2 * Copyright (c) 2013 Grzegorz Kostka (kostka.grzegorz@gmail.com)
6 * Copyright (c) 2012 Martin Sucha
7 * Copyright (c) 2012 Frantisek Princ
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
14 * - Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * - Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * - The name of the author may not be used to endorse or promote products
20 * derived from this software without specific prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 /** @addtogroup lwext4
39 * @brief Ext4 data structure definitions.
45 #include "ext4_config.h"
46 #include "ext4_blockdev.h"
52 #define EXT4_CHECKSUM_CRC32C 1
55 * Structure of the super block
58 uint32_t inodes_count; /* I-nodes count */
59 uint32_t blocks_count_lo; /* Blocks count */
60 uint32_t reserved_blocks_count_lo; /* Reserved blocks count */
61 uint32_t free_blocks_count_lo; /* Free blocks count */
62 uint32_t free_inodes_count; /* Free inodes count */
63 uint32_t first_data_block; /* First Data Block */
64 uint32_t log_block_size; /* Block size */
65 uint32_t log_cluster_size; /* Obsoleted fragment size */
66 uint32_t blocks_per_group; /* Number of blocks per group */
67 uint32_t frags_per_group; /* Obsoleted fragments per group */
68 uint32_t inodes_per_group; /* Number of inodes per group */
69 uint32_t mount_time; /* Mount time */
70 uint32_t write_time; /* Write time */
71 uint16_t mount_count; /* Mount count */
72 uint16_t max_mount_count; /* Maximal mount count */
73 uint16_t magic; /* Magic signature */
74 uint16_t state; /* File system state */
75 uint16_t errors; /* Behavior when detecting errors */
76 uint16_t minor_rev_level; /* Minor revision level */
77 uint32_t last_check_time; /* Time of last check */
78 uint32_t check_interval; /* Maximum time between checks */
79 uint32_t creator_os; /* Creator OS */
80 uint32_t rev_level; /* Revision level */
81 uint16_t def_resuid; /* Default uid for reserved blocks */
82 uint16_t def_resgid; /* Default gid for reserved blocks */
84 /* Fields for EXT4_DYNAMIC_REV superblocks only. */
85 uint32_t first_inode; /* First non-reserved inode */
86 uint16_t inode_size; /* Size of inode structure */
87 uint16_t block_group_index; /* Block group index of this superblock */
88 uint32_t features_compatible; /* Compatible feature set */
89 uint32_t features_incompatible; /* Incompatible feature set */
90 uint32_t features_read_only; /* Readonly-compatible feature set */
91 uint8_t uuid[16]; /* 128-bit uuid for volume */
92 char volume_name[16]; /* Volume name */
93 char last_mounted[64]; /* Directory where last mounted */
94 uint32_t algorithm_usage_bitmap; /* For compression */
97 * Performance hints. Directory preallocation should only
98 * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
100 uint8_t s_prealloc_blocks; /* Number of blocks to try to preallocate */
101 uint8_t s_prealloc_dir_blocks; /* Number to preallocate for dirs */
102 uint16_t s_reserved_gdt_blocks; /* Per group desc for online growth */
105 * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
107 uint8_t journal_uuid[16]; /* UUID of journal superblock */
108 uint32_t journal_inode_number; /* Inode number of journal file */
109 uint32_t journal_dev; /* Device number of journal file */
110 uint32_t last_orphan; /* Head of list of inodes to delete */
111 uint32_t hash_seed[4]; /* HTREE hash seed */
112 uint8_t default_hash_version; /* Default hash version to use */
113 uint8_t journal_backup_type;
114 uint16_t desc_size; /* Size of group descriptor */
115 uint32_t default_mount_opts; /* Default mount options */
116 uint32_t first_meta_bg; /* First metablock block group */
117 uint32_t mkfs_time; /* When the filesystem was created */
