lwext4/ext4_xattr.c

   1 /*
   2  * Copyright (c) 2015 Grzegorz Kostka (kostka.grzegorz@gmail.com)
   3  * Copyright (c) 2015 Kaho Ng (ngkaho1234@gmail.com)
   4  *
   5  *
   6  * HelenOS:
   7  * Copyright (c) 2012 Martin Sucha
   8  * Copyright (c) 2012 Frantisek Princ
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  *
  15  * - Redistributions of source code must retain the above copyright
  16  *   notice, this list of conditions and the following disclaimer.
  17  * - Redistributions in binary form must reproduce the above copyright
  18  *   notice, this list of conditions and the following disclaimer in the
  19  *   documentation and/or other materials provided with the distribution.
  20  * - The name of the author may not be used to endorse or promote products
  21  *   derived from this software without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  25  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  26  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  27  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  28  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  29  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  30  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  32  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  33  */
  34
  35 /** @addtogroup lwext4
  36  * @{
  37  */
  38 /**
  39  * @file  ext4_xattr.c
  40  * @brief Extended Attribute manipulation.
  41  */
  42
  43 #include "ext4_config.h"
  44 #include "ext4_types.h"
  45 #include "ext4_fs.h"
  46 #include "ext4_errno.h"
  47 #include "ext4_blockdev.h"
  48 #include "ext4_super.h"
  49 #include "ext4_debug.h"
  50 #include "ext4_block_group.h"
  51 #include "ext4_balloc.h"
  52 #include "ext4_inode.h"
  53 #include "ext4_extent.h"
  54
  55 #include <string.h>
  56 #include <stdlib.h>
  57
  58 /**
  59  * @file  ext4_xattr.c
  60  * @brief Extended Attribute Manipulation
  61  */
  62
  63 #define NAME_HASH_SHIFT 5
  64 #define VALUE_HASH_SHIFT 16
  65
  66 static inline void
  67 ext4_xattr_compute_hash(struct ext4_xattr_header *header,
  68                         struct ext4_xattr_entry *entry)
  69 {
  70         uint32_t hash = 0;
  71         char *name = EXT4_XATTR_NAME(entry);
  72         int n;
  73
  74         for (n = 0; n < entry->e_name_len; n++) {
  75                 hash = (hash << NAME_HASH_SHIFT) ^
  76                         (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
  77                         *name++;
  78         }
  79
  80         if (entry->e_value_block == 0 && entry->e_value_size != 0) {
  81                 uint32_t *value = (uint32_t *)((char *)header +
  82                                 to_le16(entry->e_value_offs));
  83                 for (n = (to_le32(entry->e_value_size) +
  84                                         EXT4_XATTR_ROUND) >> EXT4_XATTR_PAD_BITS; n; n--) {
  85                         hash = (hash << VALUE_HASH_SHIFT) ^
  86                                 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
  87                                 to_le32(*value++);
  88                 }
  89         }
  90         entry->e_hash = to_le32(hash);
  91 }
  92
  93 #define BLOCK_HASH_SHIFT 16
  94
  95 /*
  96  * ext4_xattr_rehash()
  97  *
  98  * Re-compute the extended attribute hash value after an entry has changed.
