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                 if (item == xattr_ref->iter_from)
 454                         xattr_ref->iter_from = RB_NEXT(ext4_xattr_tree,
 455                                                        &xattr_ref->root,
 456                                                        item);
 457
 458                 RB_REMOVE(ext4_xattr_tree, &xattr_ref->root, item);
 459                 ext4_xattr_item_free(item);
 460                 xattr_ref->ea_size -= EXT4_XATTR_SIZE(item->data_size) +
 461                                         EXT4_XATTR_LEN(item->name_len);
 462                 xattr_ref->dirty = true;
 463                 ret = EOK;
 464         }
 465         return ret;
 466 }
 467
 468 static int
 469 ext4_xattr_resize_item(struct ext4_xattr_ref *xattr_ref,
 470                        struct ext4_xattr_item *item,
 471                        size_t new_data_size)
 472 {
 473         int ret = EOK;
 474         if (xattr_ref->ea_size - EXT4_XATTR_SIZE(item->data_size) +
 475                                 EXT4_XATTR_SIZE(new_data_size) >
 476                 ext4_xattr_inode_space(xattr_ref) +
 477                 ext4_xattr_block_space(xattr_ref)) {
 478
 479                 return ENOSPC;
 480         }
 481         ret = ext4_xattr_item_resize_data(item,
 482                                           new_data_size);
 483         if (ret != EOK) {
 484                 return ret;
 485         }
 486         xattr_ref->ea_size -= EXT4_XATTR_SIZE(item->data_size) +
 487                                 EXT4_XATTR_SIZE(new_data_size);
 488         xattr_ref->dirty = true;
 489         return ret;
 490 }
 491
 492 static void
 493 ext4_xattr_purge_items(struct ext4_xattr_ref *xattr_ref)
 494 {
 495         struct ext4_xattr_item *item, *save_item;
 496         uint64_t xattr_block = ext4_inode_get_file_acl(xattr_ref->inode_ref->inode,
 497                                               &xattr_ref->fs->sb);
 498         RB_FOREACH_SAFE(item,
 499                         ext4_xattr_tree,
 500                         &xattr_ref->root,
 501                         save_item) {
 502                 RB_REMOVE(ext4_xattr_tree, &xattr_ref->root, item);
 503                 ext4_xattr_item_free(item);
 504         }
 505         xattr_ref->ea_size = 0;
 506         if (xattr_block)
 507                 xattr_ref->ea_size += sizeof(struct ext4_xattr_header);
 508
 509         if (ext4_xattr_inode_space(xattr_ref) >
 510             sizeof(struct ext4_xattr_ibody_header))
 511                 xattr_ref->ea_size += sizeof(struct ext4_xattr_ibody_header);
 512 }
 513
 514
 515 static int
 516 ext4_xattr_try_alloc_block(struct ext4_xattr_ref *xattr_ref)
 517 {
 518         int ret = EOK;
 519
 520         uint64_t xattr_block = 0;
 521         xattr_block = ext4_inode_get_file_acl(xattr_ref->inode_ref->inode,
 522                                               &xattr_ref->fs->sb);
 523         if (!xattr_block) {
 524                 ret = ext4_balloc_alloc_block(xattr_ref->inode_ref,
 525                                 (uint32_t *)&xattr_block);
 526                 if (ret != EOK)
 527                         goto Finish;
 528
 529                 ret = ext4_block_get(xattr_ref->fs->bdev,
 530                                 &xattr_ref->block,
 531                                 xattr_block);
 532                 if (ret != EOK) {
 533                         ext4_balloc_free_block(xattr_ref->inode_ref,
 534                                         xattr_block);
 535                         goto Finish;
 536                 }
 537
 538                 ext4_inode_set_file_acl(xattr_ref->inode_ref->inode,
 539                                         &xattr_ref->fs->sb,
 540                                         xattr_block);
 541                 xattr_ref->inode_ref->dirty = true;
 542                 xattr_ref->block_loaded = true;
 543                 xattr_ref->ea_size += sizeof(struct ext4_xattr_header);
 544         }
 545
 546 Finish:
 547         return ret;
 548 }
 549
 550 static void
 551 ext4_xattr_try_free_block(struct ext4_xattr_ref *xattr_ref)
 552 {
 553         uint64_t xattr_block;
 554         xattr_block =
 555                 ext4_inode_get_file_acl(xattr_ref->inode_ref->inode,
 556                                 &xattr_ref->fs->sb);
 557         ext4_inode_set_file_acl(xattr_ref->inode_ref->inode,
 558                         &xattr_ref->fs->sb,
 559                         0);
 560         ext4_block_set(xattr_ref->fs->bdev,
 561                         &xattr_ref->block);
 562         ext4_balloc_free_block(xattr_ref->inode_ref,
 563                         xattr_block);
 564         xattr_ref->inode_ref->dirty = true;
 565         xattr_ref->block_loaded = false;
 566         xattr_ref->ea_size -= sizeof(struct ext4_xattr_header);
 567 }
 568
 569 static void
 570 ext4_xattr_set_block_header(struct ext4_xattr_ref *xattr_ref)
 571 {
 572         struct ext4_xattr_header *block_header = NULL;
