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 #define MLOG_MASK_PREFIX ML_REFCOUNT
  20 #include <cluster/masklog.h>
  21 #include "ocfs2.h"
  22 #include "inode.h"
  23 #include "alloc.h"
  24 #include "suballoc.h"
  25 #include "journal.h"
  26 #include "uptodate.h"
  27 #include "super.h"
  28 #include "buffer_head_io.h"
  29 #include "blockcheck.h"
  30 #include "refcounttree.h"
  31 #include "sysfile.h"
  32 #include "dlmglue.h"
  33 #include "extent_map.h"
  34 #include "aops.h"
  35 #include "xattr.h"
  36 #include "namei.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
  50 struct ocfs2_cow_context {
  51         struct inode *inode;
  52         u32 cow_start;
  53         u32 cow_len;
  54         struct ocfs2_extent_tree data_et;
  55         struct ocfs2_refcount_tree *ref_tree;
  56         struct buffer_head *ref_root_bh;
  57         struct ocfs2_alloc_context *meta_ac;
  58         struct ocfs2_alloc_context *data_ac;
  59         struct ocfs2_cached_dealloc_ctxt dealloc;
  60         void *cow_object;
  61         struct ocfs2_post_refcount *post_refcount;
  62         int extra_credits;
  63         int (*get_clusters)(struct ocfs2_cow_context *context,
  64                             u32 v_cluster, u32 *p_cluster,
  65                             u32 *num_clusters,
  66                             unsigned int *extent_flags);
  67         int (*cow_duplicate_clusters)(handle_t *handle,
  68                                       struct ocfs2_cow_context *context,
  69                                       u32 cpos, u32 old_cluster,
  70                                       u32 new_cluster, u32 new_len);
  71 };
  72
  73 static inline struct ocfs2_refcount_tree *
  74 cache_info_to_refcount(struct ocfs2_caching_info *ci)
  75 {
  76         return container_of(ci, struct ocfs2_refcount_tree, rf_ci);
  77 }
  78
  79 static int ocfs2_validate_refcount_block(struct super_block *sb,
  80                                          struct buffer_head *bh)
  81 {
  82         int rc;
  83         struct ocfs2_refcount_block *rb =
  84                 (struct ocfs2_refcount_block *)bh->b_data;
  85
  86         mlog(0, "Validating refcount block %llu\n",
  87              (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                 mlog(0, "Purge tree %llu\n",
 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 first_blkno;
 574
 575         BUG_ON(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL);
 576
 577         mlog(0, "create tree for inode %lu\n", inode->i_ino);
 578
 579         ret = ocfs2_reserve_new_metadata_blocks(osb, 1, &meta_ac);
 580         if (ret) {
 581                 mlog_errno(ret);
 582                 goto out;
 583         }
 584
 585         handle = ocfs2_start_trans(osb, OCFS2_REFCOUNT_TREE_CREATE_CREDITS);
 586         if (IS_ERR(handle)) {
 587                 ret = PTR_ERR(handle);
 588                 mlog_errno(ret);
 589                 goto out;
 590         }
 591
 592         ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
 593                                       OCFS2_JOURNAL_ACCESS_WRITE);
 594         if (ret) {
 595                 mlog_errno(ret);
 596                 goto out_commit;
 597         }
 598
 599         ret = ocfs2_claim_metadata(osb, handle, meta_ac, 1,
 600                                    &suballoc_bit_start, &num_got,
 601                                    &first_blkno);
 602         if (ret) {
 603                 mlog_errno(ret);
 604                 goto out_commit;
 605         }
 606
 607         new_tree = ocfs2_allocate_refcount_tree(osb, first_blkno);
 608         if (!new_tree) {
 609                 ret = -ENOMEM;
 610                 mlog_errno(ret);
 611                 goto out_commit;
 612         }
 613
 614         new_bh = sb_getblk(inode->i_sb, first_blkno);
 615         ocfs2_set_new_buffer_uptodate(&new_tree->rf_ci, new_bh);
 616
 617         ret = ocfs2_journal_access_rb(handle, &new_tree->rf_ci, new_bh,
 618                                       OCFS2_JOURNAL_ACCESS_CREATE);
 619         if (ret) {
 620                 mlog_errno(ret);
 621                 goto out_commit;
 622         }
 623
 624         /* Initialize ocfs2_refcount_block. */
 625         rb = (struct ocfs2_refcount_block *)new_bh->b_data;
 626         memset(rb, 0, inode->i_sb->s_blocksize);
 627         strcpy((void *)rb, OCFS2_REFCOUNT_BLOCK_SIGNATURE);
 628         rb->rf_suballoc_slot = cpu_to_le16(meta_ac->ac_alloc_slot);
 629         rb->rf_suballoc_bit = cpu_to_le16(suballoc_bit_start);
 630         rb->rf_fs_generation = cpu_to_le32(osb->fs_generation);
 631         rb->rf_blkno = cpu_to_le64(first_blkno);
 632         rb->rf_count = cpu_to_le32(1);
 633         rb->rf_records.rl_count =
 634                         cpu_to_le16(ocfs2_refcount_recs_per_rb(osb->sb));
 635         spin_lock(&osb->osb_lock);
 636         rb->rf_generation = osb->s_next_generation++;
 637         spin_unlock(&osb->osb_lock);
 638
 639         ocfs2_journal_dirty(handle, new_bh);
 640
 641         spin_lock(&oi->ip_lock);
 642         oi->ip_dyn_features |= OCFS2_HAS_REFCOUNT_FL;
 643         di->i_dyn_features = cpu_to_le16(oi->ip_dyn_features);
 644         di->i_refcount_loc = cpu_to_le64(first_blkno);
 645         spin_unlock(&oi->ip_lock);
 646
 647         mlog(0, "created tree for inode %lu, refblock %llu\n",
 648              inode->i_ino, (unsigned long long)first_blkno);
 649
 650         ocfs2_journal_dirty(handle, di_bh);
 651
 652         /*
 653          * We have to init the tree lock here since it will use
 654          * the generation number to create it.
 655          */
 656         new_tree->rf_generation = le32_to_cpu(rb->rf_generation);
 657         ocfs2_init_refcount_tree_lock(osb, new_tree, first_blkno,
 658                                       new_tree->rf_generation);
 659
 660         spin_lock(&osb->osb_lock);
 661         tree = ocfs2_find_refcount_tree(osb, first_blkno);
 662
 663         /*
 664          * We've just created a new refcount tree in this block.  If
 665          * we found a refcount tree on the ocfs2_super, it must be
 666          * one we just deleted.  We free the old tree before
 667          * inserting the new tree.
 668          */
 669         BUG_ON(tree && tree->rf_generation == new_tree->rf_generation);
 670         if (tree)
 671                 ocfs2_erase_refcount_tree_from_list_no_lock(osb, tree);
 672         ocfs2_insert_refcount_tree(osb, new_tree);
 673         spin_unlock(&osb->osb_lock);
 674         new_tree = NULL;
 675         if (tree)
 676                 ocfs2_refcount_tree_put(tree);
 677
 678 out_commit:
 679         ocfs2_commit_trans(osb, handle);
 680
 681 out:
 682         if (new_tree) {
 683                 ocfs2_metadata_cache_exit(&new_tree->rf_ci);
 684                 kfree(new_tree);
 685         }
 686
 687         brelse(new_bh);
 688         if (meta_ac)
 689                 ocfs2_free_alloc_context(meta_ac);
 690
 691         return ret;
 692 }
 693
 694 static int ocfs2_set_refcount_tree(struct inode *inode,
 695                                    struct buffer_head *di_bh,
 696                                    u64 refcount_loc)
 697 {
 698         int ret;
 699         handle_t *handle = NULL;
 700         struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
 701         struct ocfs2_inode_info *oi = OCFS2_I(inode);
 702         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 703         struct buffer_head *ref_root_bh = NULL;
 704         struct ocfs2_refcount_block *rb;
 705         struct ocfs2_refcount_tree *ref_tree;
 706
 707         BUG_ON(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL);
 708
 709         ret = ocfs2_lock_refcount_tree(osb, refcount_loc, 1,
 710                                        &ref_tree, &ref_root_bh);
 711         if (ret) {
 712                 mlog_errno(ret);
 713                 return ret;
 714         }
 715
 716         handle = ocfs2_start_trans(osb, OCFS2_REFCOUNT_TREE_SET_CREDITS);
 717         if (IS_ERR(handle)) {
 718                 ret = PTR_ERR(handle);
 719                 mlog_errno(ret);
 720                 goto out;
 721         }
 722
 723         ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
 724                                       OCFS2_JOURNAL_ACCESS_WRITE);
 725         if (ret) {
 726                 mlog_errno(ret);
 727                 goto out_commit;
 728         }
 729
 730         ret = ocfs2_journal_access_rb(handle, &ref_tree->rf_ci, ref_root_bh,
 731                                       OCFS2_JOURNAL_ACCESS_WRITE);
 732         if (ret) {
 733                 mlog_errno(ret);
 734                 goto out_commit;
 735         }
 736
 737         rb = (struct ocfs2_refcount_block *)ref_root_bh->b_data;
 738         le32_add_cpu(&rb->rf_count, 1);
 739
 740         ocfs2_journal_dirty(handle, ref_root_bh);
 741
 742         spin_lock(&oi->ip_lock);
 743         oi->ip_dyn_features |= OCFS2_HAS_REFCOUNT_FL;
 744         di->i_dyn_features = cpu_to_le16(oi->ip_dyn_features);
 745         di->i_refcount_loc = cpu_to_le64(refcount_loc);
 746         spin_unlock(&oi->ip_lock);
 747         ocfs2_journal_dirty(handle, di_bh);
 748
 749 out_commit:
 750         ocfs2_commit_trans(osb, handle);
 751 out:
 752         ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
 753         brelse(ref_root_bh);
 754
 755         return ret;
 756 }
 757
 758 int ocfs2_remove_refcount_tree(struct inode *inode, struct buffer_head *di_bh)
 759 {
 760         int ret, delete_tree = 0;
 761         handle_t *handle = NULL;
 762         struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
 763         struct ocfs2_inode_info *oi = OCFS2_I(inode);
 764         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 765         struct ocfs2_refcount_block *rb;
 766         struct inode *alloc_inode = NULL;
 767         struct buffer_head *alloc_bh = NULL;
 768         struct buffer_head *blk_bh = NULL;
 769         struct ocfs2_refcount_tree *ref_tree;
 770         int credits = OCFS2_REFCOUNT_TREE_REMOVE_CREDITS;
 771         u64 blk = 0, bg_blkno = 0, ref_blkno = le64_to_cpu(di->i_refcount_loc);
 772         u16 bit = 0;
 773
 774         if (!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL))
 775                 return 0;
 776
 777         BUG_ON(!ref_blkno);
 778         ret = ocfs2_lock_refcount_tree(osb, ref_blkno, 1, &ref_tree, &blk_bh);
 779         if (ret) {
 780                 mlog_errno(ret);
 781                 return ret;
 782         }
 783
 784         rb = (struct ocfs2_refcount_block *)blk_bh->b_data;
 785
 786         /*
 787          * If we are the last user, we need to free the block.
 788          * So lock the allocator ahead.
 789          */
 790         if (le32_to_cpu(rb->rf_count) == 1) {
 791                 blk = le64_to_cpu(rb->rf_blkno);
 792                 bit = le16_to_cpu(rb->rf_suballoc_bit);
 793                 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
 794
 795                 alloc_inode = ocfs2_get_system_file_inode(osb,
 796                                         EXTENT_ALLOC_SYSTEM_INODE,
 797                                         le16_to_cpu(rb->rf_suballoc_slot));
 798                 if (!alloc_inode) {
 799                         ret = -ENOMEM;
 800                         mlog_errno(ret);
 801                         goto out;
 802                 }
 803                 mutex_lock(&alloc_inode->i_mutex);
 804
 805                 ret = ocfs2_inode_lock(alloc_inode, &alloc_bh, 1);
 806                 if (ret) {
 807                         mlog_errno(ret);
 808                         goto out_mutex;
 809                 }
 810
 811                 credits += OCFS2_SUBALLOC_FREE;
 812         }
 813
 814         handle = ocfs2_start_trans(osb, credits);
 815         if (IS_ERR(handle)) {
 816                 ret = PTR_ERR(handle);
 817                 mlog_errno(ret);
 818                 goto out_unlock;
 819         }
 820
 821         ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
 822                                       OCFS2_JOURNAL_ACCESS_WRITE);
 823         if (ret) {
 824                 mlog_errno(ret);
 825                 goto out_commit;
 826         }
 827
 828         ret = ocfs2_journal_access_rb(handle, &ref_tree->rf_ci, blk_bh,
 829                                       OCFS2_JOURNAL_ACCESS_WRITE);
 830         if (ret) {
 831                 mlog_errno(ret);
 832                 goto out_commit;
 833         }
 834
 835         spin_lock(&oi->ip_lock);
 836         oi->ip_dyn_features &= ~OCFS2_HAS_REFCOUNT_FL;
 837         di->i_dyn_features = cpu_to_le16(oi->ip_dyn_features);
 838         di->i_refcount_loc = 0;
 839         spin_unlock(&oi->ip_lock);
 840         ocfs2_journal_dirty(handle, di_bh);
 841
 842         le32_add_cpu(&rb->rf_count , -1);
 843         ocfs2_journal_dirty(handle, blk_bh);
 844
 845         if (!rb->rf_count) {
 846                 delete_tree = 1;
 847                 ocfs2_erase_refcount_tree_from_list(osb, ref_tree);
 848                 ret = ocfs2_free_suballoc_bits(handle, alloc_inode,
 849                                                alloc_bh, bit, bg_blkno, 1);
 850                 if (ret)
 851                         mlog_errno(ret);
 852         }
 853
 854 out_commit:
 855         ocfs2_commit_trans(osb, handle);
 856 out_unlock:
 857         if (alloc_inode) {
 858                 ocfs2_inode_unlock(alloc_inode, 1);
 859                 brelse(alloc_bh);
 860         }
 861 out_mutex:
 862         if (alloc_inode) {
 863                 mutex_unlock(&alloc_inode->i_mutex);
 864                 iput(alloc_inode);
 865         }
 866 out:
 867         ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
 868         if (delete_tree)
 869                 ocfs2_refcount_tree_put(ref_tree);
 870         brelse(blk_bh);
 871
 872         return ret;
 873 }
 874
 875 static void ocfs2_find_refcount_rec_in_rl(struct ocfs2_caching_info *ci,
 876                                           struct buffer_head *ref_leaf_bh,
 877                                           u64 cpos, unsigned int len,
 878                                           struct ocfs2_refcount_rec *ret_rec,
 879                                           int *index)
 880 {
 881         int i = 0;
 882         struct ocfs2_refcount_block *rb =
 883                 (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
 884         struct ocfs2_refcount_rec *rec = NULL;
 885
 886         for (; i < le16_to_cpu(rb->rf_records.rl_used); i++) {
 887                 rec = &rb->rf_records.rl_recs[i];
 888
 889                 if (le64_to_cpu(rec->r_cpos) +
 890                     le32_to_cpu(rec->r_clusters) <= cpos)
 891                         continue;
 892                 else if (le64_to_cpu(rec->r_cpos) > cpos)
 893                         break;
 894
 895                 /* ok, cpos fail in this rec. Just return. */
 896                 if (ret_rec)
 897                         *ret_rec = *rec;
 898                 goto out;
 899         }
 900
 901         if (ret_rec) {
 902                 /* We meet with a hole here, so fake the rec. */
 903                 ret_rec->r_cpos = cpu_to_le64(cpos);
 904                 ret_rec->r_refcount = 0;
 905                 if (i < le16_to_cpu(rb->rf_records.rl_used) &&
 906                     le64_to_cpu(rec->r_cpos) < cpos + len)
 907                         ret_rec->r_clusters =
 908                                 cpu_to_le32(le64_to_cpu(rec->r_cpos) - cpos);
 909                 else
 910                         ret_rec->r_clusters = cpu_to_le32(len);
 911         }
 912
 913 out:
 914         *index = i;
 915 }
 916
 917 /*
 918  * Try to remove refcount tree. The mechanism is:
 919  * 1) Check whether i_clusters == 0, if no, exit.
 920  * 2) check whether we have i_xattr_loc in dinode. if yes, exit.
 921  * 3) Check whether we have inline xattr stored outside, if yes, exit.
 922  * 4) Remove the tree.
 923  */
 924 int ocfs2_try_remove_refcount_tree(struct inode *inode,
 925                                    struct buffer_head *di_bh)
 926 {
 927         int ret;
 928         struct ocfs2_inode_info *oi = OCFS2_I(inode);
 929         struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
 930
 931         down_write(&oi->ip_xattr_sem);
 932         down_write(&oi->ip_alloc_sem);
 933
 934         if (oi->ip_clusters)
 935                 goto out;
 936
 937         if ((oi->ip_dyn_features & OCFS2_HAS_XATTR_FL) && di->i_xattr_loc)
 938                 goto out;
 939
 940         if (oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL &&
 941             ocfs2_has_inline_xattr_value_outside(inode, di))
 942                 goto out;
 943
 944         ret = ocfs2_remove_refcount_tree(inode, di_bh);
 945         if (ret)
 946                 mlog_errno(ret);
 947 out:
 948         up_write(&oi->ip_alloc_sem);
 949         up_write(&oi->ip_xattr_sem);
 950         return 0;
 951 }
 952
 953 /*
 954  * Find the end range for a leaf refcount block indicated by
 955  * el->l_recs[index].e_blkno.
 956  */
 957 static int ocfs2_get_refcount_cpos_end(struct ocfs2_caching_info *ci,
 958                                        struct buffer_head *ref_root_bh,
 959                                        struct ocfs2_extent_block *eb,
 960                                        struct ocfs2_extent_list *el,
 961                                        int index,  u32 *cpos_end)
 962 {
 963         int ret, i, subtree_root;
 964         u32 cpos;
 965         u64 blkno;
 966         struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
 967         struct ocfs2_path *left_path = NULL, *right_path = NULL;
 968         struct ocfs2_extent_tree et;
 969         struct ocfs2_extent_list *tmp_el;
 970
 971         if (index < le16_to_cpu(el->l_next_free_rec) - 1) {
 972                 /*
 973                  * We have a extent rec after index, so just use the e_cpos
 974                  * of the next extent rec.
 975                  */
 976                 *cpos_end = le32_to_cpu(el->l_recs[index+1].e_cpos);
 977                 return 0;
 978         }
 979
 980         if (!eb || (eb && !eb->h_next_leaf_blk)) {
 981                 /*
 982                  * We are the last extent rec, so any high cpos should
 983                  * be stored in this leaf refcount block.
 984                  */
 985                 *cpos_end = UINT_MAX;
 986                 return 0;
 987         }
 988
 989         /*
 990          * If the extent block isn't the last one, we have to find
 991          * the subtree root between this extent block and the next
 992          * leaf extent block and get the corresponding e_cpos from
 993          * the subroot. Otherwise we may corrupt the b-tree.
