lib/ext2fs/ext_attr.c

   1 /*
   2  * ext_attr.c --- extended attribute blocks
   3  *
   4  * Copyright (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
   5  *
   6  * Copyright (C) 2002 Theodore Ts'o.
   7  *
   8  * %Begin-Header%
   9  * This file may be redistributed under the terms of the GNU Library
  10  * General Public License, version 2.
  11  * %End-Header%
  12  */
  13
  14 #include "config.h"
  15 #include <stdio.h>
  16 #if HAVE_UNISTD_H
  17 #include <unistd.h>
  18 #endif
  19 #include <string.h>
  20 #include <time.h>
  21
  22 #include "ext2_fs.h"
  23 #include "ext2_ext_attr.h"
  24 #include "ext4_acl.h"
  25
  26 #include "ext2fs.h"
  27
  28 static errcode_t read_ea_inode_hash(ext2_filsys fs, ext2_ino_t ino, __u32 *hash)
  29 {
  30         struct ext2_inode inode;
  31         errcode_t retval;
  32
  33         retval = ext2fs_read_inode(fs, ino, &inode);
  34         if (retval)
  35                 return retval;
  36         *hash = ext2fs_get_ea_inode_hash(&inode);
  37         return 0;
  38 }
  39
  40 #define NAME_HASH_SHIFT 5
  41 #define VALUE_HASH_SHIFT 16
  42
  43 /*
  44  * ext2_xattr_hash_entry()
  45  *
  46  * Compute the hash of an extended attribute.
  47  */
  48 __u32 ext2fs_ext_attr_hash_entry(struct ext2_ext_attr_entry *entry, void *data)
  49 {
  50         __u32 hash = 0;
  51         char *name = ((char *) entry) + sizeof(struct ext2_ext_attr_entry);
  52         int n;
  53
  54         for (n = 0; n < entry->e_name_len; n++) {
  55                 hash = (hash << NAME_HASH_SHIFT) ^
  56                        (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
  57                        *name++;
  58         }
  59
  60         /* The hash needs to be calculated on the data in little-endian. */
  61         if (entry->e_value_inum == 0 && entry->e_value_size != 0) {
  62                 __u32 *value = (__u32 *)data;
  63                 for (n = (entry->e_value_size + EXT2_EXT_ATTR_ROUND) >>
  64                          EXT2_EXT_ATTR_PAD_BITS; n; n--) {
  65                         hash = (hash << VALUE_HASH_SHIFT) ^
  66                                (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
  67                                ext2fs_le32_to_cpu(*value++);
  68                 }
  69         }
  70
  71         return hash;
  72 }
  73
  74 /*
  75  * ext2fs_ext_attr_hash_entry2()
  76  *
  77  * Compute the hash of an extended attribute.
  78  * This version of the function supports hashing entries that reference
  79  * external inodes (ea_inode feature).
  80  */
  81 errcode_t ext2fs_ext_attr_hash_entry2(ext2_filsys fs,
  82                                       struct ext2_ext_attr_entry *entry,
  83                                       void *data, __u32 *hash)
  84 {
  85         *hash = ext2fs_ext_attr_hash_entry(entry, data);
  86
  87         if (entry->e_value_inum) {
  88                 __u32 ea_inode_hash;
  89                 errcode_t retval;
  90
  91                 retval = read_ea_inode_hash(fs, entry->e_value_inum,
  92                                             &ea_inode_hash);
  93                 if (retval)
  94                         return retval;
  95
  96                 *hash = (*hash << VALUE_HASH_SHIFT) ^
  97                         (*hash >> (8*sizeof(*hash) - VALUE_HASH_SHIFT)) ^
  98                         ea_inode_hash;
  99         }
 100         return 0;
 101 }
 102
 103 #undef NAME_HASH_SHIFT
 104 #undef VALUE_HASH_SHIFT
 105
 106 #define BLOCK_HASH_SHIFT 16
 107
 108 /* Mirrors ext4_xattr_rehash() implementation in kernel. */
 109 void ext2fs_ext_attr_block_rehash(struct ext2_ext_attr_header *header,
 110                                   struct ext2_ext_attr_entry *end)
 111 {
 112         struct ext2_ext_attr_entry *here;
 113         __u32 hash = 0;
 114
 115         here = (struct ext2_ext_attr_entry *)(header+1);
 116         while (here < end && !EXT2_EXT_IS_LAST_ENTRY(here)) {
 117                 if (!here->e_hash) {
 118                         /* Block is not shared if an entry's hash value == 0 */
 119                         hash = 0;
 120                         break;
 121                 }
 122                 hash = (hash << BLOCK_HASH_SHIFT) ^
 123                        (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
 124                        here->e_hash;
 125                 here = EXT2_EXT_ATTR_NEXT(here);
 126         }
 127         header->h_hash = hash;
 128 }
 129
 130 #undef BLOCK_HASH_SHIFT
 131
 132 __u32 ext2fs_get_ea_inode_hash(struct ext2_inode *inode)
 133 {
 134         return inode->i_atime;
 135 }
 136
 137 void ext2fs_set_ea_inode_hash(struct ext2_inode *inode, __u32 hash)
 138 {
 139         inode->i_atime = hash;
 140 }
 141
 142 __u64 ext2fs_get_ea_inode_ref(struct ext2_inode *inode)
 143 {
 144         return ((__u64)inode->i_ctime << 32) | inode->osd1.linux1.l_i_version;
 145 }
 146
 147 void ext2fs_set_ea_inode_ref(struct ext2_inode *inode, __u64 ref_count)
 148 {
 149         inode->i_ctime = (__u32)(ref_count >> 32);
 150         inode->osd1.linux1.l_i_version = (__u32)ref_count;
 151 }
 152
 153 static errcode_t check_ext_attr_header(struct ext2_ext_attr_header *header)
 154 {
 155         if ((header->h_magic != EXT2_EXT_ATTR_MAGIC_v1 &&
 156              header->h_magic != EXT2_EXT_ATTR_MAGIC) ||
 157             header->h_blocks != 1)
 158                 return EXT2_ET_BAD_EA_HEADER;
 159
 160         return 0;
 161 }
 162
 163 errcode_t ext2fs_read_ext_attr3(ext2_filsys fs, blk64_t block, void *buf,
 164                                 ext2_ino_t inum)
 165 {
 166         int             csum_failed = 0;
 167         errcode_t       retval;
 168
 169         retval = io_channel_read_blk64(fs->io, block, 1, buf);
 170         if (retval)
 171                 return retval;
 172
 173         if (!(fs->flags & EXT2_FLAG_IGNORE_CSUM_ERRORS) &&
 174             !ext2fs_ext_attr_block_csum_verify(fs, inum, block, buf))
 175                 csum_failed = 1;
 176
 177 #ifdef WORDS_BIGENDIAN
 178         ext2fs_swap_ext_attr(buf, buf, fs->blocksize, 1);
 179 #endif
 180
 181         retval = check_ext_attr_header(buf);
 182         if (retval == 0 && csum_failed)
 183                 retval = EXT2_ET_EXT_ATTR_CSUM_INVALID;
 184
 185         return retval;
 186 }
 187
 188 errcode_t ext2fs_read_ext_attr2(ext2_filsys fs, blk64_t block, void *buf)
 189 {
 190         return ext2fs_read_ext_attr3(fs, block, buf, 0);
 191 }
 192
 193 errcode_t ext2fs_read_ext_attr(ext2_filsys fs, blk_t block, void *buf)
 194 {
 195         return ext2fs_read_ext_attr2(fs, block, buf);
 196 }
 197
 198 errcode_t ext2fs_write_ext_attr3(ext2_filsys fs, blk64_t block, void *inbuf,
 199                                  ext2_ino_t inum)
 200 {
 201         errcode_t       retval;
 202         char            *write_buf;
 203
 204 #ifdef WORDS_BIGENDIAN
 205         retval = ext2fs_get_mem(fs->blocksize, &write_buf);
 206         if (retval)
 207                 return retval;
 208         ext2fs_swap_ext_attr(write_buf, inbuf, fs->blocksize, 1);
 209 #else
 210         write_buf = (char *) inbuf;
 211 #endif
 212
 213         retval = ext2fs_ext_attr_block_csum_set(fs, inum, block,
 214                         (struct ext2_ext_attr_header *)write_buf);
 215         if (retval)
 216                 return retval;
 217
 218         retval = io_channel_write_blk64(fs->io, block, 1, write_buf);
 219 #ifdef WORDS_BIGENDIAN
 220         ext2fs_free_mem(&write_buf);
 221 #endif
 222         if (!retval)
 223                 ext2fs_mark_changed(fs);
 224         return retval;
 225 }
 226
 227 errcode_t ext2fs_write_ext_attr2(ext2_filsys fs, blk64_t block, void *inbuf)
 228 {
 229         return ext2fs_write_ext_attr3(fs, block, inbuf, 0);
 230 }
 231
 232 errcode_t ext2fs_write_ext_attr(ext2_filsys fs, blk_t block, void *inbuf)
 233 {
 234         return ext2fs_write_ext_attr2(fs, block, inbuf);
 235 }
 236
 237 /*
 238  * This function adjusts the reference count of the EA block.