 573         block_header = EXT4_XATTR_BHDR(&xattr_ref->block);
 574
 575         memset(block_header, 0, sizeof(struct ext4_xattr_header));
 576         block_header->h_magic = EXT4_XATTR_MAGIC;
 577         block_header->h_refcount = to_le32(1);
 578         block_header->h_blocks = to_le32(1);
 579 }
 580
 581 static void
 582 ext4_xattr_set_inode_entry(struct ext4_xattr_item *item,
 583                            struct ext4_xattr_ibody_header *ibody_header,
 584                            struct ext4_xattr_entry *entry,
 585                            void *ibody_data_ptr)
 586 {
 587         entry->e_name_len   = to_le32(item->name_len);
 588         entry->e_name_index = item->name_index;
 589         entry->e_value_offs =
 590                 (char *)ibody_data_ptr -
 591                 (char *)EXT4_XATTR_IFIRST(ibody_header);
 592         entry->e_value_block = 0;
 593         entry->e_value_size = item->data_size;
 594 }
 595
 596 static void
 597 ext4_xattr_set_block_entry(struct ext4_xattr_item *item,
 598                            struct ext4_xattr_header *block_header,
 599                            struct ext4_xattr_entry *block_entry,
 600                            void *block_data_ptr)
 601 {
 602         block_entry->e_name_len   = to_le32(item->name_len);
 603         block_entry->e_name_index = item->name_index;
 604         block_entry->e_value_offs =
 605                 (char *)block_data_ptr - (char *)block_header;
 606         block_entry->e_value_block = 0;
 607         block_entry->e_value_size = item->data_size;
 608 }
 609
 610 static int
 611 ext4_xattr_write_to_disk(struct ext4_xattr_ref *xattr_ref)
 612 {
 613         int ret = EOK;
 614         bool block_modified = false;
 615         void *ibody_data, *block_data;
 616         struct ext4_xattr_item *item, *save_item;
 617         size_t inode_size_rem, block_size_rem;
 618         struct ext4_xattr_ibody_header *ibody_header = NULL;
 619         struct ext4_xattr_header *block_header = NULL;
 620         struct ext4_xattr_entry *entry = NULL;
 621         struct ext4_xattr_entry *block_entry = NULL;
 622
 623         inode_size_rem = ext4_xattr_inode_space(xattr_ref);
 624         block_size_rem = ext4_xattr_block_space(xattr_ref);
 625         if (inode_size_rem > sizeof(struct ext4_xattr_ibody_header)) {
 626                 ibody_header = EXT4_XATTR_IHDR(xattr_ref->inode_ref->inode);
 627                 entry = EXT4_XATTR_IFIRST(ibody_header);
 628         }
 629
 630         if (xattr_ref->dirty) {
 631                 /* If there are enough spaces in the ibody EA table.*/
 632                 if (inode_size_rem > sizeof(struct ext4_xattr_ibody_header)) {
 633                         memset(ibody_header, 0, inode_size_rem);
 634                         ibody_header->h_magic = EXT4_XATTR_MAGIC;
 635                         ibody_data = (char *)ibody_header + inode_size_rem;
 636                         inode_size_rem -= sizeof(struct ext4_xattr_ibody_header);
 637
 638                         xattr_ref->inode_ref->dirty = true;
 639                 }
 640                 /* If we need an extra block to hold the EA entries*/
 641                 if (xattr_ref->ea_size > inode_size_rem) {
 642                         if (!xattr_ref->block_loaded) {
 643                                 ret = ext4_xattr_try_alloc_block(xattr_ref);
 644                                 if (ret != EOK)
 645                                         goto Finish;
 646
 647                         }
 648                         block_header = EXT4_XATTR_BHDR(&xattr_ref->block);
 649                         block_entry = EXT4_XATTR_BFIRST(&xattr_ref->block);
 650                         ext4_xattr_set_block_header(xattr_ref);
 651                         block_data = (char *)block_header + block_size_rem;
 652                         block_size_rem -= sizeof(struct ext4_xattr_header);
 653
 654                         xattr_ref->block.dirty = true;
 655                 } else {
 656                         /* We don't need an extra block.*/
 657                         if (xattr_ref->block_loaded) {
 658                                 block_header = EXT4_XATTR_BHDR(&xattr_ref->block);
 659                                 block_header->h_refcount =
 660                                         to_le32(to_le32(block_header->h_refcount) - 1);
 661                                 if (!block_header->h_refcount) {
 662                                         ext4_xattr_try_free_block(xattr_ref);
 663                                         block_header = NULL;
 664                                 } else {
 665                                         block_entry = EXT4_XATTR_BFIRST(&xattr_ref->block);
 666                                         block_data = (char *)block_header + block_size_rem;
 667                                         block_size_rem -= sizeof(struct ext4_xattr_header);