118 uint32_t journal_blocks[17]; /* Backup of the journal inode */
120 /* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
121 uint32_t blocks_count_hi; /* Blocks count */
122 uint32_t reserved_blocks_count_hi; /* Reserved blocks count */
123 uint32_t free_blocks_count_hi; /* Free blocks count */
124 uint16_t min_extra_isize; /* All inodes have at least # bytes */
125 uint16_t want_extra_isize; /* New inodes should reserve # bytes */
126 uint32_t flags; /* Miscellaneous flags */
127 uint16_t raid_stride; /* RAID stride */
128 uint16_t mmp_interval; /* # seconds to wait in MMP checking */
129 uint64_t mmp_block; /* Block for multi-mount protection */
130 uint32_t raid_stripe_width; /* Blocks on all data disks (N * stride) */
131 uint8_t log_groups_per_flex; /* FLEX_BG group size */
132 uint8_t checksum_type;
133 uint16_t reserved_pad;
134 uint64_t kbytes_written; /* Number of lifetime kilobytes written */
135 uint32_t snapshot_inum; /* I-node number of active snapshot */
136 uint32_t snapshot_id; /* Sequential ID of active snapshot */
138 snapshot_r_blocks_count; /* Reserved blocks for active snapshot's
141 snapshot_list; /* I-node number of the head of the on-disk snapshot
143 uint32_t error_count; /* Number of file system errors */
144 uint32_t first_error_time; /* First time an error happened */
145 uint32_t first_error_ino; /* I-node involved in first error */
146 uint64_t first_error_block; /* Block involved of first error */
147 uint8_t first_error_func[32]; /* Function where the error happened */
148 uint32_t first_error_line; /* Line number where error happened */
149 uint32_t last_error_time; /* Most recent time of an error */
150 uint32_t last_error_ino; /* I-node involved in last error */
151 uint32_t last_error_line; /* Line number where error happened */
152 uint64_t last_error_block; /* Block involved of last error */
153 uint8_t last_error_func[32]; /* Function where the error happened */
154 uint8_t mount_opts[64];
155 uint32_t usr_quota_inum; /* inode for tracking user quota */
156 uint32_t grp_quota_inum; /* inode for tracking group quota */
157 uint32_t overhead_clusters; /* overhead blocks/clusters in fs */
158 uint32_t backup_bgs[2]; /* groups with sparse_super2 SBs */
159 uint8_t encrypt_algos[4]; /* Encryption algorithms in use */
160 uint8_t encrypt_pw_salt[16]; /* Salt used for string2key algorithm */
161 uint32_t lpf_ino; /* Location of the lost+found inode */
162 uint32_t padding[100]; /* Padding to the end of the block */
163 uint32_t checksum; /* crc32c(superblock) */
164 } __attribute__((packed));
166 #define EXT4_SUPERBLOCK_MAGIC 0xEF53
167 #define EXT4_SUPERBLOCK_SIZE 1024
168 #define EXT4_SUPERBLOCK_OFFSET 1024
170 #define EXT4_SUPERBLOCK_OS_LINUX 0
171 #define EXT4_SUPERBLOCK_OS_HURD 1
174 * Misc. filesystem flags
176 #define EXT4_SUPERBLOCK_FLAGS_SIGNED_HASH 0x0001
177 #define EXT4_SUPERBLOCK_FLAGS_UNSIGNED_HASH 0x0002
178 #define EXT4_SUPERBLOCK_FLAGS_TEST_FILESYS 0x0004
182 #define EXT4_SUPERBLOCK_STATE_VALID_FS 0x0001 /* Unmounted cleanly */
183 #define EXT4_SUPERBLOCK_STATE_ERROR_FS 0x0002 /* Errors detected */
184 #define EXT4_SUPERBLOCK_STATE_ORPHAN_FS 0x0004 /* Orphans being recovered */
187 * Behaviour when errors detected
189 #define EXT4_SUPERBLOCK_ERRORS_CONTINUE 1 /* Continue execution */
190 #define EXT4_SUPERBLOCK_ERRORS_RO 2 /* Remount fs read-only */
191 #define EXT4_SUPERBLOCK_ERRORS_PANIC 3 /* Panic */
192 #define EXT4_SUPERBLOCK_ERRORS_DEFAULT EXT4_ERRORS_CONTINUE
195 * Compatible features
197 #define EXT4_FCOM_DIR_PREALLOC 0x0001
198 #define EXT4_FCOM_IMAGIC_INODES 0x0002
199 #define EXT4_FCOM_HAS_JOURNAL 0x0004
200 #define EXT4_FCOM_EXT_ATTR 0x0008
201 #define EXT4_FCOM_RESIZE_INODE 0x0010
