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.
49 #include "ext4_config.h"
50 #include "ext4_blockdev.h"
51 #include "misc/tree.h"
59 typedef uint32_t ext4_lblk_t;
60 typedef uint64_t ext4_fsblk_t;
63 #define EXT4_CHECKSUM_CRC32C 1
70 * Structure of the super block
73 uint32_t inodes_count; /* I-nodes count */
74 uint32_t blocks_count_lo; /* Blocks count */
75 uint32_t reserved_blocks_count_lo; /* Reserved blocks count */
76 uint32_t free_blocks_count_lo; /* Free blocks count */
77 uint32_t free_inodes_count; /* Free inodes count */
78 uint32_t first_data_block; /* First Data Block */
79 uint32_t log_block_size; /* Block size */
80 uint32_t log_cluster_size; /* Obsoleted fragment size */
81 uint32_t blocks_per_group; /* Number of blocks per group */
82 uint32_t frags_per_group; /* Obsoleted fragments per group */
83 uint32_t inodes_per_group; /* Number of inodes per group */
84 uint32_t mount_time; /* Mount time */
85 uint32_t write_time; /* Write time */
86 uint16_t mount_count; /* Mount count */
87 uint16_t max_mount_count; /* Maximal mount count */
88 uint16_t magic; /* Magic signature */
89 uint16_t state; /* File system state */
90 uint16_t errors; /* Behavior when detecting errors */
91 uint16_t minor_rev_level; /* Minor revision level */
92 uint32_t last_check_time; /* Time of last check */
93 uint32_t check_interval; /* Maximum time between checks */
94 uint32_t creator_os; /* Creator OS */
95 uint32_t rev_level; /* Revision level */
96 uint16_t def_resuid; /* Default uid for reserved blocks */
97 uint16_t def_resgid; /* Default gid for reserved blocks */
99 /* Fields for EXT4_DYNAMIC_REV superblocks only. */
100 uint32_t first_inode; /* First non-reserved inode */
101 uint16_t inode_size; /* Size of inode structure */
102 uint16_t block_group_index; /* Block group index of this superblock */
103 uint32_t features_compatible; /* Compatible feature set */
104 uint32_t features_incompatible; /* Incompatible feature set */
105 uint32_t features_read_only; /* Readonly-compatible feature set */
106 uint8_t uuid[UUID_SIZE]; /* 128-bit uuid for volume */
107 char volume_name[16]; /* Volume name */
108 char last_mounted[64]; /* Directory where last mounted */
109 uint32_t algorithm_usage_bitmap; /* For compression */
112 * Performance hints. Directory preallocation should only
113 * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
115 uint8_t s_prealloc_blocks; /* Number of blocks to try to preallocate */
116 uint8_t s_prealloc_dir_blocks; /* Number to preallocate for dirs */
117 uint16_t s_reserved_gdt_blocks; /* Per group desc for online growth */
120 * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
122 uint8_t journal_uuid[UUID_SIZE]; /* UUID of journal superblock */
123 uint32_t journal_inode_number; /* Inode number of journal file */
124 uint32_t journal_dev; /* Device number of journal file */
125 uint32_t last_orphan; /* Head of list of inodes to delete */
126 uint32_t hash_seed[4]; /* HTREE hash seed */
127 uint8_t default_hash_version; /* Default hash version to use */
128 uint8_t journal_backup_type;
129 uint16_t desc_size; /* Size of group descriptor */
130 uint32_t default_mount_opts; /* Default mount options */
131 uint32_t first_meta_bg; /* First metablock block group */
132 uint32_t mkfs_time; /* When the filesystem was created */
133 uint32_t journal_blocks[17]; /* Backup of the journal inode */
135 /* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
136 uint32_t blocks_count_hi; /* Blocks count */
137 uint32_t reserved_blocks_count_hi; /* Reserved blocks count */
138 uint32_t free_blocks_count_hi; /* Free blocks count */
139 uint16_t min_extra_isize; /* All inodes have at least # bytes */
140 uint16_t want_extra_isize; /* New inodes should reserve # bytes */
