Bsphinx.addnodesdocument)}( rawsourcechildren]( translations LanguagesNode)}(hhh](h pending_xref)}(hhh]docutils.nodesTextChinese (Simplified)}parenthsba attributes}(ids]classes]names]dupnames]backrefs] refdomainstdreftypedoc reftarget,/translations/zh_CN/filesystems/ext4/globalsmodnameN classnameN refexplicitutagnamehhh ubh)}(hhh]hChinese (Traditional)}hh2sbah}(h]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget,/translations/zh_TW/filesystems/ext4/globalsmodnameN classnameN refexplicituh1hhh ubh)}(hhh]hItalian}hhFsbah}(h]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget,/translations/it_IT/filesystems/ext4/globalsmodnameN classnameN refexplicituh1hhh ubh)}(hhh]hJapanese}hhZsbah}(h]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget,/translations/ja_JP/filesystems/ext4/globalsmodnameN classnameN refexplicituh1hhh ubh)}(hhh]hKorean}hhnsbah}(h]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget,/translations/ko_KR/filesystems/ext4/globalsmodnameN classnameN refexplicituh1hhh ubh)}(hhh]hSpanish}hhsbah}(h]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget,/translations/sp_SP/filesystems/ext4/globalsmodnameN classnameN refexplicituh1hhh ubeh}(h]h ]h"]h$]h&]current_languageEnglishuh1h hh _documenthsourceNlineNubhcomment)}(h SPDX-License-Identifier: GPL-2.0h]h SPDX-License-Identifier: GPL-2.0}hhsbah}(h]h ]h"]h$]h&] xml:spacepreserveuh1hhhhhhF/var/lib/git/docbuild/linux/Documentation/filesystems/ext4/globals.rsthKubhsection)}(hhh](htitle)}(hGlobal Structuresh]hGlobal Structures}(hhhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhhhhhKubh paragraph)}(hoThe filesystem is sharded into a number of block groups, each of which have static metadata at fixed locations.h]hoThe filesystem is sharded into a number of block groups, each of which have static metadata at fixed locations.}(hhhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhhhhubh)}(h SPDX-License-Identifier: GPL-2.0h]h SPDX-License-Identifier: GPL-2.0}hhsbah}(h]h ]h"]h$]h&]hhuh1hhhhhh(Documentation/filesystems/ext4/super.rsthKubh)}(hhh](h)}(h Super Blockh]h Super Block}(hhhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhhhhhKubh)}(hThe superblock records various information about the enclosing filesystem, such as block counts, inode counts, supported features, maintenance information, and more.h]hThe superblock records various information about the enclosing filesystem, such as block counts, inode counts, supported features, maintenance information, and more.}(hhhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhhhhubh)}(hIf the sparse_super feature flag is set, redundant copies of the superblock and group descriptors are kept only in the groups whose group number is either 0 or a power of 3, 5, or 7. If the flag is not set, redundant copies are kept in all groups.h]hIf the sparse_super feature flag is set, redundant copies of the superblock and group descriptors are kept only in the groups whose group number is either 0 or a power of 3, 5, or 7. If the flag is not set, redundant copies are kept in all groups.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK hhhhubh)}(hcThe superblock checksum is calculated against the superblock structure, which includes the FS UUID.h]hcThe superblock checksum is calculated against the superblock structure, which includes the FS UUID.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhhhhubh)}(hJThe ext4 superblock is laid out as follows in ``struct ext4_super_block``:h](h.The ext4 superblock is laid out as follows in }(hj#hhhNhNubhliteral)}(h``struct ext4_super_block``h]hstruct ext4_super_block}(hj-hhhNhNubah}(h]h ]h"]h$]h&]uh1j+hj#ubh:}(hj#hhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhKhhhhubhtable)}(hhh]htgroup)}(hhh](hcolspec)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jOhjLubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhjLubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhjLubjP)}(hhh]h}(h]h ]h"]h$]h&]jZK(uh1jOhjLubhthead)}(hhh]hrow)}(hhh](hentry)}(hhh]h)}(hOffseth]hOffset}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhj}ubj)}(hhh]h)}(hSizeh]hSize}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhj}ubj)}(hhh]h)}(hNameh]hName}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhj}ubj)}(hhh]h)}(h Descriptionh]h Description}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhj}ubeh}(h]h ]h"]h$]h&]uh1j{hjxubah}(h]h ]h"]h$]h&]uh1jvhjLubhtbody)}(hhh](j|)}(hhh](j)}(hhh]h)}(h0x0h]h0x0}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h__le32h]h__le32}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hs_inodes_counth]hs_inodes_count}(hj#hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hTotal inode count.h]hTotal inode count.}(hj:hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK hj7ubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x4h]h0x4}(hjZhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK!hjWubah}(h]h ]h"]h$]h&]uh1jhjTubj)}(hhh]h)}(h__le32h]h__le32}(hjqhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK"hjnubah}(h]h ]h"]h$]h&]uh1jhjTubj)}(hhh]h)}(hs_blocks_count_loh]hs_blocks_count_lo}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK#hjubah}(h]h ]h"]h$]h&]uh1jhjTubj)}(hhh]h)}(hTotal block count.h]hTotal block count.