Lines Matching +full:multi +full:- +full:cluster
1 .. SPDX-License-Identifier: GPL-2.0
4 -----------
21 .. list-table::
23 :header-rows: 1
25 * - Offset
26 - Size
27 - Name
28 - Description
29 * - 0x0
30 - __le32
31 - s_inodes_count
32 - Total inode count.
33 * - 0x4
34 - __le32
35 - s_blocks_count_lo
36 - Total block count.
37 * - 0x8
38 - __le32
39 - s_r_blocks_count_lo
40 - This number of blocks can only be allocated by the super-user.
41 * - 0xC
42 - __le32
43 - s_free_blocks_count_lo
44 - Free block count.
45 * - 0x10
46 - __le32
47 - s_free_inodes_count
48 - Free inode count.
49 * - 0x14
50 - __le32
51 - s_first_data_block
52 - First data block. This must be at least 1 for 1k-block filesystems and
54 * - 0x18
55 - __le32
56 - s_log_block_size
57 - Block size is 2 ^ (10 + s_log_block_size).
58 * - 0x1C
59 - __le32
60 - s_log_cluster_size
61 - Cluster size is 2 ^ (10 + s_log_cluster_size) blocks if bigalloc is
63 * - 0x20
64 - __le32
65 - s_blocks_per_group
66 - Blocks per group.
67 * - 0x24
68 - __le32
69 - s_clusters_per_group
70 - Clusters per group, if bigalloc is enabled. Otherwise
72 * - 0x28
73 - __le32
74 - s_inodes_per_group
75 - Inodes per group.
76 * - 0x2C
77 - __le32
78 - s_mtime
79 - Mount time, in seconds since the epoch.
80 * - 0x30
81 - __le32
82 - s_wtime
83 - Write time, in seconds since the epoch.
84 * - 0x34
85 - __le16
86 - s_mnt_count
87 - Number of mounts since the last fsck.
88 * - 0x36
89 - __le16
90 - s_max_mnt_count
91 - Number of mounts beyond which a fsck is needed.
92 * - 0x38
93 - __le16
94 - s_magic
95 - Magic signature, 0xEF53
96 * - 0x3A
97 - __le16
98 - s_state
99 - File system state. See super_state_ for more info.
100 * - 0x3C
101 - __le16
102 - s_errors
103 - Behaviour when detecting errors. See super_errors_ for more info.
104 * - 0x3E
105 - __le16
106 - s_minor_rev_level
107 - Minor revision level.
108 * - 0x40
109 - __le32
110 - s_lastcheck
111 - Time of last check, in seconds since the epoch.
112 * - 0x44
113 - __le32
114 - s_checkinterval
115 - Maximum time between checks, in seconds.
116 * - 0x48
117 - __le32
118 - s_creator_os
119 - Creator OS. See the table super_creator_ for more info.
120 * - 0x4C
121 - __le32
122 - s_rev_level
123 - Revision level. See the table super_revision_ for more info.
124 * - 0x50
125 - __le16
126 - s_def_resuid
127 - Default uid for reserved blocks.
128 * - 0x52
129 - __le16
130 - s_def_resgid
131 - Default gid for reserved blocks.
132 * -
133 -
134 -
135 - These fields are for EXT4_DYNAMIC_REV superblocks only.
145 * - 0x54
146 - __le32
147 - s_first_ino
148 - First non-reserved inode.
149 * - 0x58
150 - __le16
151 - s_inode_size
152 - Size of inode structure, in bytes.
153 * - 0x5A
154 - __le16
155 - s_block_group_nr
156 - Block group # of this superblock.
157 * - 0x5C
158 - __le32
159 - s_feature_compat
160 - Compatible feature set flags. Kernel can still read/write this fs even
163 * - 0x60
164 - __le32
165 - s_feature_incompat
166 - Incompatible feature set. If the kernel or fsck doesn't understand one
169 * - 0x64
170 - __le32
171 - s_feature_ro_compat
172 - Readonly-compatible feature set. If the kernel doesn't understand one of
173 these bits, it can still mount read-only. See the super_rocompat_ table
175 * - 0x68
176 - __u8
177 - s_uuid[16]
178 - 128-bit UUID for volume.
179 * - 0x78
180 - char
181 - s_volume_name[16]
182 - Volume label.