141 uint32_t flags; /* Miscellaneous flags */
142 uint16_t raid_stride; /* RAID stride */
143 uint16_t mmp_interval; /* # seconds to wait in MMP checking */
144 uint64_t mmp_block; /* Block for multi-mount protection */
145 uint32_t raid_stripe_width; /* Blocks on all data disks (N * stride) */
146 uint8_t log_groups_per_flex; /* FLEX_BG group size */
147 uint8_t checksum_type;
148 uint16_t reserved_pad;
149 uint64_t kbytes_written; /* Number of lifetime kilobytes written */
150 uint32_t snapshot_inum; /* I-node number of active snapshot */
151 uint32_t snapshot_id; /* Sequential ID of active snapshot */
153 snapshot_r_blocks_count; /* Reserved blocks for active snapshot's
156 snapshot_list; /* I-node number of the head of the on-disk snapshot
158 uint32_t error_count; /* Number of file system errors */
159 uint32_t first_error_time; /* First time an error happened */
160 uint32_t first_error_ino; /* I-node involved in first error */
161 uint64_t first_error_block; /* Block involved of first error */
162 uint8_t first_error_func[32]; /* Function where the error happened */
163 uint32_t first_error_line; /* Line number where error happened */
164 uint32_t last_error_time; /* Most recent time of an error */
165 uint32_t last_error_ino; /* I-node involved in last error */
166 uint32_t last_error_line; /* Line number where error happened */
167 uint64_t last_error_block; /* Block involved of last error */
168 uint8_t last_error_func[32]; /* Function where the error happened */
169 uint8_t mount_opts[64];
170 uint32_t usr_quota_inum; /* inode for tracking user quota */
171 uint32_t grp_quota_inum; /* inode for tracking group quota */
172 uint32_t overhead_clusters; /* overhead blocks/clusters in fs */
173 uint32_t backup_bgs[2]; /* groups with sparse_super2 SBs */
174 uint8_t encrypt_algos[4]; /* Encryption algorithms in use */
175 uint8_t encrypt_pw_salt[16]; /* Salt used for string2key algorithm */
176 uint32_t lpf_ino; /* Location of the lost+found inode */
177 uint32_t padding[100]; /* Padding to the end of the block */
178 uint32_t checksum; /* crc32c(superblock) */
183 #define EXT4_SUPERBLOCK_MAGIC 0xEF53
184 #define EXT4_SUPERBLOCK_SIZE 1024
185 #define EXT4_SUPERBLOCK_OFFSET 1024
187 #define EXT4_SUPERBLOCK_OS_LINUX 0
188 #define EXT4_SUPERBLOCK_OS_HURD 1
191 * Misc. filesystem flags
193 #define EXT4_SUPERBLOCK_FLAGS_SIGNED_HASH 0x0001
194 #define EXT4_SUPERBLOCK_FLAGS_UNSIGNED_HASH 0x0002
195 #define EXT4_SUPERBLOCK_FLAGS_TEST_FILESYS 0x0004
199 #define EXT4_SUPERBLOCK_STATE_VALID_FS 0x0001 /* Unmounted cleanly */
200 #define EXT4_SUPERBLOCK_STATE_ERROR_FS 0x0002 /* Errors detected */
201 #define EXT4_SUPERBLOCK_STATE_ORPHAN_FS 0x0004 /* Orphans being recovered */
204 * Behaviour when errors detected
206 #define EXT4_SUPERBLOCK_ERRORS_CONTINUE 1 /* Continue execution */
207 #define EXT4_SUPERBLOCK_ERRORS_RO 2 /* Remount fs read-only */
208 #define EXT4_SUPERBLOCK_ERRORS_PANIC 3 /* Panic */
209 #define EXT4_SUPERBLOCK_ERRORS_DEFAULT EXT4_ERRORS_CONTINUE
212 * Compatible features
214 #define EXT4_FCOM_DIR_PREALLOC 0x0001
215 #define EXT4_FCOM_IMAGIC_INODES 0x0002
216 #define EXT4_FCOM_HAS_JOURNAL 0x0004
217 #define EXT4_FCOM_EXT_ATTR 0x0008
218 #define EXT4_FCOM_RESIZE_INODE 0x0010
219 #define EXT4_FCOM_DIR_INDEX 0x0020
222 * Read-only compatible features
224 #define EXT4_FRO_COM_SPARSE_SUPER 0x0001
225 #define EXT4_FRO_COM_LARGE_FILE 0x0002
226 #define EXT4_FRO_COM_BTREE_DIR 0x0004
227 #define EXT4_FRO_COM_HUGE_FILE 0x0008
228 #define EXT4_FRO_COM_GDT_CSUM 0x0010
229 #define EXT4_FRO_COM_DIR_NLINK 0x0020
230 #define EXT4_FRO_COM_EXTRA_ISIZE 0x0040
231 #define EXT4_FRO_COM_QUOTA 0x0100
232 #define EXT4_FRO_COM_BIGALLOC 0x0200