202 #define EXT4_FCOM_DIR_INDEX 0x0020
205 * Read-only compatible features
207 #define EXT4_FRO_COM_SPARSE_SUPER 0x0001
208 #define EXT4_FRO_COM_LARGE_FILE 0x0002
209 #define EXT4_FRO_COM_BTREE_DIR 0x0004
210 #define EXT4_FRO_COM_HUGE_FILE 0x0008
211 #define EXT4_FRO_COM_GDT_CSUM 0x0010
212 #define EXT4_FRO_COM_DIR_NLINK 0x0020
213 #define EXT4_FRO_COM_EXTRA_ISIZE 0x0040
214 #define EXT4_FRO_COM_QUOTA 0x0100
215 #define EXT4_FRO_COM_BIGALLOC 0x0200
216 #define EXT4_FRO_COM_METADATA_CSUM 0x0400
219 * Incompatible features
221 #define EXT4_FINCOM_COMPRESSION 0x0001
222 #define EXT4_FINCOM_FILETYPE 0x0002
223 #define EXT4_FINCOM_RECOVER 0x0004 /* Needs recovery */
224 #define EXT4_FINCOM_JOURNAL_DEV 0x0008 /* Journal device */
225 #define EXT4_FINCOM_META_BG 0x0010
226 #define EXT4_FINCOM_EXTENTS 0x0040 /* extents support */
227 #define EXT4_FINCOM_64BIT 0x0080
228 #define EXT4_FINCOM_MMP 0x0100
229 #define EXT4_FINCOM_FLEX_BG 0x0200
230 #define EXT4_FINCOM_EA_INODE 0x0400 /* EA in inode */
231 #define EXT4_FINCOM_DIRDATA 0x1000 /* data in dirent */
232 #define EXT4_FINCOM_BG_USE_META_CSUM 0x2000 /* use crc32c for bg */
233 #define EXT4_FINCOM_LARGEDIR 0x4000 /* >2GB or 3-lvl htree */
234 #define EXT4_FINCOM_INLINE_DATA 0x8000 /* data in inode */
237 * EXT2 supported feature set
239 #define EXT2_SUPPORTED_FCOM 0x0000
241 #define EXT2_SUPPORTED_FINCOM \
242 (EXT4_FINCOM_FILETYPE | EXT4_FINCOM_META_BG)
244 #define EXT2_SUPPORTED_FRO_COM \
245 (EXT4_FRO_COM_SPARSE_SUPER | \
246 EXT4_FRO_COM_LARGE_FILE)
249 * EXT3 supported feature set
251 #define EXT3_SUPPORTED_FCOM (EXT4_FCOM_DIR_INDEX)
253 #define EXT3_SUPPORTED_FINCOM \
254 (EXT4_FINCOM_FILETYPE | EXT4_FINCOM_META_BG)
256 #define EXT3_SUPPORTED_FRO_COM \
257 (EXT4_FRO_COM_SPARSE_SUPER | EXT4_FRO_COM_LARGE_FILE)
260 * EXT4 supported feature set
262 #define EXT4_SUPPORTED_FCOM (EXT4_FCOM_DIR_INDEX)
264 #define EXT4_SUPPORTED_FINCOM \
265 (EXT4_FINCOM_FILETYPE | EXT4_FINCOM_META_BG | \
266 EXT4_FINCOM_EXTENTS | EXT4_FINCOM_FLEX_BG | \
269 #define EXT4_SUPPORTED_FRO_COM \
270 (EXT4_FRO_COM_SPARSE_SUPER | \
271 EXT4_FRO_COM_METADATA_CSUM | \
272 EXT4_FRO_COM_LARGE_FILE | EXT4_FRO_COM_GDT_CSUM | \
273 EXT4_FRO_COM_DIR_NLINK | \
274 EXT4_FRO_COM_EXTRA_ISIZE | EXT4_FRO_COM_HUGE_FILE)
277 * RECOVER - journaling in lwext4 is not supported
278 * (probably won't be ever...)
279 * MMP - multi-mout protection (impossible scenario)
281 #define EXT_FINCOM_IGNORED \
282 EXT4_FINCOM_RECOVER | EXT4_FINCOM_MMP
285 /*TODO: Features incompatible to implement*/
286 #define EXT4_SUPPORTED_FINCOM
287 (EXT4_FINCOM_INLINE_DATA)
289 /*TODO: Features read only to implement*/
290 #define EXT4_SUPPORTED_FRO_COM
291 EXT4_FRO_COM_BIGALLOC |\
296 struct ext4_blockdev *bdev;
297 struct ext4_sblock sb;
299 uint64_t inode_block_limits[4];
300 uint64_t inode_blocks_per_level[4];
302 uint32_t last_inode_bg_id;
305 /* Inode table/bitmap not in use */
306 #define EXT4_BLOCK_GROUP_INODE_UNINIT 0x0001
307 /* Block bitmap not in use */
308 #define EXT4_BLOCK_GROUP_BLOCK_UNINIT 0x0002
309 /* On-disk itable initialized to zero */
310 #define EXT4_BLOCK_GROUP_ITABLE_ZEROED 0x0004
313 * Structure of a blocks group descriptor
316 uint32_t block_bitmap_lo; /* Blocks bitmap block */
317 uint32_t inode_bitmap_lo; /* Inodes bitmap block */
318 uint32_t inode_table_first_block_lo; /* Inodes table block */
319 uint16_t free_blocks_count_lo; /* Free blocks count */
320 uint16_t free_inodes_count_lo; /* Free inodes count */
321 uint16_t used_dirs_count_lo; /* Directories count */
322 uint16_t flags; /* EXT4_BG_flags (INODE_UNINIT, etc) */
323 uint32_t exclude_bitmap_lo; /* Exclude bitmap for snapshots */