 239  */
 240 errcode_t ext2fs_adjust_ea_refcount3(ext2_filsys fs, blk64_t blk,
 241                                     char *block_buf, int adjust,
 242                                     __u32 *newcount, ext2_ino_t inum)
 243 {
 244         errcode_t       retval;
 245         struct ext2_ext_attr_header *header;
 246         char    *buf = 0;
 247
 248         if ((blk >= ext2fs_blocks_count(fs->super)) ||
 249             (blk < fs->super->s_first_data_block))
 250                 return EXT2_ET_BAD_EA_BLOCK_NUM;
 251
 252         if (!block_buf) {
 253                 retval = ext2fs_get_mem(fs->blocksize, &buf);
 254                 if (retval)
 255                         return retval;
 256                 block_buf = buf;
 257         }
 258
 259         retval = ext2fs_read_ext_attr3(fs, blk, block_buf, inum);
 260         if (retval)
 261                 goto errout;
 262
 263         header = (struct ext2_ext_attr_header *) block_buf;
 264         header->h_refcount += adjust;
 265         if (newcount)
 266                 *newcount = header->h_refcount;
 267
 268         retval = ext2fs_write_ext_attr3(fs, blk, block_buf, inum);
 269         if (retval)
 270                 goto errout;
 271
 272 errout:
 273         if (buf)
 274                 ext2fs_free_mem(&buf);
 275         return retval;
 276 }
 277
 278 errcode_t ext2fs_adjust_ea_refcount2(ext2_filsys fs, blk64_t blk,
 279                                     char *block_buf, int adjust,
 280                                     __u32 *newcount)
 281 {
 282         return ext2fs_adjust_ea_refcount3(fs, blk, block_buf, adjust,
 283                                           newcount, 0);
 284 }
 285
 286 errcode_t ext2fs_adjust_ea_refcount(ext2_filsys fs, blk_t blk,
 287                                         char *block_buf, int adjust,
 288                                         __u32 *newcount)
 289 {
 290         return ext2fs_adjust_ea_refcount2(fs, blk, block_buf, adjust,
 291                                           newcount);
 292 }
 293
 294 /* Manipulate the contents of extended attribute regions */
 295 struct ext2_xattr {
 296         char *name;
 297         void *value;
 298         unsigned int value_len;
 299         ext2_ino_t ea_ino;
 300 };
 301
 302 struct ext2_xattr_handle {
 303         errcode_t magic;
 304         ext2_filsys fs;
 305         struct ext2_xattr *attrs;
 306         int capacity;
 307         int count;
 308         int ibody_count;
 309         ext2_ino_t ino;
 310         unsigned int flags;
 311 };
 312
 313 static errcode_t ext2fs_xattrs_expand(struct ext2_xattr_handle *h,
 314                                       unsigned int expandby)
 315 {
 316         struct ext2_xattr *new_attrs;
 317         errcode_t err;
 318
 319         err = ext2fs_get_arrayzero(h->capacity + expandby,
 320                                    sizeof(struct ext2_xattr), &new_attrs);
 321         if (err)
 322                 return err;
 323
 324         memcpy(new_attrs, h->attrs, h->capacity * sizeof(struct ext2_xattr));
 325         ext2fs_free_mem(&h->attrs);
 326         h->capacity += expandby;
 327         h->attrs = new_attrs;
 328
 329         return 0;
 330 }
 331
 332 struct ea_name_index {
 333         int index;
 334         const char *name;
 335 };
 336
 337 /* Keep these names sorted in order of decreasing specificity. */
 338 static struct ea_name_index ea_names[] = {
 339         {3, "system.posix_acl_default"},
 340         {2, "system.posix_acl_access"},
 341         {8, "system.richacl"},
 342         {6, "security."},
 343         {4, "trusted."},
 344         {7, "system."},
 345         {1, "user."},
 346         {0, NULL},
 347 };
 348
 349 static const char *find_ea_prefix(int index)
 350 {
 351         struct ea_name_index *e;
 352
 353         for (e = ea_names; e->name; e++)
 354                 if (e->index == index)
 355                         return e->name;
 356
 357         return NULL;
 358 }
 359
 360 static int find_ea_index(const char *fullname, const char **name, int *index)
 361 {
 362         struct ea_name_index *e;
 363
 364         for (e = ea_names; e->name; e++) {
 365                 if (strncmp(fullname, e->name, strlen(e->name)) == 0) {
 366                         *name = fullname + strlen(e->name);
 367                         *index = e->index;
 368                         return 1;
 369                 }
 370         }
 371         return 0;
 372 }
 373
 374 errcode_t ext2fs_free_ext_attr(ext2_filsys fs, ext2_ino_t ino,
 375                                struct ext2_inode_large *inode)
 376 {
 377         struct ext2_ext_attr_header *header;
 378         void *block_buf = NULL;
 379         blk64_t blk;
 380         errcode_t err;
 381         struct ext2_inode_large i;
 382
 383         /* Read inode? */
 384         if (inode == NULL) {
 385                 err = ext2fs_read_inode_full(fs, ino, (struct ext2_inode *)&i,
 386                                              sizeof(struct ext2_inode_large));
 387                 if (err)
 388                         return err;
 389                 inode = &i;
 390         }
 391
 392         /* Do we already have an EA block? */
 393         blk = ext2fs_file_acl_block(fs, (struct ext2_inode *)inode);
 394         if (blk == 0)
 395                 return 0;
 396
 397         /* Find block, zero it, write back */
 398         if ((blk < fs->super->s_first_data_block) ||
 399             (blk >= ext2fs_blocks_count(fs->super))) {
 400                 err = EXT2_ET_BAD_EA_BLOCK_NUM;
 401                 goto out;
 402         }
 403
 404         err = ext2fs_get_mem(fs->blocksize, &block_buf);
 405         if (err)
 406                 goto out;
 407
 408         err = ext2fs_read_ext_attr3(fs, blk, block_buf, ino);
 409         if (err)
 410                 goto out2;
 411
 412         /* We only know how to deal with v2 EA blocks */
 413         header = (struct ext2_ext_attr_header *) block_buf;
 414         if (header->h_magic != EXT2_EXT_ATTR_MAGIC) {
 415                 err = EXT2_ET_BAD_EA_HEADER;
 416                 goto out2;
 417         }
 418
 419         header->h_refcount--;
 420         err = ext2fs_write_ext_attr3(fs, blk, block_buf, ino);
 421         if (err)
 422                 goto out2;
 423
 424         /* Erase link to block */
 425         ext2fs_file_acl_block_set(fs, (struct ext2_inode *)inode, 0);
 426         if (header->h_refcount == 0)
 427                 ext2fs_block_alloc_stats2(fs, blk, -1);
 428         err = ext2fs_iblk_sub_blocks(fs, (struct ext2_inode *)inode, 1);
 429         if (err)
 430                 goto out2;
 431
 432         /* Write inode? */
 433         if (inode == &i) {
 434                 err = ext2fs_write_inode_full(fs, ino, (struct ext2_inode *)&i,
 435                                               sizeof(struct ext2_inode_large));
 436                 if (err)
 437                         goto out2;
 438         }
 439
 440 out2:
 441         ext2fs_free_mem(&block_buf);
 442 out:
 443         return err;
 444 }
 445
 446 static errcode_t prep_ea_block_for_write(ext2_filsys fs, ext2_ino_t ino,
 447                                          struct ext2_inode_large *inode)
 448 {
 449         struct ext2_ext_attr_header *header;
 450         void *block_buf = NULL;
 451         blk64_t blk, goal;
 452         errcode_t err;
 453
 454         /* Do we already have an EA block? */
 455         blk = ext2fs_file_acl_block(fs, (struct ext2_inode *)inode);
 456         if (blk != 0) {
 457                 if ((blk < fs->super->s_first_data_block) ||
 458                     (blk >= ext2fs_blocks_count(fs->super))) {
 459                         err = EXT2_ET_BAD_EA_BLOCK_NUM;
 460                         goto out;
 461                 }
 462
 463                 err = ext2fs_get_mem(fs->blocksize, &block_buf);
 464                 if (err)
 465                         goto out;
 466
 467                 err = ext2fs_read_ext_attr3(fs, blk, block_buf, ino);
 468                 if (err)
 469                         goto out2;
 470
 471                 /* We only know how to deal with v2 EA blocks */
 472                 header = (struct ext2_ext_attr_header *) block_buf;
 473                 if (header->h_magic != EXT2_EXT_ATTR_MAGIC) {
 474                         err = EXT2_ET_BAD_EA_HEADER;
 475                         goto out2;
 476                 }
 477
 478                 /* Single-user block.  We're done here. */
 479                 if (header->h_refcount == 1)
 480                         goto out2;
 481
 482                 /* We need to CoW the block. */
 483                 header->h_refcount--;
 484                 err = ext2fs_write_ext_attr3(fs, blk, block_buf, ino);
 485                 if (err)
 486                         goto out2;
 487         } else {
 488                 /* No block, we must increment i_blocks */
 489                 err = ext2fs_iblk_add_blocks(fs, (struct ext2_inode *)inode,
 490                                              1);
 491                 if (err)
 492                         goto out;
 493         }
 494
 495         /* Allocate a block */
 496         goal = ext2fs_find_inode_goal(fs, ino, (struct ext2_inode *)inode, 0);
 497         err = ext2fs_alloc_block2(fs, goal, NULL, &blk);
 498         if (err)
 499                 goto out2;
 500         ext2fs_file_acl_block_set(fs, (struct ext2_inode *)inode, blk);
 501 out2:
 502         if (block_buf)
 503                 ext2fs_free_mem(&block_buf);
 504 out:
 505         return err;
 506 }
 507
 508
 509 static inline int
 510 posix_acl_xattr_count(size_t size)
 511 {
 512         if (size < sizeof(posix_acl_xattr_header))
 513                 return -1;
 514         size -= sizeof(posix_acl_xattr_header);
 515         if (size % sizeof(posix_acl_xattr_entry))
 516                 return -1;
 517         return size / sizeof(posix_acl_xattr_entry);
 518 }
 519
 520 /*
 521  * The lgetxattr function returns data formatted in the POSIX extended
 522  * attribute format.  The on-disk format uses a more compact encoding.