 668                                         ext4_inode_set_file_acl(xattr_ref->inode_ref->inode,
 669                                                         &xattr_ref->fs->sb,
 670                                                         0);
 671
 672                                         xattr_ref->inode_ref->dirty = true;
 673                                         xattr_ref->block.dirty = true;
 674                                 }
 675                         }
 676                 }
 677                 RB_FOREACH_SAFE(item,
 678                                 ext4_xattr_tree,
 679                                 &xattr_ref->root,
 680                                 save_item) {
 681                         if (EXT4_XATTR_SIZE(item->data_size) +
 682                                 EXT4_XATTR_LEN(item->name_len) <=
 683                             inode_size_rem) {
 684                                 ibody_data = (char *)ibody_data -
 685                                         EXT4_XATTR_SIZE(item->data_size);
 686                                 ext4_xattr_set_inode_entry(item,
 687                                                            ibody_header,
 688                                                            entry,
 689                                                            ibody_data);
 690                                 memcpy(EXT4_XATTR_NAME(entry),
 691                                         item->name, item->name_len);
 692                                 memcpy(ibody_data, item->data, item->data_size);
 693                                 entry = EXT4_XATTR_NEXT(entry);
 694                                 inode_size_rem -=
 695                                         EXT4_XATTR_SIZE(item->data_size) +
 696                                         EXT4_XATTR_LEN(item->name_len);
 697
 698                                 xattr_ref->inode_ref->dirty = true;
 699                                 continue;
 700                         }
 701                         if (EXT4_XATTR_SIZE(item->data_size) +
 702                                 EXT4_XATTR_LEN(item->name_len) > block_size_rem) {
 703                                 ret = ENOSPC;
 704                                 goto Finish;
 705                         }
 706                         block_data = (char *)block_data -
 707                                 EXT4_XATTR_SIZE(item->data_size);
 708                         ext4_xattr_set_block_entry(item,
 709                                                    block_header,
 710                                                    block_entry,
 711                                                    block_data);
 712                         memcpy(EXT4_XATTR_NAME(block_entry),
 713                                 item->name, item->name_len);
 714                         memcpy(block_data,
 715                                 item->data, item->data_size);
 716                         block_entry = EXT4_XATTR_NEXT(block_entry);
 717                         block_size_rem -=
 718                                 EXT4_XATTR_SIZE(item->data_size) +
 719                                 EXT4_XATTR_LEN(item->name_len);
 720
 721                         block_modified = true;
 722                 }
 723                 xattr_ref->dirty = false;
 724                 if (block_modified) {
 725                         ext4_xattr_rehash(block_header,
 726                                           EXT4_XATTR_BFIRST(&xattr_ref->block));
 727                         xattr_ref->block.dirty = true;
 728                 }
 729         }
 730
 731 Finish:
 732         return ret;
 733 }
 734
 735 void
 736 ext4_fs_xattr_iterate(struct ext4_xattr_ref *ref,
 737                       int (iter)(struct ext4_xattr_ref *ref,
 738                                  struct ext4_xattr_item *item))
 739 {
 740         struct ext4_xattr_item *item;
 741         if (!ref->iter_from)
 742                 ref->iter_from = RB_MIN(ext4_xattr_tree, &ref->root);
 743
 744         RB_FOREACH_FROM(item,
 745                         ext4_xattr_tree,
 746                         ref->iter_from) {
 747                 int ret = EXT4_XATTR_ITERATE_CONT;
 748                 if (iter)
 749                         iter(ref, item);
 750
 751                 if (ret != EXT4_XATTR_ITERATE_CONT) {
 752                         if (ret == EXT4_XATTR_ITERATE_STOP)
 753                                 ref->iter_from = NULL;
 754
 755                         break;
 756                 }
 757         }
 758 }
 759
 760 static void
 761 ext4_fs_xattr_iterate_reset(struct ext4_xattr_ref *ref)
 762 {
 763         ref->iter_from = NULL;
 764 }
 765
 766 int ext4_fs_set_xattr(struct ext4_xattr_ref *ref,
 767                       uint8_t name_index,
 768                       char   *name,
 769                       size_t  name_len,
 770                       void   *data,
 771                       size_t  data_size,
 772                       bool    replace)
 773 {
 774         int ret = EOK;