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK$hjubah}(h]h ]h"]h$]h&]uh1jhjTubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x8h]h0x8}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK%hjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h__le32h]h__le32}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK&hjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hs_r_blocks_count_loh]hs_r_blocks_count_lo}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK'hjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h>This number of blocks can only be allocated by the super-user.h]h>This number of blocks can only be allocated by the super-user.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK(hjubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0xCh]h0xC}(hj$hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK)hj!ubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h__le32h]h__le32}(hj;hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK*hj8ubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hs_free_blocks_count_loh]hs_free_blocks_count_lo}(hjRhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK+hjOubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hFree block count.h]hFree block count.}(hjihhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK,hjfubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x10h]h0x10}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK-hjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h__le32h]h__le32}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK.hjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hs_free_inodes_counth]hs_free_inodes_count}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK/hjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hFree inode count.h]hFree inode count.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK0hjubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x14h]h0x14}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK1hjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h__le32h]h__le32}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK2hjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hs_first_data_blockh]hs_first_data_block}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK3hjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hpFirst data block. This must be at least 1 for 1k-block filesystems and is typically 0 for all other block sizes.h]hpFirst data block. This must be at least 1 for 1k-block filesystems and is typically 0 for all other block sizes.}(hj3hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK4hj0ubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x18h]h0x18}(hjShhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK6hjPubah}(h]h ]h"]h$]h&]uh1jhjMubj)}(hhh]h)}(h__le32h]h__le32}(hjjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK7hjgubah}(h]h ]h"]h$]h&]uh1jhjMubj)}(hhh]h)}(hs_log_block_sizeh]hs_log_block_size}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK8hj~ubah}(h]h ]h"]h$]h&]uh1jhjMubj)}(hhh]h)}(h*Block size is 2 ^ (10 + s_log_block_size).h]h*Block size is 2 ^ (10 + s_log_block_size).}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK9hjubah}(h]h ]h"]h$]h&]uh1jhjMubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x1Ch]h0x1C}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK:hjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h__le32h]h__le32}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK;hjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hs_log_cluster_sizeh]hs_log_cluster_size}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKubah}(h]h ]h"]h$]h&]uh1jhj$ubj)}(hhh]h)}(hs_feature_incompath]hs_feature_incompat}(hjXhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjUubah}(h]h ]h"]h$]h&]uh1jhj$ubj)}(hhh]h)}(hIncompatible feature set. If the kernel or fsck doesn't understand one of these bits, it should stop. See the super_incompat_ table for more info.h](hpIncompatible feature set. If the kernel or fsck doesn’t understand one of these bits, it should stop. See the }(hjohhhNhNubj)}(hsuper_incompat_h]hsuper_incompat}(hjwhhhNhNubah}(h]h ]h"]h$]h&]namesuper_incompatjsuper-incompatuh1jhjojKubh table for more info.}(hjohhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhKhjlubah}(h]h ]h"]h$]h&]uh1jhj$ubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x64h]h0x64}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h__le32h]h__le32}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hs_feature_ro_compath]hs_feature_ro_compat}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hReadonly-compatible feature set. If the kernel doesn't understand one of these bits, it can still mount read-only. See the super_rocompat_ table for more info.h](h}Readonly-compatible feature set. If the kernel doesn’t understand one of these bits, it can still mount read-only. See the }(hjhhhNhNubj)}(hsuper_rocompat_h]hsuper_rocompat}(hjhhhNhNubah}(h]h ]h"]h$]h&]namesuper_rocompatjsuper-rocompatuh1jhjjKubh table for more info.}(hjhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x68h]h0x68}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h__u8h]h__u8}(hj5hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj2ubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h s_uuid[16]h]h s_uuid[16]}(hjLhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjIubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h128-bit UUID for volume.h]h128-bit UUID for volume.