 994          */
 995         ocfs2_init_refcount_extent_tree(&et, ci, ref_root_bh);
 996
 997         left_path = ocfs2_new_path_from_et(&et);
 998         if (!left_path) {
 999                 ret = -ENOMEM;
1000                 mlog_errno(ret);
1001                 goto out;
1002         }
1003
1004         cpos = le32_to_cpu(eb->h_list.l_recs[index].e_cpos);
1005         ret = ocfs2_find_path(ci, left_path, cpos);
1006         if (ret) {
1007                 mlog_errno(ret);
1008                 goto out;
1009         }
1010
1011         right_path = ocfs2_new_path_from_path(left_path);
1012         if (!right_path) {
1013                 ret = -ENOMEM;
1014                 mlog_errno(ret);
1015                 goto out;
1016         }
1017
1018         ret = ocfs2_find_cpos_for_right_leaf(sb, left_path, &cpos);
1019         if (ret) {
1020                 mlog_errno(ret);
1021                 goto out;
1022         }
1023
1024         ret = ocfs2_find_path(ci, right_path, cpos);
1025         if (ret) {
1026                 mlog_errno(ret);
1027                 goto out;
1028         }
1029
1030         subtree_root = ocfs2_find_subtree_root(&et, left_path,
1031                                                right_path);
1032
1033         tmp_el = left_path->p_node[subtree_root].el;
1034         blkno = left_path->p_node[subtree_root+1].bh->b_blocknr;
1035         for (i = 0; i < le32_to_cpu(tmp_el->l_next_free_rec); i++) {
1036                 if (le64_to_cpu(tmp_el->l_recs[i].e_blkno) == blkno) {
1037                         *cpos_end = le32_to_cpu(tmp_el->l_recs[i+1].e_cpos);
1038                         break;
1039                 }
1040         }
1041
1042         BUG_ON(i == le32_to_cpu(tmp_el->l_next_free_rec));
1043
1044 out:
1045         ocfs2_free_path(left_path);
1046         ocfs2_free_path(right_path);
1047         return ret;
1048 }
1049
1050 /*
1051  * Given a cpos and len, try to find the refcount record which contains cpos.
1052  * 1. If cpos can be found in one refcount record, return the record.
1053  * 2. If cpos can't be found, return a fake record which start from cpos
1054  *    and end at a small value between cpos+len and start of the next record.
1055  *    This fake record has r_refcount = 0.
1056  */
1057 static int ocfs2_get_refcount_rec(struct ocfs2_caching_info *ci,
1058                                   struct buffer_head *ref_root_bh,
1059                                   u64 cpos, unsigned int len,
1060                                   struct ocfs2_refcount_rec *ret_rec,
1061                                   int *index,
1062                                   struct buffer_head **ret_bh)
1063 {
1064         int ret = 0, i, found;
1065         u32 low_cpos, uninitialized_var(cpos_end);
1066         struct ocfs2_extent_list *el;
1067         struct ocfs2_extent_rec *rec = NULL;
1068         struct ocfs2_extent_block *eb = NULL;
1069         struct buffer_head *eb_bh = NULL, *ref_leaf_bh = NULL;
1070         struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
1071         struct ocfs2_refcount_block *rb =
1072                         (struct ocfs2_refcount_block *)ref_root_bh->b_data;
1073
1074         if (!(le32_to_cpu(rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL)) {
1075                 ocfs2_find_refcount_rec_in_rl(ci, ref_root_bh, cpos, len,
1076                                               ret_rec, index);
1077                 *ret_bh = ref_root_bh;
1078                 get_bh(ref_root_bh);
1079                 return 0;
1080         }
1081
1082         el = &rb->rf_list;
1083         low_cpos = cpos & OCFS2_32BIT_POS_MASK;
1084
1085         if (el->l_tree_depth) {
1086                 ret = ocfs2_find_leaf(ci, el, low_cpos, &eb_bh);
1087                 if (ret) {
1088                         mlog_errno(ret);
1089                         goto out;
1090                 }
1091
1092                 eb = (struct ocfs2_extent_block *) eb_bh->b_data;
1093                 el = &eb->h_list;
1094
1095                 if (el->l_tree_depth) {
1096                         ocfs2_error(sb,
1097                         "refcount tree %llu has non zero tree "
1098                         "depth in leaf btree tree block %llu\n",
1099                         (unsigned long long)ocfs2_metadata_cache_owner(ci),
1100                         (unsigned long long)eb_bh->b_blocknr);
1101                         ret = -EROFS;
1102                         goto out;
1103                 }
1104         }
1105
1106         found = 0;
1107         for (i = le16_to_cpu(el->l_next_free_rec) - 1; i >= 0; i--) {
1108                 rec = &el->l_recs[i];
1109
1110                 if (le32_to_cpu(rec->e_cpos) <= low_cpos) {
1111                         found = 1;
1112                         break;
1113                 }
1114         }
1115
1116         if (found) {
1117                 ret = ocfs2_get_refcount_cpos_end(ci, ref_root_bh,
1118                                                   eb, el, i, &cpos_end);
1119                 if (ret) {
1120                         mlog_errno(ret);
1121                         goto out;
1122                 }
1123
1124                 if (cpos_end < low_cpos + len)
1125                         len = cpos_end - low_cpos;
1126         }
1127
1128         ret = ocfs2_read_refcount_block(ci, le64_to_cpu(rec->e_blkno),
1129                                         &ref_leaf_bh);
1130         if (ret) {
1131                 mlog_errno(ret);
1132                 goto out;
1133         }
1134
1135         ocfs2_find_refcount_rec_in_rl(ci, ref_leaf_bh, cpos, len,
1136                                       ret_rec, index);
1137         *ret_bh = ref_leaf_bh;
1138 out:
1139         brelse(eb_bh);
1140         return ret;
1141 }
1142
1143 enum ocfs2_ref_rec_contig {
1144         REF_CONTIG_NONE = 0,
1145         REF_CONTIG_LEFT,
1146         REF_CONTIG_RIGHT,
1147         REF_CONTIG_LEFTRIGHT,
1148 };
1149
1150 static enum ocfs2_ref_rec_contig
1151         ocfs2_refcount_rec_adjacent(struct ocfs2_refcount_block *rb,
1152                                     int index)
1153 {
1154         if ((rb->rf_records.rl_recs[index].r_refcount ==
1155             rb->rf_records.rl_recs[index + 1].r_refcount) &&
1156             (le64_to_cpu(rb->rf_records.rl_recs[index].r_cpos) +
1157             le32_to_cpu(rb->rf_records.rl_recs[index].r_clusters) ==
1158             le64_to_cpu(rb->rf_records.rl_recs[index + 1].r_cpos)))
1159                 return REF_CONTIG_RIGHT;
1160
1161         return REF_CONTIG_NONE;
1162 }
1163
1164 static enum ocfs2_ref_rec_contig
1165         ocfs2_refcount_rec_contig(struct ocfs2_refcount_block *rb,
1166                                   int index)
1167 {
1168         enum ocfs2_ref_rec_contig ret = REF_CONTIG_NONE;
1169
1170         if (index < le16_to_cpu(rb->rf_records.rl_used) - 1)
1171                 ret = ocfs2_refcount_rec_adjacent(rb, index);
1172
1173         if (index > 0) {
1174                 enum ocfs2_ref_rec_contig tmp;
1175
1176                 tmp = ocfs2_refcount_rec_adjacent(rb, index - 1);
1177
1178                 if (tmp == REF_CONTIG_RIGHT) {
1179                         if (ret == REF_CONTIG_RIGHT)
1180                                 ret = REF_CONTIG_LEFTRIGHT;
1181                         else
1182                                 ret = REF_CONTIG_LEFT;
1183                 }
1184         }
1185
1186         return ret;
1187 }
1188
1189 static void ocfs2_rotate_refcount_rec_left(struct ocfs2_refcount_block *rb,
1190                                            int index)
1191 {
1192         BUG_ON(rb->rf_records.rl_recs[index].r_refcount !=
1193                rb->rf_records.rl_recs[index+1].r_refcount);
1194
1195         le32_add_cpu(&rb->rf_records.rl_recs[index].r_clusters,
1196                      le32_to_cpu(rb->rf_records.rl_recs[index+1].r_clusters));
1197
1198         if (index < le16_to_cpu(rb->rf_records.rl_used) - 2)
1199                 memmove(&rb->rf_records.rl_recs[index + 1],
1200                         &rb->rf_records.rl_recs[index + 2],
1201                         sizeof(struct ocfs2_refcount_rec) *
1202                         (le16_to_cpu(rb->rf_records.rl_used) - index - 2));
1203
1204         memset(&rb->rf_records.rl_recs[le16_to_cpu(rb->rf_records.rl_used) - 1],
1205                0, sizeof(struct ocfs2_refcount_rec));
1206         le16_add_cpu(&rb->rf_records.rl_used, -1);
1207 }
1208
1209 /*
1210  * Merge the refcount rec if we are contiguous with the adjacent recs.
1211  */
1212 static void ocfs2_refcount_rec_merge(struct ocfs2_refcount_block *rb,
1213                                      int index)
1214 {
1215         enum ocfs2_ref_rec_contig contig =
1216                                 ocfs2_refcount_rec_contig(rb, index);
1217
1218         if (contig == REF_CONTIG_NONE)
1219                 return;
1220
1221         if (contig == REF_CONTIG_LEFT || contig == REF_CONTIG_LEFTRIGHT) {
1222                 BUG_ON(index == 0);
1223                 index--;
1224         }
1225
1226         ocfs2_rotate_refcount_rec_left(rb, index);
1227
1228         if (contig == REF_CONTIG_LEFTRIGHT)
1229                 ocfs2_rotate_refcount_rec_left(rb, index);
1230 }
1231
1232 /*
1233  * Change the refcount indexed by "index" in ref_bh.
1234  * If refcount reaches 0, remove it.
1235  */
1236 static int ocfs2_change_refcount_rec(handle_t *handle,
1237                                      struct ocfs2_caching_info *ci,
1238                                      struct buffer_head *ref_leaf_bh,
1239                                      int index, int merge, int change)
1240 {
1241         int ret;
1242         struct ocfs2_refcount_block *rb =
1243                         (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
1244         struct ocfs2_refcount_list *rl = &rb->rf_records;
1245         struct ocfs2_refcount_rec *rec = &rl->rl_recs[index];
1246
1247         ret = ocfs2_journal_access_rb(handle, ci, ref_leaf_bh,
1248                                       OCFS2_JOURNAL_ACCESS_WRITE);
1249         if (ret) {
1250                 mlog_errno(ret);
1251                 goto out;
1252         }
1253
1254         mlog(0, "change index %d, old count %u, change %d\n", index,
1255              le32_to_cpu(rec->r_refcount), change);
1256         le32_add_cpu(&rec->r_refcount, change);
1257
1258         if (!rec->r_refcount) {
1259                 if (index != le16_to_cpu(rl->rl_used) - 1) {
1260                         memmove(rec, rec + 1,
1261                                 (le16_to_cpu(rl->rl_used) - index - 1) *
1262                                 sizeof(struct ocfs2_refcount_rec));
1263                         memset(&rl->rl_recs[le16_to_cpu(rl->rl_used) - 1],
1264                                0, sizeof(struct ocfs2_refcount_rec));
1265                 }
1266
1267                 le16_add_cpu(&rl->rl_used, -1);
1268         } else if (merge)
1269                 ocfs2_refcount_rec_merge(rb, index);
1270
1271         ret = ocfs2_journal_dirty(handle, ref_leaf_bh);
1272         if (ret)
1273                 mlog_errno(ret);
1274 out:
1275         return ret;
1276 }
1277
1278 static int ocfs2_expand_inline_ref_root(handle_t *handle,
1279                                         struct ocfs2_caching_info *ci,
1280                                         struct buffer_head *ref_root_bh,
1281                                         struct buffer_head **ref_leaf_bh,
1282                                         struct ocfs2_alloc_context *meta_ac)
1283 {
1284         int ret;
1285         u16 suballoc_bit_start;
1286         u32 num_got;
1287         u64 blkno;
1288         struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
1289         struct buffer_head *new_bh = NULL;
1290         struct ocfs2_refcount_block *new_rb;
1291         struct ocfs2_refcount_block *root_rb =
1292                         (struct ocfs2_refcount_block *)ref_root_bh->b_data;
1293
1294         ret = ocfs2_journal_access_rb(handle, ci, ref_root_bh,
1295                                       OCFS2_JOURNAL_ACCESS_WRITE);
1296         if (ret) {
1297                 mlog_errno(ret);
1298                 goto out;
1299         }
1300
1301         ret = ocfs2_claim_metadata(OCFS2_SB(sb), handle, meta_ac, 1,
1302                                    &suballoc_bit_start, &num_got,
1303                                    &blkno);
1304         if (ret) {
1305                 mlog_errno(ret);
1306                 goto out;
1307         }
1308
1309         new_bh = sb_getblk(sb, blkno);
1310         if (new_bh == NULL) {
1311                 ret = -EIO;
1312                 mlog_errno(ret);
1313                 goto out;
1314         }
1315         ocfs2_set_new_buffer_uptodate(ci, new_bh);
1316
1317         ret = ocfs2_journal_access_rb(handle, ci, new_bh,
1318                                       OCFS2_JOURNAL_ACCESS_CREATE);
1319         if (ret) {
1320                 mlog_errno(ret);
1321                 goto out;
1322         }
1323
1324         /*
1325          * Initialize ocfs2_refcount_block.
1326          * It should contain the same information as the old root.
1327          * so just memcpy it and change the corresponding field.
1328          */
1329         memcpy(new_bh->b_data, ref_root_bh->b_data, sb->s_blocksize);
1330
1331         new_rb = (struct ocfs2_refcount_block *)new_bh->b_data;
1332         new_rb->rf_suballoc_slot = cpu_to_le16(meta_ac->ac_alloc_slot);
1333         new_rb->rf_suballoc_bit = cpu_to_le16(suballoc_bit_start);
1334         new_rb->rf_blkno = cpu_to_le64(blkno);
1335         new_rb->rf_cpos = cpu_to_le32(0);
1336         new_rb->rf_parent = cpu_to_le64(ref_root_bh->b_blocknr);
1337         new_rb->rf_flags = cpu_to_le32(OCFS2_REFCOUNT_LEAF_FL);
1338         ocfs2_journal_dirty(handle, new_bh);
1339
1340         /* Now change the root. */
1341         memset(&root_rb->rf_list, 0, sb->s_blocksize -
1342                offsetof(struct ocfs2_refcount_block, rf_list));
1343         root_rb->rf_list.l_count = cpu_to_le16(ocfs2_extent_recs_per_rb(sb));
1344         root_rb->rf_clusters = cpu_to_le32(1);
1345         root_rb->rf_list.l_next_free_rec = cpu_to_le16(1);
1346         root_rb->rf_list.l_recs[0].e_blkno = cpu_to_le64(blkno);
1347         root_rb->rf_list.l_recs[0].e_leaf_clusters = cpu_to_le16(1);
1348         root_rb->rf_flags = cpu_to_le32(OCFS2_REFCOUNT_TREE_FL);
1349
1350         ocfs2_journal_dirty(handle, ref_root_bh);
1351
1352         mlog(0, "new leaf block %llu, used %u\n", (unsigned long long)blkno,
1353              le16_to_cpu(new_rb->rf_records.rl_used));
1354
1355         *ref_leaf_bh = new_bh;
1356         new_bh = NULL;
1357 out:
1358         brelse(new_bh);
1359         return ret;
1360 }
1361
1362 static int ocfs2_refcount_rec_no_intersect(struct ocfs2_refcount_rec *prev,
1363                                            struct ocfs2_refcount_rec *next)
1364 {
1365         if (ocfs2_get_ref_rec_low_cpos(prev) + le32_to_cpu(prev->r_clusters) <=
1366                 ocfs2_get_ref_rec_low_cpos(next))
1367                 return 1;
1368
1369         return 0;
1370 }
1371
1372 static int cmp_refcount_rec_by_low_cpos(const void *a, const void *b)
1373 {
1374         const struct ocfs2_refcount_rec *l = a, *r = b;
1375         u32 l_cpos = ocfs2_get_ref_rec_low_cpos(l);
1376         u32 r_cpos = ocfs2_get_ref_rec_low_cpos(r);
1377
1378         if (l_cpos > r_cpos)
1379                 return 1;
1380         if (l_cpos < r_cpos)
1381                 return -1;
1382         return 0;
1383 }
1384
1385 static int cmp_refcount_rec_by_cpos(const void *a, const void *b)
1386 {
1387         const struct ocfs2_refcount_rec *l = a, *r = b;
1388         u64 l_cpos = le64_to_cpu(l->r_cpos);
1389         u64 r_cpos = le64_to_cpu(r->r_cpos);
1390
1391         if (l_cpos > r_cpos)
1392                 return 1;
1393         if (l_cpos < r_cpos)
1394                 return -1;
1395         return 0;
1396 }
1397
1398 static void swap_refcount_rec(void *a, void *b, int size)
1399 {
1400         struct ocfs2_refcount_rec *l = a, *r = b, tmp;
1401
1402         tmp = *(struct ocfs2_refcount_rec *)l;
1403         *(struct ocfs2_refcount_rec *)l =
1404                         *(struct ocfs2_refcount_rec *)r;
1405         *(struct ocfs2_refcount_rec *)r = tmp;
1406 }
1407
1408 /*
1409  * The refcount cpos are ordered by their 64bit cpos,
1410  * But we will use the low 32 bit to be the e_cpos in the b-tree.
1411  * So we need to make sure that this pos isn't intersected with others.
1412  *
1413  * Note: The refcount block is already sorted by their low 32 bit cpos,
1414  *       So just try the middle pos first, and we will exit when we find
1415  *       the good position.
1416  */
1417 static int ocfs2_find_refcount_split_pos(struct ocfs2_refcount_list *rl,
1418                                          u32 *split_pos, int *split_index)
1419 {
1420         int num_used = le16_to_cpu(rl->rl_used);
1421         int delta, middle = num_used / 2;
1422
1423         for (delta = 0; delta < middle; delta++) {
1424                 /* Let's check delta earlier than middle */
1425                 if (ocfs2_refcount_rec_no_intersect(
1426                                         &rl->rl_recs[middle - delta - 1],
1427                                         &rl->rl_recs[middle - delta])) {
1428                         *split_index = middle - delta;
1429                         break;
1430                 }
1431
1432                 /* For even counts, don't walk off the end */
1433                 if ((middle + delta + 1) == num_used)
1434                         continue;
1435
1436                 /* Now try delta past middle */
1437                 if (ocfs2_refcount_rec_no_intersect(
1438                                         &rl->rl_recs[middle + delta],
1439                                         &rl->rl_recs[middle + delta + 1])) {
1440                         *split_index = middle + delta + 1;
1441                         break;
1442                 }
1443         }
1444
1445         if (delta >= middle)
1446                 return -ENOSPC;
1447
1448         *split_pos = ocfs2_get_ref_rec_low_cpos(&rl->rl_recs[*split_index]);
1449         return 0;
1450 }
1451
1452 static int ocfs2_divide_leaf_refcount_block(struct buffer_head *ref_leaf_bh,
1453                                             struct buffer_head *new_bh,
1454                                             u32 *split_cpos)
1455 {
1456         int split_index = 0, num_moved, ret;
1457         u32 cpos = 0;
1458         struct ocfs2_refcount_block *rb =
1459                         (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
1460         struct ocfs2_refcount_list *rl = &rb->rf_records;
1461         struct ocfs2_refcount_block *new_rb =
1462                         (struct ocfs2_refcount_block *)new_bh->b_data;
1463         struct ocfs2_refcount_list *new_rl = &new_rb->rf_records;
1464
1465         mlog(0, "split old leaf refcount block %llu, count = %u, used = %u\n",
1466              (unsigned long long)ref_leaf_bh->b_blocknr,
1467              le32_to_cpu(rl->rl_count), le32_to_cpu(rl->rl_used));
1468
1469         /*
1470          * XXX: Improvement later.