 775         struct ext4_xattr_item *item =
 776                 ext4_xattr_lookup_item(ref,
 777                                         name_index,
 778                                         name,
 779                                         name_len);
 780         if (replace) {
 781                 if (!item) {
 782                         ret = ENOATTR;
 783                         goto Finish;
 784                 }
 785                 if (item->data_size != data_size)
 786                         ret = ext4_xattr_resize_item(ref,
 787                                                      item,
 788                                                      data_size);
 789
 790                 if (ret != EOK) {
 791                         goto Finish;
 792                 }
 793                 memcpy(item->data, data, data_size);
 794         } else {
 795                 if (item) {
 796                         ret = EEXIST;
 797                         goto Finish;
 798                 }
 799                 item = ext4_xattr_insert_item(ref,
 800                                               name_index,
 801                                               name,
 802                                               name_len,
 803                                               data,
 804                                               data_size);
 805                 if (!item)
 806                         ret = ENOMEM;
 807
 808         }
 809 Finish:
 810         return ret;
 811 }
 812
 813 int ext4_fs_remove_xattr(struct ext4_xattr_ref *ref,
 814                          uint8_t name_index,
 815                          char   *name,
 816                          size_t  name_len)
 817 {
 818         return ext4_xattr_remove_item(ref,
 819                                       name_index,
 820                                       name,
 821                                       name_len);
 822 }
 823
 824 int ext4_fs_get_xattr(struct ext4_xattr_ref *ref,
 825                           uint8_t name_index,
 826                           char    *name,
 827                           size_t   name_len,
 828                           void    *buf,
 829                           size_t   buf_size,
 830                           size_t  *size_got)
 831 {
 832         int ret = EOK;
 833         size_t item_size = 0;
 834         struct ext4_xattr_item *item =
 835                 ext4_xattr_lookup_item(ref,
 836                                         name_index,
 837                                         name,
 838                                         name_len);
 839
 840         if (!item) {
 841                 ret = ENOATTR;
 842                 goto Finish;
 843         }
 844         item_size = item->data_size;
 845         if (buf_size > item_size)
 846                 buf_size = item_size;
 847
 848         if (buf)
 849                 memcpy(buf, item->data, buf_size);
 850
 851 Finish:
 852         if (size_got)
 853                 *size_got = buf_size;
 854
 855         return ret;
 856 }
 857
 858 int ext4_fs_get_xattr_ref(struct ext4_fs *fs,
 859                           struct ext4_inode_ref *inode_ref,
 860                           struct ext4_xattr_ref *ref)
 861 {
 862         int rc;
 863         uint64_t xattr_block;
 864         xattr_block = ext4_inode_get_file_acl(inode_ref->inode,
 865                                               &fs->sb);
 866         RB_INIT(&ref->root);
 867         ref->ea_size = 0;
 868         ref->iter_from = NULL;
 869         if (xattr_block) {
 870                 rc = ext4_block_get(fs->bdev,
 871                                     &ref->block, xattr_block);
 872                 if (rc != EOK)
 873                         return EIO;
 874
 875                 ref->ea_size += sizeof(struct ext4_xattr_header);
 876                 ref->block_loaded = true;
 877         } else
 878                 ref->block_loaded = false;
 879
 880         ref->inode_ref = inode_ref;
 881         ref->fs = fs;
 882
 883         if (ext4_xattr_inode_space(ref) >
 884             sizeof(struct ext4_xattr_ibody_header))
 885                 ref->ea_size += sizeof(struct ext4_xattr_ibody_header);
 886
 887         rc = ext4_xattr_fetch(ref);
 888         if (rc != EOK) {
 889                 ext4_xattr_purge_items(ref);
 890                 if (xattr_block)
 891                         ext4_block_set(fs->bdev, &inode_ref->block);
 892
 893                 ref->block_loaded = false;
 894                 return rc;
 895         }
 896         return EOK;
 897 }
 898
 899 void ext4_fs_put_xattr_ref(struct ext4_xattr_ref *ref)
 900 {
 901         ext4_xattr_write_to_disk(ref);
 902         if (ref->block_loaded) {
 903                 ext4_block_set(ref->fs->bdev, &ref->block);
 904                 ref->block_loaded = false;
 905         }
 906         ext4_xattr_purge_items(ref);
 907         ref->inode_ref = NULL;
 908         ref->fs = NULL;
 909 }
 910
 911 /**
 912  * @}
 913  */