  99  */
 100 static void ext4_xattr_rehash(struct ext4_xattr_header *header,
 101                               struct ext4_xattr_entry *entry)
 102 {
 103         struct ext4_xattr_entry *here;
 104         uint32_t hash = 0;
 105
 106         ext4_xattr_compute_hash(header, entry);
 107         here = EXT4_XATTR_ENTRY(header+1);
 108         while (!EXT4_XATTR_IS_LAST_ENTRY(here)) {
 109                 if (!here->e_hash) {
 110                         /* Block is not shared if an entry's hash value == 0 */
 111                         hash = 0;
 112                         break;
 113                 }
 114                 hash = (hash << BLOCK_HASH_SHIFT) ^
 115                        (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
 116                        to_le32(here->e_hash);
 117                 here = EXT4_XATTR_NEXT(here);
 118         }
 119         header->h_hash = to_le32(hash);
 120 }
 121
 122 static int ext4_xattr_item_cmp(struct ext4_xattr_item *a,
 123                                 struct ext4_xattr_item *b)
 124 {
 125         int result;
 126         result = a->name_index - b->name_index;
 127         if (result)
 128                 return result;
 129
 130         result = a->name_len - b->name_len;
 131         if (result)
 132                 return result;
 133
 134         return memcmp(a->name, b->name, a->name_len);
 135 }
 136
 137 RB_GENERATE_INTERNAL(ext4_xattr_tree,
 138                      ext4_xattr_item,
 139                      node,
 140                      ext4_xattr_item_cmp,
 141                      static inline)
 142
 143 static struct ext4_xattr_item *
 144 ext4_xattr_item_alloc(uint8_t name_index,
 145                       char   *name,
 146                       size_t  name_len)
 147 {
 148         struct ext4_xattr_item *item;
 149         item = malloc(sizeof(struct ext4_xattr_item) +
 150                         name_len);
 151         if (!item)
 152                 return NULL;
 153
 154         item->name_index = name_index;
 155         item->name       = (char *)(item + 1);
 156         item->name_len   = name_len;
 157         item->data       = NULL;
 158         item->data_size  = 0;
 159
 160         memset(&item->node, 0, sizeof(item->node));
 161         memcpy(item->name, name, name_len);
 162
 163         return item;
 164 }
 165
 166 static int
 167 ext4_xattr_item_alloc_data(struct ext4_xattr_item *item,
 168                            void *orig_data,
 169                            size_t data_size)
 170 {
 171         void *data = NULL;
 172         ext4_assert(!item->data);
 173         data = malloc(data_size);
 174         if (!data)
 175                 return ENOMEM;
 176
 177         if (orig_data)
 178                 memcpy(data, orig_data, data_size);
 179
 180         item->data = data;
 181         item->data_size = data_size;
 182         return EOK;
 183 }
 184
 185 static void
 186 ext4_xattr_item_free_data(struct ext4_xattr_item *item)
 187 {
 188         ext4_assert(item->data);
 189         free(item->data);
 190         item->data = NULL;
 191         item->data_size = 0;
 192 }
 193
 194 static int
 195 ext4_xattr_item_resize_data(struct ext4_xattr_item *item,
 196                             size_t new_data_size)
 197 {
 198         if (new_data_size != item->data_size) {
 199                 void *new_data;
 200                 new_data = realloc(item->data, new_data_size);
 201                 if (!new_data)
 202                         return ENOMEM;
 203
 204                 item->data = new_data;
 205                 item->data_size = new_data_size;
 206         }
 207         return EOK;
 208 }
 209
 210 static void
 211 ext4_xattr_item_free(struct ext4_xattr_item *item)
 212 {
 213         if (item->data)
 214                 ext4_xattr_item_free_data(item);
 215
 216         free(item);
 217 }
 218
 219
 220 static void *ext4_xattr_entry_data(struct ext4_xattr_ref *xattr_ref,
 221                                    struct ext4_xattr_entry *entry,
 222                                    bool in_inode)
 223 {
 224         void *ret;
 225         if (in_inode) {
 226                 struct ext4_xattr_ibody_header *header;
 227                 struct ext4_xattr_entry *first_entry;
 228                 uint16_t inode_size = ext4_get16(&xattr_ref->fs->sb,
 229                                                  inode_size);
 230                 header = EXT4_XATTR_IHDR(xattr_ref->inode_ref->inode);
