fs/hfsplus/bnode.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  linux/fs/hfsplus/bnode.c
   4  *
   5  * Copyright (C) 2001
   6  * Brad Boyer (flar@allandria.com)
   7  * (C) 2003 Ardis Technologies <roman@ardistech.com>
   8  *
   9  * Handle basic btree node operations
  10  */
  11
  12 #include <linux/string.h>
  13 #include <linux/slab.h>
  14 #include <linux/pagemap.h>
  15 #include <linux/fs.h>
  16 #include <linux/swap.h>
  17
  18 #include "hfsplus_fs.h"
  19 #include "hfsplus_raw.h"
  20
  21 /* Copy a specified range of bytes from the raw data of a node */
  22 void hfs_bnode_read(struct hfs_bnode *node, void *buf, int off, int len)
  23 {
  24         struct page **pagep;
  25         int l;
  26
  27         off += node->page_offset;
  28         pagep = node->page + (off >> PAGE_SHIFT);
  29         off &= ~PAGE_MASK;
  30
  31         l = min_t(int, len, PAGE_SIZE - off);
  32         memcpy(buf, kmap(*pagep) + off, l);
  33         kunmap(*pagep);
  34
  35         while ((len -= l) != 0) {
  36                 buf += l;
  37                 l = min_t(int, len, PAGE_SIZE);
  38                 memcpy(buf, kmap(*++pagep), l);
  39                 kunmap(*pagep);
  40         }
  41 }
  42
  43 u16 hfs_bnode_read_u16(struct hfs_bnode *node, int off)
  44 {
  45         __be16 data;
  46         /* TODO: optimize later... */
  47         hfs_bnode_read(node, &data, off, 2);
  48         return be16_to_cpu(data);
  49 }
  50
  51 u8 hfs_bnode_read_u8(struct hfs_bnode *node, int off)
  52 {
  53         u8 data;
  54         /* TODO: optimize later... */
  55         hfs_bnode_read(node, &data, off, 1);
  56         return data;
  57 }
  58
  59 void hfs_bnode_read_key(struct hfs_bnode *node, void *key, int off)
  60 {
  61         struct hfs_btree *tree;
  62         int key_len;
  63
  64         tree = node->tree;
  65         if (node->type == HFS_NODE_LEAF ||
  66             tree->attributes & HFS_TREE_VARIDXKEYS ||
  67             node->tree->cnid == HFSPLUS_ATTR_CNID)
  68                 key_len = hfs_bnode_read_u16(node, off) + 2;
  69         else
  70                 key_len = tree->max_key_len + 2;
  71
  72         hfs_bnode_read(node, key, off, key_len);
  73 }
  74
  75 void hfs_bnode_write(struct hfs_bnode *node, void *buf, int off, int len)
  76 {
  77         struct page **pagep;
  78         int l;
  79
  80         off += node->page_offset;
  81         pagep = node->page + (off >> PAGE_SHIFT);
  82         off &= ~PAGE_MASK;
  83
  84         l = min_t(int, len, PAGE_SIZE - off);
  85         memcpy(kmap(*pagep) + off, buf, l);
  86         set_page_dirty(*pagep);
  87         kunmap(*pagep);
  88
  89         while ((len -= l) != 0) {
  90                 buf += l;
  91                 l = min_t(int, len, PAGE_SIZE);
  92                 memcpy(kmap(*++pagep), buf, l);
  93                 set_page_dirty(*pagep);
  94                 kunmap(*pagep);
  95         }
  96 }
  97
  98 void hfs_bnode_write_u16(struct hfs_bnode *node, int off, u16 data)
  99 {
 100         __be16 v = cpu_to_be16(data);
 101         /* TODO: optimize later... */
 102         hfs_bnode_write(node, &v, off, 2);
 103 }
 104
 105 void hfs_bnode_clear(struct hfs_bnode *node, int off, int len)
 106 {
 107         struct page **pagep;
 108         int l;
 109
 110         off += node->page_offset;
 111         pagep = node->page + (off >> PAGE_SHIFT);
 112         off &= ~PAGE_MASK;
 113
 114         l = min_t(int, len, PAGE_SIZE - off);
 115         memset(kmap(*pagep) + off, 0, l);
 116         set_page_dirty(*pagep);
 117         kunmap(*pagep);
 118
 119         while ((len -= l) != 0) {
 120                 l = min_t(int, len, PAGE_SIZE);
 121                 memset(kmap(*++pagep), 0, l);
 122                 set_page_dirty(*pagep);
 123                 kunmap(*pagep);
 124         }
 125 }
 126
 127 void hfs_bnode_copy(struct hfs_bnode *dst_node, int dst,
 128                     struct hfs_bnode *src_node, int src, int len)
 129 {
 130         struct hfs_btree *tree;
 131         struct page **src_page, **dst_page;
 132         int l;
 133
 134         hfs_dbg(BNODE_MOD, "copybytes: %u,%u,%u\n", dst, src, len);
 135         if (!len)
 136                 return;
 137         tree = src_node->tree;
 138         src += src_node->page_offset;
 139         dst += dst_node->page_offset;