1471          * If we know all the high 32 bit cpos is the same, no need to sort.
1472          *
1473          * In order to make the whole process safe, we do:
1474          * 1. sort the entries by their low 32 bit cpos first so that we can
1475          *    find the split cpos easily.
1476          * 2. call ocfs2_insert_extent to insert the new refcount block.
1477          * 3. move the refcount rec to the new block.
1478          * 4. sort the entries by their 64 bit cpos.
1479          * 5. dirty the new_rb and rb.
1480          */
1481         sort(&rl->rl_recs, le16_to_cpu(rl->rl_used),
1482              sizeof(struct ocfs2_refcount_rec),
1483              cmp_refcount_rec_by_low_cpos, swap_refcount_rec);
1484
1485         ret = ocfs2_find_refcount_split_pos(rl, &cpos, &split_index);
1486         if (ret) {
1487                 mlog_errno(ret);
1488                 return ret;
1489         }
1490
1491         new_rb->rf_cpos = cpu_to_le32(cpos);
1492
1493         /* move refcount records starting from split_index to the new block. */
1494         num_moved = le16_to_cpu(rl->rl_used) - split_index;
1495         memcpy(new_rl->rl_recs, &rl->rl_recs[split_index],
1496                num_moved * sizeof(struct ocfs2_refcount_rec));
1497
1498         /*ok, remove the entries we just moved over to the other block. */
1499         memset(&rl->rl_recs[split_index], 0,
1500                num_moved * sizeof(struct ocfs2_refcount_rec));
1501
1502         /* change old and new rl_used accordingly. */
1503         le16_add_cpu(&rl->rl_used, -num_moved);
1504         new_rl->rl_used = cpu_to_le16(num_moved);
1505
1506         sort(&rl->rl_recs, le16_to_cpu(rl->rl_used),
1507              sizeof(struct ocfs2_refcount_rec),
1508              cmp_refcount_rec_by_cpos, swap_refcount_rec);
1509
1510         sort(&new_rl->rl_recs, le16_to_cpu(new_rl->rl_used),
1511              sizeof(struct ocfs2_refcount_rec),
1512              cmp_refcount_rec_by_cpos, swap_refcount_rec);
1513
1514         *split_cpos = cpos;
1515         return 0;
1516 }
1517
1518 static int ocfs2_new_leaf_refcount_block(handle_t *handle,
1519                                          struct ocfs2_caching_info *ci,
1520                                          struct buffer_head *ref_root_bh,
1521                                          struct buffer_head *ref_leaf_bh,
1522                                          struct ocfs2_alloc_context *meta_ac)
1523 {
1524         int ret;
1525         u16 suballoc_bit_start;
1526         u32 num_got, new_cpos;
1527         u64 blkno;
1528         struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
1529         struct ocfs2_refcount_block *root_rb =
1530                         (struct ocfs2_refcount_block *)ref_root_bh->b_data;
1531         struct buffer_head *new_bh = NULL;
1532         struct ocfs2_refcount_block *new_rb;
1533         struct ocfs2_extent_tree ref_et;
1534
1535         BUG_ON(!(le32_to_cpu(root_rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL));
1536
1537         ret = ocfs2_journal_access_rb(handle, ci, ref_root_bh,
1538                                       OCFS2_JOURNAL_ACCESS_WRITE);
1539         if (ret) {
1540                 mlog_errno(ret);
1541                 goto out;
1542         }
1543
1544         ret = ocfs2_journal_access_rb(handle, ci, ref_leaf_bh,
1545                                       OCFS2_JOURNAL_ACCESS_WRITE);
1546         if (ret) {
1547                 mlog_errno(ret);
1548                 goto out;
1549         }
1550
1551         ret = ocfs2_claim_metadata(OCFS2_SB(sb), handle, meta_ac, 1,
1552                                    &suballoc_bit_start, &num_got,
1553                                    &blkno);
1554         if (ret) {
1555                 mlog_errno(ret);
1556                 goto out;
1557         }
1558
1559         new_bh = sb_getblk(sb, blkno);
1560         if (new_bh == NULL) {
1561                 ret = -EIO;
1562                 mlog_errno(ret);
1563                 goto out;
1564         }
1565         ocfs2_set_new_buffer_uptodate(ci, new_bh);
1566
1567         ret = ocfs2_journal_access_rb(handle, ci, new_bh,
1568                                       OCFS2_JOURNAL_ACCESS_CREATE);
1569         if (ret) {
1570                 mlog_errno(ret);
1571                 goto out;
1572         }
1573
1574         /* Initialize ocfs2_refcount_block. */
1575         new_rb = (struct ocfs2_refcount_block *)new_bh->b_data;
1576         memset(new_rb, 0, sb->s_blocksize);
1577         strcpy((void *)new_rb, OCFS2_REFCOUNT_BLOCK_SIGNATURE);
1578         new_rb->rf_suballoc_slot = cpu_to_le16(meta_ac->ac_alloc_slot);
1579         new_rb->rf_suballoc_bit = cpu_to_le16(suballoc_bit_start);
1580         new_rb->rf_fs_generation = cpu_to_le32(OCFS2_SB(sb)->fs_generation);
1581         new_rb->rf_blkno = cpu_to_le64(blkno);
1582         new_rb->rf_parent = cpu_to_le64(ref_root_bh->b_blocknr);
1583         new_rb->rf_flags = cpu_to_le32(OCFS2_REFCOUNT_LEAF_FL);
1584         new_rb->rf_records.rl_count =
1585                                 cpu_to_le16(ocfs2_refcount_recs_per_rb(sb));
1586         new_rb->rf_generation = root_rb->rf_generation;
1587
1588         ret = ocfs2_divide_leaf_refcount_block(ref_leaf_bh, new_bh, &new_cpos);
1589         if (ret) {
1590                 mlog_errno(ret);
1591                 goto out;
1592         }
1593
1594         ocfs2_journal_dirty(handle, ref_leaf_bh);
1595         ocfs2_journal_dirty(handle, new_bh);
1596
1597         ocfs2_init_refcount_extent_tree(&ref_et, ci, ref_root_bh);
1598
1599         mlog(0, "insert new leaf block %llu at %u\n",
1600              (unsigned long long)new_bh->b_blocknr, new_cpos);
1601
1602         /* Insert the new leaf block with the specific offset cpos. */
1603         ret = ocfs2_insert_extent(handle, &ref_et, new_cpos, new_bh->b_blocknr,
1604                                   1, 0, meta_ac);
1605         if (ret)
1606                 mlog_errno(ret);
1607
1608 out:
1609         brelse(new_bh);
1610         return ret;
1611 }
1612
1613 static int ocfs2_expand_refcount_tree(handle_t *handle,
1614                                       struct ocfs2_caching_info *ci,
1615                                       struct buffer_head *ref_root_bh,
1616                                       struct buffer_head *ref_leaf_bh,
1617                                       struct ocfs2_alloc_context *meta_ac)
1618 {
1619         int ret;
1620         struct buffer_head *expand_bh = NULL;
1621
1622         if (ref_root_bh == ref_leaf_bh) {
1623                 /*
1624                  * the old root bh hasn't been expanded to a b-tree,
1625                  * so expand it first.
1626                  */
1627                 ret = ocfs2_expand_inline_ref_root(handle, ci, ref_root_bh,
1628                                                    &expand_bh, meta_ac);
1629                 if (ret) {
1630                         mlog_errno(ret);
1631                         goto out;
1632                 }
1633         } else {
1634                 expand_bh = ref_leaf_bh;
1635                 get_bh(expand_bh);
1636         }
1637
1638
1639         /* Now add a new refcount block into the tree.*/
1640         ret = ocfs2_new_leaf_refcount_block(handle, ci, ref_root_bh,
1641                                             expand_bh, meta_ac);
1642         if (ret)
1643                 mlog_errno(ret);
1644 out:
1645         brelse(expand_bh);
1646         return ret;
1647 }
1648
1649 /*
1650  * Adjust the extent rec in b-tree representing ref_leaf_bh.
1651  *
1652  * Only called when we have inserted a new refcount rec at index 0
1653  * which means ocfs2_extent_rec.e_cpos may need some change.
1654  */
1655 static int ocfs2_adjust_refcount_rec(handle_t *handle,
1656                                      struct ocfs2_caching_info *ci,
1657                                      struct buffer_head *ref_root_bh,
1658                                      struct buffer_head *ref_leaf_bh,
1659                                      struct ocfs2_refcount_rec *rec)
1660 {
1661         int ret = 0, i;
1662         u32 new_cpos, old_cpos;
1663         struct ocfs2_path *path = NULL;
1664         struct ocfs2_extent_tree et;
1665         struct ocfs2_refcount_block *rb =
1666                 (struct ocfs2_refcount_block *)ref_root_bh->b_data;
1667         struct ocfs2_extent_list *el;
1668
1669         if (!(le32_to_cpu(rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL))
1670                 goto out;
1671
1672         rb = (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
1673         old_cpos = le32_to_cpu(rb->rf_cpos);
1674         new_cpos = le64_to_cpu(rec->r_cpos) & OCFS2_32BIT_POS_MASK;
1675         if (old_cpos <= new_cpos)
1676                 goto out;
1677
1678         ocfs2_init_refcount_extent_tree(&et, ci, ref_root_bh);
1679
1680         path = ocfs2_new_path_from_et(&et);
1681         if (!path) {
1682                 ret = -ENOMEM;
1683                 mlog_errno(ret);
1684                 goto out;
1685         }
1686
1687         ret = ocfs2_find_path(ci, path, old_cpos);
1688         if (ret) {
1689                 mlog_errno(ret);
1690                 goto out;
1691         }
1692
1693         /*
1694          * 2 more credits, one for the leaf refcount block, one for
1695          * the extent block contains the extent rec.
1696          */
1697         ret = ocfs2_extend_trans(handle, handle->h_buffer_credits + 2);
1698         if (ret < 0) {
1699                 mlog_errno(ret);
1700                 goto out;
1701         }
1702
1703         ret = ocfs2_journal_access_rb(handle, ci, ref_leaf_bh,
1704                                       OCFS2_JOURNAL_ACCESS_WRITE);
1705         if (ret < 0) {
1706                 mlog_errno(ret);
1707                 goto out;
1708         }
1709
1710         ret = ocfs2_journal_access_eb(handle, ci, path_leaf_bh(path),
1711                                       OCFS2_JOURNAL_ACCESS_WRITE);
1712         if (ret < 0) {
1713                 mlog_errno(ret);
1714                 goto out;
1715         }
1716
1717         /* change the leaf extent block first. */
1718         el = path_leaf_el(path);
1719
1720         for (i = 0; i < le16_to_cpu(el->l_next_free_rec); i++)
1721                 if (le32_to_cpu(el->l_recs[i].e_cpos) == old_cpos)
1722                         break;
1723
1724         BUG_ON(i == le16_to_cpu(el->l_next_free_rec));
1725
1726         el->l_recs[i].e_cpos = cpu_to_le32(new_cpos);
1727
1728         /* change the r_cpos in the leaf block. */
1729         rb->rf_cpos = cpu_to_le32(new_cpos);
1730
1731         ocfs2_journal_dirty(handle, path_leaf_bh(path));
1732         ocfs2_journal_dirty(handle, ref_leaf_bh);
1733
1734 out:
1735         ocfs2_free_path(path);
1736         return ret;
1737 }
1738
1739 static int ocfs2_insert_refcount_rec(handle_t *handle,
1740                                      struct ocfs2_caching_info *ci,
1741                                      struct buffer_head *ref_root_bh,
1742                                      struct buffer_head *ref_leaf_bh,
1743                                      struct ocfs2_refcount_rec *rec,
1744                                      int index, int merge,
1745                                      struct ocfs2_alloc_context *meta_ac)
1746 {
1747         int ret;
1748         struct ocfs2_refcount_block *rb =
1749                         (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
1750         struct ocfs2_refcount_list *rf_list = &rb->rf_records;
1751         struct buffer_head *new_bh = NULL;
1752
1753         BUG_ON(le32_to_cpu(rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL);
1754
1755         if (rf_list->rl_used == rf_list->rl_count) {
1756                 u64 cpos = le64_to_cpu(rec->r_cpos);
1757                 u32 len = le32_to_cpu(rec->r_clusters);
1758
1759                 ret = ocfs2_expand_refcount_tree(handle, ci, ref_root_bh,
1760                                                  ref_leaf_bh, meta_ac);
1761                 if (ret) {
1762                         mlog_errno(ret);
1763                         goto out;
1764                 }
1765
1766                 ret = ocfs2_get_refcount_rec(ci, ref_root_bh,
1767                                              cpos, len, NULL, &index,
1768                                              &new_bh);
1769                 if (ret) {
1770                         mlog_errno(ret);
1771                         goto out;
1772                 }
1773
1774                 ref_leaf_bh = new_bh;
1775                 rb = (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
1776                 rf_list = &rb->rf_records;
1777         }
1778
1779         ret = ocfs2_journal_access_rb(handle, ci, ref_leaf_bh,
1780                                       OCFS2_JOURNAL_ACCESS_WRITE);
1781         if (ret) {
1782                 mlog_errno(ret);
1783                 goto out;
1784         }
1785
1786         if (index < le16_to_cpu(rf_list->rl_used))
1787                 memmove(&rf_list->rl_recs[index + 1],
1788                         &rf_list->rl_recs[index],
1789                         (le16_to_cpu(rf_list->rl_used) - index) *
1790                          sizeof(struct ocfs2_refcount_rec));
1791
1792         mlog(0, "insert refcount record start %llu, len %u, count %u "
1793              "to leaf block %llu at index %d\n",
1794              (unsigned long long)le64_to_cpu(rec->r_cpos),
1795              le32_to_cpu(rec->r_clusters), le32_to_cpu(rec->r_refcount),
1796              (unsigned long long)ref_leaf_bh->b_blocknr, index);
1797
1798         rf_list->rl_recs[index] = *rec;
1799
1800         le16_add_cpu(&rf_list->rl_used, 1);
1801
1802         if (merge)
1803                 ocfs2_refcount_rec_merge(rb, index);
1804
1805         ret = ocfs2_journal_dirty(handle, ref_leaf_bh);
1806         if (ret) {
1807                 mlog_errno(ret);
1808                 goto out;
1809         }
1810
1811         if (index == 0) {
1812                 ret = ocfs2_adjust_refcount_rec(handle, ci,
1813                                                 ref_root_bh,
1814                                                 ref_leaf_bh, rec);
1815                 if (ret)
1816                         mlog_errno(ret);
1817         }
1818 out:
1819         brelse(new_bh);
1820         return ret;
1821 }
1822
1823 /*
1824  * Split the refcount_rec indexed by "index" in ref_leaf_bh.
1825  * This is much simple than our b-tree code.
1826  * split_rec is the new refcount rec we want to insert.
1827  * If split_rec->r_refcount > 0, we are changing the refcount(in case we
1828  * increase refcount or decrease a refcount to non-zero).
1829  * If split_rec->r_refcount == 0, we are punching a hole in current refcount
1830  * rec( in case we decrease a refcount to zero).
1831  */
1832 static int ocfs2_split_refcount_rec(handle_t *handle,
1833                                     struct ocfs2_caching_info *ci,
1834                                     struct buffer_head *ref_root_bh,
1835                                     struct buffer_head *ref_leaf_bh,
1836                                     struct ocfs2_refcount_rec *split_rec,
1837                                     int index, int merge,
1838                                     struct ocfs2_alloc_context *meta_ac,
1839                                     struct ocfs2_cached_dealloc_ctxt *dealloc)
1840 {
1841         int ret, recs_need;
1842         u32 len;
1843         struct ocfs2_refcount_block *rb =
1844                         (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
1845         struct ocfs2_refcount_list *rf_list = &rb->rf_records;
1846         struct ocfs2_refcount_rec *orig_rec = &rf_list->rl_recs[index];
1847         struct ocfs2_refcount_rec *tail_rec = NULL;
1848         struct buffer_head *new_bh = NULL;
1849
1850         BUG_ON(le32_to_cpu(rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL);
1851
1852         mlog(0, "original r_pos %llu, cluster %u, split %llu, cluster %u\n",
1853              le64_to_cpu(orig_rec->r_cpos), le32_to_cpu(orig_rec->r_clusters),
1854              le64_to_cpu(split_rec->r_cpos),
1855              le32_to_cpu(split_rec->r_clusters));
1856
1857         /*
1858          * If we just need to split the header or tail clusters,
1859          * no more recs are needed, just split is OK.
1860          * Otherwise we at least need one new recs.
1861          */
1862         if (!split_rec->r_refcount &&
1863             (split_rec->r_cpos == orig_rec->r_cpos ||
1864              le64_to_cpu(split_rec->r_cpos) +
1865              le32_to_cpu(split_rec->r_clusters) ==
1866              le64_to_cpu(orig_rec->r_cpos) + le32_to_cpu(orig_rec->r_clusters)))
1867                 recs_need = 0;
1868         else
1869                 recs_need = 1;
1870
1871         /*
1872          * We need one more rec if we split in the middle and the new rec have
1873          * some refcount in it.
1874          */
1875         if (split_rec->r_refcount &&
1876             (split_rec->r_cpos != orig_rec->r_cpos &&
1877              le64_to_cpu(split_rec->r_cpos) +
1878              le32_to_cpu(split_rec->r_clusters) !=
1879              le64_to_cpu(orig_rec->r_cpos) + le32_to_cpu(orig_rec->r_clusters)))
1880                 recs_need++;
1881
1882         /* If the leaf block don't have enough record, expand it. */
1883         if (le16_to_cpu(rf_list->rl_used) + recs_need >
1884                                          le16_to_cpu(rf_list->rl_count)) {
1885                 struct ocfs2_refcount_rec tmp_rec;
1886                 u64 cpos = le64_to_cpu(orig_rec->r_cpos);
1887                 len = le32_to_cpu(orig_rec->r_clusters);
1888                 ret = ocfs2_expand_refcount_tree(handle, ci, ref_root_bh,
1889                                                  ref_leaf_bh, meta_ac);
1890                 if (ret) {
1891                         mlog_errno(ret);
1892                         goto out;
1893                 }
1894
1895                 /*
1896                  * We have to re-get it since now cpos may be moved to
1897                  * another leaf block.
1898                  */
1899                 ret = ocfs2_get_refcount_rec(ci, ref_root_bh,
1900                                              cpos, len, &tmp_rec, &index,
1901                                              &new_bh);
1902                 if (ret) {
1903                         mlog_errno(ret);
1904                         goto out;
1905                 }
1906
1907                 ref_leaf_bh = new_bh;
1908                 rb = (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
1909                 rf_list = &rb->rf_records;
1910                 orig_rec = &rf_list->rl_recs[index];
1911         }
1912
1913         ret = ocfs2_journal_access_rb(handle, ci, ref_leaf_bh,
1914                                       OCFS2_JOURNAL_ACCESS_WRITE);
1915         if (ret) {
1916                 mlog_errno(ret);
1917                 goto out;
1918         }
1919
1920         /*
1921          * We have calculated out how many new records we need and store
1922          * in recs_need, so spare enough space first by moving the records
1923          * after "index" to the end.