 523  * See the ext4_acl_to_disk in fs/ext4/acl.c.
 524  */
 525 static errcode_t convert_posix_acl_to_disk_buffer(const void *value, size_t size,
 526                                                   void *out_buf, size_t *size_out)
 527 {
 528         const posix_acl_xattr_header *header =
 529                 (const posix_acl_xattr_header*) value;
 530         const posix_acl_xattr_entry *end, *entry =
 531                 (const posix_acl_xattr_entry *)(header+1);
 532         ext4_acl_header *ext_acl;
 533         size_t s;
 534         char *e;
 535
 536         int count;
 537
 538         if (!value)
 539                 return EINVAL;
 540         if (size < sizeof(posix_acl_xattr_header))
 541                 return ENOMEM;
 542         if (header->a_version != ext2fs_cpu_to_le32(POSIX_ACL_XATTR_VERSION))
 543                 return EINVAL;
 544
 545         count = posix_acl_xattr_count(size);
 546         ext_acl = out_buf;
 547         ext_acl->a_version = ext2fs_cpu_to_le32(EXT4_ACL_VERSION);
 548
 549         if (count <= 0)
 550                 return EINVAL;
 551
 552         e = (char *) out_buf + sizeof(ext4_acl_header);
 553         s = sizeof(ext4_acl_header);
 554         for (end = entry + count; entry != end;entry++) {
 555                 ext4_acl_entry *disk_entry = (ext4_acl_entry*) e;
 556                 disk_entry->e_tag = ext2fs_cpu_to_le16(entry->e_tag);
 557                 disk_entry->e_perm = ext2fs_cpu_to_le16(entry->e_perm);
 558
 559                 switch(entry->e_tag) {
 560                         case ACL_USER_OBJ:
 561                         case ACL_GROUP_OBJ:
 562                         case ACL_MASK:
 563                         case ACL_OTHER:
 564                                 e += sizeof(ext4_acl_entry_short);
 565                                 s += sizeof(ext4_acl_entry_short);
 566                                 break;
 567                         case ACL_USER:
 568                         case ACL_GROUP:
 569                                 disk_entry->e_id =  ext2fs_cpu_to_le32(entry->e_id);
 570                                 e += sizeof(ext4_acl_entry);
 571                                 s += sizeof(ext4_acl_entry);
 572                                 break;
 573                 }
 574         }
 575         *size_out = s;
 576         return 0;
 577 }
 578
 579 static errcode_t convert_disk_buffer_to_posix_acl(const void *value, size_t size,
 580                                                   void **out_buf, size_t *size_out)
 581 {
 582         posix_acl_xattr_header *header;
 583         posix_acl_xattr_entry *entry;
 584         const ext4_acl_header *ext_acl = (const ext4_acl_header *) value;
 585         errcode_t err;
 586         const char *cp;
 587         char *out;
 588
 589         if ((!value) ||
 590             (size < sizeof(ext4_acl_header)) ||
 591             (ext_acl->a_version != ext2fs_cpu_to_le32(EXT4_ACL_VERSION)))
 592                 return EINVAL;
 593
 594         err = ext2fs_get_mem(size * 2, &out);
 595         if (err)
 596                 return err;
 597
 598         header = (posix_acl_xattr_header *) out;
 599         header->a_version = ext2fs_cpu_to_le32(POSIX_ACL_XATTR_VERSION);
 600         entry = (posix_acl_xattr_entry *) (out + sizeof(posix_acl_xattr_header));
 601
 602         cp = (const char *) value + sizeof(ext4_acl_header);
 603         size -= sizeof(ext4_acl_header);
 604
 605         while (size > 0) {
 606                 const ext4_acl_entry *disk_entry = (const ext4_acl_entry *) cp;
 607
 608                 entry->e_tag = ext2fs_le16_to_cpu(disk_entry->e_tag);
 609                 entry->e_perm = ext2fs_le16_to_cpu(disk_entry->e_perm);
 610
 611                 switch(entry->e_tag) {
 612                         case ACL_USER_OBJ:
 613                         case ACL_GROUP_OBJ:
 614                         case ACL_MASK:
 615                         case ACL_OTHER:
 616                                 entry->e_id = 0;
 617                                 cp += sizeof(ext4_acl_entry_short);
 618                                 size -= sizeof(ext4_acl_entry_short);
 619                                 break;
 620                         case ACL_USER:
 621                         case ACL_GROUP:
 622                                 entry->e_id = ext2fs_le32_to_cpu(disk_entry->e_id);
 623                                 cp += sizeof(ext4_acl_entry);
 624                                 size -= sizeof(ext4_acl_entry);
 625                                 break;
 626                 default:
 627                         ext2fs_free_mem(&out);
 628                         return EINVAL;
 629                         break;
 630                 }
 631                 entry++;
 632         }
 633         *out_buf = out;
 634         *size_out = ((char *) entry - out);
 635         return 0;
 636 }
 637
 638 static errcode_t
 639 write_xattrs_to_buffer(ext2_filsys fs, struct ext2_xattr *attrs, int count,
 640                        void *entries_start, unsigned int storage_size,
 641                        unsigned int value_offset_correction, int write_hash)
 642 {
 643         struct ext2_xattr *x;
 644         struct ext2_ext_attr_entry *e = entries_start;
 645         char *end = (char *) entries_start + storage_size;
 646         const char *shortname;
 647         unsigned int value_size;
 648         int idx, ret;
 649         errcode_t err;
 650
 651         memset(entries_start, 0, storage_size);
 652         for (x = attrs; x < attrs + count; x++) {
 653                 /* Calculate index and shortname position */
 654                 shortname = x->name;
 655                 ret = find_ea_index(x->name, &shortname, &idx);
 656
 657                 value_size = ((x->value_len + EXT2_EXT_ATTR_PAD - 1) /
 658                               EXT2_EXT_ATTR_PAD) * EXT2_EXT_ATTR_PAD;
 659
 660                 /* Fill out e appropriately */
 661                 e->e_name_len = strlen(shortname);
 662                 e->e_name_index = (ret ? idx : 0);
 663
 664                 e->e_value_size = x->value_len;
 665                 e->e_value_inum = x->ea_ino;
 666
 667                 /* Store name */
 668                 memcpy((char *)e + sizeof(*e), shortname, e->e_name_len);
 669                 if (x->ea_ino) {
 670                         e->e_value_offs = 0;
 671                 } else {
 672                         end -= value_size;
 673                         e->e_value_offs = end - (char *) entries_start +
 674                                                 value_offset_correction;
 675                         memcpy(end, x->value, e->e_value_size);
 676                 }
 677
 678                 if (write_hash || x->ea_ino) {
 679                         err = ext2fs_ext_attr_hash_entry2(fs, e,
 680                                                           x->ea_ino ? 0 : end,
 681                                                           &e->e_hash);
 682                         if (err)
 683                                 return err;
 684                 } else
 685                         e->e_hash = 0;
 686
 687                 e = EXT2_EXT_ATTR_NEXT(e);
 688                 *(__u32 *)e = 0;
 689         }
 690         return 0;
 691 }
 692
 693 errcode_t ext2fs_xattrs_write(struct ext2_xattr_handle *handle)
 694 {
 695         ext2_filsys fs = handle->fs;
 696         const unsigned int inode_size = EXT2_INODE_SIZE(fs->super);
 697         struct ext2_inode_large *inode;
 698         char *start, *block_buf = NULL;
 699         struct ext2_ext_attr_header *header;
 700         __u32 ea_inode_magic;
 701         blk64_t blk;
 702         unsigned int storage_size;
 703         unsigned int i;
