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
  50struct ocfs2_cow_context {
  51        struct inode *inode;
  52        struct file *file;
  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 file *file,
  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        ocfs2_set_new_buffer_uptodate(&new_tree->rf_ci, new_bh);
 617
 618        ret = ocfs2_journal_access_rb(handle, &new_tree->rf_ci, new_bh,
 619                                      OCFS2_JOURNAL_ACCESS_CREATE);
 620        if (ret) {
 621                mlog_errno(ret);
 622                goto out_commit;
 623        }
 624
 625        /* Initialize ocfs2_refcount_block. */
 626        rb = (struct ocfs2_refcount_block *)new_bh->b_data;
 627        memset(rb, 0, inode->i_sb->s_blocksize);
 628        strcpy((void *)rb, OCFS2_REFCOUNT_BLOCK_SIGNATURE);
 629        rb->rf_suballoc_slot = cpu_to_le16(meta_ac->ac_alloc_slot);
 630        rb->rf_suballoc_loc = cpu_to_le64(suballoc_loc);
 631        rb->rf_suballoc_bit = cpu_to_le16(suballoc_bit_start);
 632        rb->rf_fs_generation = cpu_to_le32(osb->fs_generation);
 633        rb->rf_blkno = cpu_to_le64(first_blkno);
 634        rb->rf_count = cpu_to_le32(1);
 635        rb->rf_records.rl_count =
 636                        cpu_to_le16(ocfs2_refcount_recs_per_rb(osb->sb));
 637        spin_lock(&osb->osb_lock);
 638        rb->rf_generation = osb->s_next_generation++;
 639        spin_unlock(&osb->osb_lock);
 640
 641        ocfs2_journal_dirty(handle, new_bh);
 642
 643        spin_lock(&oi->ip_lock);
 644        oi->ip_dyn_features |= OCFS2_HAS_REFCOUNT_FL;
 645        di->i_dyn_features = cpu_to_le16(oi->ip_dyn_features);
 646        di->i_refcount_loc = cpu_to_le64(first_blkno);
 647        spin_unlock(&oi->ip_lock);
 648
 649        trace_ocfs2_create_refcount_tree_blkno((unsigned long long)first_blkno);
 650
 651        ocfs2_journal_dirty(handle, di_bh);
 652
 653        /*
 654         * We have to init the tree lock here since it will use
 655         * the generation number to create it.
 656         */
 657        new_tree->rf_generation = le32_to_cpu(rb->rf_generation);
 658        ocfs2_init_refcount_tree_lock(osb, new_tree, first_blkno,
 659                                      new_tree->rf_generation);
 660
 661        spin_lock(&osb->osb_lock);
 662        tree = ocfs2_find_refcount_tree(osb, first_blkno);
 663
 664        /*
 665         * We've just created a new refcount tree in this block.  If
 666         * we found a refcount tree on the ocfs2_super, it must be
 667         * one we just deleted.  We free the old tree before
 668         * inserting the new tree.
 669         */
 670        BUG_ON(tree && tree->rf_generation == new_tree->rf_generation);
 671        if (tree)
 672                ocfs2_erase_refcount_tree_from_list_no_lock(osb, tree);
 673        ocfs2_insert_refcount_tree(osb, new_tree);
 674        spin_unlock(&osb->osb_lock);
 675        new_tree = NULL;
 676        if (tree)
 677                ocfs2_refcount_tree_put(tree);
 678
 679out_commit:
 680        ocfs2_commit_trans(osb, handle);
 681
 682out:
 683        if (new_tree) {
 684                ocfs2_metadata_cache_exit(&new_tree->rf_ci);
 685                kfree(new_tree);
 686        }
 687
 688        brelse(new_bh);
 689        if (meta_ac)
 690                ocfs2_free_alloc_context(meta_ac);
 691
 692        return ret;
 693}
 694
 695static int ocfs2_set_refcount_tree(struct inode *inode,
 696                                   struct buffer_head *di_bh,
 697                                   u64 refcount_loc)
 698{
 699        int ret;
 700        handle_t *handle = NULL;
 701        struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
 702        struct ocfs2_inode_info *oi = OCFS2_I(inode);
 703        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 704        struct buffer_head *ref_root_bh = NULL;
 705        struct ocfs2_refcount_block *rb;
 706        struct ocfs2_refcount_tree *ref_tree;
 707
 708        BUG_ON(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL);
 709
 710        ret = ocfs2_lock_refcount_tree(osb, refcount_loc, 1,
 711                                       &ref_tree, &ref_root_bh);
 712        if (ret) {
 713                mlog_errno(ret);
 714                return ret;
 715        }
 716
 717        handle = ocfs2_start_trans(osb, OCFS2_REFCOUNT_TREE_SET_CREDITS);
 718        if (IS_ERR(handle)) {
 719                ret = PTR_ERR(handle);
 720                mlog_errno(ret);
 721                goto out;
 722        }
 723
 724        ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
 725                                      OCFS2_JOURNAL_ACCESS_WRITE);
 726        if (ret) {
 727                mlog_errno(ret);
 728                goto out_commit;
 729        }
 730
 731        ret = ocfs2_journal_access_rb(handle, &ref_tree->rf_ci, ref_root_bh,
 732                                      OCFS2_JOURNAL_ACCESS_WRITE);
 733        if (ret) {
 734                mlog_errno(ret);
 735                goto out_commit;
 736        }
 737
 738        rb = (struct ocfs2_refcount_block *)ref_root_bh->b_data;
 739        le32_add_cpu(&rb->rf_count, 1);
 740
 741        ocfs2_journal_dirty(handle, ref_root_bh);
 742
 743        spin_lock(&oi->ip_lock);
 744        oi->ip_dyn_features |= OCFS2_HAS_REFCOUNT_FL;
 745        di->i_dyn_features = cpu_to_le16(oi->ip_dyn_features);
 746        di->i_refcount_loc = cpu_to_le64(refcount_loc);
 747        spin_unlock(&oi->ip_lock);
 748        ocfs2_journal_dirty(handle, di_bh);
 749
 750out_commit:
 751        ocfs2_commit_trans(osb, handle);
 752out:
 753        ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
 754        brelse(ref_root_bh);
 755
 756        return ret;
 757}
 758
 759int ocfs2_remove_refcount_tree(struct inode *inode, struct buffer_head *di_bh)
 760{
 761        int ret, delete_tree = 0;
 762        handle_t *handle = NULL;
 763        struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
 764        struct ocfs2_inode_info *oi = OCFS2_I(inode);
 765        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 766        struct ocfs2_refcount_block *rb;
 767        struct inode *alloc_inode = NULL;
 768        struct buffer_head *alloc_bh = NULL;
 769        struct buffer_head *blk_bh = NULL;
 770        struct ocfs2_refcount_tree *ref_tree;
 771        int credits = OCFS2_REFCOUNT_TREE_REMOVE_CREDITS;
 772        u64 blk = 0, bg_blkno = 0, ref_blkno = le64_to_cpu(di->i_refcount_loc);
 773        u16 bit = 0;
 774
 775        if (!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL))
 776                return 0;
 777
 778        BUG_ON(!ref_blkno);
 779        ret = ocfs2_lock_refcount_tree(osb, ref_blkno, 1, &ref_tree, &blk_bh);
 780        if (ret) {
 781                mlog_errno(ret);
 782                return ret;
 783        }
 784
 785        rb = (struct ocfs2_refcount_block *)blk_bh->b_data;
 786
 787        /*
 788         * If we are the last user, we need to free the block.
 789         * So lock the allocator ahead.
 790         */
 791        if (le32_to_cpu(rb->rf_count) == 1) {
 792                blk = le64_to_cpu(rb->rf_blkno);
 793                bit = le16_to_cpu(rb->rf_suballoc_bit);
 794                if (rb->rf_suballoc_loc)
 795                        bg_blkno = le64_to_cpu(rb->rf_suballoc_loc);
 796                else
 797                        bg_blkno = ocfs2_which_suballoc_group(blk, bit);
 798
 799                alloc_inode = ocfs2_get_system_file_inode(osb,
 800                                        EXTENT_ALLOC_SYSTEM_INODE,
 801                                        le16_to_cpu(rb->rf_suballoc_slot));
 802                if (!alloc_inode) {
 803                        ret = -ENOMEM;
 804                        mlog_errno(ret);
 805                        goto out;
 806                }
 807                mutex_lock(&alloc_inode->i_mutex);
 808
 809                ret = ocfs2_inode_lock(alloc_inode, &alloc_bh, 1);
 810                if (ret) {
 811                        mlog_errno(ret);
 812                        goto out_mutex;
 813                }
 814
 815                credits += OCFS2_SUBALLOC_FREE;
 816        }
 817
 818        handle = ocfs2_start_trans(osb, credits);
 819        if (IS_ERR(handle)) {
 820                ret = PTR_ERR(handle);
 821                mlog_errno(ret);
 822                goto out_unlock;
 823        }
 824
 825        ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
 826                                      OCFS2_JOURNAL_ACCESS_WRITE);
 827        if (ret) {
 828                mlog_errno(ret);
 829                goto out_commit;
 830        }
 831
 832        ret = ocfs2_journal_access_rb(handle, &ref_tree->rf_ci, blk_bh,
 833                                      OCFS2_JOURNAL_ACCESS_WRITE);
 834        if (ret) {
 835                mlog_errno(ret);
 836                goto out_commit;
 837        }
 838
 839        spin_lock(&oi->ip_lock);
 840        oi->ip_dyn_features &= ~OCFS2_HAS_REFCOUNT_FL;
 841        di->i_dyn_features = cpu_to_le16(oi->ip_dyn_features);
 842        di->i_refcount_loc = 0;
 843        spin_unlock(&oi->ip_lock);
 844        ocfs2_journal_dirty(handle, di_bh);
 845
 846        le32_add_cpu(&rb->rf_count , -1);
 847        ocfs2_journal_dirty(handle, blk_bh);
 848
 849        if (!rb->rf_count) {
 850                delete_tree = 1;
 851                ocfs2_erase_refcount_tree_from_list(osb, ref_tree);
 852                ret = ocfs2_free_suballoc_bits(handle, alloc_inode,
 853                                               alloc_bh, bit, bg_blkno, 1);
 854                if (ret)
 855                        mlog_errno(ret);
 856        }
 857
 858out_commit:
 859        ocfs2_commit_trans(osb, handle);
 860out_unlock:
 861        if (alloc_inode) {
 862                ocfs2_inode_unlock(alloc_inode, 1);
 863                brelse(alloc_bh);
 864        }
 865out_mutex:
 866        if (alloc_inode) {
 867                mutex_unlock(&alloc_inode->i_mutex);
 868                iput(alloc_inode);
 869        }
 870out:
 871        ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
 872        if (delete_tree)
 873                ocfs2_refcount_tree_put(ref_tree);
 874        brelse(blk_bh);
 875
 876        return ret;
 877}
 878
 879static void ocfs2_find_refcount_rec_in_rl(struct ocfs2_caching_info *ci,
 880                                          struct buffer_head *ref_leaf_bh,
 881                                          u64 cpos, unsigned int len,
 882                                          struct ocfs2_refcount_rec *ret_rec,
 883                                          int *index)
 884{
 885        int i = 0;
 886        struct ocfs2_refcount_block *rb =
 887                (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
 888        struct ocfs2_refcount_rec *rec = NULL;
 889
 890        for (; i < le16_to_cpu(rb->rf_records.rl_used); i++) {
 891                rec = &rb->rf_records.rl_recs[i];
 892
 893                if (le64_to_cpu(rec->r_cpos) +
 894                    le32_to_cpu(rec->r_clusters) <= cpos)
 895                        continue;
 896                else if (le64_to_cpu(rec->r_cpos) > cpos)
 897                        break;
 898
 899                /* ok, cpos fail in this rec. Just return. */
 900                if (ret_rec)
 901                        *ret_rec = *rec;
 902                goto out;
 903        }
 904
 905        if (ret_rec) {
 906                /* We meet with a hole here, so fake the rec. */
 907                ret_rec->r_cpos = cpu_to_le64(cpos);
 908                ret_rec->r_refcount = 0;
 909                if (i < le16_to_cpu(rb->rf_records.rl_used) &&
 910                    le64_to_cpu(rec->r_cpos) < cpos + len)
 911                        ret_rec->r_clusters =
 912                                cpu_to_le32(le64_to_cpu(rec->r_cpos) - cpos);
 913                else
 914                        ret_rec->r_clusters = cpu_to_le32(len);
 915        }
 916
 917out:
 918        *index = i;
 919}
 920
 921/*
 922 * Try to remove refcount tree. The mechanism is:
 923 * 1) Check whether i_clusters == 0, if no, exit.
 924 * 2) check whether we have i_xattr_loc in dinode. if yes, exit.
 925 * 3) Check whether we have inline xattr stored outside, if yes, exit.
 926 * 4) Remove the tree.
 927 */
 928int ocfs2_try_remove_refcount_tree(struct inode *inode,
 929                                   struct buffer_head *di_bh)
 930{
 931        int ret;
 932        struct ocfs2_inode_info *oi = OCFS2_I(inode);
 933        struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
 934
 935        down_write(&oi->ip_xattr_sem);
 936        down_write(&oi->ip_alloc_sem);
 937
 938        if (oi->ip_clusters)
 939                goto out;
 940
 941        if ((oi->ip_dyn_features & OCFS2_HAS_XATTR_FL) && di->i_xattr_loc)
 942                goto out;
 943
 944        if (oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL &&
 945            ocfs2_has_inline_xattr_value_outside(inode, di))
 946                goto out;
 947
 948        ret = ocfs2_remove_refcount_tree(inode, di_bh);
 949        if (ret)
 950                mlog_errno(ret);
 951out:
 952        up_write(&oi->ip_alloc_sem);
 953        up_write(&oi->ip_xattr_sem);
 954        return 0;
 955}
 956
 957/*
 958 * Find the end range for a leaf refcount block indicated by
 959 * el->l_recs[index].e_blkno.
 960 */
 961static int ocfs2_get_refcount_cpos_end(struct ocfs2_caching_info *ci,
 962                                       struct buffer_head *ref_root_bh,
 963                                       struct ocfs2_extent_block *eb,
 964                                       struct ocfs2_extent_list *el,
 965                                       int index,  u32 *cpos_end)
 966{
 967        int ret, i, subtree_root;
 968        u32 cpos;
 969        u64 blkno;
 970        struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
 971        struct ocfs2_path *left_path = NULL, *right_path = NULL;
 972        struct ocfs2_extent_tree et;
 973        struct ocfs2_extent_list *tmp_el;
 974
 975        if (index < le16_to_cpu(el->l_next_free_rec) - 1) {
 976                /*
 977                 * We have a extent rec after index, so just use the e_cpos
 978                 * of the next extent rec.
 979                 */
 980                *cpos_end = le32_to_cpu(el->l_recs[index+1].e_cpos);
 981                return 0;
 982        }
 983
 984        if (!eb || (eb && !eb->h_next_leaf_blk)) {
 985                /*
 986                 * We are the last extent rec, so any high cpos should
 987                 * be stored in this leaf refcount block.
 988                 */
 989                *cpos_end = UINT_MAX;
 990                return 0;
 991        }
 992
 993        /*
 994         * If the extent block isn't the last one, we have to find
 995         * the subtree root between this extent block and the next
 996         * leaf extent block and get the corresponding e_cpos from
 997         * the subroot. Otherwise we may corrupt the b-tree.
 998         */
 999        ocfs2_init_refcount_extent_tree(&et, ci, ref_root_bh);
1000
1001        left_path = ocfs2_new_path_from_et(&et);
1002        if (!left_path) {
1003                ret = -ENOMEM;
1004                mlog_errno(ret);
1005                goto out;
1006        }
1007
1008        cpos = le32_to_cpu(eb->h_list.l_recs[index].e_cpos);
1009        ret = ocfs2_find_path(ci, left_path, cpos);
1010        if (ret) {
1011                mlog_errno(ret);
1012                goto out;
1013        }
1014
1015        right_path = ocfs2_new_path_from_path(left_path);
1016        if (!right_path) {
1017                ret = -ENOMEM;
1018                mlog_errno(ret);
1019                goto out;
1020        }
1021
1022        ret = ocfs2_find_cpos_for_right_leaf(sb, left_path, &cpos);
1023        if (ret) {
1024                mlog_errno(ret);
1025                goto out;
1026        }
1027
1028        ret = ocfs2_find_path(ci, right_path, cpos);
1029        if (ret) {
1030                mlog_errno(ret);
1031                goto out;
1032        }
1033
1034        subtree_root = ocfs2_find_subtree_root(&et, left_path,
1035                                               right_path);
1036
1037        tmp_el = left_path->p_node[subtree_root].el;
1038        blkno = left_path->p_node[subtree_root+1].bh->b_blocknr;
1039        for (i = 0; i < le16_to_cpu(tmp_el->l_next_free_rec); i++) {
1040                if (le64_to_cpu(tmp_el->l_recs[i].e_blkno) == blkno) {
1041                        *cpos_end = le32_to_cpu(tmp_el->l_recs[i+1].e_cpos);
1042                        break;
1043                }
1044        }
1045
1046        BUG_ON(i == le16_to_cpu(tmp_el->l_next_free_rec));
1047
1048out:
1049        ocfs2_free_path(left_path);
1050        ocfs2_free_path(right_path);
1051        return ret;
1052}
1053
1054/*
1055 * Given a cpos and len, try to find the refcount record which contains cpos.
1056 * 1. If cpos can be found in one refcount record, return the record.
1057 * 2. If cpos can't be found, return a fake record which start from cpos
1058 *    and end at a small value between cpos+len and start of the next record.
1059 *    This fake record has r_refcount = 0.