 140         src_page = src_node->page + (src >> PAGE_SHIFT);
 141         src &= ~PAGE_MASK;
 142         dst_page = dst_node->page + (dst >> PAGE_SHIFT);
 143         dst &= ~PAGE_MASK;
 144
 145         if (src == dst) {
 146                 l = min_t(int, len, PAGE_SIZE - src);
 147                 memcpy(kmap(*dst_page) + src, kmap(*src_page) + src, l);
 148                 kunmap(*src_page);
 149                 set_page_dirty(*dst_page);
 150                 kunmap(*dst_page);
 151
 152                 while ((len -= l) != 0) {
 153                         l = min_t(int, len, PAGE_SIZE);
 154                         memcpy(kmap(*++dst_page), kmap(*++src_page), l);
 155                         kunmap(*src_page);
 156                         set_page_dirty(*dst_page);
 157                         kunmap(*dst_page);
 158                 }
 159         } else {
 160                 void *src_ptr, *dst_ptr;
 161
 162                 do {
 163                         src_ptr = kmap(*src_page) + src;
 164                         dst_ptr = kmap(*dst_page) + dst;
 165                         if (PAGE_SIZE - src < PAGE_SIZE - dst) {
 166                                 l = PAGE_SIZE - src;
 167                                 src = 0;
 168                                 dst += l;
 169                         } else {
 170                                 l = PAGE_SIZE - dst;
 171                                 src += l;
 172                                 dst = 0;
 173                         }
 174                         l = min(len, l);
 175                         memcpy(dst_ptr, src_ptr, l);
 176                         kunmap(*src_page);
 177                         set_page_dirty(*dst_page);
 178                         kunmap(*dst_page);
 179                         if (!dst)
 180                                 dst_page++;
 181                         else
 182                                 src_page++;
 183                 } while ((len -= l));
 184         }
 185 }
 186
 187 void hfs_bnode_move(struct hfs_bnode *node, int dst, int src, int len)
 188 {
 189         struct page **src_page, **dst_page;
 190         int l;
 191
 192         hfs_dbg(BNODE_MOD, "movebytes: %u,%u,%u\n", dst, src, len);
 193         if (!len)
 194                 return;
 195         src += node->page_offset;
 196         dst += node->page_offset;
 197         if (dst > src) {
 198                 src += len - 1;
 199                 src_page = node->page + (src >> PAGE_SHIFT);
 200                 src = (src & ~PAGE_MASK) + 1;
 201                 dst += len - 1;
 202                 dst_page = node->page + (dst >> PAGE_SHIFT);
 203                 dst = (dst & ~PAGE_MASK) + 1;
 204
 205                 if (src == dst) {
 206                         while (src < len) {
 207                                 memmove(kmap(*dst_page), kmap(*src_page), src);
 208                                 kunmap(*src_page);
 209                                 set_page_dirty(*dst_page);
 210                                 kunmap(*dst_page);
 211                                 len -= src;
 212                                 src = PAGE_SIZE;
 213                                 src_page--;
 214                                 dst_page--;
 215                         }
 216                         src -= len;
 217                         memmove(kmap(*dst_page) + src,
 218                                 kmap(*src_page) + src, len);
 219                         kunmap(*src_page);
 220                         set_page_dirty(*dst_page);
 221                         kunmap(*dst_page);
 222                 } else {
 223                         void *src_ptr, *dst_ptr;
 224
 225                         do {
 226                                 src_ptr = kmap(*src_page) + src;
 227                                 dst_ptr = kmap(*dst_page) + dst;
 228                                 if (src < dst) {
 229                                         l = src;
 230                                         src = PAGE_SIZE;
 231                                         dst -= l;
 232                                 } else {
 233                                         l = dst;
 234                                         src -= l;
 235                                         dst = PAGE_SIZE;
 236                                 }
 237                                 l = min(len, l);
