linux/fs/ocfs2/refcounttree.c
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   1/* -*- mode: c; c-basic-offset: 8; -*-
   2 * vim: noexpandtab sw=8 ts=8 sts=0:
   3 *
   4 * refcounttree.c
   5 *
   6 * Copyright (C) 2009 Oracle.  All rights reserved.
   7 *
   8 * This program is free software; you can redistribute it and/or
   9 * modify it under the terms of the GNU General Public
  10 * License version 2 as published by the Free Software Foundation.
  11 *
  12 * This program is distributed in the hope that it will be useful,
  13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 * General Public License for more details.
  16 */
  17
  18#include <linux/sort.h>
  19#include <cluster/masklog.h>
  20#include "ocfs2.h"
  21#include "inode.h"
  22#include "alloc.h"
  23#include "suballoc.h"
  24#include "journal.h"
  25#include "uptodate.h"
  26#include "super.h"
  27#include "buffer_head_io.h"
  28#include "blockcheck.h"
  29#include "refcounttree.h"
  30#include "sysfile.h"
  31#include "dlmglue.h"
  32#include "extent_map.h"
  33#include "aops.h"
  34#include "xattr.h"
  35#include "namei.h"
  36#include "ocfs2_trace.h"
  37
  38#include <linux/bio.h>
  39#include <linux/blkdev.h>
  40#include <linux/slab.h>
  41#include <linux/writeback.h>
  42#include <linux/pagevec.h>
  43#include <linux/swap.h>
  44#include <linux/security.h>
  45#include <linux/fsnotify.h>
  46#include <linux/quotaops.h>
  47#include <linux/namei.h>
  48#include <linux/mount.h>
  49#include <linux/posix_acl.h>
  50
  51struct ocfs2_cow_context {
  52        struct inode *inode;
  53        u32 cow_start;
  54        u32 cow_len;
  55        struct ocfs2_extent_tree data_et;
  56        struct ocfs2_refcount_tree *ref_tree;
  57        struct buffer_head *ref_root_bh;
  58        struct ocfs2_alloc_context *meta_ac;
  59        struct ocfs2_alloc_context *data_ac;
  60        struct ocfs2_cached_dealloc_ctxt dealloc;
  61        void *cow_object;
  62        struct ocfs2_post_refcount *post_refcount;
  63        int extra_credits;
  64        int (*get_clusters)(struct ocfs2_cow_context *context,
  65                            u32 v_cluster, u32 *p_cluster,
  66                            u32 *num_clusters,
  67                            unsigned int *extent_flags);
  68        int (*cow_duplicate_clusters)(handle_t *handle,
  69                                      struct inode *inode,
  70                                      u32 cpos, u32 old_cluster,
  71                                      u32 new_cluster, u32 new_len);
  72};
  73
  74static inline struct ocfs2_refcount_tree *
  75cache_info_to_refcount(struct ocfs2_caching_info *ci)
  76{
  77        return container_of(ci, struct ocfs2_refcount_tree, rf_ci);
  78}
  79
  80static int ocfs2_validate_refcount_block(struct super_block *sb,
  81                                         struct buffer_head *bh)
  82{
  83        int rc;
  84        struct ocfs2_refcount_block *rb =
  85                (struct ocfs2_refcount_block *)bh->b_data;
  86
  87        trace_ocfs2_validate_refcount_block((unsigned long long)bh->b_blocknr);
  88
  89        BUG_ON(!buffer_uptodate(bh));
  90
  91        /*
  92         * If the ecc fails, we return the error but otherwise
  93         * leave the filesystem running.  We know any error is
  94         * local to this block.
  95         */
  96        rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &rb->rf_check);
  97        if (rc) {
  98                mlog(ML_ERROR, "Checksum failed for refcount block %llu\n",
  99                     (unsigned long long)bh->b_blocknr);
 100                return rc;
 101        }
 102
 103
 104        if (!OCFS2_IS_VALID_REFCOUNT_BLOCK(rb)) {
 105                ocfs2_error(sb,
 106                            "Refcount block #%llu has bad signature %.*s",
 107                            (unsigned long long)bh->b_blocknr, 7,
 108                            rb->rf_signature);
 109                return -EINVAL;
 110        }
 111
 112        if (le64_to_cpu(rb->rf_blkno) != bh->b_blocknr) {
 113                ocfs2_error(sb,
 114                            "Refcount block #%llu has an invalid rf_blkno "
 115                            "of %llu",
 116                            (unsigned long long)bh->b_blocknr,
 117                            (unsigned long long)le64_to_cpu(rb->rf_blkno));
 118                return -EINVAL;
 119        }
 120
 121        if (le32_to_cpu(rb->rf_fs_generation) != OCFS2_SB(sb)->fs_generation) {
 122                ocfs2_error(sb,
 123                            "Refcount block #%llu has an invalid "
 124                            "rf_fs_generation of #%u",
 125                            (unsigned long long)bh->b_blocknr,
 126                            le32_to_cpu(rb->rf_fs_generation));
 127                return -EINVAL;
 128        }
 129
 130        return 0;
 131}
 132
 133static 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
 150static 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
 157static struct super_block *
 158ocfs2_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
 165static 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
 172static 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
 179static 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
 186static 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
 193static 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
 202static struct ocfs2_refcount_tree *
 203ocfs2_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. */
 223static 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
 253static 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
 261static inline void
 262ocfs2_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
 270static 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
 278static 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
 286static inline void
 287ocfs2_refcount_tree_get(struct ocfs2_refcount_tree *tree)
 288{
 289        kref_get(&tree->rf_getcnt);
 290}
 291
 292static inline void
 293ocfs2_refcount_tree_put(struct ocfs2_refcount_tree *tree)
 294{
 295        kref_put(&tree->rf_getcnt, ocfs2_kref_remove_refcount_tree);
 296}
 297
 298static 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
 307static 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
 316static struct ocfs2_refcount_tree*
 317ocfs2_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
 332static 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
 389out:
 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
 403static 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);
 420out:
 421        return ret;
 422}
 423
 424static 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
 440out:
 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 */
 452int 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
 462again:
 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        }
 521out:
 522        brelse(ref_root_bh);
 523        return ret;
 524}
 525
 526void 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
 538void ocfs2_purge_refcount_trees(struct ocfs2_super *osb)
 539{
 540        struct rb_node *node;
 541        struct ocfs2_refcount_tree *tree;
 542        struct rb_root *root = &osb->osb_rf_lock_tree;
 543
 544        while ((node = rb_last(root)) != NULL) {
 545                tree = rb_entry(node, struct ocfs2_refcount_tree, rf_node);
 546
 547                trace_ocfs2_purge_refcount_trees(
 548                                (unsigned long long) tree->rf_blkno);
 549
 550                rb_erase(&tree->rf_node, root);
 551                ocfs2_free_refcount_tree(tree);
 552        }
 553}
 554
 555/*
 556 * Create a refcount tree for an inode.
 557 * We take for granted that the inode is already locked.
 558 */
 559static int ocfs2_create_refcount_tree(struct inode *inode,
 560                                      struct buffer_head *di_bh)
 561{
 562        int ret;
 563        handle_t *handle = NULL;
 564        struct ocfs2_alloc_context *meta_ac = NULL;
 565        struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
 566        struct ocfs2_inode_info *oi = OCFS2_I(inode);
 567        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 568        struct buffer_head *new_bh = NULL;
 569        struct ocfs2_refcount_block *rb;
 570        struct ocfs2_refcount_tree *new_tree = NULL, *tree = NULL;
 571        u16 suballoc_bit_start;
 572        u32 num_got;
 573        u64 suballoc_loc, first_blkno;
 574
 575        BUG_ON(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL);
 576
 577        trace_ocfs2_create_refcount_tree(
 578                (unsigned long long)OCFS2_I(inode)->ip_blkno);
 579
 580        ret = ocfs2_reserve_new_metadata_blocks(osb, 1, &meta_ac);
 581        if (ret) {
 582                mlog_errno(ret);
 583                goto out;
 584        }
 585
 586        handle = ocfs2_start_trans(osb, OCFS2_REFCOUNT_TREE_CREATE_CREDITS);
 587        if (IS_ERR(handle)) {
 588                ret = PTR_ERR(handle);
 589                mlog_errno(ret);
 590                goto out;
 591        }
 592
 593        ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
 594                                      OCFS2_JOURNAL_ACCESS_WRITE);
 595        if (ret) {
 596                mlog_errno(ret);
 597                goto out_commit;
 598        }
 599
 600        ret = ocfs2_claim_metadata(handle, meta_ac, 1, &suballoc_loc,
 601                                   &suballoc_bit_start, &num_got,
 602                                   &first_blkno);
 603        if (ret) {
 604                mlog_errno(ret);
 605                goto out_commit;
 606        }
 607
 608        new_tree = ocfs2_allocate_refcount_tree(osb, first_blkno);
 609        if (!new_tree) {
 610                ret = -ENOMEM;
 611                mlog_errno(ret);
 612                goto out_commit;
 613        }
 614
 615        new_bh = sb_getblk(inode->i_sb, first_blkno);
 616        if (!new_bh) {
 617                ret = -ENOMEM;
 618                mlog_errno(ret);
 619                goto out_commit;
 620        }
 621        ocfs2_set_new_buffer_uptodate(&new_tree->rf_ci, new_bh);
 622
 623        ret = ocfs2_journal_access_rb(handle, &new_tree->rf_ci, new_bh,
 624                                      OCFS2_JOURNAL_ACCESS_CREATE);
 625        if (ret) {
 626                mlog_errno(ret);
 627                goto out_commit;
 628        }
 629
 630        /* Initialize ocfs2_refcount_block. */
 631        rb = (struct ocfs2_refcount_block *)new_bh->b_data;
 632        memset(rb, 0, inode->i_sb->s_blocksize);
 633        strcpy((void *)rb, OCFS2_REFCOUNT_BLOCK_SIGNATURE);
 634        rb->rf_suballoc_slot = cpu_to_le16(meta_ac->ac_alloc_slot);
 635        rb->rf_suballoc_loc = cpu_to_le64(suballoc_loc);
 636        rb->rf_suballoc_bit = cpu_to_le16(suballoc_bit_start);
 637        rb->rf_fs_generation = cpu_to_le32(osb->fs_generation);
 638        rb->rf_blkno = cpu_to_le64(first_blkno);
 639        rb->rf_count = cpu_to_le32(1);
 640        rb->rf_records.rl_count =
 641                        cpu_to_le16(ocfs2_refcount_recs_per_rb(osb->sb));
 642        spin_lock(&osb->osb_lock);
 643        rb->rf_generation = osb->s_next_generation++;
 644        spin_unlock(&osb->osb_lock);
 645
 646        ocfs2_journal_dirty(handle, new_bh);
 647
 648        spin_lock(&oi->ip_lock);
 649        oi->ip_dyn_features |= OCFS2_HAS_REFCOUNT_FL;
 650        di->i_dyn_features = cpu_to_le16(oi->ip_dyn_features);
 651        di->i_refcount_loc = cpu_to_le64(first_blkno);
 652        spin_unlock(&oi->ip_lock);
 653
 654        trace_ocfs2_create_refcount_tree_blkno((unsigned long long)first_blkno);
 655
 656        ocfs2_journal_dirty(handle, di_bh);
 657
 658        /*
 659         * We have to init the tree lock here since it will use
 660         * the generation number to create it.
 661         */
 662        new_tree->rf_generation = le32_to_cpu(rb->rf_generation);
 663        ocfs2_init_refcount_tree_lock(osb, new_tree, first_blkno,
 664                                      new_tree->rf_generation);
 665
 666        spin_lock(&osb->osb_lock);
 667        tree = ocfs2_find_refcount_tree(osb, first_blkno);
 668
 669        /*
 670         * We've just created a new refcount tree in this block.  If
 671         * we found a refcount tree on the ocfs2_super, it must be
 672         * one we just deleted.  We free the old tree before
 673         * inserting the new tree.
 674         */
 675        BUG_ON(tree && tree->rf_generation == new_tree->rf_generation);
 676        if (tree)
 677                ocfs2_erase_refcount_tree_from_list_no_lock(osb, tree);
 678        ocfs2_insert_refcount_tree(osb, new_tree);
 679        spin_unlock(&osb->osb_lock);
 680        new_tree = NULL;
 681        if (tree)
 682                ocfs2_refcount_tree_put(tree);
 683
 684out_commit:
 685        ocfs2_commit_trans(osb, handle);
 686
 687out:
 688        if (new_tree) {
 689                ocfs2_metadata_cache_exit(&new_tree->rf_ci);
 690                kfree(new_tree);
 691        }
 692
 693        brelse(new_bh);
 694        if (meta_ac)
 695                ocfs2_free_alloc_context(meta_ac);
 696
 697        return ret;
 698}
 699
 700static int ocfs2_set_refcount_tree(struct inode *inode,
 701                                   struct buffer_head *di_bh,
 702                                   u64 refcount_loc)
 703{
 704        int ret;
 705        handle_t *handle = NULL;
 706        struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
 707        struct ocfs2_inode_info *oi = OCFS2_I(inode);
 708        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 709        struct buffer_head *ref_root_bh = NULL;
 710        struct ocfs2_refcount_block *rb;
 711        struct ocfs2_refcount_tree *ref_tree;
 712
 713        BUG_ON(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL);
 714
 715        ret = ocfs2_lock_refcount_tree(osb, refcount_loc, 1,
 716                                       &ref_tree, &ref_root_bh);
 717        if (ret) {
 718                mlog_errno(ret);
 719                return ret;
 720        }
 721
 722        handle = ocfs2_start_trans(osb, OCFS2_REFCOUNT_TREE_SET_CREDITS);
 723        if (IS_ERR(handle)) {
 724                ret = PTR_ERR(handle);
 725                mlog_errno(ret);
 726                goto out;
 727        }
 728
 729        ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
 730                                      OCFS2_JOURNAL_ACCESS_WRITE);
 731        if (ret) {
 732                mlog_errno(ret);
 733                goto out_commit;
 734        }
 735
 736        ret = ocfs2_journal_access_rb(handle, &ref_tree->rf_ci, ref_root_bh,
 737                                      OCFS2_JOURNAL_ACCESS_WRITE);
 738        if (ret) {
 739                mlog_errno(ret);
 740                goto out_commit;
 741        }
 742
 743        rb = (struct ocfs2_refcount_block *)ref_root_bh->b_data;
 744        le32_add_cpu(&rb->rf_count, 1);
 745
 746        ocfs2_journal_dirty(handle, ref_root_bh);
 747
 748        spin_lock(&oi->ip_lock);
 749        oi->ip_dyn_features |= OCFS2_HAS_REFCOUNT_FL;
 750        di->i_dyn_features = cpu_to_le16(oi->ip_dyn_features);
 751        di->i_refcount_loc = cpu_to_le64(refcount_loc);
 752        spin_unlock(&oi->ip_lock);
 753        ocfs2_journal_dirty(handle, di_bh);
 754
 755out_commit:
 756        ocfs2_commit_trans(osb, handle);
 757out:
 758        ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
 759        brelse(ref_root_bh);
 760
 761        return ret;
 762}
 763
 764int ocfs2_remove_refcount_tree(struct inode *inode, struct buffer_head *di_bh)
 765{
 766        int ret, delete_tree = 0;
 767        handle_t *handle = NULL;
 768        struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
 769        struct ocfs2_inode_info *oi = OCFS2_I(inode);
 770        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 771        struct ocfs2_refcount_block *rb;
 772        struct inode *alloc_inode = NULL;
 773        struct buffer_head *alloc_bh = NULL;
 774        struct buffer_head *blk_bh = NULL;
 775        struct ocfs2_refcount_tree *ref_tree;
 776        int credits = OCFS2_REFCOUNT_TREE_REMOVE_CREDITS;
 777        u64 blk = 0, bg_blkno = 0, ref_blkno = le64_to_cpu(di->i_refcount_loc);
 778        u16 bit = 0;
 779
 780        if (!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL))
 781                return 0;
 782
 783        BUG_ON(!ref_blkno);
 784        ret = ocfs2_lock_refcount_tree(osb, ref_blkno, 1, &ref_tree, &blk_bh);
 785        if (ret) {
 786                mlog_errno(ret);
 787                return ret;
 788        }
 789
 790        rb = (struct ocfs2_refcount_block *)blk_bh->b_data;
 791
 792        /*
 793         * If we are the last user, we need to free the block.
 794         * So lock the allocator ahead.