 231                 first_entry = EXT4_XATTR_IFIRST(header);
 232
 233                 ret = (void *)((char *)first_entry + to_le16(entry->e_value_offs));
 234                 if ((char *)ret + EXT4_XATTR_SIZE(to_le32(entry->e_value_size))
 235                         - (char *)xattr_ref->inode_ref->inode >
 236                     inode_size)
 237                         ret = NULL;
 238
 239         } else {
 240                 int32_t block_size =
 241                         ext4_sb_get_block_size(&xattr_ref->fs->sb);
 242                 ret = (void *)((char *)xattr_ref->block.data +
 243                                 to_le16(entry->e_value_offs));
 244                 if ((char *)ret + EXT4_XATTR_SIZE(to_le32(entry->e_value_size))
 245                         - (char *)xattr_ref->block.data >
 246                     block_size)
 247                         ret = NULL;
 248         }
 249         return ret;
 250 }
 251
 252 static int ext4_xattr_block_fetch(struct ext4_xattr_ref *xattr_ref)
 253 {
 254         int ret = EOK;
 255         size_t size_rem;
 256         void *data;
 257         struct ext4_xattr_entry *entry = NULL;
 258
 259         ext4_assert(xattr_ref->block.data);
 260         entry = EXT4_XATTR_BFIRST(&xattr_ref->block);
 261
 262         size_rem = ext4_sb_get_block_size(&xattr_ref->fs->sb);
 263         for(;size_rem > 0 && !EXT4_XATTR_IS_LAST_ENTRY(entry);
 264             entry = EXT4_XATTR_NEXT(entry),
 265             size_rem -= EXT4_XATTR_LEN(entry->e_name_len)) {
 266                 struct ext4_xattr_item *item;
 267                 char *e_name = EXT4_XATTR_NAME(entry);
 268
 269                 data = ext4_xattr_entry_data(xattr_ref, entry,
 270                                              false);
 271                 if (!data) {
 272                         ret = EIO;
 273                         goto Finish;
 274                 }
 275
 276                 item = ext4_xattr_item_alloc(entry->e_name_index,
 277                                              e_name,
 278                                              (size_t)entry->e_name_len);
 279                 if (!item) {
 280                         ret = ENOMEM;
 281                         goto Finish;
 282                 }
 283                 if (ext4_xattr_item_alloc_data(item,
 284                                                data,
 285                                                to_le32(entry->e_value_size))
 286                         != EOK) {
 287                         ext4_xattr_item_free(item);
 288                         ret = ENOMEM;
 289                         goto Finish;
 290                 }
 291                 RB_INSERT(ext4_xattr_tree, &xattr_ref->root, item);
 292                 xattr_ref->ea_size += EXT4_XATTR_SIZE(item->data_size) +
 293                                         EXT4_XATTR_LEN(item->name_len);
 294         }
 295
 296 Finish:
 297         return ret;
 298 }
 299
 300 static int ext4_xattr_inode_fetch(struct ext4_xattr_ref *xattr_ref)
 301 {
 302         void *data;
 303         size_t size_rem;
 304         int ret = EOK;
 305         struct ext4_xattr_ibody_header *header = NULL;
 306         struct ext4_xattr_entry *entry = NULL;
 307         uint16_t inode_size = ext4_get16(&xattr_ref->fs->sb,
 308                                          inode_size);
 309
 310         header = EXT4_XATTR_IHDR(xattr_ref->inode_ref->inode);
 311         entry = EXT4_XATTR_IFIRST(header);
 312
 313         size_rem = inode_size -
 314                 EXT4_GOOD_OLD_INODE_SIZE -
 315                 xattr_ref->inode_ref->inode->extra_isize;
 316         for(;size_rem > 0 && !EXT4_XATTR_IS_LAST_ENTRY(entry);
 317             entry = EXT4_XATTR_NEXT(entry),
 318             size_rem -= EXT4_XATTR_LEN(entry->e_name_len)) {
 319                 struct ext4_xattr_item *item;
 320                 char *e_name = EXT4_XATTR_NAME(entry);
 321
 322                 data = ext4_xattr_entry_data(xattr_ref, entry,
 323                                              true);
 324                 if (!data) {
 325                         ret = EIO;
 326                         goto Finish;
 327                 }
 328
 329                 item = ext4_xattr_item_alloc(entry->e_name_index,
 330                                              e_name,
 331                                              (size_t)entry->e_name_len);
 332                 if (!item) {