 238                                 memmove(dst_ptr - l, src_ptr - l, l);
 239                                 kunmap(*src_page);
 240                                 set_page_dirty(*dst_page);
 241                                 kunmap(*dst_page);
 242                                 if (dst == PAGE_SIZE)
 243                                         dst_page--;
 244                                 else
 245                                         src_page--;
 246                         } while ((len -= l));
 247                 }
 248         } else {
 249                 src_page = node->page + (src >> PAGE_SHIFT);
 250                 src &= ~PAGE_MASK;
 251                 dst_page = node->page + (dst >> PAGE_SHIFT);
 252                 dst &= ~PAGE_MASK;
 253
 254                 if (src == dst) {
 255                         l = min_t(int, len, PAGE_SIZE - src);
 256                         memmove(kmap(*dst_page) + src,
 257                                 kmap(*src_page) + src, l);
 258                         kunmap(*src_page);
 259                         set_page_dirty(*dst_page);
 260                         kunmap(*dst_page);
 261
 262                         while ((len -= l) != 0) {
 263                                 l = min_t(int, len, PAGE_SIZE);
 264                                 memmove(kmap(*++dst_page),
 265                                         kmap(*++src_page), l);
 266                                 kunmap(*src_page);
 267                                 set_page_dirty(*dst_page);
 268                                 kunmap(*dst_page);
 269                         }
 270                 } else {
 271                         void *src_ptr, *dst_ptr;
 272
 273                         do {
 274                                 src_ptr = kmap(*src_page) + src;
 275                                 dst_ptr = kmap(*dst_page) + dst;
 276                                 if (PAGE_SIZE - src <
 277                                                 PAGE_SIZE - dst) {
 278                                         l = PAGE_SIZE - src;
 279                                         src = 0;
 280                                         dst += l;
 281                                 } else {
 282                                         l = PAGE_SIZE - dst;
 283                                         src += l;
 284                                         dst = 0;
 285                                 }
 286                                 l = min(len, l);
 287                                 memmove(dst_ptr, src_ptr, l);
 288                                 kunmap(*src_page);
 289                                 set_page_dirty(*dst_page);
 290                                 kunmap(*dst_page);
 291                                 if (!dst)
 292                                         dst_page++;
 293                                 else
 294                                         src_page++;
 295                         } while ((len -= l));
 296                 }
 297         }
 298 }
 299
 300 void hfs_bnode_dump(struct hfs_bnode *node)
 301 {
 302         struct hfs_bnode_desc desc;
 303         __be32 cnid;
 304         int i, off, key_off;
 305
 306         hfs_dbg(BNODE_MOD, "bnode: %d\n", node->this);
 307         hfs_bnode_read(node, &desc, 0, sizeof(desc));
 308         hfs_dbg(BNODE_MOD, "%d, %d, %d, %d, %d\n",
 309                 be32_to_cpu(desc.next), be32_to_cpu(desc.prev),
 310                 desc.type, desc.height, be16_to_cpu(desc.num_recs));
 311
 312         off = node->tree->node_size - 2;
 313         for (i = be16_to_cpu(desc.num_recs); i >= 0; off -= 2, i--) {
 314                 key_off = hfs_bnode_read_u16(node, off);
 315                 hfs_dbg(BNODE_MOD, " %d", key_off);
 316                 if (i && node->type == HFS_NODE_INDEX) {
 317                         int tmp;
 318
 319                         if (node->tree->attributes & HFS_TREE_VARIDXKEYS ||
 320                                         node->tree->cnid == HFSPLUS_ATTR_CNID)
 321                                 tmp = hfs_bnode_read_u16(node, key_off) + 2;
 322                         else
 323                                 tmp = node->tree->max_key_len + 2;
 324                         hfs_dbg_cont(BNODE_MOD, " (%d", tmp);
 325                         hfs_bnode_read(node, &cnid, key_off + tmp, 4);
