fs/ocfs2/refcounttree.c

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