 704         errcode_t err;
 705
 706         EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EA_HANDLE);
 707         i = inode_size;
 708         if (i < sizeof(*inode))
 709                 i = sizeof(*inode);
 710         err = ext2fs_get_memzero(i, &inode);
 711         if (err)
 712                 return err;
 713
 714         err = ext2fs_read_inode_full(fs, handle->ino, EXT2_INODE(inode),
 715                                      inode_size);
 716         if (err)
 717                 goto out;
 718
 719         /* If extra_isize isn't set, we need to set it now */
 720         if (inode->i_extra_isize == 0 &&
 721             inode_size > EXT2_GOOD_OLD_INODE_SIZE) {
 722                 char *p = (char *)inode;
 723                 size_t extra = fs->super->s_want_extra_isize;
 724
 725                 if (extra == 0)
 726                         extra = sizeof(__u32);
 727                 memset(p + EXT2_GOOD_OLD_INODE_SIZE, 0, extra);
 728                 inode->i_extra_isize = extra;
 729         }
 730         if (inode->i_extra_isize & 3) {
 731                 err = EXT2_ET_INODE_CORRUPTED;
 732                 goto out;
 733         }
 734
 735         /* Does the inode have space for EA? */
 736         if (inode->i_extra_isize < sizeof(inode->i_extra_isize) ||
 737             inode_size <= EXT2_GOOD_OLD_INODE_SIZE + inode->i_extra_isize +
 738                                                                 sizeof(__u32))
 739                 goto write_ea_block;
 740
 741         /* Write the inode EA */
 742         ea_inode_magic = EXT2_EXT_ATTR_MAGIC;
 743         memcpy(((char *) inode) + EXT2_GOOD_OLD_INODE_SIZE +
 744                inode->i_extra_isize, &ea_inode_magic, sizeof(__u32));
 745         storage_size = inode_size - EXT2_GOOD_OLD_INODE_SIZE -
 746                                 inode->i_extra_isize - sizeof(__u32);
 747         start = ((char *) inode) + EXT2_GOOD_OLD_INODE_SIZE +
 748                                 inode->i_extra_isize + sizeof(__u32);
 749
 750         err = write_xattrs_to_buffer(fs, handle->attrs, handle->ibody_count,
 751                                      start, storage_size, 0, 0);
 752         if (err)
 753                 goto out;
 754 write_ea_block:
 755         /* Are we done? */
 756         if (handle->ibody_count == handle->count &&
 757             !ext2fs_file_acl_block(fs, EXT2_INODE(inode)))
 758                 goto skip_ea_block;
 759
 760         /* Write the EA block */
 761         err = ext2fs_get_memzero(fs->blocksize, &block_buf);
 762         if (err)
 763                 goto out;
 764
 765         storage_size = fs->blocksize - sizeof(struct ext2_ext_attr_header);
 766         start = block_buf + sizeof(struct ext2_ext_attr_header);
 767
 768         err = write_xattrs_to_buffer(fs, handle->attrs + handle->ibody_count,
 769                                      handle->count - handle->ibody_count, start,
 770                                      storage_size, start - block_buf, 1);
 771         if (err)
 772                 goto out2;
 773
 774         /* Write a header on the EA block */
 775         header = (struct ext2_ext_attr_header *) block_buf;
 776         header->h_magic = EXT2_EXT_ATTR_MAGIC;
 777         header->h_refcount = 1;
 778         header->h_blocks = 1;
 779
 780         /* Get a new block for writing */
 781         err = prep_ea_block_for_write(fs, handle->ino, inode);
 782         if (err)
 783                 goto out2;
 784
 785         /* Finally, write the new EA block */
 786         blk = ext2fs_file_acl_block(fs, EXT2_INODE(inode));
 787         err = ext2fs_write_ext_attr3(fs, blk, block_buf, handle->ino);
 788         if (err)
 789                 goto out2;
 790
 791 skip_ea_block:
 792         blk = ext2fs_file_acl_block(fs, (struct ext2_inode *)inode);
 793         if (!block_buf && blk) {
 794                 /* xattrs shrunk, free the block */
 795                 err = ext2fs_free_ext_attr(fs, handle->ino, inode);
 796                 if (err)
 797                         goto out;
 798         }
 799
 800         /* Write the inode */
 801         err = ext2fs_write_inode_full(fs, handle->ino, EXT2_INODE(inode),
 802                                       inode_size);
 803         if (err)
 804                 goto out2;
 805
 806 out2:
 807         ext2fs_free_mem(&block_buf);
 808 out:
 809         ext2fs_free_mem(&inode);
 810         return err;
 811 }
 812
 813 static errcode_t read_xattrs_from_buffer(struct ext2_xattr_handle *handle,
 814                                          struct ext2_inode_large *inode,
 815                                          struct ext2_ext_attr_entry *entries,
 816                                          unsigned int storage_size,
 817                                          char *value_start)
 818 {
 819         struct ext2_xattr *x;
 820         struct ext2_ext_attr_entry *entry, *end;
 821         const char *prefix;
 822         unsigned int remain, prefix_len;
 823         errcode_t err;
 824         unsigned int values_size = storage_size +
 825                         ((char *)entries - value_start);
 826
 827         /* find the end */
 828         end = entries;
 829         remain = storage_size;
 830         while (remain >= sizeof(struct ext2_ext_attr_entry) &&
 831                !EXT2_EXT_IS_LAST_ENTRY(end)) {
 832
 833                 /* header eats this space */
 834                 remain -= sizeof(struct ext2_ext_attr_entry);
 835
 836                 /* is attribute name valid? */
 837                 if (EXT2_EXT_ATTR_SIZE(end->e_name_len) > remain)
 838                         return EXT2_ET_EA_BAD_NAME_LEN;
 839
 840                 /* attribute len eats this space */
 841                 remain -= EXT2_EXT_ATTR_SIZE(end->e_name_len);
 842                 end = EXT2_EXT_ATTR_NEXT(end);
 843         }
 844
 845         entry = entries;
 846         remain = storage_size;
 847         while (remain >= sizeof(struct ext2_ext_attr_entry) &&
 848                !EXT2_EXT_IS_LAST_ENTRY(entry)) {
 849
 850                 /* Allocate space for more attrs? */
 851                 if (handle->count == handle->capacity) {
 852                         err = ext2fs_xattrs_expand(handle, 4);
 853                         if (err)
 854                                 return err;
 855                 }
 856
 857                 x = handle->attrs + handle->count;
 858
 859                 /* header eats this space */
 860                 remain -= sizeof(struct ext2_ext_attr_entry);
 861
 862                 /* attribute len eats this space */
 863                 remain -= EXT2_EXT_ATTR_SIZE(entry->e_name_len);
 864
 865                 /* Extract name */
 866                 prefix = find_ea_prefix(entry->e_name_index);
 867                 prefix_len = (prefix ? strlen(prefix) : 0);
 868                 err = ext2fs_get_memzero(entry->e_name_len + prefix_len + 1,
 869                                          &x->name);
 870                 if (err)
 871                         return err;
 872                 if (prefix)
 873                         memcpy(x->name, prefix, prefix_len);
 874                 if (entry->e_name_len)
 875                         memcpy(x->name + prefix_len,
 876                                (char *)entry + sizeof(*entry),
 877                                entry->e_name_len);
 878
 879                 /* Check & copy value */
 880                 if (!ext2fs_has_feature_ea_inode(handle->fs->super) &&
 881                     entry->e_value_inum != 0)
 882                         return EXT2_ET_BAD_EA_BLOCK_NUM;
 883
 884                 if (entry->e_value_inum == 0) {
 885                         if (entry->e_value_size > remain)