 326                         hfs_dbg_cont(BNODE_MOD, ",%d)", be32_to_cpu(cnid));
 327                 } else if (i && node->type == HFS_NODE_LEAF) {
 328                         int tmp;
 329
 330                         tmp = hfs_bnode_read_u16(node, key_off);
 331                         hfs_dbg_cont(BNODE_MOD, " (%d)", tmp);
 332                 }
 333         }
 334         hfs_dbg_cont(BNODE_MOD, "\n");
 335 }
 336
 337 void hfs_bnode_unlink(struct hfs_bnode *node)
 338 {
 339         struct hfs_btree *tree;
 340         struct hfs_bnode *tmp;
 341         __be32 cnid;
 342
 343         tree = node->tree;
 344         if (node->prev) {
 345                 tmp = hfs_bnode_find(tree, node->prev);
 346                 if (IS_ERR(tmp))
 347                         return;
 348                 tmp->next = node->next;
 349                 cnid = cpu_to_be32(tmp->next);
 350                 hfs_bnode_write(tmp, &cnid,
 351                         offsetof(struct hfs_bnode_desc, next), 4);
 352                 hfs_bnode_put(tmp);
 353         } else if (node->type == HFS_NODE_LEAF)
 354                 tree->leaf_head = node->next;
 355
 356         if (node->next) {
 357                 tmp = hfs_bnode_find(tree, node->next);
 358                 if (IS_ERR(tmp))
 359                         return;
 360                 tmp->prev = node->prev;
 361                 cnid = cpu_to_be32(tmp->prev);
 362                 hfs_bnode_write(tmp, &cnid,
 363                         offsetof(struct hfs_bnode_desc, prev), 4);
 364                 hfs_bnode_put(tmp);
 365         } else if (node->type == HFS_NODE_LEAF)
 366                 tree->leaf_tail = node->prev;
 367
 368         /* move down? */
 369         if (!node->prev && !node->next)
 370                 hfs_dbg(BNODE_MOD, "hfs_btree_del_level\n");
 371         if (!node->parent) {
 372                 tree->root = 0;
 373                 tree->depth = 0;
 374         }
 375         set_bit(HFS_BNODE_DELETED, &node->flags);
 376 }
 377
 378 static inline int hfs_bnode_hash(u32 num)
 379 {
 380         num = (num >> 16) + num;
 381         num += num >> 8;
 382         return num & (NODE_HASH_SIZE - 1);
 383 }
 384
 385 struct hfs_bnode *hfs_bnode_findhash(struct hfs_btree *tree, u32 cnid)
 386 {
 387         struct hfs_bnode *node;
 388
 389         if (cnid >= tree->node_count) {
 390                 pr_err("request for non-existent node %d in B*Tree\n",
 391                        cnid);
 392                 return NULL;
 393         }
 394
 395         for (node = tree->node_hash[hfs_bnode_hash(cnid)];
 396                         node; node = node->next_hash)
 397                 if (node->this == cnid)
 398                         return node;
 399         return NULL;
 400 }
 401
 402 static struct hfs_bnode *__hfs_bnode_create(struct hfs_btree *tree, u32 cnid)
 403 {
 404         struct super_block *sb;
 405         struct hfs_bnode *node, *node2;
 406         struct address_space *mapping;
 407         struct page *page;
 408         int size, block, i, hash;
 409         loff_t off;
 410
 411         if (cnid >= tree->node_count) {
 412                 pr_err("request for non-existent node %d in B*Tree\n",
 413                        cnid);
 414                 return NULL;
 415         }
 416
 417         sb = tree->inode->i_sb;
 418         size = sizeof(struct hfs_bnode) + tree->pages_per_bnode *
 419                 sizeof(struct page *);
 420         node = kzalloc(size, GFP_KERNEL);
 421         if (!node)
 422                 return NULL;
 423         node->tree = tree;
 424         node->this = cnid;
 425         set_bit(HFS_BNODE_NEW, &node->flags);
 426         atomic_set(&node->refcnt, 1);
 427         hfs_dbg(BNODE_REFS, "new_node(%d:%d): 1\n",
 428                 node->tree->cnid, node->this);
 429         init_waitqueue_head(&node->lock_wq);
 430         spin_lock(&tree->hash_lock);
 431         node2 = hfs_bnode_findhash(tree, cnid);
 432         if (!node2) {
 433                 hash = hfs_bnode_hash(cnid);
 434                 node->next_hash = tree->node_hash[hash];
 435                 tree->node_hash[hash] = node;
 436                 tree->node_hash_cnt++;
 437         } else {
 438                 spin_unlock(&tree->hash_lock);
 439                 kfree(node);
 440                 wait_event(node2->lock_wq,