233 #define EXT4_FRO_COM_METADATA_CSUM 0x0400
236 * Incompatible features
238 #define EXT4_FINCOM_COMPRESSION 0x0001
239 #define EXT4_FINCOM_FILETYPE 0x0002
240 #define EXT4_FINCOM_RECOVER 0x0004 /* Needs recovery */
241 #define EXT4_FINCOM_JOURNAL_DEV 0x0008 /* Journal device */
242 #define EXT4_FINCOM_META_BG 0x0010
243 #define EXT4_FINCOM_EXTENTS 0x0040 /* extents support */
244 #define EXT4_FINCOM_64BIT 0x0080
245 #define EXT4_FINCOM_MMP 0x0100
246 #define EXT4_FINCOM_FLEX_BG 0x0200
247 #define EXT4_FINCOM_EA_INODE 0x0400 /* EA in inode */
248 #define EXT4_FINCOM_DIRDATA 0x1000 /* data in dirent */
249 #define EXT4_FINCOM_BG_USE_META_CSUM 0x2000 /* use crc32c for bg */
250 #define EXT4_FINCOM_LARGEDIR 0x4000 /* >2GB or 3-lvl htree */
251 #define EXT4_FINCOM_INLINE_DATA 0x8000 /* data in inode */
254 * EXT2 supported feature set
256 #define EXT2_SUPPORTED_FCOM 0x0000
258 #define EXT2_SUPPORTED_FINCOM \
259 (EXT4_FINCOM_FILETYPE | EXT4_FINCOM_META_BG)
261 #define EXT2_SUPPORTED_FRO_COM \
262 (EXT4_FRO_COM_SPARSE_SUPER | \
263 EXT4_FRO_COM_LARGE_FILE)
266 * EXT3 supported feature set
268 #define EXT3_SUPPORTED_FCOM (EXT4_FCOM_DIR_INDEX)
270 #define EXT3_SUPPORTED_FINCOM \
271 (EXT4_FINCOM_FILETYPE | EXT4_FINCOM_META_BG)
273 #define EXT3_SUPPORTED_FRO_COM \
274 (EXT4_FRO_COM_SPARSE_SUPER | EXT4_FRO_COM_LARGE_FILE)
277 * EXT4 supported feature set
279 #define EXT4_SUPPORTED_FCOM (EXT4_FCOM_DIR_INDEX)
281 #define EXT4_SUPPORTED_FINCOM \
282 (EXT4_FINCOM_FILETYPE | EXT4_FINCOM_META_BG | \
283 EXT4_FINCOM_EXTENTS | EXT4_FINCOM_FLEX_BG | \
286 #define EXT4_SUPPORTED_FRO_COM \
287 (EXT4_FRO_COM_SPARSE_SUPER | \
288 EXT4_FRO_COM_METADATA_CSUM | \
289 EXT4_FRO_COM_LARGE_FILE | EXT4_FRO_COM_GDT_CSUM | \
290 EXT4_FRO_COM_DIR_NLINK | \
291 EXT4_FRO_COM_EXTRA_ISIZE | EXT4_FRO_COM_HUGE_FILE)
294 * RECOVER - journaling in lwext4 is not supported
295 * (probably won't be ever...)
296 * MMP - multi-mout protection (impossible scenario)
298 #define EXT_FINCOM_IGNORED \
299 EXT4_FINCOM_RECOVER | EXT4_FINCOM_MMP
302 /*TODO: Features incompatible to implement*/
303 #define EXT4_SUPPORTED_FINCOM
304 (EXT4_FINCOM_INLINE_DATA)
306 /*TODO: Features read only to implement*/
307 #define EXT4_SUPPORTED_FRO_COM
308 EXT4_FRO_COM_BIGALLOC |\
313 /* Inode table/bitmap not in use */
314 #define EXT4_BLOCK_GROUP_INODE_UNINIT 0x0001
315 /* Block bitmap not in use */
316 #define EXT4_BLOCK_GROUP_BLOCK_UNINIT 0x0002
317 /* On-disk itable initialized to zero */
318 #define EXT4_BLOCK_GROUP_ITABLE_ZEROED 0x0004
321 * Structure of a blocks group descriptor
324 uint32_t block_bitmap_lo; /* Blocks bitmap block */
325 uint32_t inode_bitmap_lo; /* Inodes bitmap block */
326 uint32_t inode_table_first_block_lo; /* Inodes table block */
327 uint16_t free_blocks_count_lo; /* Free blocks count */
328 uint16_t free_inodes_count_lo; /* Free inodes count */
329 uint16_t used_dirs_count_lo; /* Directories count */
330 uint16_t flags; /* EXT4_BG_flags (INODE_UNINIT, etc) */
331 uint32_t exclude_bitmap_lo; /* Exclude bitmap for snapshots */
332 uint16_t block_bitmap_csum_lo; /* crc32c(s_uuid+grp_num+bbitmap) LE */
333 uint16_t inode_bitmap_csum_lo; /* crc32c(s_uuid+grp_num+ibitmap) LE */
334 uint16_t itable_unused_lo; /* Unused inodes count */
335 uint16_t checksum; /* crc16(sb_uuid+group+desc) */
337 uint32_t block_bitmap_hi; /* Blocks bitmap block MSB */
338 uint32_t inode_bitmap_hi; /* I-nodes bitmap block MSB */
339 uint32_t inode_table_first_block_hi; /* I-nodes table block MSB */
340 uint16_t free_blocks_count_hi; /* Free blocks count MSB */
341 uint16_t free_inodes_count_hi; /* Free i-nodes count MSB */
342 uint16_t used_dirs_count_hi; /* Directories count MSB */
343 uint16_t itable_unused_hi; /* Unused inodes count MSB */