 795         */
 796        if (le32_to_cpu(rb->rf_count) == 1) {
 797                blk = le64_to_cpu(rb->rf_blkno);
 798                bit = le16_to_cpu(rb->rf_suballoc_bit);
 799                if (rb->rf_suballoc_loc)
 800                        bg_blkno = le64_to_cpu(rb->rf_suballoc_loc);
 801                else
 802                        bg_blkno = ocfs2_which_suballoc_group(blk, bit);
 803
 804                alloc_inode = ocfs2_get_system_file_inode(osb,
 805                                        EXTENT_ALLOC_SYSTEM_INODE,
 806                                        le16_to_cpu(rb->rf_suballoc_slot));
 807                if (!alloc_inode) {
 808                        ret = -ENOMEM;
 809                        mlog_errno(ret);
 810                        goto out;
 811                }
 812                mutex_lock(&alloc_inode->i_mutex);
 813
 814                ret = ocfs2_inode_lock(alloc_inode, &alloc_bh, 1);
 815                if (ret) {
 816                        mlog_errno(ret);
 817                        goto out_mutex;
 818                }
 819
 820                credits += OCFS2_SUBALLOC_FREE;
 821        }
 822
 823        handle = ocfs2_start_trans(osb, credits);
 824        if (IS_ERR(handle)) {
 825                ret = PTR_ERR(handle);
 826                mlog_errno(ret);
 827                goto out_unlock;
 828        }
 829
 830        ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
 831                                      OCFS2_JOURNAL_ACCESS_WRITE);
 832        if (ret) {
 833                mlog_errno(ret);
 834                goto out_commit;
 835        }
 836
 837        ret = ocfs2_journal_access_rb(handle, &ref_tree->rf_ci, blk_bh,
 838                                      OCFS2_JOURNAL_ACCESS_WRITE);
 839        if (ret) {
 840                mlog_errno(ret);
 841                goto out_commit;
 842        }
 843
 844        spin_lock(&oi->ip_lock);
 845        oi->ip_dyn_features &= ~OCFS2_HAS_REFCOUNT_FL;
 846        di->i_dyn_features = cpu_to_le16(oi->ip_dyn_features);
 847        di->i_refcount_loc = 0;
 848        spin_unlock(&oi->ip_lock);
 849        ocfs2_journal_dirty(handle, di_bh);
 850
 851        le32_add_cpu(&rb->rf_count , -1);
 852        ocfs2_journal_dirty(handle, blk_bh);
 853
 854        if (!rb->rf_count) {
 855                delete_tree = 1;
 856                ocfs2_erase_refcount_tree_from_list(osb, ref_tree);
 857                ret = ocfs2_free_suballoc_bits(handle, alloc_inode,
 858                                               alloc_bh, bit, bg_blkno, 1);
 859                if (ret)
 860                        mlog_errno(ret);
 861        }
 862
 863out_commit:
 864        ocfs2_commit_trans(osb, handle);
 865out_unlock:
 866        if (alloc_inode) {
 867                ocfs2_inode_unlock(alloc_inode, 1);
 868                brelse(alloc_bh);
 869        }
 870out_mutex:
 871        if (alloc_inode) {
 872                mutex_unlock(&alloc_inode->i_mutex);
 873                iput(alloc_inode);
 874        }
 875out:
 876        ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
 877        if (delete_tree)
 878                ocfs2_refcount_tree_put(ref_tree);
 879        brelse(blk_bh);
 880
 881        return ret;
 882}
 883
 884static void ocfs2_find_refcount_rec_in_rl(struct ocfs2_caching_info *ci,
 885                                          struct buffer_head *ref_leaf_bh,
 886                                          u64 cpos, unsigned int len,
 887                                          struct ocfs2_refcount_rec *ret_rec,
 888                                          int *index)
 889{
 890        int i = 0;
 891        struct ocfs2_refcount_block *rb =
 892                (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
 893        struct ocfs2_refcount_rec *rec = NULL;
 894
 895        for (; i < le16_to_cpu(rb->rf_records.rl_used); i++) {
 896                rec = &rb->rf_records.rl_recs[i];
 897
 898                if (le64_to_cpu(rec->r_cpos) +
 899                    le32_to_cpu(rec->r_clusters) <= cpos)
 900                        continue;
 901                else if (le64_to_cpu(rec->r_cpos) > cpos)
 902                        break;
 903
 904                /* ok, cpos fail in this rec. Just return. */
 905                if (ret_rec)
 906                        *ret_rec = *rec;
 907                goto out;
 908        }
 909
 910        if (ret_rec) {
 911                /* We meet with a hole here, so fake the rec. */
 912                ret_rec->r_cpos = cpu_to_le64(cpos);
 913                ret_rec->r_refcount = 0;
 914                if (i < le16_to_cpu(rb->rf_records.rl_used) &&
 915                    le64_to_cpu(rec->r_cpos) < cpos + len)
 916                        ret_rec->r_clusters =
 917                                cpu_to_le32(le64_to_cpu(rec->r_cpos) - cpos);
 918                else
 919                        ret_rec->r_clusters = cpu_to_le32(len);
 920        }
 921
 922out:
 923        *index = i;
 924}
 925
 926/*
 927 * Try to remove refcount tree. The mechanism is:
 928 * 1) Check whether i_clusters == 0, if no, exit.
 929 * 2) check whether we have i_xattr_loc in dinode. if yes, exit.
 930 * 3) Check whether we have inline xattr stored outside, if yes, exit.
 931 * 4) Remove the tree.
 932 */
 933int ocfs2_try_remove_refcount_tree(struct inode *inode,
 934                                   struct buffer_head *di_bh)
 935{
 936        int ret;
 937        struct ocfs2_inode_info *oi = OCFS2_I(inode);
 938        struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
 939
 940        down_write(&oi->ip_xattr_sem);
 941        down_write(&oi->ip_alloc_sem);
 942
 943        if (oi->ip_clusters)
 944                goto out;
 945
 946        if ((oi->ip_dyn_features & OCFS2_HAS_XATTR_FL) && di->i_xattr_loc)
 947                goto out;
 948
 949        if (oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL &&
 950            ocfs2_has_inline_xattr_value_outside(inode, di))
 951                goto out;
 952
 953        ret = ocfs2_remove_refcount_tree(inode, di_bh);
 954        if (ret)
 955                mlog_errno(ret);
 956out:
 957        up_write(&oi->ip_alloc_sem);
 958        up_write(&oi->ip_xattr_sem);
 959        return 0;
 960}
 961
 962/*
 963 * Find the end range for a leaf refcount block indicated by
 964 * el->l_recs[index].e_blkno.
 965 */
 966static int ocfs2_get_refcount_cpos_end(struct ocfs2_caching_info *ci,
 967                                       struct buffer_head *ref_root_bh,
 968                                       struct ocfs2_extent_block *eb,
 969                                       struct ocfs2_extent_list *el,
 970                                       int index,  u32 *cpos_end)
 971{
 972        int ret, i, subtree_root;
 973        u32 cpos;
 974        u64 blkno;
 975        struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
 976        struct ocfs2_path *left_path = NULL, *right_path = NULL;
 977        struct ocfs2_extent_tree et;
 978        struct ocfs2_extent_list *tmp_el;
 979
 980        if (index < le16_to_cpu(el->l_next_free_rec) - 1) {
 981                /*
 982                 * We have a extent rec after index, so just use the e_cpos
 983                 * of the next extent rec.
 984                 */
 985                *cpos_end = le32_to_cpu(el->l_recs[index+1].e_cpos);
 986                return 0;
 987        }
 988
 989        if (!eb || (eb && !eb->h_next_leaf_blk)) {
 990                /*
 991                 * We are the last extent rec, so any high cpos should
 992                 * be stored in this leaf refcount block.
 993                 */
 994                *cpos_end = UINT_MAX;
 995                return 0;
 996        }
 997
 998        /*
 999         * If the extent block isn't the last one, we have to find
1000         * the subtree root between this extent block and the next
1001         * leaf extent block and get the corresponding e_cpos from
1002         * the subroot. Otherwise we may corrupt the b-tree.
1003         */
1004        ocfs2_init_refcount_extent_tree(&et, ci, ref_root_bh);
1005
1006        left_path = ocfs2_new_path_from_et(&et);
1007        if (!left_path) {
1008                ret = -ENOMEM;
1009                mlog_errno(ret);
1010                goto out;
1011        }
1012
1013        cpos = le32_to_cpu(eb->h_list.l_recs[index].e_cpos);
1014        ret = ocfs2_find_path(ci, left_path, cpos);
1015        if (ret) {
1016                mlog_errno(ret);
1017                goto out;
1018        }
1019
1020        right_path = ocfs2_new_path_from_path(left_path);
1021        if (!right_path) {
1022                ret = -ENOMEM;
1023                mlog_errno(ret);
1024                goto out;
1025        }
1026
1027        ret = ocfs2_find_cpos_for_right_leaf(sb, left_path, &cpos);
1028        if (ret) {
1029                mlog_errno(ret);
1030                goto out;
1031        }
1032
1033        ret = ocfs2_find_path(ci, right_path, cpos);
1034        if (ret) {
1035                mlog_errno(ret);
1036                goto out;
1037        }
1038
1039        subtree_root = ocfs2_find_subtree_root(&et, left_path,
1040                                               right_path);
1041
1042        tmp_el = left_path->p_node[subtree_root].el;
1043        blkno = left_path->p_node[subtree_root+1].bh->b_blocknr;
1044        for (i = 0; i < le16_to_cpu(tmp_el->l_next_free_rec); i++) {
1045                if (le64_to_cpu(tmp_el->l_recs[i].e_blkno) == blkno) {
1046                        *cpos_end = le32_to_cpu(tmp_el->l_recs[i+1].e_cpos);
1047                        break;
1048                }
1049        }
1050
1051        BUG_ON(i == le16_to_cpu(tmp_el->l_next_free_rec));
1052
1053out:
1054        ocfs2_free_path(left_path);
1055        ocfs2_free_path(right_path);
1056        return ret;
1057}
1058
1059/*
1060 * Given a cpos and len, try to find the refcount record which contains cpos.
1061 * 1. If cpos can be found in one refcount record, return the record.
1062 * 2. If cpos can't be found, return a fake record which start from cpos
1063 *    and end at a small value between cpos+len and start of the next record.
1064 *    This fake record has r_refcount = 0.
1065 */
1066static int ocfs2_get_refcount_rec(struct ocfs2_caching_info *ci,
1067                                  struct buffer_head *ref_root_bh,
1068                                  u64 cpos, unsigned int len,
1069                                  struct ocfs2_refcount_rec *ret_rec,
1070                                  int *index,
1071                                  struct buffer_head **ret_bh)
1072{
1073        int ret = 0, i, found;
1074        u32 low_cpos, uninitialized_var(cpos_end);
1075        struct ocfs2_extent_list *el;
1076        struct ocfs2_extent_rec *rec = NULL;
1077        struct ocfs2_extent_block *eb = NULL;
1078        struct buffer_head *eb_bh = NULL, *ref_leaf_bh = NULL;
1079        struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
1080        struct ocfs2_refcount_block *rb =
1081                        (struct ocfs2_refcount_block *)ref_root_bh->b_data;
1082
1083        if (!(le32_to_cpu(rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL)) {
1084                ocfs2_find_refcount_rec_in_rl(ci, ref_root_bh, cpos, len,
1085                                              ret_rec, index);
1086                *ret_bh = ref_root_bh;
1087                get_bh(ref_root_bh);
1088                return 0;
1089        }
1090
1091        el = &rb->rf_list;
1092        low_cpos = cpos & OCFS2_32BIT_POS_MASK;
1093
1094        if (el->l_tree_depth) {
1095                ret = ocfs2_find_leaf(ci, el, low_cpos, &eb_bh);
1096                if (ret) {
1097                        mlog_errno(ret);
1098                        goto out;
1099                }
1100
1101                eb = (struct ocfs2_extent_block *) eb_bh->b_data;
1102                el = &eb->h_list;
1103
1104                if (el->l_tree_depth) {
1105                        ocfs2_error(sb,
1106                        "refcount tree %llu has non zero tree "
1107                        "depth in leaf btree tree block %llu\n",
1108                        (unsigned long long)ocfs2_metadata_cache_owner(ci),
1109                        (unsigned long long)eb_bh->b_blocknr);
1110                        ret = -EROFS;
1111                        goto out;
1112                }
1113        }
1114
1115        found = 0;
1116        for (i = le16_to_cpu(el->l_next_free_rec) - 1; i >= 0; i--) {
1117                rec = &el->l_recs[i];
1118
1119                if (le32_to_cpu(rec->e_cpos) <= low_cpos) {
1120                        found = 1;
1121                        break;
1122                }
1123        }
1124
1125        if (found) {
1126                ret = ocfs2_get_refcount_cpos_end(ci, ref_root_bh,
1127                                                  eb, el, i, &cpos_end);
1128                if (ret) {
1129                        mlog_errno(ret);
1130                        goto out;
1131                }
1132
1133                if (cpos_end < low_cpos + len)
1134                        len = cpos_end - low_cpos;
1135        }
1136
1137        ret = ocfs2_read_refcount_block(ci, le64_to_cpu(rec->e_blkno),
1138                                        &ref_leaf_bh);
1139        if (ret) {
1140                mlog_errno(ret);
1141                goto out;
1142        }
1143
1144        ocfs2_find_refcount_rec_in_rl(ci, ref_leaf_bh, cpos, len,
1145                                      ret_rec, index);
1146        *ret_bh = ref_leaf_bh;
1147out:
1148        brelse(eb_bh);
1149        return ret;
1150}
1151
1152enum ocfs2_ref_rec_contig {
1153        REF_CONTIG_NONE = 0,
1154        REF_CONTIG_LEFT,
1155        REF_CONTIG_RIGHT,
1156        REF_CONTIG_LEFTRIGHT,
1157};
1158
1159static enum ocfs2_ref_rec_contig
1160        ocfs2_refcount_rec_adjacent(struct ocfs2_refcount_block *rb,
1161                                    int index)
1162{
1163        if ((rb->rf_records.rl_recs[index].r_refcount ==
1164            rb->rf_records.rl_recs[index + 1].r_refcount) &&
1165            (le64_to_cpu(rb->rf_records.rl_recs[index].r_cpos) +
1166            le32_to_cpu(rb->rf_records.rl_recs[index].r_clusters) ==
1167            le64_to_cpu(rb->rf_records.rl_recs[index + 1].r_cpos)))
1168                return REF_CONTIG_RIGHT;
1169
1170        return REF_CONTIG_NONE;
1171}
1172
1173static enum ocfs2_ref_rec_contig
1174        ocfs2_refcount_rec_contig(struct ocfs2_refcount_block *rb,
1175                                  int index)
1176{
1177        enum ocfs2_ref_rec_contig ret = REF_CONTIG_NONE;
1178
1179        if (index < le16_to_cpu(rb->rf_records.rl_used) - 1)
1180                ret = ocfs2_refcount_rec_adjacent(rb, index);
1181
1182        if (index > 0) {
1183                enum ocfs2_ref_rec_contig tmp;
1184
1185                tmp = ocfs2_refcount_rec_adjacent(rb, index - 1);
1186
1187                if (tmp == REF_CONTIG_RIGHT) {
1188                        if (ret == REF_CONTIG_RIGHT)
1189                                ret = REF_CONTIG_LEFTRIGHT;
1190                        else
1191                                ret = REF_CONTIG_LEFT;
1192                }
1193        }
1194
1195        return ret;
1196}
1197
1198static void ocfs2_rotate_refcount_rec_left(struct ocfs2_refcount_block *rb,
1199                                           int index)
1200{
1201        BUG_ON(rb->rf_records.rl_recs[index].r_refcount !=
1202               rb->rf_records.rl_recs[index+1].r_refcount);
1203
1204        le32_add_cpu(&rb->rf_records.rl_recs[index].r_clusters,
1205                     le32_to_cpu(rb->rf_records.rl_recs[index+1].r_clusters));
1206
1207        if (index < le16_to_cpu(rb->rf_records.rl_used) - 2)
1208                memmove(&rb->rf_records.rl_recs[index + 1],
1209                        &rb->rf_records.rl_recs[index + 2],
1210                        sizeof(struct ocfs2_refcount_rec) *
1211                        (le16_to_cpu(rb->rf_records.rl_used) - index - 2));
1212
1213        memset(&rb->rf_records.rl_recs[le16_to_cpu(rb->rf_records.rl_used) - 1],
1214               0, sizeof(struct ocfs2_refcount_rec));
1215        le16_add_cpu(&rb->rf_records.rl_used, -1);
1216}
1217
1218/*
1219 * Merge the refcount rec if we are contiguous with the adjacent recs.
1220 */
1221static void ocfs2_refcount_rec_merge(struct ocfs2_refcount_block *rb,
1222                                     int index)
1223{
1224        enum ocfs2_ref_rec_contig contig =
1225                                ocfs2_refcount_rec_contig(rb, index);
1226
1227        if (contig == REF_CONTIG_NONE)
1228                return;
1229
1230        if (contig == REF_CONTIG_LEFT || contig == REF_CONTIG_LEFTRIGHT) {
1231                BUG_ON(index == 0);
1232                index--;
1233        }
1234
1235        ocfs2_rotate_refcount_rec_left(rb, index);
1236
1237        if (contig == REF_CONTIG_LEFTRIGHT)
1238                ocfs2_rotate_refcount_rec_left(rb, index);
1239}
1240
1241/*
1242 * Change the refcount indexed by "index" in ref_bh.
1243 * If refcount reaches 0, remove it.
1244 */
1245static int ocfs2_change_refcount_rec(handle_t *handle,
1246                                     struct ocfs2_caching_info *ci,
1247                                     struct buffer_head *ref_leaf_bh,
1248                                     int index, int merge, int change)
1249{
1250        int ret;
1251        struct ocfs2_refcount_block *rb =
1252                        (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
1253        struct ocfs2_refcount_list *rl = &rb->rf_records;
1254        struct ocfs2_refcount_rec *rec = &rl->rl_recs[index];
1255
1256        ret = ocfs2_journal_access_rb(handle, ci, ref_leaf_bh,
1257                                      OCFS2_JOURNAL_ACCESS_WRITE);
1258        if (ret) {
1259                mlog_errno(ret);
1260                goto out;
1261        }
1262
1263        trace_ocfs2_change_refcount_rec(
1264                (unsigned long long)ocfs2_metadata_cache_owner(ci),
1265                index, le32_to_cpu(rec->r_refcount), change);
1266        le32_add_cpu(&rec->r_refcount, change);
1267
1268        if (!rec->r_refcount) {
1269                if (index != le16_to_cpu(rl->rl_used) - 1) {
1270                        memmove(rec, rec + 1,
1271                                (le16_to_cpu(rl->rl_used) - index - 1) *
1272                                sizeof(struct ocfs2_refcount_rec));
1273                        memset(&rl->rl_recs[le16_to_cpu(rl->rl_used) - 1],
1274                               0, sizeof(struct ocfs2_refcount_rec));
1275                }
1276
1277                le16_add_cpu(&rl->rl_used, -1);
1278        } else if (merge)
1279                ocfs2_refcount_rec_merge(rb, index);
1280
1281        ocfs2_journal_dirty(handle, ref_leaf_bh);
1282out:
1283        return ret;
1284}
1285
1286static int ocfs2_expand_inline_ref_root(handle_t *handle,
1287                                        struct ocfs2_caching_info *ci,
1288                                        struct buffer_head *ref_root_bh,
1289                                        struct buffer_head **ref_leaf_bh,
1290                                        struct ocfs2_alloc_context *meta_ac)
1291{
1292        int ret;
1293        u16 suballoc_bit_start;
1294        u32 num_got;
1295        u64 suballoc_loc, blkno;
1296        struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
1297        struct buffer_head *new_bh = NULL;
1298        struct ocfs2_refcount_block *new_rb;
1299        struct ocfs2_refcount_block *root_rb =
1300                        (struct ocfs2_refcount_block *)ref_root_bh->b_data;
1301
1302        ret = ocfs2_journal_access_rb(handle, ci, ref_root_bh,
1303                                      OCFS2_JOURNAL_ACCESS_WRITE);
1304        if (ret) {
1305                mlog_errno(ret);
1306                goto out;
1307        }
1308
1309        ret = ocfs2_claim_metadata(handle, meta_ac, 1, &suballoc_loc,
1310                                   &suballoc_bit_start, &num_got,
1311                                   &blkno);
1312        if (ret) {
1313                mlog_errno(ret);
1314                goto out;
1315        }
1316
1317        new_bh = sb_getblk(sb, blkno);
1318        if (new_bh == NULL) {
1319                ret = -ENOMEM;
1320                mlog_errno(ret);
1321                goto out;
1322        }
1323        ocfs2_set_new_buffer_uptodate(ci, new_bh);
1324
1325        ret = ocfs2_journal_access_rb(handle, ci, new_bh,
1326                                      OCFS2_JOURNAL_ACCESS_CREATE);
1327        if (ret) {
1328                mlog_errno(ret);
1329                goto out;
1330        }
1331
1332        /*
1333         * Initialize ocfs2_refcount_block.