1924          */
1925         if (index != le16_to_cpu(rf_list->rl_used) - 1)
1926                 memmove(&rf_list->rl_recs[index + 1 + recs_need],
1927                         &rf_list->rl_recs[index + 1],
1928                         (le16_to_cpu(rf_list->rl_used) - index - 1) *
1929                          sizeof(struct ocfs2_refcount_rec));
1930
1931         len = (le64_to_cpu(orig_rec->r_cpos) +
1932               le32_to_cpu(orig_rec->r_clusters)) -
1933               (le64_to_cpu(split_rec->r_cpos) +
1934               le32_to_cpu(split_rec->r_clusters));
1935
1936         /*
1937          * If we have "len", the we will split in the tail and move it
1938          * to the end of the space we have just spared.
1939          */
1940         if (len) {
1941                 tail_rec = &rf_list->rl_recs[index + recs_need];
1942
1943                 memcpy(tail_rec, orig_rec, sizeof(struct ocfs2_refcount_rec));
1944                 le64_add_cpu(&tail_rec->r_cpos,
1945                              le32_to_cpu(tail_rec->r_clusters) - len);
1946                 tail_rec->r_clusters = cpu_to_le32(len);
1947         }
1948
1949         /*
1950          * If the split pos isn't the same as the original one, we need to
1951          * split in the head.
1952          *
1953          * Note: We have the chance that split_rec.r_refcount = 0,
1954          * recs_need = 0 and len > 0, which means we just cut the head from
1955          * the orig_rec and in that case we have done some modification in
1956          * orig_rec above, so the check for r_cpos is faked.
1957          */
1958         if (split_rec->r_cpos != orig_rec->r_cpos && tail_rec != orig_rec) {
1959                 len = le64_to_cpu(split_rec->r_cpos) -
1960                       le64_to_cpu(orig_rec->r_cpos);
1961                 orig_rec->r_clusters = cpu_to_le32(len);
1962                 index++;
1963         }
1964
1965         le16_add_cpu(&rf_list->rl_used, recs_need);
1966
1967         if (split_rec->r_refcount) {
1968                 rf_list->rl_recs[index] = *split_rec;
1969                 mlog(0, "insert refcount record start %llu, len %u, count %u "
1970                      "to leaf block %llu at index %d\n",
1971                      (unsigned long long)le64_to_cpu(split_rec->r_cpos),
1972                      le32_to_cpu(split_rec->r_clusters),
1973                      le32_to_cpu(split_rec->r_refcount),
1974                      (unsigned long long)ref_leaf_bh->b_blocknr, index);
1975
1976                 if (merge)
1977                         ocfs2_refcount_rec_merge(rb, index);
1978         }
1979
1980         ret = ocfs2_journal_dirty(handle, ref_leaf_bh);
1981         if (ret)
1982                 mlog_errno(ret);
1983
1984 out:
1985         brelse(new_bh);
1986         return ret;
1987 }
1988
1989 static int __ocfs2_increase_refcount(handle_t *handle,
1990                                      struct ocfs2_caching_info *ci,
1991                                      struct buffer_head *ref_root_bh,
1992                                      u64 cpos, u32 len, int merge,
1993                                      struct ocfs2_alloc_context *meta_ac,
1994                                      struct ocfs2_cached_dealloc_ctxt *dealloc)
1995 {
1996         int ret = 0, index;
1997         struct buffer_head *ref_leaf_bh = NULL;
1998         struct ocfs2_refcount_rec rec;
1999         unsigned int set_len = 0;
2000
2001         mlog(0, "Tree owner %llu, add refcount start %llu, len %u\n",
2002              (unsigned long long)ocfs2_metadata_cache_owner(ci),
2003              (unsigned long long)cpos, len);
2004
2005         while (len) {
2006                 ret = ocfs2_get_refcount_rec(ci, ref_root_bh,
2007                                              cpos, len, &rec, &index,
2008                                              &ref_leaf_bh);
2009                 if (ret) {
2010                         mlog_errno(ret);
2011                         goto out;
2012                 }
2013
2014                 set_len = le32_to_cpu(rec.r_clusters);
2015
2016                 /*
2017                  * Here we may meet with 3 situations:
2018                  *
2019                  * 1. If we find an already existing record, and the length
2020                  *    is the same, cool, we just need to increase the r_refcount
2021                  *    and it is OK.
2022                  * 2. If we find a hole, just insert it with r_refcount = 1.
2023                  * 3. If we are in the middle of one extent record, split
2024                  *    it.
2025                  */
2026                 if (rec.r_refcount && le64_to_cpu(rec.r_cpos) == cpos &&
2027                     set_len <= len) {
2028                         mlog(0, "increase refcount rec, start %llu, len %u, "
2029                              "count %u\n", (unsigned long long)cpos, set_len,
2030                              le32_to_cpu(rec.r_refcount));
2031                         ret = ocfs2_change_refcount_rec(handle, ci,
2032                                                         ref_leaf_bh, index,
2033                                                         merge, 1);
2034                         if (ret) {
2035                                 mlog_errno(ret);
2036                                 goto out;
2037                         }
2038                 } else if (!rec.r_refcount) {
2039                         rec.r_refcount = cpu_to_le32(1);
2040
2041                         mlog(0, "insert refcount rec, start %llu, len %u\n",
2042                              (unsigned long long)le64_to_cpu(rec.r_cpos),
2043                              set_len);
2044                         ret = ocfs2_insert_refcount_rec(handle, ci, ref_root_bh,
2045                                                         ref_leaf_bh,
2046                                                         &rec, index,
2047                                                         merge, meta_ac);
2048                         if (ret) {
2049                                 mlog_errno(ret);
2050                                 goto out;
2051                         }
2052                 } else  {
2053                         set_len = min((u64)(cpos + len),
2054                                       le64_to_cpu(rec.r_cpos) + set_len) - cpos;
2055                         rec.r_cpos = cpu_to_le64(cpos);
2056                         rec.r_clusters = cpu_to_le32(set_len);
2057                         le32_add_cpu(&rec.r_refcount, 1);
2058
2059                         mlog(0, "split refcount rec, start %llu, "
2060                              "len %u, count %u\n",
2061                              (unsigned long long)le64_to_cpu(rec.r_cpos),
2062                              set_len, le32_to_cpu(rec.r_refcount));
2063                         ret = ocfs2_split_refcount_rec(handle, ci,
2064                                                        ref_root_bh, ref_leaf_bh,
2065                                                        &rec, index, merge,
2066                                                        meta_ac, dealloc);
2067                         if (ret) {
2068                                 mlog_errno(ret);
2069                                 goto out;
2070                         }
2071                 }
2072
2073                 cpos += set_len;
2074                 len -= set_len;
2075                 brelse(ref_leaf_bh);
2076                 ref_leaf_bh = NULL;
2077         }
2078
2079 out:
2080         brelse(ref_leaf_bh);
2081         return ret;
2082 }
2083
2084 static int ocfs2_remove_refcount_extent(handle_t *handle,
2085                                 struct ocfs2_caching_info *ci,
2086                                 struct buffer_head *ref_root_bh,
2087                                 struct buffer_head *ref_leaf_bh,
2088                                 struct ocfs2_alloc_context *meta_ac,
2089                                 struct ocfs2_cached_dealloc_ctxt *dealloc)
2090 {
2091         int ret;
2092         struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
2093         struct ocfs2_refcount_block *rb =
2094                         (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
2095         struct ocfs2_extent_tree et;
2096
2097         BUG_ON(rb->rf_records.rl_used);
2098
2099         ocfs2_init_refcount_extent_tree(&et, ci, ref_root_bh);
2100         ret = ocfs2_remove_extent(handle, &et, le32_to_cpu(rb->rf_cpos),
2101                                   1, meta_ac, dealloc);
2102         if (ret) {
2103                 mlog_errno(ret);
2104                 goto out;
2105         }
2106
2107         ocfs2_remove_from_cache(ci, ref_leaf_bh);
2108
2109         /*
2110          * add the freed block to the dealloc so that it will be freed
2111          * when we run dealloc.
2112          */
2113         ret = ocfs2_cache_block_dealloc(dealloc, EXTENT_ALLOC_SYSTEM_INODE,
2114                                         le16_to_cpu(rb->rf_suballoc_slot),
2115                                         le64_to_cpu(rb->rf_blkno),
2116                                         le16_to_cpu(rb->rf_suballoc_bit));
2117         if (ret) {
2118                 mlog_errno(ret);
2119                 goto out;
2120         }
2121
2122         ret = ocfs2_journal_access_rb(handle, ci, ref_root_bh,
2123                                       OCFS2_JOURNAL_ACCESS_WRITE);
2124         if (ret) {
2125                 mlog_errno(ret);
2126                 goto out;
2127         }
2128
2129         rb = (struct ocfs2_refcount_block *)ref_root_bh->b_data;
2130
2131         le32_add_cpu(&rb->rf_clusters, -1);
2132
2133         /*
2134          * check whether we need to restore the root refcount block if
2135          * there is no leaf extent block at atll.
2136          */
2137         if (!rb->rf_list.l_next_free_rec) {
2138                 BUG_ON(rb->rf_clusters);
2139
2140                 mlog(0, "reset refcount tree root %llu to be a record block.\n",
2141                      (unsigned long long)ref_root_bh->b_blocknr);
2142
2143                 rb->rf_flags = 0;
2144                 rb->rf_parent = 0;
2145                 rb->rf_cpos = 0;
2146                 memset(&rb->rf_records, 0, sb->s_blocksize -
2147                        offsetof(struct ocfs2_refcount_block, rf_records));
2148                 rb->rf_records.rl_count =
2149                                 cpu_to_le16(ocfs2_refcount_recs_per_rb(sb));
2150         }
2151
2152         ocfs2_journal_dirty(handle, ref_root_bh);
2153
2154 out:
2155         return ret;
2156 }
2157
2158 int ocfs2_increase_refcount(handle_t *handle,
2159                             struct ocfs2_caching_info *ci,
2160                             struct buffer_head *ref_root_bh,
2161                             u64 cpos, u32 len,
2162                             struct ocfs2_alloc_context *meta_ac,
2163                             struct ocfs2_cached_dealloc_ctxt *dealloc)
2164 {
2165         return __ocfs2_increase_refcount(handle, ci, ref_root_bh,
2166                                          cpos, len, 1,
2167                                          meta_ac, dealloc);
2168 }
2169
2170 static int ocfs2_decrease_refcount_rec(handle_t *handle,
2171                                 struct ocfs2_caching_info *ci,
2172                                 struct buffer_head *ref_root_bh,
2173                                 struct buffer_head *ref_leaf_bh,
2174                                 int index, u64 cpos, unsigned int len,
2175                                 struct ocfs2_alloc_context *meta_ac,
2176                                 struct ocfs2_cached_dealloc_ctxt *dealloc)
2177 {
2178         int ret;
2179         struct ocfs2_refcount_block *rb =
2180                         (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
2181         struct ocfs2_refcount_rec *rec = &rb->rf_records.rl_recs[index];
2182
2183         BUG_ON(cpos < le64_to_cpu(rec->r_cpos));
2184         BUG_ON(cpos + len >
2185                le64_to_cpu(rec->r_cpos) + le32_to_cpu(rec->r_clusters));
2186
2187         if (cpos == le64_to_cpu(rec->r_cpos) &&
2188             len == le32_to_cpu(rec->r_clusters))
2189                 ret = ocfs2_change_refcount_rec(handle, ci,
2190                                                 ref_leaf_bh, index, 1, -1);
2191         else {
2192                 struct ocfs2_refcount_rec split = *rec;
2193                 split.r_cpos = cpu_to_le64(cpos);
2194                 split.r_clusters = cpu_to_le32(len);
2195
2196                 le32_add_cpu(&split.r_refcount, -1);
2197
2198                 mlog(0, "split refcount rec, start %llu, "
2199                      "len %u, count %u, original start %llu, len %u\n",
2200                      (unsigned long long)le64_to_cpu(split.r_cpos),
2201                      len, le32_to_cpu(split.r_refcount),
2202                      (unsigned long long)le64_to_cpu(rec->r_cpos),
2203                      le32_to_cpu(rec->r_clusters));
2204                 ret = ocfs2_split_refcount_rec(handle, ci,
2205                                                ref_root_bh, ref_leaf_bh,
2206                                                &split, index, 1,
2207                                                meta_ac, dealloc);
2208         }
2209
2210         if (ret) {
2211                 mlog_errno(ret);
2212                 goto out;
2213         }
2214
2215         /* Remove the leaf refcount block if it contains no refcount record. */
2216         if (!rb->rf_records.rl_used && ref_leaf_bh != ref_root_bh) {
2217                 ret = ocfs2_remove_refcount_extent(handle, ci, ref_root_bh,
2218                                                    ref_leaf_bh, meta_ac,
2219                                                    dealloc);
2220                 if (ret)
2221                         mlog_errno(ret);
2222         }
2223
2224 out:
2225         return ret;
2226 }
2227
2228 static int __ocfs2_decrease_refcount(handle_t *handle,
2229                                      struct ocfs2_caching_info *ci,
2230                                      struct buffer_head *ref_root_bh,
2231                                      u64 cpos, u32 len,
2232                                      struct ocfs2_alloc_context *meta_ac,
2233                                      struct ocfs2_cached_dealloc_ctxt *dealloc,
2234                                      int delete)
2235 {
2236         int ret = 0, index = 0;
2237         struct ocfs2_refcount_rec rec;
2238         unsigned int r_count = 0, r_len;
2239         struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
2240         struct buffer_head *ref_leaf_bh = NULL;
2241
2242         mlog(0, "Tree owner %llu, decrease refcount start %llu, "
2243              "len %u, delete %u\n",
2244              (unsigned long long)ocfs2_metadata_cache_owner(ci),
2245              (unsigned long long)cpos, len, delete);
2246
2247         while (len) {
2248                 ret = ocfs2_get_refcount_rec(ci, ref_root_bh,
2249                                              cpos, len, &rec, &index,
2250                                              &ref_leaf_bh);
2251                 if (ret) {
2252                         mlog_errno(ret);
2253                         goto out;
2254                 }
2255
2256                 r_count = le32_to_cpu(rec.r_refcount);
2257                 BUG_ON(r_count == 0);
2258                 if (!delete)
2259                         BUG_ON(r_count > 1);
2260
2261                 r_len = min((u64)(cpos + len), le64_to_cpu(rec.r_cpos) +
2262                               le32_to_cpu(rec.r_clusters)) - cpos;
2263
2264                 ret = ocfs2_decrease_refcount_rec(handle, ci, ref_root_bh,
2265                                                   ref_leaf_bh, index,
2266                                                   cpos, r_len,
2267                                                   meta_ac, dealloc);
2268                 if (ret) {
2269                         mlog_errno(ret);
2270                         goto out;
2271                 }
2272
2273                 if (le32_to_cpu(rec.r_refcount) == 1 && delete) {
2274                         ret = ocfs2_cache_cluster_dealloc(dealloc,
2275                                           ocfs2_clusters_to_blocks(sb, cpos),
2276                                                           r_len);
2277                         if (ret) {
2278                                 mlog_errno(ret);
2279                                 goto out;
2280                         }
2281                 }
2282
2283                 cpos += r_len;
2284                 len -= r_len;
2285                 brelse(ref_leaf_bh);
2286                 ref_leaf_bh = NULL;
2287         }
2288
2289 out:
2290         brelse(ref_leaf_bh);
2291         return ret;
2292 }
2293
2294 /* Caller must hold refcount tree lock. */
2295 int ocfs2_decrease_refcount(struct inode *inode,
2296                             handle_t *handle, u32 cpos, u32 len,
2297                             struct ocfs2_alloc_context *meta_ac,
2298                             struct ocfs2_cached_dealloc_ctxt *dealloc,
2299                             int delete)
2300 {
2301         int ret;
2302         u64 ref_blkno;
2303         struct ocfs2_inode_info *oi = OCFS2_I(inode);
2304         struct buffer_head *ref_root_bh = NULL;
2305         struct ocfs2_refcount_tree *tree;
2306
2307         BUG_ON(!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL));
2308
2309         ret = ocfs2_get_refcount_block(inode, &ref_blkno);
2310         if (ret) {
2311                 mlog_errno(ret);
2312                 goto out;
2313         }
2314
2315         ret = ocfs2_get_refcount_tree(OCFS2_SB(inode->i_sb), ref_blkno, &tree);
2316         if (ret) {
2317                 mlog_errno(ret);
2318                 goto out;
2319         }
2320
2321         ret = ocfs2_read_refcount_block(&tree->rf_ci, tree->rf_blkno,
2322                                         &ref_root_bh);
2323         if (ret) {
2324                 mlog_errno(ret);
2325                 goto out;
2326         }
2327
2328         ret = __ocfs2_decrease_refcount(handle, &tree->rf_ci, ref_root_bh,
2329                                         cpos, len, meta_ac, dealloc, delete);
2330         if (ret)
2331                 mlog_errno(ret);
2332 out:
2333         brelse(ref_root_bh);
2334         return ret;
2335 }
2336
2337 /*
2338  * Mark the already-existing extent at cpos as refcounted for len clusters.
2339  * This adds the refcount extent flag.
2340  *
2341  * If the existing extent is larger than the request, initiate a
2342  * split. An attempt will be made at merging with adjacent extents.
2343  *
2344  * The caller is responsible for passing down meta_ac if we'll need it.
2345  */
2346 static int ocfs2_mark_extent_refcounted(struct inode *inode,
2347                                 struct ocfs2_extent_tree *et,
2348                                 handle_t *handle, u32 cpos,
2349                                 u32 len, u32 phys,
2350                                 struct ocfs2_alloc_context *meta_ac,
2351                                 struct ocfs2_cached_dealloc_ctxt *dealloc)
2352 {
2353         int ret;
2354
2355         mlog(0, "Inode %lu refcount tree cpos %u, len %u, phys cluster %u\n",
2356              inode->i_ino, cpos, len, phys);
2357
2358         if (!ocfs2_refcount_tree(OCFS2_SB(inode->i_sb))) {
2359                 ocfs2_error(inode->i_sb, "Inode %lu want to use refcount "
2360                             "tree, but the feature bit is not set in the "
2361                             "super block.", inode->i_ino);
2362                 ret = -EROFS;
2363                 goto out;
2364         }
2365
2366         ret = ocfs2_change_extent_flag(handle, et, cpos,
2367                                        len, phys, meta_ac, dealloc,
2368                                        OCFS2_EXT_REFCOUNTED, 0);
2369         if (ret)
2370                 mlog_errno(ret);
2371
2372 out:
2373         return ret;
2374 }
2375
2376 /*
2377  * Given some contiguous physical clusters, calculate what we need
2378  * for modifying their refcount.