 886                                 return EXT2_ET_EA_BAD_VALUE_SIZE;
 887
 888                         if (entry->e_value_offs + entry->e_value_size > values_size)
 889                                 return EXT2_ET_EA_BAD_VALUE_OFFSET;
 890
 891                         if (entry->e_value_size > 0 &&
 892                             value_start + entry->e_value_offs <
 893                             (char *)end + sizeof(__u32))
 894                                 return EXT2_ET_EA_BAD_VALUE_OFFSET;
 895
 896                         remain -= entry->e_value_size;
 897
 898                         err = ext2fs_get_mem(entry->e_value_size, &x->value);
 899                         if (err)
 900                                 return err;
 901                         memcpy(x->value, value_start + entry->e_value_offs,
 902                                entry->e_value_size);
 903                 } else {
 904                         struct ext2_inode *ea_inode;
 905                         ext2_file_t ea_file;
 906
 907                         if (entry->e_value_offs != 0)
 908                                 return EXT2_ET_EA_BAD_VALUE_OFFSET;
 909
 910                         if (entry->e_value_size > (64 * 1024))
 911                                 return EXT2_ET_EA_BAD_VALUE_SIZE;
 912
 913                         err = ext2fs_get_mem(entry->e_value_size, &x->value);
 914                         if (err)
 915                                 return err;
 916
 917                         err = ext2fs_file_open(handle->fs, entry->e_value_inum,
 918                                                0, &ea_file);
 919                         if (err)
 920                                 return err;
 921
 922                         ea_inode = ext2fs_file_get_inode(ea_file);
 923                         if ((ea_inode->i_flags & EXT4_INLINE_DATA_FL) ||
 924                             !(ea_inode->i_flags & EXT4_EA_INODE_FL) ||
 925                             ea_inode->i_links_count == 0)
 926                                 err = EXT2_ET_EA_INODE_CORRUPTED;
 927                         else if (ext2fs_file_get_size(ea_file) !=
 928                             entry->e_value_size)
 929                                 err = EXT2_ET_EA_BAD_VALUE_SIZE;
 930                         else
 931                                 err = ext2fs_file_read(ea_file, x->value,
 932                                                        entry->e_value_size, 0);
 933                         ext2fs_file_close(ea_file);
 934                         if (err)
 935                                 return err;
 936                 }
 937
 938                 x->ea_ino = entry->e_value_inum;
 939                 x->value_len = entry->e_value_size;
 940
 941                 /* e_hash may be 0 in older inode's ea */
 942                 if (entry->e_hash != 0) {
 943                         __u32 hash;
 944                         void *data = (entry->e_value_inum != 0) ?
 945                                         0 : value_start + entry->e_value_offs;
 946
 947                         err = ext2fs_ext_attr_hash_entry2(handle->fs, entry,
 948                                                           data, &hash);
 949                         if (err)
 950                                 return err;
 951                         if (entry->e_hash != hash) {
 952                                 struct ext2_inode child;
 953
 954                                 /* Check whether this is an old Lustre-style
 955                                  * ea_inode reference.
 956                                  */
 957                                 err = ext2fs_read_inode(handle->fs,
 958                                                         entry->e_value_inum,
 959                                                         &child);
 960                                 if (err)
 961                                         return err;
 962                                 if (child.i_mtime != handle->ino ||
 963                                     child.i_generation != inode->i_generation)
 964                                         return EXT2_ET_BAD_EA_HASH;
 965                         }
 966                 }
 967
 968                 handle->count++;
 969                 entry = EXT2_EXT_ATTR_NEXT(entry);
 970         }
 971
 972         return 0;
 973 }
 974
 975 static void xattrs_free_keys(struct ext2_xattr_handle *h)
 976 {
 977         struct ext2_xattr *a = h->attrs;
 978         int i;
 979
 980         for (i = 0; i < h->capacity; i++) {
 981                 if (a[i].name)
 982                         ext2fs_free_mem(&a[i].name);
 983                 if (a[i].value)
 984                         ext2fs_free_mem(&a[i].value);
 985         }
 986         h->count = 0;
 987         h->ibody_count = 0;
 988 }
 989
 990 errcode_t ext2fs_xattrs_read(struct ext2_xattr_handle *handle)
 991 {
 992         struct ext2_inode_large *inode;
 993         struct ext2_ext_attr_header *header;
 994         __u32 ea_inode_magic;
 995         unsigned int storage_size;
 996         char *start, *block_buf = NULL;
 997         blk64_t blk;
 998         size_t i;
 999         errcode_t err;
1000
1001         EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EA_HANDLE);
1002         i = EXT2_INODE_SIZE(handle->fs->super);
1003         if (i < sizeof(*inode))
1004                 i = sizeof(*inode);
1005         err = ext2fs_get_memzero(i, &inode);
1006         if (err)
1007                 return err;
1008
1009         err = ext2fs_read_inode_full(handle->fs, handle->ino,
1010                                      (struct ext2_inode *)inode,
1011                                      EXT2_INODE_SIZE(handle->fs->super));
1012         if (err)
1013                 goto out;
1014
1015         xattrs_free_keys(handle);
1016
1017         /* Does the inode have space for EA? */
1018         if (inode->i_extra_isize < sizeof(inode->i_extra_isize) ||
1019             EXT2_INODE_SIZE(handle->fs->super) <= EXT2_GOOD_OLD_INODE_SIZE +
1020                                                   inode->i_extra_isize +
1021                                                   sizeof(__u32))
1022                 goto read_ea_block;
1023         if (inode->i_extra_isize & 3) {
1024                 err = EXT2_ET_INODE_CORRUPTED;
1025                 goto out;
1026         }
1027
1028         /* Look for EA in the inode */
1029         memcpy(&ea_inode_magic, ((char *) inode) + EXT2_GOOD_OLD_INODE_SIZE +
1030                inode->i_extra_isize, sizeof(__u32));
1031         if (ea_inode_magic == EXT2_EXT_ATTR_MAGIC) {
1032                 storage_size = EXT2_INODE_SIZE(handle->fs->super) -
1033                         EXT2_GOOD_OLD_INODE_SIZE - inode->i_extra_isize -
1034                         sizeof(__u32);
1035                 start = ((char *) inode) + EXT2_GOOD_OLD_INODE_SIZE +
1036                         inode->i_extra_isize + sizeof(__u32);
1037
1038                 err = read_xattrs_from_buffer(handle, inode,
1039                                         (struct ext2_ext_attr_entry *) start,
1040                                         storage_size, start);
1041                 if (err)
1042                         goto out;
1043
1044                 handle->ibody_count = handle->count;
1045         }
1046
1047 read_ea_block:
1048         /* Look for EA in a separate EA block */
1049         blk = ext2fs_file_acl_block(handle->fs, (struct ext2_inode *)inode);
1050         if (blk != 0) {
1051                 if ((blk < handle->fs->super->s_first_data_block) ||
1052                     (blk >= ext2fs_blocks_count(handle->fs->super))) {