344 uint32_t exclude_bitmap_hi; /* Exclude bitmap block MSB */
345 uint16_t block_bitmap_csum_hi; /* crc32c(s_uuid+grp_num+bbitmap) BE */
346 uint16_t inode_bitmap_csum_hi; /* crc32c(s_uuid+grp_num+ibitmap) BE */
347 uint32_t reserved; /* Padding */
351 #define EXT4_MIN_BLOCK_GROUP_DESCRIPTOR_SIZE 32
352 #define EXT4_MAX_BLOCK_GROUP_DESCRIPTOR_SIZE 64
354 #define EXT4_MIN_BLOCK_SIZE 1024 /* 1 KiB */
355 #define EXT4_MAX_BLOCK_SIZE 65536 /* 64 KiB */
356 #define EXT4_REV0_INODE_SIZE 128
358 #define EXT4_INODE_BLOCK_SIZE 512
360 #define EXT4_INODE_DIRECT_BLOCK_COUNT 12
361 #define EXT4_INODE_INDIRECT_BLOCK EXT4_INODE_DIRECT_BLOCK_COUNT
362 #define EXT4_INODE_DOUBLE_INDIRECT_BLOCK (EXT4_INODE_INDIRECT_BLOCK + 1)
363 #define EXT4_INODE_TRIPPLE_INDIRECT_BLOCK (EXT4_INODE_DOUBLE_INDIRECT_BLOCK + 1)
364 #define EXT4_INODE_BLOCKS (EXT4_INODE_TRIPPLE_INDIRECT_BLOCK + 1)
365 #define EXT4_INODE_INDIRECT_BLOCK_COUNT \
366 (EXT4_INODE_BLOCKS - EXT4_INODE_DIRECT_BLOCK_COUNT)
368 #pragma pack(push, 1)
371 * Structure of an inode on the disk
374 uint16_t mode; /* File mode */
375 uint16_t uid; /* Low 16 bits of owner uid */
376 uint32_t size_lo; /* Size in bytes */
377 uint32_t access_time; /* Access time */
378 uint32_t change_inode_time; /* I-node change time */
379 uint32_t modification_time; /* Modification time */
380 uint32_t deletion_time; /* Deletion time */
381 uint16_t gid; /* Low 16 bits of group id */
382 uint16_t links_count; /* Links count */
383 uint32_t blocks_count_lo; /* Blocks count */
384 uint32_t flags; /* File flags */
385 uint32_t unused_osd1; /* OS dependent - not used in HelenOS */
386 uint32_t blocks[EXT4_INODE_BLOCKS]; /* Pointers to blocks */
387 uint32_t generation; /* File version (for NFS) */
388 uint32_t file_acl_lo; /* File ACL */
390 uint32_t obso_faddr; /* Obsoleted fragment address */
394 uint16_t blocks_high;
395 uint16_t file_acl_high;
398 uint16_t checksum_lo; /* crc32c(uuid+inum+inode) LE */
410 uint16_t extra_isize;
411 uint16_t checksum_hi; /* crc32c(uuid+inum+inode) BE */
412 uint32_t ctime_extra; /* Extra change time (nsec << 2 | epoch) */
413 uint32_t mtime_extra; /* Extra Modification time (nsec << 2 | epoch) */
414 uint32_t atime_extra; /* Extra Access time (nsec << 2 | epoch) */
415 uint32_t crtime; /* File creation time */
417 crtime_extra; /* Extra file creation time (nsec << 2 | epoch) */
418 uint32_t version_hi; /* High 32 bits for 64-bit version */
423 #define EXT4_INODE_MODE_FIFO 0x1000
424 #define EXT4_INODE_MODE_CHARDEV 0x2000
425 #define EXT4_INODE_MODE_DIRECTORY 0x4000
426 #define EXT4_INODE_MODE_BLOCKDEV 0x6000
427 #define EXT4_INODE_MODE_FILE 0x8000
428 #define EXT4_INODE_MODE_SOFTLINK 0xA000
429 #define EXT4_INODE_MODE_SOCKET 0xC000
430 #define EXT4_INODE_MODE_TYPE_MASK 0xF000
435 #define EXT4_INODE_FLAG_SECRM 0x00000001 /* Secure deletion */
436 #define EXT4_INODE_FLAG_UNRM 0x00000002 /* Undelete */
437 #define EXT4_INODE_FLAG_COMPR 0x00000004 /* Compress file */
438 #define EXT4_INODE_FLAG_SYNC 0x00000008 /* Synchronous updates */
439 #define EXT4_INODE_FLAG_IMMUTABLE 0x00000010 /* Immutable file */
440 #define EXT4_INODE_FLAG_APPEND 0x00000020 /* writes to file may only append */
441 #define EXT4_INODE_FLAG_NODUMP 0x00000040 /* do not dump file */
442 #define EXT4_INODE_FLAG_NOATIME 0x00000080 /* do not update atime */
444 /* Compression flags */
445 #define EXT4_INODE_FLAG_DIRTY 0x00000100
446 #define EXT4_INODE_FLAG_COMPRBLK \
447 0x00000200 /* One or more compressed clusters */
448 #define EXT4_INODE_FLAG_NOCOMPR 0x00000400 /* Don't compress */
449 #define EXT4_INODE_FLAG_ECOMPR 0x00000800 /* Compression error */
451 #define EXT4_INODE_FLAG_INDEX 0x00001000 /* hash-indexed directory */