2379  */
2380 static int ocfs2_calc_refcount_meta_credits(struct super_block *sb,
2381                                             struct ocfs2_caching_info *ci,
2382                                             struct buffer_head *ref_root_bh,
2383                                             u64 start_cpos,
2384                                             u32 clusters,
2385                                             int *meta_add,
2386                                             int *credits)
2387 {
2388         int ret = 0, index, ref_blocks = 0, recs_add = 0;
2389         u64 cpos = start_cpos;
2390         struct ocfs2_refcount_block *rb;
2391         struct ocfs2_refcount_rec rec;
2392         struct buffer_head *ref_leaf_bh = NULL, *prev_bh = NULL;
2393         u32 len;
2394
2395         mlog(0, "start_cpos %llu, clusters %u\n",
2396              (unsigned long long)start_cpos, clusters);
2397         while (clusters) {
2398                 ret = ocfs2_get_refcount_rec(ci, ref_root_bh,
2399                                              cpos, clusters, &rec,
2400                                              &index, &ref_leaf_bh);
2401                 if (ret) {
2402                         mlog_errno(ret);
2403                         goto out;
2404                 }
2405
2406                 if (ref_leaf_bh != prev_bh) {
2407                         /*
2408                          * Now we encounter a new leaf block, so calculate
2409                          * whether we need to extend the old leaf.
2410                          */
2411                         if (prev_bh) {
2412                                 rb = (struct ocfs2_refcount_block *)
2413                                                         prev_bh->b_data;
2414
2415                                 if (le64_to_cpu(rb->rf_records.rl_used) +
2416                                     recs_add >
2417                                     le16_to_cpu(rb->rf_records.rl_count))
2418                                         ref_blocks++;
2419                         }
2420
2421                         recs_add = 0;
2422                         *credits += 1;
2423                         brelse(prev_bh);
2424                         prev_bh = ref_leaf_bh;
2425                         get_bh(prev_bh);
2426                 }
2427
2428                 rb = (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
2429
2430                 mlog(0, "recs_add %d,cpos %llu, clusters %u, rec->r_cpos %llu,"
2431                      "rec->r_clusters %u, rec->r_refcount %u, index %d\n",
2432                      recs_add, (unsigned long long)cpos, clusters,
2433                      (unsigned long long)le64_to_cpu(rec.r_cpos),
2434                      le32_to_cpu(rec.r_clusters),
2435                      le32_to_cpu(rec.r_refcount), index);
2436
2437                 len = min((u64)cpos + clusters, le64_to_cpu(rec.r_cpos) +
2438                           le32_to_cpu(rec.r_clusters)) - cpos;
2439                 /*
2440                  * If the refcount rec already exist, cool. We just need
2441                  * to check whether there is a split. Otherwise we just need
2442                  * to increase the refcount.
2443                  * If we will insert one, increases recs_add.
2444                  *
2445                  * We record all the records which will be inserted to the
2446                  * same refcount block, so that we can tell exactly whether
2447                  * we need a new refcount block or not.
2448                  */
2449                 if (rec.r_refcount) {
2450                         /* Check whether we need a split at the beginning. */
2451                         if (cpos == start_cpos &&
2452                             cpos != le64_to_cpu(rec.r_cpos))
2453                                 recs_add++;
2454
2455                         /* Check whether we need a split in the end. */
2456                         if (cpos + clusters < le64_to_cpu(rec.r_cpos) +
2457                             le32_to_cpu(rec.r_clusters))
2458                                 recs_add++;
2459                 } else
2460                         recs_add++;
2461
2462                 brelse(ref_leaf_bh);
2463                 ref_leaf_bh = NULL;
2464                 clusters -= len;
2465                 cpos += len;
2466         }
2467
2468         if (prev_bh) {
2469                 rb = (struct ocfs2_refcount_block *)prev_bh->b_data;
2470
2471                 if (le64_to_cpu(rb->rf_records.rl_used) + recs_add >
2472                     le16_to_cpu(rb->rf_records.rl_count))
2473                         ref_blocks++;
2474
2475                 *credits += 1;
2476         }
2477
2478         if (!ref_blocks)
2479                 goto out;
2480
2481         mlog(0, "we need ref_blocks %d\n", ref_blocks);
2482         *meta_add += ref_blocks;
2483         *credits += ref_blocks;
2484
2485         /*
2486          * So we may need ref_blocks to insert into the tree.
2487          * That also means we need to change the b-tree and add that number
2488          * of records since we never merge them.
2489          * We need one more block for expansion since the new created leaf
2490          * block is also full and needs split.
2491          */
2492         rb = (struct ocfs2_refcount_block *)ref_root_bh->b_data;
2493         if (le32_to_cpu(rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL) {
2494                 struct ocfs2_extent_tree et;
2495
2496                 ocfs2_init_refcount_extent_tree(&et, ci, ref_root_bh);
2497                 *meta_add += ocfs2_extend_meta_needed(et.et_root_el);
2498                 *credits += ocfs2_calc_extend_credits(sb,
2499                                                       et.et_root_el,
2500                                                       ref_blocks);
2501         } else {
2502                 *credits += OCFS2_EXPAND_REFCOUNT_TREE_CREDITS;
2503                 *meta_add += 1;
2504         }
2505
2506 out:
2507         brelse(ref_leaf_bh);
2508         brelse(prev_bh);
2509         return ret;
2510 }
2511
2512 /*
2513  * For refcount tree, we will decrease some contiguous clusters
2514  * refcount count, so just go through it to see how many blocks
2515  * we gonna touch and whether we need to create new blocks.
2516  *
2517  * Normally the refcount blocks store these refcount should be
2518  * contiguous also, so that we can get the number easily.
2519  * As for meta_ac, we will at most add split 2 refcount record and
2520  * 2 more refcount block, so just check it in a rough way.
2521  *
2522  * Caller must hold refcount tree lock.
2523  */
2524 int ocfs2_prepare_refcount_change_for_del(struct inode *inode,
2525                                           struct buffer_head *di_bh,
2526                                           u64 phys_blkno,
2527                                           u32 clusters,
2528                                           int *credits,
2529                                           struct ocfs2_alloc_context **meta_ac)
2530 {
2531         int ret, ref_blocks = 0;
2532         struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
2533         struct ocfs2_inode_info *oi = OCFS2_I(inode);
2534         struct buffer_head *ref_root_bh = NULL;
2535         struct ocfs2_refcount_tree *tree;
2536         u64 start_cpos = ocfs2_blocks_to_clusters(inode->i_sb, phys_blkno);
2537
2538         if (!ocfs2_refcount_tree(OCFS2_SB(inode->i_sb))) {
2539                 ocfs2_error(inode->i_sb, "Inode %lu want to use refcount "
2540                             "tree, but the feature bit is not set in the "
2541                             "super block.", inode->i_ino);
2542                 ret = -EROFS;
2543                 goto out;
2544         }
2545
2546         BUG_ON(!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL));
2547
2548         ret = ocfs2_get_refcount_tree(OCFS2_SB(inode->i_sb),
2549                                       le64_to_cpu(di->i_refcount_loc), &tree);
2550         if (ret) {
2551                 mlog_errno(ret);
2552                 goto out;
2553         }
2554
2555         ret = ocfs2_read_refcount_block(&tree->rf_ci,
2556                                         le64_to_cpu(di->i_refcount_loc),
2557                                         &ref_root_bh);
2558         if (ret) {
2559                 mlog_errno(ret);
2560                 goto out;
2561         }
2562
2563         ret = ocfs2_calc_refcount_meta_credits(inode->i_sb,
2564                                                &tree->rf_ci,
2565                                                ref_root_bh,
2566                                                start_cpos, clusters,
2567                                                &ref_blocks, credits);
2568         if (ret) {
2569                 mlog_errno(ret);
2570                 goto out;
2571         }
2572
2573         mlog(0, "reserve new metadata %d, credits = %d\n",
2574              ref_blocks, *credits);
2575
2576         if (ref_blocks) {
2577                 ret = ocfs2_reserve_new_metadata_blocks(OCFS2_SB(inode->i_sb),
2578                                                         ref_blocks, meta_ac);
2579                 if (ret)
2580                         mlog_errno(ret);
2581         }
2582
2583 out:
2584         brelse(ref_root_bh);
2585         return ret;
2586 }
2587
2588 #define MAX_CONTIG_BYTES        1048576
2589
2590 static inline unsigned int ocfs2_cow_contig_clusters(struct super_block *sb)
2591 {
2592         return ocfs2_clusters_for_bytes(sb, MAX_CONTIG_BYTES);
2593 }
2594
2595 static inline unsigned int ocfs2_cow_contig_mask(struct super_block *sb)
2596 {
2597         return ~(ocfs2_cow_contig_clusters(sb) - 1);
2598 }
2599
2600 /*
2601  * Given an extent that starts at 'start' and an I/O that starts at 'cpos',
2602  * find an offset (start + (n * contig_clusters)) that is closest to cpos
2603  * while still being less than or equal to it.
2604  *
2605  * The goal is to break the extent at a multiple of contig_clusters.
2606  */
2607 static inline unsigned int ocfs2_cow_align_start(struct super_block *sb,
2608                                                  unsigned int start,
2609                                                  unsigned int cpos)
2610 {
2611         BUG_ON(start > cpos);
2612
2613         return start + ((cpos - start) & ocfs2_cow_contig_mask(sb));
2614 }
2615
2616 /*
2617  * Given a cluster count of len, pad it out so that it is a multiple
2618  * of contig_clusters.
2619  */
2620 static inline unsigned int ocfs2_cow_align_length(struct super_block *sb,
2621                                                   unsigned int len)
2622 {
2623         unsigned int padded =
2624                 (len + (ocfs2_cow_contig_clusters(sb) - 1)) &
2625                 ocfs2_cow_contig_mask(sb);
2626
2627         /* Did we wrap? */
2628         if (padded < len)
2629                 padded = UINT_MAX;
2630
2631         return padded;
2632 }
2633
2634 /*
2635  * Calculate out the start and number of virtual clusters we need to to CoW.
2636  *
2637  * cpos is vitual start cluster position we want to do CoW in a
2638  * file and write_len is the cluster length.
2639  * max_cpos is the place where we want to stop CoW intentionally.
2640  *
2641  * Normal we will start CoW from the beginning of extent record cotaining cpos.
2642  * We try to break up extents on boundaries of MAX_CONTIG_BYTES so that we
2643  * get good I/O from the resulting extent tree.
2644  */
2645 static int ocfs2_refcount_cal_cow_clusters(struct inode *inode,
2646                                            struct ocfs2_extent_list *el,
2647                                            u32 cpos,
2648                                            u32 write_len,
2649                                            u32 max_cpos,
2650                                            u32 *cow_start,
2651                                            u32 *cow_len)
2652 {
2653         int ret = 0;
2654         int tree_height = le16_to_cpu(el->l_tree_depth), i;
2655         struct buffer_head *eb_bh = NULL;
2656         struct ocfs2_extent_block *eb = NULL;
2657         struct ocfs2_extent_rec *rec;
2658         unsigned int want_clusters, rec_end = 0;
2659         int contig_clusters = ocfs2_cow_contig_clusters(inode->i_sb);
2660         int leaf_clusters;
2661
2662         BUG_ON(cpos + write_len > max_cpos);
2663
2664         if (tree_height > 0) {
2665                 ret = ocfs2_find_leaf(INODE_CACHE(inode), el, cpos, &eb_bh);
2666                 if (ret) {
2667                         mlog_errno(ret);
2668                         goto out;
2669                 }
2670
2671                 eb = (struct ocfs2_extent_block *) eb_bh->b_data;
2672                 el = &eb->h_list;
2673
2674                 if (el->l_tree_depth) {
2675                         ocfs2_error(inode->i_sb,
2676                                     "Inode %lu has non zero tree depth in "
2677                                     "leaf block %llu\n", inode->i_ino,
2678                                     (unsigned long long)eb_bh->b_blocknr);
2679                         ret = -EROFS;
2680                         goto out;
2681                 }
2682         }
2683
2684         *cow_len = 0;
2685         for (i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
2686                 rec = &el->l_recs[i];
2687
2688                 if (ocfs2_is_empty_extent(rec)) {
2689                         mlog_bug_on_msg(i != 0, "Inode %lu has empty record in "
2690                                         "index %d\n", inode->i_ino, i);
2691                         continue;
2692                 }
2693
2694                 if (le32_to_cpu(rec->e_cpos) +
2695                     le16_to_cpu(rec->e_leaf_clusters) <= cpos)
2696                         continue;
2697
2698                 if (*cow_len == 0) {
2699                         /*
2700                          * We should find a refcounted record in the
2701                          * first pass.
2702                          */
2703                         BUG_ON(!(rec->e_flags & OCFS2_EXT_REFCOUNTED));
2704                         *cow_start = le32_to_cpu(rec->e_cpos);
2705                 }
2706
2707                 /*
2708                  * If we encounter a hole, a non-refcounted record or
2709                  * pass the max_cpos, stop the search.
2710                  */
2711                 if ((!(rec->e_flags & OCFS2_EXT_REFCOUNTED)) ||
2712                     (*cow_len && rec_end != le32_to_cpu(rec->e_cpos)) ||
2713                     (max_cpos <= le32_to_cpu(rec->e_cpos)))
2714                         break;
2715
2716                 leaf_clusters = le16_to_cpu(rec->e_leaf_clusters);
2717                 rec_end = le32_to_cpu(rec->e_cpos) + leaf_clusters;
2718                 if (rec_end > max_cpos) {
2719                         rec_end = max_cpos;
2720                         leaf_clusters = rec_end - le32_to_cpu(rec->e_cpos);
2721                 }
2722
2723                 /*
2724                  * How many clusters do we actually need from
2725                  * this extent?  First we see how many we actually
2726                  * need to complete the write.  If that's smaller
2727                  * than contig_clusters, we try for contig_clusters.
2728                  */
2729                 if (!*cow_len)
2730                         want_clusters = write_len;
2731                 else
2732                         want_clusters = (cpos + write_len) -
2733                                 (*cow_start + *cow_len);
2734                 if (want_clusters < contig_clusters)
2735                         want_clusters = contig_clusters;
2736
2737                 /*
2738                  * If the write does not cover the whole extent, we
2739                  * need to calculate how we're going to split the extent.
2740                  * We try to do it on contig_clusters boundaries.
2741                  *
2742                  * Any extent smaller than contig_clusters will be
2743                  * CoWed in its entirety.
2744                  */
2745                 if (leaf_clusters <= contig_clusters)
2746                         *cow_len += leaf_clusters;
2747                 else if (*cow_len || (*cow_start == cpos)) {
2748                         /*
2749                          * This extent needs to be CoW'd from its
2750                          * beginning, so all we have to do is compute
2751                          * how many clusters to grab.  We align
2752                          * want_clusters to the edge of contig_clusters
2753                          * to get better I/O.
2754                          */
2755                         want_clusters = ocfs2_cow_align_length(inode->i_sb,
2756                                                                want_clusters);
2757
2758                         if (leaf_clusters < want_clusters)
2759                                 *cow_len += leaf_clusters;
2760                         else
2761                                 *cow_len += want_clusters;
2762                 } else if ((*cow_start + contig_clusters) >=
2763                            (cpos + write_len)) {
2764                         /*
2765                          * Breaking off contig_clusters at the front
2766                          * of the extent will cover our write.  That's
2767                          * easy.
2768                          */
2769                         *cow_len = contig_clusters;
2770                 } else if ((rec_end - cpos) <= contig_clusters) {
2771                         /*
2772                          * Breaking off contig_clusters at the tail of
2773                          * this extent will cover cpos.
2774                          */
2775                         *cow_start = rec_end - contig_clusters;
2776                         *cow_len = contig_clusters;
2777                 } else if ((rec_end - cpos) <= want_clusters) {
2778                         /*
2779                          * While we can't fit the entire write in this
2780                          * extent, we know that the write goes from cpos
2781                          * to the end of the extent.  Break that off.
2782                          * We try to break it at some multiple of
2783                          * contig_clusters from the front of the extent.
2784                          * Failing that (ie, cpos is within
2785                          * contig_clusters of the front), we'll CoW the
2786                          * entire extent.
2787                          */
2788                         *cow_start = ocfs2_cow_align_start(inode->i_sb,
2789                                                            *cow_start, cpos);
2790                         *cow_len = rec_end - *cow_start;
2791                 } else {
2792                         /*
2793                          * Ok, the entire write lives in the middle of
2794                          * this extent.  Let's try to slice the extent up
2795                          * nicely.  Optimally, our CoW region starts at
2796                          * m*contig_clusters from the beginning of the
2797                          * extent and goes for n*contig_clusters,
2798                          * covering the entire write.
2799                          */
2800                         *cow_start = ocfs2_cow_align_start(inode->i_sb,
2801                                                            *cow_start, cpos);
2802
2803                         want_clusters = (cpos + write_len) - *cow_start;
2804                         want_clusters = ocfs2_cow_align_length(inode->i_sb,
2805                                                                want_clusters);
2806                         if (*cow_start + want_clusters <= rec_end)
2807                                 *cow_len = want_clusters;
2808                         else
2809                                 *cow_len = rec_end - *cow_start;
2810                 }
2811
2812                 /* Have we covered our entire write yet? */
2813                 if ((*cow_start + *cow_len) >= (cpos + write_len))
2814                         break;
2815
2816                 /*
2817                  * If we reach the end of the extent block and don't get enough
2818                  * clusters, continue with the next extent block if possible.
2819                  */
2820                 if (i + 1 == le16_to_cpu(el->l_next_free_rec) &&
2821                     eb && eb->h_next_leaf_blk) {
2822                         brelse(eb_bh);
2823                         eb_bh = NULL;
2824
2825                         ret = ocfs2_read_extent_block(INODE_CACHE(inode),
2826                                                le64_to_cpu(eb->h_next_leaf_blk),
2827                                                &eb_bh);
2828                         if (ret) {
2829                                 mlog_errno(ret);
2830                                 goto out;
2831                         }
2832
2833                         eb = (struct ocfs2_extent_block *) eb_bh->b_data;
2834                         el = &eb->h_list;
2835                         i = -1;
2836                 }
2837         }
2838
2839 out:
2840         brelse(eb_bh);
2841         return ret;
2842 }
2843
2844 /*
2845  * Prepare meta_ac, data_ac and calculate credits when we want to add some
2846  * num_clusters in data_tree "et" and change the refcount for the old
2847  * clusters(starting form p_cluster) in the refcount tree.
2848  *
2849  * Note:
2850  * 1. since we may split the old tree, so we at most will need num_clusters + 2
2851  *    more new leaf records.
2852  * 2. In some case, we may not need to reserve new clusters(e.g, reflink), so
2853  *    just give data_ac = NULL.