 441                         !test_bit(HFS_BNODE_NEW, &node2->flags));
 442                 return node2;
 443         }
 444         spin_unlock(&tree->hash_lock);
 445
 446         mapping = tree->inode->i_mapping;
 447         off = (loff_t)cnid << tree->node_size_shift;
 448         block = off >> PAGE_SHIFT;
 449         node->page_offset = off & ~PAGE_MASK;
 450         for (i = 0; i < tree->pages_per_bnode; block++, i++) {
 451                 page = read_mapping_page(mapping, block, NULL);
 452                 if (IS_ERR(page))
 453                         goto fail;
 454                 if (PageError(page)) {
 455                         put_page(page);
 456                         goto fail;
 457                 }
 458                 node->page[i] = page;
 459         }
 460
 461         return node;
 462 fail:
 463         set_bit(HFS_BNODE_ERROR, &node->flags);
 464         return node;
 465 }
 466
 467 void hfs_bnode_unhash(struct hfs_bnode *node)
 468 {
 469         struct hfs_bnode **p;
 470
 471         hfs_dbg(BNODE_REFS, "remove_node(%d:%d): %d\n",
 472                 node->tree->cnid, node->this, atomic_read(&node->refcnt));
 473         for (p = &node->tree->node_hash[hfs_bnode_hash(node->this)];
 474              *p && *p != node; p = &(*p)->next_hash)
 475                 ;
 476         BUG_ON(!*p);
 477         *p = node->next_hash;
 478         node->tree->node_hash_cnt--;
 479 }
 480
 481 /* Load a particular node out of a tree */
 482 struct hfs_bnode *hfs_bnode_find(struct hfs_btree *tree, u32 num)
 483 {
 484         struct hfs_bnode *node;
 485         struct hfs_bnode_desc *desc;
 486         int i, rec_off, off, next_off;
 487         int entry_size, key_size;
 488
 489         spin_lock(&tree->hash_lock);
 490         node = hfs_bnode_findhash(tree, num);
 491         if (node) {
 492                 hfs_bnode_get(node);
 493                 spin_unlock(&tree->hash_lock);
 494                 wait_event(node->lock_wq,
 495                         !test_bit(HFS_BNODE_NEW, &node->flags));
 496                 if (test_bit(HFS_BNODE_ERROR, &node->flags))
 497                         goto node_error;
 498                 return node;
 499         }
 500         spin_unlock(&tree->hash_lock);
 501         node = __hfs_bnode_create(tree, num);
 502         if (!node)
 503                 return ERR_PTR(-ENOMEM);
 504         if (test_bit(HFS_BNODE_ERROR, &node->flags))
 505                 goto node_error;
 506         if (!test_bit(HFS_BNODE_NEW, &node->flags))
 507                 return node;
 508
 509         desc = (struct hfs_bnode_desc *)(kmap(node->page[0]) +
 510                         node->page_offset);
 511         node->prev = be32_to_cpu(desc->prev);
 512         node->next = be32_to_cpu(desc->next);
 513         node->num_recs = be16_to_cpu(desc->num_recs);
 514         node->type = desc->type;
 515         node->height = desc->height;
 516         kunmap(node->page[0]);
 517
 518         switch (node->type) {
 519         case HFS_NODE_HEADER:
 520         case HFS_NODE_MAP:
 521                 if (node->height != 0)
 522                         goto node_error;
 523                 break;
 524         case HFS_NODE_LEAF:
 525                 if (node->height != 1)
 526                         goto node_error;
 527                 break;
 528         case HFS_NODE_INDEX:
 529                 if (node->height <= 1 || node->height > tree->depth)
 530                         goto node_error;
 531                 break;
 532         default:
 533                 goto node_error;
 534         }
 535
 536         rec_off = tree->node_size - 2;
 537         off = hfs_bnode_read_u16(node, rec_off);
 538         if (off != sizeof(struct hfs_bnode_desc))
 539                 goto node_error;
 540         for (i = 1; i <= node->num_recs; off = next_off, i++) {
 541                 rec_off -= 2;
 542                 next_off = hfs_bnode_read_u16(node, rec_off);
 543                 if (next_off <= off ||
 544                     next_off > tree->node_size ||
 545                     next_off & 1)
 546                         goto node_error;
 547                 entry_size = next_off - off;
 548                 if (node->type != HFS_NODE_INDEX &&
 549                     node->type != HFS_NODE_LEAF)
 550                         continue;
 551                 key_size = hfs_bnode_read_u16(node, off) + 2;