1060 */
1061static int ocfs2_get_refcount_rec(struct ocfs2_caching_info *ci,
1062                                  struct buffer_head *ref_root_bh,
1063                                  u64 cpos, unsigned int len,
1064                                  struct ocfs2_refcount_rec *ret_rec,
1065                                  int *index,
1066                                  struct buffer_head **ret_bh)
1067{
1068        int ret = 0, i, found;
1069        u32 low_cpos, uninitialized_var(cpos_end);
1070        struct ocfs2_extent_list *el;
1071        struct ocfs2_extent_rec *rec = NULL;
1072        struct ocfs2_extent_block *eb = NULL;
1073        struct buffer_head *eb_bh = NULL, *ref_leaf_bh = NULL;
1074        struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
1075        struct ocfs2_refcount_block *rb =
1076                        (struct ocfs2_refcount_block *)ref_root_bh->b_data;
1077
1078        if (!(le32_to_cpu(rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL)) {
1079                ocfs2_find_refcount_rec_in_rl(ci, ref_root_bh, cpos, len,
1080                                              ret_rec, index);
1081                *ret_bh = ref_root_bh;
1082                get_bh(ref_root_bh);
1083                return 0;
1084        }
1085
1086        el = &rb->rf_list;
1087        low_cpos = cpos & OCFS2_32BIT_POS_MASK;
1088
1089        if (el->l_tree_depth) {
1090                ret = ocfs2_find_leaf(ci, el, low_cpos, &eb_bh);
1091                if (ret) {
1092                        mlog_errno(ret);
1093                        goto out;
1094                }
1095
1096                eb = (struct ocfs2_extent_block *) eb_bh->b_data;
1097                el = &eb->h_list;
1098
1099                if (el->l_tree_depth) {
1100                        ocfs2_error(sb,
1101                        "refcount tree %llu has non zero tree "
1102                        "depth in leaf btree tree block %llu\n",
1103                        (unsigned long long)ocfs2_metadata_cache_owner(ci),
1104                        (unsigned long long)eb_bh->b_blocknr);
1105                        ret = -EROFS;
1106                        goto out;
1107                }
1108        }
1109
1110        found = 0;
1111        for (i = le16_to_cpu(el->l_next_free_rec) - 1; i >= 0; i--) {
1112                rec = &el->l_recs[i];
1113
1114                if (le32_to_cpu(rec->e_cpos) <= low_cpos) {
1115                        found = 1;
1116                        break;
1117                }
1118        }
1119
1120        if (found) {
1121                ret = ocfs2_get_refcount_cpos_end(ci, ref_root_bh,
1122                                                  eb, el, i, &cpos_end);
1123                if (ret) {
1124                        mlog_errno(ret);
1125                        goto out;
1126                }
1127
1128                if (cpos_end < low_cpos + len)
1129                        len = cpos_end - low_cpos;
1130        }
1131
1132        ret = ocfs2_read_refcount_block(ci, le64_to_cpu(rec->e_blkno),
1133                                        &ref_leaf_bh);
1134        if (ret) {
1135                mlog_errno(ret);
1136                goto out;
1137        }
1138
1139        ocfs2_find_refcount_rec_in_rl(ci, ref_leaf_bh, cpos, len,
1140                                      ret_rec, index);
1141        *ret_bh = ref_leaf_bh;
1142out:
1143        brelse(eb_bh);
1144        return ret;
1145}
1146
1147enum ocfs2_ref_rec_contig {
1148        REF_CONTIG_NONE = 0,
1149        REF_CONTIG_LEFT,
1150        REF_CONTIG_RIGHT,
1151        REF_CONTIG_LEFTRIGHT,
1152};
1153
1154static enum ocfs2_ref_rec_contig
1155        ocfs2_refcount_rec_adjacent(struct ocfs2_refcount_block *rb,
1156                                    int index)
1157{
1158        if ((rb->rf_records.rl_recs[index].r_refcount ==
1159            rb->rf_records.rl_recs[index + 1].r_refcount) &&
1160            (le64_to_cpu(rb->rf_records.rl_recs[index].r_cpos) +
1161            le32_to_cpu(rb->rf_records.rl_recs[index].r_clusters) ==
1162            le64_to_cpu(rb->rf_records.rl_recs[index + 1].r_cpos)))
1163                return REF_CONTIG_RIGHT;
1164
1165        return REF_CONTIG_NONE;
1166}
1167
1168static enum ocfs2_ref_rec_contig
1169        ocfs2_refcount_rec_contig(struct ocfs2_refcount_block *rb,
1170                                  int index)
1171{
1172        enum ocfs2_ref_rec_contig ret = REF_CONTIG_NONE;
1173
1174        if (index < le16_to_cpu(rb->rf_records.rl_used) - 1)
1175                ret = ocfs2_refcount_rec_adjacent(rb, index);
1176
1177        if (index > 0) {
1178                enum ocfs2_ref_rec_contig tmp;
1179
1180                tmp = ocfs2_refcount_rec_adjacent(rb, index - 1);
1181
1182                if (tmp == REF_CONTIG_RIGHT) {
1183                        if (ret == REF_CONTIG_RIGHT)
1184                                ret = REF_CONTIG_LEFTRIGHT;
1185                        else
1186                                ret = REF_CONTIG_LEFT;
1187                }
1188        }
1189
1190        return ret;
1191}
1192
1193static void ocfs2_rotate_refcount_rec_left(struct ocfs2_refcount_block *rb,
1194                                           int index)
1195{
1196        BUG_ON(rb->rf_records.rl_recs[index].r_refcount !=
1197               rb->rf_records.rl_recs[index+1].r_refcount);
1198
1199        le32_add_cpu(&rb->rf_records.rl_recs[index].r_clusters,
1200                     le32_to_cpu(rb->rf_records.rl_recs[index+1].r_clusters));
1201
1202        if (index < le16_to_cpu(rb->rf_records.rl_used) - 2)
1203                memmove(&rb->rf_records.rl_recs[index + 1],
1204                        &rb->rf_records.rl_recs[index + 2],
1205                        sizeof(struct ocfs2_refcount_rec) *
1206                        (le16_to_cpu(rb->rf_records.rl_used) - index - 2));
1207
1208        memset(&rb->rf_records.rl_recs[le16_to_cpu(rb->rf_records.rl_used) - 1],
1209               0, sizeof(struct ocfs2_refcount_rec));
1210        le16_add_cpu(&rb->rf_records.rl_used, -1);
1211}
1212
1213/*
1214 * Merge the refcount rec if we are contiguous with the adjacent recs.
1215 */
1216static void ocfs2_refcount_rec_merge(struct ocfs2_refcount_block *rb,
1217                                     int index)
1218{
1219        enum ocfs2_ref_rec_contig contig =
1220                                ocfs2_refcount_rec_contig(rb, index);
1221
1222        if (contig == REF_CONTIG_NONE)
1223                return;
1224
1225        if (contig == REF_CONTIG_LEFT || contig == REF_CONTIG_LEFTRIGHT) {
1226                BUG_ON(index == 0);
1227                index--;
1228        }
1229
1230        ocfs2_rotate_refcount_rec_left(rb, index);
1231
1232        if (contig == REF_CONTIG_LEFTRIGHT)
1233                ocfs2_rotate_refcount_rec_left(rb, index);
1234}
1235
1236/*
1237 * Change the refcount indexed by "index" in ref_bh.
1238 * If refcount reaches 0, remove it.
1239 */
1240static int ocfs2_change_refcount_rec(handle_t *handle,
1241                                     struct ocfs2_caching_info *ci,
1242                                     struct buffer_head *ref_leaf_bh,
1243                                     int index, int merge, int change)
1244{
1245        int ret;
1246        struct ocfs2_refcount_block *rb =
1247                        (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
1248        struct ocfs2_refcount_list *rl = &rb->rf_records;
1249        struct ocfs2_refcount_rec *rec = &rl->rl_recs[index];
1250
1251        ret = ocfs2_journal_access_rb(handle, ci, ref_leaf_bh,
1252                                      OCFS2_JOURNAL_ACCESS_WRITE);
1253        if (ret) {
1254                mlog_errno(ret);
1255                goto out;
1256        }
1257
1258        trace_ocfs2_change_refcount_rec(
1259                (unsigned long long)ocfs2_metadata_cache_owner(ci),
1260                index, le32_to_cpu(rec->r_refcount), change);
1261        le32_add_cpu(&rec->r_refcount, change);
1262
1263        if (!rec->r_refcount) {
1264                if (index != le16_to_cpu(rl->rl_used) - 1) {
1265                        memmove(rec, rec + 1,
1266                                (le16_to_cpu(rl->rl_used) - index - 1) *
1267                                sizeof(struct ocfs2_refcount_rec));
1268                        memset(&rl->rl_recs[le16_to_cpu(rl->rl_used) - 1],
1269                               0, sizeof(struct ocfs2_refcount_rec));
1270                }
1271
1272                le16_add_cpu(&rl->rl_used, -1);
1273        } else if (merge)
1274                ocfs2_refcount_rec_merge(rb, index);
1275
1276        ocfs2_journal_dirty(handle, ref_leaf_bh);
1277out:
1278        return ret;
1279}
1280
1281static int ocfs2_expand_inline_ref_root(handle_t *handle,
1282                                        struct ocfs2_caching_info *ci,
1283                                        struct buffer_head *ref_root_bh,
1284                                        struct buffer_head **ref_leaf_bh,
1285                                        struct ocfs2_alloc_context *meta_ac)
1286{
1287        int ret;
1288        u16 suballoc_bit_start;
1289        u32 num_got;
1290        u64 suballoc_loc, blkno;
1291        struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
1292        struct buffer_head *new_bh = NULL;
1293        struct ocfs2_refcount_block *new_rb;
1294        struct ocfs2_refcount_block *root_rb =
1295                        (struct ocfs2_refcount_block *)ref_root_bh->b_data;
1296
1297        ret = ocfs2_journal_access_rb(handle, ci, ref_root_bh,
1298                                      OCFS2_JOURNAL_ACCESS_WRITE);
1299        if (ret) {
1300                mlog_errno(ret);
1301                goto out;
1302        }
1303
1304        ret = ocfs2_claim_metadata(handle, meta_ac, 1, &suballoc_loc,
1305                                   &suballoc_bit_start, &num_got,
1306                                   &blkno);
1307        if (ret) {
1308                mlog_errno(ret);
1309                goto out;
1310        }
1311
1312        new_bh = sb_getblk(sb, blkno);
1313        if (new_bh == NULL) {
1314                ret = -EIO;
1315                mlog_errno(ret);
1316                goto out;
1317        }
1318        ocfs2_set_new_buffer_uptodate(ci, new_bh);
1319
1320        ret = ocfs2_journal_access_rb(handle, ci, new_bh,
1321                                      OCFS2_JOURNAL_ACCESS_CREATE);
1322        if (ret) {
1323                mlog_errno(ret);
1324                goto out;
1325        }
1326
1327        /*
1328         * Initialize ocfs2_refcount_block.
1329         * It should contain the same information as the old root.
1330         * so just memcpy it and change the corresponding field.
1331         */
1332        memcpy(new_bh->b_data, ref_root_bh->b_data, sb->s_blocksize);
1333
1334        new_rb = (struct ocfs2_refcount_block *)new_bh->b_data;
1335        new_rb->rf_suballoc_slot = cpu_to_le16(meta_ac->ac_alloc_slot);
1336        new_rb->rf_suballoc_loc = cpu_to_le64(suballoc_loc);
1337        new_rb->rf_suballoc_bit = cpu_to_le16(suballoc_bit_start);
1338        new_rb->rf_blkno = cpu_to_le64(blkno);
1339        new_rb->rf_cpos = cpu_to_le32(0);
1340        new_rb->rf_parent = cpu_to_le64(ref_root_bh->b_blocknr);
1341        new_rb->rf_flags = cpu_to_le32(OCFS2_REFCOUNT_LEAF_FL);
1342        ocfs2_journal_dirty(handle, new_bh);
1343
1344        /* Now change the root. */
1345        memset(&root_rb->rf_list, 0, sb->s_blocksize -
1346               offsetof(struct ocfs2_refcount_block, rf_list));
1347        root_rb->rf_list.l_count = cpu_to_le16(ocfs2_extent_recs_per_rb(sb));
1348        root_rb->rf_clusters = cpu_to_le32(1);
1349        root_rb->rf_list.l_next_free_rec = cpu_to_le16(1);
1350        root_rb->rf_list.l_recs[0].e_blkno = cpu_to_le64(blkno);
1351        root_rb->rf_list.l_recs[0].e_leaf_clusters = cpu_to_le16(1);
1352        root_rb->rf_flags = cpu_to_le32(OCFS2_REFCOUNT_TREE_FL);
1353
1354        ocfs2_journal_dirty(handle, ref_root_bh);
1355
1356        trace_ocfs2_expand_inline_ref_root((unsigned long long)blkno,
1357                le16_to_cpu(new_rb->rf_records.rl_used));
1358
1359        *ref_leaf_bh = new_bh;
1360        new_bh = NULL;
1361out:
1362        brelse(new_bh);
1363        return ret;
1364}
1365
1366static int ocfs2_refcount_rec_no_intersect(struct ocfs2_refcount_rec *prev,
1367                                           struct ocfs2_refcount_rec *next)
1368{
1369        if (ocfs2_get_ref_rec_low_cpos(prev) + le32_to_cpu(prev->r_clusters) <=
1370                ocfs2_get_ref_rec_low_cpos(next))
1371                return 1;
1372
1373        return 0;
1374}
1375
1376static int cmp_refcount_rec_by_low_cpos(const void *a, const void *b)
1377{
1378        const struct ocfs2_refcount_rec *l = a, *r = b;
1379        u32 l_cpos = ocfs2_get_ref_rec_low_cpos(l);
1380        u32 r_cpos = ocfs2_get_ref_rec_low_cpos(r);
1381
1382        if (l_cpos > r_cpos)
1383                return 1;
1384        if (l_cpos < r_cpos)
1385                return -1;
1386        return 0;
1387}
1388
1389static int cmp_refcount_rec_by_cpos(const void *a, const void *b)
1390{
1391        const struct ocfs2_refcount_rec *l = a, *r = b;
1392        u64 l_cpos = le64_to_cpu(l->r_cpos);
1393        u64 r_cpos = le64_to_cpu(r->r_cpos);
1394
1395        if (l_cpos > r_cpos)
1396                return 1;
1397        if (l_cpos < r_cpos)
1398                return -1;
1399        return 0;
1400}
1401
1402static void swap_refcount_rec(void *a, void *b, int size)
1403{
1404        struct ocfs2_refcount_rec *l = a, *r = b, tmp;
1405
1406        tmp = *(struct ocfs2_refcount_rec *)l;
1407        *(struct ocfs2_refcount_rec *)l =
1408                        *(struct ocfs2_refcount_rec *)r;
1409        *(struct ocfs2_refcount_rec *)r = tmp;
1410}
1411
1412/*
1413 * The refcount cpos are ordered by their 64bit cpos,
1414 * But we will use the low 32 bit to be the e_cpos in the b-tree.
1415 * So we need to make sure that this pos isn't intersected with others.
1416 *
1417 * Note: The refcount block is already sorted by their low 32 bit cpos,
1418 *       So just try the middle pos first, and we will exit when we find
1419 *       the good position.
1420 */
1421static int ocfs2_find_refcount_split_pos(struct ocfs2_refcount_list *rl,
1422                                         u32 *split_pos, int *split_index)
1423{
1424        int num_used = le16_to_cpu(rl->rl_used);
1425        int delta, middle = num_used / 2;
1426
1427        for (delta = 0; delta < middle; delta++) {
1428                /* Let's check delta earlier than middle */
1429                if (ocfs2_refcount_rec_no_intersect(
1430                                        &rl->rl_recs[middle - delta - 1],
1431                                        &rl->rl_recs[middle - delta])) {
1432                        *split_index = middle - delta;
1433                        break;
1434                }
1435
1436                /* For even counts, don't walk off the end */
1437                if ((middle + delta + 1) == num_used)
1438                        continue;
1439
1440                /* Now try delta past middle */
1441                if (ocfs2_refcount_rec_no_intersect(
1442                                        &rl->rl_recs[middle + delta],
1443                                        &rl->rl_recs[middle + delta + 1])) {
1444                        *split_index = middle + delta + 1;
1445                        break;
1446                }
1447        }
1448
1449        if (delta >= middle)
1450                return -ENOSPC;
1451
1452        *split_pos = ocfs2_get_ref_rec_low_cpos(&rl->rl_recs[*split_index]);
1453        return 0;
1454}
1455
1456static int ocfs2_divide_leaf_refcount_block(struct buffer_head *ref_leaf_bh,
1457                                            struct buffer_head *new_bh,
1458                                            u32 *split_cpos)
1459{
1460        int split_index = 0, num_moved, ret;
1461        u32 cpos = 0;
1462        struct ocfs2_refcount_block *rb =
1463                        (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
1464        struct ocfs2_refcount_list *rl = &rb->rf_records;
1465        struct ocfs2_refcount_block *new_rb =
1466                        (struct ocfs2_refcount_block *)new_bh->b_data;
1467        struct ocfs2_refcount_list *new_rl = &new_rb->rf_records;
1468
1469        trace_ocfs2_divide_leaf_refcount_block(
1470                (unsigned long long)ref_leaf_bh->b_blocknr,
1471                le16_to_cpu(rl->rl_count), le16_to_cpu(rl->rl_used));
1472
1473        /*
1474         * XXX: Improvement later.
1475         * If we know all the high 32 bit cpos is the same, no need to sort.
1476         *
1477         * In order to make the whole process safe, we do:
1478         * 1. sort the entries by their low 32 bit cpos first so that we can
1479         *    find the split cpos easily.
1480         * 2. call ocfs2_insert_extent to insert the new refcount block.
1481         * 3. move the refcount rec to the new block.
1482         * 4. sort the entries by their 64 bit cpos.
1483         * 5. dirty the new_rb and rb.