}(hjchhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj`ubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x78h]h0x78}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhj}ubj)}(hhh]h)}(hcharh]hchar}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhj}ubj)}(hhh]h)}(hs_volume_name[16]h]hs_volume_name[16]}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhj}ubj)}(hhh]h)}(h Volume label.h]h Volume label.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhj}ubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x88h]h0x88}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hcharh]hchar}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hs_last_mounted[64]h]hs_last_mounted[64]}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h,Directory where filesystem was last mounted.h]h,Directory where filesystem was last mounted.}(hj-hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj*ubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0xC8h]h0xC8}(hjMhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjJubah}(h]h ]h"]h$]h&]uh1jhjGubj)}(hhh]h)}(h__le32h]h__le32}(hjdhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjaubah}(h]h ]h"]h$]h&]uh1jhjGubj)}(hhh]h)}(hs_algorithm_usage_bitmaph]hs_algorithm_usage_bitmap}(hj{hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjxubah}(h]h ]h"]h$]h&]uh1jhjGubj)}(hhh]h)}(h-For compression (Not used in e2fsprogs/Linux)h]h-For compression (Not used in e2fsprogs/Linux)}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjGubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hrPerformance hints. Directory preallocation should only happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.h]hrPerformance hints. Directory preallocation should only happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0xCCh]h0xCC}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h__u8h]h__u8}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hs_prealloc_blocksh]hs_prealloc_blocks}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hO#. of blocks to try to preallocate for ... files? (Not used in e2fsprogs/Linux)h]hO#. of blocks to try to preallocate for ... files? (Not used in e2fsprogs/Linux)}(hj2hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj/ubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0xCDh]h0xCD}(hjRhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjOubah}(h]h ]h"]h$]h&]uh1jhjLubj)}(hhh]h)}(h__u8h]h__u8}(hjihhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjfubah}(h]h ]h"]h$]h&]uh1jhjLubj)}(hhh]h)}(hs_prealloc_dir_blocksh]hs_prealloc_dir_blocks}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj}ubah}(h]h ]h"]h$]h&]uh1jhjLubj)}(hhh]h)}(hJ#. of blocks to preallocate for directories. (Not used in e2fsprogs/Linux)h]hJ#. of blocks to preallocate for directories. (Not used in e2fsprogs/Linux)}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjLubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0xCEh]h0xCE}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h__le16h]h__le16}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hs_reserved_gdt_blocksh]hs_reserved_gdt_blocks}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h?Number of reserved GDT entries for future filesystem expansion.h]h?Number of reserved GDT entries for future filesystem expansion.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hLJournalling support is valid only if EXT4_FEATURE_COMPAT_HAS_JOURNAL is set.h]hLJournalling support is valid only if EXT4_FEATURE_COMPAT_HAS_JOURNAL is set.}(hj7hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj4ubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0xD0h]h0xD0}(hjWhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjTubah}(h]h ]h"]h$]h&]uh1jhjQubj)}(hhh]h)}(h__u8h]h__u8}(hjnhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjkubah}(h]h ]h"]h$]h&]uh1jhjQubj)}(hhh]h)}(hs_journal_uuid[16]h]hs_journal_uuid[16]}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjQubj)}(hhh]h)}(hUUID of journal superblockh]hUUID of journal superblock}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjQubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0xE0h]h0xE0}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h__le32h]h__le32}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hs_journal_inumh]hs_journal_inum}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hinode number of journal file.h]hinode number of journal file.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0xE4h]h0xE4}(hj!hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h__le32h]h__le32}(hj8hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj5ubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h s_journal_devh]h s_journal_dev}(hjOhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjLubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hKDevice number of journal file, if the external journal feature flag is set.h]hKDevice number of journal file, if the external journal feature flag is set.}(hjfhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjcubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0xE8h]h0xE8}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h__le32h]h__le32}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h s_last_orphanh]h s_last_orphan}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h+Start of list of orphaned inodes to delete.h]h+Start of list of orphaned inodes to delete.