1334         * It should contain the same information as the old root.
1335         * so just memcpy it and change the corresponding field.
1336         */
1337        memcpy(new_bh->b_data, ref_root_bh->b_data, sb->s_blocksize);
1338
1339        new_rb = (struct ocfs2_refcount_block *)new_bh->b_data;
1340        new_rb->rf_suballoc_slot = cpu_to_le16(meta_ac->ac_alloc_slot);
1341        new_rb->rf_suballoc_loc = cpu_to_le64(suballoc_loc);
1342        new_rb->rf_suballoc_bit = cpu_to_le16(suballoc_bit_start);
1343        new_rb->rf_blkno = cpu_to_le64(blkno);
1344        new_rb->rf_cpos = cpu_to_le32(0);
1345        new_rb->rf_parent = cpu_to_le64(ref_root_bh->b_blocknr);
1346        new_rb->rf_flags = cpu_to_le32(OCFS2_REFCOUNT_LEAF_FL);
1347        ocfs2_journal_dirty(handle, new_bh);
1348
1349        /* Now change the root. */
1350        memset(&root_rb->rf_list, 0, sb->s_blocksize -
1351               offsetof(struct ocfs2_refcount_block, rf_list));
1352        root_rb->rf_list.l_count = cpu_to_le16(ocfs2_extent_recs_per_rb(sb));
1353        root_rb->rf_clusters = cpu_to_le32(1);
1354        root_rb->rf_list.l_next_free_rec = cpu_to_le16(1);
1355        root_rb->rf_list.l_recs[0].e_blkno = cpu_to_le64(blkno);
1356        root_rb->rf_list.l_recs[0].e_leaf_clusters = cpu_to_le16(1);
1357        root_rb->rf_flags = cpu_to_le32(OCFS2_REFCOUNT_TREE_FL);
1358
1359        ocfs2_journal_dirty(handle, ref_root_bh);
1360
1361        trace_ocfs2_expand_inline_ref_root((unsigned long long)blkno,
1362                le16_to_cpu(new_rb->rf_records.rl_used));
1363
1364        *ref_leaf_bh = new_bh;
1365        new_bh = NULL;
1366out:
1367        brelse(new_bh);
1368        return ret;
1369}
1370
1371static int ocfs2_refcount_rec_no_intersect(struct ocfs2_refcount_rec *prev,
1372                                           struct ocfs2_refcount_rec *next)
1373{
1374        if (ocfs2_get_ref_rec_low_cpos(prev) + le32_to_cpu(prev->r_clusters) <=
1375                ocfs2_get_ref_rec_low_cpos(next))
1376                return 1;
1377
1378        return 0;
1379}
1380
1381static int cmp_refcount_rec_by_low_cpos(const void *a, const void *b)
1382{
1383        const struct ocfs2_refcount_rec *l = a, *r = b;
1384        u32 l_cpos = ocfs2_get_ref_rec_low_cpos(l);
1385        u32 r_cpos = ocfs2_get_ref_rec_low_cpos(r);
1386
1387        if (l_cpos > r_cpos)
1388                return 1;
1389        if (l_cpos < r_cpos)
1390                return -1;
1391        return 0;
1392}
1393
1394static int cmp_refcount_rec_by_cpos(const void *a, const void *b)
1395{
1396        const struct ocfs2_refcount_rec *l = a, *r = b;
1397        u64 l_cpos = le64_to_cpu(l->r_cpos);
1398        u64 r_cpos = le64_to_cpu(r->r_cpos);
1399
1400        if (l_cpos > r_cpos)
1401                return 1;
1402        if (l_cpos < r_cpos)
1403                return -1;
1404        return 0;
1405}
1406
1407static void swap_refcount_rec(void *a, void *b, int size)
1408{
1409        struct ocfs2_refcount_rec *l = a, *r = b;
1410
1411        swap(*l, *r);
1412}
1413
1414/*
1415 * The refcount cpos are ordered by their 64bit cpos,
1416 * But we will use the low 32 bit to be the e_cpos in the b-tree.
1417 * So we need to make sure that this pos isn't intersected with others.
1418 *
1419 * Note: The refcount block is already sorted by their low 32 bit cpos,
1420 *       So just try the middle pos first, and we will exit when we find
1421 *       the good position.
1422 */
1423static int ocfs2_find_refcount_split_pos(struct ocfs2_refcount_list *rl,
1424                                         u32 *split_pos, int *split_index)
1425{
1426        int num_used = le16_to_cpu(rl->rl_used);
1427        int delta, middle = num_used / 2;
1428
1429        for (delta = 0; delta < middle; delta++) {
1430                /* Let's check delta earlier than middle */
1431                if (ocfs2_refcount_rec_no_intersect(
1432                                        &rl->rl_recs[middle - delta - 1],
1433                                        &rl->rl_recs[middle - delta])) {
1434                        *split_index = middle - delta;
1435                        break;
1436                }
1437
1438                /* For even counts, don't walk off the end */
1439                if ((middle + delta + 1) == num_used)
1440                        continue;
1441
1442                /* Now try delta past middle */
1443                if (ocfs2_refcount_rec_no_intersect(
1444                                        &rl->rl_recs[middle + delta],
1445                                        &rl->rl_recs[middle + delta + 1])) {
1446                        *split_index = middle + delta + 1;
1447                        break;
1448                }
1449        }
1450
1451        if (delta >= middle)
1452                return -ENOSPC;
1453
1454        *split_pos = ocfs2_get_ref_rec_low_cpos(&rl->rl_recs[*split_index]);
1455        return 0;
1456}
1457
1458static int ocfs2_divide_leaf_refcount_block(struct buffer_head *ref_leaf_bh,
1459                                            struct buffer_head *new_bh,
1460                                            u32 *split_cpos)
1461{
1462        int split_index = 0, num_moved, ret;
1463        u32 cpos = 0;
1464        struct ocfs2_refcount_block *rb =
1465                        (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
1466        struct ocfs2_refcount_list *rl = &rb->rf_records;
1467        struct ocfs2_refcount_block *new_rb =
1468                        (struct ocfs2_refcount_block *)new_bh->b_data;
1469        struct ocfs2_refcount_list *new_rl = &new_rb->rf_records;
1470
1471        trace_ocfs2_divide_leaf_refcount_block(
1472                (unsigned long long)ref_leaf_bh->b_blocknr,
1473                le16_to_cpu(rl->rl_count), le16_to_cpu(rl->rl_used));
1474
1475        /*
1476         * XXX: Improvement later.
1477         * If we know all the high 32 bit cpos is the same, no need to sort.
1478         *
1479         * In order to make the whole process safe, we do:
1480         * 1. sort the entries by their low 32 bit cpos first so that we can
1481         *    find the split cpos easily.
1482         * 2. call ocfs2_insert_extent to insert the new refcount block.
1483         * 3. move the refcount rec to the new block.
1484         * 4. sort the entries by their 64 bit cpos.
1485         * 5. dirty the new_rb and rb.
1486         */
1487        sort(&rl->rl_recs, le16_to_cpu(rl->rl_used),
1488             sizeof(struct ocfs2_refcount_rec),
1489             cmp_refcount_rec_by_low_cpos, swap_refcount_rec);
1490
1491        ret = ocfs2_find_refcount_split_pos(rl, &cpos, &split_index);
1492        if (ret) {
1493                mlog_errno(ret);
1494                return ret;
1495        }
1496
1497        new_rb->rf_cpos = cpu_to_le32(cpos);
1498
1499        /* move refcount records starting from split_index to the new block. */
1500        num_moved = le16_to_cpu(rl->rl_used) - split_index;
1501        memcpy(new_rl->rl_recs, &rl->rl_recs[split_index],
1502               num_moved * sizeof(struct ocfs2_refcount_rec));
1503
1504        /*ok, remove the entries we just moved over to the other block. */
1505        memset(&rl->rl_recs[split_index], 0,
1506               num_moved * sizeof(struct ocfs2_refcount_rec));
1507
1508        /* change old and new rl_used accordingly. */
1509        le16_add_cpu(&rl->rl_used, -num_moved);
1510        new_rl->rl_used = cpu_to_le16(num_moved);
1511
1512        sort(&rl->rl_recs, le16_to_cpu(rl->rl_used),
1513             sizeof(struct ocfs2_refcount_rec),
1514             cmp_refcount_rec_by_cpos, swap_refcount_rec);
1515
1516        sort(&new_rl->rl_recs, le16_to_cpu(new_rl->rl_used),
1517             sizeof(struct ocfs2_refcount_rec),
1518             cmp_refcount_rec_by_cpos, swap_refcount_rec);
1519
1520        *split_cpos = cpos;
1521        return 0;
1522}
1523
1524static int ocfs2_new_leaf_refcount_block(handle_t *handle,
1525                                         struct ocfs2_caching_info *ci,
1526                                         struct buffer_head *ref_root_bh,
1527                                         struct buffer_head *ref_leaf_bh,
1528                                         struct ocfs2_alloc_context *meta_ac)
1529{
1530        int ret;
1531        u16 suballoc_bit_start;
1532        u32 num_got, new_cpos;
1533        u64 suballoc_loc, blkno;
1534        struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
1535        struct ocfs2_refcount_block *root_rb =
1536                        (struct ocfs2_refcount_block *)ref_root_bh->b_data;
1537        struct buffer_head *new_bh = NULL;
1538        struct ocfs2_refcount_block *new_rb;
1539        struct ocfs2_extent_tree ref_et;
1540
1541        BUG_ON(!(le32_to_cpu(root_rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL));
1542
1543        ret = ocfs2_journal_access_rb(handle, ci, ref_root_bh,
1544                                      OCFS2_JOURNAL_ACCESS_WRITE);
1545        if (ret) {
1546                mlog_errno(ret);
1547                goto out;
1548        }
1549
1550        ret = ocfs2_journal_access_rb(handle, ci, ref_leaf_bh,
1551                                      OCFS2_JOURNAL_ACCESS_WRITE);
1552        if (ret) {
1553                mlog_errno(ret);
1554                goto out;
1555        }
1556
1557        ret = ocfs2_claim_metadata(handle, meta_ac, 1, &suballoc_loc,
1558                                   &suballoc_bit_start, &num_got,
1559                                   &blkno);
1560        if (ret) {
1561                mlog_errno(ret);
1562                goto out;
1563        }
1564
1565        new_bh = sb_getblk(sb, blkno);
1566        if (new_bh == NULL) {
1567                ret = -ENOMEM;
1568                mlog_errno(ret);
1569                goto out;
1570        }
1571        ocfs2_set_new_buffer_uptodate(ci, new_bh);
1572
1573        ret = ocfs2_journal_access_rb(handle, ci, new_bh,
1574                                      OCFS2_JOURNAL_ACCESS_CREATE);
1575        if (ret) {
1576                mlog_errno(ret);
1577                goto out;
1578        }
1579
1580        /* Initialize ocfs2_refcount_block. */
1581        new_rb = (struct ocfs2_refcount_block *)new_bh->b_data;
1582        memset(new_rb, 0, sb->s_blocksize);
1583        strcpy((void *)new_rb, OCFS2_REFCOUNT_BLOCK_SIGNATURE);
1584        new_rb->rf_suballoc_slot = cpu_to_le16(meta_ac->ac_alloc_slot);
1585        new_rb->rf_suballoc_loc = cpu_to_le64(suballoc_loc);
1586        new_rb->rf_suballoc_bit = cpu_to_le16(suballoc_bit_start);
1587        new_rb->rf_fs_generation = cpu_to_le32(OCFS2_SB(sb)->fs_generation);
1588        new_rb->rf_blkno = cpu_to_le64(blkno);
1589        new_rb->rf_parent = cpu_to_le64(ref_root_bh->b_blocknr);
1590        new_rb->rf_flags = cpu_to_le32(OCFS2_REFCOUNT_LEAF_FL);
1591        new_rb->rf_records.rl_count =
1592                                cpu_to_le16(ocfs2_refcount_recs_per_rb(sb));
1593        new_rb->rf_generation = root_rb->rf_generation;
1594
1595        ret = ocfs2_divide_leaf_refcount_block(ref_leaf_bh, new_bh, &new_cpos);
1596        if (ret) {
1597                mlog_errno(ret);
1598                goto out;
1599        }
1600
1601        ocfs2_journal_dirty(handle, ref_leaf_bh);
1602        ocfs2_journal_dirty(handle, new_bh);
1603
1604        ocfs2_init_refcount_extent_tree(&ref_et, ci, ref_root_bh);
1605
1606        trace_ocfs2_new_leaf_refcount_block(
1607                        (unsigned long long)new_bh->b_blocknr, new_cpos);
1608
1609        /* Insert the new leaf block with the specific offset cpos. */
1610        ret = ocfs2_insert_extent(handle, &ref_et, new_cpos, new_bh->b_blocknr,
1611                                  1, 0, meta_ac);
1612        if (ret)
1613                mlog_errno(ret);
1614
1615out:
1616        brelse(new_bh);
1617        return ret;
1618}
1619
1620static int ocfs2_expand_refcount_tree(handle_t *handle,
1621                                      struct ocfs2_caching_info *ci,
1622                                      struct buffer_head *ref_root_bh,
1623                                      struct buffer_head *ref_leaf_bh,
1624                                      struct ocfs2_alloc_context *meta_ac)
1625{
1626        int ret;
1627        struct buffer_head *expand_bh = NULL;
1628
1629        if (ref_root_bh == ref_leaf_bh) {
1630                /*
1631                 * the old root bh hasn't been expanded to a b-tree,
1632                 * so expand it first.
1633                 */
1634                ret = ocfs2_expand_inline_ref_root(handle, ci, ref_root_bh,
1635                                                   &expand_bh, meta_ac);
1636                if (ret) {
1637                        mlog_errno(ret);
1638                        goto out;
1639                }
1640        } else {
1641                expand_bh = ref_leaf_bh;
1642                get_bh(expand_bh);
1643        }
1644
1645
1646        /* Now add a new refcount block into the tree.*/
1647        ret = ocfs2_new_leaf_refcount_block(handle, ci, ref_root_bh,
1648                                            expand_bh, meta_ac);
1649        if (ret)
1650                mlog_errno(ret);
1651out:
1652        brelse(expand_bh);
1653        return ret;
1654}
1655
1656/*
1657 * Adjust the extent rec in b-tree representing ref_leaf_bh.
1658 *
1659 * Only called when we have inserted a new refcount rec at index 0
1660 * which means ocfs2_extent_rec.e_cpos may need some change.
1661 */
1662static int ocfs2_adjust_refcount_rec(handle_t *handle,
1663                                     struct ocfs2_caching_info *ci,
1664                                     struct buffer_head *ref_root_bh,
1665                                     struct buffer_head *ref_leaf_bh,
1666                                     struct ocfs2_refcount_rec *rec)
1667{
1668        int ret = 0, i;
1669        u32 new_cpos, old_cpos;
1670        struct ocfs2_path *path = NULL;
1671        struct ocfs2_extent_tree et;
1672        struct ocfs2_refcount_block *rb =
1673                (struct ocfs2_refcount_block *)ref_root_bh->b_data;
1674        struct ocfs2_extent_list *el;
1675
1676        if (!(le32_to_cpu(rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL))
1677                goto out;
1678
1679        rb = (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
1680        old_cpos = le32_to_cpu(rb->rf_cpos);
1681        new_cpos = le64_to_cpu(rec->r_cpos) & OCFS2_32BIT_POS_MASK;
1682        if (old_cpos <= new_cpos)
1683                goto out;
1684
1685        ocfs2_init_refcount_extent_tree(&et, ci, ref_root_bh);
1686
1687        path = ocfs2_new_path_from_et(&et);
1688        if (!path) {
1689                ret = -ENOMEM;
1690                mlog_errno(ret);
1691                goto out;
1692        }
1693
1694        ret = ocfs2_find_path(ci, path, old_cpos);
1695        if (ret) {
1696                mlog_errno(ret);
1697                goto out;
1698        }
1699
1700        /*
1701         * 2 more credits, one for the leaf refcount block, one for
1702         * the extent block contains the extent rec.