 333                         ret = ENOMEM;
 334                         goto Finish;
 335                 }
 336                 if (ext4_xattr_item_alloc_data(item,
 337                                                data,
 338                                                to_le32(entry->e_value_size))
 339                         != EOK) {
 340                         ext4_xattr_item_free(item);
 341                         ret = ENOMEM;
 342                         goto Finish;
 343                 }
 344                 RB_INSERT(ext4_xattr_tree, &xattr_ref->root, item);
 345                 xattr_ref->ea_size += EXT4_XATTR_SIZE(item->data_size) +
 346                                         EXT4_XATTR_LEN(item->name_len);
 347         }
 348
 349 Finish:
 350         return ret;
 351 }
 352
 353
 354 static size_t
 355 ext4_xattr_inode_space(struct ext4_xattr_ref *xattr_ref)
 356 {
 357         uint16_t inode_size = ext4_get16(&xattr_ref->fs->sb,
 358                                          inode_size);
 359         uint16_t size_rem = inode_size -
 360                         EXT4_GOOD_OLD_INODE_SIZE -
 361                         xattr_ref->inode_ref->inode->extra_isize;
 362         return size_rem;
 363 }
 364
 365 static size_t
 366 ext4_xattr_block_space(struct ext4_xattr_ref *xattr_ref)
 367 {
 368         return ext4_sb_get_block_size(&xattr_ref->fs->sb);
 369 }
 370
 371 static int ext4_xattr_fetch(struct ext4_xattr_ref *xattr_ref)
 372 {
 373         int ret = EOK;
 374         uint16_t inode_size = ext4_get16(&xattr_ref->fs->sb,
 375                                          inode_size);
 376         if (inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
 377                 ret = ext4_xattr_inode_fetch(xattr_ref);
 378                 if (ret != EOK)
 379                         return ret;
 380
 381         }
 382
 383         if (xattr_ref->block_loaded)
 384                 ret = ext4_xattr_block_fetch(xattr_ref);
 385
 386         xattr_ref->dirty = false;
 387         return ret;
 388 }
 389
 390 static struct ext4_xattr_item *
 391 ext4_xattr_lookup_item(struct ext4_xattr_ref *xattr_ref,
 392                        uint8_t name_index,
 393                        char   *name,
 394                        size_t  name_len)
 395 {
 396         struct ext4_xattr_item tmp, *ret;
 397         tmp.name_index = name_index;
 398         tmp.name       = name;
 399         tmp.name_len   = name_len;
 400         ret = RB_FIND(ext4_xattr_tree, &xattr_ref->root,
 401                         &tmp);
 402         return ret;
 403 }
 404
 405 static struct ext4_xattr_item *
 406 ext4_xattr_insert_item(struct ext4_xattr_ref *xattr_ref,
 407                        uint8_t name_index,
 408                        char   *name,
 409                        size_t  name_len,
 410                        void   *data,
 411                        size_t  data_size)
 412 {
 413         struct ext4_xattr_item *item;
 414         item = ext4_xattr_item_alloc(name_index,
 415                                      name,
 416                                      name_len);
 417         if (!item)
 418                 return NULL;
 419
 420         if (xattr_ref->ea_size + EXT4_XATTR_SIZE(item->data_size) +
 421                                 EXT4_XATTR_LEN(item->name_len) >
 422                 ext4_xattr_inode_space(xattr_ref) +
 423                 ext4_xattr_block_space(xattr_ref)) {
 424                 ext4_xattr_item_free(item);
 425                 return NULL;
 426         }
 427         if (ext4_xattr_item_alloc_data(item,
 428                                        data,
 429                                        data_size) != EOK) {
 430                 ext4_xattr_item_free(item);
 431                 return NULL;
 432         }
 433         RB_INSERT(ext4_xattr_tree, &xattr_ref->root, item);
 434         xattr_ref->ea_size += EXT4_XATTR_SIZE(item->data_size) +
 435                                 EXT4_XATTR_LEN(item->name_len);
 436         xattr_ref->dirty = true;
 437         return item;
 438 }
 439
 440 static int
 441 ext4_xattr_remove_item(struct ext4_xattr_ref *xattr_ref,
 442                        uint8_t name_index,
 443                        char   *name,
 444                        size_t  name_len)
 445 {
 446         int ret = ENOENT;
 447         struct ext4_xattr_item *item =
 448                 ext4_xattr_lookup_item(xattr_ref,
 449                                        name_index,