324 uint16_t block_bitmap_csum_lo; /* crc32c(s_uuid+grp_num+bbitmap) LE */
325 uint16_t inode_bitmap_csum_lo; /* crc32c(s_uuid+grp_num+ibitmap) LE */
326 uint16_t itable_unused_lo; /* Unused inodes count */
327 uint16_t checksum; /* crc16(sb_uuid+group+desc) */
329 uint32_t block_bitmap_hi; /* Blocks bitmap block MSB */
330 uint32_t inode_bitmap_hi; /* I-nodes bitmap block MSB */
331 uint32_t inode_table_first_block_hi; /* I-nodes table block MSB */
332 uint16_t free_blocks_count_hi; /* Free blocks count MSB */
333 uint16_t free_inodes_count_hi; /* Free i-nodes count MSB */
334 uint16_t used_dirs_count_hi; /* Directories count MSB */
335 uint16_t itable_unused_hi; /* Unused inodes count MSB */
336 uint32_t exclude_bitmap_hi; /* Exclude bitmap block MSB */
337 uint16_t block_bitmap_csum_hi; /* crc32c(s_uuid+grp_num+bbitmap) BE */
338 uint16_t inode_bitmap_csum_hi; /* crc32c(s_uuid+grp_num+ibitmap) BE */
339 uint32_t reserved; /* Padding */
342 struct ext4_block_group_ref {
343 struct ext4_block block;
344 struct ext4_bgroup *block_group;
350 #define EXT4_MIN_BLOCK_GROUP_DESCRIPTOR_SIZE 32
351 #define EXT4_MAX_BLOCK_GROUP_DESCRIPTOR_SIZE 64
353 #define EXT4_MIN_BLOCK_SIZE 1024 /* 1 KiB */
354 #define EXT4_MAX_BLOCK_SIZE 65536 /* 64 KiB */
355 #define EXT4_REV0_INODE_SIZE 128
357 #define EXT4_INODE_BLOCK_SIZE 512
359 #define EXT4_INODE_DIRECT_BLOCK_COUNT 12
360 #define EXT4_INODE_INDIRECT_BLOCK EXT4_INODE_DIRECT_BLOCK_COUNT
361 #define EXT4_INODE_DOUBLE_INDIRECT_BLOCK (EXT4_INODE_INDIRECT_BLOCK + 1)
362 #define EXT4_INODE_TRIPPLE_INDIRECT_BLOCK (EXT4_INODE_DOUBLE_INDIRECT_BLOCK + 1)
363 #define EXT4_INODE_BLOCKS (EXT4_INODE_TRIPPLE_INDIRECT_BLOCK + 1)
364 #define EXT4_INODE_INDIRECT_BLOCK_COUNT \
365 (EXT4_INODE_BLOCKS - EXT4_INODE_DIRECT_BLOCK_COUNT)
368 * Structure of an inode on the disk
371 uint16_t mode; /* File mode */
372 uint16_t uid; /* Low 16 bits of owner uid */
373 uint32_t size_lo; /* Size in bytes */
374 uint32_t access_time; /* Access time */
375 uint32_t change_inode_time; /* I-node change time */
376 uint32_t modification_time; /* Modification time */
377 uint32_t deletion_time; /* Deletion time */
378 uint16_t gid; /* Low 16 bits of group id */
379 uint16_t links_count; /* Links count */
380 uint32_t blocks_count_lo; /* Blocks count */
381 uint32_t flags; /* File flags */
382 uint32_t unused_osd1; /* OS dependent - not used in HelenOS */
383 uint32_t blocks[EXT4_INODE_BLOCKS]; /* Pointers to blocks */
384 uint32_t generation; /* File version (for NFS) */
385 uint32_t file_acl_lo; /* File ACL */
387 uint32_t obso_faddr; /* Obsoleted fragment address */
391 uint16_t blocks_high;
392 uint16_t file_acl_high;
395 uint16_t checksum_lo; /* crc32c(uuid+inum+inode) LE */
405 } __attribute__((packed)) osd2;
407 uint16_t extra_isize;
408 uint16_t checksum_hi; /* crc32c(uuid+inum+inode) BE */
409 uint32_t ctime_extra; /* Extra change time (nsec << 2 | epoch) */
410 uint32_t mtime_extra; /* Extra Modification time (nsec << 2 | epoch) */
411 uint32_t atime_extra; /* Extra Access time (nsec << 2 | epoch) */
412 uint32_t crtime; /* File creation time */
414 crtime_extra; /* Extra file creation time (nsec << 2 | epoch) */
415 uint32_t version_hi; /* High 32 bits for 64-bit version */
416 } __attribute__((packed));
418 #define EXT4_INODE_MODE_FIFO 0x1000
419 #define EXT4_INODE_MODE_CHARDEV 0x2000
420 #define EXT4_INODE_MODE_DIRECTORY 0x4000
421 #define EXT4_INODE_MODE_BLOCKDEV 0x6000
422 #define EXT4_INODE_MODE_FILE 0x8000
423 #define EXT4_INODE_MODE_SOFTLINK 0xA000
424 #define EXT4_INODE_MODE_SOCKET 0xC000
425 #define EXT4_INODE_MODE_TYPE_MASK 0xF000
430 #define EXT4_INODE_FLAG_SECRM 0x00000001 /* Secure deletion */
431 #define EXT4_INODE_FLAG_UNRM 0x00000002 /* Undelete */