1703         */
1704        ret = ocfs2_extend_trans(handle, 2);
1705        if (ret < 0) {
1706                mlog_errno(ret);
1707                goto out;
1708        }
1709
1710        ret = ocfs2_journal_access_rb(handle, ci, ref_leaf_bh,
1711                                      OCFS2_JOURNAL_ACCESS_WRITE);
1712        if (ret < 0) {
1713                mlog_errno(ret);
1714                goto out;
1715        }
1716
1717        ret = ocfs2_journal_access_eb(handle, ci, path_leaf_bh(path),
1718                                      OCFS2_JOURNAL_ACCESS_WRITE);
1719        if (ret < 0) {
1720                mlog_errno(ret);
1721                goto out;
1722        }
1723
1724        /* change the leaf extent block first. */
1725        el = path_leaf_el(path);
1726
1727        for (i = 0; i < le16_to_cpu(el->l_next_free_rec); i++)
1728                if (le32_to_cpu(el->l_recs[i].e_cpos) == old_cpos)
1729                        break;
1730
1731        BUG_ON(i == le16_to_cpu(el->l_next_free_rec));
1732
1733        el->l_recs[i].e_cpos = cpu_to_le32(new_cpos);
1734
1735        /* change the r_cpos in the leaf block. */
1736        rb->rf_cpos = cpu_to_le32(new_cpos);
1737
1738        ocfs2_journal_dirty(handle, path_leaf_bh(path));
1739        ocfs2_journal_dirty(handle, ref_leaf_bh);
1740
1741out:
1742        ocfs2_free_path(path);
1743        return ret;
1744}
1745
1746static int ocfs2_insert_refcount_rec(handle_t *handle,
1747                                     struct ocfs2_caching_info *ci,
1748                                     struct buffer_head *ref_root_bh,
1749                                     struct buffer_head *ref_leaf_bh,
1750                                     struct ocfs2_refcount_rec *rec,
1751                                     int index, int merge,
1752                                     struct ocfs2_alloc_context *meta_ac)
1753{
1754        int ret;
1755        struct ocfs2_refcount_block *rb =
1756                        (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
1757        struct ocfs2_refcount_list *rf_list = &rb->rf_records;
1758        struct buffer_head *new_bh = NULL;
1759
1760        BUG_ON(le32_to_cpu(rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL);
1761
1762        if (rf_list->rl_used == rf_list->rl_count) {
1763                u64 cpos = le64_to_cpu(rec->r_cpos);
1764                u32 len = le32_to_cpu(rec->r_clusters);
1765
1766                ret = ocfs2_expand_refcount_tree(handle, ci, ref_root_bh,
1767                                                 ref_leaf_bh, meta_ac);
1768                if (ret) {
1769                        mlog_errno(ret);
1770                        goto out;
1771                }
1772
1773                ret = ocfs2_get_refcount_rec(ci, ref_root_bh,
1774                                             cpos, len, NULL, &index,
1775                                             &new_bh);
1776                if (ret) {
1777                        mlog_errno(ret);
1778                        goto out;
1779                }
1780
1781                ref_leaf_bh = new_bh;
1782                rb = (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
1783                rf_list = &rb->rf_records;
1784        }
1785
1786        ret = ocfs2_journal_access_rb(handle, ci, ref_leaf_bh,
1787                                      OCFS2_JOURNAL_ACCESS_WRITE);
1788        if (ret) {
1789                mlog_errno(ret);
1790                goto out;
1791        }
1792
1793        if (index < le16_to_cpu(rf_list->rl_used))
1794                memmove(&rf_list->rl_recs[index + 1],
1795                        &rf_list->rl_recs[index],
1796                        (le16_to_cpu(rf_list->rl_used) - index) *
1797                         sizeof(struct ocfs2_refcount_rec));
1798
1799        trace_ocfs2_insert_refcount_rec(
1800                (unsigned long long)ref_leaf_bh->b_blocknr, index,
1801                (unsigned long long)le64_to_cpu(rec->r_cpos),
1802                le32_to_cpu(rec->r_clusters), le32_to_cpu(rec->r_refcount));
1803
1804        rf_list->rl_recs[index] = *rec;
1805
1806        le16_add_cpu(&rf_list->rl_used, 1);
1807
1808        if (merge)
1809                ocfs2_refcount_rec_merge(rb, index);
1810
1811        ocfs2_journal_dirty(handle, ref_leaf_bh);
1812
1813        if (index == 0) {
1814                ret = ocfs2_adjust_refcount_rec(handle, ci,
1815                                                ref_root_bh,
1816                                                ref_leaf_bh, rec);
1817                if (ret)
1818                        mlog_errno(ret);
1819        }
1820out:
1821        brelse(new_bh);
1822        return ret;
1823}
1824
1825/*
1826 * Split the refcount_rec indexed by "index" in ref_leaf_bh.
1827 * This is much simple than our b-tree code.
1828 * split_rec is the new refcount rec we want to insert.
1829 * If split_rec->r_refcount > 0, we are changing the refcount(in case we
1830 * increase refcount or decrease a refcount to non-zero).
1831 * If split_rec->r_refcount == 0, we are punching a hole in current refcount
1832 * rec( in case we decrease a refcount to zero).
1833 */
1834static int ocfs2_split_refcount_rec(handle_t *handle,
1835                                    struct ocfs2_caching_info *ci,
1836                                    struct buffer_head *ref_root_bh,
1837                                    struct buffer_head *ref_leaf_bh,
1838                                    struct ocfs2_refcount_rec *split_rec,
1839                                    int index, int merge,
1840                                    struct ocfs2_alloc_context *meta_ac,
1841                                    struct ocfs2_cached_dealloc_ctxt *dealloc)
1842{
1843        int ret, recs_need;
1844        u32 len;
1845        struct ocfs2_refcount_block *rb =
1846                        (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
1847        struct ocfs2_refcount_list *rf_list = &rb->rf_records;
1848        struct ocfs2_refcount_rec *orig_rec = &rf_list->rl_recs[index];
1849        struct ocfs2_refcount_rec *tail_rec = NULL;
1850        struct buffer_head *new_bh = NULL;
1851
1852        BUG_ON(le32_to_cpu(rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL);
1853
1854        trace_ocfs2_split_refcount_rec(le64_to_cpu(orig_rec->r_cpos),
1855                le32_to_cpu(orig_rec->r_clusters),
1856                le32_to_cpu(orig_rec->r_refcount),
1857                le64_to_cpu(split_rec->r_cpos),
1858                le32_to_cpu(split_rec->r_clusters),
1859                le32_to_cpu(split_rec->r_refcount));
1860
1861        /*
1862         * If we just need to split the header or tail clusters,
1863         * no more recs are needed, just split is OK.
1864         * Otherwise we at least need one new recs.
1865         */
1866        if (!split_rec->r_refcount &&
1867            (split_rec->r_cpos == orig_rec->r_cpos ||
1868             le64_to_cpu(split_rec->r_cpos) +
1869             le32_to_cpu(split_rec->r_clusters) ==
1870             le64_to_cpu(orig_rec->r_cpos) + le32_to_cpu(orig_rec->r_clusters)))
1871                recs_need = 0;
1872        else
1873                recs_need = 1;
1874
1875        /*
1876         * We need one more rec if we split in the middle and the new rec have
1877         * some refcount in it.
1878         */
1879        if (split_rec->r_refcount &&
1880            (split_rec->r_cpos != orig_rec->r_cpos &&
1881             le64_to_cpu(split_rec->r_cpos) +
1882             le32_to_cpu(split_rec->r_clusters) !=
1883             le64_to_cpu(orig_rec->r_cpos) + le32_to_cpu(orig_rec->r_clusters)))
1884                recs_need++;
1885
1886        /* If the leaf block don't have enough record, expand it. */
1887        if (le16_to_cpu(rf_list->rl_used) + recs_need >
1888                                         le16_to_cpu(rf_list->rl_count)) {
1889                struct ocfs2_refcount_rec tmp_rec;
1890                u64 cpos = le64_to_cpu(orig_rec->r_cpos);
1891                len = le32_to_cpu(orig_rec->r_clusters);
1892                ret = ocfs2_expand_refcount_tree(handle, ci, ref_root_bh,
1893                                                 ref_leaf_bh, meta_ac);
1894                if (ret) {
1895                        mlog_errno(ret);
1896                        goto out;
1897                }
1898
1899                /*
1900                 * We have to re-get it since now cpos may be moved to
1901                 * another leaf block.
1902                 */
1903                ret = ocfs2_get_refcount_rec(ci, ref_root_bh,
1904                                             cpos, len, &tmp_rec, &index,
1905                                             &new_bh);
1906                if (ret) {
1907                        mlog_errno(ret);
1908                        goto out;
1909                }
1910
1911                ref_leaf_bh = new_bh;
1912                rb = (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
1913                rf_list = &rb->rf_records;
1914                orig_rec = &rf_list->rl_recs[index];
1915        }
1916
1917        ret = ocfs2_journal_access_rb(handle, ci, ref_leaf_bh,
1918                                      OCFS2_JOURNAL_ACCESS_WRITE);
1919        if (ret) {
1920                mlog_errno(ret);
1921                goto out;
1922        }
1923
1924        /*
1925         * We have calculated out how many new records we need and store
1926         * in recs_need, so spare enough space first by moving the records
1927         * after "index" to the end.
1928         */
1929        if (index != le16_to_cpu(rf_list->rl_used) - 1)
1930                memmove(&rf_list->rl_recs[index + 1 + recs_need],
1931                        &rf_list->rl_recs[index + 1],
1932                        (le16_to_cpu(rf_list->rl_used) - index - 1) *
1933                         sizeof(struct ocfs2_refcount_rec));
1934
1935        len = (le64_to_cpu(orig_rec->r_cpos) +
1936              le32_to_cpu(orig_rec->r_clusters)) -
1937              (le64_to_cpu(split_rec->r_cpos) +
1938              le32_to_cpu(split_rec->r_clusters));
1939
1940        /*
1941         * If we have "len", the we will split in the tail and move it
1942         * to the end of the space we have just spared.
1943         */
1944        if (len) {
1945                tail_rec = &rf_list->rl_recs[index + recs_need];
1946
1947                memcpy(tail_rec, orig_rec, sizeof(struct ocfs2_refcount_rec));
1948                le64_add_cpu(&tail_rec->r_cpos,
1949                             le32_to_cpu(tail_rec->r_clusters) - len);
1950                tail_rec->r_clusters = cpu_to_le32(len);
1951        }
1952
1953        /*
1954         * If the split pos isn't the same as the original one, we need to
1955         * split in the head.
1956         *
1957         * Note: We have the chance that split_rec.r_refcount = 0,
1958         * recs_need = 0 and len > 0, which means we just cut the head from
1959         * the orig_rec and in that case we have done some modification in
1960         * orig_rec above, so the check for r_cpos is faked.
1961         */
1962        if (split_rec->r_cpos != orig_rec->r_cpos && tail_rec != orig_rec) {
1963                len = le64_to_cpu(split_rec->r_cpos) -
1964                      le64_to_cpu(orig_rec->r_cpos);
1965                orig_rec->r_clusters = cpu_to_le32(len);
1966                index++;
1967        }
1968
1969        le16_add_cpu(&rf_list->rl_used, recs_need);
1970
1971        if (split_rec->r_refcount) {
1972                rf_list->rl_recs[index] = *split_rec;
1973                trace_ocfs2_split_refcount_rec_insert(
1974                        (unsigned long long)ref_leaf_bh->b_blocknr, index,
1975                        (unsigned long long)le64_to_cpu(split_rec->r_cpos),
1976                        le32_to_cpu(split_rec->r_clusters),
1977                        le32_to_cpu(split_rec->r_refcount));
1978
1979                if (merge)
1980                        ocfs2_refcount_rec_merge(rb, index);
1981        }
1982
1983        ocfs2_journal_dirty(handle, ref_leaf_bh);
1984
1985out:
1986        brelse(new_bh);
1987        return ret;
1988}
1989
1990static int __ocfs2_increase_refcount(handle_t *handle,
1991                                     struct ocfs2_caching_info *ci,
1992                                     struct buffer_head *ref_root_bh,
1993                                     u64 cpos, u32 len, int merge,
1994                                     struct ocfs2_alloc_context *meta_ac,
1995                                     struct ocfs2_cached_dealloc_ctxt *dealloc)
1996{
1997        int ret = 0, index;
1998        struct buffer_head *ref_leaf_bh = NULL;
1999        struct ocfs2_refcount_rec rec;
2000        unsigned int set_len = 0;
2001
2002        trace_ocfs2_increase_refcount_begin(
2003             (unsigned long long)ocfs2_metadata_cache_owner(ci),
2004             (unsigned long long)cpos, len);
2005
2006        while (len) {
2007                ret = ocfs2_get_refcount_rec(ci, ref_root_bh,
2008                                             cpos, len, &rec, &index,
2009                                             &ref_leaf_bh);
2010                if (ret) {
2011                        mlog_errno(ret);
2012                        goto out;
2013                }
2014
2015                set_len = le32_to_cpu(rec.r_clusters);
2016
2017                /*
2018                 * Here we may meet with 3 situations:
2019                 *
2020                 * 1. If we find an already existing record, and the length
2021                 *    is the same, cool, we just need to increase the r_refcount
2022                 *    and it is OK.
2023                 * 2. If we find a hole, just insert it with r_refcount = 1.
2024                 * 3. If we are in the middle of one extent record, split
2025                 *    it.
2026                 */
2027                if (rec.r_refcount && le64_to_cpu(rec.r_cpos) == cpos &&
2028                    set_len <= len) {
2029                        trace_ocfs2_increase_refcount_change(
2030                                (unsigned long long)cpos, set_len,
2031                                le32_to_cpu(rec.r_refcount));
2032                        ret = ocfs2_change_refcount_rec(handle, ci,
2033                                                        ref_leaf_bh, index,
2034                                                        merge, 1);
2035                        if (ret) {
2036                                mlog_errno(ret);
2037                                goto out;
2038                        }
2039                } else if (!rec.r_refcount) {
2040                        rec.r_refcount = cpu_to_le32(1);
2041
2042                        trace_ocfs2_increase_refcount_insert(
2043                             (unsigned long long)le64_to_cpu(rec.r_cpos),
2044                             set_len);
2045                        ret = ocfs2_insert_refcount_rec(handle, ci, ref_root_bh,
2046                                                        ref_leaf_bh,
2047                                                        &rec, index,
2048                                                        merge, meta_ac);
2049                        if (ret) {
2050                                mlog_errno(ret);
2051                                goto out;
2052                        }
2053                } else  {
2054                        set_len = min((u64)(cpos + len),
2055                                      le64_to_cpu(rec.r_cpos) + set_len) - cpos;
2056                        rec.r_cpos = cpu_to_le64(cpos);
2057                        rec.r_clusters = cpu_to_le32(set_len);
2058                        le32_add_cpu(&rec.r_refcount, 1);
2059
2060                        trace_ocfs2_increase_refcount_split(
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
2079out:
2080        brelse(ref_leaf_bh);
2081        return ret;
2082}
2083
2084static 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        trace_ocfs2_remove_refcount_extent(
2100                (unsigned long long)ocfs2_metadata_cache_owner(ci),
2101                (unsigned long long)ref_leaf_bh->b_blocknr,
2102                le32_to_cpu(rb->rf_cpos));
2103
2104        ocfs2_init_refcount_extent_tree(&et, ci, ref_root_bh);
2105        ret = ocfs2_remove_extent(handle, &et, le32_to_cpu(rb->rf_cpos),
2106                                  1, meta_ac, dealloc);
2107        if (ret) {
2108                mlog_errno(ret);
2109                goto out;
2110        }
2111
2112        ocfs2_remove_from_cache(ci, ref_leaf_bh);
2113
2114        /*
2115         * add the freed block to the dealloc so that it will be freed
2116         * when we run dealloc.
2117         */
2118        ret = ocfs2_cache_block_dealloc(dealloc, EXTENT_ALLOC_SYSTEM_INODE,
2119                                        le16_to_cpu(rb->rf_suballoc_slot),
2120                                        le64_to_cpu(rb->rf_suballoc_loc),
2121                                        le64_to_cpu(rb->rf_blkno),
2122                                        le16_to_cpu(rb->rf_suballoc_bit));
2123        if (ret) {
2124                mlog_errno(ret);
2125                goto out;
2126        }
2127
2128        ret = ocfs2_journal_access_rb(handle, ci, ref_root_bh,
2129                                      OCFS2_JOURNAL_ACCESS_WRITE);
2130        if (ret) {
2131                mlog_errno(ret);
2132                goto out;
2133        }
2134
2135        rb = (struct ocfs2_refcount_block *)ref_root_bh->b_data;
2136
2137        le32_add_cpu(&rb->rf_clusters, -1);
2138
2139        /*
2140         * check whether we need to restore the root refcount block if
2141         * there is no leaf extent block at atll.