2854  */
2855 static int ocfs2_lock_refcount_allocators(struct super_block *sb,
2856                                         u32 p_cluster, u32 num_clusters,
2857                                         struct ocfs2_extent_tree *et,
2858                                         struct ocfs2_caching_info *ref_ci,
2859                                         struct buffer_head *ref_root_bh,
2860                                         struct ocfs2_alloc_context **meta_ac,
2861                                         struct ocfs2_alloc_context **data_ac,
2862                                         int *credits)
2863 {
2864         int ret = 0, meta_add = 0;
2865         int num_free_extents = ocfs2_num_free_extents(OCFS2_SB(sb), et);
2866
2867         if (num_free_extents < 0) {
2868                 ret = num_free_extents;
2869                 mlog_errno(ret);
2870                 goto out;
2871         }
2872
2873         if (num_free_extents < num_clusters + 2)
2874                 meta_add =
2875                         ocfs2_extend_meta_needed(et->et_root_el);
2876
2877         *credits += ocfs2_calc_extend_credits(sb, et->et_root_el,
2878                                               num_clusters + 2);
2879
2880         ret = ocfs2_calc_refcount_meta_credits(sb, ref_ci, ref_root_bh,
2881                                                p_cluster, num_clusters,
2882                                                &meta_add, credits);
2883         if (ret) {
2884                 mlog_errno(ret);
2885                 goto out;
2886         }
2887
2888         mlog(0, "reserve new metadata %d, clusters %u, credits = %d\n",
2889              meta_add, num_clusters, *credits);
2890         ret = ocfs2_reserve_new_metadata_blocks(OCFS2_SB(sb), meta_add,
2891                                                 meta_ac);
2892         if (ret) {
2893                 mlog_errno(ret);
2894                 goto out;
2895         }
2896
2897         if (data_ac) {
2898                 ret = ocfs2_reserve_clusters(OCFS2_SB(sb), num_clusters,
2899                                              data_ac);
2900                 if (ret)
2901                         mlog_errno(ret);
2902         }
2903
2904 out:
2905         if (ret) {
2906                 if (*meta_ac) {
2907                         ocfs2_free_alloc_context(*meta_ac);
2908                         *meta_ac = NULL;
2909                 }
2910         }
2911
2912         return ret;
2913 }
2914
2915 static int ocfs2_clear_cow_buffer(handle_t *handle, struct buffer_head *bh)
2916 {
2917         BUG_ON(buffer_dirty(bh));
2918
2919         clear_buffer_mapped(bh);
2920
2921         return 0;
2922 }
2923
2924 static int ocfs2_duplicate_clusters_by_page(handle_t *handle,
2925                                             struct ocfs2_cow_context *context,
2926                                             u32 cpos, u32 old_cluster,
2927                                             u32 new_cluster, u32 new_len)
2928 {
2929         int ret = 0, partial;
2930         struct ocfs2_caching_info *ci = context->data_et.et_ci;
2931         struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
2932         u64 new_block = ocfs2_clusters_to_blocks(sb, new_cluster);
2933         struct page *page;
2934         pgoff_t page_index;
2935         unsigned int from, to;
2936         loff_t offset, end, map_end;
2937         struct address_space *mapping = context->inode->i_mapping;
2938
2939         mlog(0, "old_cluster %u, new %u, len %u at offset %u\n", old_cluster,
2940              new_cluster, new_len, cpos);
2941
2942         offset = ((loff_t)cpos) << OCFS2_SB(sb)->s_clustersize_bits;
2943         end = offset + (new_len << OCFS2_SB(sb)->s_clustersize_bits);
2944
2945         while (offset < end) {
2946                 page_index = offset >> PAGE_CACHE_SHIFT;
2947                 map_end = ((loff_t)page_index + 1) << PAGE_CACHE_SHIFT;
2948                 if (map_end > end)
2949                         map_end = end;
2950
2951                 /* from, to is the offset within the page. */
2952                 from = offset & (PAGE_CACHE_SIZE - 1);
2953                 to = PAGE_CACHE_SIZE;
2954                 if (map_end & (PAGE_CACHE_SIZE - 1))
2955                         to = map_end & (PAGE_CACHE_SIZE - 1);
2956
2957                 page = grab_cache_page(mapping, page_index);
2958
2959                 /*
2960                  * In case PAGE_CACHE_SIZE <= CLUSTER_SIZE, This page
2961                  * can't be dirtied before we CoW it out.
2962                  */
2963                 if (PAGE_CACHE_SIZE <= OCFS2_SB(sb)->s_clustersize)
2964                         BUG_ON(PageDirty(page));
2965
2966                 if (!PageUptodate(page)) {
2967                         ret = block_read_full_page(page, ocfs2_get_block);
2968                         if (ret) {
2969                                 mlog_errno(ret);
2970                                 goto unlock;
2971                         }
2972                         lock_page(page);
2973                 }
2974
2975                 if (page_has_buffers(page)) {
2976                         ret = walk_page_buffers(handle, page_buffers(page),
2977                                                 from, to, &partial,
2978                                                 ocfs2_clear_cow_buffer);
2979                         if (ret) {
2980                                 mlog_errno(ret);
2981                                 goto unlock;
2982                         }
2983                 }
2984
2985                 ocfs2_map_and_dirty_page(context->inode,
2986                                          handle, from, to,
2987                                          page, 0, &new_block);
2988                 mark_page_accessed(page);
2989 unlock:
2990                 unlock_page(page);
2991                 page_cache_release(page);
2992                 page = NULL;
2993                 offset = map_end;
2994                 if (ret)
2995                         break;
2996         }
2997
2998         return ret;
2999 }
3000
3001 static int ocfs2_duplicate_clusters_by_jbd(handle_t *handle,
3002                                            struct ocfs2_cow_context *context,
3003                                            u32 cpos, u32 old_cluster,
3004                                            u32 new_cluster, u32 new_len)
3005 {
3006         int ret = 0;
3007         struct super_block *sb = context->inode->i_sb;
3008         struct ocfs2_caching_info *ci = context->data_et.et_ci;
3009         int i, blocks = ocfs2_clusters_to_blocks(sb, new_len);
3010         u64 old_block = ocfs2_clusters_to_blocks(sb, old_cluster);
3011         u64 new_block = ocfs2_clusters_to_blocks(sb, new_cluster);
3012         struct ocfs2_super *osb = OCFS2_SB(sb);
3013         struct buffer_head *old_bh = NULL;
3014         struct buffer_head *new_bh = NULL;
3015
3016         mlog(0, "old_cluster %u, new %u, len %u\n", old_cluster,
3017              new_cluster, new_len);
3018
3019         for (i = 0; i < blocks; i++, old_block++, new_block++) {
3020                 new_bh = sb_getblk(osb->sb, new_block);
3021                 if (new_bh == NULL) {
3022                         ret = -EIO;
3023                         mlog_errno(ret);
3024                         break;
3025                 }
3026
3027                 ocfs2_set_new_buffer_uptodate(ci, new_bh);
3028
3029                 ret = ocfs2_read_block(ci, old_block, &old_bh, NULL);
3030                 if (ret) {
3031                         mlog_errno(ret);
3032                         break;
3033                 }
3034
3035                 ret = ocfs2_journal_access(handle, ci, new_bh,
3036                                            OCFS2_JOURNAL_ACCESS_CREATE);
3037                 if (ret) {
3038                         mlog_errno(ret);
3039                         break;
3040                 }
3041
3042                 memcpy(new_bh->b_data, old_bh->b_data, sb->s_blocksize);
3043                 ret = ocfs2_journal_dirty(handle, new_bh);
3044                 if (ret) {
3045                         mlog_errno(ret);
3046                         break;
3047                 }
3048
3049                 brelse(new_bh);
3050                 brelse(old_bh);
3051                 new_bh = NULL;
3052                 old_bh = NULL;
3053         }
3054
3055         brelse(new_bh);
3056         brelse(old_bh);
3057         return ret;
3058 }
3059
3060 static int ocfs2_clear_ext_refcount(handle_t *handle,
3061                                     struct ocfs2_extent_tree *et,
3062                                     u32 cpos, u32 p_cluster, u32 len,
3063                                     unsigned int ext_flags,
3064                                     struct ocfs2_alloc_context *meta_ac,
3065                                     struct ocfs2_cached_dealloc_ctxt *dealloc)
3066 {
3067         int ret, index;
3068         struct ocfs2_extent_rec replace_rec;
3069         struct ocfs2_path *path = NULL;
3070         struct ocfs2_extent_list *el;
3071         struct super_block *sb = ocfs2_metadata_cache_get_super(et->et_ci);
3072         u64 ino = ocfs2_metadata_cache_owner(et->et_ci);
3073
3074         mlog(0, "inode %llu cpos %u, len %u, p_cluster %u, ext_flags %u\n",
3075              (unsigned long long)ino, cpos, len, p_cluster, ext_flags);
3076
3077         memset(&replace_rec, 0, sizeof(replace_rec));
3078         replace_rec.e_cpos = cpu_to_le32(cpos);
3079         replace_rec.e_leaf_clusters = cpu_to_le16(len);
3080         replace_rec.e_blkno = cpu_to_le64(ocfs2_clusters_to_blocks(sb,
3081                                                                    p_cluster));
3082         replace_rec.e_flags = ext_flags;
3083         replace_rec.e_flags &= ~OCFS2_EXT_REFCOUNTED;
3084
3085         path = ocfs2_new_path_from_et(et);
3086         if (!path) {
3087                 ret = -ENOMEM;
3088                 mlog_errno(ret);
3089                 goto out;
3090         }
3091
3092         ret = ocfs2_find_path(et->et_ci, path, cpos);
3093         if (ret) {
3094                 mlog_errno(ret);
3095                 goto out;
3096         }
3097
3098         el = path_leaf_el(path);
3099
3100         index = ocfs2_search_extent_list(el, cpos);
3101         if (index == -1 || index >= le16_to_cpu(el->l_next_free_rec)) {
3102                 ocfs2_error(sb,
3103                             "Inode %llu has an extent at cpos %u which can no "
3104                             "longer be found.\n",
3105                             (unsigned long long)ino, cpos);
3106                 ret = -EROFS;
3107                 goto out;
3108         }
3109
3110         ret = ocfs2_split_extent(handle, et, path, index,
3111                                  &replace_rec, meta_ac, dealloc);
3112         if (ret)
3113                 mlog_errno(ret);
3114
3115 out:
3116         ocfs2_free_path(path);
3117         return ret;
3118 }
3119
3120 static int ocfs2_replace_clusters(handle_t *handle,
3121                                   struct ocfs2_cow_context *context,
3122                                   u32 cpos, u32 old,
3123                                   u32 new, u32 len,
3124                                   unsigned int ext_flags)
3125 {
3126         int ret;
3127         struct ocfs2_caching_info *ci = context->data_et.et_ci;
3128         u64 ino = ocfs2_metadata_cache_owner(ci);
3129
3130         mlog(0, "inode %llu, cpos %u, old %u, new %u, len %u, ext_flags %u\n",
3131              (unsigned long long)ino, cpos, old, new, len, ext_flags);
3132
3133         /*If the old clusters is unwritten, no need to duplicate. */
3134         if (!(ext_flags & OCFS2_EXT_UNWRITTEN)) {
3135                 ret = context->cow_duplicate_clusters(handle, context, cpos,
3136                                                       old, new, len);
3137                 if (ret) {
3138                         mlog_errno(ret);
3139                         goto out;
3140                 }
3141         }
3142
3143         ret = ocfs2_clear_ext_refcount(handle, &context->data_et,
3144                                        cpos, new, len, ext_flags,
3145                                        context->meta_ac, &context->dealloc);
3146         if (ret)
3147                 mlog_errno(ret);
3148 out:
3149         return ret;
3150 }
3151
3152 static int ocfs2_cow_sync_writeback(struct super_block *sb,
3153                                     struct ocfs2_cow_context *context,
3154                                     u32 cpos, u32 num_clusters)
3155 {
3156         int ret = 0;
3157         loff_t offset, end, map_end;
3158         pgoff_t page_index;
3159         struct page *page;
3160
3161         if (ocfs2_should_order_data(context->inode))
3162                 return 0;
3163
3164         offset = ((loff_t)cpos) << OCFS2_SB(sb)->s_clustersize_bits;
3165         end = offset + (num_clusters << OCFS2_SB(sb)->s_clustersize_bits);
3166
3167         ret = filemap_fdatawrite_range(context->inode->i_mapping,
3168                                        offset, end - 1);
3169         if (ret < 0) {
3170                 mlog_errno(ret);
3171                 return ret;
3172         }
3173
3174         while (offset < end) {
3175                 page_index = offset >> PAGE_CACHE_SHIFT;
3176                 map_end = ((loff_t)page_index + 1) << PAGE_CACHE_SHIFT;
3177                 if (map_end > end)
3178                         map_end = end;
3179
3180                 page = grab_cache_page(context->inode->i_mapping, page_index);
3181                 BUG_ON(!page);
3182
3183                 wait_on_page_writeback(page);
3184                 if (PageError(page)) {
3185                         ret = -EIO;
3186                         mlog_errno(ret);
3187                 } else
3188                         mark_page_accessed(page);
3189
3190                 unlock_page(page);
3191                 page_cache_release(page);
3192                 page = NULL;
3193                 offset = map_end;
3194                 if (ret)
3195                         break;
3196         }
3197
3198         return ret;
3199 }
3200
3201 static int ocfs2_di_get_clusters(struct ocfs2_cow_context *context,
3202                                  u32 v_cluster, u32 *p_cluster,
3203                                  u32 *num_clusters,
3204                                  unsigned int *extent_flags)
3205 {
3206         return ocfs2_get_clusters(context->inode, v_cluster, p_cluster,
3207                                   num_clusters, extent_flags);
3208 }
3209
3210 static int ocfs2_make_clusters_writable(struct super_block *sb,
3211                                         struct ocfs2_cow_context *context,
3212                                         u32 cpos, u32 p_cluster,
3213                                         u32 num_clusters, unsigned int e_flags)
3214 {
3215         int ret, delete, index, credits =  0;
3216         u32 new_bit, new_len;
3217         unsigned int set_len;
3218         struct ocfs2_super *osb = OCFS2_SB(sb);
3219         handle_t *handle;
3220         struct buffer_head *ref_leaf_bh = NULL;
3221         struct ocfs2_caching_info *ref_ci = &context->ref_tree->rf_ci;
3222         struct ocfs2_refcount_rec rec;
3223
3224         mlog(0, "cpos %u, p_cluster %u, num_clusters %u, e_flags %u\n",
3225              cpos, p_cluster, num_clusters, e_flags);
3226
3227         ret = ocfs2_lock_refcount_allocators(sb, p_cluster, num_clusters,
3228                                              &context->data_et,
3229                                              ref_ci,
3230                                              context->ref_root_bh,
3231                                              &context->meta_ac,
3232                                              &context->data_ac, &credits);
3233         if (ret) {
3234                 mlog_errno(ret);
3235                 return ret;
3236         }
3237
3238         if (context->post_refcount)
3239                 credits += context->post_refcount->credits;
3240
3241         credits += context->extra_credits;
3242         handle = ocfs2_start_trans(osb, credits);
3243         if (IS_ERR(handle)) {
3244                 ret = PTR_ERR(handle);
3245                 mlog_errno(ret);
3246                 goto out;
3247         }
3248
3249         while (num_clusters) {
3250                 ret = ocfs2_get_refcount_rec(ref_ci, context->ref_root_bh,
3251                                              p_cluster, num_clusters,
3252                                              &rec, &index, &ref_leaf_bh);
3253                 if (ret) {
3254                         mlog_errno(ret);
3255                         goto out_commit;
3256                 }
3257
3258                 BUG_ON(!rec.r_refcount);
3259                 set_len = min((u64)p_cluster + num_clusters,
3260                               le64_to_cpu(rec.r_cpos) +
3261                               le32_to_cpu(rec.r_clusters)) - p_cluster;
3262
3263                 /*
3264                  * There are many different situation here.
3265                  * 1. If refcount == 1, remove the flag and don't COW.
3266                  * 2. If refcount > 1, allocate clusters.
3267                  *    Here we may not allocate r_len once at a time, so continue
3268                  *    until we reach num_clusters.
3269                  */
3270                 if (le32_to_cpu(rec.r_refcount) == 1) {
3271                         delete = 0;
3272                         ret = ocfs2_clear_ext_refcount(handle,
3273                                                        &context->data_et,
3274                                                        cpos, p_cluster,
3275                                                        set_len, e_flags,
3276                                                        context->meta_ac,
3277                                                        &context->dealloc);
3278                         if (ret) {
3279                                 mlog_errno(ret);
3280                                 goto out_commit;
3281                         }
3282                 } else {
3283                         delete = 1;
3284
3285                         ret = __ocfs2_claim_clusters(osb, handle,
3286                                                      context->data_ac,
3287                                                      1, set_len,
3288                                                      &new_bit, &new_len);
3289                         if (ret) {
3290                                 mlog_errno(ret);
3291                                 goto out_commit;
3292                         }
3293
3294                         ret = ocfs2_replace_clusters(handle, context,
3295                                                      cpos, p_cluster, new_bit,
3296                                                      new_len, e_flags);
3297                         if (ret) {
3298                                 mlog_errno(ret);
3299                                 goto out_commit;
3300                         }
3301                         set_len = new_len;
3302                 }
3303
3304                 ret = __ocfs2_decrease_refcount(handle, ref_ci,
3305                                                 context->ref_root_bh,
3306                                                 p_cluster, set_len,
3307                                                 context->meta_ac,
3308                                                 &context->dealloc, delete);
3309                 if (ret) {
3310                         mlog_errno(ret);
3311                         goto out_commit;
3312                 }
3313
3314                 cpos += set_len;
3315                 p_cluster += set_len;
3316                 num_clusters -= set_len;
3317                 brelse(ref_leaf_bh);
3318                 ref_leaf_bh = NULL;
3319         }
3320
3321         /* handle any post_cow action. */
3322         if (context->post_refcount && context->post_refcount->func) {
3323                 ret = context->post_refcount->func(context->inode, handle,
3324                                                 context->post_refcount->para);
3325                 if (ret) {
3326                         mlog_errno(ret);
3327                         goto out_commit;
3328                 }
3329         }
3330
3331         /*
3332          * Here we should write the new page out first if we are
3333          * in write-back mode.
3334          */
3335         if (context->get_clusters == ocfs2_di_get_clusters) {
3336                 ret = ocfs2_cow_sync_writeback(sb, context, cpos, num_clusters);
3337                 if (ret)
3338                         mlog_errno(ret);
3339         }
3340
3341 out_commit:
3342         ocfs2_commit_trans(osb, handle);
3343
3344 out:
3345         if (context->data_ac) {
3346                 ocfs2_free_alloc_context(context->data_ac);
3347                 context->data_ac = NULL;
3348         }
3349         if (context->meta_ac) {
3350                 ocfs2_free_alloc_context(context->meta_ac);
3351                 context->meta_ac = NULL;
3352         }
3353         brelse(ref_leaf_bh);
3354
3355         return ret;
3356 }
3357
3358 static int ocfs2_replace_cow(struct ocfs2_cow_context *context)
3359 {
3360         int ret = 0;
3361         struct inode *inode = context->inode;
3362         u32 cow_start = context->cow_start, cow_len = context->cow_len;
3363         u32 p_cluster, num_clusters;
3364         unsigned int ext_flags;
3365         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
3366
3367         if (!ocfs2_refcount_tree(OCFS2_SB(inode->i_sb))) {
3368                 ocfs2_error(inode->i_sb, "Inode %lu want to use refcount "
3369                             "tree, but the feature bit is not set in the "
3370                             "super block.", inode->i_ino);
3371                 return -EROFS;
3372         }
3373
3374         ocfs2_init_dealloc_ctxt(&context->dealloc);
3375
3376         while (cow_len) {
3377                 ret = context->get_clusters(context, cow_start, &p_cluster,
3378                                             &num_clusters, &ext_flags);
3379                 if (ret) {
3380                         mlog_errno(ret);
3381                         break;
3382                 }
3383
3384                 BUG_ON(!(ext_flags & OCFS2_EXT_REFCOUNTED));
3385
3386                 if (cow_len < num_clusters)
3387                         num_clusters = cow_len;
3388
3389                 ret = ocfs2_make_clusters_writable(inode->i_sb, context,
3390                                                    cow_start, p_cluster,
3391                                                    num_clusters, ext_flags);
3392                 if (ret) {
3393                         mlog_errno(ret);
3394                         break;
3395                 }
3396
3397                 cow_len -= num_clusters;
3398                 cow_start += num_clusters;
3399         }
3400
3401         if (ocfs2_dealloc_has_cluster(&context->dealloc)) {
3402                 ocfs2_schedule_truncate_log_flush(osb, 1);
3403                 ocfs2_run_deallocs(osb, &context->dealloc);
3404         }
3405
3406         return ret;
3407 }
3408
3409 /*
3410  * Starting at cpos, try to CoW write_len clusters.  Don't CoW
3411  * past max_cpos.  This will stop when it runs into a hole or an
3412  * unrefcounted extent.