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0xECh]h0xEC}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h__le32h]h__le32}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hs_hash_seed[4]h]hs_hash_seed[4]}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hHTREE hash seed.h]hHTREE hash seed.}(hj0hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj-ubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0xFCh]h0xFC}(hjPhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjMubah}(h]h ]h"]h$]h&]uh1jhjJubj)}(hhh]h)}(h__u8h]h__u8}(hjghhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjdubah}(h]h ]h"]h$]h&]uh1jhjJubj)}(hhh]h)}(hs_def_hash_versionh]hs_def_hash_version}(hj~hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj{ubah}(h]h ]h"]h$]h&]uh1jhjJubj)}(hhh]h)}(hVDefault hash algorithm to use for directory hashes. See super_def_hash_ for more info.h](h8Default hash algorithm to use for directory hashes. See }(hjhhhNhNubj)}(hsuper_def_hash_h]hsuper_def_hash}(hjhhhNhNubah}(h]h ]h"]h$]h&]namesuper_def_hashjsuper-def-hashuh1jhjjKubh for more info.}(hjhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjJubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0xFDh]h0xFD}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h__u8h]h__u8}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hs_jnl_backup_typeh]hs_jnl_backup_type}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hIf this value is 0 or EXT3_JNL_BACKUP_BLOCKS (1), then the ``s_jnl_blocks`` field contains a duplicate copy of the inode's ``i_block[]`` array and ``i_size``.h](h;If this value is 0 or EXT3_JNL_BACKUP_BLOCKS (1), then the }(hjhhhNhNubj,)}(h``s_jnl_blocks``h]h s_jnl_blocks}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1j+hjubh2 field contains a duplicate copy of the inode’s }(hjhhhNhNubj,)}(h ``i_block[]``h]h i_block[]}(hj)hhhNhNubah}(h]h ]h"]h$]h&]uh1j+hjubh array and }(hjhhhNhNubj,)}(h ``i_size``h]hi_size}(hj;hhhNhNubah}(h]h ]h"]h$]h&]uh1j+hjubh.}(hjhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0xFEh]h0xFE}(hjehhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjbubah}(h]h ]h"]h$]h&]uh1jhj_ubj)}(hhh]h)}(h__le16h]h__le16}(hj|hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjyubah}(h]h ]h"]h$]h&]uh1jhj_ubj)}(hhh]h)}(h s_desc_sizeh]h s_desc_size}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhj_ubj)}(hhh]h)}(hOSize of group descriptors, in bytes, if the 64bit incompat feature flag is set.h]hOSize of group descriptors, in bytes, if the 64bit incompat feature flag is set.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhj_ubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x100h]h0x100}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h__le32h]h__le32}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hs_default_mount_optsh]hs_default_mount_opts}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hDDefault mount options. See the super_mountopts_ table for more info.h](hDefault mount options. See the }(hjhhhNhNubj)}(hsuper_mountopts_h]hsuper_mountopts}(hjhhhNhNubah}(h]h ]h"]h$]h&]namesuper_mountoptsjsuper-mountoptsuh1jhjjKubh table for more info.}(hjhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x104h]h0x104}(hjDhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjAubah}(h]h ]h"]h$]h&]uh1jhj>ubj)}(hhh]h)}(h__le32h]h__le32}(hj[hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjXubah}(h]h ]h"]h$]h&]uh1jhj>ubj)}(hhh]h)}(hs_first_meta_bgh]hs_first_meta_bg}(hjrhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjoubah}(h]h ]h"]h$]h&]uh1jhj>ubj)}(hhh]h)}(h?First metablock block group, if the meta_bg feature is enabled.h]h?First metablock block group, if the meta_bg feature is enabled.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjubah}(h]h ]h"]h$]h&]uh1jhj>ubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x108h]h0x108}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h__le32h]h__le32}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h s_mkfs_timeh]h s_mkfs_time}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hMiscellaneous flags. See the super_flags_ table for more info.h](hMiscellaneous flags. See the }(hjhhhNhNubj)}(h super_flags_h]h super_flags}(hjhhhNhNubah}(h]h ]h"]h$]h&]name super_flagsj super-flagsuh1jhjjKubh table for more info.}(hjhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhM)hjubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x164h]h0x164}(hj3hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM*hj0ubah}(h]h ]h"]h$]h&]uh1jhj-ubj)}(hhh]h)}(h__le16h]h__le16}(hjJhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM+hjGubah}(h]h ]h"]h$]h&]uh1jhj-ubj)}(hhh]h)}(h s_raid_strideh]h s_raid_stride}(hjahhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM,hj^ubah}(h]h ]h"]h$]h&]uh1jhj-ubj)}(hhh]h)}(hRAID stride. This is the number of logical blocks read from or written to the disk before moving to the next disk. This affects the placement of filesystem metadata, which will hopefully make RAID storage faster.h]hRAID stride. This is the number of logical blocks read from or written to the disk before moving to the next disk. This affects the placement of filesystem metadata, which will hopefully make RAID storage faster.