432 #define EXT4_INODE_FLAG_COMPR 0x00000004 /* Compress file */
433 #define EXT4_INODE_FLAG_SYNC 0x00000008 /* Synchronous updates */
434 #define EXT4_INODE_FLAG_IMMUTABLE 0x00000010 /* Immutable file */
435 #define EXT4_INODE_FLAG_APPEND 0x00000020 /* writes to file may only append */
436 #define EXT4_INODE_FLAG_NODUMP 0x00000040 /* do not dump file */
437 #define EXT4_INODE_FLAG_NOATIME 0x00000080 /* do not update atime */
439 /* Compression flags */
440 #define EXT4_INODE_FLAG_DIRTY 0x00000100
441 #define EXT4_INODE_FLAG_COMPRBLK \
442 0x00000200 /* One or more compressed clusters */
443 #define EXT4_INODE_FLAG_NOCOMPR 0x00000400 /* Don't compress */
444 #define EXT4_INODE_FLAG_ECOMPR 0x00000800 /* Compression error */
446 #define EXT4_INODE_FLAG_INDEX 0x00001000 /* hash-indexed directory */
447 #define EXT4_INODE_FLAG_IMAGIC 0x00002000 /* AFS directory */
448 #define EXT4_INODE_FLAG_JOURNAL_DATA \
449 0x00004000 /* File data should be journaled */
450 #define EXT4_INODE_FLAG_NOTAIL 0x00008000 /* File tail should not be merged */
451 #define EXT4_INODE_FLAG_DIRSYNC \
452 0x00010000 /* Dirsync behaviour (directories only) */
453 #define EXT4_INODE_FLAG_TOPDIR 0x00020000 /* Top of directory hierarchies */
454 #define EXT4_INODE_FLAG_HUGE_FILE 0x00040000 /* Set to each huge file */
455 #define EXT4_INODE_FLAG_EXTENTS 0x00080000 /* Inode uses extents */
456 #define EXT4_INODE_FLAG_EA_INODE 0x00200000 /* Inode used for large EA */
457 #define EXT4_INODE_FLAG_EOFBLOCKS 0x00400000 /* Blocks allocated beyond EOF */
458 #define EXT4_INODE_FLAG_RESERVED 0x80000000 /* reserved for ext4 lib */
460 #define EXT4_INODE_ROOT_INDEX 2
462 struct ext4_inode_ref {
463 struct ext4_block block;
464 struct ext4_inode *inode;
470 #define EXT4_DIRECTORY_FILENAME_LEN 255
472 /**@brief Directory entry types. */
473 enum { EXT4_DIRENTRY_UNKNOWN = 0,
474 EXT4_DIRENTRY_REG_FILE,
476 EXT4_DIRENTRY_CHRDEV,
477 EXT4_DIRENTRY_BLKDEV,
480 EXT4_DIRENTRY_SYMLINK };
482 #define EXT4_DIRENTRY_DIR_CSUM 0xDE
484 union ext4_dir_entry_ll_internal {
485 uint8_t name_length_high; /* Higher 8 bits of name length */
486 uint8_t inode_type; /* Type of referenced inode (in rev >= 0.5) */
487 } __attribute__((packed));
490 * Linked list directory entry structure
492 struct ext4_dir_entry_ll {
493 uint32_t inode; /* I-node for the entry */
494 uint16_t entry_length; /* Distance to the next directory entry */
495 uint8_t name_length; /* Lower 8 bits of name length */
497 union ext4_dir_entry_ll_internal in;
499 uint8_t name[EXT4_DIRECTORY_FILENAME_LEN]; /* Entry name */
500 } __attribute__((packed));
502 struct ext4_dir_iterator {
503 struct ext4_inode_ref *inode_ref;
504 struct ext4_block current_block;
505 uint64_t current_offset;
506 struct ext4_dir_entry_ll *current;
509 struct ext4_dir_search_result {
510 struct ext4_block block;
511 struct ext4_dir_entry_ll *dentry;
514 /* Structures for indexed directory */
516 struct ext4_dir_idx_countlimit {
521 struct ext4_dir_idx_dot_entry {
523 uint16_t entry_length;
529 struct ext4_dir_idx_root_info {
530 uint32_t reserved_zero;
531 uint8_t hash_version;
533 uint8_t indirect_levels;
534 uint8_t unused_flags;
537 struct ext4_dir_idx_entry {
542 struct ext4_dir_idx_root {
543 struct ext4_dir_idx_dot_entry dots[2];
544 struct ext4_dir_idx_root_info info;
545 struct ext4_dir_idx_entry entries[];
548 struct ext4_fake_dir_entry {
550 uint16_t entry_length;
555 struct ext4_dir_idx_node {
556 struct ext4_fake_dir_entry fake;
557 struct ext4_dir_idx_entry entries[];
560 struct ext4_dir_idx_block {
561 struct ext4_block block;
562 struct ext4_dir_idx_entry *entries;
563 struct ext4_dir_idx_entry *position;
567 * This goes at the end of each htree block.