 450                                        name,
 451                                        name_len);
 452         if (item) {
 453                 RB_REMOVE(ext4_xattr_tree, &xattr_ref->root, item);
 454                 ext4_xattr_item_free(item);
 455                 xattr_ref->ea_size -= EXT4_XATTR_SIZE(item->data_size) +
 456                                         EXT4_XATTR_LEN(item->name_len);
 457                 xattr_ref->dirty = true;
 458                 ret = EOK;
 459         }
 460         return ret;
 461 }
 462
 463 static int
 464 ext4_xattr_resize_item(struct ext4_xattr_ref *xattr_ref,
 465                        struct ext4_xattr_item *item,
 466                        size_t new_data_size)
 467 {
 468         int ret = EOK;
 469         if (xattr_ref->ea_size - EXT4_XATTR_SIZE(item->data_size) +
 470                                 EXT4_XATTR_SIZE(new_data_size) >
 471                 ext4_xattr_inode_space(xattr_ref) +
 472                 ext4_xattr_block_space(xattr_ref)) {
 473
 474                 return ENOSPC;
 475         }
 476         ret = ext4_xattr_item_resize_data(item,
 477                                           new_data_size);
 478         if (ret != EOK) {
 479                 return ret;
 480         }
 481         xattr_ref->ea_size -= EXT4_XATTR_SIZE(item->data_size) +
 482                                 EXT4_XATTR_SIZE(new_data_size);
 483         xattr_ref->dirty = true;
 484         return ret;
 485 }
 486
 487 static void
 488 ext4_xattr_purge_items(struct ext4_xattr_ref *xattr_ref)
 489 {
 490         struct ext4_xattr_item *item, *save_item;
 491         uint64_t xattr_block = ext4_inode_get_file_acl(xattr_ref->inode_ref->inode,
 492                                               &xattr_ref->fs->sb);
 493         RB_FOREACH_SAFE(item,
 494                         ext4_xattr_tree,
 495                         &xattr_ref->root,
 496                         save_item) {
 497                 RB_REMOVE(ext4_xattr_tree, &xattr_ref->root, item);
 498                 ext4_xattr_item_free(item);
 499         }
 500         xattr_ref->ea_size = 0;
 501         if (xattr_block)
 502                 xattr_ref->ea_size += sizeof(struct ext4_xattr_header);
 503
 504         if (ext4_xattr_inode_space(xattr_ref) >
 505             sizeof(struct ext4_xattr_ibody_header))
 506                 xattr_ref->ea_size += sizeof(struct ext4_xattr_ibody_header);
 507 }
 508
 509
 510 static int
 511 ext4_xattr_try_alloc_block(struct ext4_xattr_ref *xattr_ref)
 512 {
 513         int ret = EOK;
 514
 515         uint64_t xattr_block = 0;
 516         xattr_block = ext4_inode_get_file_acl(xattr_ref->inode_ref->inode,
 517                                               &xattr_ref->fs->sb);
 518         if (!xattr_block) {
 519                 ret = ext4_balloc_alloc_block(xattr_ref->inode_ref,
 520                                 (uint32_t *)&xattr_block);
 521                 if (ret != EOK)
 522                         goto Finish;
 523
 524                 ret = ext4_block_get(xattr_ref->fs->bdev,
 525                                 &xattr_ref->block,
 526                                 xattr_block);
 527                 if (ret != EOK) {
 528                         ext4_balloc_free_block(xattr_ref->inode_ref,
 529                                         xattr_block);
 530                         goto Finish;
 531                 }
 532
 533                 ext4_inode_set_file_acl(xattr_ref->inode_ref->inode,
 534                                         &xattr_ref->fs->sb,
 535                                         xattr_block);
 536                 xattr_ref->inode_ref->dirty = true;
 537                 xattr_ref->block_loaded = true;
 538                 xattr_ref->ea_size += sizeof(struct ext4_xattr_header);
 539         }
 540
 541 Finish:
 542         return ret;
 543 }
 544
 545 static void
 546 ext4_xattr_try_free_block(struct ext4_xattr_ref *xattr_ref)
 547 {
 548         uint64_t xattr_block;
 549         xattr_block =
 550                 ext4_inode_get_file_acl(xattr_ref->inode_ref->inode,
 551                                 &xattr_ref->fs->sb);
 552         ext4_inode_set_file_acl(xattr_ref->inode_ref->inode,
 553                         &xattr_ref->fs->sb,
 554                         0);
 555         ext4_block_set(xattr_ref->fs->bdev,
 556                         &xattr_ref->block);
 557         ext4_balloc_free_block(xattr_ref->inode_ref,
