPP;
4447
4448         error = user_path_at(AT_FDCWD, oldname, 0, &old_path);
4449         if (error) {
4450                 mlog_errno(error);
4451                 return error;
4452         }
4453
4454         new_dentry = user_path_create(AT_FDCWD, newname, &new_path, 0);
4455         error = PTR_ERR(new_dentry);
4456         if (IS_ERR(new_dentry)) {
4457                 mlog_errno(error);
4458                 goto out;
4459         }
4460
4461         error = -EXDEV;
4462         if (old_path.mnt != new_path.mnt) {
4463                 mlog_errno(error);
4464                 goto out_dput;
4465         }
4466
4467         error = ocfs2_vfs_reflink(old_path.dentry,
4468                                   new_path.dentry->d_inode,
4469                                   new_dentry, preserve);
4470 out_dput:
4471         done_path_create(&new_path, new_dentry);
4472 out:
4473         path_put(&old_path);
4474
4475         return error;
4476 }