1053                         err = EXT2_ET_BAD_EA_BLOCK_NUM;
1054                         goto out;
1055                 }
1056
1057                 err = ext2fs_get_mem(handle->fs->blocksize, &block_buf);
1058                 if (err)
1059                         goto out;
1060
1061                 err = ext2fs_read_ext_attr3(handle->fs, blk, block_buf,
1062                                             handle->ino);
1063                 if (err)
1064                         goto out3;
1065
1066                 /* We only know how to deal with v2 EA blocks */
1067                 header = (struct ext2_ext_attr_header *) block_buf;
1068                 if (header->h_magic != EXT2_EXT_ATTR_MAGIC) {
1069                         err = EXT2_ET_BAD_EA_HEADER;
1070                         goto out3;
1071                 }
1072
1073                 /* Read EAs */
1074                 storage_size = handle->fs->blocksize -
1075                         sizeof(struct ext2_ext_attr_header);
1076                 start = block_buf + sizeof(struct ext2_ext_attr_header);
1077                 err = read_xattrs_from_buffer(handle, inode,
1078                                         (struct ext2_ext_attr_entry *) start,
1079                                         storage_size, block_buf);
1080                 if (err)
1081                         goto out3;
1082
1083                 ext2fs_free_mem(&block_buf);
1084         }
1085
1086         ext2fs_free_mem(&block_buf);
1087         ext2fs_free_mem(&inode);
1088         return 0;
1089
1090 out3:
1091         ext2fs_free_mem(&block_buf);
1092 out:
1093         ext2fs_free_mem(&inode);
1094         return err;
1095 }
1096
1097 errcode_t ext2fs_xattrs_iterate(struct ext2_xattr_handle *h,
1098                                 int (*func)(char *name, char *value,
1099                                             size_t value_len, void *data),
1100                                 void *data)
1101 {
1102         struct ext2_xattr *x;
1103         int dirty = 0;
1104         int ret;
1105
1106         EXT2_CHECK_MAGIC(h, EXT2_ET_MAGIC_EA_HANDLE);
1107         for (x = h->attrs; x < h->attrs + h->count; x++) {
1108                 ret = func(x->name, x->value, x->value_len, data);
1109                 if (ret & XATTR_CHANGED)
1110                         dirty = 1;
1111                 if (ret & XATTR_ABORT)
1112                         break;
1113         }
1114
1115         if (dirty)
1116                 return ext2fs_xattrs_write(h);
1117         return 0;
1118 }
1119
1120 errcode_t ext2fs_xattr_get(struct ext2_xattr_handle *h, const char *key,
1121                            void **value, size_t *value_len)
1122 {
1123         struct ext2_xattr *x;
1124         char *val;
1125         errcode_t err;
1126
1127         EXT2_CHECK_MAGIC(h, EXT2_ET_MAGIC_EA_HANDLE);
1128         for (x = h->attrs; x < h->attrs + h->count; x++) {
1129                 if (strcmp(x->name, key))
1130                         continue;
1131
1132                 if (!(h->flags & XATTR_HANDLE_FLAG_RAW) &&
1133                     ((strcmp(key, "system.posix_acl_default") == 0) ||
1134                      (strcmp(key, "system.posix_acl_access") == 0))) {
1135                         err = convert_disk_buffer_to_posix_acl(x->value, x->value_len,
1136                                                                value, value_len);
1137                         return err;
1138                 } else {
1139                         err = ext2fs_get_mem(x->value_len, &val);
1140                         if (err)
1141                                 return err;
1142                         memcpy(val, x->value, x->value_len);
1143                         *value = val;
1144                         *value_len = x->value_len;
1145                         return 0;
1146                 }
1147         }
1148
1149         return EXT2_ET_EA_KEY_NOT_FOUND;
1150 }
1151
1152 errcode_t ext2fs_xattr_inode_max_size(ext2_filsys fs, ext2_ino_t ino,
1153                                       size_t *size)
1154 {
1155         struct ext2_ext_attr_entry *entry;
1156         struct ext2_inode_large *inode;
1157         __u32 ea_inode_magic;
1158         unsigned int minoff;
1159         char *start;
1160         size_t i;
1161         errcode_t err;
1162
1163         i = EXT2_INODE_SIZE(fs->super);
1164         if (i < sizeof(*inode))
1165                 i = sizeof(*inode);
1166         err = ext2fs_get_memzero(i, &inode);
1167         if (err)
1168                 return err;
1169
1170         err = ext2fs_read_inode_full(fs, ino, (struct ext2_inode *)inode,
1171                                      EXT2_INODE_SIZE(fs->super));
1172         if (err)
1173                 goto out;
1174
1175         /* Does the inode have size for EA? */
1176         if (EXT2_INODE_SIZE(fs->super) <= EXT2_GOOD_OLD_INODE_SIZE +
1177                                                   inode->i_extra_isize +
1178                                                   sizeof(__u32)) {
1179                 err = EXT2_ET_INLINE_DATA_NO_SPACE;
1180                 goto out;
1181         }
1182
1183         minoff = EXT2_INODE_SIZE(fs->super) - sizeof(*inode) - sizeof(__u32);
1184         memcpy(&ea_inode_magic, ((char *) inode) + EXT2_GOOD_OLD_INODE_SIZE +
1185                inode->i_extra_isize, sizeof(__u32));
1186         if (ea_inode_magic == EXT2_EXT_ATTR_MAGIC) {
1187                 /* has xattrs.  calculate the size */
1188                 start= ((char *) inode) + EXT2_GOOD_OLD_INODE_SIZE +
1189                         inode->i_extra_isize + sizeof(__u32);
1190                 entry = (struct ext2_ext_attr_entry *) start;
1191                 while (!EXT2_EXT_IS_LAST_ENTRY(entry)) {
1192                         if (!entry->e_value_inum && entry->e_value_size) {
1193                                 unsigned int offs = entry->e_value_offs;
1194                                 if (offs < minoff)
1195                                         minoff = offs;
1196                         }
1197                         entry = EXT2_EXT_ATTR_NEXT(entry);
1198                 }
1199                 *size = minoff - ((char *)entry - (char *)start) - sizeof(__u32);
1200         } else {
1201                 /* no xattr.  return a maximum size */
1202                 *size = EXT2_EXT_ATTR_SIZE(minoff -
1203                                            EXT2_EXT_ATTR_LEN(strlen("data")) -
1204                                            EXT2_EXT_ATTR_ROUND - sizeof(__u32));
1205         }
1206
1207 out:
1208         ext2fs_free_mem(&inode);
1209         return err;
1210 }
1211
1212 static errcode_t xattr_create_ea_inode(ext2_filsys fs, const void *value,
1213                                        size_t value_len, ext2_ino_t *ea_ino)
1214 {
1215         struct ext2_inode inode;
1216         ext2_ino_t ino;
1217         ext2_file_t file;
1218         __u32 hash;
1219         errcode_t ret;
1220
1221         ret = ext2fs_new_inode(fs, 0, 0, 0, &ino);
1222         if (ret)
1223                 return ret;
1224
1225         memset(&inode, 0, sizeof(inode));
1226         inode.i_flags |= EXT4_EA_INODE_FL;
1227         if (ext2fs_has_feature_extents(fs->super))
1228                 inode.i_flags |= EXT4_EXTENTS_FL;
1229         inode.i_size = 0;
1230         inode.i_mode = LINUX_S_IFREG | 0600;
1231         inode.i_links_count = 1;
1232         ret = ext2fs_write_new_inode(fs, ino, &inode);
1233         if (ret)
1234                 return ret;
1235         /*
1236          * ref_count and hash utilize inode's i_*time fields.
1237          * ext2fs_write_new_inode() call above initializes these fields with
1238          * current time. That's why ref count and hash updates are done
1239          * separately below.