 558                         xattr_block);
 559         xattr_ref->inode_ref->dirty = true;
 560         xattr_ref->block_loaded = false;
 561         xattr_ref->ea_size -= sizeof(struct ext4_xattr_header);
 562
 563 }
 564
 565 static void
 566 ext4_xattr_set_block_header(struct ext4_xattr_ref *xattr_ref)
 567 {
 568         struct ext4_xattr_header *block_header = NULL;
 569         block_header = EXT4_XATTR_BHDR(&xattr_ref->block);
 570
 571         memset(block_header, 0, sizeof(struct ext4_xattr_header));
 572         block_header->h_magic = EXT4_XATTR_MAGIC;
 573         block_header->h_refcount = to_le32(1);
 574         block_header->h_blocks = to_le32(1);
 575 }
 576
 577 static int
 578 ext4_xattr_write_to_disk(struct ext4_xattr_ref *xattr_ref)
 579 {
 580         int ret = EOK;
 581         bool block_modified = false;
 582         void *ibody_data, *block_data;
 583         struct ext4_xattr_item *item, *save_item;
 584         size_t inode_size_rem, block_size_rem;
 585         struct ext4_xattr_ibody_header *ibody_header = NULL;
 586         struct ext4_xattr_header *block_header = NULL;
 587         struct ext4_xattr_entry *entry = NULL;
 588         struct ext4_xattr_entry *block_entry = NULL;
 589
 590         inode_size_rem = ext4_xattr_inode_space(xattr_ref);
 591         block_size_rem = ext4_xattr_block_space(xattr_ref);
 592         if (inode_size_rem > sizeof(struct ext4_xattr_ibody_header)) {
 593                 ibody_header = EXT4_XATTR_IHDR(xattr_ref->inode_ref->inode);
 594                 entry = EXT4_XATTR_IFIRST(ibody_header);
 595         }
 596
 597         if (xattr_ref->dirty) {
 598                 /* If there are enough spaces in the ibody EA table.*/
 599                 if (inode_size_rem > sizeof(struct ext4_xattr_ibody_header)) {
 600                         memset(ibody_header, 0, inode_size_rem);
 601                         ibody_header->h_magic = EXT4_XATTR_MAGIC;
 602                         ibody_data = (char *)ibody_header + inode_size_rem;
 603                         inode_size_rem -= sizeof(struct ext4_xattr_ibody_header);
 604
 605                         xattr_ref->inode_ref->dirty = true;
 606                 }
 607                 /* If we need an extra block to hold the EA entries*/
 608                 if (xattr_ref->ea_size > inode_size_rem) {
 609                         if (!xattr_ref->block_loaded) {
 610                                 ret = ext4_xattr_try_alloc_block(xattr_ref);
 611                                 if (ret != EOK)
 612                                         goto Finish;
 613
 614                         }
 615                         block_header = EXT4_XATTR_BHDR(&xattr_ref->block);
 616                         block_entry = EXT4_XATTR_BFIRST(&xattr_ref->block);
 617                         ext4_xattr_set_block_header(xattr_ref);
 618                         block_data = (char *)block_header + block_size_rem;
 619                         block_size_rem -= sizeof(struct ext4_xattr_header);
 620
 621                         xattr_ref->block.dirty = true;
 622                 } else {
 623                         /* We don't need an extra block.*/
 624                         if (xattr_ref->block_loaded) {
 625                                 block_header = EXT4_XATTR_BHDR(&xattr_ref->block);
 626                                 block_header->h_refcount =
 627                                         to_le32(to_le32(block_header->h_refcount) - 1);
 628                                 if (!block_header->h_refcount) {
 629                                         ext4_xattr_try_free_block(xattr_ref);
 630                                         block_header = NULL;
 631                                 } else {
 632                                         block_entry = EXT4_XATTR_BFIRST(&xattr_ref->block);
 633                                         block_data = (char *)block_header + block_size_rem;
 634                                         block_size_rem -= sizeof(struct ext4_xattr_header);
 635                                         ext4_inode_set_file_acl(xattr_ref->inode_ref->inode,
 636                                                         &xattr_ref->fs->sb,
 637                                                         0);
 638
 639                                         xattr_ref->inode_ref->dirty = true;
 640                                         xattr_ref->block.dirty = true;
 641                                 }