}(hjxhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM-hjuubah}(h]h ]h"]h$]h&]uh1jhj-ubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x166h]h0x166}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM0hjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h__le16h]h__le16}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM1hjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hs_mmp_intervalh]hs_mmp_interval}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM2hjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h#. seconds to wait in multi-mount prevention (MMP) checking. In theory, MMP is a mechanism to record in the superblock which host and device have mounted the filesystem, in order to prevent multiple mounts. This feature does not seem to be implemented...h]h#. seconds to wait in multi-mount prevention (MMP) checking. In theory, MMP is a mechanism to record in the superblock which host and device have mounted the filesystem, in order to prevent multiple mounts. This feature does not seem to be implemented...}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM3hjubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x168h]h0x168}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM7hjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h__le64h]h__le64}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM8hjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h s_mmp_blockh]h s_mmp_block}(hj+hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM9hj(ubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h(Block # for multi-mount protection data.h]h(Block # for multi-mount protection data.}(hjBhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM:hj?ubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x170h]h0x170}(hjbhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM;hj_ubah}(h]h ]h"]h$]h&]uh1jhj\ubj)}(hhh]h)}(h__le32h]h__le32}(hjyhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM<hjvubah}(h]h ]h"]h$]h&]uh1jhj\ubj)}(hhh]h)}(hs_raid_stripe_widthh]hs_raid_stripe_width}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM=hjubah}(h]h ]h"]h$]h&]uh1jhj\ubj)}(hhh]h)}(hRAID stripe width. This is the number of logical blocks read from or written to the disk before coming back to the current disk. This is used by the block allocator to try to reduce the number of read-modify-write operations in a RAID5/6.h]hRAID stripe width. This is the number of logical blocks read from or written to the disk before coming back to the current disk. This is used by the block allocator to try to reduce the number of read-modify-write operations in a RAID5/6.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM>hjubah}(h]h ]h"]h$]h&]uh1jhj\ubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x174h]h0x174}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMBhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h__u8h]h__u8}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMChjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hs_log_groups_per_flexh]hs_log_groups_per_flex}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMDhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h@Size of a flexible block group is 2 ^ ``s_log_groups_per_flex``.h](h&Size of a flexible block group is 2 ^ }(hj hhhNhNubj,)}(h``s_log_groups_per_flex``h]hs_log_groups_per_flex}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1j+hj ubh.}(hj hhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhMEhj ubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x175h]h0x175}(hj>hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMFhj;ubah}(h]h ]h"]h$]h&]uh1jhj8ubj)}(hhh]h)}(h__u8h]h__u8}(hjUhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMGhjRubah}(h]h ]h"]h$]h&]uh1jhj8ubj)}(hhh]h)}(hs_checksum_typeh]hs_checksum_type}(hjlhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMHhjiubah}(h]h ]h"]h$]h&]uh1jhj8ubj)}(hhh]h)}(hEMetadata checksum algorithm type. The only valid value is 1 (crc32c).h]hEMetadata checksum algorithm type. The only valid value is 1 (crc32c).}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMIhjubah}(h]h ]h"]h$]h&]uh1jhj8ubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x176h]h0x176}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMJhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h\_\_u8h]h__u8}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hs\_encryption\_levelh]hs_encryption_level}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMLhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h Versioning level for encryption.h]h Versioning level for encryption.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMMhjubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x177h]h0x177}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMNhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h\_\_u8h]h__u8}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMOhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hs\_reserved\_padh]hs_reserved_pad}(hj6hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMPhj3ubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hPadding to next 32bits.h]hPadding to next 32bits.