1484         */
1485        sort(&rl->rl_recs, le16_to_cpu(rl->rl_used),
1486             sizeof(struct ocfs2_refcount_rec),
1487             cmp_refcount_rec_by_low_cpos, swap_refcount_rec);
1488
1489        ret = ocfs2_find_refcount_split_pos(rl, &cpos, &split_index);
1490        if (ret) {
1491                mlog_errno(ret);
1492                return ret;
1493        }
1494
1495        new_rb->rf_cpos = cpu_to_le32(cpos);
1496
1497        /* move refcount records starting from split_index to the new block. */
1498        num_moved = le16_to_cpu(rl->rl_used) - split_index;
1499        memcpy(new_rl->rl_recs, &rl->rl_recs[split_index],
1500               num_moved * sizeof(struct ocfs2_refcount_rec));
1501
1502        /*ok, remove the entries we just moved over to the other block. */
1503        memset(&rl->rl_recs[split_index], 0,
1504               num_moved * sizeof(struct ocfs2_refcount_rec));
1505
1506        /* change old and new rl_used accordingly. */
1507        le16_add_cpu(&rl->rl_used, -num_moved);
1508        new_rl->rl_used = cpu_to_le16(num_moved);
1509
1510        sort(&rl->rl_recs, le16_to_cpu(rl->rl_used),
1511             sizeof(struct ocfs2_refcount_rec),
1512             cmp_refcount_rec_by_cpos, swap_refcount_rec);
1513
1514        sort(&new_rl->rl_recs, le16_to_cpu(new_rl->rl_used),
1515             sizeof(struct ocfs2_refcount_rec),
1516             cmp_refcount_rec_by_cpos, swap_refcount_rec);
1517
1518        *split_cpos = cpos;
1519        return 0;
1520}
1521
1522static int ocfs2_new_leaf_refcount_block(handle_t *handle,
1523                                         struct ocfs2_caching_info *ci,
1524                                         struct buffer_head *ref_root_bh,
1525                                         struct buffer_head *ref_leaf_bh,
1526                                         struct ocfs2_alloc_context *meta_ac)
1527{
1528        int ret;
1529        u16 suballoc_bit_start;
1530        u32 num_got, new_cpos;
1531        u64 suballoc_loc, blkno;
1532        struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
1533        struct ocfs2_refcount_block *root_rb =
1534                        (struct ocfs2_refcount_block *)ref_root_bh->b_data;
1535        struct buffer_head *new_bh = NULL;
1536        struct ocfs2_refcount_block *new_rb;
1537        struct ocfs2_extent_tree ref_et;
1538
1539        BUG_ON(!(le32_to_cpu(root_rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL));
1540
1541        ret = ocfs2_journal_access_rb(handle, ci, ref_root_bh,
1542                                      OCFS2_JOURNAL_ACCESS_WRITE);
1543        if (ret) {
1544                mlog_errno(ret);
1545                goto out;
1546        }
1547
1548        ret = ocfs2_journal_access_rb(handle, ci, ref_leaf_bh,
1549                                      OCFS2_JOURNAL_ACCESS_WRITE);
1550        if (ret) {
1551                mlog_errno(ret);
1552                goto out;
1553        }
1554
1555        ret = ocfs2_claim_metadata(handle, meta_ac, 1, &suballoc_loc,
1556                                   &suballoc_bit_start, &num_got,
1557                                   &blkno);
1558        if (ret) {
1559                mlog_errno(ret);
1560                goto out;
1561        }
1562
1563        new_bh = sb_getblk(sb, blkno);
1564        if (new_bh == NULL) {
1565                ret = -EIO;
1566                mlog_errno(ret);
1567                goto out;
1568        }
1569        ocfs2_set_new_buffer_uptodate(ci, new_bh);
1570
1571        ret = ocfs2_journal_access_rb(handle, ci, new_bh,
1572                                      OCFS2_JOURNAL_ACCESS_CREATE);
1573        if (ret) {
1574                mlog_errno(ret);
1575                goto out;
1576        }
1577
1578        /* Initialize ocfs2_refcount_block. */
1579        new_rb = (struct ocfs2_refcount_block *)new_bh->b_data;
1580        memset(new_rb, 0, sb->s_blocksize);
1581        strcpy((void *)new_rb, OCFS2_REFCOUNT_BLOCK_SIGNATURE);
1582        new_rb->rf_suballoc_slot = cpu_to_le16(meta_ac->ac_alloc_slot);
1583        new_rb->rf_suballoc_loc = cpu_to_le64(suballoc_loc);
1584        new_rb->rf_suballoc_bit = cpu_to_le16(suballoc_bit_start);
1585        new_rb->rf_fs_generation = cpu_to_le32(OCFS2_SB(sb)->fs_generation);
1586        new_rb->rf_blkno = cpu_to_le64(blkno);
1587        new_rb->rf_parent = cpu_to_le64(ref_root_bh->b_blocknr);
1588        new_rb->rf_flags = cpu_to_le32(OCFS2_REFCOUNT_LEAF_FL);
1589        new_rb->rf_records.rl_count =
1590                                cpu_to_le16(ocfs2_refcount_recs_per_rb(sb));
1591        new_rb->rf_generation = root_rb->rf_generation;
1592
1593        ret = ocfs2_divide_leaf_refcount_block(ref_leaf_bh, new_bh, &new_cpos);
1594        if (ret) {
1595                mlog_errno(ret);
1596                goto out;
1597        }
1598
1599        ocfs2_journal_dirty(handle, ref_leaf_bh);
1600        ocfs2_journal_dirty(handle, new_bh);
1601
1602        ocfs2_init_refcount_extent_tree(&ref_et, ci, ref_root_bh);
1603
1604        trace_ocfs2_new_leaf_refcount_block(
1605                        (unsigned long long)new_bh->b_blocknr, new_cpos);
1606
1607        /* Insert the new leaf block with the specific offset cpos. */
1608        ret = ocfs2_insert_extent(handle, &ref_et, new_cpos, new_bh->b_blocknr,
1609                                  1, 0, meta_ac);
1610        if (ret)
1611                mlog_errno(ret);
1612
1613out:
1614        brelse(new_bh);
1615        return ret;
1616}
1617
1618static int ocfs2_expand_refcount_tree(handle_t *handle,
1619                                      struct ocfs2_caching_info *ci,
1620                                      struct buffer_head *ref_root_bh,
1621                                      struct buffer_head *ref_leaf_bh,
1622                                      struct ocfs2_alloc_context *meta_ac)
1623{
1624        int ret;
1625        struct buffer_head *expand_bh = NULL;
1626
1627        if (ref_root_bh == ref_leaf_bh) {
1628                /*
1629                 * the old root bh hasn't been expanded to a b-tree,
1630                 * so expand it first.
1631                 */
1632                ret = ocfs2_expand_inline_ref_root(handle, ci, ref_root_bh,
1633                                                   &expand_bh, meta_ac);
1634                if (ret) {
1635                        mlog_errno(ret);
1636                        goto out;
1637                }
1638        } else {
1639                expand_bh = ref_leaf_bh;
1640                get_bh(expand_bh);
1641        }
1642
1643
1644        /* Now add a new refcount block into the tree.*/
1645        ret = ocfs2_new_leaf_refcount_block(handle, ci, ref_root_bh,
1646                                            expand_bh, meta_ac);
1647        if (ret)
1648                mlog_errno(ret);
1649out:
1650        brelse(expand_bh);
1651        return ret;
1652}
1653
1654/*
1655 * Adjust the extent rec in b-tree representing ref_leaf_bh.
1656 *
1657 * Only called when we have inserted a new refcount rec at index 0
1658 * which means ocfs2_extent_rec.e_cpos may need some change.
1659 */
1660static int ocfs2_adjust_refcount_rec(handle_t *handle,
1661                                     struct ocfs2_caching_info *ci,
1662                                     struct buffer_head *ref_root_bh,
1663                                     struct buffer_head *ref_leaf_bh,
1664                                     struct ocfs2_refcount_rec *rec)
1665{
1666        int ret = 0, i;
1667        u32 new_cpos, old_cpos;
1668        struct ocfs2_path *path = NULL;
1669        struct ocfs2_extent_tree et;
1670        struct ocfs2_refcount_block *rb =
1671                (struct ocfs2_refcount_block *)ref_root_bh->b_data;
1672        struct ocfs2_extent_list *el;
1673
1674        if (!(le32_to_cpu(rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL))
1675                goto out;
1676
1677        rb = (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
1678        old_cpos = le32_to_cpu(rb->rf_cpos);
1679        new_cpos = le64_to_cpu(rec->r_cpos) & OCFS2_32BIT_POS_MASK;
1680        if (old_cpos <= new_cpos)
1681                goto out;
1682
1683        ocfs2_init_refcount_extent_tree(&et, ci, ref_root_bh);
1684
1685        path = ocfs2_new_path_from_et(&et);
1686        if (!path) {
1687                ret = -ENOMEM;
1688                mlog_errno(ret);
1689                goto out;
1690        }
1691
1692        ret = ocfs2_find_path(ci, path, old_cpos);
1693        if (ret) {
1694                mlog_errno(ret);
1695                goto out;
1696        }
1697
1698        /*
1699         * 2 more credits, one for the leaf refcount block, one for
1700         * the extent block contains the extent rec.
1701         */
1702        ret = ocfs2_extend_trans(handle, 2);
1703        if (ret < 0) {
1704                mlog_errno(ret);
1705                goto out;
1706        }
1707
1708        ret = ocfs2_journal_access_rb(handle, ci, ref_leaf_bh,
1709                                      OCFS2_JOURNAL_ACCESS_WRITE);
1710        if (ret < 0) {
1711                mlog_errno(ret);
1712                goto out;
1713        }
1714
1715        ret = ocfs2_journal_access_eb(handle, ci, path_leaf_bh(path),
1716                                      OCFS2_JOURNAL_ACCESS_WRITE);
1717        if (ret < 0) {
1718                mlog_errno(ret);
1719                goto out;
1720        }
1721
1722        /* change the leaf extent block first. */
1723        el = path_leaf_el(path);
1724
1725        for (i = 0; i < le16_to_cpu(el->l_next_free_rec); i++)
1726                if (le32_to_cpu(el->l_recs[i].e_cpos) == old_cpos)
1727                        break;
1728
1729        BUG_ON(i == le16_to_cpu(el->l_next_free_rec));
1730
1731        el->l_recs[i].e_cpos = cpu_to_le32(new_cpos);
1732
1733        /* change the r_cpos in the leaf block. */
1734        rb->rf_cpos = cpu_to_le32(new_cpos);
1735
1736        ocfs2_journal_dirty(handle, path_leaf_bh(path));
1737        ocfs2_journal_dirty(handle, ref_leaf_bh);
1738
1739out:
1740        ocfs2_free_path(path);
1741        return ret;
1742}
1743
1744static int ocfs2_insert_refcount_rec(handle_t *handle,
1745                                     struct ocfs2_caching_info *ci,
1746                                     struct buffer_head *ref_root_bh,
1747                                     struct buffer_head *ref_leaf_bh,
1748                                     struct ocfs2_refcount_rec *rec,
1749                                     int index, int merge,
1750                                     struct ocfs2_alloc_context *meta_ac)
1751{
1752        int ret;
1753        struct ocfs2_refcount_block *rb =
1754                        (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
1755        struct ocfs2_refcount_list *rf_list = &rb->rf_records;
1756        struct buffer_head *new_bh = NULL;
1757
1758        BUG_ON(le32_to_cpu(rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL);
1759
1760        if (rf_list->rl_used == rf_list->rl_count) {
1761                u64 cpos = le64_to_cpu(rec->r_cpos);
1762                u32 len = le32_to_cpu(rec->r_clusters);
1763
1764                ret = ocfs2_expand_refcount_tree(handle, ci, ref_root_bh,
1765                                                 ref_leaf_bh, meta_ac);
1766                if (ret) {
1767                        mlog_errno(ret);
1768                        goto out;
1769                }
1770
1771                ret = ocfs2_get_refcount_rec(ci, ref_root_bh,
1772                                             cpos, len, NULL, &index,
1773                                             &new_bh);
1774                if (ret) {
1775                        mlog_errno(ret);
1776                        goto out;
1777                }
1778
1779                ref_leaf_bh = new_bh;
1780                rb = (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
1781                rf_list = &rb->rf_records;
1782        }
1783
1784        ret = ocfs2_journal_access_rb(handle, ci, ref_leaf_bh,
1785                                      OCFS2_JOURNAL_ACCESS_WRITE);
1786        if (ret) {
1787                mlog_errno(ret);
1788                goto out;
1789        }
1790
1791        if (index < le16_to_cpu(rf_list->rl_used))
1792                memmove(&rf_list->rl_recs[index + 1],
1793                        &rf_list->rl_recs[index],
1794                        (le16_to_cpu(rf_list->rl_used) - index) *
1795                         sizeof(struct ocfs2_refcount_rec));
1796
1797        trace_ocfs2_insert_refcount_rec(
1798                (unsigned long long)ref_leaf_bh->b_blocknr, index,
1799                (unsigned long long)le64_to_cpu(rec->r_cpos),
1800                le32_to_cpu(rec->r_clusters), le32_to_cpu(rec->r_refcount));
1801
1802        rf_list->rl_recs[index] = *rec;
1803
1804        le16_add_cpu(&rf_list->rl_used, 1);
1805
1806        if (merge)
1807                ocfs2_refcount_rec_merge(rb, index);
1808
1809        ocfs2_journal_dirty(handle, ref_leaf_bh);
1810
1811        if (index == 0) {
1812                ret = ocfs2_adjust_refcount_rec(handle, ci,
1813                                                ref_root_bh,
1814                                                ref_leaf_bh, rec);
1815                if (ret)
1816                        mlog_errno(ret);
1817        }
1818out:
1819        brelse(new_bh);
1820        return ret;
1821}
1822
1823/*
1824 * Split the refcount_rec indexed by "index" in ref_leaf_bh.
1825 * This is much simple than our b-tree code.
1826 * split_rec is the new refcount rec we want to insert.
1827 * If split_rec->r_refcount > 0, we are changing the refcount(in case we
1828 * increase refcount or decrease a refcount to non-zero).
1829 * If split_rec->r_refcount == 0, we are punching a hole in current refcount
1830 * rec( in case we decrease a refcount to zero).
1831 */
1832static int ocfs2_split_refcount_rec(handle_t *handle,
1833                                    struct ocfs2_caching_info *ci,
1834                                    struct buffer_head *ref_root_bh,
1835                                    struct buffer_head *ref_leaf_bh,
1836                                    struct ocfs2_refcount_rec *split_rec,
1837                                    int index, int merge,
1838                                    struct ocfs2_alloc_context *meta_ac,
1839                                    struct ocfs2_cached_dealloc_ctxt *dealloc)
1840{
1841        int ret, recs_need;
1842        u32 len;
1843        struct ocfs2_refcount_block *rb =
1844                        (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
1845        struct ocfs2_refcount_list *rf_list = &rb->rf_records;
1846        struct ocfs2_refcount_rec *orig_rec = &rf_list->rl_recs[index];
1847        struct ocfs2_refcount_rec *tail_rec = NULL;
1848        struct buffer_head *new_bh = NULL;
1849
1850        BUG_ON(le32_to_cpu(rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL);
1851
1852        trace_ocfs2_split_refcount_rec(le64_to_cpu(orig_rec->r_cpos),
1853                le32_to_cpu(orig_rec->r_clusters),
1854                le32_to_cpu(orig_rec->r_refcount),
1855                le64_to_cpu(split_rec->r_cpos),
1856                le32_to_cpu(split_rec->r_clusters),
1857                le32_to_cpu(split_rec->r_refcount));
1858
1859        /*
1860         * If we just need to split the header or tail clusters,
1861         * no more recs are needed, just split is OK.
1862         * Otherwise we at least need one new recs.
1863         */
1864        if (!split_rec->r_refcount &&
1865            (split_rec->r_cpos == orig_rec->r_cpos ||
1866             le64_to_cpu(split_rec->r_cpos) +
1867             le32_to_cpu(split_rec->r_clusters) ==
1868             le64_to_cpu(orig_rec->r_cpos) + le32_to_cpu(orig_rec->r_clusters)))
1869                recs_need = 0;
1870        else
1871                recs_need = 1;
1872
1873        /*
1874         * We need one more rec if we split in the middle and the new rec have
1875         * some refcount in it.
1876         */
1877        if (split_rec->r_refcount &&
1878            (split_rec->r_cpos != orig_rec->r_cpos &&
1879             le64_to_cpu(split_rec->r_cpos) +
1880             le32_to_cpu(split_rec->r_clusters) !=
1881             le64_to_cpu(orig_rec->r_cpos) + le32_to_cpu(orig_rec->r_clusters)))
1882                recs_need++;
1883
1884        /* If the leaf block don't have enough record, expand it. */
1885        if (le16_to_cpu(rf_list->rl_used) + recs_need >
1886                                         le16_to_cpu(rf_list->rl_count)) {
1887                struct ocfs2_refcount_rec tmp_rec;
1888                u64 cpos = le64_to_cpu(orig_rec->r_cpos);
1889                len = le32_to_cpu(orig_rec->r_clusters);
1890                ret = ocfs2_expand_refcount_tree(handle, ci, ref_root_bh,
1891                                                 ref_leaf_bh, meta_ac);
1892                if (ret) {
1893                        mlog_errno(ret);
1894                        goto out;
1895                }
1896
1897                /*
1898                 * We have to re-get it since now cpos may be moved to
1899                 * another leaf block.
1900                 */
1901                ret = ocfs2_get_refcount_rec(ci, ref_root_bh,
1902                                             cpos, len, &tmp_rec, &index,
1903                                             &new_bh);
1904                if (ret) {
1905                        mlog_errno(ret);
1906                        goto out;
1907                }
1908
1909                ref_leaf_bh = new_bh;
1910                rb = (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
1911                rf_list = &rb->rf_records;
1912                orig_rec = &rf_list->rl_recs[index];
1913        }
1914
1915        ret = ocfs2_journal_access_rb(handle, ci, ref_leaf_bh,
1916                                      OCFS2_JOURNAL_ACCESS_WRITE);
1917        if (ret) {
1918                mlog_errno(ret);
1919                goto out;
1920        }
1921
1922        /*
1923         * We have calculated out how many new records we need and store
1924         * in recs_need, so spare enough space first by moving the records
1925         * after "index" to the end.
1926         */
1927        if (index != le16_to_cpu(rf_list->rl_used) - 1)
1928                memmove(&rf_list->rl_recs[index + 1 + recs_need],
1929                        &rf_list->rl_recs[index + 1],
1930                        (le16_to_cpu(rf_list->rl_used) - index - 1) *
1931                         sizeof(struct ocfs2_refcount_rec));
1932
1933        len = (le64_to_cpu(orig_rec->r_cpos) +
1934              le32_to_cpu(orig_rec->r_clusters)) -
1935              (le64_to_cpu(split_rec->r_cpos) +
1936              le32_to_cpu(split_rec->r_clusters));
1937
1938        /*
1939         * If we have "len", the we will split in the tail and move it
1940         * to the end of the space we have just spared.