 642                         }
 643                 }
 644                 RB_FOREACH_SAFE(item,
 645                                 ext4_xattr_tree,
 646                                 &xattr_ref->root,
 647                                 save_item) {
 648                         if (EXT4_XATTR_SIZE(item->data_size) +
 649                                 EXT4_XATTR_LEN(item->name_len) <=
 650                             inode_size_rem) {
 651                                 ibody_data = (char *)ibody_data -
 652                                         EXT4_XATTR_SIZE(item->data_size);
 653                                 entry->e_name_len   = to_le32(item->name_len);
 654                                 entry->e_name_index = item->name_index;
 655                                 entry->e_value_offs =
 656                                         (char *)ibody_data -
 657                                         (char *)EXT4_XATTR_IFIRST(ibody_header);
 658                                 entry->e_value_block = 0;
 659                                 entry->e_value_size = item->data_size;
 660                                 memcpy(EXT4_XATTR_NAME(entry),
 661                                         item->name, item->name_len);
 662                                 memcpy(ibody_data, item->data, item->data_size);
 663                                 entry = EXT4_XATTR_NEXT(entry);
 664                                 inode_size_rem -=
 665                                         EXT4_XATTR_SIZE(item->data_size) +
 666                                         EXT4_XATTR_LEN(item->name_len);
 667
 668                                 xattr_ref->inode_ref->dirty = true;
 669                                 continue;
 670                         }
 671                         if (EXT4_XATTR_SIZE(item->data_size) +
 672                                 EXT4_XATTR_LEN(item->name_len) > block_size_rem) {
 673                                 ret = ENOSPC;
 674                                 goto Finish;
 675                         }
 676                         block_data = (char *)block_data -
 677                                 EXT4_XATTR_SIZE(item->data_size);
 678                         block_entry->e_name_len   = to_le32(item->name_len);
 679                         block_entry->e_name_index = item->name_index;
 680                         block_entry->e_value_offs =
 681                                 (char *)block_data - (char *)block_header;
 682                         block_entry->e_value_block = 0;
 683                         block_entry->e_value_size = item->data_size;
 684                         memcpy(EXT4_XATTR_NAME(block_entry),
 685                                 item->name, item->name_len);
 686                         memcpy(block_data,
 687                                 item->data, item->data_size);
 688                         block_entry = EXT4_XATTR_NEXT(block_entry);
 689                         block_size_rem -=
 690                                 EXT4_XATTR_SIZE(item->data_size) +
 691                                 EXT4_XATTR_LEN(item->name_len);
 692
 693                         block_modified = true;
 694                 }
 695                 xattr_ref->dirty = false;
 696                 if (block_modified) {
 697                         ext4_xattr_rehash(block_header,
 698                                           EXT4_XATTR_BFIRST(&xattr_ref->block));
 699                         xattr_ref->block.dirty = true;
 700                 }
 701         }
 702
 703 Finish:
 704         return ret;
 705 }
 706
 707
 708 int ext4_fs_set_xattr(struct ext4_xattr_ref *ref,
 709                       uint8_t name_index,
 710                       char   *name,
 711                       size_t  name_len,
 712                       void   *data,
 713                       size_t  data_size,
 714                       bool    replace)
 715 {
 716         int ret = EOK;
 717         struct ext4_xattr_item *item =
 718                 ext4_xattr_lookup_item(ref,
 719                                         name_index,
 720                                         name,
 721                                         name_len);
 722         if (replace) {
 723                 if (!item) {
 724                         ret = ENOATTR;
 725                         goto Finish;
 726                 }
 727                 if (item->data_size != data_size)