3413  */
3414 static int ocfs2_refcount_cow_hunk(struct inode *inode,
3415                                    struct buffer_head *di_bh,
3416                                    u32 cpos, u32 write_len, u32 max_cpos)
3417 {
3418         int ret;
3419         u32 cow_start = 0, cow_len = 0;
3420         struct ocfs2_inode_info *oi = OCFS2_I(inode);
3421         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
3422         struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
3423         struct buffer_head *ref_root_bh = NULL;
3424         struct ocfs2_refcount_tree *ref_tree;
3425         struct ocfs2_cow_context *context = NULL;
3426
3427         BUG_ON(!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL));
3428
3429         ret = ocfs2_refcount_cal_cow_clusters(inode, &di->id2.i_list,
3430                                               cpos, write_len, max_cpos,
3431                                               &cow_start, &cow_len);
3432         if (ret) {
3433                 mlog_errno(ret);
3434                 goto out;
3435         }
3436
3437         mlog(0, "CoW inode %lu, cpos %u, write_len %u, cow_start %u, "
3438              "cow_len %u\n", inode->i_ino,
3439              cpos, write_len, cow_start, cow_len);
3440
3441         BUG_ON(cow_len == 0);
3442
3443         context = kzalloc(sizeof(struct ocfs2_cow_context), GFP_NOFS);
3444         if (!context) {
3445                 ret = -ENOMEM;
3446                 mlog_errno(ret);
3447                 goto out;
3448         }
3449
3450         ret = ocfs2_lock_refcount_tree(osb, le64_to_cpu(di->i_refcount_loc),
3451                                        1, &ref_tree, &ref_root_bh);
3452         if (ret) {
3453                 mlog_errno(ret);
3454                 goto out;
3455         }
3456
3457         context->inode = inode;
3458         context->cow_start = cow_start;
3459         context->cow_len = cow_len;
3460         context->ref_tree = ref_tree;
3461         context->ref_root_bh = ref_root_bh;
3462         context->cow_duplicate_clusters = ocfs2_duplicate_clusters_by_page;
3463         context->get_clusters = ocfs2_di_get_clusters;
3464
3465         ocfs2_init_dinode_extent_tree(&context->data_et,
3466                                       INODE_CACHE(inode), di_bh);
3467
3468         ret = ocfs2_replace_cow(context);
3469         if (ret)
3470                 mlog_errno(ret);
3471
3472         /*
3473          * truncate the extent map here since no matter whether we meet with
3474          * any error during the action, we shouldn't trust cached extent map
3475          * any more.
3476          */
3477         ocfs2_extent_map_trunc(inode, cow_start);
3478
3479         ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
3480         brelse(ref_root_bh);
3481 out:
3482         kfree(context);
3483         return ret;
3484 }
3485
3486 /*
3487  * CoW any and all clusters between cpos and cpos+write_len.
3488  * Don't CoW past max_cpos.  If this returns successfully, all
3489  * clusters between cpos and cpos+write_len are safe to modify.
3490  */
3491 int ocfs2_refcount_cow(struct inode *inode,
3492                        struct buffer_head *di_bh,
3493                        u32 cpos, u32 write_len, u32 max_cpos)
3494 {
3495         int ret = 0;
3496         u32 p_cluster, num_clusters;
3497         unsigned int ext_flags;
3498
3499         while (write_len) {
3500                 ret = ocfs2_get_clusters(inode, cpos, &p_cluster,
3501                                          &num_clusters, &ext_flags);
3502                 if (ret) {
3503                         mlog_errno(ret);
3504                         break;
3505                 }
3506
3507                 if (write_len < num_clusters)
3508                         num_clusters = write_len;
3509
3510                 if (ext_flags & OCFS2_EXT_REFCOUNTED) {
3511                         ret = ocfs2_refcount_cow_hunk(inode, di_bh, cpos,
3512                                                       num_clusters, max_cpos);
3513                         if (ret) {
3514                                 mlog_errno(ret);
3515                                 break;
3516                         }
3517                 }
3518
3519                 write_len -= num_clusters;
3520                 cpos += num_clusters;
3521         }
3522
3523         return ret;
3524 }
3525
3526 static int ocfs2_xattr_value_get_clusters(struct ocfs2_cow_context *context,
3527                                           u32 v_cluster, u32 *p_cluster,
3528                                           u32 *num_clusters,
3529                                           unsigned int *extent_flags)
3530 {
3531         struct inode *inode = context->inode;
3532         struct ocfs2_xattr_value_root *xv = context->cow_object;
3533
3534         return ocfs2_xattr_get_clusters(inode, v_cluster, p_cluster,
3535                                         num_clusters, &xv->xr_list,
3536                                         extent_flags);
3537 }
3538
3539 /*
3540  * Given a xattr value root, calculate the most meta/credits we need for
3541  * refcount tree change if we truncate it to 0.
3542  */
3543 int ocfs2_refcounted_xattr_delete_need(struct inode *inode,
3544                                        struct ocfs2_caching_info *ref_ci,
3545                                        struct buffer_head *ref_root_bh,
3546                                        struct ocfs2_xattr_value_root *xv,
3547                                        int *meta_add, int *credits)
3548 {
3549         int ret = 0, index, ref_blocks = 0;
3550         u32 p_cluster, num_clusters;
3551         u32 cpos = 0, clusters = le32_to_cpu(xv->xr_clusters);
3552         struct ocfs2_refcount_block *rb;
3553         struct ocfs2_refcount_rec rec;
3554         struct buffer_head *ref_leaf_bh = NULL;
3555
3556         while (cpos < clusters) {
3557                 ret = ocfs2_xattr_get_clusters(inode, cpos, &p_cluster,
3558                                                &num_clusters, &xv->xr_list,
3559                                                NULL);
3560                 if (ret) {
3561                         mlog_errno(ret);
3562                         goto out;
3563                 }
3564
3565                 cpos += num_clusters;
3566
3567                 while (num_clusters) {
3568                         ret = ocfs2_get_refcount_rec(ref_ci, ref_root_bh,
3569                                                      p_cluster, num_clusters,
3570                                                      &rec, &index,
3571                                                      &ref_leaf_bh);
3572                         if (ret) {
3573                                 mlog_errno(ret);
3574                                 goto out;
3575                         }
3576
3577                         BUG_ON(!rec.r_refcount);
3578
3579                         rb = (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
3580
3581                         /*
3582                          * We really don't know whether the other clusters is in
3583                          * this refcount block or not, so just take the worst
3584                          * case that all the clusters are in this block and each
3585                          * one will split a refcount rec, so totally we need
3586                          * clusters * 2 new refcount rec.
3587                          */
3588                         if (le64_to_cpu(rb->rf_records.rl_used) + clusters * 2 >
3589                             le16_to_cpu(rb->rf_records.rl_count))
3590                                 ref_blocks++;
3591
3592                         *credits += 1;
3593                         brelse(ref_leaf_bh);
3594                         ref_leaf_bh = NULL;
3595
3596                         if (num_clusters <= le32_to_cpu(rec.r_clusters))
3597                                 break;
3598                         else
3599                                 num_clusters -= le32_to_cpu(rec.r_clusters);
3600                         p_cluster += num_clusters;
3601                 }
3602         }
3603
3604         *meta_add += ref_blocks;
3605         if (!ref_blocks)
3606                 goto out;
3607
3608         rb = (struct ocfs2_refcount_block *)ref_root_bh->b_data;
3609         if (le32_to_cpu(rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL)
3610                 *credits += OCFS2_EXPAND_REFCOUNT_TREE_CREDITS;
3611         else {
3612                 struct ocfs2_extent_tree et;
3613
3614                 ocfs2_init_refcount_extent_tree(&et, ref_ci, ref_root_bh);
3615                 *credits += ocfs2_calc_extend_credits(inode->i_sb,
3616                                                       et.et_root_el,
3617                                                       ref_blocks);
3618         }
3619
3620 out:
3621         brelse(ref_leaf_bh);
3622         return ret;
3623 }
3624
3625 /*
3626  * Do CoW for xattr.
3627  */
3628 int ocfs2_refcount_cow_xattr(struct inode *inode,
3629                              struct ocfs2_dinode *di,
3630                              struct ocfs2_xattr_value_buf *vb,
3631                              struct ocfs2_refcount_tree *ref_tree,
3632                              struct buffer_head *ref_root_bh,
3633                              u32 cpos, u32 write_len,
3634                              struct ocfs2_post_refcount *post)
3635 {
3636         int ret;
3637         struct ocfs2_xattr_value_root *xv = vb->vb_xv;
3638         struct ocfs2_inode_info *oi = OCFS2_I(inode);
3639         struct ocfs2_cow_context *context = NULL;
3640         u32 cow_start, cow_len;
3641
3642         BUG_ON(!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL));
3643
3644         ret = ocfs2_refcount_cal_cow_clusters(inode, &xv->xr_list,
3645                                               cpos, write_len, UINT_MAX,
3646                                               &cow_start, &cow_len);
3647         if (ret) {
3648                 mlog_errno(ret);
3649                 goto out;
3650         }
3651
3652         BUG_ON(cow_len == 0);
3653
3654         context = kzalloc(sizeof(struct ocfs2_cow_context), GFP_NOFS);
3655         if (!context) {
3656                 ret = -ENOMEM;
3657                 mlog_errno(ret);
3658                 goto out;
3659         }
3660
3661         context->inode = inode;
3662         context->cow_start = cow_start;
3663         context->cow_len = cow_len;
3664         context->ref_tree = ref_tree;
3665         context->ref_root_bh = ref_root_bh;;
3666         context->cow_object = xv;
3667
3668         context->cow_duplicate_clusters = ocfs2_duplicate_clusters_by_jbd;
3669         /* We need the extra credits for duplicate_clusters by jbd. */
3670         context->extra_credits =
3671                 ocfs2_clusters_to_blocks(inode->i_sb, 1) * cow_len;
3672         context->get_clusters = ocfs2_xattr_value_get_clusters;
3673         context->post_refcount = post;
3674
3675         ocfs2_init_xattr_value_extent_tree(&context->data_et,
3676                                            INODE_CACHE(inode), vb);
3677
3678         ret = ocfs2_replace_cow(context);
3679         if (ret)
3680                 mlog_errno(ret);
3681
3682 out:
3683         kfree(context);
3684         return ret;
3685 }
3686
3687 /*
3688  * Insert a new extent into refcount tree and mark a extent rec
3689  * as refcounted in the dinode tree.
3690  */
3691 int ocfs2_add_refcount_flag(struct inode *inode,
3692                             struct ocfs2_extent_tree *data_et,
3693                             struct ocfs2_caching_info *ref_ci,
3694                             struct buffer_head *ref_root_bh,
3695                             u32 cpos, u32 p_cluster, u32 num_clusters,
3696                             struct ocfs2_cached_dealloc_ctxt *dealloc,
3697                             struct ocfs2_post_refcount *post)
3698 {
3699         int ret;
3700         handle_t *handle;
3701         int credits = 1, ref_blocks = 0;
3702         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
3703         struct ocfs2_alloc_context *meta_ac = NULL;
3704
3705         ret = ocfs2_calc_refcount_meta_credits(inode->i_sb,
3706                                                ref_ci, ref_root_bh,
3707                                                p_cluster, num_clusters,
3708                                                &ref_blocks, &credits);
3709         if (ret) {
3710                 mlog_errno(ret);
3711                 goto out;
3712         }
3713
3714         mlog(0, "reserve new metadata %d, credits = %d\n",
3715              ref_blocks, credits);
3716
3717         if (ref_blocks) {
3718                 ret = ocfs2_reserve_new_metadata_blocks(OCFS2_SB(inode->i_sb),
3719                                                         ref_blocks, &meta_ac);
3720                 if (ret) {
3721                         mlog_errno(ret);
3722                         goto out;
3723                 }
3724         }
3725
3726         if (post)
3727                 credits += post->credits;
3728
3729         handle = ocfs2_start_trans(osb, credits);
3730         if (IS_ERR(handle)) {
3731                 ret = PTR_ERR(handle);
3732                 mlog_errno(ret);
3733                 goto out;
3734         }
3735
3736         ret = ocfs2_mark_extent_refcounted(inode, data_et, handle,
3737                                            cpos, num_clusters, p_cluster,
3738                                            meta_ac, dealloc);
3739         if (ret) {
3740                 mlog_errno(ret);
3741                 goto out_commit;
3742         }
3743
3744         ret = __ocfs2_increase_refcount(handle, ref_ci, ref_root_bh,
3745                                         p_cluster, num_clusters, 0,
3746                                         meta_ac, dealloc);
3747         if (ret) {
3748                 mlog_errno(ret);
3749                 goto out_commit;
3750         }
3751
3752         if (post && post->func) {
3753                 ret = post->func(inode, handle, post->para);
3754                 if (ret)
3755                         mlog_errno(ret);
3756         }
3757
3758 out_commit:
3759         ocfs2_commit_trans(osb, handle);
3760 out:
3761         if (meta_ac)
3762                 ocfs2_free_alloc_context(meta_ac);
3763         return ret;
3764 }
3765
3766 static int ocfs2_change_ctime(struct inode *inode,
3767                               struct buffer_head *di_bh)
3768 {
3769         int ret;
3770         handle_t *handle;
3771         struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
3772
3773         handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb),
3774                                    OCFS2_INODE_UPDATE_CREDITS);
3775         if (IS_ERR(handle)) {
3776                 ret = PTR_ERR(handle);
3777                 mlog_errno(ret);
3778                 goto out;
3779         }
3780
3781         ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
3782                                       OCFS2_JOURNAL_ACCESS_WRITE);
3783         if (ret) {
3784                 mlog_errno(ret);
3785                 goto out_commit;
3786         }
3787
3788         inode->i_ctime = CURRENT_TIME;
3789         di->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
3790         di->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
3791
3792         ocfs2_journal_dirty(handle, di_bh);
3793
3794 out_commit:
3795         ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
3796 out:
3797         return ret;
3798 }
3799
3800 static int ocfs2_attach_refcount_tree(struct inode *inode,
3801                                       struct buffer_head *di_bh)
3802 {
3803         int ret, data_changed = 0;
3804         struct buffer_head *ref_root_bh = NULL;
3805         struct ocfs2_inode_info *oi = OCFS2_I(inode);
3806         struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
3807         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
3808         struct ocfs2_refcount_tree *ref_tree;
3809         unsigned int ext_flags;
3810         loff_t size;
3811         u32 cpos, num_clusters, clusters, p_cluster;
3812         struct ocfs2_cached_dealloc_ctxt dealloc;
3813         struct ocfs2_extent_tree di_et;
3814
3815         ocfs2_init_dealloc_ctxt(&dealloc);
3816
3817         if (!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL)) {
3818                 ret = ocfs2_create_refcount_tree(inode, di_bh);
3819                 if (ret) {
3820                         mlog_errno(ret);
3821                         goto out;
3822                 }
3823         }
3824
3825         BUG_ON(!di->i_refcount_loc);
3826         ret = ocfs2_lock_refcount_tree(osb,
3827                                        le64_to_cpu(di->i_refcount_loc), 1,
3828                                        &ref_tree, &ref_root_bh);
3829         if (ret) {
3830                 mlog_errno(ret);
3831                 goto out;
3832         }
3833
3834         if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
3835                 goto attach_xattr;
3836
3837         ocfs2_init_dinode_extent_tree(&di_et, INODE_CACHE(inode), di_bh);
3838
3839         size = i_size_read(inode);
3840         clusters = ocfs2_clusters_for_bytes(inode->i_sb, size);
3841
3842         cpos = 0;
3843         while (cpos < clusters) {
3844                 ret = ocfs2_get_clusters(inode, cpos, &p_cluster,
3845                                          &num_clusters, &ext_flags);
3846
3847                 if (p_cluster && !(ext_flags & OCFS2_EXT_REFCOUNTED)) {
3848                         ret = ocfs2_add_refcount_flag(inode, &di_et,
3849                                                       &ref_tree->rf_ci,
3850                                                       ref_root_bh, cpos,
3851                                                       p_cluster, num_clusters,
3852                                                       &dealloc, NULL);
3853                         if (ret) {
3854                                 mlog_errno(ret);
3855                                 goto unlock;
3856                         }
3857
3858                         data_changed = 1;
3859                 }
3860                 cpos += num_clusters;
3861         }
3862
3863 attach_xattr:
3864         if (oi->ip_dyn_features & OCFS2_HAS_XATTR_FL) {
3865                 ret = ocfs2_xattr_attach_refcount_tree(inode, di_bh,
3866                                                        &ref_tree->rf_ci,
3867                                                        ref_root_bh,
3868                                                        &dealloc);
3869                 if (ret) {
3870                         mlog_errno(ret);
3871                         goto unlock;
3872                 }
3873         }
3874
3875         if (data_changed) {
3876                 ret = ocfs2_change_ctime(inode, di_bh);
3877                 if (ret)
3878                         mlog_errno(ret);
3879         }
3880
3881 unlock:
3882         ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
3883         brelse(ref_root_bh);
3884
3885         if (!ret && ocfs2_dealloc_has_cluster(&dealloc)) {
3886                 ocfs2_schedule_truncate_log_flush(osb, 1);
3887                 ocfs2_run_deallocs(osb, &dealloc);
3888         }
3889 out:
3890         /*
3891          * Empty the extent map so that we may get the right extent
3892          * record from the disk.