183 * - 0x88
184 - char
185 - s_last_mounted[64]
186 - Directory where filesystem was last mounted.
187 * - 0xC8
188 - __le32
189 - s_algorithm_usage_bitmap
190 - For compression (Not used in e2fsprogs/Linux)
191 * -
192 -
193 -
194 - Performance hints. Directory preallocation should only happen if the
196 * - 0xCC
197 - __u8
198 - s_prealloc_blocks
199 - #. of blocks to try to preallocate for ... files? (Not used in
201 * - 0xCD
202 - __u8
203 - s_prealloc_dir_blocks
204 - #. of blocks to preallocate for directories. (Not used in
206 * - 0xCE
207 - __le16
208 - s_reserved_gdt_blocks
209 - Number of reserved GDT entries for future filesystem expansion.
210 * -
211 -
212 -
213 - Journalling support is valid only if EXT4_FEATURE_COMPAT_HAS_JOURNAL is
215 * - 0xD0
216 - __u8
217 - s_journal_uuid[16]
218 - UUID of journal superblock
219 * - 0xE0
220 - __le32
221 - s_journal_inum
222 - inode number of journal file.
223 * - 0xE4
224 - __le32
225 - s_journal_dev
226 - Device number of journal file, if the external journal feature flag is
228 * - 0xE8
229 - __le32
230 - s_last_orphan
231 - Start of list of orphaned inodes to delete.
232 * - 0xEC
233 - __le32
234 - s_hash_seed[4]
235 - HTREE hash seed.
236 * - 0xFC
237 - __u8
238 - s_def_hash_version
239 - Default hash algorithm to use for directory hashes. See super_def_hash_
241 * - 0xFD
242 - __u8
243 - s_jnl_backup_type
244 - If this value is 0 or EXT3_JNL_BACKUP_BLOCKS (1), then the
247 * - 0xFE
248 - __le16
249 - s_desc_size
250 - Size of group descriptors, in bytes, if the 64bit incompat feature flag
252 * - 0x100
253 - __le32
254 - s_default_mount_opts
255 - Default mount options. See the super_mountopts_ table for more info.
256 * - 0x104
257 - __le32
258 - s_first_meta_bg
259 - First metablock block group, if the meta_bg feature is enabled.
260 * - 0x108
261 - __le32
262 - s_mkfs_time
263 - When the filesystem was created, in seconds since the epoch.
264 * - 0x10C
265 - __le32
266 - s_jnl_blocks[17]
267 - Backup copy of the journal inode's ``i_block[]`` array in the first 15
270 * -
271 -
272 -
273 - 64bit support is valid only if EXT4_FEATURE_COMPAT_64BIT is set.
274 * - 0x150
275 - __le32
276 - s_blocks_count_hi
277 - High 32-bits of the block count.
278 * - 0x154
279 - __le32
280 - s_r_blocks_count_hi
281 - High 32-bits of the reserved block count.
282 * - 0x158
283 - __le32
284 - s_free_blocks_count_hi
285 - High 32-bits of the free block count.
286 * - 0x15C
287 - __le16
288 - s_min_extra_isize
289 - All inodes have at least # bytes.
290 * - 0x15E
291 - __le16
292 - s_want_extra_isize
293 - New inodes should reserve # bytes.
294 * - 0x160
295 - __le32
296 - s_flags
297 - Miscellaneous flags. See the super_flags_ table for more info.
298 * - 0x164
299 - __le16
300 - s_raid_stride
301 - RAID stride. This is the number of logical blocks read from or written
304 * - 0x166
305 - __le16
306 - s_mmp_interval
307 - #. seconds to wait in multi-mount prevention (MMP) checking. In theory,
311 * - 0x168
312 - __le64
313 - s_mmp_block
314 - Block # for multi-mount protection data.
315 * - 0x170
316 - __le32
317 - s_raid_stripe_width
318 - RAID stripe width. This is the number of logical blocks read from or
320 by the block allocator to try to reduce the number of read-modify-write
322 * - 0x174
323 - __u8
324 - s_log_groups_per_flex
325 - Size of a flexible block group is 2 ^ ``s_log_groups_per_flex``.
326 * - 0x175
327 - __u8
328 - s_checksum_type
329 - Metadata checksum algorithm type. The only valid value is 1 (crc32c).