2142         */
2143        if (!rb->rf_list.l_next_free_rec) {
2144                BUG_ON(rb->rf_clusters);
2145
2146                trace_ocfs2_restore_refcount_block(
2147                     (unsigned long long)ref_root_bh->b_blocknr);
2148
2149                rb->rf_flags = 0;
2150                rb->rf_parent = 0;
2151                rb->rf_cpos = 0;
2152                memset(&rb->rf_records, 0, sb->s_blocksize -
2153                       offsetof(struct ocfs2_refcount_block, rf_records));
2154                rb->rf_records.rl_count =
2155                                cpu_to_le16(ocfs2_refcount_recs_per_rb(sb));
2156        }
2157
2158        ocfs2_journal_dirty(handle, ref_root_bh);
2159
2160out:
2161        return ret;
2162}
2163
2164int ocfs2_increase_refcount(handle_t *handle,
2165                            struct ocfs2_caching_info *ci,
2166                            struct buffer_head *ref_root_bh,
2167                            u64 cpos, u32 len,
2168                            struct ocfs2_alloc_context *meta_ac,
2169                            struct ocfs2_cached_dealloc_ctxt *dealloc)
2170{
2171        return __ocfs2_increase_refcount(handle, ci, ref_root_bh,
2172                                         cpos, len, 1,
2173                                         meta_ac, dealloc);
2174}
2175
2176static int ocfs2_decrease_refcount_rec(handle_t *handle,
2177                                struct ocfs2_caching_info *ci,
2178                                struct buffer_head *ref_root_bh,
2179                                struct buffer_head *ref_leaf_bh,
2180                                int index, u64 cpos, unsigned int len,
2181                                struct ocfs2_alloc_context *meta_ac,
2182                                struct ocfs2_cached_dealloc_ctxt *dealloc)
2183{
2184        int ret;
2185        struct ocfs2_refcount_block *rb =
2186                        (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
2187        struct ocfs2_refcount_rec *rec = &rb->rf_records.rl_recs[index];
2188
2189        BUG_ON(cpos < le64_to_cpu(rec->r_cpos));
2190        BUG_ON(cpos + len >
2191               le64_to_cpu(rec->r_cpos) + le32_to_cpu(rec->r_clusters));
2192
2193        trace_ocfs2_decrease_refcount_rec(
2194                (unsigned long long)ocfs2_metadata_cache_owner(ci),
2195                (unsigned long long)cpos, len);
2196
2197        if (cpos == le64_to_cpu(rec->r_cpos) &&
2198            len == le32_to_cpu(rec->r_clusters))
2199                ret = ocfs2_change_refcount_rec(handle, ci,
2200                                                ref_leaf_bh, index, 1, -1);
2201        else {
2202                struct ocfs2_refcount_rec split = *rec;
2203                split.r_cpos = cpu_to_le64(cpos);
2204                split.r_clusters = cpu_to_le32(len);
2205
2206                le32_add_cpu(&split.r_refcount, -1);
2207
2208                ret = ocfs2_split_refcount_rec(handle, ci,
2209                                               ref_root_bh, ref_leaf_bh,
2210                                               &split, index, 1,
2211                                               meta_ac, dealloc);
2212        }
2213
2214        if (ret) {
2215                mlog_errno(ret);
2216                goto out;
2217        }
2218
2219        /* Remove the leaf refcount block if it contains no refcount record. */
2220        if (!rb->rf_records.rl_used && ref_leaf_bh != ref_root_bh) {
2221                ret = ocfs2_remove_refcount_extent(handle, ci, ref_root_bh,
2222                                                   ref_leaf_bh, meta_ac,
2223                                                   dealloc);
2224                if (ret)
2225                        mlog_errno(ret);
2226        }
2227
2228out:
2229        return ret;
2230}
2231
2232static int __ocfs2_decrease_refcount(handle_t *handle,
2233                                     struct ocfs2_caching_info *ci,
2234                                     struct buffer_head *ref_root_bh,
2235                                     u64 cpos, u32 len,
2236                                     struct ocfs2_alloc_context *meta_ac,
2237                                     struct ocfs2_cached_dealloc_ctxt *dealloc,
2238                                     int delete)
2239{
2240        int ret = 0, index = 0;
2241        struct ocfs2_refcount_rec rec;
2242        unsigned int r_count = 0, r_len;
2243        struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
2244        struct buffer_head *ref_leaf_bh = NULL;
2245
2246        trace_ocfs2_decrease_refcount(
2247                (unsigned long long)ocfs2_metadata_cache_owner(ci),
2248                (unsigned long long)cpos, len, delete);
2249
2250        while (len) {
2251                ret = ocfs2_get_refcount_rec(ci, ref_root_bh,
2252                                             cpos, len, &rec, &index,
2253                                             &ref_leaf_bh);
2254                if (ret) {
2255                        mlog_errno(ret);
2256                        goto out;
2257                }
2258
2259                r_count = le32_to_cpu(rec.r_refcount);
2260                BUG_ON(r_count == 0);
2261                if (!delete)
2262                        BUG_ON(r_count > 1);
2263
2264                r_len = min((u64)(cpos + len), le64_to_cpu(rec.r_cpos) +
2265                              le32_to_cpu(rec.r_clusters)) - cpos;
2266
2267                ret = ocfs2_decrease_refcount_rec(handle, ci, ref_root_bh,
2268                                                  ref_leaf_bh, index,
2269                                                  cpos, r_len,
2270                                                  meta_ac, dealloc);
2271                if (ret) {
2272                        mlog_errno(ret);
2273                        goto out;
2274                }
2275
2276                if (le32_to_cpu(rec.r_refcount) == 1 && delete) {
2277                        ret = ocfs2_cache_cluster_dealloc(dealloc,
2278                                          ocfs2_clusters_to_blocks(sb, cpos),
2279                                                          r_len);
2280                        if (ret) {
2281                                mlog_errno(ret);
2282                                goto out;
2283                        }
2284                }
2285
2286                cpos += r_len;
2287                len -= r_len;
2288                brelse(ref_leaf_bh);
2289                ref_leaf_bh = NULL;
2290        }
2291
2292out:
2293        brelse(ref_leaf_bh);
2294        return ret;
2295}
2296
2297/* Caller must hold refcount tree lock. */
2298int ocfs2_decrease_refcount(struct inode *inode,
2299                            handle_t *handle, u32 cpos, u32 len,
2300                            struct ocfs2_alloc_context *meta_ac,
2301                            struct ocfs2_cached_dealloc_ctxt *dealloc,
2302                            int delete)
2303{
2304        int ret;
2305        u64 ref_blkno;
2306        struct ocfs2_inode_info *oi = OCFS2_I(inode);
2307        struct buffer_head *ref_root_bh = NULL;
2308        struct ocfs2_refcount_tree *tree;
2309
2310        BUG_ON(!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL));
2311
2312        ret = ocfs2_get_refcount_block(inode, &ref_blkno);
2313        if (ret) {
2314                mlog_errno(ret);
2315                goto out;
2316        }
2317
2318        ret = ocfs2_get_refcount_tree(OCFS2_SB(inode->i_sb), ref_blkno, &tree);
2319        if (ret) {
2320                mlog_errno(ret);
2321                goto out;
2322        }
2323
2324        ret = ocfs2_read_refcount_block(&tree->rf_ci, tree->rf_blkno,
2325                                        &ref_root_bh);
2326        if (ret) {
2327                mlog_errno(ret);
2328                goto out;
2329        }
2330
2331        ret = __ocfs2_decrease_refcount(handle, &tree->rf_ci, ref_root_bh,
2332                                        cpos, len, meta_ac, dealloc, delete);
2333        if (ret)
2334                mlog_errno(ret);
2335out:
2336        brelse(ref_root_bh);
2337        return ret;
2338}
2339
2340/*
2341 * Mark the already-existing extent at cpos as refcounted for len clusters.
2342 * This adds the refcount extent flag.
2343 *
2344 * If the existing extent is larger than the request, initiate a
2345 * split. An attempt will be made at merging with adjacent extents.
2346 *
2347 * The caller is responsible for passing down meta_ac if we'll need it.
2348 */
2349static int ocfs2_mark_extent_refcounted(struct inode *inode,
2350                                struct ocfs2_extent_tree *et,
2351                                handle_t *handle, u32 cpos,
2352                                u32 len, u32 phys,
2353                                struct ocfs2_alloc_context *meta_ac,
2354                                struct ocfs2_cached_dealloc_ctxt *dealloc)
2355{
2356        int ret;
2357
2358        trace_ocfs2_mark_extent_refcounted(OCFS2_I(inode)->ip_blkno,
2359                                           cpos, len, phys);
2360
2361        if (!ocfs2_refcount_tree(OCFS2_SB(inode->i_sb))) {
2362                ocfs2_error(inode->i_sb, "Inode %lu want to use refcount "
2363                            "tree, but the feature bit is not set in the "
2364                            "super block.", inode->i_ino);
2365                ret = -EROFS;
2366                goto out;
2367        }
2368
2369        ret = ocfs2_change_extent_flag(handle, et, cpos,
2370                                       len, phys, meta_ac, dealloc,
2371                                       OCFS2_EXT_REFCOUNTED, 0);
2372        if (ret)
2373                mlog_errno(ret);
2374
2375out:
2376        return ret;
2377}
2378
2379/*
2380 * Given some contiguous physical clusters, calculate what we need
2381 * for modifying their refcount.
2382 */
2383static int ocfs2_calc_refcount_meta_credits(struct super_block *sb,
2384                                            struct ocfs2_caching_info *ci,
2385                                            struct buffer_head *ref_root_bh,
2386                                            u64 start_cpos,
2387                                            u32 clusters,
2388                                            int *meta_add,
2389                                            int *credits)
2390{
2391        int ret = 0, index, ref_blocks = 0, recs_add = 0;
2392        u64 cpos = start_cpos;
2393        struct ocfs2_refcount_block *rb;
2394        struct ocfs2_refcount_rec rec;
2395        struct buffer_head *ref_leaf_bh = NULL, *prev_bh = NULL;
2396        u32 len;
2397
2398        while (clusters) {
2399                ret = ocfs2_get_refcount_rec(ci, ref_root_bh,
2400                                             cpos, clusters, &rec,
2401                                             &index, &ref_leaf_bh);
2402                if (ret) {
2403                        mlog_errno(ret);
2404                        goto out;
2405                }
2406
2407                if (ref_leaf_bh != prev_bh) {
2408                        /*
2409                         * Now we encounter a new leaf block, so calculate
2410                         * whether we need to extend the old leaf.
2411                         */
2412                        if (prev_bh) {
2413                                rb = (struct ocfs2_refcount_block *)
2414                                                        prev_bh->b_data;
2415
2416                                if (le16_to_cpu(rb->rf_records.rl_used) +
2417                                    recs_add >
2418                                    le16_to_cpu(rb->rf_records.rl_count))
2419                                        ref_blocks++;
2420                        }
2421
2422                        recs_add = 0;
2423                        *credits += 1;
2424                        brelse(prev_bh);
2425                        prev_bh = ref_leaf_bh;
2426                        get_bh(prev_bh);
2427                }
2428
2429                trace_ocfs2_calc_refcount_meta_credits_iterate(
2430                                recs_add, (unsigned long long)cpos, clusters,
2431                                (unsigned long long)le64_to_cpu(rec.r_cpos),
2432                                le32_to_cpu(rec.r_clusters),
2433                                le32_to_cpu(rec.r_refcount), index);
2434
2435                len = min((u64)cpos + clusters, le64_to_cpu(rec.r_cpos) +
2436                          le32_to_cpu(rec.r_clusters)) - cpos;
2437                /*
2438                 * We record all the records which will be inserted to the
2439                 * same refcount block, so that we can tell exactly whether
2440                 * we need a new refcount block or not.
2441                 *
2442                 * If we will insert a new one, this is easy and only happens
2443                 * during adding refcounted flag to the extent, so we don't
2444                 * have a chance of spliting. We just need one record.
2445                 *
2446                 * If the refcount rec already exists, that would be a little
2447                 * complicated. we may have to:
2448                 * 1) split at the beginning if the start pos isn't aligned.
2449                 *    we need 1 more record in this case.
2450                 * 2) split int the end if the end pos isn't aligned.
2451                 *    we need 1 more record in this case.
2452                 * 3) split in the middle because of file system fragmentation.
2453                 *    we need 2 more records in this case(we can't detect this
2454                 *    beforehand, so always think of the worst case).
2455                 */
2456                if (rec.r_refcount) {
2457                        recs_add += 2;
2458                        /* Check whether we need a split at the beginning. */
2459                        if (cpos == start_cpos &&
2460                            cpos != le64_to_cpu(rec.r_cpos))
2461                                recs_add++;
2462
2463                        /* Check whether we need a split in the end. */
2464                        if (cpos + clusters < le64_to_cpu(rec.r_cpos) +
2465                            le32_to_cpu(rec.r_clusters))
2466                                recs_add++;
2467                } else
2468                        recs_add++;
2469
2470                brelse(ref_leaf_bh);
2471                ref_leaf_bh = NULL;
2472                clusters -= len;
2473                cpos += len;
2474        }
2475
2476        if (prev_bh) {
2477                rb = (struct ocfs2_refcount_block *)prev_bh->b_data;
2478
2479                if (le16_to_cpu(rb->rf_records.rl_used) + recs_add >
2480                    le16_to_cpu(rb->rf_records.rl_count))
2481                        ref_blocks++;
2482
2483                *credits += 1;
2484        }
2485
2486        if (!ref_blocks)
2487                goto out;
2488
2489        *meta_add += ref_blocks;
2490        *credits += ref_blocks;
2491
2492        /*
2493         * So we may need ref_blocks to insert into the tree.
2494         * That also means we need to change the b-tree and add that number
2495         * of records since we never merge them.
2496         * We need one more block for expansion since the new created leaf
2497         * block is also full and needs split.
2498         */
2499        rb = (struct ocfs2_refcount_block *)ref_root_bh->b_data;
2500        if (le32_to_cpu(rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL) {
2501                struct ocfs2_extent_tree et;
2502
2503                ocfs2_init_refcount_extent_tree(&et, ci, ref_root_bh);
2504                *meta_add += ocfs2_extend_meta_needed(et.et_root_el);
2505                *credits += ocfs2_calc_extend_credits(sb,
2506                                                      et.et_root_el);
2507        } else {
2508                *credits += OCFS2_EXPAND_REFCOUNT_TREE_CREDITS;
2509                *meta_add += 1;
2510        }
2511
2512out:
2513
2514        trace_ocfs2_calc_refcount_meta_credits(
2515                (unsigned long long)start_cpos, clusters,
2516                *meta_add, *credits);
2517        brelse(ref_leaf_bh);
2518        brelse(prev_bh);
2519        return ret;
2520}
2521
2522/*
2523 * For refcount tree, we will decrease some contiguous clusters
2524 * refcount count, so just go through it to see how many blocks
2525 * we gonna touch and whether we need to create new blocks.
2526 *
2527 * Normally the refcount blocks store these refcount should be
2528 * contiguous also, so that we can get the number easily.
2529 * We will at most add split 2 refcount records and 2 more
2530 * refcount blocks, so just check it in a rough way.
2531 *
2532 * Caller must hold refcount tree lock.
2533 */
2534int ocfs2_prepare_refcount_change_for_del(struct inode *inode,
2535                                          u64 refcount_loc,
2536                                          u64 phys_blkno,
2537                                          u32 clusters,
2538                                          int *credits,
2539                                          int *ref_blocks)
2540{
2541        int ret;
2542        struct ocfs2_inode_info *oi = OCFS2_I(inode);
2543        struct buffer_head *ref_root_bh = NULL;
2544        struct ocfs2_refcount_tree *tree;
2545        u64 start_cpos = ocfs2_blocks_to_clusters(inode->i_sb, phys_blkno);
2546
2547        if (!ocfs2_refcount_tree(OCFS2_SB(inode->i_sb))) {
2548                ocfs2_error(inode->i_sb, "Inode %lu want to use refcount "
2549                            "tree, but the feature bit is not set in the "
2550                            "super block.", inode->i_ino);
2551                ret = -EROFS;
2552                goto out;
2553        }
2554
2555        BUG_ON(!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL));
2556
2557        ret = ocfs2_get_refcount_tree(OCFS2_SB(inode->i_sb),
2558                                      refcount_loc, &tree);
2559        if (ret) {
2560                mlog_errno(ret);
2561                goto out;
2562        }
2563
2564        ret = ocfs2_read_refcount_block(&tree->rf_ci, refcount_loc,
2565                                        &ref_root_bh);
2566        if (ret) {
2567                mlog_errno(ret);
2568                goto out;
2569        }
2570
2571        ret = ocfs2_calc_refcount_meta_credits(inode->i_sb,
2572                                               &tree->rf_ci,
2573                                               ref_root_bh,
2574                                               start_cpos, clusters,
2575                                               ref_blocks, credits);
2576        if (ret) {
2577                mlog_errno(ret);
2578                goto out;
2579        }
2580
2581        trace_ocfs2_prepare_refcount_change_for_del(*ref_blocks, *credits);
2582
2583out:
2584        brelse(ref_root_bh);
2585        return ret;
2586}
2587
2588#define MAX_CONTIG_BYTES        1048576
2589
2590static inline unsigned int ocfs2_cow_contig_clusters(struct super_block *sb)
2591{
2592        return ocfs2_clusters_for_bytes(sb, MAX_CONTIG_BYTES);
2593}
2594
2595static 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 */
2607static 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 */
2620static 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 */
2645static 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
2839out:
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 */
2855static 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
2879        ret = ocfs2_calc_refcount_meta_credits(sb, ref_ci, ref_root_bh,
2880                                               p_cluster, num_clusters,
2881                                               &meta_add, credits);
2882        if (ret) {
2883                mlog_errno(ret);
2884                goto out;
2885        }
2886
2887        trace_ocfs2_lock_refcount_allocators(meta_add, *credits);
2888        ret = ocfs2_reserve_new_metadata_blocks(OCFS2_SB(sb), meta_add,
2889                                                meta_ac);
2890        if (ret) {
2891                mlog_errno(ret);
2892                goto out;
2893        }
2894
2895        if (data_ac) {
2896                ret = ocfs2_reserve_clusters(OCFS2_SB(sb), num_clusters,
2897                                             data_ac);
2898                if (ret)
2899                        mlog_errno(ret);
2900        }
2901
2902out:
2903        if (ret) {
2904                if (*meta_ac) {
2905                        ocfs2_free_alloc_context(*meta_ac);
2906                        *meta_ac = NULL;
2907                }
2908        }
2909
2910        return ret;
2911}
2912
2913static int ocfs2_clear_cow_buffer(handle_t *handle, struct buffer_head *bh)
2914{
2915        BUG_ON(buffer_dirty(bh));
2916
2917        clear_buffer_mapped(bh);
2918
2919        return 0;
2920}
2921
2922int ocfs2_duplicate_clusters_by_page(handle_t *handle,
2923                                     struct inode *inode,
2924                                     u32 cpos, u32 old_cluster,
2925                                     u32 new_cluster, u32 new_len)
2926{
2927        int ret = 0, partial;
2928        struct super_block *sb = inode->i_sb;
2929        u64 new_block = ocfs2_clusters_to_blocks(sb, new_cluster);
2930        struct page *page;
2931        pgoff_t page_index;
2932        unsigned int from, to, readahead_pages;
2933        loff_t offset, end, map_end;
2934        struct address_space *mapping = inode->i_mapping;
2935
2936        trace_ocfs2_duplicate_clusters_by_page(cpos, old_cluster,
2937                                               new_cluster, new_len);
2938
2939        readahead_pages =
2940                (ocfs2_cow_contig_clusters(sb) <<
2941                 OCFS2_SB(sb)->s_clustersize_bits) >> PAGE_CACHE_SHIFT;
2942        offset = ((loff_t)cpos) << OCFS2_SB(sb)->s_clustersize_bits;
2943        end = offset + (new_len << OCFS2_SB(sb)->s_clustersize_bits);
2944        /*
2945         * We only duplicate pages until we reach the page contains i_size - 1.
2946         * So trim 'end' to i_size.