569 struct ext4_dir_idx_tail {
571 uint32_t checksum; /* crc32c(uuid+inum+dirblock) */
575 * This is a bogus directory entry at the end of each leaf block that
578 struct ext4_dir_entry_tail {
579 uint32_t reserved_zero1; /* Pretend to be unused */
580 uint16_t rec_len; /* 12 */
581 uint8_t reserved_zero2; /* Zero name length */
582 uint8_t reserved_ft; /* 0xDE, fake file type */
583 uint32_t checksum; /* crc32c(uuid+inum+dirblock) */
586 #define EXT4_DIRENT_TAIL(block, blocksize) \
587 ((struct ext4_dir_entry_tail *)(((char *)(block)) + ((blocksize) - \
588 sizeof(struct ext4_dir_entry_tail))))
590 #define EXT4_ERR_BAD_DX_DIR (-25000)
592 #define EXT4_LINK_MAX 65000
594 #define EXT4_BAD_INO 1
595 #define EXT4_ROOT_INO 2
596 #define EXT4_BOOT_LOADER_INO 5
597 #define EXT4_UNDEL_DIR_INO 6
598 #define EXT4_RESIZE_INO 7
599 #define EXT4_JOURNAL_INO 8
601 #define EXT4_GOOD_OLD_FIRST_INO 11
603 #define EXT4_EXT_UNWRITTEN_MASK (1L << 15)
605 #define EXT4_EXT_MAX_LEN_WRITTEN (1L << 15)
606 #define EXT4_EXT_MAX_LEN_UNWRITTEN \
607 (EXT4_EXT_MAX_LEN_WRITTEN - 1)
609 #define EXT4_EXT_GET_LEN(ex) to_le16((ex)->block_count)
610 #define EXT4_EXT_GET_LEN_UNWRITTEN(ex) \
611 (EXT4_EXT_GET_LEN(ex) &= ~(EXT4_EXT_UNWRITTEN_MASK))
612 #define EXT4_EXT_SET_LEN(ex, count) \
613 ((ex)->block_count = to_le16(count))
615 #define EXT4_EXT_IS_UNWRITTEN(ex) \
616 (EXT4_EXT_GET_LEN(ex) > EXT4_EXT_MAX_LEN_WRITTEN)
617 #define EXT4_EXT_SET_UNWRITTEN(ex) \
618 ((ex)->block_count |= to_le16(EXT4_EXT_UNWRITTEN_MASK))
619 #define EXT4_EXT_SET_WRITTEN(ex) \
620 ((ex)->block_count &= ~(to_le16(EXT4_EXT_UNWRITTEN_MASK)))
622 * This is the extent tail on-disk structure.
623 * All other extent structures are 12 bytes long. It turns out that
624 * block_size % 12 >= 4 for at least all powers of 2 greater than 512, which
625 * covers all valid ext4 block sizes. Therefore, this tail structure can be
626 * crammed into the end of the block without having to rebalance the tree.
628 struct ext4_extent_tail
630 uint32_t et_checksum; /* crc32c(uuid+inum+extent_block) */
634 * This is the extent on-disk structure.
635 * It's used at the bottom of the tree.
638 uint32_t first_block; /* First logical block extent covers */
639 uint16_t block_count; /* Number of blocks covered by extent */
640 uint16_t start_hi; /* High 16 bits of physical block */
641 uint32_t start_lo; /* Low 32 bits of physical block */
645 * This is index on-disk structure.
646 * It's used at all the levels except the bottom.
648 struct ext4_extent_index {
649 uint32_t first_block; /* Index covers logical blocks from 'block' */
652 * Pointer to the physical block of the next
653 * level. leaf or next index could be there
654 * high 16 bits of physical block
662 * Each block (leaves and indexes), even inode-stored has header.
664 struct ext4_extent_header {
666 uint16_t entries_count; /* Number of valid entries */
667 uint16_t max_entries_count; /* Capacity of store in entries */
668 uint16_t depth; /* Has tree real underlying blocks? */
669 uint32_t generation; /* generation of the tree */
676 typedef uint32_t ext4_lblk_t;
677 typedef uint64_t ext4_fsblk_t;
680 * Array of ext4_ext_path contains path to some extent.
681 * Creation/lookup routines use it for traversal/splitting/etc.
682 * Truncate uses it to simulate recursive walking.
684 struct ext4_extent_path {
685 ext4_fsblk_t p_block;
686 struct ext4_block block;
689 struct ext4_extent_header *header;
690 struct ext4_extent_index *index;
691 struct ext4_extent *extent;
696 #define EXT4_EXTENT_MAGIC 0xF30A
698 #define EXT4_EXTENT_FIRST(header) \
699 ((struct ext4_extent *)(((char *)(header)) + \
700 sizeof(struct ext4_extent_header)))
702 #define EXT4_EXTENT_FIRST_INDEX(header) \
703 ((struct ext4_extent_index *)(((char *)(header)) + \
704 sizeof(struct ext4_extent_header)))
707 * EXT_INIT_MAX_LEN is the maximum number of blocks we can have in an
708 * initialized extent. This is 2^15 and not (2^16 - 1), since we use the
709 * MSB of ee_len field in the extent datastructure to signify if this
710 * particular extent is an initialized extent or an uninitialized (i.e.