452 #define EXT4_INODE_FLAG_IMAGIC 0x00002000 /* AFS directory */
453 #define EXT4_INODE_FLAG_JOURNAL_DATA \
454 0x00004000 /* File data should be journaled */
455 #define EXT4_INODE_FLAG_NOTAIL 0x00008000 /* File tail should not be merged */
456 #define EXT4_INODE_FLAG_DIRSYNC \
457 0x00010000 /* Dirsync behaviour (directories only) */
458 #define EXT4_INODE_FLAG_TOPDIR 0x00020000 /* Top of directory hierarchies */
459 #define EXT4_INODE_FLAG_HUGE_FILE 0x00040000 /* Set to each huge file */
460 #define EXT4_INODE_FLAG_EXTENTS 0x00080000 /* Inode uses extents */
461 #define EXT4_INODE_FLAG_EA_INODE 0x00200000 /* Inode used for large EA */
462 #define EXT4_INODE_FLAG_EOFBLOCKS 0x00400000 /* Blocks allocated beyond EOF */
463 #define EXT4_INODE_FLAG_RESERVED 0x80000000 /* reserved for ext4 lib */
465 #define EXT4_INODE_ROOT_INDEX 2
468 #define EXT4_DIRECTORY_FILENAME_LEN 255
470 /**@brief Directory entry types. */
471 enum { EXT4_DE_UNKNOWN = 0,
480 #define EXT4_DIRENTRY_DIR_CSUM 0xDE
482 #pragma pack(push, 1)
484 union ext4_dir_en_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) */
490 * Linked list directory entry structure
493 uint32_t inode; /* I-node for the entry */
494 uint16_t entry_len; /* Distance to the next directory entry */
495 uint8_t name_len; /* Lower 8 bits of name length */
497 union ext4_dir_en_internal in;
498 uint8_t name[]; /* Entry name */
501 /* Structures for indexed directory */
503 struct ext4_dir_idx_climit {
508 struct ext4_dir_idx_dot_en {
510 uint16_t entry_length;
516 struct ext4_dir_idx_rinfo {
517 uint32_t reserved_zero;
518 uint8_t hash_version;
520 uint8_t indirect_levels;
521 uint8_t unused_flags;
524 struct ext4_dir_idx_entry {
529 struct ext4_dir_idx_root {
530 struct ext4_dir_idx_dot_en dots[2];
531 struct ext4_dir_idx_rinfo info;
532 struct ext4_dir_idx_entry en[];
535 struct ext4_fake_dir_entry {
537 uint16_t entry_length;
542 struct ext4_dir_idx_node {
543 struct ext4_fake_dir_entry fake;
544 struct ext4_dir_idx_entry entries[];
548 * This goes at the end of each htree block.
550 struct ext4_dir_idx_tail {
552 uint32_t checksum; /* crc32c(uuid+inum+dirblock) */
556 * This is a bogus directory entry at the end of each leaf block that
559 struct ext4_dir_entry_tail {
560 uint32_t reserved_zero1; /* Pretend to be unused */
561 uint16_t rec_len; /* 12 */
562 uint8_t reserved_zero2; /* Zero name length */
563 uint8_t reserved_ft; /* 0xDE, fake file type */
564 uint32_t checksum; /* crc32c(uuid+inum+dirblock) */
569 #define EXT4_DIRENT_TAIL(block, blocksize) \
570 ((struct ext4_dir_entry_tail *)(((char *)(block)) + ((blocksize) - \
571 sizeof(struct ext4_dir_entry_tail))))
573 #define EXT4_ERR_BAD_DX_DIR (-25000)
575 #define EXT4_LINK_MAX 65000
577 #define EXT4_BAD_INO 1
578 #define EXT4_ROOT_INO 2
579 #define EXT4_BOOT_LOADER_INO 5
580 #define EXT4_UNDEL_DIR_INO 6
581 #define EXT4_RESIZE_INO 7
582 #define EXT4_JOURNAL_INO 8
584 #define EXT4_GOOD_OLD_FIRST_INO 11
586 #define EXT4_EXT_UNWRITTEN_MASK (1L << 15)
588 #define EXT4_EXT_MAX_LEN_WRITTEN (1L << 15)
589 #define EXT4_EXT_MAX_LEN_UNWRITTEN \
590 (EXT4_EXT_MAX_LEN_WRITTEN - 1)
592 #define EXT4_EXT_GET_LEN(ex) to_le16((ex)->block_count)
593 #define EXT4_EXT_GET_LEN_UNWRITTEN(ex) \
594 (EXT4_EXT_GET_LEN(ex) &= ~(EXT4_EXT_UNWRITTEN_MASK))
595 #define EXT4_EXT_SET_LEN(ex, count) \
596 ((ex)->block_count = to_le16(count))
598 #define EXT4_EXT_IS_UNWRITTEN(ex) \
599 (EXT4_EXT_GET_LEN(ex) > EXT4_EXT_MAX_LEN_WRITTEN)
600 #define EXT4_EXT_SET_UNWRITTEN(ex) \
601 ((ex)->block_count |= to_le16(EXT4_EXT_UNWRITTEN_MASK))
602 #define EXT4_EXT_SET_WRITTEN(ex) \
603 ((ex)->block_count &= ~(to_le16(EXT4_EXT_UNWRITTEN_MASK)))
605 #pragma pack(push, 1)
608 * This is the extent tail on-disk structure.