1240          */
1241         ext2fs_set_ea_inode_ref(&inode, 1);
1242         hash = ext2fs_crc32c_le(fs->csum_seed, value, value_len);
1243         ext2fs_set_ea_inode_hash(&inode, hash);
1244
1245         ret = ext2fs_write_inode(fs, ino, &inode);
1246         if (ret)
1247                 return ret;
1248
1249         ret = ext2fs_file_open(fs, ino, EXT2_FILE_WRITE, &file);
1250         if (ret)
1251                 return ret;
1252         ret = ext2fs_file_write(file, value, value_len, NULL);
1253         ext2fs_file_close(file);
1254         if (ret)
1255                 return ret;
1256
1257         ext2fs_inode_alloc_stats2(fs, ino, 1 /* inuse */, 0 /* isdir */);
1258
1259         *ea_ino = ino;
1260         return 0;
1261 }
1262
1263 static errcode_t xattr_inode_dec_ref(ext2_filsys fs, ext2_ino_t ino)
1264 {
1265         struct ext2_inode_large inode;
1266         __u64 ref_count;
1267         errcode_t ret;
1268
1269         ret = ext2fs_read_inode_full(fs, ino, (struct ext2_inode *)&inode,
1270                                      sizeof(inode));
1271         if (ret)
1272                 goto out;
1273
1274         ref_count = ext2fs_get_ea_inode_ref(EXT2_INODE(&inode));
1275         ref_count--;
1276         ext2fs_set_ea_inode_ref(EXT2_INODE(&inode), ref_count);
1277
1278         if (ref_count)
1279                 goto write_out;
1280
1281         inode.i_links_count = 0;
1282         inode.i_dtime = fs->now ? fs->now : time(0);
1283
1284         ret = ext2fs_free_ext_attr(fs, ino, &inode);
1285         if (ret)
1286                 goto write_out;
1287
1288         if (ext2fs_inode_has_valid_blocks2(fs, (struct ext2_inode *)&inode)) {
1289                 ret = ext2fs_punch(fs, ino, (struct ext2_inode *)&inode, NULL,
1290                                    0, ~0ULL);
1291                 if (ret)
1292                         goto out;
1293         }
1294
1295         ext2fs_inode_alloc_stats2(fs, ino, -1 /* inuse */, 0 /* is_dir */);
1296
1297 write_out:
1298         ret = ext2fs_write_inode_full(fs, ino, (struct ext2_inode *)&inode,
1299                                       sizeof(inode));
1300 out:
1301         return ret;
1302 }
1303
1304 static errcode_t xattr_update_entry(ext2_filsys fs, struct ext2_xattr *x,
1305                                     const char *name, const void *value,
1306                                     size_t value_len, int in_inode)
1307 {
1308         ext2_ino_t ea_ino = 0;
1309         void *new_value = NULL;
1310         char *new_name = NULL;
1311         int name_len;
1312         errcode_t ret;
1313
1314         if (!x->name) {
1315                 name_len = strlen(name);
1316                 ret = ext2fs_get_mem(name_len + 1, &new_name);
1317                 if (ret)
1318                         goto fail;
1319                 memcpy(new_name, name, name_len + 1);
1320         }
1321
1322         ret = ext2fs_get_mem(value_len, &new_value);
1323         if (ret)
1324                 goto fail;
1325         memcpy(new_value, value, value_len);
1326
1327         if (in_inode) {
1328                 ret = xattr_create_ea_inode(fs, value, value_len, &ea_ino);
1329                 if (ret)
1330                         goto fail;
1331         }
1332
1333         if (x->ea_ino) {
1334                 ret = xattr_inode_dec_ref(fs, x->ea_ino);
1335                 if (ret)
1336                         goto fail;
1337         }
1338
1339         if (!x->name)
1340                 x->name = new_name;
1341
1342         if (x->value)
1343                 ext2fs_free_mem(&x->value);
1344         x->value = new_value;
1345         x->value_len = value_len;
1346         x->ea_ino = ea_ino;
1347         return 0;
1348 fail:
1349         if (new_name)
1350                 ext2fs_free_mem(&new_name);
1351         if (new_value)
1352                 ext2fs_free_mem(&new_value);
1353         if (ea_ino)
1354                 xattr_inode_dec_ref(fs, ea_ino);
1355         return ret;
1356 }
1357
1358 static int xattr_find_position(struct ext2_xattr *attrs, int count,
1359                                const char *name)
1360 {
1361         struct ext2_xattr *x;
1362         int i;
1363         const char *shortname, *x_shortname;
1364         int name_idx, x_name_idx;
1365         int shortname_len, x_shortname_len;
1366
1367         find_ea_index(name, &shortname, &name_idx);
1368         shortname_len = strlen(shortname);
1369
1370         for (i = 0, x = attrs; i < count; i++, x++) {
1371                 find_ea_index(x->name, &x_shortname, &x_name_idx);
1372                 if (name_idx < x_name_idx)
1373                         break;
1374                 if (name_idx > x_name_idx)
1375                         continue;
1376
1377                 x_shortname_len = strlen(x_shortname);
1378                 if (shortname_len < x_shortname_len)
1379                         break;
1380                 if (shortname_len > x_shortname_len)
1381                         continue;
1382
1383                 if (memcmp(shortname, x_shortname, shortname_len) <= 0)
1384                         break;
1385         }
1386         return i;
1387 }
1388
1389 static errcode_t xattr_array_update(struct ext2_xattr_handle *h,
1390                                     const char *name,
1391                                     const void *value, size_t value_len,
1392                                     int ibody_free, int block_free,
1393                                     int old_idx, int in_inode)
1394 {
1395         struct ext2_xattr tmp;
1396         int add_to_ibody;
1397         int needed;
1398         int name_len, name_idx;
1399         const char *shortname;
1400         int new_idx;
1401         int ret;
1402
1403         find_ea_index(name, &shortname, &name_idx);
1404         name_len = strlen(shortname);
1405
1406         needed = EXT2_EXT_ATTR_LEN(name_len);
1407         if (!in_inode)
1408                 needed += EXT2_EXT_ATTR_SIZE(value_len);
1409
1410         if (old_idx >= 0 && old_idx < h->ibody_count) {
1411                 ibody_free += EXT2_EXT_ATTR_LEN(name_len);
1412                 if (!h->attrs[old_idx].ea_ino)
1413                         ibody_free += EXT2_EXT_ATTR_SIZE(
1414                                                 h->attrs[old_idx].value_len);
1415         }
1416
1417         if (needed <= ibody_free) {
1418                 if (old_idx < 0) {
1419                         new_idx = h->ibody_count;
1420                         add_to_ibody = 1;
1421                         goto add_new;
1422                 }
1423
1424                 /* Update the existing entry. */
1425                 ret = xattr_update_entry(h->fs, &h->attrs[old_idx], name,
1426                                          value, value_len, in_inode);
1427                 if (ret)
1428                         return ret;
1429                 if (h->ibody_count <= old_idx) {
1430                         /* Move entry from block to the end of ibody. */
1431                         tmp = h->attrs[old_idx];
1432                         memmove(h->attrs + h->ibody_count + 1,
1433                                 h->attrs + h->ibody_count,
1434                                 (old_idx - h->ibody_count) * sizeof(*h->attrs));
1435                         h->attrs[h->ibody_count] = tmp;
1436                         h->ibody_count++;
1437                 }
1438                 return 0;
1439         }
1440
1441         if (h->ibody_count <= old_idx) {
1442                 block_free += EXT2_EXT_ATTR_LEN(name_len);
1443                 if (!h->attrs[old_idx].ea_ino)
1444                         block_free +=
1445                                 EXT2_EXT_ATTR_SIZE(h->attrs[old_idx].value_len);
1446         }
1447
1448         if (needed > block_free)
1449                 return EXT2_ET_EA_NO_SPACE;
1450
1451         if (old_idx >= 0) {
1452                 /* Update the existing entry. */
1453                 ret = xattr_update_entry(h->fs, &h->attrs[old_idx], name,
1454                                          value, value_len, in_inode);
1455                 if (ret)
1456                         return ret;
1457                 if (old_idx < h->ibody_count) {
1458                         /*
1459                          * Move entry from ibody to the block. Note that
1460                          * entries in the block are sorted.