330 * - 0x176
331 - __le16
332 - s_reserved_pad
333 -
334 * - 0x178
335 - __le64
336 - s_kbytes_written
337 - Number of KiB written to this filesystem over its lifetime.
338 * - 0x180
339 - __le32
340 - s_snapshot_inum
341 - inode number of active snapshot. (Not used in e2fsprogs/Linux.)
342 * - 0x184
343 - __le32
344 - s_snapshot_id
345 - Sequential ID of active snapshot. (Not used in e2fsprogs/Linux.)
346 * - 0x188
347 - __le64
348 - s_snapshot_r_blocks_count
349 - Number of blocks reserved for active snapshot's future use. (Not used in
351 * - 0x190
352 - __le32
353 - s_snapshot_list
354 - inode number of the head of the on-disk snapshot list. (Not used in
356 * - 0x194
357 - __le32
358 - s_error_count
359 - Number of errors seen.
360 * - 0x198
361 - __le32
362 - s_first_error_time
363 - First time an error happened, in seconds since the epoch.
364 * - 0x19C
365 - __le32
366 - s_first_error_ino
367 - inode involved in first error.
368 * - 0x1A0
369 - __le64
370 - s_first_error_block
371 - Number of block involved of first error.
372 * - 0x1A8
373 - __u8
374 - s_first_error_func[32]
375 - Name of function where the error happened.
376 * - 0x1C8
377 - __le32
378 - s_first_error_line
379 - Line number where error happened.
380 * - 0x1CC
381 - __le32
382 - s_last_error_time
383 - Time of most recent error, in seconds since the epoch.
384 * - 0x1D0
385 - __le32
386 - s_last_error_ino
387 - inode involved in most recent error.
388 * - 0x1D4
389 - __le32
390 - s_last_error_line
391 - Line number where most recent error happened.
392 * - 0x1D8
393 - __le64
394 - s_last_error_block
395 - Number of block involved in most recent error.
396 * - 0x1E0
397 - __u8
398 - s_last_error_func[32]
399 - Name of function where the most recent error happened.
400 * - 0x200
401 - __u8
402 - s_mount_opts[64]
403 - ASCIIZ string of mount options.
404 * - 0x240
405 - __le32
406 - s_usr_quota_inum
407 - Inode number of user `quota <quota>`__ file.
408 * - 0x244
409 - __le32
410 - s_grp_quota_inum
411 - Inode number of group `quota <quota>`__ file.
412 * - 0x248
413 - __le32
414 - s_overhead_blocks
415 - Overhead blocks/clusters in fs. (Huh? This field is always zero, which
417 * - 0x24C
418 - __le32
419 - s_backup_bgs[2]
420 - Block groups containing superblock backups (if sparse_super2)
421 * - 0x254
422 - __u8
423 - s_encrypt_algos[4]
424 - Encryption algorithms in use. There can be up to four algorithms in use
427 * - 0x258
428 - __u8
429 - s_encrypt_pw_salt[16]
430 - Salt for the string2key algorithm for encryption.
431 * - 0x268
432 - __le32
433 - s_lpf_ino
434 - Inode number of lost+found
435 * - 0x26C
436 - __le32
437 - s_prj_quota_inum
438 - Inode that tracks project quotas.
439 * - 0x270
440 - __le32
441 - s_checksum_seed
442 - Checksum seed used for metadata_csum calculations. This value is
444 * - 0x274
445 - __u8
446 - s_wtime_hi
447 - Upper 8 bits of the s_wtime field.
448 * - 0x275
449 - __u8
450 - s_mtime_hi
451 - Upper 8 bits of the s_mtime field.
452 * - 0x276
453 - __u8
454 - s_mkfs_time_hi
455 - Upper 8 bits of the s_mkfs_time field.
456 * - 0x277
457 - __u8
458 - s_lastcheck_hi
459 - Upper 8 bits of the s_lastcheck field.
460 * - 0x278
461 - __u8
462 - s_first_error_time_hi
463 - Upper 8 bits of the s_first_error_time field.
464 * - 0x279
465 - __u8
466 - s_last_error_time_hi
467 - Upper 8 bits of the s_last_error_time field.