1941         */
1942        if (len) {
1943                tail_rec = &rf_list->rl_recs[index + recs_need];
1944
1945                memcpy(tail_rec, orig_rec, sizeof(struct ocfs2_refcount_rec));
1946                le64_add_cpu(&tail_rec->r_cpos,
1947                             le32_to_cpu(tail_rec->r_clusters) - len);
1948                tail_rec->r_clusters = cpu_to_le32(len);
1949        }
1950
1951        /*
1952         * If the split pos isn't the same as the original one, we need to
1953         * split in the head.
1954         *
1955         * Note: We have the chance that split_rec.r_refcount = 0,
1956         * recs_need = 0 and len > 0, which means we just cut the head from
1957         * the orig_rec and in that case we have done some modification in
1958         * orig_rec above, so the check for r_cpos is faked.
1959         */
1960        if (split_rec->r_cpos != orig_rec->r_cpos && tail_rec != orig_rec) {
1961                len = le64_to_cpu(split_rec->r_cpos) -
1962                      le64_to_cpu(orig_rec->r_cpos);
1963                orig_rec->r_clusters = cpu_to_le32(len);
1964                index++;
1965        }
1966
1967        le16_add_cpu(&rf_list->rl_used, recs_need);
1968
1969        if (split_rec->r_refcount) {
1970                rf_list->rl_recs[index] = *split_rec;
1971                trace_ocfs2_split_refcount_rec_insert(
1972                        (unsigned long long)ref_leaf_bh->b_blocknr, index,
1973                        (unsigned long long)le64_to_cpu(split_rec->r_cpos),
1974                        le32_to_cpu(split_rec->r_clusters),
1975                        le32_to_cpu(split_rec->r_refcount));
1976
1977                if (merge)
1978                        ocfs2_refcount_rec_merge(rb, index);
1979        }
1980
1981        ocfs2_journal_dirty(handle, ref_leaf_bh);
1982
1983out:
1984        brelse(new_bh);
1985        return ret;
1986}
1987
1988static int __ocfs2_increase_refcount(handle_t *handle,
1989                                     struct ocfs2_caching_info *ci,
1990                                     struct buffer_head *ref_root_bh,
1991                                     u64 cpos, u32 len, int merge,
1992                                     struct ocfs2_alloc_context *meta_ac,
1993                                     struct ocfs2_cached_dealloc_ctxt *dealloc)
1994{
1995        int ret = 0, index;
1996        struct buffer_head *ref_leaf_bh = NULL;
1997        struct ocfs2_refcount_rec rec;
1998        unsigned int set_len = 0;
1999
2000        trace_ocfs2_increase_refcount_begin(
2001             (unsigned long long)ocfs2_metadata_cache_owner(ci),
2002             (unsigned long long)cpos, len);
2003
2004        while (len) {
2005                ret = ocfs2_get_refcount_rec(ci, ref_root_bh,
2006                                             cpos, len, &rec, &index,
2007                                             &ref_leaf_bh);
2008                if (ret) {
2009                        mlog_errno(ret);
2010                        goto out;
2011                }
2012
2013                set_len = le32_to_cpu(rec.r_clusters);
2014
2015                /*
2016                 * Here we may meet with 3 situations:
2017                 *
2018                 * 1. If we find an already existing record, and the length
2019                 *    is the same, cool, we just need to increase the r_refcount
2020                 *    and it is OK.
2021                 * 2. If we find a hole, just insert it with r_refcount = 1.
2022                 * 3. If we are in the middle of one extent record, split
2023                 *    it.
2024                 */
2025                if (rec.r_refcount && le64_to_cpu(rec.r_cpos) == cpos &&
2026                    set_len <= len) {
2027                        trace_ocfs2_increase_refcount_change(
2028                                (unsigned long long)cpos, set_len,
2029                                le32_to_cpu(rec.r_refcount));
2030                        ret = ocfs2_change_refcount_rec(handle, ci,
2031                                                        ref_leaf_bh, index,
2032                                                        merge, 1);
2033                        if (ret) {
2034                                mlog_errno(ret);
2035                                goto out;
2036                        }
2037                } else if (!rec.r_refcount) {
2038                        rec.r_refcount = cpu_to_le32(1);
2039
2040                        trace_ocfs2_increase_refcount_insert(
2041                             (unsigned long long)le64_to_cpu(rec.r_cpos),
2042                             set_len);
2043                        ret = ocfs2_insert_refcount_rec(handle, ci, ref_root_bh,
2044                                                        ref_leaf_bh,
2045                                                        &rec, index,
2046                                                        merge, meta_ac);
2047                        if (ret) {
2048                                mlog_errno(ret);
2049                                goto out;
2050                        }
2051                } else  {
2052                        set_len = min((u64)(cpos + len),
2053                                      le64_to_cpu(rec.r_cpos) + set_len) - cpos;
2054                        rec.r_cpos = cpu_to_le64(cpos);
2055                        rec.r_clusters = cpu_to_le32(set_len);
2056                        le32_add_cpu(&rec.r_refcount, 1);
2057
2058                        trace_ocfs2_increase_refcount_split(
2059                             (unsigned long long)le64_to_cpu(rec.r_cpos),
2060                             set_len, le32_to_cpu(rec.r_refcount));
2061                        ret = ocfs2_split_refcount_rec(handle, ci,
2062                                                       ref_root_bh, ref_leaf_bh,
2063                                                       &rec, index, merge,
2064                                                       meta_ac, dealloc);
2065                        if (ret) {
2066                                mlog_errno(ret);
2067                                goto out;
2068                        }
2069                }
2070
2071                cpos += set_len;
2072                len -= set_len;
2073                brelse(ref_leaf_bh);
2074                ref_leaf_bh = NULL;
2075        }
2076
2077out:
2078        brelse(ref_leaf_bh);
2079        return ret;
2080}
2081
2082static int ocfs2_remove_refcount_extent(handle_t *handle,
2083                                struct ocfs2_caching_info *ci,
2084                                struct buffer_head *ref_root_bh,
2085                                struct buffer_head *ref_leaf_bh,
2086                                struct ocfs2_alloc_context *meta_ac,
2087                                struct ocfs2_cached_dealloc_ctxt *dealloc)
2088{
2089        int ret;
2090        struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
2091        struct ocfs2_refcount_block *rb =
2092                        (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
2093        struct ocfs2_extent_tree et;
2094
2095        BUG_ON(rb->rf_records.rl_used);
2096
2097        trace_ocfs2_remove_refcount_extent(
2098                (unsigned long long)ocfs2_metadata_cache_owner(ci),
2099                (unsigned long long)ref_leaf_bh->b_blocknr,
2100                le32_to_cpu(rb->rf_cpos));
2101
2102        ocfs2_init_refcount_extent_tree(&et, ci, ref_root_bh);
2103        ret = ocfs2_remove_extent(handle, &et, le32_to_cpu(rb->rf_cpos),
2104                                  1, meta_ac, dealloc);
2105        if (ret) {
2106                mlog_errno(ret);
2107                goto out;
2108        }
2109
2110        ocfs2_remove_from_cache(ci, ref_leaf_bh);
2111
2112        /*
2113         * add the freed block to the dealloc so that it will be freed
2114         * when we run dealloc.
2115         */
2116        ret = ocfs2_cache_block_dealloc(dealloc, EXTENT_ALLOC_SYSTEM_INODE,
2117                                        le16_to_cpu(rb->rf_suballoc_slot),
2118                                        le64_to_cpu(rb->rf_suballoc_loc),
2119                                        le64_to_cpu(rb->rf_blkno),
2120                                        le16_to_cpu(rb->rf_suballoc_bit));
2121        if (ret) {
2122                mlog_errno(ret);
2123                goto out;
2124        }
2125
2126        ret = ocfs2_journal_access_rb(handle, ci, ref_root_bh,
2127                                      OCFS2_JOURNAL_ACCESS_WRITE);
2128        if (ret) {
2129                mlog_errno(ret);
2130                goto out;
2131        }
2132
2133        rb = (struct ocfs2_refcount_block *)ref_root_bh->b_data;
2134
2135        le32_add_cpu(&rb->rf_clusters, -1);
2136
2137        /*
2138         * check whether we need to restore the root refcount block if
2139         * there is no leaf extent block at atll.
2140         */
2141        if (!rb->rf_list.l_next_free_rec) {
2142                BUG_ON(rb->rf_clusters);
2143
2144                trace_ocfs2_restore_refcount_block(
2145                     (unsigned long long)ref_root_bh->b_blocknr);
2146
2147                rb->rf_flags = 0;
2148                rb->rf_parent = 0;
2149                rb->rf_cpos = 0;
2150                memset(&rb->rf_records, 0, sb->s_blocksize -
2151                       offsetof(struct ocfs2_refcount_block, rf_records));
2152                rb->rf_records.rl_count =
2153                                cpu_to_le16(ocfs2_refcount_recs_per_rb(sb));
2154        }
2155
2156        ocfs2_journal_dirty(handle, ref_root_bh);
2157
2158out:
2159        return ret;
2160}
2161
2162int ocfs2_increase_refcount(handle_t *handle,
2163                            struct ocfs2_caching_info *ci,
2164                            struct buffer_head *ref_root_bh,
2165                            u64 cpos, u32 len,
2166                            struct ocfs2_alloc_context *meta_ac,
2167                            struct ocfs2_cached_dealloc_ctxt *dealloc)
2168{
2169        return __ocfs2_increase_refcount(handle, ci, ref_root_bh,
2170                                         cpos, len, 1,
2171                                         meta_ac, dealloc);
2172}
2173
2174static int ocfs2_decrease_refcount_rec(handle_t *handle,
2175                                struct ocfs2_caching_info *ci,
2176                                struct buffer_head *ref_root_bh,
2177                                struct buffer_head *ref_leaf_bh,
2178                                int index, u64 cpos, unsigned int len,
2179                                struct ocfs2_alloc_context *meta_ac,
2180                                struct ocfs2_cached_dealloc_ctxt *dealloc)
2181{
2182        int ret;
2183        struct ocfs2_refcount_block *rb =
2184                        (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
2185        struct ocfs2_refcount_rec *rec = &rb->rf_records.rl_recs[index];
2186
2187        BUG_ON(cpos < le64_to_cpu(rec->r_cpos));
2188        BUG_ON(cpos + len >
2189               le64_to_cpu(rec->r_cpos) + le32_to_cpu(rec->r_clusters));
2190
2191        trace_ocfs2_decrease_refcount_rec(
2192                (unsigned long long)ocfs2_metadata_cache_owner(ci),
2193                (unsigned long long)cpos, len);
2194
2195        if (cpos == le64_to_cpu(rec->r_cpos) &&
2196            len == le32_to_cpu(rec->r_clusters))
2197                ret = ocfs2_change_refcount_rec(handle, ci,
2198                                                ref_leaf_bh, index, 1, -1);
2199        else {
2200                struct ocfs2_refcount_rec split = *rec;
2201                split.r_cpos = cpu_to_le64(cpos);
2202                split.r_clusters = cpu_to_le32(len);
2203
2204                le32_add_cpu(&split.r_refcount, -1);
2205
2206                ret = ocfs2_split_refcount_rec(handle, ci,
2207                                               ref_root_bh, ref_leaf_bh,
2208                                               &split, index, 1,
2209                                               meta_ac, dealloc);
2210        }
2211
2212        if (ret) {
2213                mlog_errno(ret);
2214                goto out;
2215        }
2216
2217        /* Remove the leaf refcount block if it contains no refcount record. */
2218        if (!rb->rf_records.rl_used && ref_leaf_bh != ref_root_bh) {
2219                ret = ocfs2_remove_refcount_extent(handle, ci, ref_root_bh,
2220                                                   ref_leaf_bh, meta_ac,
2221                                                   dealloc);
2222                if (ret)
2223                        mlog_errno(ret);
2224        }
2225
2226out:
2227        return ret;
2228}
2229
2230static int __ocfs2_decrease_refcount(handle_t *handle,
2231                                     struct ocfs2_caching_info *ci,
2232                                     struct buffer_head *ref_root_bh,
2233                                     u64 cpos, u32 len,
2234                                     struct ocfs2_alloc_context *meta_ac,
2235                                     struct ocfs2_cached_dealloc_ctxt *dealloc,
2236                                     int delete)
2237{
2238        int ret = 0, index = 0;
2239        struct ocfs2_refcount_rec rec;
2240        unsigned int r_count = 0, r_len;
2241        struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
2242        struct buffer_head *ref_leaf_bh = NULL;
2243
2244        trace_ocfs2_decrease_refcount(
2245                (unsigned long long)ocfs2_metadata_cache_owner(ci),
2246                (unsigned long long)cpos, len, delete);
2247
2248        while (len) {
2249                ret = ocfs2_get_refcount_rec(ci, ref_root_bh,
2250                                             cpos, len, &rec, &index,
2251                                             &ref_leaf_bh);
2252                if (ret) {
2253                        mlog_errno(ret);
2254                        goto out;
2255                }
2256
2257                r_count = le32_to_cpu(rec.r_refcount);
2258                BUG_ON(r_count == 0);
2259                if (!delete)
2260                        BUG_ON(r_count > 1);
2261
2262                r_len = min((u64)(cpos + len), le64_to_cpu(rec.r_cpos) +
2263                              le32_to_cpu(rec.r_clusters)) - cpos;
2264
2265                ret = ocfs2_decrease_refcount_rec(handle, ci, ref_root_bh,
2266                                                  ref_leaf_bh, index,
2267                                                  cpos, r_len,
2268                                                  meta_ac, dealloc);
2269                if (ret) {
2270                        mlog_errno(ret);
2271                        goto out;
2272                }
2273
2274                if (le32_to_cpu(rec.r_refcount) == 1 && delete) {
2275                        ret = ocfs2_cache_cluster_dealloc(dealloc,
2276                                          ocfs2_clusters_to_blocks(sb, cpos),
2277                                                          r_len);
2278                        if (ret) {
2279                                mlog_errno(ret);
2280                                goto out;
2281                        }
2282                }
2283
2284                cpos += r_len;
2285                len -= r_len;
2286                brelse(ref_leaf_bh);
2287                ref_leaf_bh = NULL;
2288        }
2289
2290out:
2291        brelse(ref_leaf_bh);
2292        return ret;
2293}
2294
2295/* Caller must hold refcount tree lock. */
2296int ocfs2_decrease_refcount(struct inode *inode,
2297                            handle_t *handle, u32 cpos, u32 len,
2298                            struct ocfs2_alloc_context *meta_ac,
2299                            struct ocfs2_cached_dealloc_ctxt *dealloc,
2300                            int delete)
2301{
2302        int ret;
2303        u64 ref_blkno;
2304        struct ocfs2_inode_info *oi = OCFS2_I(inode);
2305        struct buffer_head *ref_root_bh = NULL;
2306        struct ocfs2_refcount_tree *tree;
2307
2308        BUG_ON(!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL));
2309
2310        ret = ocfs2_get_refcount_block(inode, &ref_blkno);
2311        if (ret) {
2312                mlog_errno(ret);
2313                goto out;
2314        }
2315
2316        ret = ocfs2_get_refcount_tree(OCFS2_SB(inode->i_sb), ref_blkno, &tree);
2317        if (ret) {
2318                mlog_errno(ret);
2319                goto out;
2320        }
2321
2322        ret = ocfs2_read_refcount_block(&tree->rf_ci, tree->rf_blkno,
2323                                        &ref_root_bh);
2324        if (ret) {
2325                mlog_errno(ret);
2326                goto out;
2327        }
2328
2329        ret = __ocfs2_decrease_refcount(handle, &tree->rf_ci, ref_root_bh,
2330                                        cpos, len, meta_ac, dealloc, delete);
2331        if (ret)
2332                mlog_errno(ret);
2333out:
2334        brelse(ref_root_bh);
2335        return ret;
2336}
2337
2338/*
2339 * Mark the already-existing extent at cpos as refcounted for len clusters.
2340 * This adds the refcount extent flag.
2341 *
2342 * If the existing extent is larger than the request, initiate a
2343 * split. An attempt will be made at merging with adjacent extents.
2344 *
2345 * The caller is responsible for passing down meta_ac if we'll need it.
2346 */
2347static int ocfs2_mark_extent_refcounted(struct inode *inode,
2348                                struct ocfs2_extent_tree *et,
2349                                handle_t *handle, u32 cpos,
2350                                u32 len, u32 phys,
2351                                struct ocfs2_alloc_context *meta_ac,
2352                                struct ocfs2_cached_dealloc_ctxt *dealloc)
2353{
2354        int ret;
2355
2356        trace_ocfs2_mark_extent_refcounted(OCFS2_I(inode)->ip_blkno,
2357                                           cpos, len, phys);
2358
2359        if (!ocfs2_refcount_tree(OCFS2_SB(inode->i_sb))) {
2360                ocfs2_error(inode->i_sb, "Inode %lu want to use refcount "
2361                            "tree, but the feature bit is not set in the "
2362                            "super block.", inode->i_ino);
2363                ret = -EROFS;
2364                goto out;
2365        }
2366
2367        ret = ocfs2_change_extent_flag(handle, et, cpos,
2368                                       len, phys, meta_ac, dealloc,
2369                                       OCFS2_EXT_REFCOUNTED, 0);
2370        if (ret)
2371                mlog_errno(ret);
2372
2373out:
2374        return ret;
2375}
2376
2377/*
2378 * Given some contiguous physical clusters, calculate what we need
2379 * for modifying their refcount.
2380 */
2381static int ocfs2_calc_refcount_meta_credits(struct super_block *sb,
2382                                            struct ocfs2_caching_info *ci,
2383                                            struct buffer_head *ref_root_bh,
2384                                            u64 start_cpos,
2385                                            u32 clusters,
2386                                            int *meta_add,
2387                                            int *credits)
2388{
2389        int ret = 0, index, ref_blocks = 0, recs_add = 0;
2390        u64 cpos = start_cpos;
2391        struct ocfs2_refcount_block *rb;
2392        struct ocfs2_refcount_rec rec;
2393        struct buffer_head *ref_leaf_bh = NULL, *prev_bh = NULL;
2394        u32 len;
2395
2396        while (clusters) {
2397                ret = ocfs2_get_refcount_rec(ci, ref_root_bh,
2398                                             cpos, clusters, &rec,
2399                                             &index, &ref_leaf_bh);
2400                if (ret) {
2401                        mlog_errno(ret);
2402                        goto out;
2403                }
2404
2405                if (ref_leaf_bh != prev_bh) {
2406                        /*
2407                         * Now we encounter a new leaf block, so calculate
2408                         * whether we need to extend the old leaf.