}(hjMhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMQhjJubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x178h]h0x178}(hjmhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMRhjjubah}(h]h ]h"]h$]h&]uh1jhjgubj)}(hhh]h)}(h__le64h]h__le64}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMShjubah}(h]h ]h"]h$]h&]uh1jhjgubj)}(hhh]h)}(hs_kbytes_writtenh]hs_kbytes_written}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMThjubah}(h]h ]h"]h$]h&]uh1jhjgubj)}(hhh]h)}(h;Number of KiB written to this filesystem over its lifetime.h]h;Number of KiB written to this filesystem over its lifetime.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMUhjubah}(h]h ]h"]h$]h&]uh1jhjgubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x180h]h0x180}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMVhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h__le32h]h__le32}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMWhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hs_snapshot_inumh]hs_snapshot_inum}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMXhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h?inode number of active snapshot. (Not used in e2fsprogs/Linux.)h]h?inode number of active snapshot. (Not used in e2fsprogs/Linux.)}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMYhjubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x184h]h0x184}(hj7hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMZhj4ubah}(h]h ]h"]h$]h&]uh1jhj1ubj)}(hhh]h)}(h__le32h]h__le32}(hjNhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM[hjKubah}(h]h ]h"]h$]h&]uh1jhj1ubj)}(hhh]h)}(h s_snapshot_idh]h s_snapshot_id}(hjehhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM\hjbubah}(h]h ]h"]h$]h&]uh1jhj1ubj)}(hhh]h)}(h@Sequential ID of active snapshot. (Not used in e2fsprogs/Linux.)h]h@Sequential ID of active snapshot. (Not used in e2fsprogs/Linux.)}(hj|hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM]hjyubah}(h]h ]h"]h$]h&]uh1jhj1ubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x188h]h0x188}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM^hjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h__le64h]h__le64}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM_hjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hs_snapshot_r_blocks_counth]hs_snapshot_r_blocks_count}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM`hjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hZNumber of blocks reserved for active snapshot's future use. (Not used in e2fsprogs/Linux.)h]h\Number of blocks reserved for active snapshot’s future use. (Not used in e2fsprogs/Linux.)}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMahjubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x190h]h0x190}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMchjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h__le32h]h__le32}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMdhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hs_snapshot_listh]hs_snapshot_list}(hj/hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMehj,ubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hUinode number of the head of the on-disk snapshot list. (Not used in e2fsprogs/Linux.)h]hUinode number of the head of the on-disk snapshot list. (Not used in e2fsprogs/Linux.)}(hjFhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMfhjCubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x194h]h0x194}(hjfhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhhjcubah}(h]h ]h"]h$]h&]uh1jhj`ubj)}(hhh]h)}(h__le32h]h__le32}(hj}hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMihjzubah}(h]h ]h"]h$]h&]uh1jhj`ubj)}(hhh]h)}(h s_error_counth]h s_error_count}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMjhjubah}(h]h ]h"]h$]h&]uh1jhj`ubj)}(hhh]h)}(hNumber of errors seen.h]hNumber of errors seen.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMkhjubah}(h]h ]h"]h$]h&]uh1jhj`ubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x198h]h0x198}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMlhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h__le32h]h__le32}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMmhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hs_first_error_timeh]hs_first_error_time}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMnhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h9First time an error happened, in seconds since the epoch.h]h9First time an error happened, in seconds since the epoch.}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMohj ubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x19Ch]h0x19C}(hj0 hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMphj- ubah}(h]h ]h"]h$]h&]uh1jhj* ubj)}(hhh]h)}(h__le32h]h__le32}(hjG hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMqhjD ubah}(h]h ]h"]h$]h&]uh1jhj* ubj)}(hhh]h)}(hs_first_error_inoh]hs_first_error_ino}(hj^ hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMrhj[ ubah}(h]h ]h"]h$]h&]uh1jhj* ubj)}(hhh]h)}(hinode involved in first error.h]hinode involved in first error.}(hju hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMshjr ubah}(h]h ]h"]h$]h&]uh1jhj* ubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x1A0h]h0x1A0}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMthj ubah}(h]h ]h"]h$]h&]uh1jhj ubj)}(hhh]h)}(h__le64h]h__le64}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMuhj ubah}(h]h ]h"]h$]h&]uh1jhj ubj)}(hhh]h)}(hs_first_error_blockh]hs_first_error_block}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMvhj ubah}(h]h ]h"]h$]h&]uh1jhj ubj)}(hhh]h)}(h(Number of block involved of first error.h]h(Number of block involved of first error.