468 * - 0x27A
469 - __u8
470 - s_pad[2]
471 - Zero padding.
472 * - 0x27C
473 - __le16
474 - s_encoding
475 - Filename charset encoding.
476 * - 0x27E
477 - __le16
478 - s_encoding_flags
479 - Filename charset encoding flags.
480 * - 0x280
481 - __le32
482 - s_orphan_file_inum
483 - Orphan file inode number.
484 * - 0x284
485 - __le32
486 - s_reserved[94]
487 - Padding to the end of the block.
488 * - 0x3FC
489 - __le32
490 - s_checksum
491 - Superblock checksum.
497 .. list-table::
499 :header-rows: 1
501 * - Value
502 - Description
503 * - 0x0001
504 - Cleanly umounted
505 * - 0x0002
506 - Errors detected
507 * - 0x0004
508 - Orphans being recovered
514 .. list-table::
516 :header-rows: 1
518 * - Value
519 - Description
520 * - 1
521 - Continue
522 * - 2
523 - Remount read-only
524 * - 3
525 - Panic
531 .. list-table::
533 :header-rows: 1
535 * - Value
536 - Description
537 * - 0
538 - Linux
539 * - 1
540 - Hurd
541 * - 2
542 - Masix
543 * - 3
544 - FreeBSD
545 * - 4
546 - Lites
552 .. list-table::
554 :header-rows: 1
556 * - Value
557 - Description
558 * - 0
559 - Original format
560 * - 1
561 - v2 format w/ dynamic inode sizes
570 .. list-table::
572 :header-rows: 1
574 * - Value
575 - Description
576 * - 0x1
577 - Directory preallocation (COMPAT_DIR_PREALLOC).
578 * - 0x2
579 - “imagic inodes”. Not clear from the code what this does
581 * - 0x4
582 - Has a journal (COMPAT_HAS_JOURNAL).
583 * - 0x8
584 - Supports extended attributes (COMPAT_EXT_ATTR).
585 * - 0x10
586 - Has reserved GDT blocks for filesystem expansion
588 * - 0x20
589 - Has directory indices (COMPAT_DIR_INDEX).
590 * - 0x40
591 - “Lazy BG”. Not in Linux kernel, seems to have been for uninitialized
593 * - 0x80
594 - “Exclude inode”. Not used. (COMPAT_EXCLUDE_INODE).
595 * - 0x100
596 - “Exclude bitmap”. Seems to be used to indicate the presence of
597 snapshot-related exclude bitmaps? Not defined in kernel or used in
599 * - 0x200
600 - Sparse Super Block, v2. If this flag is set, the SB field s_backup_bgs
603 * - 0x400
604 - Fast commits supported. Although fast commits blocks are
610 * - 0x1000
611 - Orphan file allocated. This is the special file for more efficient
621 .. list-table::
623 :header-rows: 1
625 * - Value
626 - Description
627 * - 0x1
628 - Compression (INCOMPAT_COMPRESSION).
629 * - 0x2
630 - Directory entries record the file type. See ext4_dir_entry_2 below
632 * - 0x4
633 - Filesystem needs recovery (INCOMPAT_RECOVER).
634 * - 0x8
635 - Filesystem has a separate journal device (INCOMPAT_JOURNAL_DEV).
636 * - 0x10
637 - Meta block groups. See the earlier discussion of this feature
639 * - 0x40
640 - Files in this filesystem use extents (INCOMPAT_EXTENTS).
641 * - 0x80
642 - Enable a filesystem size of 2^64 blocks (INCOMPAT_64BIT).
643 * - 0x100
644 - Multiple mount protection (INCOMPAT_MMP).
645 * - 0x200
646 - Flexible block groups. See the earlier discussion of this feature
648 * - 0x400
649 - Inodes can be used to store large extended attribute values
651 * - 0x1000
652 - Data in directory entry (INCOMPAT_DIRDATA). (Not implemented?)
653 * - 0x2000
654 - Metadata checksum seed is stored in the superblock. This feature enables
658 * - 0x4000
659 - Large directory >2GB or 3-level htree (INCOMPAT_LARGEDIR). Prior to
663 * - 0x8000
664 - Data in inode (INCOMPAT_INLINE_DATA).