1461                          */
1462                         new_idx = xattr_find_position(h->attrs + h->ibody_count,
1463                                 h->count - h->ibody_count, name);
1464                         new_idx += h->ibody_count - 1;
1465                         tmp = h->attrs[old_idx];
1466                         memmove(h->attrs + old_idx, h->attrs + old_idx + 1,
1467                                 (new_idx - old_idx) * sizeof(*h->attrs));
1468                         h->attrs[new_idx] = tmp;
1469                         h->ibody_count--;
1470                 }
1471                 return 0;
1472         }
1473
1474         new_idx = xattr_find_position(h->attrs + h->ibody_count,
1475                                       h->count - h->ibody_count, name);
1476         new_idx += h->ibody_count;
1477         add_to_ibody = 0;
1478
1479 add_new:
1480         if (h->count == h->capacity) {
1481                 ret = ext2fs_xattrs_expand(h, 4);
1482                 if (ret)
1483                         return ret;
1484         }
1485
1486         ret = xattr_update_entry(h->fs, &h->attrs[h->count], name, value,
1487                                  value_len, in_inode);
1488         if (ret)
1489                 return ret;
1490
1491         tmp = h->attrs[h->count];
1492         memmove(h->attrs + new_idx + 1, h->attrs + new_idx,
1493                 (h->count - new_idx)*sizeof(*h->attrs));
1494         h->attrs[new_idx] = tmp;
1495         if (add_to_ibody)
1496                 h->ibody_count++;
1497         h->count++;
1498         return 0;
1499 }
1500
1501 static int space_used(struct ext2_xattr *attrs, int count)
1502 {
1503         int total = 0;
1504         struct ext2_xattr *x;
1505         const char *shortname;
1506         int i, len, name_idx;
1507
1508         for (i = 0, x = attrs; i < count; i++, x++) {
1509                 find_ea_index(x->name, &shortname, &name_idx);
1510                 len = strlen(shortname);
1511                 total += EXT2_EXT_ATTR_LEN(len);
1512                 if (!x->ea_ino)
1513                         total += EXT2_EXT_ATTR_SIZE(x->value_len);
1514         }
1515         return total;
1516 }
1517
1518 /*
1519  * The minimum size of EA value when you start storing it in an external inode
1520  * size of block - size of header - size of 1 entry - 4 null bytes
1521  */
1522 #define EXT4_XATTR_MIN_LARGE_EA_SIZE(b) \
1523         ((b) - EXT2_EXT_ATTR_LEN(3) - sizeof(struct ext2_ext_attr_header) - 4)
1524
1525 errcode_t ext2fs_xattr_set(struct ext2_xattr_handle *h,
1526                            const char *name,
1527                            const void *value,
1528                            size_t value_len)
1529 {
1530         ext2_filsys fs = h->fs;
1531         const int inode_size = EXT2_INODE_SIZE(fs->super);
1532         struct ext2_inode_large *inode = NULL;
1533         struct ext2_xattr *x;
1534         char *new_value;
1535         int ibody_free, block_free;
1536         int in_inode = 0;
1537         int old_idx = -1;
1538         int extra_isize;
1539         errcode_t ret;
1540
1541         EXT2_CHECK_MAGIC(h, EXT2_ET_MAGIC_EA_HANDLE);
1542
1543         ret = ext2fs_get_mem(value_len, &new_value);
1544         if (ret)
1545                 return ret;
1546         if (!(h->flags & XATTR_HANDLE_FLAG_RAW) &&
1547             ((strcmp(name, "system.posix_acl_default") == 0) ||
1548              (strcmp(name, "system.posix_acl_access") == 0))) {
1549                 ret = convert_posix_acl_to_disk_buffer(value, value_len,
1550                                                        new_value, &value_len);
1551                 if (ret)
1552                         goto out;
1553         } else
1554                 memcpy(new_value, value, value_len);
1555
1556         /* Imitate kernel behavior by skipping update if value is the same. */
1557         for (x = h->attrs; x < h->attrs + h->count; x++) {
1558                 if (!strcmp(x->name, name)) {
1559                         if (!x->ea_ino && x->value_len == value_len &&
1560                             !memcmp(x->value, new_value, value_len)) {
1561                                 ret = 0;
1562                                 goto out;
1563                         }
1564                         old_idx = x - h->attrs;
1565                         break;
1566                 }
1567         }
1568
1569         ret = ext2fs_get_memzero(inode_size, &inode);
1570         if (ret)
1571                 goto out;
1572         ret = ext2fs_read_inode_full(fs, h->ino,
1573                                      (struct ext2_inode *)inode,
1574                                      inode_size);
1575         if (ret)
1576                 goto out;
1577         if (inode_size > EXT2_GOOD_OLD_INODE_SIZE) {
1578                 extra_isize = inode->i_extra_isize;
1579                 if (extra_isize == 0) {
1580                         extra_isize = fs->super->s_want_extra_isize;
1581                         if (extra_isize == 0)
1582                                 extra_isize = sizeof(__u32);
1583                 }
1584                 ibody_free = inode_size - EXT2_GOOD_OLD_INODE_SIZE;
1585                 ibody_free -= extra_isize;
1586                 /* Extended attribute magic and final null entry. */
1587                 ibody_free -= sizeof(__u32) * 2;
1588                 ibody_free -= space_used(h->attrs, h->ibody_count);
1589         } else
1590                 ibody_free = 0;
1591
1592         /* Inline data can only go to ibody. */
1593         if (strcmp(name, "system.data") == 0) {
1594                 if (h->ibody_count <= old_idx) {
1595                         ret = EXT2_ET_FILESYSTEM_CORRUPTED;
1596                         goto out;
1597                 }
1598                 ret = xattr_array_update(h, name, value, value_len, ibody_free,
1599                                          0 /* block_free */, old_idx,
1600                                          0 /* in_inode */);
1601                 if (ret)
1602                         goto out;
1603                 goto write_out;
1604         }
1605
1606         block_free = fs->blocksize;
1607         block_free -= sizeof(struct ext2_ext_attr_header);
1608         /* Final null entry. */
1609         block_free -= sizeof(__u32);
1610         block_free -= space_used(h->attrs + h->ibody_count,
1611                                  h->count - h->ibody_count);
1612
1613         if (ext2fs_has_feature_ea_inode(fs->super) &&
1614             value_len > EXT4_XATTR_MIN_LARGE_EA_SIZE(fs->blocksize))
1615                 in_inode = 1;
1616
1617         ret = xattr_array_update(h, name, value, value_len, ibody_free,
1618                                  block_free, old_idx, in_inode);
1619         if (ret == EXT2_ET_EA_NO_SPACE && !in_inode &&
1620             ext2fs_has_feature_ea_inode(fs->super))
1621                 ret = xattr_array_update(h, name, value, value_len, ibody_free,
1622                                  block_free, old_idx, 1 /* in_inode */);
1623         if (ret)
1624                 goto out;
1625
1626 write_out:
1627         ret = ext2fs_xattrs_write(h);
1628 out:
1629         if (inode)
1630                 ext2fs_free_mem(&inode);
1631         ext2fs_free_mem(&new_value);
1632         return ret;
1633 }
1634
1635 errcode_t ext2fs_xattr_remove(struct ext2_xattr_handle *handle,
1636                               const char *key)
1637 {
1638         struct ext2_xattr *x;
1639         struct ext2_xattr *end = handle->attrs + handle->count;
1640
1641         EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EA_HANDLE);
1642         for (x = handle->attrs; x < end; x++) {
1643                 if (strcmp(x->name, key) == 0) {
1644                         ext2fs_free_mem(&x->name);
1645                         ext2fs_free_mem(&x->value);
1646                         if (x->ea_ino)
1647                                 xattr_inode_dec_ref(handle->fs, x->ea_ino);
1648                         memmove(x, x + 1, (end - x - 1)*sizeof(*x));
1649                         memset(end - 1, 0, sizeof(*end));
1650                         if (x < handle->attrs + handle->ibody_count)
1651                                 handle->ibody_count--;
1652                         handle->count--;
1653                         return ext2fs_xattrs_write(handle);
1654                 }
1655         }
1656
1657         /* no key found, success! */
1658         return 0;
1659 }
1660
1661 errcode_t ext2fs_xattrs_open(ext2_filsys fs, ext2_ino_t ino,
1662                              struct ext2_xattr_handle **handle)
1663 {
1664         struct ext2_xattr_handle *h;
1665         errcode_t err;
1666
1667         if (!ext2fs_has_feature_xattr(fs->super) &&
1668             !ext2fs_has_feature_inline_data(fs->super))
1669                 return EXT2_ET_MISSING_EA_FEATURE;
1670
1671         err = ext2fs_get_memzero(sizeof(*h), &h);
1672         if (err)
1673                 return err;
1674
1675         h->magic = EXT2_ET_MAGIC_EA_HANDLE;
1676         h->capacity = 4;
1677         err = ext2fs_get_arrayzero(h->capacity, sizeof(struct ext2_xattr),
1678                                    &h->attrs);
1679         if (err) {
1680                 ext2fs_free_mem(&h);
1681                 return err;
1682         }
1683         h->count = 0;
1684         h->ino = ino;
1685         h->fs = fs;
1686         *handle = h;
1687         return 0;
1688 }
1689
1690 errcode_t ext2fs_xattrs_close(struct ext2_xattr_handle **handle)
1691 {
1692         struct ext2_xattr_handle *h = *handle;
1693
1694         EXT2_CHECK_MAGIC(h, EXT2_ET_MAGIC_EA_HANDLE);
1695         xattrs_free_keys(h);
1696         ext2fs_free_mem(&h->attrs);
1697         ext2fs_free_mem(handle);
1698         return 0;
1699 }
1700
1701 errcode_t ext2fs_xattrs_count(struct ext2_xattr_handle *handle, size_t *count)
1702 {
1703         EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EA_HANDLE);
1704         *count = handle->count;
1705         return 0;
1706 }
1707
1708 errcode_t ext2fs_xattrs_flags(struct ext2_xattr_handle *handle,
1709                               unsigned int *new_flags, unsigned int *old_flags)
1710 {
1711         EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EA_HANDLE);
1712         if (old_flags)
1713                 *old_flags = handle->flags;
1714         if (new_flags)
1715                 handle->flags = *new_flags;
1716         return 0;
1717 }