}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMwhj ubah}(h]h ]h"]h$]h&]uh1jhj ubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x1A8h]h0x1A8}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMxhj ubah}(h]h ]h"]h$]h&]uh1jhj ubj)}(hhh]h)}(h__u8h]h__u8}(hj!hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMyhj!ubah}(h]h ]h"]h$]h&]uh1jhj ubj)}(hhh]h)}(hs_first_error_func[32]h]hs_first_error_func[32]}(hj(!hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMzhj%!ubah}(h]h ]h"]h$]h&]uh1jhj ubj)}(hhh]h)}(h*Name of function where the error happened.h]h*Name of function where the error happened.}(hj?!hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM{hj`__ file.h](hInode number of user }(hjg$hhhNhNubj)}(h`quota `__h]hquota}(hjo$hhhNhNubah}(h]h ]h"]h$]h&]namequotarefuriquotauh1jhjg$ubh file.}(hjg$hhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhMhjd$ubah}(h]h ]h"]h$]h&]uh1jhj$ubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x244h]h0x244}(hj$hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj$ubah}(h]h ]h"]h$]h&]uh1jhj$ubj)}(hhh]h)}(h__le32h]h__le32}(hj$hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj$ubah}(h]h ]h"]h$]h&]uh1jhj$ubj)}(hhh]h)}(hs_grp_quota_inumh]hs_grp_quota_inum}(hj$hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj$ubah}(h]h ]h"]h$]h&]uh1jhj$ubj)}(hhh]h)}(h-Inode number of group `quota `__ file.h](hInode number of group }(hj$hhhNhNubj)}(h`quota `__h]hquota}(hj$hhhNhNubah}(h]h ]h"]h$]h&]namequotaj$quotauh1jhj$ubh file.}(hj$hhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhMhj$ubah}(h]h ]h"]h$]h&]uh1jhj$ubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x248h]h0x248}(hj%hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj%ubah}(h]h ]h"]h$]h&]uh1jhj%ubj)}(hhh]h)}(h__le32h]h__le32}(hj.%hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj+%ubah}(h]h ]h"]h$]h&]uh1jhj%ubj)}(hhh]h)}(hs_overhead_blocksh]hs_overhead_blocks}(hjE%hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjB%ubah}(h]h ]h"]h$]h&]uh1jhj%ubj)}(hhh]h)}(hxOverhead blocks/clusters in fs. (Huh? This field is always zero, which means that the kernel calculates it dynamically.)h]hxOverhead blocks/clusters in fs. (Huh? This field is always zero, which means that the kernel calculates it dynamically.)}(hj\%hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjY%ubah}(h]h ]h"]h$]h&]uh1jhj%ubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x24Ch]h0x24C}(hj|%hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjy%ubah}(h]h ]h"]h$]h&]uh1jhjv%ubj)}(hhh]h)}(h__le32h]h__le32}(hj%hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj%ubah}(h]h ]h"]h$]h&]uh1jhjv%ubj)}(hhh]h)}(hs_backup_bgs[2]h]hs_backup_bgs[2]}(hj%hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj%ubah}(h]h ]h"]h$]h&]uh1jhjv%ubj)}(hhh]h)}(h=Block groups containing superblock backups (if sparse_super2)h]h=Block groups containing superblock backups (if sparse_super2)}(hj%hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj%ubah}(h]h ]h"]h$]h&]uh1jhjv%ubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x254h]h0x254}(hj%hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj%ubah}(h]h ]h"]h$]h&]uh1jhj%ubj)}(hhh]h)}(h__u8h]h__u8}(hj%hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj%ubah}(h]h ]h"]h$]h&]uh1jhj%ubj)}(hhh]h)}(hs_encrypt_algos[4]h]hs_encrypt_algos[4]}(hj&hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj &ubah}(h]h ]h"]h$]h&]uh1jhj%ubj)}(hhh]h)}(hEncryption algorithms in use. There can be up to four algorithms in use at any time; valid algorithm codes are given in the super_encrypt_ table below.h](h|Encryption algorithms in use. There can be up to four algorithms in use at any time; valid algorithm codes are given in the }(hj&&hhhNhNubj)}(hsuper_encrypt_h]h super_encrypt}(hj.&hhhNhNubah}(h]h ]h"]h$]h&]name super_encryptj super-encryptuh1jhj&&jKubh table below.}(hj&&hhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhMhj#&ubah}(h]h ]h"]h$]h&]uh1jhj%ubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x258h]h0x258}(hj[&hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjX&ubah}(h]h ]h"]h$]h&]uh1jhjU&ubj)}(hhh]h)}(h__u8h]h__u8}(hjr&hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjo&ubah}(h]h ]h"]h$]h&]uh1jhjU&ubj)}(hhh]h)}(hs_encrypt_pw_salt[16]h]hs_encrypt_pw_salt[16]}(hj&hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj&ubah}(h]h ]h"]h$]h&]uh1jhjU&ubj)}(hhh]h)}(h1Salt for the string2key algorithm for encryption.h]h1Salt for the string2key algorithm for encryption.}(hj&hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj&ubah}(h]h ]h"]h$]h&]uh1jhjU&ubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x268h]h0x268}(hj&hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj&ubah}(h]h ]h"]h$]h&]uh1jhj&ubj)}(hhh]h)}(h__le32h]h__le32}(hj&hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj&ubah}(h]h ]h"]h$]h&]uh1jhj&ubj)}(hhh]h)}(h s_lpf_inoh]h s_lpf_ino}(hj&hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj&ubah}(h]h ]h"]h$]h&]uh1jhj&ubj)}(hhh]h)}(hInode number of lost+foundh]hInode number of lost+found}(hj'hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj'ubah}(h]h ]h"]h$]h&]uh1jhj&ubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x26Ch]h0x26C}(hj%'hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj"'ubah}(h]h ]h"]h$]h&]uh1jhj'ubj)}(hhh]h)}(h__le32h]h__le32}(hj<'hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj9'ubah}(h]h ]h"]h$]h&]uh1jhj'ubj)}(hhh]h)}(hs_prj_quota_inumh]hs_prj_quota_inum}(hjS'hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjP'ubah}(h]h ]h"]h$]h&]uh1jhj'ubj)}(hhh]h)}(h!Inode that tracks project quotas.h]h!Inode that tracks project quotas.