665 * - 0x10000
666 - Encrypted inodes are present on the filesystem. (INCOMPAT_ENCRYPT).
670 The superblock read-only compatible features field is a combination of any of
673 .. list-table::
675 :header-rows: 1
677 * - Value
678 - Description
679 * - 0x1
680 - Sparse superblocks. See the earlier discussion of this feature
682 * - 0x2
683 - This filesystem has been used to store a file greater than 2GiB
685 * - 0x4
686 - Not used in kernel or e2fsprogs (RO_COMPAT_BTREE_DIR).
687 * - 0x8
688 - This filesystem has files whose sizes are represented in units of
689 logical blocks, not 512-byte sectors. This implies a very large file
691 * - 0x10
692 - Group descriptors have checksums. In addition to detecting corruption,
695 * - 0x20
696 - Indicates that the old ext3 32,000 subdirectory limit no longer applies
699 * - 0x40
700 - Indicates that large inodes exist on this filesystem
702 * - 0x80
703 - This filesystem has a snapshot (RO_COMPAT_HAS_SNAPSHOT).
704 * - 0x100
705 - `Quota <Quota>`__ (RO_COMPAT_QUOTA).
706 * - 0x200
707 - This filesystem supports “bigalloc”, which means that file extents are
710 * - 0x400
711 - This filesystem supports metadata checksumming.
714 * - 0x800
715 - Filesystem supports replicas. This feature is neither in the kernel nor
717 * - 0x1000
718 - Read-only filesystem image; the kernel will not mount this image
719 read-write and most tools will refuse to write to the image.
721 * - 0x2000
722 - Filesystem tracks project quotas. (RO_COMPAT_PROJECT)
723 * - 0x8000
724 - Verity inodes may be present on the filesystem. (RO_COMPAT_VERITY)
725 * - 0x10000
726 - Indicates orphan file may have valid orphan entries and thus we need
734 .. list-table::
736 :header-rows: 1
738 * - Value
739 - Description
740 * - 0x0
741 - Legacy.
742 * - 0x1
743 - Half MD4.
744 * - 0x2
745 - Tea.
746 * - 0x3
747 - Legacy, unsigned.
748 * - 0x4
749 - Half MD4, unsigned.
750 * - 0x5
751 - Tea, unsigned.
757 .. list-table::
759 :header-rows: 1
761 * - Value
762 - Description
763 * - 0x0001
764 - Print debugging info upon (re)mount. (EXT4_DEFM_DEBUG)
765 * - 0x0002
766 - New files take the gid of the containing directory (instead of the fsgid
768 * - 0x0004
769 - Support userspace-provided extended attributes. (EXT4_DEFM_XATTR_USER)
770 * - 0x0008
771 - Support POSIX access control lists (ACLs). (EXT4_DEFM_ACL)
772 * - 0x0010
773 - Do not support 32-bit UIDs. (EXT4_DEFM_UID16)
774 * - 0x0020
775 - All data and metadata are committed to the journal.
777 * - 0x0040
778 - All data are flushed to the disk before metadata are committed to the
780 * - 0x0060
781 - Data ordering is not preserved; data may be written after the metadata
783 * - 0x0100
784 - Disable write flushes. (EXT4_DEFM_NOBARRIER)
785 * - 0x0200
786 - Track which blocks in a filesystem are metadata and therefore should not
789 * - 0x0400
790 - Enable DISCARD support, where the storage device is told about blocks
792 * - 0x0800
793 - Disable delayed allocation. (EXT4_DEFM_NODELALLOC)
799 .. list-table::
801 :header-rows: 1
803 * - Value
804 - Description
805 * - 0x0001
806 - Signed directory hash in use.
807 * - 0x0002
808 - Unsigned directory hash in use.
809 * - 0x0004
810 - To test development code.
816 .. list-table::
818 :header-rows: 1
820 * - Value
821 - Description
822 * - 0
823 - Invalid algorithm (ENCRYPTION_MODE_INVALID).
824 * - 1
825 - 256-bit AES in XTS mode (ENCRYPTION_MODE_AES_256_XTS).
826 * - 2
827 - 256-bit AES in GCM mode (ENCRYPTION_MODE_AES_256_GCM).
828 * - 3
829 - 256-bit AES in CBC mode (ENCRYPTION_MODE_AES_256_CBC).