609 * All other extent structures are 12 bytes long. It turns out that
610 * block_size % 12 >= 4 for at least all powers of 2 greater than 512, which
611 * covers all valid ext4 block sizes. Therefore, this tail structure can be
612 * crammed into the end of the block without having to rebalance the tree.
614 struct ext4_extent_tail
616 uint32_t et_checksum; /* crc32c(uuid+inum+extent_block) */
620 * This is the extent on-disk structure.
621 * It's used at the bottom of the tree.
624 uint32_t first_block; /* First logical block extent covers */
625 uint16_t block_count; /* Number of blocks covered by extent */
626 uint16_t start_hi; /* High 16 bits of physical block */
627 uint32_t start_lo; /* Low 32 bits of physical block */
631 * This is index on-disk structure.
632 * It's used at all the levels except the bottom.
634 struct ext4_extent_index {
635 uint32_t first_block; /* Index covers logical blocks from 'block' */
638 * Pointer to the physical block of the next
639 * level. leaf or next index could be there
640 * high 16 bits of physical block
648 * Each block (leaves and indexes), even inode-stored has header.
650 struct ext4_extent_header {
652 uint16_t entries_count; /* Number of valid entries */
653 uint16_t max_entries_count; /* Capacity of store in entries */
654 uint16_t depth; /* Has tree real underlying blocks? */
655 uint32_t generation; /* generation of the tree */
661 #define EXT4_EXTENT_MAGIC 0xF30A
663 #define EXT4_EXTENT_FIRST(header) \
664 ((struct ext4_extent *)(((char *)(header)) + \
665 sizeof(struct ext4_extent_header)))
667 #define EXT4_EXTENT_FIRST_INDEX(header) \
668 ((struct ext4_extent_index *)(((char *)(header)) + \
669 sizeof(struct ext4_extent_header)))
672 * EXT_INIT_MAX_LEN is the maximum number of blocks we can have in an
673 * initialized extent. This is 2^15 and not (2^16 - 1), since we use the
674 * MSB of ee_len field in the extent datastructure to signify if this
675 * particular extent is an initialized extent or an uninitialized (i.e.
677 * EXT_UNINIT_MAX_LEN is the maximum number of blocks we can have in an
678 * uninitialized extent.
679 * If ee_len is <= 0x8000, it is an initialized extent. Otherwise, it is an
680 * uninitialized one. In other words, if MSB of ee_len is set, it is an
681 * uninitialized extent with only one special scenario when ee_len = 0x8000.
682 * In this case we can not have an uninitialized extent of zero length and
683 * thus we make it as a special case of initialized extent with 0x8000 length.
684 * This way we get better extent-to-group alignment for initialized extents.
685 * Hence, the maximum number of blocks we can have in an *initialized*
686 * extent is 2^15 (32768) and in an *uninitialized* extent is 2^15-1 (32767).
688 #define EXT_INIT_MAX_LEN (1L << 15)
689 #define EXT_UNWRITTEN_MAX_LEN (EXT_INIT_MAX_LEN - 1)
691 #define EXT_EXTENT_SIZE sizeof(struct ext4_extent)
692 #define EXT_INDEX_SIZE sizeof(struct ext4_extent_idx)
694 #define EXT_FIRST_EXTENT(__hdr__) \
695 ((struct ext4_extent *)(((char *)(__hdr__)) + \
696 sizeof(struct ext4_extent_header)))
697 #define EXT_FIRST_INDEX(__hdr__) \
698 ((struct ext4_extent_index *)(((char *)(__hdr__)) + \
699 sizeof(struct ext4_extent_header)))
700 #define EXT_HAS_FREE_INDEX(__path__) \
701 (to_le16((__path__)->header->entries_count) < \
702 to_le16((__path__)->header->max_entries_count))
703 #define EXT_LAST_EXTENT(__hdr__) \
704 (EXT_FIRST_EXTENT((__hdr__)) + to_le16((__hdr__)->entries_count) - 1)
705 #define EXT_LAST_INDEX(__hdr__) \
706 (EXT_FIRST_INDEX((__hdr__)) + to_le16((__hdr__)->entries_count) - 1)
707 #define EXT_MAX_EXTENT(__hdr__) \
708 (EXT_FIRST_EXTENT((__hdr__)) + to_le16((__hdr__)->max_entries_count) - 1)
709 #define EXT_MAX_INDEX(__hdr__) \
710 (EXT_FIRST_INDEX((__hdr__)) + to_le16((__hdr__)->max_entries_count) - 1)
712 #define EXT4_EXTENT_TAIL_OFFSET(hdr) \
713 (sizeof(struct ext4_extent_header) + \
714 (sizeof(struct ext4_extent) * to_le16((hdr)->max_entries_count)))
717 * ext4_ext_next_allocated_block:
718 * returns allocated block in subsequent extent or EXT_MAX_BLOCKS.