 552                 if (key_size >= entry_size || key_size & 1)
 553                         goto node_error;
 554         }
 555         clear_bit(HFS_BNODE_NEW, &node->flags);
 556         wake_up(&node->lock_wq);
 557         return node;
 558
 559 node_error:
 560         set_bit(HFS_BNODE_ERROR, &node->flags);
 561         clear_bit(HFS_BNODE_NEW, &node->flags);
 562         wake_up(&node->lock_wq);
 563         hfs_bnode_put(node);
 564         return ERR_PTR(-EIO);
 565 }
 566
 567 void hfs_bnode_free(struct hfs_bnode *node)
 568 {
 569         int i;
 570
 571         for (i = 0; i < node->tree->pages_per_bnode; i++)
 572                 if (node->page[i])
 573                         put_page(node->page[i]);
 574         kfree(node);
 575 }
 576
 577 struct hfs_bnode *hfs_bnode_create(struct hfs_btree *tree, u32 num)
 578 {
 579         struct hfs_bnode *node;
 580         struct page **pagep;
 581         int i;
 582
 583         spin_lock(&tree->hash_lock);
 584         node = hfs_bnode_findhash(tree, num);
 585         spin_unlock(&tree->hash_lock);
 586         if (node) {
 587                 pr_crit("new node %u already hashed?\n", num);
 588                 WARN_ON(1);
 589                 return node;
 590         }
 591         node = __hfs_bnode_create(tree, num);
 592         if (!node)
 593                 return ERR_PTR(-ENOMEM);
 594         if (test_bit(HFS_BNODE_ERROR, &node->flags)) {
 595                 hfs_bnode_put(node);
 596                 return ERR_PTR(-EIO);
 597         }
 598
 599         pagep = node->page;
 600         memset(kmap(*pagep) + node->page_offset, 0,
 601                min_t(int, PAGE_SIZE, tree->node_size));
 602         set_page_dirty(*pagep);
 603         kunmap(*pagep);
 604         for (i = 1; i < tree->pages_per_bnode; i++) {
 605                 memset(kmap(*++pagep), 0, PAGE_SIZE);
 606                 set_page_dirty(*pagep);
 607                 kunmap(*pagep);
 608         }
 609         clear_bit(HFS_BNODE_NEW, &node->flags);
 610         wake_up(&node->lock_wq);
 611
 612         return node;
 613 }
 614
 615 void hfs_bnode_get(struct hfs_bnode *node)
 616 {
 617         if (node) {
 618                 atomic_inc(&node->refcnt);
 619                 hfs_dbg(BNODE_REFS, "get_node(%d:%d): %d\n",
 620                         node->tree->cnid, node->this,
 621                         atomic_read(&node->refcnt));
 622         }
 623 }
 624
 625 /* Dispose of resources used by a node */
 626 void hfs_bnode_put(struct hfs_bnode *node)
 627 {
 628         if (node) {
 629                 struct hfs_btree *tree = node->tree;
 630                 int i;
 631
 632                 hfs_dbg(BNODE_REFS, "put_node(%d:%d): %d\n",
 633                         node->tree->cnid, node->this,
 634                         atomic_read(&node->refcnt));
 635                 BUG_ON(!atomic_read(&node->refcnt));
 636                 if (!atomic_dec_and_lock(&node->refcnt, &tree->hash_lock))
 637                         return;
 638                 for (i = 0; i < tree->pages_per_bnode; i++) {
 639                         if (!node->page[i])
 640                                 continue;
 641                         mark_page_accessed(node->page[i]);
 642                 }
 643
 644                 if (test_bit(HFS_BNODE_DELETED, &node->flags)) {
 645                         hfs_bnode_unhash(node);
 646                         spin_unlock(&tree->hash_lock);
 647                         if (hfs_bnode_need_zeroout(tree))
 648                                 hfs_bnode_clear(node, 0, tree->node_size);
 649                         hfs_bmap_free(node);
 650                         hfs_bnode_free(node);
 651                         return;
 652                 }
 653                 spin_unlock(&tree->hash_lock);
 654         }
 655 }
 656
 657 /*
 658  * Unused nodes have to be zeroed if this is the catalog tree and
 659  * a corresponding flag in the volume header is set.
 660  */
 661 bool hfs_bnode_need_zeroout(struct hfs_btree *tree)
 662 {
 663         struct super_block *sb = tree->inode->i_sb;
 664         struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
 665         const u32 volume_attr = be32_to_cpu(sbi->s_vhdr->attributes);
 666
 667         return tree->cnid == HFSPLUS_CAT_CNID &&
 668                 volume_attr & HFSPLUS_VOL_UNUSED_NODE_FIX;
 669 }