2409                         */
2410                        if (prev_bh) {
2411                                rb = (struct ocfs2_refcount_block *)
2412                                                        prev_bh->b_data;
2413
2414                                if (le16_to_cpu(rb->rf_records.rl_used) +
2415                                    recs_add >
2416                                    le16_to_cpu(rb->rf_records.rl_count))
2417                                        ref_blocks++;
2418                        }
2419
2420                        recs_add = 0;
2421                        *credits += 1;
2422                        brelse(prev_bh);
2423                        prev_bh = ref_leaf_bh;
2424                        get_bh(prev_bh);
2425                }
2426
2427                rb = (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
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                                                      ref_blocks);
2508        } else {
2509                *credits += OCFS2_EXPAND_REFCOUNT_TREE_CREDITS;
2510                *meta_add += 1;
2511        }
2512
2513out:
2514
2515        trace_ocfs2_calc_refcount_meta_credits(
2516                (unsigned long long)start_cpos, clusters,
2517                *meta_add, *credits);
2518        brelse(ref_leaf_bh);
2519        brelse(prev_bh);
2520        return ret;
2521}
2522
2523/*
2524 * For refcount tree, we will decrease some contiguous clusters
2525 * refcount count, so just go through it to see how many blocks
2526 * we gonna touch and whether we need to create new blocks.
2527 *
2528 * Normally the refcount blocks store these refcount should be
2529 * contiguous also, so that we can get the number easily.
2530 * We will at most add split 2 refcount records and 2 more
2531 * refcount blocks, so just check it in a rough way.
2532 *
2533 * Caller must hold refcount tree lock.
2534 */
2535int ocfs2_prepare_refcount_change_for_del(struct inode *inode,
2536                                          u64 refcount_loc,
2537                                          u64 phys_blkno,
2538                                          u32 clusters,
2539                                          int *credits,
2540                                          int *ref_blocks)
2541{
2542        int ret;
2543        struct ocfs2_inode_info *oi = OCFS2_I(inode);
2544        struct buffer_head *ref_root_bh = NULL;
2545        struct ocfs2_refcount_tree *tree;
2546        u64 start_cpos = ocfs2_blocks_to_clusters(inode->i_sb, phys_blkno);
2547
2548        if (!ocfs2_refcount_tree(OCFS2_SB(inode->i_sb))) {
2549                ocfs2_error(inode->i_sb, "Inode %lu want to use refcount "
2550                            "tree, but the feature bit is not set in the "
2551                            "super block.", inode->i_ino);
2552                ret = -EROFS;
2553                goto out;
2554        }
2555
2556        BUG_ON(!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL));
2557
2558        ret = ocfs2_get_refcount_tree(OCFS2_SB(inode->i_sb),
2559                                      refcount_loc, &tree);
2560        if (ret) {
2561                mlog_errno(ret);
2562                goto out;
2563        }
2564
2565        ret = ocfs2_read_refcount_block(&tree->rf_ci, refcount_loc,
2566                                        &ref_root_bh);
2567        if (ret) {
2568                mlog_errno(ret);
2569                goto out;
2570        }
2571
2572        ret = ocfs2_calc_refcount_meta_credits(inode->i_sb,
2573                                               &tree->rf_ci,
2574                                               ref_root_bh,
2575                                               start_cpos, clusters,
2576                                               ref_blocks, credits);
2577        if (ret) {
2578                mlog_errno(ret);
2579                goto out;
2580        }
2581
2582        trace_ocfs2_prepare_refcount_change_for_del(*ref_blocks, *credits);
2583
2584out:
2585        brelse(ref_root_bh);
2586        return ret;
2587}
2588
2589#define MAX_CONTIG_BYTES        1048576
2590
2591static inline unsigned int ocfs2_cow_contig_clusters(struct super_block *sb)
2592{
2593        return ocfs2_clusters_for_bytes(sb, MAX_CONTIG_BYTES);
2594}
2595
2596static inline unsigned int ocfs2_cow_contig_mask(struct super_block *sb)
2597{
2598        return ~(ocfs2_cow_contig_clusters(sb) - 1);
2599}
2600
2601/*
2602 * Given an extent that starts at 'start' and an I/O that starts at 'cpos',
2603 * find an offset (start + (n * contig_clusters)) that is closest to cpos
2604 * while still being less than or equal to it.
2605 *
2606 * The goal is to break the extent at a multiple of contig_clusters.
2607 */
2608static inline unsigned int ocfs2_cow_align_start(struct super_block *sb,
2609                                                 unsigned int start,
2610                                                 unsigned int cpos)
2611{
2612        BUG_ON(start > cpos);
2613
2614        return start + ((cpos - start) & ocfs2_cow_contig_mask(sb));
2615}
2616
2617/*
2618 * Given a cluster count of len, pad it out so that it is a multiple
2619 * of contig_clusters.
2620 */
2621static inline unsigned int ocfs2_cow_align_length(struct super_block *sb,
2622                                                  unsigned int len)
2623{
2624        unsigned int padded =
2625                (len + (ocfs2_cow_contig_clusters(sb) - 1)) &
2626                ocfs2_cow_contig_mask(sb);
2627
2628        /* Did we wrap? */
2629        if (padded < len)
2630                padded = UINT_MAX;
2631
2632        return padded;
2633}
2634
2635/*
2636 * Calculate out the start and number of virtual clusters we need to to CoW.
2637 *
2638 * cpos is vitual start cluster position we want to do CoW in a
2639 * file and write_len is the cluster length.
2640 * max_cpos is the place where we want to stop CoW intentionally.
2641 *
2642 * Normal we will start CoW from the beginning of extent record cotaining cpos.
2643 * We try to break up extents on boundaries of MAX_CONTIG_BYTES so that we
2644 * get good I/O from the resulting extent tree.
2645 */
2646static int ocfs2_refcount_cal_cow_clusters(struct inode *inode,
2647                                           struct ocfs2_extent_list *el,
2648                                           u32 cpos,
2649                                           u32 write_len,
2650                                           u32 max_cpos,
2651                                           u32 *cow_start,
2652                                           u32 *cow_len)
2653{
2654        int ret = 0;
2655        int tree_height = le16_to_cpu(el->l_tree_depth), i;
2656        struct buffer_head *eb_bh = NULL;
2657        struct ocfs2_extent_block *eb = NULL;
2658        struct ocfs2_extent_rec *rec;
2659        unsigned int want_clusters, rec_end = 0;
2660        int contig_clusters = ocfs2_cow_contig_clusters(inode->i_sb);
2661        int leaf_clusters;
2662
2663        BUG_ON(cpos + write_len > max_cpos);
2664
2665        if (tree_height > 0) {
2666                ret = ocfs2_find_leaf(INODE_CACHE(inode), el, cpos, &eb_bh);
2667                if (ret) {
2668                        mlog_errno(ret);
2669                        goto out;
2670                }
2671
2672                eb = (struct ocfs2_extent_block *) eb_bh->b_data;
2673                el = &eb->h_list;
2674
2675                if (el->l_tree_depth) {
2676                        ocfs2_error(inode->i_sb,
2677                                    "Inode %lu has non zero tree depth in "
2678                                    "leaf block %llu\n", inode->i_ino,
2679                                    (unsigned long long)eb_bh->b_blocknr);
2680                        ret = -EROFS;
2681                        goto out;
2682                }
2683        }
2684
2685        *cow_len = 0;
2686        for (i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
2687                rec = &el->l_recs[i];
2688
2689                if (ocfs2_is_empty_extent(rec)) {
2690                        mlog_bug_on_msg(i != 0, "Inode %lu has empty record in "
2691                                        "index %d\n", inode->i_ino, i);
2692                        continue;
2693                }
2694
2695                if (le32_to_cpu(rec->e_cpos) +
2696                    le16_to_cpu(rec->e_leaf_clusters) <= cpos)
2697                        continue;
2698
2699                if (*cow_len == 0) {
2700                        /*
2701                         * We should find a refcounted record in the
2702                         * first pass.
2703                         */
2704                        BUG_ON(!(rec->e_flags & OCFS2_EXT_REFCOUNTED));
2705                        *cow_start = le32_to_cpu(rec->e_cpos);
2706                }
2707
2708                /*
2709                 * If we encounter a hole, a non-refcounted record or
2710                 * pass the max_cpos, stop the search.
2711                 */
2712                if ((!(rec->e_flags & OCFS2_EXT_REFCOUNTED)) ||
2713                    (*cow_len && rec_end != le32_to_cpu(rec->e_cpos)) ||
2714                    (max_cpos <= le32_to_cpu(rec->e_cpos)))
2715                        break;
2716
2717                leaf_clusters = le16_to_cpu(rec->e_leaf_clusters);
2718                rec_end = le32_to_cpu(rec->e_cpos) + leaf_clusters;
2719                if (rec_end > max_cpos) {
2720                        rec_end = max_cpos;
2721                        leaf_clusters = rec_end - le32_to_cpu(rec->e_cpos);
2722                }
2723
2724                /*
2725                 * How many clusters do we actually need from
2726                 * this extent?  First we see how many we actually
2727                 * need to complete the write.  If that's smaller
2728                 * than contig_clusters, we try for contig_clusters.
2729                 */
2730                if (!*cow_len)
2731                        want_clusters = write_len;
2732                else
2733                        want_clusters = (cpos + write_len) -
2734                                (*cow_start + *cow_len);
2735                if (want_clusters < contig_clusters)
2736                        want_clusters = contig_clusters;
2737
2738                /*
2739                 * If the write does not cover the whole extent, we
2740                 * need to calculate how we're going to split the extent.
2741                 * We try to do it on contig_clusters boundaries.
2742                 *
2743                 * Any extent smaller than contig_clusters will be
2744                 * CoWed in its entirety.
2745                 */
2746                if (leaf_clusters <= contig_clusters)
2747                        *cow_len += leaf_clusters;
2748                else if (*cow_len || (*cow_start == cpos)) {
2749                        /*
2750                         * This extent needs to be CoW'd from its
2751                         * beginning, so all we have to do is compute
2752                         * how many clusters to grab.  We align
2753                         * want_clusters to the edge of contig_clusters
2754                         * to get better I/O.
2755                         */
2756                        want_clusters = ocfs2_cow_align_length(inode->i_sb,
2757                                                               want_clusters);
2758
2759                        if (leaf_clusters < want_clusters)
2760                                *cow_len += leaf_clusters;
2761                        else
2762                                *cow_len += want_clusters;
2763                } else if ((*cow_start + contig_clusters) >=
2764                           (cpos + write_len)) {
2765                        /*
2766                         * Breaking off contig_clusters at the front
2767                         * of the extent will cover our write.  That's
2768                         * easy.
2769                         */
2770                        *cow_len = contig_clusters;
2771                } else if ((rec_end - cpos) <= contig_clusters) {
2772                        /*
2773                         * Breaking off contig_clusters at the tail of
2774                         * this extent will cover cpos.
2775                         */
2776                        *cow_start = rec_end - contig_clusters;
2777                        *cow_len = contig_clusters;
2778                } else if ((rec_end - cpos) <= want_clusters) {
2779                        /*
2780                         * While we can't fit the entire write in this
2781                         * extent, we know that the write goes from cpos
2782                         * to the end of the extent.  Break that off.
2783                         * We try to break it at some multiple of
2784                         * contig_clusters from the front of the extent.
2785                         * Failing that (ie, cpos is within
2786                         * contig_clusters of the front), we'll CoW the
2787                         * entire extent.
2788                         */
2789                        *cow_start = ocfs2_cow_align_start(inode->i_sb,
2790                                                           *cow_start, cpos);
2791                        *cow_len = rec_end - *cow_start;
2792                } else {
2793                        /*
2794                         * Ok, the entire write lives in the middle of
2795                         * this extent.  Let's try to slice the extent up
2796                         * nicely.  Optimally, our CoW region starts at
2797                         * m*contig_clusters from the beginning of the
2798                         * extent and goes for n*contig_clusters,
2799                         * covering the entire write.
2800                         */
2801                        *cow_start = ocfs2_cow_align_start(inode->i_sb,
2802                                                           *cow_start, cpos);
2803
2804                        want_clusters = (cpos + write_len) - *cow_start;
2805                        want_clusters = ocfs2_cow_align_length(inode->i_sb,
2806                                                               want_clusters);
2807                        if (*cow_start + want_clusters <= rec_end)
2808                                *cow_len = want_clusters;
2809                        else
2810                                *cow_len = rec_end - *cow_start;
2811                }
2812
2813                /* Have we covered our entire write yet? */
2814                if ((*cow_start + *cow_len) >= (cpos + write_len))
2815                        break;
2816
2817                /*
2818                 * If we reach the end of the extent block and don't get enough
2819                 * clusters, continue with the next extent block if possible.
2820                 */
2821                if (i + 1 == le16_to_cpu(el->l_next_free_rec) &&
2822                    eb && eb->h_next_leaf_blk) {
2823                        brelse(eb_bh);
2824                        eb_bh = NULL;
2825
2826                        ret = ocfs2_read_extent_block(INODE_CACHE(inode),
2827                                               le64_to_cpu(eb->h_next_leaf_blk),
2828                                               &eb_bh);
2829                        if (ret) {
2830                                mlog_errno(ret);
2831                                goto out;
2832                        }
2833
2834                        eb = (struct ocfs2_extent_block *) eb_bh->b_data;
2835                        el = &eb->h_list;
2836                        i = -1;
2837                }
2838        }
2839
2840out:
2841        brelse(eb_bh);
2842        return ret;
2843}
2844
2845/*
2846 * Prepare meta_ac, data_ac and calculate credits when we want to add some
2847 * num_clusters in data_tree "et" and change the refcount for the old
2848 * clusters(starting form p_cluster) in the refcount tree.
2849 *
2850 * Note:
2851 * 1. since we may split the old tree, so we at most will need num_clusters + 2
2852 *    more new leaf records.
2853 * 2. In some case, we may not need to reserve new clusters(e.g, reflink), so
2854 *    just give data_ac = NULL.
2855 */
2856static int ocfs2_lock_refcount_allocators(struct super_block *sb,
2857                                        u32 p_cluster, u32 num_clusters,
2858                                        struct ocfs2_extent_tree *et,
2859                                        struct ocfs2_caching_info *ref_ci,
2860                                        struct buffer_head *ref_root_bh,
2861                                        struct ocfs2_alloc_context **meta_ac,
2862                                        struct ocfs2_alloc_context **data_ac,
2863                                        int *credits)
2864{
2865        int ret = 0, meta_add = 0;
2866        int num_free_extents = ocfs2_num_free_extents(OCFS2_SB(sb), et);
2867
2868        if (num_free_extents < 0) {
2869                ret = num_free_extents;
2870                mlog_errno(ret);
2871                goto out;
2872        }
2873
2874        if (num_free_extents < num_clusters + 2)
2875                meta_add =
2876                        ocfs2_extend_meta_needed(et->et_root_el);
2877
2878        *credits += ocfs2_calc_extend_credits(sb, et->et_root_el,
2879                                              num_clusters + 2);
2880
2881        ret = ocfs2_calc_refcount_meta_credits(sb, ref_ci, ref_root_bh,
2882                                               p_cluster, num_clusters,
2883                                               &meta_add, credits);
2884        if (ret) {
2885                mlog_errno(ret);
2886                goto out;
2887        }
2888
2889        trace_ocfs2_lock_refcount_allocators(meta_add, *credits);
2890        ret = ocfs2_reserve_new_metadata_blocks(OCFS2_SB(sb), meta_add,
2891                                                meta_ac);
2892        if (ret) {
2893                mlog_errno(ret);
2894                goto out;
2895        }
2896
2897        if (data_ac) {
2898                ret = ocfs2_reserve_clusters(OCFS2_SB(sb), num_clusters,
2899                                             data_ac);
2900                if (ret)
2901                        mlog_errno(ret);
2902        }
2903
2904out:
2905        if (ret) {
2906                if (*meta_ac) {
2907                        ocfs2_free_alloc_context(*meta_ac);
2908                        *meta_ac = NULL;
2909                }
2910        }
2911
2912        return ret;
2913}
2914
2915static int ocfs2_clear_cow_buffer(handle_t *handle, struct buffer_head *bh)
2916{
2917        BUG_ON(buffer_dirty(bh));
2918
2919        clear_buffer_mapped(bh);
2920
2921        return 0;
2922}
2923
2924int ocfs2_duplicate_clusters_by_page(handle_t *handle,
2925                                     struct file *file,
2926                                     u32 cpos, u32 old_cluster,
2927                                     u32 new_cluster, u32 new_len)
2928{
2929        int ret = 0, partial;
2930        struct inode *inode = file->f_path.dentry->d_inode;
2931        struct ocfs2_caching_info *ci = INODE_CACHE(inode);
2932        struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
2933        u64 new_block = ocfs2_clusters_to_blocks(sb, new_cluster);
2934        struct page *page;
2935        pgoff_t page_index;
2936        unsigned int from, to, readahead_pages;
2937        loff_t offset, end, map_end;
2938        struct address_space *mapping = inode->i_mapping;
2939
2940        trace_ocfs2_duplicate_clusters_by_page(cpos, old_cluster,
2941                                               new_cluster, new_len);
2942
2943        readahead_pages =
2944                (ocfs2_cow_contig_clusters(sb) <<
2945                 OCFS2_SB(sb)->s_clustersize_bits) >> PAGE_CACHE_SHIFT;
2946        offset = ((loff_t)cpos) << OCFS2_SB(sb)->s_clustersize_bits;
2947        end = offset + (new_len << OCFS2_SB(sb)->s_clustersize_bits);
2948        /*
2949         * We only duplicate pages until we reach the page contains i_size - 1.
2950         * So trim 'end' to i_size.
2951         */
2952        if (end > i_size_read(inode))
2953                end = i_size_read(inode);
2954
2955        while (offset < end) {
2956                page_index = offset >> PAGE_CACHE_SHIFT;
2957                map_end = ((loff_t)page_index + 1) << PAGE_CACHE_SHIFT;
2958                if (map_end > end)
2959                        map_end = end;
2960
2961                /* from, to is the offset within the page. */
2962                from = offset & (PAGE_CACHE_SIZE - 1);
2963                to = PAGE_CACHE_SIZE;
2964                if (map_end & (PAGE_CACHE_SIZE - 1))
2965                        to = map_end & (PAGE_CACHE_SIZE - 1);
2966
2967                page = find_or_create_page(mapping, page_index, GFP_NOFS);
2968
2969                /*
2970                 * In case PAGE_CACHE_SIZE <= CLUSTER_SIZE, This page
2971                 * can't be dirtied before we CoW it out.