719 * NOTE: it considers block number from index entry as
720 * allocated block. Thus, index entries have to be consistent
723 #define EXT_MAX_BLOCKS (ext4_lblk_t) (-1)
725 #define IN_RANGE(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1)
728 /******************************************************************************/
730 /* EXT3 HTree directory indexing */
731 #define EXT2_HTREE_LEGACY 0
732 #define EXT2_HTREE_HALF_MD4 1
733 #define EXT2_HTREE_TEA 2
734 #define EXT2_HTREE_LEGACY_UNSIGNED 3
735 #define EXT2_HTREE_HALF_MD4_UNSIGNED 4
736 #define EXT2_HTREE_TEA_UNSIGNED 5
738 #define EXT2_HTREE_EOF 0x7FFFFFFFUL
741 /* Extended Attribute(EA) */
743 /* Magic value in attribute blocks */
744 #define EXT4_XATTR_MAGIC 0xEA020000
746 /* Maximum number of references to one attribute block */
747 #define EXT4_XATTR_REFCOUNT_MAX 1024
750 #define EXT4_XATTR_INDEX_USER 1
751 #define EXT4_XATTR_INDEX_POSIX_ACL_ACCESS 2
752 #define EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT 3
753 #define EXT4_XATTR_INDEX_TRUSTED 4
754 #define EXT4_XATTR_INDEX_LUSTRE 5
755 #define EXT4_XATTR_INDEX_SECURITY 6
756 #define EXT4_XATTR_INDEX_SYSTEM 7
757 #define EXT4_XATTR_INDEX_RICHACL 8
758 #define EXT4_XATTR_INDEX_ENCRYPTION 9
760 #pragma pack(push, 1)
762 struct ext4_xattr_header {
763 uint32_t h_magic; /* magic number for identification */
764 uint32_t h_refcount; /* reference count */
765 uint32_t h_blocks; /* number of disk blocks used */
766 uint32_t h_hash; /* hash value of all attributes */
767 uint32_t h_checksum; /* crc32c(uuid+id+xattrblock) */
768 /* id = inum if refcount=1, blknum otherwise */
769 uint32_t h_reserved[3]; /* zero right now */
772 struct ext4_xattr_ibody_header {
773 uint32_t h_magic; /* magic number for identification */
776 struct ext4_xattr_entry {
777 uint8_t e_name_len; /* length of name */
778 uint8_t e_name_index; /* attribute name index */
779 uint16_t e_value_offs; /* offset in disk block of value */
780 uint32_t e_value_block; /* disk block attribute is stored on (n/i) */
781 uint32_t e_value_size; /* size of attribute value */
782 uint32_t e_hash; /* hash value of name and value */
787 #define EXT4_GOOD_OLD_INODE_SIZE 128
789 /*****************************************************************************/
792 * JBD stores integers in big endian.
795 #define JBD_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */
798 * Descriptor block types:
801 #define JBD_DESCRIPTOR_BLOCK 1
802 #define JBD_COMMIT_BLOCK 2
803 #define JBD_SUPERBLOCK 3
804 #define JBD_SUPERBLOCK_V2 4
805 #define JBD_REVOKE_BLOCK 5
807 #pragma pack(push, 1)
810 * Standard header for all descriptor blocks:
823 #define JBD_CRC32_CHKSUM 1
824 #define JBD_MD5_CHKSUM 2
825 #define JBD_SHA1_CHKSUM 3
826 #define JBD_CRC32C_CHKSUM 4
828 #define JBD_CRC32_CHKSUM_SIZE 4
830 #define JBD_CHECKSUM_BYTES (32 / sizeof(uint32_t))
832 #pragma pack(push, 1)
835 * Commit block header for storing transactional checksums:
837 * NOTE: If FEATURE_COMPAT_CHECKSUM (checksum v1) is set, the h_chksum*
838 * fields are used to store a checksum of the descriptor and data blocks.
840 * If FEATURE_INCOMPAT_CSUM_V2 (checksum v2) is set, then the h_chksum
841 * field is used to store crc32c(uuid+commit_block). Each journal metadata
842 * block gets its own checksum, and data block checksums are stored in
843 * journal_block_tag (in the descriptor). The other h_chksum* fields are
846 * If FEATURE_INCOMPAT_CSUM_V3 is set, the descriptor block uses
847 * journal_block_tag3_t to store a full 32-bit checksum. Everything else
850 * Checksum v1, v2, and v3 are mutually exclusive features.