2947         */
2948        if (end > i_size_read(inode))
2949                end = i_size_read(inode);
2950
2951        while (offset < end) {
2952                page_index = offset >> PAGE_CACHE_SHIFT;
2953                map_end = ((loff_t)page_index + 1) << PAGE_CACHE_SHIFT;
2954                if (map_end > end)
2955                        map_end = end;
2956
2957                /* from, to is the offset within the page. */
2958                from = offset & (PAGE_CACHE_SIZE - 1);
2959                to = PAGE_CACHE_SIZE;
2960                if (map_end & (PAGE_CACHE_SIZE - 1))
2961                        to = map_end & (PAGE_CACHE_SIZE - 1);
2962
2963                page = find_or_create_page(mapping, page_index, GFP_NOFS);
2964                if (!page) {
2965                        ret = -ENOMEM;
2966                        mlog_errno(ret);
2967                        break;
2968                }
2969
2970                /*
2971                 * In case PAGE_CACHE_SIZE <= CLUSTER_SIZE, This page
2972                 * can't be dirtied before we CoW it out.
2973                 */
2974                if (PAGE_CACHE_SIZE <= OCFS2_SB(sb)->s_clustersize)
2975                        BUG_ON(PageDirty(page));
2976
2977                if (!PageUptodate(page)) {
2978                        ret = block_read_full_page(page, ocfs2_get_block);
2979                        if (ret) {
2980                                mlog_errno(ret);
2981                                goto unlock;
2982                        }
2983                        lock_page(page);
2984                }
2985
2986                if (page_has_buffers(page)) {
2987                        ret = walk_page_buffers(handle, page_buffers(page),
2988                                                from, to, &partial,
2989                                                ocfs2_clear_cow_buffer);
2990                        if (ret) {
2991                                mlog_errno(ret);
2992                                goto unlock;
2993                        }
2994                }
2995
2996                ocfs2_map_and_dirty_page(inode,
2997                                         handle, from, to,
2998                                         page, 0, &new_block);
2999                mark_page_accessed(page);
3000unlock:
3001                unlock_page(page);
3002                page_cache_release(page);
3003                page = NULL;
3004                offset = map_end;
3005                if (ret)
3006                        break;
3007        }
3008
3009        return ret;
3010}
3011
3012int ocfs2_duplicate_clusters_by_jbd(handle_t *handle,
3013                                    struct inode *inode,
3014                                    u32 cpos, u32 old_cluster,
3015                                    u32 new_cluster, u32 new_len)
3016{
3017        int ret = 0;
3018        struct super_block *sb = inode->i_sb;
3019        struct ocfs2_caching_info *ci = INODE_CACHE(inode);
3020        int i, blocks = ocfs2_clusters_to_blocks(sb, new_len);
3021        u64 old_block = ocfs2_clusters_to_blocks(sb, old_cluster);
3022        u64 new_block = ocfs2_clusters_to_blocks(sb, new_cluster);
3023        struct ocfs2_super *osb = OCFS2_SB(sb);
3024        struct buffer_head *old_bh = NULL;
3025        struct buffer_head *new_bh = NULL;
3026
3027        trace_ocfs2_duplicate_clusters_by_page(cpos, old_cluster,
3028                                               new_cluster, new_len);
3029
3030        for (i = 0; i < blocks; i++, old_block++, new_block++) {
3031                new_bh = sb_getblk(osb->sb, new_block);
3032                if (new_bh == NULL) {
3033                        ret = -ENOMEM;
3034                        mlog_errno(ret);
3035                        break;
3036                }
3037
3038                ocfs2_set_new_buffer_uptodate(ci, new_bh);
3039
3040                ret = ocfs2_read_block(ci, old_block, &old_bh, NULL);
3041                if (ret) {
3042                        mlog_errno(ret);
3043                        break;
3044                }
3045
3046                ret = ocfs2_journal_access(handle, ci, new_bh,
3047                                           OCFS2_JOURNAL_ACCESS_CREATE);
3048                if (ret) {
3049                        mlog_errno(ret);
3050                        break;
3051                }
3052
3053                memcpy(new_bh->b_data, old_bh->b_data, sb->s_blocksize);
3054                ocfs2_journal_dirty(handle, new_bh);
3055
3056                brelse(new_bh);
3057                brelse(old_bh);
3058                new_bh = NULL;
3059                old_bh = NULL;
3060        }
3061
3062        brelse(new_bh);
3063        brelse(old_bh);
3064        return ret;
3065}
3066
3067static int ocfs2_clear_ext_refcount(handle_t *handle,
3068                                    struct ocfs2_extent_tree *et,
3069                                    u32 cpos, u32 p_cluster, u32 len,
3070                                    unsigned int ext_flags,
3071                                    struct ocfs2_alloc_context *meta_ac,
3072                                    struct ocfs2_cached_dealloc_ctxt *dealloc)
3073{
3074        int ret, index;
3075        struct ocfs2_extent_rec replace_rec;
3076        struct ocfs2_path *path = NULL;
3077        struct ocfs2_extent_list *el;
3078        struct super_block *sb = ocfs2_metadata_cache_get_super(et->et_ci);
3079        u64 ino = ocfs2_metadata_cache_owner(et->et_ci);
3080
3081        trace_ocfs2_clear_ext_refcount((unsigned long long)ino,
3082                                       cpos, len, p_cluster, ext_flags);
3083
3084        memset(&replace_rec, 0, sizeof(replace_rec));
3085        replace_rec.e_cpos = cpu_to_le32(cpos);
3086        replace_rec.e_leaf_clusters = cpu_to_le16(len);
3087        replace_rec.e_blkno = cpu_to_le64(ocfs2_clusters_to_blocks(sb,
3088                                                                   p_cluster));
3089        replace_rec.e_flags = ext_flags;
3090        replace_rec.e_flags &= ~OCFS2_EXT_REFCOUNTED;
3091
3092        path = ocfs2_new_path_from_et(et);
3093        if (!path) {
3094                ret = -ENOMEM;
3095                mlog_errno(ret);
3096                goto out;
3097        }
3098
3099        ret = ocfs2_find_path(et->et_ci, path, cpos);
3100        if (ret) {
3101                mlog_errno(ret);
3102                goto out;
3103        }
3104
3105        el = path_leaf_el(path);
3106
3107        index = ocfs2_search_extent_list(el, cpos);
3108        if (index == -1) {
3109                ocfs2_error(sb,
3110                            "Inode %llu has an extent at cpos %u which can no "
3111                            "longer be found.\n",
3112                            (unsigned long long)ino, cpos);
3113                ret = -EROFS;
3114                goto out;
3115        }
3116
3117        ret = ocfs2_split_extent(handle, et, path, index,
3118                                 &replace_rec, meta_ac, dealloc);
3119        if (ret)
3120                mlog_errno(ret);
3121
3122out:
3123        ocfs2_free_path(path);
3124        return ret;
3125}
3126
3127static int ocfs2_replace_clusters(handle_t *handle,
3128                                  struct ocfs2_cow_context *context,
3129                                  u32 cpos, u32 old,
3130                                  u32 new, u32 len,
3131                                  unsigned int ext_flags)
3132{
3133        int ret;
3134        struct ocfs2_caching_info *ci = context->data_et.et_ci;
3135        u64 ino = ocfs2_metadata_cache_owner(ci);
3136
3137        trace_ocfs2_replace_clusters((unsigned long long)ino,
3138                                     cpos, old, new, len, ext_flags);
3139
3140        /*If the old clusters is unwritten, no need to duplicate. */
3141        if (!(ext_flags & OCFS2_EXT_UNWRITTEN)) {
3142                ret = context->cow_duplicate_clusters(handle, context->inode,
3143                                                      cpos, old, new, len);
3144                if (ret) {
3145                        mlog_errno(ret);
3146                        goto out;
3147                }
3148        }
3149
3150        ret = ocfs2_clear_ext_refcount(handle, &context->data_et,
3151                                       cpos, new, len, ext_flags,
3152                                       context->meta_ac, &context->dealloc);
3153        if (ret)
3154                mlog_errno(ret);
3155out:
3156        return ret;
3157}
3158
3159int ocfs2_cow_sync_writeback(struct super_block *sb,
3160                             struct inode *inode,
3161                             u32 cpos, u32 num_clusters)
3162{
3163        int ret = 0;
3164        loff_t offset, end, map_end;
3165        pgoff_t page_index;
3166        struct page *page;
3167
3168        if (ocfs2_should_order_data(inode))
3169                return 0;
3170
3171        offset = ((loff_t)cpos) << OCFS2_SB(sb)->s_clustersize_bits;
3172        end = offset + (num_clusters << OCFS2_SB(sb)->s_clustersize_bits);
3173
3174        ret = filemap_fdatawrite_range(inode->i_mapping,
3175                                       offset, end - 1);
3176        if (ret < 0) {
3177                mlog_errno(ret);
3178                return ret;
3179        }
3180
3181        while (offset < end) {
3182                page_index = offset >> PAGE_CACHE_SHIFT;
3183                map_end = ((loff_t)page_index + 1) << PAGE_CACHE_SHIFT;
3184                if (map_end > end)
3185                        map_end = end;
3186
3187                page = find_or_create_page(inode->i_mapping,
3188                                           page_index, GFP_NOFS);
3189                BUG_ON(!page);
3190
3191                wait_on_page_writeback(page);
3192                if (PageError(page)) {
3193                        ret = -EIO;
3194                        mlog_errno(ret);
3195                } else
3196                        mark_page_accessed(page);
3197
3198                unlock_page(page);
3199                page_cache_release(page);
3200                page = NULL;
3201                offset = map_end;
3202                if (ret)
3203                        break;
3204        }
3205
3206        return ret;
3207}
3208
3209static int ocfs2_di_get_clusters(struct ocfs2_cow_context *context,
3210                                 u32 v_cluster, u32 *p_cluster,
3211                                 u32 *num_clusters,
3212                                 unsigned int *extent_flags)
3213{
3214        return ocfs2_get_clusters(context->inode, v_cluster, p_cluster,
3215                                  num_clusters, extent_flags);
3216}
3217
3218static int ocfs2_make_clusters_writable(struct super_block *sb,
3219                                        struct ocfs2_cow_context *context,
3220                                        u32 cpos, u32 p_cluster,
3221                                        u32 num_clusters, unsigned int e_flags)
3222{
3223        int ret, delete, index, credits =  0;
3224        u32 new_bit, new_len, orig_num_clusters;
3225        unsigned int set_len;
3226        struct ocfs2_super *osb = OCFS2_SB(sb);
3227        handle_t *handle;
3228        struct buffer_head *ref_leaf_bh = NULL;
3229        struct ocfs2_caching_info *ref_ci = &context->ref_tree->rf_ci;
3230        struct ocfs2_refcount_rec rec;
3231
3232        trace_ocfs2_make_clusters_writable(cpos, p_cluster,
3233                                           num_clusters, e_flags);
3234
3235        ret = ocfs2_lock_refcount_allocators(sb, p_cluster, num_clusters,
3236                                             &context->data_et,
3237                                             ref_ci,
3238                                             context->ref_root_bh,
3239                                             &context->meta_ac,
3240                                             &context->data_ac, &credits);
3241        if (ret) {
3242                mlog_errno(ret);
3243                return ret;
3244        }
3245
3246        if (context->post_refcount)
3247                credits += context->post_refcount->credits;
3248
3249        credits += context->extra_credits;
3250        handle = ocfs2_start_trans(osb, credits);
3251        if (IS_ERR(handle)) {
3252                ret = PTR_ERR(handle);
3253                mlog_errno(ret);
3254                goto out;
3255        }
3256
3257        orig_num_clusters = num_clusters;
3258
3259        while (num_clusters) {
3260                ret = ocfs2_get_refcount_rec(ref_ci, context->ref_root_bh,
3261                                             p_cluster, num_clusters,
3262                                             &rec, &index, &ref_leaf_bh);
3263                if (ret) {
3264                        mlog_errno(ret);
3265                        goto out_commit;
3266                }
3267
3268                BUG_ON(!rec.r_refcount);
3269                set_len = min((u64)p_cluster + num_clusters,
3270                              le64_to_cpu(rec.r_cpos) +
3271                              le32_to_cpu(rec.r_clusters)) - p_cluster;
3272
3273                /*
3274                 * There are many different situation here.
3275                 * 1. If refcount == 1, remove the flag and don't COW.
3276                 * 2. If refcount > 1, allocate clusters.
3277                 *    Here we may not allocate r_len once at a time, so continue
3278                 *    until we reach num_clusters.
3279                 */
3280                if (le32_to_cpu(rec.r_refcount) == 1) {
3281                        delete = 0;
3282                        ret = ocfs2_clear_ext_refcount(handle,
3283                                                       &context->data_et,
3284                                                       cpos, p_cluster,
3285                                                       set_len, e_flags,
3286                                                       context->meta_ac,
3287                                                       &context->dealloc);
3288                        if (ret) {
3289                                mlog_errno(ret);
3290                                goto out_commit;
3291                        }
3292                } else {
3293                        delete = 1;
3294
3295                        ret = __ocfs2_claim_clusters(handle,
3296                                                     context->data_ac,
3297                                                     1, set_len,
3298                                                     &new_bit, &new_len);
3299                        if (ret) {
3300                                mlog_errno(ret);
3301                                goto out_commit;
3302                        }
3303
3304                        ret = ocfs2_replace_clusters(handle, context,
3305                                                     cpos, p_cluster, new_bit,
3306                                                     new_len, e_flags);
3307                        if (ret) {
3308                                mlog_errno(ret);
3309                                goto out_commit;
3310                        }
3311                        set_len = new_len;
3312                }
3313
3314                ret = __ocfs2_decrease_refcount(handle, ref_ci,
3315                                                context->ref_root_bh,
3316                                                p_cluster, set_len,
3317                                                context->meta_ac,
3318                                                &context->dealloc, delete);
3319                if (ret) {
3320                        mlog_errno(ret);
3321                        goto out_commit;
3322                }
3323
3324                cpos += set_len;
3325                p_cluster += set_len;
3326                num_clusters -= set_len;
3327                brelse(ref_leaf_bh);
3328                ref_leaf_bh = NULL;
3329        }
3330
3331        /* handle any post_cow action. */
3332        if (context->post_refcount && context->post_refcount->func) {
3333                ret = context->post_refcount->func(context->inode, handle,
3334                                                context->post_refcount->para);
3335                if (ret) {
3336                        mlog_errno(ret);
3337                        goto out_commit;
3338                }
3339        }
3340
3341        /*
3342         * Here we should write the new page out first if we are
3343         * in write-back mode.
3344         */
3345        if (context->get_clusters == ocfs2_di_get_clusters) {
3346                ret = ocfs2_cow_sync_writeback(sb, context->inode, cpos,
3347                                               orig_num_clusters);
3348                if (ret)
3349                        mlog_errno(ret);
3350        }
3351
3352out_commit:
3353        ocfs2_commit_trans(osb, handle);
3354
3355out:
3356        if (context->data_ac) {
3357                ocfs2_free_alloc_context(context->data_ac);
3358                context->data_ac = NULL;
3359        }
3360        if (context->meta_ac) {
3361                ocfs2_free_alloc_context(context->meta_ac);
3362                context->meta_ac = NULL;
3363        }
3364        brelse(ref_leaf_bh);
3365
3366        return ret;
3367}
3368
3369static int ocfs2_replace_cow(struct ocfs2_cow_context *context)
3370{
3371        int ret = 0;
3372        struct inode *inode = context->inode;
3373        u32 cow_start = context->cow_start, cow_len = context->cow_len;
3374        u32 p_cluster, num_clusters;
3375        unsigned int ext_flags;
3376        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
3377
3378        if (!ocfs2_refcount_tree(OCFS2_SB(inode->i_sb))) {
3379                ocfs2_error(inode->i_sb, "Inode %lu want to use refcount "
3380                            "tree, but the feature bit is not set in the "
3381                            "super block.", inode->i_ino);
3382                return -EROFS;
3383        }
3384
3385        ocfs2_init_dealloc_ctxt(&context->dealloc);
3386
3387        while (cow_len) {
3388                ret = context->get_clusters(context, cow_start, &p_cluster,
3389                                            &num_clusters, &ext_flags);
3390                if (ret) {
3391                        mlog_errno(ret);
3392                        break;
3393                }
3394
3395                BUG_ON(!(ext_flags & OCFS2_EXT_REFCOUNTED));
3396
3397                if (cow_len < num_clusters)
3398                        num_clusters = cow_len;
3399
3400                ret = ocfs2_make_clusters_writable(inode->i_sb, context,
3401                                                   cow_start, p_cluster,
3402                                                   num_clusters, ext_flags);
3403                if (ret) {
3404                        mlog_errno(ret);
3405                        break;
3406                }
3407
3408                cow_len -= num_clusters;
3409                cow_start += num_clusters;
3410        }
3411
3412        if (ocfs2_dealloc_has_cluster(&context->dealloc)) {
3413                ocfs2_schedule_truncate_log_flush(osb, 1);
3414                ocfs2_run_deallocs(osb, &context->dealloc);
3415        }
3416
3417        return ret;
3418}
3419
3420/*
3421 * Starting at cpos, try to CoW write_len clusters.  Don't CoW
3422 * past max_cpos.  This will stop when it runs into a hole or an
3423 * unrefcounted extent.
3424 */
3425static int ocfs2_refcount_cow_hunk(struct inode *inode,
3426                                   struct buffer_head *di_bh,
3427                                   u32 cpos, u32 write_len, u32 max_cpos)
3428{
3429        int ret;
3430        u32 cow_start = 0, cow_len = 0;
3431        struct ocfs2_inode_info *oi = OCFS2_I(inode);
3432        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
3433        struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
3434        struct buffer_head *ref_root_bh = NULL;
3435        struct ocfs2_refcount_tree *ref_tree;
3436        struct ocfs2_cow_context *context = NULL;
3437
3438        BUG_ON(!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL));
3439
3440        ret = ocfs2_refcount_cal_cow_clusters(inode, &di->id2.i_list,
3441                                              cpos, write_len, max_cpos,
3442                                              &cow_start, &cow_len);
3443        if (ret) {
3444                mlog_errno(ret);
3445                goto out;
3446        }
3447
3448        trace_ocfs2_refcount_cow_hunk(OCFS2_I(inode)->ip_blkno,
3449                                      cpos, write_len, max_cpos,
3450                                      cow_start, cow_len);
3451
3452        BUG_ON(cow_len == 0);
3453
3454        context = kzalloc(sizeof(struct ocfs2_cow_context), GFP_NOFS);
3455        if (!context) {
3456                ret = -ENOMEM;
3457                mlog_errno(ret);
3458                goto out;
3459        }
3460
3461        ret = ocfs2_lock_refcount_tree(osb, le64_to_cpu(di->i_refcount_loc),
3462                                       1, &ref_tree, &ref_root_bh);
3463        if (ret) {
3464                mlog_errno(ret);
3465                goto out;
3466        }
3467
3468        context->inode = inode;
3469        context->cow_start = cow_start;
3470        context->cow_len = cow_len;
3471        context->ref_tree = ref_tree;
3472        context->ref_root_bh = ref_root_bh;
3473        context->cow_duplicate_clusters = ocfs2_duplicate_clusters_by_page;
3474        context->get_clusters = ocfs2_di_get_clusters;
3475
3476        ocfs2_init_dinode_extent_tree(&context->data_et,
3477                                      INODE_CACHE(inode), di_bh);
3478
3479        ret = ocfs2_replace_cow(context);
3480        if (ret)
3481                mlog_errno(ret);
3482
3483        /*
3484         * truncate the extent map here since no matter whether we meet with
3485         * any error during the action, we shouldn't trust cached extent map
3486         * any more.