2972                 */
2973                if (PAGE_CACHE_SIZE <= OCFS2_SB(sb)->s_clustersize)
2974                        BUG_ON(PageDirty(page));
2975
2976                if (PageReadahead(page)) {
2977                        page_cache_async_readahead(mapping,
2978                                                   &file->f_ra, file,
2979                                                   page, page_index,
2980                                                   readahead_pages);
2981                }
2982
2983                if (!PageUptodate(page)) {
2984                        ret = block_read_full_page(page, ocfs2_get_block);
2985                        if (ret) {
2986                                mlog_errno(ret);
2987                                goto unlock;
2988                        }
2989                        lock_page(page);
2990                }
2991
2992                if (page_has_buffers(page)) {
2993                        ret = walk_page_buffers(handle, page_buffers(page),
2994                                                from, to, &partial,
2995                                                ocfs2_clear_cow_buffer);
2996                        if (ret) {
2997                                mlog_errno(ret);
2998                                goto unlock;
2999                        }
3000                }
3001
3002                ocfs2_map_and_dirty_page(inode, handle, from, to,
3003                                         page, 0, &new_block);
3004                mark_page_accessed(page);
3005unlock:
3006                unlock_page(page);
3007                page_cache_release(page);
3008                page = NULL;
3009                offset = map_end;
3010                if (ret)
3011                        break;
3012        }
3013
3014        return ret;
3015}
3016
3017int ocfs2_duplicate_clusters_by_jbd(handle_t *handle,
3018                                    struct file *file,
3019                                    u32 cpos, u32 old_cluster,
3020                                    u32 new_cluster, u32 new_len)
3021{
3022        int ret = 0;
3023        struct inode *inode = file->f_path.dentry->d_inode;
3024        struct super_block *sb = inode->i_sb;
3025        struct ocfs2_caching_info *ci = INODE_CACHE(inode);
3026        int i, blocks = ocfs2_clusters_to_blocks(sb, new_len);
3027        u64 old_block = ocfs2_clusters_to_blocks(sb, old_cluster);
3028        u64 new_block = ocfs2_clusters_to_blocks(sb, new_cluster);
3029        struct ocfs2_super *osb = OCFS2_SB(sb);
3030        struct buffer_head *old_bh = NULL;
3031        struct buffer_head *new_bh = NULL;
3032
3033        trace_ocfs2_duplicate_clusters_by_page(cpos, old_cluster,
3034                                               new_cluster, new_len);
3035
3036        for (i = 0; i < blocks; i++, old_block++, new_block++) {
3037                new_bh = sb_getblk(osb->sb, new_block);
3038                if (new_bh == NULL) {
3039                        ret = -EIO;
3040                        mlog_errno(ret);
3041                        break;
3042                }
3043
3044                ocfs2_set_new_buffer_uptodate(ci, new_bh);
3045
3046                ret = ocfs2_read_block(ci, old_block, &old_bh, NULL);
3047                if (ret) {
3048                        mlog_errno(ret);
3049                        break;
3050                }
3051
3052                ret = ocfs2_journal_access(handle, ci, new_bh,
3053                                           OCFS2_JOURNAL_ACCESS_CREATE);
3054                if (ret) {
3055                        mlog_errno(ret);
3056                        break;
3057                }
3058
3059                memcpy(new_bh->b_data, old_bh->b_data, sb->s_blocksize);
3060                ocfs2_journal_dirty(handle, new_bh);
3061
3062                brelse(new_bh);
3063                brelse(old_bh);
3064                new_bh = NULL;
3065                old_bh = NULL;
3066        }
3067
3068        brelse(new_bh);
3069        brelse(old_bh);
3070        return ret;
3071}
3072
3073static int ocfs2_clear_ext_refcount(handle_t *handle,
3074                                    struct ocfs2_extent_tree *et,
3075                                    u32 cpos, u32 p_cluster, u32 len,
3076                                    unsigned int ext_flags,
3077                                    struct ocfs2_alloc_context *meta_ac,
3078                                    struct ocfs2_cached_dealloc_ctxt *dealloc)
3079{
3080        int ret, index;
3081        struct ocfs2_extent_rec replace_rec;
3082        struct ocfs2_path *path = NULL;
3083        struct ocfs2_extent_list *el;
3084        struct super_block *sb = ocfs2_metadata_cache_get_super(et->et_ci);
3085        u64 ino = ocfs2_metadata_cache_owner(et->et_ci);
3086
3087        trace_ocfs2_clear_ext_refcount((unsigned long long)ino,
3088                                       cpos, len, p_cluster, ext_flags);
3089
3090        memset(&replace_rec, 0, sizeof(replace_rec));
3091        replace_rec.e_cpos = cpu_to_le32(cpos);
3092        replace_rec.e_leaf_clusters = cpu_to_le16(len);
3093        replace_rec.e_blkno = cpu_to_le64(ocfs2_clusters_to_blocks(sb,
3094                                                                   p_cluster));
3095        replace_rec.e_flags = ext_flags;
3096        replace_rec.e_flags &= ~OCFS2_EXT_REFCOUNTED;
3097
3098        path = ocfs2_new_path_from_et(et);
3099        if (!path) {
3100                ret = -ENOMEM;
3101                mlog_errno(ret);
3102                goto out;
3103        }
3104
3105        ret = ocfs2_find_path(et->et_ci, path, cpos);
3106        if (ret) {
3107                mlog_errno(ret);
3108                goto out;
3109        }
3110
3111        el = path_leaf_el(path);
3112
3113        index = ocfs2_search_extent_list(el, cpos);
3114        if (index == -1 || index >= le16_to_cpu(el->l_next_free_rec)) {
3115                ocfs2_error(sb,
3116                            "Inode %llu has an extent at cpos %u which can no "
3117                            "longer be found.\n",
3118                            (unsigned long long)ino, cpos);
3119                ret = -EROFS;
3120                goto out;
3121        }
3122
3123        ret = ocfs2_split_extent(handle, et, path, index,
3124                                 &replace_rec, meta_ac, dealloc);
3125        if (ret)
3126                mlog_errno(ret);
3127
3128out:
3129        ocfs2_free_path(path);
3130        return ret;
3131}
3132
3133static int ocfs2_replace_clusters(handle_t *handle,
3134                                  struct ocfs2_cow_context *context,
3135                                  u32 cpos, u32 old,
3136                                  u32 new, u32 len,
3137                                  unsigned int ext_flags)
3138{
3139        int ret;
3140        struct ocfs2_caching_info *ci = context->data_et.et_ci;
3141        u64 ino = ocfs2_metadata_cache_owner(ci);
3142
3143        trace_ocfs2_replace_clusters((unsigned long long)ino,
3144                                     cpos, old, new, len, ext_flags);
3145
3146        /*If the old clusters is unwritten, no need to duplicate. */
3147        if (!(ext_flags & OCFS2_EXT_UNWRITTEN)) {
3148                ret = context->cow_duplicate_clusters(handle, context->file,
3149                                                      cpos, old, new, len);
3150                if (ret) {
3151                        mlog_errno(ret);
3152                        goto out;
3153                }
3154        }
3155
3156        ret = ocfs2_clear_ext_refcount(handle, &context->data_et,
3157                                       cpos, new, len, ext_flags,
3158                                       context->meta_ac, &context->dealloc);
3159        if (ret)
3160                mlog_errno(ret);
3161out:
3162        return ret;
3163}
3164
3165int ocfs2_cow_sync_writeback(struct super_block *sb,
3166                             struct inode *inode,
3167                             u32 cpos, u32 num_clusters)
3168{
3169        int ret = 0;
3170        loff_t offset, end, map_end;
3171        pgoff_t page_index;
3172        struct page *page;
3173
3174        if (ocfs2_should_order_data(inode))
3175                return 0;
3176
3177        offset = ((loff_t)cpos) << OCFS2_SB(sb)->s_clustersize_bits;
3178        end = offset + (num_clusters << OCFS2_SB(sb)->s_clustersize_bits);
3179
3180        ret = filemap_fdatawrite_range(inode->i_mapping,
3181                                       offset, end - 1);
3182        if (ret < 0) {
3183                mlog_errno(ret);
3184                return ret;
3185        }
3186
3187        while (offset < end) {
3188                page_index = offset >> PAGE_CACHE_SHIFT;
3189                map_end = ((loff_t)page_index + 1) << PAGE_CACHE_SHIFT;
3190                if (map_end > end)
3191                        map_end = end;
3192
3193                page = find_or_create_page(inode->i_mapping,
3194                                           page_index, GFP_NOFS);
3195                BUG_ON(!page);
3196
3197                wait_on_page_writeback(page);
3198                if (PageError(page)) {
3199                        ret = -EIO;
3200                        mlog_errno(ret);
3201                } else
3202                        mark_page_accessed(page);
3203
3204                unlock_page(page);
3205                page_cache_release(page);
3206                page = NULL;
3207                offset = map_end;
3208                if (ret)
3209                        break;
3210        }
3211
3212        return ret;
3213}
3214
3215static int ocfs2_di_get_clusters(struct ocfs2_cow_context *context,
3216                                 u32 v_cluster, u32 *p_cluster,
3217                                 u32 *num_clusters,
3218                                 unsigned int *extent_flags)
3219{
3220        return ocfs2_get_clusters(context->inode, v_cluster, p_cluster,
3221                                  num_clusters, extent_flags);
3222}
3223
3224static int ocfs2_make_clusters_writable(struct super_block *sb,
3225                                        struct ocfs2_cow_context *context,
3226                                        u32 cpos, u32 p_cluster,
3227                                        u32 num_clusters, unsigned int e_flags)
3228{
3229        int ret, delete, index, credits =  0;
3230        u32 new_bit, new_len, orig_num_clusters;
3231        unsigned int set_len;
3232        struct ocfs2_super *osb = OCFS2_SB(sb);
3233        handle_t *handle;
3234        struct buffer_head *ref_leaf_bh = NULL;
3235        struct ocfs2_caching_info *ref_ci = &context->ref_tree->rf_ci;
3236        struct ocfs2_refcount_rec rec;
3237
3238        trace_ocfs2_make_clusters_writable(cpos, p_cluster,
3239                                           num_clusters, e_flags);
3240
3241        ret = ocfs2_lock_refcount_allocators(sb, p_cluster, num_clusters,
3242                                             &context->data_et,
3243                                             ref_ci,
3244                                             context->ref_root_bh,
3245                                             &context->meta_ac,
3246                                             &context->data_ac, &credits);
3247        if (ret) {
3248                mlog_errno(ret);
3249                return ret;
3250        }
3251
3252        if (context->post_refcount)
3253                credits += context->post_refcount->credits;
3254
3255        credits += context->extra_credits;
3256        handle = ocfs2_start_trans(osb, credits);
3257        if (IS_ERR(handle)) {
3258                ret = PTR_ERR(handle);
3259                mlog_errno(ret);
3260                goto out;
3261        }
3262
3263        orig_num_clusters = num_clusters;
3264
3265        while (num_clusters) {
3266                ret = ocfs2_get_refcount_rec(ref_ci, context->ref_root_bh,
3267                                             p_cluster, num_clusters,
3268                                             &rec, &index, &ref_leaf_bh);
3269                if (ret) {
3270                        mlog_errno(ret);
3271                        goto out_commit;
3272                }
3273
3274                BUG_ON(!rec.r_refcount);
3275                set_len = min((u64)p_cluster + num_clusters,
3276                              le64_to_cpu(rec.r_cpos) +
3277                              le32_to_cpu(rec.r_clusters)) - p_cluster;
3278
3279                /*
3280                 * There are many different situation here.
3281                 * 1. If refcount == 1, remove the flag and don't COW.
3282                 * 2. If refcount > 1, allocate clusters.
3283                 *    Here we may not allocate r_len once at a time, so continue
3284                 *    until we reach num_clusters.
3285                 */
3286                if (le32_to_cpu(rec.r_refcount) == 1) {
3287                        delete = 0;
3288                        ret = ocfs2_clear_ext_refcount(handle,
3289                                                       &context->data_et,
3290                                                       cpos, p_cluster,
3291                                                       set_len, e_flags,
3292                                                       context->meta_ac,
3293                                                       &context->dealloc);
3294                        if (ret) {
3295                                mlog_errno(ret);
3296                                goto out_commit;
3297                        }
3298                } else {
3299                        delete = 1;
3300
3301                        ret = __ocfs2_claim_clusters(handle,
3302                                                     context->data_ac,
3303                                                     1, set_len,
3304                                                     &new_bit, &new_len);
3305                        if (ret) {
3306                                mlog_errno(ret);
3307                                goto out_commit;
3308                        }
3309
3310                        ret = ocfs2_replace_clusters(handle, context,
3311                                                     cpos, p_cluster, new_bit,
3312                                                     new_len, e_flags);
3313                        if (ret) {
3314                                mlog_errno(ret);
3315                                goto out_commit;
3316                        }
3317                        set_len = new_len;
3318                }
3319
3320                ret = __ocfs2_decrease_refcount(handle, ref_ci,
3321                                                context->ref_root_bh,
3322                                                p_cluster, set_len,
3323                                                context->meta_ac,
3324                                                &context->dealloc, delete);
3325                if (ret) {
3326                        mlog_errno(ret);
3327                        goto out_commit;
3328                }
3329
3330                cpos += set_len;
3331                p_cluster += set_len;
3332                num_clusters -= set_len;
3333                brelse(ref_leaf_bh);
3334                ref_leaf_bh = NULL;
3335        }
3336
3337        /* handle any post_cow action. */
3338        if (context->post_refcount && context->post_refcount->func) {
3339                ret = context->post_refcount->func(context->inode, handle,
3340                                                context->post_refcount->para);
3341                if (ret) {
3342                        mlog_errno(ret);
3343                        goto out_commit;
3344                }
3345        }
3346
3347        /*
3348         * Here we should write the new page out first if we are
3349         * in write-back mode.
3350         */
3351        if (context->get_clusters == ocfs2_di_get_clusters) {
3352                ret = ocfs2_cow_sync_writeback(sb, context->inode, cpos,
3353                                               orig_num_clusters);
3354                if (ret)
3355                        mlog_errno(ret);
3356        }
3357
3358out_commit:
3359        ocfs2_commit_trans(osb, handle);
3360
3361out:
3362        if (context->data_ac) {
3363                ocfs2_free_alloc_context(context->data_ac);
3364                context->data_ac = NULL;
3365        }
3366        if (context->meta_ac) {
3367                ocfs2_free_alloc_context(context->meta_ac);
3368                context->meta_ac = NULL;
3369        }
3370        brelse(ref_leaf_bh);
3371
3372        return ret;
3373}
3374
3375static int ocfs2_replace_cow(struct ocfs2_cow_context *context)
3376{
3377        int ret = 0;
3378        struct inode *inode = context->inode;
3379        u32 cow_start = context->cow_start, cow_len = context->cow_len;
3380        u32 p_cluster, num_clusters;
3381        unsigned int ext_flags;
3382        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
3383
3384        if (!ocfs2_refcount_tree(OCFS2_SB(inode->i_sb))) {
3385                ocfs2_error(inode->i_sb, "Inode %lu want to use refcount "
3386                            "tree, but the feature bit is not set in the "
3387                            "super block.", inode->i_ino);
3388                return -EROFS;
3389        }
3390
3391        ocfs2_init_dealloc_ctxt(&context->dealloc);
3392
3393        while (cow_len) {
3394                ret = context->get_clusters(context, cow_start, &p_cluster,
3395                                            &num_clusters, &ext_flags);
3396                if (ret) {
3397                        mlog_errno(ret);
3398                        break;
3399                }
3400
3401                BUG_ON(!(ext_flags & OCFS2_EXT_REFCOUNTED));
3402
3403                if (cow_len < num_clusters)
3404                        num_clusters = cow_len;
3405
3406                ret = ocfs2_make_clusters_writable(inode->i_sb, context,
3407                                                   cow_start, p_cluster,
3408                                                   num_clusters, ext_flags);
3409                if (ret) {
3410                        mlog_errno(ret);
3411                        break;
3412                }
3413
3414                cow_len -= num_clusters;
3415                cow_start += num_clusters;
3416        }
3417
3418        if (ocfs2_dealloc_has_cluster(&context->dealloc)) {
3419                ocfs2_schedule_truncate_log_flush(osb, 1);
3420                ocfs2_run_deallocs(osb, &context->dealloc);
3421        }
3422
3423        return ret;
3424}
3425
3426static void ocfs2_readahead_for_cow(struct inode *inode,
3427                                    struct file *file,
3428                                    u32 start, u32 len)
3429{
3430        struct address_space *mapping;
3431        pgoff_t index;
3432        unsigned long num_pages;
3433        int cs_bits = OCFS2_SB(inode->i_sb)->s_clustersize_bits;
3434
3435        if (!file)
3436                return;
3437
3438        mapping = file->f_mapping;
3439        num_pages = (len << cs_bits) >> PAGE_CACHE_SHIFT;
3440        if (!num_pages)
3441                num_pages = 1;
3442
3443        index = ((loff_t)start << cs_bits) >> PAGE_CACHE_SHIFT;
3444        page_cache_sync_readahead(mapping, &file->f_ra, file,
3445                                  index, num_pages);
3446}
3447
3448/*
3449 * Starting at cpos, try to CoW write_len clusters.  Don't CoW
3450 * past max_cpos.  This will stop when it runs into a hole or an
3451 * unrefcounted extent.