853 struct jbd_commit_header {
854 struct jbd_bhdr header;
858 uint32_t chksum[JBD_CHECKSUM_BYTES];
860 uint32_t commit_nsec;
864 * The block tag: used to describe a single buffer in the journal
866 struct jbd_block_tag3 {
867 uint32_t blocknr; /* The on-disk block number */
868 uint32_t flags; /* See below */
869 uint32_t blocknr_high; /* most-significant high 32bits. */
870 uint32_t checksum; /* crc32c(uuid+seq+block) */
873 struct jbd_block_tag {
874 uint32_t blocknr; /* The on-disk block number */
875 uint16_t checksum; /* truncated crc32c(uuid+seq+block) */
876 uint16_t flags; /* See below */
877 uint32_t blocknr_high; /* most-significant high 32bits. */
882 /* Definitions for the journal tag flags word: */
883 #define JBD_FLAG_ESCAPE 1 /* on-disk block is escaped */
884 #define JBD_FLAG_SAME_UUID 2 /* block has same uuid as previous */
885 #define JBD_FLAG_DELETED 4 /* block deleted by this transaction */
886 #define JBD_FLAG_LAST_TAG 8 /* last tag in this descriptor block */
888 #pragma pack(push, 1)
890 /* Tail of descriptor block, for checksumming */
891 struct jbd_block_tail {
896 * The revoke descriptor: used on disk to describe a series of blocks to
897 * be revoked from the log
899 struct jbd_revoke_header {
900 struct jbd_bhdr header;
901 uint32_t count; /* Count of bytes used in the block */
904 /* Tail of revoke block, for checksumming */
905 struct jbd_revoke_tail {
911 #define JBD_USERS_MAX 48
912 #define JBD_USERS_SIZE (UUID_SIZE * JBD_USERS_MAX)
914 #pragma pack(push, 1)
917 * The journal superblock. All fields are in big-endian byte order.
921 struct jbd_bhdr header;
924 /* Static information describing the journal */
925 uint32_t blocksize; /* journal device blocksize */
926 uint32_t maxlen; /* total blocks in journal file */
927 uint32_t first; /* first block of log information */
930 /* Dynamic information describing the current state of the log */
931 uint32_t sequence; /* first commit ID expected in log */
932 uint32_t start; /* blocknr of start of log */
935 /* Error value, as set by journal_abort(). */
939 /* Remaining fields are only valid in a version-2 superblock */
940 uint32_t feature_compat; /* compatible feature set */
941 uint32_t feature_incompat; /* incompatible feature set */
942 uint32_t feature_ro_compat; /* readonly-compatible feature set */
944 uint8_t uuid[UUID_SIZE]; /* 128-bit uuid for journal */
947 uint32_t nr_users; /* Nr of filesystems sharing log */
949 uint32_t dynsuper; /* Blocknr of dynamic superblock copy*/
952 uint32_t max_transaction; /* Limit of journal blocks per trans.*/
953 uint32_t max_trandata; /* Limit of data blocks per trans. */
956 uint8_t checksum_type; /* checksum type */
958 uint32_t padding[42];
959 uint32_t checksum; /* crc32c(superblock) */
962 uint8_t users[JBD_USERS_SIZE]; /* ids of all fs'es sharing the log */
969 #define JBD_SUPERBLOCK_SIZE sizeof(struct jbd_sb)
971 #define JBD_HAS_COMPAT_FEATURE(jsb,mask) \
972 ((jsb)->header.blocktype >= to_be32(2) && \
973 ((jsb)->feature_compat & to_be32((mask))))
974 #define JBD_HAS_RO_COMPAT_FEATURE(jsb,mask) \
975 ((jsb)->header.blocktype >= to_be32(2) && \
976 ((jsb)->feature_ro_compat & to_be32((mask))))
977 #define JBD_HAS_INCOMPAT_FEATURE(jsb,mask) \
978 ((jsb)->header.blocktype >= to_be32(2) && \
979 ((jsb)->feature_incompat & to_be32((mask))))
981 #define JBD_FEATURE_COMPAT_CHECKSUM 0x00000001
983 #define JBD_FEATURE_INCOMPAT_REVOKE 0x00000001
984 #define JBD_FEATURE_INCOMPAT_64BIT 0x00000002
985 #define JBD_FEATURE_INCOMPAT_ASYNC_COMMIT 0x00000004
986 #define JBD_FEATURE_INCOMPAT_CSUM_V2 0x00000008
987 #define JBD_FEATURE_INCOMPAT_CSUM_V3 0x00000010
989 /* Features known to this kernel version: */
990 #define JBD_KNOWN_COMPAT_FEATURES 0
991 #define JBD_KNOWN_ROCOMPAT_FEATURES 0
992 #define JBD_KNOWN_INCOMPAT_FEATURES (JBD_FEATURE_INCOMPAT_REVOKE|\
993 JBD_FEATURE_INCOMPAT_ASYNC_COMMIT|\
994 JBD_FEATURE_INCOMPAT_64BIT|\
995 JBD_FEATURE_INCOMPAT_CSUM_V2|\
996 JBD_FEATURE_INCOMPAT_CSUM_V3)
998 /*****************************************************************************/
1000 #define EXT4_CRC32_INIT (0xFFFFFFFFUL)
1002 /*****************************************************************************/
1009 #if CONFIG_USE_USER_MALLOC
1011 #define ext4_malloc ext4_user_malloc
1012 #define ext4_calloc ext4_user_calloc
1013 #define ext4_realloc ext4_user_realloc
1014 #define ext4_free ext4_user_free
1018 #define ext4_malloc malloc
1019 #define ext4_calloc calloc
1020 #define ext4_realloc realloc
1021 #define ext4_free free
1026 #endif /* EXT4_TYPES_H_ */