3893          */
3894         ocfs2_extent_map_trunc(inode, 0);
3895
3896         return ret;
3897 }
3898
3899 static int ocfs2_add_refcounted_extent(struct inode *inode,
3900                                    struct ocfs2_extent_tree *et,
3901                                    struct ocfs2_caching_info *ref_ci,
3902                                    struct buffer_head *ref_root_bh,
3903                                    u32 cpos, u32 p_cluster, u32 num_clusters,
3904                                    unsigned int ext_flags,
3905                                    struct ocfs2_cached_dealloc_ctxt *dealloc)
3906 {
3907         int ret;
3908         handle_t *handle;
3909         int credits = 0;
3910         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
3911         struct ocfs2_alloc_context *meta_ac = NULL;
3912
3913         ret = ocfs2_lock_refcount_allocators(inode->i_sb,
3914                                              p_cluster, num_clusters,
3915                                              et, ref_ci,
3916                                              ref_root_bh, &meta_ac,
3917                                              NULL, &credits);
3918         if (ret) {
3919                 mlog_errno(ret);
3920                 goto out;
3921         }
3922
3923         handle = ocfs2_start_trans(osb, credits);
3924         if (IS_ERR(handle)) {
3925                 ret = PTR_ERR(handle);
3926                 mlog_errno(ret);
3927                 goto out;
3928         }
3929
3930         ret = ocfs2_insert_extent(handle, et, cpos,
3931                         ocfs2_clusters_to_blocks(inode->i_sb, p_cluster),
3932                         num_clusters, ext_flags, meta_ac);
3933         if (ret) {
3934                 mlog_errno(ret);
3935                 goto out_commit;
3936         }
3937
3938         ret = ocfs2_increase_refcount(handle, ref_ci, ref_root_bh,
3939                                       p_cluster, num_clusters,
3940                                       meta_ac, dealloc);
3941         if (ret)
3942                 mlog_errno(ret);
3943
3944 out_commit:
3945         ocfs2_commit_trans(osb, handle);
3946 out:
3947         if (meta_ac)
3948                 ocfs2_free_alloc_context(meta_ac);
3949         return ret;
3950 }
3951
3952 static int ocfs2_duplicate_inline_data(struct inode *s_inode,
3953                                        struct buffer_head *s_bh,
3954                                        struct inode *t_inode,
3955                                        struct buffer_head *t_bh)
3956 {
3957         int ret;
3958         handle_t *handle;
3959         struct ocfs2_super *osb = OCFS2_SB(s_inode->i_sb);
3960         struct ocfs2_dinode *s_di = (struct ocfs2_dinode *)s_bh->b_data;
3961         struct ocfs2_dinode *t_di = (struct ocfs2_dinode *)t_bh->b_data;
3962
3963         BUG_ON(!(OCFS2_I(s_inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL));
3964
3965         handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
3966         if (IS_ERR(handle)) {
3967                 ret = PTR_ERR(handle);
3968                 mlog_errno(ret);
3969                 goto out;
3970         }
3971
3972         ret = ocfs2_journal_access_di(handle, INODE_CACHE(t_inode), t_bh,
3973                                       OCFS2_JOURNAL_ACCESS_WRITE);
3974         if (ret) {
3975                 mlog_errno(ret);
3976                 goto out_commit;
3977         }
3978
3979         t_di->id2.i_data.id_count = s_di->id2.i_data.id_count;
3980         memcpy(t_di->id2.i_data.id_data, s_di->id2.i_data.id_data,
3981                le16_to_cpu(s_di->id2.i_data.id_count));
3982         spin_lock(&OCFS2_I(t_inode)->ip_lock);
3983         OCFS2_I(t_inode)->ip_dyn_features |= OCFS2_INLINE_DATA_FL;
3984         t_di->i_dyn_features = cpu_to_le16(OCFS2_I(t_inode)->ip_dyn_features);
3985         spin_unlock(&OCFS2_I(t_inode)->ip_lock);
3986
3987         ocfs2_journal_dirty(handle, t_bh);
3988
3989 out_commit:
3990         ocfs2_commit_trans(osb, handle);
3991 out:
3992         return ret;
3993 }
3994
3995 static int ocfs2_duplicate_extent_list(struct inode *s_inode,
3996                                 struct inode *t_inode,
3997                                 struct buffer_head *t_bh,
3998                                 struct ocfs2_caching_info *ref_ci,
3999                                 struct buffer_head *ref_root_bh,
4000                                 struct ocfs2_cached_dealloc_ctxt *dealloc)
4001 {
4002         int ret = 0;
4003         u32 p_cluster, num_clusters, clusters, cpos;
4004         loff_t size;
4005         unsigned int ext_flags;
4006         struct ocfs2_extent_tree et;
4007
4008         ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(t_inode), t_bh);
4009
4010         size = i_size_read(s_inode);
4011         clusters = ocfs2_clusters_for_bytes(s_inode->i_sb, size);
4012
4013         cpos = 0;
4014         while (cpos < clusters) {
4015                 ret = ocfs2_get_clusters(s_inode, cpos, &p_cluster,
4016                                          &num_clusters, &ext_flags);
4017
4018                 if (p_cluster) {
4019                         ret = ocfs2_add_refcounted_extent(t_inode, &et,
4020                                                           ref_ci, ref_root_bh,
4021                                                           cpos, p_cluster,
4022                                                           num_clusters,
4023                                                           ext_flags,
4024                                                           dealloc);
4025                         if (ret) {
4026                                 mlog_errno(ret);
4027                                 goto out;
4028                         }
4029                 }
4030
4031                 cpos += num_clusters;
4032         }
4033
4034 out:
4035         return ret;
4036 }
4037
4038 /*
4039  * change the new file's attributes to the src.
4040  *
4041  * reflink creates a snapshot of a file, that means the attributes
4042  * must be identical except for three exceptions - nlink, ino, and ctime.
4043  */
4044 static int ocfs2_complete_reflink(struct inode *s_inode,
4045                                   struct buffer_head *s_bh,
4046                                   struct inode *t_inode,
4047                                   struct buffer_head *t_bh,
4048                                   bool preserve)
4049 {
4050         int ret;
4051         handle_t *handle;
4052         struct ocfs2_dinode *s_di = (struct ocfs2_dinode *)s_bh->b_data;
4053         struct ocfs2_dinode *di = (struct ocfs2_dinode *)t_bh->b_data;
4054         loff_t size = i_size_read(s_inode);
4055
4056         handle = ocfs2_start_trans(OCFS2_SB(t_inode->i_sb),
4057                                    OCFS2_INODE_UPDATE_CREDITS);
4058         if (IS_ERR(handle)) {
4059                 ret = PTR_ERR(handle);
4060                 mlog_errno(ret);
4061                 return ret;
4062         }
4063
4064         ret = ocfs2_journal_access_di(handle, INODE_CACHE(t_inode), t_bh,
4065                                       OCFS2_JOURNAL_ACCESS_WRITE);
4066         if (ret) {
4067                 mlog_errno(ret);
4068                 goto out_commit;
4069         }
4070
4071         spin_lock(&OCFS2_I(t_inode)->ip_lock);
4072         OCFS2_I(t_inode)->ip_clusters = OCFS2_I(s_inode)->ip_clusters;
4073         OCFS2_I(t_inode)->ip_attr = OCFS2_I(s_inode)->ip_attr;
4074         OCFS2_I(t_inode)->ip_dyn_features = OCFS2_I(s_inode)->ip_dyn_features;
4075         spin_unlock(&OCFS2_I(t_inode)->ip_lock);
4076         i_size_write(t_inode, size);
4077         t_inode->i_blocks = s_inode->i_blocks;
4078
4079         di->i_xattr_inline_size = s_di->i_xattr_inline_size;
4080         di->i_clusters = s_di->i_clusters;
4081         di->i_size = s_di->i_size;
4082         di->i_dyn_features = s_di->i_dyn_features;
4083         di->i_attr = s_di->i_attr;
4084
4085         if (preserve) {
4086                 di->i_uid = s_di->i_uid;
4087                 di->i_gid = s_di->i_gid;
4088                 di->i_mode = s_di->i_mode;
4089
4090                 /*
4091                  * update time.
4092                  * we want mtime to appear identical to the source and
4093                  * update ctime.
4094                  */
4095                 t_inode->i_ctime = CURRENT_TIME;
4096
4097                 di->i_ctime = cpu_to_le64(t_inode->i_ctime.tv_sec);
4098                 di->i_ctime_nsec = cpu_to_le32(t_inode->i_ctime.tv_nsec);
4099
4100                 t_inode->i_mtime = s_inode->i_mtime;
4101                 di->i_mtime = s_di->i_mtime;
4102                 di->i_mtime_nsec = s_di->i_mtime_nsec;
4103         }
4104
4105         ocfs2_journal_dirty(handle, t_bh);
4106
4107 out_commit:
4108         ocfs2_commit_trans(OCFS2_SB(t_inode->i_sb), handle);
4109         return ret;
4110 }
4111
4112 static int ocfs2_create_reflink_node(struct inode *s_inode,
4113                                      struct buffer_head *s_bh,
4114                                      struct inode *t_inode,
4115                                      struct buffer_head *t_bh,
4116                                      bool preserve)
4117 {
4118         int ret;
4119         struct buffer_head *ref_root_bh = NULL;
4120         struct ocfs2_cached_dealloc_ctxt dealloc;
4121         struct ocfs2_super *osb = OCFS2_SB(s_inode->i_sb);
4122         struct ocfs2_refcount_block *rb;
4123         struct ocfs2_dinode *di = (struct ocfs2_dinode *)s_bh->b_data;
4124         struct ocfs2_refcount_tree *ref_tree;
4125
4126         ocfs2_init_dealloc_ctxt(&dealloc);
4127
4128         ret = ocfs2_set_refcount_tree(t_inode, t_bh,
4129                                       le64_to_cpu(di->i_refcount_loc));
4130         if (ret) {
4131                 mlog_errno(ret);
4132                 goto out;
4133         }
4134
4135         if (OCFS2_I(s_inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
4136                 ret = ocfs2_duplicate_inline_data(s_inode, s_bh,
4137                                                   t_inode, t_bh);
4138                 if (ret)
4139                         mlog_errno(ret);
4140                 goto out;
4141         }
4142
4143         ret = ocfs2_lock_refcount_tree(osb, le64_to_cpu(di->i_refcount_loc),
4144                                        1, &ref_tree, &ref_root_bh);
4145         if (ret) {
4146                 mlog_errno(ret);
4147                 goto out;
4148         }
4149         rb = (struct ocfs2_refcount_block *)ref_root_bh->b_data;
4150
4151         ret = ocfs2_duplicate_extent_list(s_inode, t_inode, t_bh,
4152                                           &ref_tree->rf_ci, ref_root_bh,
4153                                           &dealloc);
4154         if (ret) {
4155                 mlog_errno(ret);
4156                 goto out_unlock_refcount;
4157         }
4158
4159 out_unlock_refcount:
4160         ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
4161         brelse(ref_root_bh);
4162 out:
4163         if (ocfs2_dealloc_has_cluster(&dealloc)) {
4164                 ocfs2_schedule_truncate_log_flush(osb, 1);
4165                 ocfs2_run_deallocs(osb, &dealloc);
4166         }
4167
4168         return ret;
4169 }
4170
4171 static int __ocfs2_reflink(struct dentry *old_dentry,
4172                            struct buffer_head *old_bh,
4173                            struct inode *new_inode,
4174                            bool preserve)
4175 {
4176         int ret;
4177         struct inode *inode = old_dentry->d_inode;
4178         struct buffer_head *new_bh = NULL;
4179
4180         ret = filemap_fdatawrite(inode->i_mapping);
4181         if (ret) {
4182                 mlog_errno(ret);
4183                 goto out;
4184         }
4185
4186         ret = ocfs2_attach_refcount_tree(inode, old_bh);
4187         if (ret) {
4188                 mlog_errno(ret);
4189                 goto out;
4190         }
4191
4192         mutex_lock(&new_inode->i_mutex);
4193         ret = ocfs2_inode_lock(new_inode, &new_bh, 1);
4194         if (ret) {
4195                 mlog_errno(ret);
4196                 goto out_unlock;
4197         }
4198
4199         ret = ocfs2_create_reflink_node(inode, old_bh,
4200                                         new_inode, new_bh, preserve);
4201         if (ret) {
4202                 mlog_errno(ret);
4203                 goto inode_unlock;
4204         }
4205
4206         if (OCFS2_I(inode)->ip_dyn_features & OCFS2_HAS_XATTR_FL) {
4207                 ret = ocfs2_reflink_xattrs(inode, old_bh,
4208                                            new_inode, new_bh,
4209                                            preserve);
4210                 if (ret) {
4211                         mlog_errno(ret);
4212                         goto inode_unlock;
4213                 }
4214         }
4215
4216         ret = ocfs2_complete_reflink(inode, old_bh,
4217                                      new_inode, new_bh, preserve);
4218         if (ret)
4219                 mlog_errno(ret);
4220
4221 inode_unlock:
4222         ocfs2_inode_unlock(new_inode, 1);
4223         brelse(new_bh);
4224 out_unlock:
4225         mutex_unlock(&new_inode->i_mutex);
4226 out:
4227         if (!ret) {
4228                 ret = filemap_fdatawait(inode->i_mapping);
4229                 if (ret)
4230                         mlog_errno(ret);
4231         }
4232         return ret;
4233 }
4234
4235 static int ocfs2_reflink(struct dentry *old_dentry, struct inode *dir,
4236                          struct dentry *new_dentry, bool preserve)
4237 {
4238         int error;
4239         struct inode *inode = old_dentry->d_inode;
4240         struct buffer_head *old_bh = NULL;
4241         struct inode *new_orphan_inode = NULL;
4242
4243         if (!ocfs2_refcount_tree(OCFS2_SB(inode->i_sb)))
4244                 return -EOPNOTSUPP;
4245
4246         error = ocfs2_create_inode_in_orphan(dir, inode->i_mode,
4247                                              &new_orphan_inode);
4248         if (error) {
4249                 mlog_errno(error);
4250                 goto out;
4251         }
4252
4253         error = ocfs2_inode_lock(inode, &old_bh, 1);
4254         if (error) {
4255                 mlog_errno(error);
4256                 goto out;
4257         }
4258
4259         down_write(&OCFS2_I(inode)->ip_xattr_sem);
4260         down_write(&OCFS2_I(inode)->ip_alloc_sem);
4261         error = __ocfs2_reflink(old_dentry, old_bh,
4262                                 new_orphan_inode, preserve);
4263         up_write(&OCFS2_I(inode)->ip_alloc_sem);
4264         up_write(&OCFS2_I(inode)->ip_xattr_sem);
4265
4266         ocfs2_inode_unlock(inode, 1);
4267         brelse(old_bh);
4268
4269         if (error) {
4270                 mlog_errno(error);
4271                 goto out;
4272         }
4273
4274         /* If the security isn't preserved, we need to re-initialize them. */
4275         if (!preserve) {
4276                 error = ocfs2_init_security_and_acl(dir, new_orphan_inode);
4277                 if (error)
4278                         mlog_errno(error);
4279         }
4280 out:
4281         if (!error) {
4282                 error = ocfs2_mv_orphaned_inode_to_new(dir, new_orphan_inode,
4283                                                        new_dentry);
4284                 if (error)
4285                         mlog_errno(error);
4286         }
4287
4288         if (new_orphan_inode) {
4289                 /*
4290                  * We need to open_unlock the inode no matter whether we
4291                  * succeed or not, so that other nodes can delete it later.
4292                  */
4293                 ocfs2_open_unlock(new_orphan_inode);
4294                 if (error)
4295                         iput(new_orphan_inode);
4296         }
4297
4298         return error;
4299 }
4300
4301 /*
4302  * Below here are the bits used by OCFS2_IOC_REFLINK() to fake
4303  * sys_reflink().  This will go away when vfs_reflink() exists in
4304  * fs/namei.c.
4305  */
4306
4307 /* copied from may_create in VFS. */
4308 static inline int ocfs2_may_create(struct inode *dir, struct dentry *child)
4309 {
4310         if (child->d_inode)
4311                 return -EEXIST;
4312         if (IS_DEADDIR(dir))
4313                 return -ENOENT;
4314         return inode_permission(dir, MAY_WRITE | MAY_EXEC);
4315 }
4316
4317 /* copied from user_path_parent. */
4318 static int ocfs2_user_path_parent(const char __user *path,
4319                                   struct nameidata *nd, char **name)
4320 {
4321         char *s = getname(path);
4322         int error;
4323
4324         if (IS_ERR(s))
4325                 return PTR_ERR(s);
4326
4327         error = path_lookup(s, LOOKUP_PARENT, nd);
4328         if (error)
4329                 putname(s);
4330         else
4331                 *name = s;
4332
4333         return error;
4334 }
4335
4336 /**
4337  * ocfs2_vfs_reflink - Create a reference-counted link
4338  *
4339  * @old_dentry:        source dentry + inode
4340  * @dir:       directory to create the target
4341  * @new_dentry:        target dentry
4342  * @preserve:  if true, preserve all file attributes
4343  */
4344 static int ocfs2_vfs_reflink(struct dentry *old_dentry, struct inode *dir,
4345                              struct dentry *new_dentry, bool preserve)
4346 {
4347         struct inode *inode = old_dentry->d_inode;
4348         int error;
4349
4350         if (!inode)
4351                 return -ENOENT;
4352
4353         error = ocfs2_may_create(dir, new_dentry);
4354         if (error)
4355                 return error;
4356
4357         if (dir->i_sb != inode->i_sb)
4358                 return -EXDEV;
4359
4360         /*
4361          * A reflink to an append-only or immutable file cannot be created.
4362          */
4363         if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
4364                 return -EPERM;
4365
4366         /* Only regular files can be reflinked. */
4367         if (!S_ISREG(inode->i_mode))
4368                 return -EPERM;
4369
4370         /*
4371          * If the caller wants to preserve ownership, they require the
4372          * rights to do so.
4373          */
4374         if (preserve) {
4375                 if ((current_fsuid() != inode->i_uid) && !capable(CAP_CHOWN))
4376                         return -EPERM;
4377                 if (!in_group_p(inode->i_gid) && !capable(CAP_CHOWN))
4378                         return -EPERM;
4379         }
4380
4381         /*
4382          * If the caller is modifying any aspect of the attributes, they
4383          * are not creating a snapshot.  They need read permission on the
4384          * file.
4385          */
4386         if (!preserve) {
4387                 error = inode_permission(inode, MAY_READ);
4388                 if (error)
4389                         return error;
4390         }
4391
4392         mutex_lock(&inode->i_mutex);
4393         dquot_initialize(dir);
4394         error = ocfs2_reflink(old_dentry, dir, new_dentry, preserve);
4395         mutex_unlock(&inode->i_mutex);
4396         if (!error)
4397                 fsnotify_create(dir, new_dentry);
4398         return error;
4399 }
4400 /*
4401  * Most codes are copied from sys_linkat.
4402  */
4403 int ocfs2_reflink_ioctl(struct inode *inode,
4404                         const char __user *oldname,
4405                         const char __user *newname,
4406                         bool preserve)
4407 {
4408         struct dentry *new_dentry;
4409         struct nameidata nd;
4410         struct path old_path;
4411         int error;
4412         char *to = NULL;
4413
4414         if (!ocfs2_refcount_tree(OCFS2_SB(inode->i_sb)))
4415                 return -EOPNOTSUPP;
4416
4417         error = user_path_at(AT_FDCWD, oldname, 0, &old_path);
4418         if (error) {
4419                 mlog_errno(error);
4420                 return error;
4421         }
4422
4423         error = ocfs2_user_path_parent(newname, &nd, &to);
4424         if (error) {
4425                 mlog_errno(error);
4426                 goto out;
4427         }
4428
4429         error = -EXDEV;
4430         if (old_path.mnt != nd.path.mnt)
4431                 goto out_release;
4432         new_dentry = lookup_create(&nd, 0);
4433         error = PTR_ERR(new_dentry);
4434         if (IS_ERR(new_dentry)) {
4435                 mlog_errno(error);
4436                 goto out_unlock;
4437         }
4438
4439         error = mnt_want_write(nd.path.mnt);
4440         if (error) {
4441                 mlog_errno(error);
4442                 goto out_dput;
4443         }
4444
4445         error = ocfs2_vfs_reflink(old_path.dentry,
4446                                   nd.path.dentry->d_inode,
4447                                   new_dentry, preserve);
4448         mnt_drop_write(nd.path.mnt);
4449 out_dput:
4450         dput(new_dentry);
4451 out_unlock:
4452         mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
4453 out_release:
4454         path_put(&nd.path);
4455         putname(to);
4456 out:
4457         path_put(&old_path);
4458
4459         return error;
4460 }