3452 */
3453static int ocfs2_refcount_cow_hunk(struct inode *inode,
3454                                   struct file *file,
3455                                   struct buffer_head *di_bh,
3456                                   u32 cpos, u32 write_len, u32 max_cpos)
3457{
3458        int ret;
3459        u32 cow_start = 0, cow_len = 0;
3460        struct ocfs2_inode_info *oi = OCFS2_I(inode);
3461        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
3462        struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
3463        struct buffer_head *ref_root_bh = NULL;
3464        struct ocfs2_refcount_tree *ref_tree;
3465        struct ocfs2_cow_context *context = NULL;
3466
3467        BUG_ON(!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL));
3468
3469        ret = ocfs2_refcount_cal_cow_clusters(inode, &di->id2.i_list,
3470                                              cpos, write_len, max_cpos,
3471                                              &cow_start, &cow_len);
3472        if (ret) {
3473                mlog_errno(ret);
3474                goto out;
3475        }
3476
3477        trace_ocfs2_refcount_cow_hunk(OCFS2_I(inode)->ip_blkno,
3478                                      cpos, write_len, max_cpos,
3479                                      cow_start, cow_len);
3480
3481        BUG_ON(cow_len == 0);
3482
3483        ocfs2_readahead_for_cow(inode, file, cow_start, cow_len);
3484
3485        context = kzalloc(sizeof(struct ocfs2_cow_context), GFP_NOFS);
3486        if (!context) {
3487                ret = -ENOMEM;
3488                mlog_errno(ret);
3489                goto out;
3490        }
3491
3492        ret = ocfs2_lock_refcount_tree(osb, le64_to_cpu(di->i_refcount_loc),
3493                                       1, &ref_tree, &ref_root_bh);
3494        if (ret) {
3495                mlog_errno(ret);
3496                goto out;
3497        }
3498
3499        context->inode = inode;
3500        context->cow_start = cow_start;
3501        context->cow_len = cow_len;
3502        context->ref_tree = ref_tree;
3503        context->ref_root_bh = ref_root_bh;
3504        context->cow_duplicate_clusters = ocfs2_duplicate_clusters_by_page;
3505        context->get_clusters = ocfs2_di_get_clusters;
3506        context->file = file;
3507
3508        ocfs2_init_dinode_extent_tree(&context->data_et,
3509                                      INODE_CACHE(inode), di_bh);
3510
3511        ret = ocfs2_replace_cow(context);
3512        if (ret)
3513                mlog_errno(ret);
3514
3515        /*
3516         * truncate the extent map here since no matter whether we meet with
3517         * any error during the action, we shouldn't trust cached extent map
3518         * any more.
3519         */
3520        ocfs2_extent_map_trunc(inode, cow_start);
3521
3522        ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
3523        brelse(ref_root_bh);
3524out:
3525        kfree(context);
3526        return ret;
3527}
3528
3529/*
3530 * CoW any and all clusters between cpos and cpos+write_len.
3531 * Don't CoW past max_cpos.  If this returns successfully, all
3532 * clusters between cpos and cpos+write_len are safe to modify.
3533 */
3534int ocfs2_refcount_cow(struct inode *inode,
3535                       struct file *file,
3536                       struct buffer_head *di_bh,
3537                       u32 cpos, u32 write_len, u32 max_cpos)
3538{
3539        int ret = 0;
3540        u32 p_cluster, num_clusters;
3541        unsigned int ext_flags;
3542
3543        while (write_len) {
3544                ret = ocfs2_get_clusters(inode, cpos, &p_cluster,
3545                                         &num_clusters, &ext_flags);
3546                if (ret) {
3547                        mlog_errno(ret);
3548                        break;
3549                }
3550
3551                if (write_len < num_clusters)
3552                        num_clusters = write_len;
3553
3554                if (ext_flags & OCFS2_EXT_REFCOUNTED) {
3555                        ret = ocfs2_refcount_cow_hunk(inode, file, di_bh, cpos,
3556                                                      num_clusters, max_cpos);
3557                        if (ret) {
3558                                mlog_errno(ret);
3559                                break;
3560                        }
3561                }
3562
3563                write_len -= num_clusters;
3564                cpos += num_clusters;
3565        }
3566
3567        return ret;
3568}
3569
3570static int ocfs2_xattr_value_get_clusters(struct ocfs2_cow_context *context,
3571                                          u32 v_cluster, u32 *p_cluster,
3572                                          u32 *num_clusters,
3573                                          unsigned int *extent_flags)
3574{
3575        struct inode *inode = context->inode;
3576        struct ocfs2_xattr_value_root *xv = context->cow_object;
3577
3578        return ocfs2_xattr_get_clusters(inode, v_cluster, p_cluster,
3579                                        num_clusters, &xv->xr_list,
3580                                        extent_flags);
3581}
3582
3583/*
3584 * Given a xattr value root, calculate the most meta/credits we need for
3585 * refcount tree change if we truncate it to 0.
3586 */
3587int ocfs2_refcounted_xattr_delete_need(struct inode *inode,
3588                                       struct ocfs2_caching_info *ref_ci,
3589                                       struct buffer_head *ref_root_bh,
3590                                       struct ocfs2_xattr_value_root *xv,
3591                                       int *meta_add, int *credits)
3592{
3593        int ret = 0, index, ref_blocks = 0;
3594        u32 p_cluster, num_clusters;
3595        u32 cpos = 0, clusters = le32_to_cpu(xv->xr_clusters);
3596        struct ocfs2_refcount_block *rb;
3597        struct ocfs2_refcount_rec rec;
3598        struct buffer_head *ref_leaf_bh = NULL;
3599
3600        while (cpos < clusters) {
3601                ret = ocfs2_xattr_get_clusters(inode, cpos, &p_cluster,
3602                                               &num_clusters, &xv->xr_list,
3603                                               NULL);
3604                if (ret) {
3605                        mlog_errno(ret);
3606                        goto out;
3607                }
3608
3609                cpos += num_clusters;
3610
3611                while (num_clusters) {
3612                        ret = ocfs2_get_refcount_rec(ref_ci, ref_root_bh,
3613                                                     p_cluster, num_clusters,
3614                                                     &rec, &index,
3615                                                     &ref_leaf_bh);
3616                        if (ret) {
3617                                mlog_errno(ret);
3618                                goto out;
3619                        }
3620
3621                        BUG_ON(!rec.r_refcount);
3622
3623                        rb = (struct ocfs2_refcount_block *)ref_leaf_bh->b_data;
3624
3625                        /*
3626                         * We really don't know whether the other clusters is in
3627                         * this refcount block or not, so just take the worst
3628                         * case that all the clusters are in this block and each
3629                         * one will split a refcount rec, so totally we need
3630                         * clusters * 2 new refcount rec.
3631                         */
3632                        if (le16_to_cpu(rb->rf_records.rl_used) + clusters * 2 >
3633                            le16_to_cpu(rb->rf_records.rl_count))
3634                                ref_blocks++;
3635
3636                        *credits += 1;
3637                        brelse(ref_leaf_bh);
3638                        ref_leaf_bh = NULL;
3639
3640                        if (num_clusters <= le32_to_cpu(rec.r_clusters))
3641                                break;
3642                        else
3643                                num_clusters -= le32_to_cpu(rec.r_clusters);
3644                        p_cluster += num_clusters;
3645                }
3646        }
3647
3648        *meta_add += ref_blocks;
3649        if (!ref_blocks)
3650                goto out;
3651
3652        rb = (struct ocfs2_refcount_block *)ref_root_bh->b_data;
3653        if (le32_to_cpu(rb->rf_flags) & OCFS2_REFCOUNT_TREE_FL)
3654                *credits += OCFS2_EXPAND_REFCOUNT_TREE_CREDITS;
3655        else {
3656                struct ocfs2_extent_tree et;
3657
3658                ocfs2_init_refcount_extent_tree(&et, ref_ci, ref_root_bh);
3659                *credits += ocfs2_calc_extend_credits(inode->i_sb,
3660                                                      et.et_root_el,
3661                                                      ref_blocks);
3662        }
3663
3664out:
3665        brelse(ref_leaf_bh);
3666        return ret;
3667}
3668
3669/*
3670 * Do CoW for xattr.
3671 */
3672int ocfs2_refcount_cow_xattr(struct inode *inode,
3673                             struct ocfs2_dinode *di,
3674                             struct ocfs2_xattr_value_buf *vb,
3675                             struct ocfs2_refcount_tree *ref_tree,
3676                             struct buffer_head *ref_root_bh,
3677                             u32 cpos, u32 write_len,
3678                             struct ocfs2_post_refcount *post)
3679{
3680        int ret;
3681        struct ocfs2_xattr_value_root *xv = vb->vb_xv;
3682        struct ocfs2_inode_info *oi = OCFS2_I(inode);
3683        struct ocfs2_cow_context *context = NULL;
3684        u32 cow_start, cow_len;
3685
3686        BUG_ON(!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL));
3687
3688        ret = ocfs2_refcount_cal_cow_clusters(inode, &xv->xr_list,
3689                                              cpos, write_len, UINT_MAX,
3690                                              &cow_start, &cow_len);
3691        if (ret) {
3692                mlog_errno(ret);
3693                goto out;
3694        }
3695
3696        BUG_ON(cow_len == 0);
3697
3698        context = kzalloc(sizeof(struct ocfs2_cow_context), GFP_NOFS);
3699        if (!context) {
3700                ret = -ENOMEM;
3701                mlog_errno(ret);
3702                goto out;
3703        }
3704
3705        context->inode = inode;
3706        context->cow_start = cow_start;
3707        context->cow_len = cow_len;
3708        context->ref_tree = ref_tree;
3709        context->ref_root_bh = ref_root_bh;
3710        context->cow_object = xv;
3711
3712        context->cow_duplicate_clusters = ocfs2_duplicate_clusters_by_jbd;
3713        /* We need the extra credits for duplicate_clusters by jbd. */
3714        context->extra_credits =
3715                ocfs2_clusters_to_blocks(inode->i_sb, 1) * cow_len;
3716        context->get_clusters = ocfs2_xattr_value_get_clusters;
3717        context->post_refcount = post;
3718
3719        ocfs2_init_xattr_value_extent_tree(&context->data_et,
3720                                           INODE_CACHE(inode), vb);
3721
3722        ret = ocfs2_replace_cow(context);
3723        if (ret)
3724                mlog_errno(ret);
3725
3726out:
3727        kfree(context);
3728        return ret;
3729}
3730
3731/*
3732 * Insert a new extent into refcount tree and mark a extent rec
3733 * as refcounted in the dinode tree.
3734 */
3735int ocfs2_add_refcount_flag(struct inode *inode,
3736                            struct ocfs2_extent_tree *data_et,
3737                            struct ocfs2_caching_info *ref_ci,
3738                            struct buffer_head *ref_root_bh,
3739                            u32 cpos, u32 p_cluster, u32 num_clusters,
3740                            struct ocfs2_cached_dealloc_ctxt *dealloc,
3741                            struct ocfs2_post_refcount *post)
3742{
3743        int ret;
3744        handle_t *handle;
3745        int credits = 1, ref_blocks = 0;
3746        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
3747        struct ocfs2_alloc_context *meta_ac = NULL;
3748
3749        ret = ocfs2_calc_refcount_meta_credits(inode->i_sb,
3750                                               ref_ci, ref_root_bh,
3751                                               p_cluster, num_clusters,
3752                                               &ref_blocks, &credits);
3753        if (ret) {
3754                mlog_errno(ret);
3755                goto out;
3756        }
3757
3758        trace_ocfs2_add_refcount_flag(ref_blocks, credits);
3759
3760        if (ref_blocks) {
3761                ret = ocfs2_reserve_new_metadata_blocks(OCFS2_SB(inode->i_sb),
3762                                                        ref_blocks, &meta_ac);
3763                if (ret) {
3764                        mlog_errno(ret);
3765                        goto out;
3766                }
3767        }
3768
3769        if (post)
3770                credits += post->credits;
3771
3772        handle = ocfs2_start_trans(osb, credits);
3773        if (IS_ERR(handle)) {
3774                ret = PTR_ERR(handle);
3775                mlog_errno(ret);
3776                goto out;
3777        }
3778
3779        ret = ocfs2_mark_extent_refcounted(inode, data_et, handle,
3780                                           cpos, num_clusters, p_cluster,
3781                                           meta_ac, dealloc);
3782        if (ret) {
3783                mlog_errno(ret);
3784                goto out_commit;
3785        }
3786
3787        ret = __ocfs2_increase_refcount(handle, ref_ci, ref_root_bh,
3788                                        p_cluster, num_clusters, 0,
3789                                        meta_ac, dealloc);
3790        if (ret) {
3791                mlog_errno(ret);
3792                goto out_commit;
3793        }
3794
3795        if (post && post->func) {
3796                ret = post->func(inode, handle, post->para);
3797                if (ret)
3798                        mlog_errno(ret);
3799        }
3800
3801out_commit:
3802        ocfs2_commit_trans(osb, handle);
3803out:
3804        if (meta_ac)
3805                ocfs2_free_alloc_context(meta_ac);
3806        return ret;
3807}
3808
3809static int ocfs2_change_ctime(struct inode *inode,
3810                              struct buffer_head *di_bh)
3811{
3812        int ret;
3813        handle_t *handle;
3814        struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
3815
3816        handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb),
3817                                   OCFS2_INODE_UPDATE_CREDITS);
3818        if (IS_ERR(handle)) {
3819                ret = PTR_ERR(handle);
3820                mlog_errno(ret);
3821                goto out;
3822        }
3823
3824        ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
3825                                      OCFS2_JOURNAL_ACCESS_WRITE);
3826        if (ret) {
3827                mlog_errno(ret);
3828                goto out_commit;
3829        }
3830
3831        inode->i_ctime = CURRENT_TIME;
3832        di->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
3833        di->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
3834
3835        ocfs2_journal_dirty(handle, di_bh);
3836
3837out_commit:
3838        ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
3839out:
3840        return ret;
3841}
3842
3843static int ocfs2_attach_refcount_tree(struct inode *inode,
3844                                      struct buffer_head *di_bh)
3845{
3846        int ret, data_changed = 0;
3847        struct buffer_head *ref_root_bh = NULL;
3848        struct ocfs2_inode_info *oi = OCFS2_I(inode);
3849        struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
3850        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
3851        struct ocfs2_refcount_tree *ref_tree;
3852        unsigned int ext_flags;
3853        loff_t size;
3854        u32 cpos, num_clusters, clusters, p_cluster;
3855        struct ocfs2_cached_dealloc_ctxt dealloc;
3856        struct ocfs2_extent_tree di_et;
3857
3858        ocfs2_init_dealloc_ctxt(&dealloc);
3859
3860        if (!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL)) {
3861                ret = ocfs2_create_refcount_tree(inode, di_bh);
3862                if (ret) {
3863                        mlog_errno(ret);
3864                        goto out;
3865                }
3866        }
3867
3868        BUG_ON(!di->i_refcount_loc);
3869        ret = ocfs2_lock_refcount_tree(osb,
3870                                       le64_to_cpu(di->i_refcount_loc), 1,
3871                                       &ref_tree, &ref_root_bh);
3872        if (ret) {
3873                mlog_errno(ret);
3874                goto out;
3875        }
3876
3877        if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
3878                goto attach_xattr;
3879
3880        ocfs2_init_dinode_extent_tree(&di_et, INODE_CACHE(inode), di_bh);
3881
3882        size = i_size_read(inode);
3883        clusters = ocfs2_clusters_for_bytes(inode->i_sb, size);
3884
3885        cpos = 0;
3886        while (cpos < clusters) {
3887                ret = ocfs2_get_clusters(inode, cpos, &p_cluster,
3888                                         &num_clusters, &ext_flags);
3889
3890                if (p_cluster && !(ext_flags & OCFS2_EXT_REFCOUNTED)) {
3891                        ret = ocfs2_add_refcount_flag(inode, &di_et,
3892                                                      &ref_tree->rf_ci,
3893                                                      ref_root_bh, cpos,
3894                                                      p_cluster, num_clusters,
3895                                                      &dealloc, NULL);
3896                        if (ret) {
3897                                mlog_errno(ret);
3898                                goto unlock;
3899                        }
3900
3901                        data_changed = 1;
3902                }
3903                cpos += num_clusters;
3904        }
3905
3906attach_xattr:
3907        if (oi->ip_dyn_features & OCFS2_HAS_XATTR_FL) {
3908                ret = ocfs2_xattr_attach_refcount_tree(inode, di_bh,
3909                                                       &ref_tree->rf_ci,
3910                                                       ref_root_bh,
3911                                                       &dealloc);
3912                if (ret) {
3913                        mlog_errno(ret);
3914                        goto unlock;
3915                }
3916        }
3917
3918        if (data_changed) {
3919                ret = ocfs2_change_ctime(inode, di_bh);
3920                if (ret)
3921                        mlog_errno(ret);
3922        }
3923
3924unlock:
3925        ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
3926        brelse(ref_root_bh);
3927
3928        if (!ret && ocfs2_dealloc_has_cluster(&dealloc)) {
3929                ocfs2_schedule_truncate_log_flush(osb, 1);
3930                ocfs2_run_deallocs(osb, &dealloc);
3931        }
3932out:
3933        /*
3934         * Empty the extent map so that we may get the right extent
3935         * record from the disk.