712 * EXT_UNINIT_MAX_LEN is the maximum number of blocks we can have in an
713 * uninitialized extent.
714 * If ee_len is <= 0x8000, it is an initialized extent. Otherwise, it is an
715 * uninitialized one. In other words, if MSB of ee_len is set, it is an
716 * uninitialized extent with only one special scenario when ee_len = 0x8000.
717 * In this case we can not have an uninitialized extent of zero length and
718 * thus we make it as a special case of initialized extent with 0x8000 length.
719 * This way we get better extent-to-group alignment for initialized extents.
720 * Hence, the maximum number of blocks we can have in an *initialized*
721 * extent is 2^15 (32768) and in an *uninitialized* extent is 2^15-1 (32767).
723 #define EXT_INIT_MAX_LEN (1L << 15)
724 #define EXT_UNWRITTEN_MAX_LEN (EXT_INIT_MAX_LEN - 1)
726 #define EXT_EXTENT_SIZE sizeof(struct ext4_extent)
727 #define EXT_INDEX_SIZE sizeof(struct ext4_extent_idx)
729 #define EXT_FIRST_EXTENT(__hdr__) \
730 ((struct ext4_extent *)(((char *)(__hdr__)) + \
731 sizeof(struct ext4_extent_header)))
732 #define EXT_FIRST_INDEX(__hdr__) \
733 ((struct ext4_extent_index *)(((char *)(__hdr__)) + \
734 sizeof(struct ext4_extent_header)))
735 #define EXT_HAS_FREE_INDEX(__path__) \
736 ((__path__)->header->entries_count < (__path__)->header->max_entries_count)
737 #define EXT_LAST_EXTENT(__hdr__) \
738 (EXT_FIRST_EXTENT((__hdr__)) + (__hdr__)->entries_count - 1)
739 #define EXT_LAST_INDEX(__hdr__) \
740 (EXT_FIRST_INDEX((__hdr__)) + (__hdr__)->entries_count - 1)
741 #define EXT_MAX_EXTENT(__hdr__) \
742 (EXT_FIRST_EXTENT((__hdr__)) + (__hdr__)->max_entries_count - 1)
743 #define EXT_MAX_INDEX(__hdr__) \
744 (EXT_FIRST_INDEX((__hdr__)) + (__hdr__)->max_entries_count - 1)
746 #define EXT4_EXTENT_TAIL_OFFSET(hdr) \
747 (sizeof(struct ext4_extent_header) + \
748 (sizeof(struct ext4_extent) * (hdr)->max_entries_count))
751 * ext4_ext_next_allocated_block:
752 * returns allocated block in subsequent extent or EXT_MAX_BLOCKS.
753 * NOTE: it considers block number from index entry as
754 * allocated block. Thus, index entries have to be consistent
757 #define EXT_MAX_BLOCKS (ext4_lblk_t) (-1)
759 #define IN_RANGE(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1)
762 /******************************************************************************/
764 /* EXT3 HTree directory indexing */
765 #define EXT2_HTREE_LEGACY 0
766 #define EXT2_HTREE_HALF_MD4 1
767 #define EXT2_HTREE_TEA 2
768 #define EXT2_HTREE_LEGACY_UNSIGNED 3
769 #define EXT2_HTREE_HALF_MD4_UNSIGNED 4
770 #define EXT2_HTREE_TEA_UNSIGNED 5
772 #define EXT2_HTREE_EOF 0x7FFFFFFFUL
774 struct ext4_hash_info {
777 uint32_t hash_version;
778 const uint32_t *seed;
781 /* Extended Attribute(EA) */
783 /* Magic value in attribute blocks */
784 #define EXT4_XATTR_MAGIC 0xEA020000
786 /* Maximum number of references to one attribute block */
787 #define EXT4_XATTR_REFCOUNT_MAX 1024
790 #define EXT4_XATTR_INDEX_USER 1
791 #define EXT4_XATTR_INDEX_POSIX_ACL_ACCESS 2
792 #define EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT 3
793 #define EXT4_XATTR_INDEX_TRUSTED 4
794 #define EXT4_XATTR_INDEX_LUSTRE 5
795 #define EXT4_XATTR_INDEX_SECURITY 6
796 #define EXT4_XATTR_INDEX_SYSTEM 7
797 #define EXT4_XATTR_INDEX_RICHACL 8
798 #define EXT4_XATTR_INDEX_ENCRYPTION 9
800 struct ext4_xattr_header {
801 uint32_t h_magic; /* magic number for identification */
802 uint32_t h_refcount; /* reference count */
803 uint32_t h_blocks; /* number of disk blocks used */
804 uint32_t h_hash; /* hash value of all attributes */
805 uint32_t h_checksum; /* crc32c(uuid+id+xattrblock) */
806 /* id = inum if refcount=1, blknum otherwise */