3487         */
3488        ocfs2_extent_map_trunc(inode, cow_start);
3489
3490        ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
3491        brelse(ref_root_bh);
3492out:
3493        kfree(context);
3494        return ret;
3495}
3496
3497/*
3498 * CoW any and all clusters between cpos and cpos+write_len.
3499 * Don't CoW past max_cpos.  If this returns successfully, all
3500 * clusters between cpos and cpos+write_len are safe to modify.
3501 */
3502int ocfs2_refcount_cow(struct inode *inode,
3503                       struct buffer_head *di_bh,
3504                       u32 cpos, u32 write_len, u32 max_cpos)
3505{
3506        int ret = 0;
3507        u32 p_cluster, num_clusters;
3508        unsigned int ext_flags;
3509
3510        while (write_len) {
3511                ret = ocfs2_get_clusters(inode, cpos, &p_cluster,
3512                                         &num_clusters, &ext_flags);
3513                if (ret) {
3514                        mlog_errno(ret);
3515                        break;
3516                }
3517
3518                if (write_len < num_clusters)
3519                        num_clusters = write_len;
3520
3521                if (ext_flags & OCFS2_EXT_REFCOUNTED) {
3522                        ret = ocfs2_refcount_cow_hunk(inode, di_bh, cpos,
3523                                                      num_clusters, max_cpos);
3524                        if (ret) {
3525                                mlog_errno(ret);
3526                                break;
3527                        }
3528                }
3529
3530                write_len -= num_clusters;
3531                cpos += num_clusters;
3532        }
3533
3534        return ret;
3535}
3536
3537static int ocfs2_xattr_value_get_clusters(struct ocfs2_cow_context *context,
3538                                          u32 v_cluster, u32 *p_cluster,
3539                                          u32 *num_clusters,
3540                                          unsigned int *extent_flags)
3541{
3542        struct inode *inode = context->inode;
3543        struct ocfs2_xattr_value_root *xv = context->cow_object;
3544
3545        return ocfs2_xattr_get_clusters(inode, v_cluster, p_cluster,
3546                                        num_clusters, &xv->xr_list,
3547                                        extent_flags);
3548}
3549
3550/*
3551 * Given a xattr value root, calculate the most meta/credits we need for
3552 * refcount tree change if we truncate it to 0.
3553 */
3554int ocfs2_refcounted_xattr_delete_need(struct inode *inode,
3555                                       struct ocfs2_caching_info *ref_ci,
3556                                       struct buffer_head *ref_root_bh,
3557                                       struct ocfs2_xattr_value_root *xv,
3558                                       int *meta_add, int *credits)
3559{
3560        int ret = 0, index, ref_blocks = 0;
3561        u32 p_cluster, num_clusters;
3562        u32 cpos = 0, clusters = le32_to_cpu(xv->xr_clusters);
3563        struct ocfs2_refcount_block *rb;
3564        struct ocfs2_refcount_rec rec;
3565        struct buffer_head *ref_leaf_bh = NULL;
3566
3567        while (cpos < clusters) {
3568                ret = ocfs2_xattr_get_clusters(inode, cpos, &p_cluster,
3569                                               &num_clusters, &xv->xr_list,
3570                                               NULL);
3571                if (ret) {
3572                        mlog_errno(ret);
3573                        goto out;
3574                }
3575
3576                cpos += num_clusters;
3577
3578                while (num_clusters) {
3579                        ret = ocfs2_get_refcount_rec(ref_ci, ref_root_bh,
3580                                                     p_cluster, num_clusters,
3581                                                     &rec, &index,
3582                                                     &ref_leaf_bh);
3583                        if (ret) {
3584                                mlog_errno(ret);
3585                                goto out;
3586                        }
3587
3588                        BUG_ON(!rec.r_refcount);
3589
3590                        rb = (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
3591
3592                        /*
3593                         * We really don't know whether the other clusters is in
3594                         * this refcount block or not, so just take the worst
3595                         * case that all the clusters are in this block and each
3596                         * one will split a refcount rec, so totally we need
3597                         * clusters * 2 new refcount rec.
3598                         */
3599                        if (le16_to_cpu(rb->rf_records.rl_used) + clusters * 2 >
3600                            le16_to_cpu(rb->rf_records.rl_count))
3601                                ref_blocks++;
3602
3603                        *credits += 1;
3604                        brelse(ref_leaf_bh);
3605                        ref_leaf_bh = NULL;
3606
3607                        if (num_clusters <= le32_to_cpu(rec.r_clusters))
3608                                break;
3609                        else
3610                                num_clusters -= le32_to_cpu(rec.r_clusters);
3611                        p_cluster += num_clusters;
3612                }
3613        }
3614
3615        *meta_add += ref_blocks;
3616        if (!ref_blocks)
3617                goto out;
3618
3619        rb = (struct ocfs2_refcount_block *)ref_root_bh->b_data;
3620        if (le32_to_cpu(rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL)
3621                *credits += OCFS2_EXPAND_REFCOUNT_TREE_CREDITS;
3622        else {
3623                struct ocfs2_extent_tree et;
3624
3625                ocfs2_init_refcount_extent_tree(&et, ref_ci, ref_root_bh);
3626                *credits += ocfs2_calc_extend_credits(inode->i_sb,
3627                                                      et.et_root_el);
3628        }
3629
3630out:
3631        brelse(ref_leaf_bh);
3632        return ret;
3633}
3634
3635/*
3636 * Do CoW for xattr.
3637 */
3638int ocfs2_refcount_cow_xattr(struct inode *inode,
3639                             struct ocfs2_dinode *di,
3640                             struct ocfs2_xattr_value_buf *vb,
3641                             struct ocfs2_refcount_tree *ref_tree,
3642                             struct buffer_head *ref_root_bh,
3643                             u32 cpos, u32 write_len,
3644                             struct ocfs2_post_refcount *post)
3645{
3646        int ret;
3647        struct ocfs2_xattr_value_root *xv = vb->vb_xv;
3648        struct ocfs2_inode_info *oi = OCFS2_I(inode);
3649        struct ocfs2_cow_context *context = NULL;
3650        u32 cow_start, cow_len;
3651
3652        BUG_ON(!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL));
3653
3654        ret = ocfs2_refcount_cal_cow_clusters(inode, &xv->xr_list,
3655                                              cpos, write_len, UINT_MAX,
3656                                              &cow_start, &cow_len);
3657        if (ret) {
3658                mlog_errno(ret);
3659                goto out;
3660        }
3661
3662        BUG_ON(cow_len == 0);
3663
3664        context = kzalloc(sizeof(struct ocfs2_cow_context), GFP_NOFS);
3665        if (!context) {
3666                ret = -ENOMEM;
3667                mlog_errno(ret);
3668                goto out;
3669        }
3670
3671        context->inode = inode;
3672        context->cow_start = cow_start;
3673        context->cow_len = cow_len;
3674        context->ref_tree = ref_tree;
3675        context->ref_root_bh = ref_root_bh;
3676        context->cow_object = xv;
3677
3678        context->cow_duplicate_clusters = ocfs2_duplicate_clusters_by_jbd;
3679        /* We need the extra credits for duplicate_clusters by jbd. */
3680        context->extra_credits =
3681                ocfs2_clusters_to_blocks(inode->i_sb, 1) * cow_len;
3682        context->get_clusters = ocfs2_xattr_value_get_clusters;
3683        context->post_refcount = post;
3684
3685        ocfs2_init_xattr_value_extent_tree(&context->data_et,
3686                                           INODE_CACHE(inode), vb);
3687
3688        ret = ocfs2_replace_cow(context);
3689        if (ret)
3690                mlog_errno(ret);
3691
3692out:
3693        kfree(context);
3694        return ret;
3695}
3696
3697/*
3698 * Insert a new extent into refcount tree and mark a extent rec
3699 * as refcounted in the dinode tree.
3700 */
3701int ocfs2_add_refcount_flag(struct inode *inode,
3702                            struct ocfs2_extent_tree *data_et,
3703                            struct ocfs2_caching_info *ref_ci,
3704                            struct buffer_head *ref_root_bh,
3705                            u32 cpos, u32 p_cluster, u32 num_clusters,
3706                            struct ocfs2_cached_dealloc_ctxt *dealloc,
3707                            struct ocfs2_post_refcount *post)
3708{
3709        int ret;
3710        handle_t *handle;
3711        int credits = 1, ref_blocks = 0;
3712        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
3713        struct ocfs2_alloc_context *meta_ac = NULL;
3714
3715        ret = ocfs2_calc_refcount_meta_credits(inode->i_sb,
3716                                               ref_ci, ref_root_bh,
3717                                               p_cluster, num_clusters,
3718                                               &ref_blocks, &credits);
3719        if (ret) {
3720                mlog_errno(ret);
3721                goto out;
3722        }
3723
3724        trace_ocfs2_add_refcount_flag(ref_blocks, credits);
3725
3726        if (ref_blocks) {
3727                ret = ocfs2_reserve_new_metadata_blocks(OCFS2_SB(inode->i_sb),
3728                                                        ref_blocks, &meta_ac);
3729                if (ret) {
3730                        mlog_errno(ret);
3731                        goto out;
3732                }
3733        }
3734
3735        if (post)
3736                credits += post->credits;
3737
3738        handle = ocfs2_start_trans(osb, credits);
3739        if (IS_ERR(handle)) {
3740                ret = PTR_ERR(handle);
3741                mlog_errno(ret);
3742                goto out;
3743        }
3744
3745        ret = ocfs2_mark_extent_refcounted(inode, data_et, handle,
3746                                           cpos, num_clusters, p_cluster,
3747                                           meta_ac, dealloc);
3748        if (ret) {
3749                mlog_errno(ret);
3750                goto out_commit;
3751        }
3752
3753        ret = __ocfs2_increase_refcount(handle, ref_ci, ref_root_bh,
3754                                        p_cluster, num_clusters, 0,
3755                                        meta_ac, dealloc);
3756        if (ret) {
3757                mlog_errno(ret);
3758                goto out_commit;
3759        }
3760
3761        if (post && post->func) {
3762                ret = post->func(inode, handle, post->para);
3763                if (ret)
3764                        mlog_errno(ret);
3765        }
3766
3767out_commit:
3768        ocfs2_commit_trans(osb, handle);
3769out:
3770        if (meta_ac)
3771                ocfs2_free_alloc_context(meta_ac);
3772        return ret;
3773}
3774
3775static int ocfs2_change_ctime(struct inode *inode,
3776                              struct buffer_head *di_bh)
3777{
3778        int ret;
3779        handle_t *handle;
3780        struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
3781
3782        handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb),
3783                                   OCFS2_INODE_UPDATE_CREDITS);
3784        if (IS_ERR(handle)) {
3785                ret = PTR_ERR(handle);
3786                mlog_errno(ret);
3787                goto out;
3788        }
3789
3790        ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
3791                                      OCFS2_JOURNAL_ACCESS_WRITE);
3792        if (ret) {
3793                mlog_errno(ret);
3794                goto out_commit;
3795        }
3796
3797        inode->i_ctime = CURRENT_TIME;
3798        di->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
3799        di->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
3800
3801        ocfs2_journal_dirty(handle, di_bh);
3802
3803out_commit:
3804        ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
3805out:
3806        return ret;
3807}
3808
3809static int ocfs2_attach_refcount_tree(struct inode *inode,
3810                                      struct buffer_head *di_bh)
3811{
3812        int ret, data_changed = 0;
3813        struct buffer_head *ref_root_bh = NULL;
3814        struct ocfs2_inode_info *oi = OCFS2_I(inode);
3815        struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
3816        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
3817        struct ocfs2_refcount_tree *ref_tree;
3818        unsigned int ext_flags;
3819        loff_t size;
3820        u32 cpos, num_clusters, clusters, p_cluster;
3821        struct ocfs2_cached_dealloc_ctxt dealloc;
3822        struct ocfs2_extent_tree di_et;
3823
3824        ocfs2_init_dealloc_ctxt(&dealloc);
3825
3826        if (!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL)) {
3827                ret = ocfs2_create_refcount_tree(inode, di_bh);
3828                if (ret) {
3829                        mlog_errno(ret);
3830                        goto out;
3831                }
3832        }
3833
3834        BUG_ON(!di->i_refcount_loc);
3835        ret = ocfs2_lock_refcount_tree(osb,
3836                                       le64_to_cpu(di->i_refcount_loc), 1,
3837                                       &ref_tree, &ref_root_bh);
3838        if (ret) {
3839                mlog_errno(ret);
3840                goto out;
3841        }
3842
3843        if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
3844                goto attach_xattr;
3845
3846        ocfs2_init_dinode_extent_tree(&di_et, INODE_CACHE(inode), di_bh);
3847
3848        size = i_size_read(inode);
3849        clusters = ocfs2_clusters_for_bytes(inode->i_sb, size);
3850
3851        cpos = 0;
3852        while (cpos < clusters) {
3853                ret = ocfs2_get_clusters(inode, cpos, &p_cluster,
3854                                         &num_clusters, &ext_flags);
3855                if (ret) {
3856                        mlog_errno(ret);
3857                        goto unlock;
3858                }
3859                if (p_cluster && !(ext_flags & OCFS2_EXT_REFCOUNTED)) {
3860                        ret = ocfs2_add_refcount_flag(inode, &di_et,
3861                                                      &ref_tree->rf_ci,
3862                                                      ref_root_bh, cpos,
3863                                                      p_cluster, num_clusters,
3864                                                      &dealloc, NULL);
3865                        if (ret) {
3866                                mlog_errno(ret);
3867                                goto unlock;
3868                        }
3869
3870                        data_changed = 1;
3871                }
3872                cpos += num_clusters;
3873        }
3874
3875attach_xattr:
3876        if (oi->ip_dyn_features & OCFS2_HAS_XATTR_FL) {
3877                ret = ocfs2_xattr_attach_refcount_tree(inode, di_bh,
3878                                                       &ref_tree->rf_ci,
3879                                                       ref_root_bh,
3880                                                       &dealloc);
3881                if (ret) {
3882                        mlog_errno(ret);
3883                        goto unlock;
3884                }
3885        }
3886
3887        if (data_changed) {
3888                ret = ocfs2_change_ctime(inode, di_bh);
3889                if (ret)
3890                        mlog_errno(ret);
3891        }
3892
3893unlock:
3894        ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
3895        brelse(ref_root_bh);
3896
3897        if (!ret && ocfs2_dealloc_has_cluster(&dealloc)) {
3898                ocfs2_schedule_truncate_log_flush(osb, 1);
3899                ocfs2_run_deallocs(osb, &dealloc);
3900        }
3901out:
3902        /*
3903         * Empty the extent map so that we may get the right extent
3904         * record from the disk.