3936         */
3937        ocfs2_extent_map_trunc(inode, 0);
3938
3939        return ret;
3940}
3941
3942static int ocfs2_add_refcounted_extent(struct inode *inode,
3943                                   struct ocfs2_extent_tree *et,
3944                                   struct ocfs2_caching_info *ref_ci,
3945                                   struct buffer_head *ref_root_bh,
3946                                   u32 cpos, u32 p_cluster, u32 num_clusters,
3947                                   unsigned int ext_flags,
3948                                   struct ocfs2_cached_dealloc_ctxt *dealloc)
3949{
3950        int ret;
3951        handle_t *handle;
3952        int credits = 0;
3953        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
3954        struct ocfs2_alloc_context *meta_ac = NULL;
3955
3956        ret = ocfs2_lock_refcount_allocators(inode->i_sb,
3957                                             p_cluster, num_clusters,
3958                                             et, ref_ci,
3959                                             ref_root_bh, &meta_ac,
3960                                             NULL, &credits);
3961        if (ret) {
3962                mlog_errno(ret);
3963                goto out;
3964        }
3965
3966        handle = ocfs2_start_trans(osb, credits);
3967        if (IS_ERR(handle)) {
3968                ret = PTR_ERR(handle);
3969                mlog_errno(ret);
3970                goto out;
3971        }
3972
3973        ret = ocfs2_insert_extent(handle, et, cpos,
3974                        ocfs2_clusters_to_blocks(inode->i_sb, p_cluster),
3975                        num_clusters, ext_flags, meta_ac);
3976        if (ret) {
3977                mlog_errno(ret);
3978                goto out_commit;
3979        }
3980
3981        ret = ocfs2_increase_refcount(handle, ref_ci, ref_root_bh,
3982                                      p_cluster, num_clusters,
3983                                      meta_ac, dealloc);
3984        if (ret)
3985                mlog_errno(ret);
3986
3987out_commit:
3988        ocfs2_commit_trans(osb, handle);
3989out:
3990        if (meta_ac)
3991                ocfs2_free_alloc_context(meta_ac);
3992        return ret;
3993}
3994
3995static int ocfs2_duplicate_inline_data(struct inode *s_inode,
3996                                       struct buffer_head *s_bh,
3997                                       struct inode *t_inode,
3998                                       struct buffer_head *t_bh)
3999{
4000        int ret;
4001        handle_t *handle;
4002        struct ocfs2_super *osb = OCFS2_SB(s_inode->i_sb);
4003        struct ocfs2_dinode *s_di = (struct ocfs2_dinode *)s_bh->b_data;
4004        struct ocfs2_dinode *t_di = (struct ocfs2_dinode *)t_bh->b_data;
4005
4006        BUG_ON(!(OCFS2_I(s_inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL));
4007
4008        handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
4009        if (IS_ERR(handle)) {
4010                ret = PTR_ERR(handle);
4011                mlog_errno(ret);
4012                goto out;
4013        }
4014
4015        ret = ocfs2_journal_access_di(handle, INODE_CACHE(t_inode), t_bh,
4016                                      OCFS2_JOURNAL_ACCESS_WRITE);
4017        if (ret) {
4018                mlog_errno(ret);
4019                goto out_commit;
4020        }
4021
4022        t_di->id2.i_data.id_count = s_di->id2.i_data.id_count;
4023        memcpy(t_di->id2.i_data.id_data, s_di->id2.i_data.id_data,
4024               le16_to_cpu(s_di->id2.i_data.id_count));
4025        spin_lock(&OCFS2_I(t_inode)->ip_lock);
4026        OCFS2_I(t_inode)->ip_dyn_features |= OCFS2_INLINE_DATA_FL;
4027        t_di->i_dyn_features = cpu_to_le16(OCFS2_I(t_inode)->ip_dyn_features);
4028        spin_unlock(&OCFS2_I(t_inode)->ip_lock);
4029
4030        ocfs2_journal_dirty(handle, t_bh);
4031
4032out_commit:
4033        ocfs2_commit_trans(osb, handle);
4034out:
4035        return ret;
4036}
4037
4038static int ocfs2_duplicate_extent_list(struct inode *s_inode,
4039                                struct inode *t_inode,
4040                                struct buffer_head *t_bh,
4041                                struct ocfs2_caching_info *ref_ci,
4042                                struct buffer_head *ref_root_bh,
4043                                struct ocfs2_cached_dealloc_ctxt *dealloc)
4044{
4045        int ret = 0;
4046        u32 p_cluster, num_clusters, clusters, cpos;
4047        loff_t size;
4048        unsigned int ext_flags;
4049        struct ocfs2_extent_tree et;
4050
4051        ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(t_inode), t_bh);
4052
4053        size = i_size_read(s_inode);
4054        clusters = ocfs2_clusters_for_bytes(s_inode->i_sb, size);
4055
4056        cpos = 0;
4057        while (cpos < clusters) {
4058                ret = ocfs2_get_clusters(s_inode, cpos, &p_cluster,
4059                                         &num_clusters, &ext_flags);
4060
4061                if (p_cluster) {
4062                        ret = ocfs2_add_refcounted_extent(t_inode, &et,
4063                                                          ref_ci, ref_root_bh,
4064                                                          cpos, p_cluster,
4065                                                          num_clusters,
4066                                                          ext_flags,
4067                                                          dealloc);
4068                        if (ret) {
4069                                mlog_errno(ret);
4070                                goto out;
4071                        }
4072                }
4073
4074                cpos += num_clusters;
4075        }
4076
4077out:
4078        return ret;
4079}
4080
4081/*
4082 * change the new file's attributes to the src.
4083 *
4084 * reflink creates a snapshot of a file, that means the attributes
4085 * must be identical except for three exceptions - nlink, ino, and ctime.
4086 */
4087static int ocfs2_complete_reflink(struct inode *s_inode,
4088                                  struct buffer_head *s_bh,
4089                                  struct inode *t_inode,
4090                                  struct buffer_head *t_bh,
4091                                  bool preserve)
4092{
4093        int ret;
4094        handle_t *handle;
4095        struct ocfs2_dinode *s_di = (struct ocfs2_dinode *)s_bh->b_data;
4096        struct ocfs2_dinode *di = (struct ocfs2_dinode *)t_bh->b_data;
4097        loff_t size = i_size_read(s_inode);
4098
4099        handle = ocfs2_start_trans(OCFS2_SB(t_inode->i_sb),
4100                                   OCFS2_INODE_UPDATE_CREDITS);
4101        if (IS_ERR(handle)) {
4102                ret = PTR_ERR(handle);
4103                mlog_errno(ret);
4104                return ret;
4105        }
4106
4107        ret = ocfs2_journal_access_di(handle, INODE_CACHE(t_inode), t_bh,
4108                                      OCFS2_JOURNAL_ACCESS_WRITE);
4109        if (ret) {
4110                mlog_errno(ret);
4111                goto out_commit;
4112        }
4113
4114        spin_lock(&OCFS2_I(t_inode)->ip_lock);
4115        OCFS2_I(t_inode)->ip_clusters = OCFS2_I(s_inode)->ip_clusters;
4116        OCFS2_I(t_inode)->ip_attr = OCFS2_I(s_inode)->ip_attr;
4117        OCFS2_I(t_inode)->ip_dyn_features = OCFS2_I(s_inode)->ip_dyn_features;
4118        spin_unlock(&OCFS2_I(t_inode)->ip_lock);
4119        i_size_write(t_inode, size);
4120        t_inode->i_blocks = s_inode->i_blocks;
4121
4122        di->i_xattr_inline_size = s_di->i_xattr_inline_size;
4123        di->i_clusters = s_di->i_clusters;
4124        di->i_size = s_di->i_size;
4125        di->i_dyn_features = s_di->i_dyn_features;
4126        di->i_attr = s_di->i_attr;
4127
4128        if (preserve) {
4129                t_inode->i_uid = s_inode->i_uid;
4130                t_inode->i_gid = s_inode->i_gid;
4131                t_inode->i_mode = s_inode->i_mode;
4132                di->i_uid = s_di->i_uid;
4133                di->i_gid = s_di->i_gid;
4134                di->i_mode = s_di->i_mode;
4135
4136                /*
4137                 * update time.
4138                 * we want mtime to appear identical to the source and
4139                 * update ctime.
4140                 */
4141                t_inode->i_ctime = CURRENT_TIME;
4142
4143                di->i_ctime = cpu_to_le64(t_inode->i_ctime.tv_sec);
4144                di->i_ctime_nsec = cpu_to_le32(t_inode->i_ctime.tv_nsec);
4145
4146                t_inode->i_mtime = s_inode->i_mtime;
4147                di->i_mtime = s_di->i_mtime;
4148                di->i_mtime_nsec = s_di->i_mtime_nsec;
4149        }
4150
4151        ocfs2_journal_dirty(handle, t_bh);
4152
4153out_commit:
4154        ocfs2_commit_trans(OCFS2_SB(t_inode->i_sb), handle);
4155        return ret;
4156}
4157
4158static int ocfs2_create_reflink_node(struct inode *s_inode,
4159                                     struct buffer_head *s_bh,
4160                                     struct inode *t_inode,
4161                                     struct buffer_head *t_bh,
4162                                     bool preserve)
4163{
4164        int ret;
4165        struct buffer_head *ref_root_bh = NULL;
4166        struct ocfs2_cached_dealloc_ctxt dealloc;
4167        struct ocfs2_super *osb = OCFS2_SB(s_inode->i_sb);
4168        struct ocfs2_refcount_block *rb;
4169        struct ocfs2_dinode *di = (struct ocfs2_dinode *)s_bh->b_data;
4170        struct ocfs2_refcount_tree *ref_tree;
4171
4172        ocfs2_init_dealloc_ctxt(&dealloc);
4173
4174        ret = ocfs2_set_refcount_tree(t_inode, t_bh,
4175                                      le64_to_cpu(di->i_refcount_loc));
4176        if (ret) {
4177                mlog_errno(ret);
4178                goto out;
4179        }
4180
4181        if (OCFS2_I(s_inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
4182                ret = ocfs2_duplicate_inline_data(s_inode, s_bh,
4183                                                  t_inode, t_bh);
4184                if (ret)
4185                        mlog_errno(ret);
4186                goto out;
4187        }
4188
4189        ret = ocfs2_lock_refcount_tree(osb, le64_to_cpu(di->i_refcount_loc),
4190                                       1, &ref_tree, &ref_root_bh);
4191        if (ret) {
4192                mlog_errno(ret);
4193                goto out;
4194        }
4195        rb = (struct ocfs2_refcount_block *)ref_root_bh->b_data;
4196
4197        ret = ocfs2_duplicate_extent_list(s_inode, t_inode, t_bh,
4198                                          &ref_tree->rf_ci, ref_root_bh,
4199                                          &dealloc);
4200        if (ret) {
4201                mlog_errno(ret);
4202                goto out_unlock_refcount;
4203        }
4204
4205out_unlock_refcount:
4206        ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
4207        brelse(ref_root_bh);
4208out:
4209        if (ocfs2_dealloc_has_cluster(&dealloc)) {
4210                ocfs2_schedule_truncate_log_flush(osb, 1);
4211                ocfs2_run_deallocs(osb, &dealloc);
4212        }
4213
4214        return ret;
4215}
4216
4217static int __ocfs2_reflink(struct dentry *old_dentry,
4218                           struct buffer_head *old_bh,
4219                           struct inode *new_inode,
4220                           bool preserve)
4221{
4222        int ret;
4223        struct inode *inode = old_dentry->d_inode;
4224        struct buffer_head *new_bh = NULL;
4225
4226        if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE) {
4227                ret = -EINVAL;
4228                mlog_errno(ret);
4229                goto out;
4230        }
4231
4232        ret = filemap_fdatawrite(inode->i_mapping);
4233        if (ret) {
4234                mlog_errno(ret);
4235                goto out;
4236        }
4237
4238        ret = ocfs2_attach_refcount_tree(inode, old_bh);
4239        if (ret) {
4240                mlog_errno(ret);
4241                goto out;
4242        }
4243
4244        mutex_lock_nested(&new_inode->i_mutex, I_MUTEX_CHILD);
4245        ret = ocfs2_inode_lock_nested(new_inode, &new_bh, 1,
4246                                      OI_LS_REFLINK_TARGET);
4247        if (ret) {
4248                mlog_errno(ret);
4249                goto out_unlock;
4250        }
4251
4252        ret = ocfs2_create_reflink_node(inode, old_bh,
4253                                        new_inode, new_bh, preserve);
4254        if (ret) {
4255                mlog_errno(ret);
4256                goto inode_unlock;
4257        }
4258
4259        if (OCFS2_I(inode)->ip_dyn_features & OCFS2_HAS_XATTR_FL) {
4260                ret = ocfs2_reflink_xattrs(inode, old_bh,
4261                                           new_inode, new_bh,
4262                                           preserve);
4263                if (ret) {
4264                        mlog_errno(ret);
4265                        goto inode_unlock;
4266                }
4267        }
4268
4269        ret = ocfs2_complete_reflink(inode, old_bh,
4270                                     new_inode, new_bh, preserve);
4271        if (ret)
4272                mlog_errno(ret);
4273
4274inode_unlock:
4275        ocfs2_inode_unlock(new_inode, 1);
4276        brelse(new_bh);
4277out_unlock:
4278        mutex_unlock(&new_inode->i_mutex);
4279out:
4280        if (!ret) {
4281                ret = filemap_fdatawait(inode->i_mapping);
4282                if (ret)
4283                        mlog_errno(ret);
4284        }
4285        return ret;
4286}
4287
4288static int ocfs2_reflink(struct dentry *old_dentry, struct inode *dir,
4289                         struct dentry *new_dentry, bool preserve)
4290{
4291        int error;
4292        struct inode *inode = old_dentry->d_inode;
4293        struct buffer_head *old_bh = NULL;
4294        struct inode *new_orphan_inode = NULL;
4295
4296        if (!ocfs2_refcount_tree(OCFS2_SB(inode->i_sb)))
4297                return -EOPNOTSUPP;
4298
4299        error = ocfs2_create_inode_in_orphan(dir, inode->i_mode,
4300                                             &new_orphan_inode);
4301        if (error) {
4302                mlog_errno(error);
4303                goto out;
4304        }
4305
4306        error = ocfs2_inode_lock(inode, &old_bh, 1);
4307        if (error) {
4308                mlog_errno(error);
4309                goto out;
4310        }
4311
4312        down_write(&OCFS2_I(inode)->ip_xattr_sem);
4313        down_write(&OCFS2_I(inode)->ip_alloc_sem);
4314        error = __ocfs2_reflink(old_dentry, old_bh,
4315                                new_orphan_inode, preserve);
4316        up_write(&OCFS2_I(inode)->ip_alloc_sem);
4317        up_write(&OCFS2_I(inode)->ip_xattr_sem);
4318
4319        ocfs2_inode_unlock(inode, 1);
4320        brelse(old_bh);
4321
4322        if (error) {
4323                mlog_errno(error);
4324                goto out;
4325        }
4326
4327        /* If the security isn't preserved, we need to re-initialize them. */
4328        if (!preserve) {
4329                error = ocfs2_init_security_and_acl(dir, new_orphan_inode,
4330                                                    &new_dentry->d_name);
4331                if (error)
4332                        mlog_errno(error);
4333        }
4334out:
4335        if (!error) {
4336                error = ocfs2_mv_orphaned_inode_to_new(dir, new_orphan_inode,
4337                                                       new_dentry);
4338                if (error)
4339                        mlog_errno(error);
4340        }
4341
4342        if (new_orphan_inode) {
4343                /*
4344                 * We need to open_unlock the inode no matter whether we
4345                 * succeed or not, so that other nodes can delete it later.
4346                 */
4347                ocfs2_open_unlock(new_orphan_inode);
4348                if (error)
4349                        iput(new_orphan_inode);
4350        }
4351
4352        return error;
4353}
4354
4355/*
4356 * Below here are the bits used by OCFS2_IOC_REFLINK() to fake
4357 * sys_reflink().  This will go away when vfs_reflink() exists in
4358 * fs/namei.c.
4359 */
4360
4361/* copied from may_create in VFS. */
4362static inline int ocfs2_may_create(struct inode *dir, struct dentry *child)
4363{
4364        if (child->d_inode)
4365                return -EEXIST;
4366        if (IS_DEADDIR(dir))
4367                return -ENOENT;
4368        return inode_permission(dir, MAY_WRITE | MAY_EXEC);
4369}
4370
4371/**
4372 * ocfs2_vfs_reflink - Create a reference-counted link
4373 *
4374 * @old_dentry:        source dentry + inode
4375 * @dir:       directory to create the target
4376 * @new_dentry:        target dentry
4377 * @preserve:  if true, preserve all file attributes
4378 */
4379static int ocfs2_vfs_reflink(struct dentry *old_dentry, struct inode *dir,
4380                             struct dentry *new_dentry, bool preserve)
4381{
4382        struct inode *inode = old_dentry->d_inode;
4383        int error;
4384
4385        if (!inode)
4386                return -ENOENT;
4387
4388        error = ocfs2_may_create(dir, new_dentry);
4389        if (error)
4390                return error;
4391
4392        if (dir->i_sb != inode->i_sb)
4393                return -EXDEV;
4394
4395        /*
4396         * A reflink to an append-only or immutable file cannot be created.
4397         */
4398        if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
4399                return -EPERM;
4400
4401        /* Only regular files can be reflinked. */
4402        if (!S_ISREG(inode->i_mode))
4403                return -EPERM;
4404
4405        /*
4406         * If the caller wants to preserve ownership, they require the
4407         * rights to do so.
4408         */
4409        if (preserve) {
4410                if ((current_fsuid() != inode->i_uid) && !capable(CAP_CHOWN))
4411                        return -EPERM;
4412                if (!in_group_p(inode->i_gid) && !capable(CAP_CHOWN))
4413                        return -EPERM;
4414        }
4415
4416        /*
4417         * If the caller is modifying any aspect of the attributes, they
4418         * are not creating a snapshot.  They need read permission on the
4419         * file.
4420         */
4421        if (!preserve) {
4422                error = inode_permission(inode, MAY_READ);
4423                if (error)
4424                        return error;
4425        }
4426
4427        mutex_lock(&inode->i_mutex);
4428        dquot_initialize(dir);
4429        error = ocfs2_reflink(old_dentry, dir, new_dentry, preserve);
4430        mutex_unlock(&inode->i_mutex);
4431        if (!error)
4432                fsnotify_create(dir, new_dentry);
4433        return error;
4434}
4435/*
4436 * Most codes are copied from sys_linkat.
4437 */
4438int ocfs2_reflink_ioctl(struct inode *inode,
4439                        const char __user *oldname,
4440                        const char __user *newname,
4441                        bool preserve)
4442{
4443        struct dentry *new_dentry;
4444        struct path old_path, new_path;
4445        int error;
4446
4447        if (!ocfs2_refcount_tree(OCFS2_SB(inode->i_sb)))
4448                return -EOPNOTSUPP;
4449
4450        error = user_path_at(AT_FDCWD, oldname, 0, &old_path);
4451        if (error) {
4452                mlog_errno(error);
4453                return error;
4454        }
4455
4456        new_dentry = user_path_create(AT_FDCWD, newname, &new_path, 0);
4457        error = PTR_ERR(new_dentry);
4458        if (IS_ERR(new_dentry)) {
4459                mlog_errno(error);
4460                goto out;
4461        }
4462
4463        error = -EXDEV;
4464        if (old_path.mnt != new_path.mnt) {
4465                mlog_errno(error);
4466                goto out_dput;
4467        }
4468
4469        error = ocfs2_vfs_reflink(old_path.dentry,
4470                                  new_path.dentry->d_inode,
4471                                  new_dentry, preserve);
4472out_dput:
4473        done_path_create(&new_path, new_dentry);
4474out:
4475        path_put(&old_path);
4476
4477        return error;
4478}
4479
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