807 uint32_t h_reserved[3]; /* zero right now */
808 } __attribute__((packed));
810 struct ext4_xattr_ibody_header {
811 uint32_t h_magic; /* magic number for identification */
812 } __attribute__((packed));
814 struct ext4_xattr_entry {
815 uint8_t e_name_len; /* length of name */
816 uint8_t e_name_index; /* attribute name index */
817 uint16_t e_value_offs; /* offset in disk block of value */
818 uint32_t e_value_block; /* disk block attribute is stored on (n/i) */
819 uint32_t e_value_size; /* size of attribute value */
820 uint32_t e_hash; /* hash value of name and value */
821 } __attribute__((packed));
823 struct ext4_xattr_item {
824 /* This attribute should be stored in inode body */
833 RB_ENTRY(ext4_xattr_item) node;
836 struct ext4_xattr_ref {
838 struct ext4_block block;
839 struct ext4_inode_ref *inode_ref;
845 struct ext4_xattr_item *iter_from;
847 RB_HEAD(ext4_xattr_tree,
848 ext4_xattr_item) root;
851 #define EXT4_XATTR_ITERATE_CONT 0
852 #define EXT4_XATTR_ITERATE_STOP 1
853 #define EXT4_XATTR_ITERATE_PAUSE 2
855 #define EXT4_GOOD_OLD_INODE_SIZE 128
857 #define EXT4_XATTR_PAD_BITS 2
858 #define EXT4_XATTR_PAD (1<<EXT4_XATTR_PAD_BITS)
859 #define EXT4_XATTR_ROUND (EXT4_XATTR_PAD-1)
860 #define EXT4_XATTR_LEN(name_len) \
861 (((name_len) + EXT4_XATTR_ROUND + \
862 sizeof(struct ext4_xattr_entry)) & ~EXT4_XATTR_ROUND)
863 #define EXT4_XATTR_NEXT(entry) \
864 ((struct ext4_xattr_entry *)( \
865 (char *)(entry) + EXT4_XATTR_LEN((entry)->e_name_len)))
866 #define EXT4_XATTR_SIZE(size) \
867 (((size) + EXT4_XATTR_ROUND) & ~EXT4_XATTR_ROUND)
868 #define EXT4_XATTR_NAME(entry) \
869 ((char *)((entry) + 1))
871 #define EXT4_XATTR_IHDR(raw_inode) \
872 ((struct ext4_xattr_ibody_header *) \
873 ((char *)raw_inode + \
874 EXT4_GOOD_OLD_INODE_SIZE + \
875 (raw_inode)->extra_isize))
876 #define EXT4_XATTR_IFIRST(hdr) \
877 ((struct ext4_xattr_entry *)((hdr)+1))
879 #define EXT4_XATTR_BHDR(block) \
880 ((struct ext4_xattr_header *)((block)->data))
881 #define EXT4_XATTR_ENTRY(ptr) \
882 ((struct ext4_xattr_entry *)(ptr))
883 #define EXT4_XATTR_BFIRST(block) \
884 EXT4_XATTR_ENTRY(EXT4_XATTR_BHDR(block)+1)
885 #define EXT4_XATTR_IS_LAST_ENTRY(entry) \
886 (*(uint32_t *)(entry) == 0)
888 #define EXT4_ZERO_XATTR_VALUE ((void *)-1)
890 /*****************************************************************************/
892 #define EXT4_CRC32_INIT (0xFFFFFFFFUL)
894 /*****************************************************************************/
895 #ifdef CONFIG_BIG_ENDIAN
896 static inline uint64_t to_le64(uint64_t n)
898 return ((n & 0xff) << 56) | ((n & 0xff00) << 40) |
899 ((n & 0xff0000) << 24) | ((n & 0xff000000LL) << 8) |
900 ((n & 0xff00000000LL) >> 8) | ((n & 0xff0000000000LL) >> 24) |
901 ((n & 0xff000000000000LL) >> 40) |
902 ((n & 0xff00000000000000LL) >> 56);
905 static inline uint32_t to_le32(uint32_t n)
907 return ((n & 0xff) << 24) | ((n & 0xff00) << 8) |
908 ((n & 0xff0000) >> 8) | ((n & 0xff000000) >> 24);
911 static inline uint16_t to_le16(uint16_t n)
913 return ((n & 0xff) << 8) | ((n & 0xff00) >> 8);
917 #define to_le64(_n) _n
918 #define to_le32(_n) _n
919 #define to_le16(_n) _n
922 /****************************Access macros to ext4 structures*****************/
924 #define ext4_get32(s, f) to_le32((s)->f)
925 #define ext4_get16(s, f) to_le16((s)->f)
926 #define ext4_get8(s, f) (s)->f
928 #define ext4_set32(s, f, v) \
930 (s)->f = to_le32(v); \
932 #define ext4_set16(s, f, v) \
934 (s)->f = to_le16(v); \
937 (s, f, v) do { (s)->f = (v); } \
943 #define __unused __attribute__ ((__unused__))
948 #define offsetof(type, field) \
949 ((size_t)(&(((type *)0)->field)))
952 #endif /* EXT4_TYPES_H_ */