3905         */
3906        ocfs2_extent_map_trunc(inode, 0);
3907
3908        return ret;
3909}
3910
3911static int ocfs2_add_refcounted_extent(struct inode *inode,
3912                                   struct ocfs2_extent_tree *et,
3913                                   struct ocfs2_caching_info *ref_ci,
3914                                   struct buffer_head *ref_root_bh,
3915                                   u32 cpos, u32 p_cluster, u32 num_clusters,
3916                                   unsigned int ext_flags,
3917                                   struct ocfs2_cached_dealloc_ctxt *dealloc)
3918{
3919        int ret;
3920        handle_t *handle;
3921        int credits = 0;
3922        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
3923        struct ocfs2_alloc_context *meta_ac = NULL;
3924
3925        ret = ocfs2_lock_refcount_allocators(inode->i_sb,
3926                                             p_cluster, num_clusters,
3927                                             et, ref_ci,
3928                                             ref_root_bh, &meta_ac,
3929                                             NULL, &credits);
3930        if (ret) {
3931                mlog_errno(ret);
3932                goto out;
3933        }
3934
3935        handle = ocfs2_start_trans(osb, credits);
3936        if (IS_ERR(handle)) {
3937                ret = PTR_ERR(handle);
3938                mlog_errno(ret);
3939                goto out;
3940        }
3941
3942        ret = ocfs2_insert_extent(handle, et, cpos,
3943                        ocfs2_clusters_to_blocks(inode->i_sb, p_cluster),
3944                        num_clusters, ext_flags, meta_ac);
3945        if (ret) {
3946                mlog_errno(ret);
3947                goto out_commit;
3948        }
3949
3950        ret = ocfs2_increase_refcount(handle, ref_ci, ref_root_bh,
3951                                      p_cluster, num_clusters,
3952                                      meta_ac, dealloc);
3953        if (ret)
3954                mlog_errno(ret);
3955
3956out_commit:
3957        ocfs2_commit_trans(osb, handle);
3958out:
3959        if (meta_ac)
3960                ocfs2_free_alloc_context(meta_ac);
3961        return ret;
3962}
3963
3964static int ocfs2_duplicate_inline_data(struct inode *s_inode,
3965                                       struct buffer_head *s_bh,
3966                                       struct inode *t_inode,
3967                                       struct buffer_head *t_bh)
3968{
3969        int ret;
3970        handle_t *handle;
3971        struct ocfs2_super *osb = OCFS2_SB(s_inode->i_sb);
3972        struct ocfs2_dinode *s_di = (struct ocfs2_dinode *)s_bh->b_data;
3973        struct ocfs2_dinode *t_di = (struct ocfs2_dinode *)t_bh->b_data;
3974
3975        BUG_ON(!(OCFS2_I(s_inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL));
3976
3977        handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
3978        if (IS_ERR(handle)) {
3979                ret = PTR_ERR(handle);
3980                mlog_errno(ret);
3981                goto out;
3982        }
3983
3984        ret = ocfs2_journal_access_di(handle, INODE_CACHE(t_inode), t_bh,
3985                                      OCFS2_JOURNAL_ACCESS_WRITE);
3986        if (ret) {
3987                mlog_errno(ret);
3988                goto out_commit;
3989        }
3990
3991        t_di->id2.i_data.id_count = s_di->id2.i_data.id_count;
3992        memcpy(t_di->id2.i_data.id_data, s_di->id2.i_data.id_data,
3993               le16_to_cpu(s_di->id2.i_data.id_count));
3994        spin_lock(&OCFS2_I(t_inode)->ip_lock);
3995        OCFS2_I(t_inode)->ip_dyn_features |= OCFS2_INLINE_DATA_FL;
3996        t_di->i_dyn_features = cpu_to_le16(OCFS2_I(t_inode)->ip_dyn_features);
3997        spin_unlock(&OCFS2_I(t_inode)->ip_lock);
3998
3999        ocfs2_journal_dirty(handle, t_bh);
4000
4001out_commit:
4002        ocfs2_commit_trans(osb, handle);
4003out:
4004        return ret;
4005}
4006
4007static int ocfs2_duplicate_extent_list(struct inode *s_inode,
4008                                struct inode *t_inode,
4009                                struct buffer_head *t_bh,
4010                                struct ocfs2_caching_info *ref_ci,
4011                                struct buffer_head *ref_root_bh,
4012                                struct ocfs2_cached_dealloc_ctxt *dealloc)
4013{
4014        int ret = 0;
4015        u32 p_cluster, num_clusters, clusters, cpos;
4016        loff_t size;
4017        unsigned int ext_flags;
4018        struct ocfs2_extent_tree et;
4019
4020        ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(t_inode), t_bh);
4021
4022        size = i_size_read(s_inode);
4023        clusters = ocfs2_clusters_for_bytes(s_inode->i_sb, size);
4024
4025        cpos = 0;
4026        while (cpos < clusters) {
4027                ret = ocfs2_get_clusters(s_inode, cpos, &p_cluster,
4028                                         &num_clusters, &ext_flags);
4029                if (ret) {
4030                        mlog_errno(ret);
4031                        goto out;
4032                }
4033                if (p_cluster) {
4034                        ret = ocfs2_add_refcounted_extent(t_inode, &et,
4035                                                          ref_ci, ref_root_bh,
4036                                                          cpos, p_cluster,
4037                                                          num_clusters,
4038                                                          ext_flags,
4039                                                          dealloc);
4040                        if (ret) {
4041                                mlog_errno(ret);
4042                                goto out;
4043                        }
4044                }
4045
4046                cpos += num_clusters;
4047        }
4048
4049out:
4050        return ret;
4051}
4052
4053/*
4054 * change the new file's attributes to the src.
4055 *
4056 * reflink creates a snapshot of a file, that means the attributes
4057 * must be identical except for three exceptions - nlink, ino, and ctime.
4058 */
4059static int ocfs2_complete_reflink(struct inode *s_inode,
4060                                  struct buffer_head *s_bh,
4061                                  struct inode *t_inode,
4062                                  struct buffer_head *t_bh,
4063                                  bool preserve)
4064{
4065        int ret;
4066        handle_t *handle;
4067        struct ocfs2_dinode *s_di = (struct ocfs2_dinode *)s_bh->b_data;
4068        struct ocfs2_dinode *di = (struct ocfs2_dinode *)t_bh->b_data;
4069        loff_t size = i_size_read(s_inode);
4070
4071        handle = ocfs2_start_trans(OCFS2_SB(t_inode->i_sb),
4072                                   OCFS2_INODE_UPDATE_CREDITS);
4073        if (IS_ERR(handle)) {
4074                ret = PTR_ERR(handle);
4075                mlog_errno(ret);
4076                return ret;
4077        }
4078
4079        ret = ocfs2_journal_access_di(handle, INODE_CACHE(t_inode), t_bh,
4080                                      OCFS2_JOURNAL_ACCESS_WRITE);
4081        if (ret) {
4082                mlog_errno(ret);
4083                goto out_commit;
4084        }
4085
4086        spin_lock(&OCFS2_I(t_inode)->ip_lock);
4087        OCFS2_I(t_inode)->ip_clusters = OCFS2_I(s_inode)->ip_clusters;
4088        OCFS2_I(t_inode)->ip_attr = OCFS2_I(s_inode)->ip_attr;
4089        OCFS2_I(t_inode)->ip_dyn_features = OCFS2_I(s_inode)->ip_dyn_features;
4090        spin_unlock(&OCFS2_I(t_inode)->ip_lock);
4091        i_size_write(t_inode, size);
4092        t_inode->i_blocks = s_inode->i_blocks;
4093
4094        di->i_xattr_inline_size = s_di->i_xattr_inline_size;
4095        di->i_clusters = s_di->i_clusters;
4096        di->i_size = s_di->i_size;
4097        di->i_dyn_features = s_di->i_dyn_features;
4098        di->i_attr = s_di->i_attr;
4099
4100        if (preserve) {
4101                t_inode->i_uid = s_inode->i_uid;
4102                t_inode->i_gid = s_inode->i_gid;
4103                t_inode->i_mode = s_inode->i_mode;
4104                di->i_uid = s_di->i_uid;
4105                di->i_gid = s_di->i_gid;
4106                di->i_mode = s_di->i_mode;
4107
4108                /*
4109                 * update time.
4110                 * we want mtime to appear identical to the source and
4111                 * update ctime.
4112                 */
4113                t_inode->i_ctime = CURRENT_TIME;
4114
4115                di->i_ctime = cpu_to_le64(t_inode->i_ctime.tv_sec);
4116                di->i_ctime_nsec = cpu_to_le32(t_inode->i_ctime.tv_nsec);
4117
4118                t_inode->i_mtime = s_inode->i_mtime;
4119                di->i_mtime = s_di->i_mtime;
4120                di->i_mtime_nsec = s_di->i_mtime_nsec;
4121        }
4122
4123        ocfs2_journal_dirty(handle, t_bh);
4124
4125out_commit:
4126        ocfs2_commit_trans(OCFS2_SB(t_inode->i_sb), handle);
4127        return ret;
4128}
4129
4130static int ocfs2_create_reflink_node(struct inode *s_inode,
4131                                     struct buffer_head *s_bh,
4132                                     struct inode *t_inode,
4133                                     struct buffer_head *t_bh,
4134                                     bool preserve)
4135{
4136        int ret;
4137        struct buffer_head *ref_root_bh = NULL;
4138        struct ocfs2_cached_dealloc_ctxt dealloc;
4139        struct ocfs2_super *osb = OCFS2_SB(s_inode->i_sb);
4140        struct ocfs2_refcount_block *rb;
4141        struct ocfs2_dinode *di = (struct ocfs2_dinode *)s_bh->b_data;
4142        struct ocfs2_refcount_tree *ref_tree;
4143
4144        ocfs2_init_dealloc_ctxt(&dealloc);
4145
4146        ret = ocfs2_set_refcount_tree(t_inode, t_bh,
4147                                      le64_to_cpu(di->i_refcount_loc));
4148        if (ret) {
4149                mlog_errno(ret);
4150                goto out;
4151        }
4152
4153        if (OCFS2_I(s_inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
4154                ret = ocfs2_duplicate_inline_data(s_inode, s_bh,
4155                                                  t_inode, t_bh);
4156                if (ret)
4157                        mlog_errno(ret);
4158                goto out;
4159        }
4160
4161        ret = ocfs2_lock_refcount_tree(osb, le64_to_cpu(di->i_refcount_loc),
4162                                       1, &ref_tree, &ref_root_bh);
4163        if (ret) {
4164                mlog_errno(ret);
4165                goto out;
4166        }
4167        rb = (struct ocfs2_refcount_block *)ref_root_bh->b_data;
4168
4169        ret = ocfs2_duplicate_extent_list(s_inode, t_inode, t_bh,
4170                                          &ref_tree->rf_ci, ref_root_bh,
4171                                          &dealloc);
4172        if (ret) {
4173                mlog_errno(ret);
4174                goto out_unlock_refcount;
4175        }
4176
4177out_unlock_refcount:
4178        ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
4179        brelse(ref_root_bh);
4180out:
4181        if (ocfs2_dealloc_has_cluster(&dealloc)) {
4182                ocfs2_schedule_truncate_log_flush(osb, 1);
4183                ocfs2_run_deallocs(osb, &dealloc);
4184        }
4185
4186        return ret;
4187}
4188
4189static int __ocfs2_reflink(struct dentry *old_dentry,
4190                           struct buffer_head *old_bh,
4191                           struct inode *new_inode,
4192                           bool preserve)
4193{
4194        int ret;
4195        struct inode *inode = d_inode(old_dentry);
4196        struct buffer_head *new_bh = NULL;
4197
4198        if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE) {
4199                ret = -EINVAL;
4200                mlog_errno(ret);
4201                goto out;
4202        }
4203
4204        ret = filemap_fdatawrite(inode->i_mapping);
4205        if (ret) {
4206                mlog_errno(ret);
4207                goto out;
4208        }
4209
4210        ret = ocfs2_attach_refcount_tree(inode, old_bh);
4211        if (ret) {
4212                mlog_errno(ret);
4213                goto out;
4214        }
4215
4216        mutex_lock_nested(&new_inode->i_mutex, I_MUTEX_CHILD);
4217        ret = ocfs2_inode_lock_nested(new_inode, &new_bh, 1,
4218                                      OI_LS_REFLINK_TARGET);
4219        if (ret) {
4220                mlog_errno(ret);
4221                goto out_unlock;
4222        }
4223
4224        ret = ocfs2_create_reflink_node(inode, old_bh,
4225                                        new_inode, new_bh, preserve);
4226        if (ret) {
4227                mlog_errno(ret);
4228                goto inode_unlock;
4229        }
4230
4231        if (OCFS2_I(inode)->ip_dyn_features & OCFS2_HAS_XATTR_FL) {
4232                ret = ocfs2_reflink_xattrs(inode, old_bh,
4233                                           new_inode, new_bh,
4234                                           preserve);
4235                if (ret) {
4236                        mlog_errno(ret);
4237                        goto inode_unlock;
4238                }
4239        }
4240
4241        ret = ocfs2_complete_reflink(inode, old_bh,
4242                                     new_inode, new_bh, preserve);
4243        if (ret)
4244                mlog_errno(ret);
4245
4246inode_unlock:
4247        ocfs2_inode_unlock(new_inode, 1);
4248        brelse(new_bh);
4249out_unlock:
4250        mutex_unlock(&new_inode->i_mutex);
4251out:
4252        if (!ret) {
4253                ret = filemap_fdatawait(inode->i_mapping);
4254                if (ret)
4255                        mlog_errno(ret);
4256        }
4257        return ret;
4258}
4259
4260static int ocfs2_reflink(struct dentry *old_dentry, struct inode *dir,
4261                         struct dentry *new_dentry, bool preserve)
4262{
4263        int error;
4264        struct inode *inode = d_inode(old_dentry);
4265        struct buffer_head *old_bh = NULL;
4266        struct inode *new_orphan_inode = NULL;
4267        struct posix_acl *default_acl, *acl;
4268        umode_t mode;
4269
4270        if (!ocfs2_refcount_tree(OCFS2_SB(inode->i_sb)))
4271                return -EOPNOTSUPP;
4272
4273        mode = inode->i_mode;
4274        error = posix_acl_create(dir, &mode, &default_acl, &acl);
4275        if (error) {
4276                mlog_errno(error);
4277                return error;
4278        }
4279
4280        error = ocfs2_create_inode_in_orphan(dir, mode,
4281                                             &new_orphan_inode);
4282        if (error) {
4283                mlog_errno(error);
4284                goto out;
4285        }
4286
4287        error = ocfs2_rw_lock(inode, 1);
4288        if (error) {
4289                mlog_errno(error);
4290                goto out;
4291        }
4292
4293        error = ocfs2_inode_lock(inode, &old_bh, 1);
4294        if (error) {
4295                mlog_errno(error);
4296                ocfs2_rw_unlock(inode, 1);
4297                goto out;
4298        }
4299
4300        down_write(&OCFS2_I(inode)->ip_xattr_sem);
4301        down_write(&OCFS2_I(inode)->ip_alloc_sem);
4302        error = __ocfs2_reflink(old_dentry, old_bh,
4303                                new_orphan_inode, preserve);
4304        up_write(&OCFS2_I(inode)->ip_alloc_sem);
4305        up_write(&OCFS2_I(inode)->ip_xattr_sem);
4306
4307        ocfs2_inode_unlock(inode, 1);
4308        ocfs2_rw_unlock(inode, 1);
4309        brelse(old_bh);
4310
4311        if (error) {
4312                mlog_errno(error);
4313                goto out;
4314        }
4315
4316        /* If the security isn't preserved, we need to re-initialize them. */
4317        if (!preserve) {
4318                error = ocfs2_init_security_and_acl(dir, new_orphan_inode,
4319                                                    &new_dentry->d_name,
4320                                                    default_acl, acl);
4321                if (error)
4322                        mlog_errno(error);
4323        }
4324out:
4325        if (default_acl)
4326                posix_acl_release(default_acl);
4327        if (acl)
4328                posix_acl_release(acl);
4329        if (!error) {
4330                error = ocfs2_mv_orphaned_inode_to_new(dir, new_orphan_inode,
4331                                                       new_dentry);
4332                if (error)
4333                        mlog_errno(error);
4334        }
4335
4336        if (new_orphan_inode) {
4337                /*
4338                 * We need to open_unlock the inode no matter whether we
4339                 * succeed or not, so that other nodes can delete it later.
4340                 */
4341                ocfs2_open_unlock(new_orphan_inode);
4342                if (error)
4343                        iput(new_orphan_inode);
4344        }
4345
4346        return error;
4347}
4348
4349/*
4350 * Below here are the bits used by OCFS2_IOC_REFLINK() to fake
4351 * sys_reflink().  This will go away when vfs_reflink() exists in
4352 * fs/namei.c.
4353 */
4354
4355/* copied from may_create in VFS. */
4356static inline int ocfs2_may_create(struct inode *dir, struct dentry *child)
4357{
4358        if (d_really_is_positive(child))
4359                return -EEXIST;
4360        if (IS_DEADDIR(dir))
4361                return -ENOENT;
4362        return inode_permission(dir, MAY_WRITE | MAY_EXEC);
4363}
4364
4365/**
4366 * ocfs2_vfs_reflink - Create a reference-counted link
4367 *
4368 * @old_dentry:        source dentry + inode
4369 * @dir:       directory to create the target
4370 * @new_dentry:        target dentry
4371 * @preserve:  if true, preserve all file attributes
4372 */
4373static int ocfs2_vfs_reflink(struct dentry *old_dentry, struct inode *dir,
4374                             struct dentry *new_dentry, bool preserve)
4375{
4376        struct inode *inode = d_inode(old_dentry);
4377        int error;
4378
4379        if (!inode)
4380                return -ENOENT;
4381
4382        error = ocfs2_may_create(dir, new_dentry);
4383        if (error)
4384                return error;
4385
4386        if (dir->i_sb != inode->i_sb)
4387                return -EXDEV;
4388
4389        /*
4390         * A reflink to an append-only or immutable file cannot be created.
4391         */
4392        if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
4393                return -EPERM;
4394
4395        /* Only regular files can be reflinked. */
4396        if (!S_ISREG(inode->i_mode))
4397                return -EPERM;
4398
4399        /*
4400         * If the caller wants to preserve ownership, they require the
4401         * rights to do so.
4402         */
4403        if (preserve) {
4404                if (!uid_eq(current_fsuid(), inode->i_uid) && !capable(CAP_CHOWN))
4405                        return -EPERM;
4406                if (!in_group_p(inode->i_gid) && !capable(CAP_CHOWN))
4407                        return -EPERM;
4408        }
4409
4410        /*
4411         * If the caller is modifying any aspect of the attributes, they
4412         * are not creating a snapshot.  They need read permission on the
4413         * file.
4414         */
4415        if (!preserve) {
4416                error = inode_permission(inode, MAY_READ);
4417                if (error)
4418                        return error;
4419        }
4420
4421        mutex_lock(&inode->i_mutex);
4422        dquot_initialize(dir);
4423        error = ocfs2_reflink(old_dentry, dir, new_dentry, preserve);
4424        mutex_unlock(&inode->i_mutex);
4425        if (!error)
4426                fsnotify_create(dir, new_dentry);
4427        return error;
4428}
4429/*
4430 * Most codes are copied from sys_linkat.
4431 */
4432int ocfs2_reflink_ioctl(struct inode *inode,
4433                        const char __user *oldname,
4434                        const char __user *newname,
4435                        bool preserve)
4436{
4437        struct dentry *new_dentry;
4438        struct path old_path, new_path;
4439        int error;
4440
4441        if (!ocfs2_refcount_tree(OCFS2_SB(inode->i_sb)))
4442                return -EOPNOTSUPP;
4443
4444        error = user_path_at(AT_FDCWD, oldname, 0, &old_path);
4445        if (error) {
4446                mlog_errno(error);
4447                return error;
4448        }
4449
4450        new_dentry = user_path_create(AT_FDCWD, newname, &new_path, 0);
4451        error = PTR_ERR(new_dentry);
4452        if (IS_ERR(new_dentry)) {
4453                mlog_errno(error);
4454                goto out;
4455        }
4456
4457        error = -EXDEV;
4458        if (old_path.mnt != new_path.mnt) {
4459                mlog_errno(error);
4460                goto out_dput;
4461        }
4462
4463        error = ocfs2_vfs_reflink(old_path.dentry,
4464                                  d_inode(new_path.dentry),
4465                                  new_dentry, preserve);
4466out_dput:
4467        done_path_create(&new_path, new_dentry);
4468out:
4469        path_put(&old_path);
4470
4471        return error;
4472}
4473