 728                         ret = ext4_xattr_resize_item(ref,
 729                                                      item,
 730                                                      data_size);
 731
 732                 if (ret != EOK) {
 733                         goto Finish;
 734                 }
 735                 memcpy(item->data, data, data_size);
 736         } else {
 737                 if (item) {
 738                         ret = EEXIST;
 739                         goto Finish;
 740                 }
 741                 item = ext4_xattr_insert_item(ref,
 742                                               name_index,
 743                                               name,
 744                                               name_len,
 745                                               data,
 746                                               data_size);
 747                 if (!item)
 748                         ret = ENOMEM;
 749
 750         }
 751 Finish:
 752         return ret;
 753 }
 754
 755 int ext4_fs_remove_xattr(struct ext4_xattr_ref *ref,
 756                          uint8_t name_index,
 757                          char   *name,
 758                          size_t  name_len)
 759 {
 760         return ext4_xattr_remove_item(ref,
 761                                       name_index,
 762                                       name,
 763                                       name_len);
 764 }
 765
 766 int ext4_fs_get_xattr(struct ext4_xattr_ref *ref,
 767                           uint8_t name_index,
 768                           char    *name,
 769                           size_t   name_len,
 770                           void    *buf,
 771                           size_t   buf_size,
 772                           size_t  *size_got)
 773 {
 774         int ret = EOK;
 775         size_t item_size = 0;
 776         struct ext4_xattr_item *item =
 777                 ext4_xattr_lookup_item(ref,
 778                                         name_index,
 779                                         name,
 780                                         name_len);
 781
 782         if (!item) {
 783                 ret = ENOATTR;
 784                 goto Finish;
 785         }
 786         item_size = item->data_size;
 787         if (buf_size > item_size)
 788                 buf_size = item_size;
 789
 790         if (buf)
 791                 memcpy(buf, item->data, buf_size);
 792
 793 Finish:
 794         if (size_got)
 795                 *size_got = buf_size;
 796
 797         return ret;
 798 }
 799
 800 int ext4_fs_get_xattr_ref(struct ext4_fs *fs,
 801                           struct ext4_inode_ref *inode_ref,
 802                           struct ext4_xattr_ref *ref)
 803 {
 804         int rc;
 805         uint64_t xattr_block;
 806         xattr_block = ext4_inode_get_file_acl(inode_ref->inode,
 807                                               &fs->sb);
 808         RB_INIT(&ref->root);
 809         ref->ea_size = 0;
 810         if (xattr_block) {
 811                 rc = ext4_block_get(fs->bdev,
 812                                     &ref->block, xattr_block);
 813                 if (rc != EOK)
 814                         return EIO;
 815
 816                 ref->ea_size += sizeof(struct ext4_xattr_header);
 817                 ref->block_loaded = true;
 818         } else
 819                 ref->block_loaded = false;
 820
 821         ref->inode_ref = inode_ref;
 822         ref->fs = fs;
 823
 824         if (ext4_xattr_inode_space(ref) >
 825             sizeof(struct ext4_xattr_ibody_header))
 826                 ref->ea_size += sizeof(struct ext4_xattr_ibody_header);
 827
 828         rc = ext4_xattr_fetch(ref);
 829         if (rc != EOK) {
 830                 ext4_xattr_purge_items(ref);
 831                 if (xattr_block)
 832                         ext4_block_set(fs->bdev, &inode_ref->block);
 833
 834                 ref->block_loaded = false;
 835                 return rc;
 836         }
 837         return EOK;
 838 }
 839
 840 void ext4_fs_put_xattr_ref(struct ext4_xattr_ref *ref)
 841 {
 842         ext4_xattr_write_to_disk(ref);
 843         if (ref->block_loaded) {
 844                 ext4_block_set(ref->fs->bdev, &ref->block);
 845                 ref->block_loaded = false;
 846         }
 847         ext4_xattr_purge_items(ref);
 848         ref->inode_ref = NULL;
 849         ref->fs = NULL;
 850 }
 851
 852 /**
 853  * @}
 854  */