}(hjj'hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjg'ubah}(h]h ]h"]h$]h&]uh1jhj'ubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x270h]h0x270}(hj'hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj'ubah}(h]h ]h"]h$]h&]uh1jhj'ubj)}(hhh]h)}(h__le32h]h__le32}(hj'hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj'ubah}(h]h ]h"]h$]h&]uh1jhj'ubj)}(hhh]h)}(hs_checksum_seedh]hs_checksum_seed}(hj'hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj'ubah}(h]h ]h"]h$]h&]uh1jhj'ubj)}(hhh]h)}(h[Checksum seed used for metadata_csum calculations. This value is crc32c(~0, $orig_fs_uuid).h]h[Checksum seed used for metadata_csum calculations. This value is crc32c(~0, $orig_fs_uuid).}(hj'hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj'ubah}(h]h ]h"]h$]h&]uh1jhj'ubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x274h]h0x274}(hj'hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj'ubah}(h]h ]h"]h$]h&]uh1jhj'ubj)}(hhh]h)}(h__u8h]h__u8}(hj(hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj(ubah}(h]h ]h"]h$]h&]uh1jhj'ubj)}(hhh]h)}(h s_wtime_hih]h s_wtime_hi}(hj(hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj(ubah}(h]h ]h"]h$]h&]uh1jhj'ubj)}(hhh]h)}(h"Upper 8 bits of the s_wtime field.h]h"Upper 8 bits of the s_wtime field.}(hj4(hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj1(ubah}(h]h ]h"]h$]h&]uh1jhj'ubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x275h]h0x275}(hjT(hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjQ(ubah}(h]h ]h"]h$]h&]uh1jhjN(ubj)}(hhh]h)}(h__u8h]h__u8}(hjk(hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjh(ubah}(h]h ]h"]h$]h&]uh1jhjN(ubj)}(hhh]h)}(h s_mtime_hih]h s_mtime_hi}(hj(hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj(ubah}(h]h ]h"]h$]h&]uh1jhjN(ubj)}(hhh]h)}(h"Upper 8 bits of the s_mtime field.h]h"Upper 8 bits of the s_mtime field.}(hj(hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj(ubah}(h]h ]h"]h$]h&]uh1jhjN(ubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x276h]h0x276}(hj(hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj(ubah}(h]h ]h"]h$]h&]uh1jhj(ubj)}(hhh]h)}(h__u8h]h__u8}(hj(hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj(ubah}(h]h ]h"]h$]h&]uh1jhj(ubj)}(hhh]h)}(hs_mkfs_time_hih]hs_mkfs_time_hi}(hj(hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj(ubah}(h]h ]h"]h$]h&]uh1jhj(ubj)}(hhh]h)}(h&Upper 8 bits of the s_mkfs_time field.h]h&Upper 8 bits of the s_mkfs_time field.}(hj(hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj(ubah}(h]h ]h"]h$]h&]uh1jhj(ubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x277h]h0x277}(hj)hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj)ubah}(h]h ]h"]h$]h&]uh1jhj)ubj)}(hhh]h)}(h__u8h]h__u8}(hj5)hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj2)ubah}(h]h ]h"]h$]h&]uh1jhj)ubj)}(hhh]h)}(hs_lastcheck_hih]hs_lastcheck_hi}(hjL)hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjI)ubah}(h]h ]h"]h$]h&]uh1jhj)ubj)}(hhh]h)}(h&Upper 8 bits of the s_lastcheck field.h]h&Upper 8 bits of the s_lastcheck field.}(hjc)hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj`)ubah}(h]h ]h"]h$]h&]uh1jhj)ubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x278h]h0x278}(hj)hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj)ubah}(h]h ]h"]h$]h&]uh1jhj})ubj)}(hhh]h)}(h__u8h]h__u8}(hj)hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj)ubah}(h]h ]h"]h$]h&]uh1jhj})ubj)}(hhh]h)}(hs_first_error_time_hih]hs_first_error_time_hi}(hj)hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj)ubah}(h]h ]h"]h$]h&]uh1jhj})ubj)}(hhh]h)}(h-Upper 8 bits of the s_first_error_time field.h]h-Upper 8 bits of the s_first_error_time field.}(hj)hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj)ubah}(h]h ]h"]h$]h&]uh1jhj})ubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x279h]h0x279}(hj)hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj)ubah}(h]h ]h"]h$]h&]uh1jhj)ubj)}(hhh]h)}(h__u8h]h__u8}(hj)hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj)ubah}(h]h ]h"]h$]h&]uh1jhj)ubj)}(hhh]h)}(hs_last_error_time_hih]hs_last_error_time_hi}(hj*hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj*ubah}(h]h ]h"]h$]h&]uh1jhj)ubj)}(hhh]h)}(h,Upper 8 bits of the s_last_error_time field.h]h,Upper 8 bits of the s_last_error_time field.}(hj-*hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj**ubah}(h]h ]h"]h$]h&]uh1jhj)ubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x27Ah]h0x27A}(hjM*hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjJ*ubah}(h]h ]h"]h$]h&]uh1jhjG*ubj)}(hhh]h)}(h\_\_u8h]h__u8}(hjd*hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhja*ubah}(h]h ]h"]h$]h&]uh1jhjG*ubj)}(hhh]h)}(hs\_first\_error\_errcodeh]hs_first_error_errcode}(hj{*hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjx*ubah}(h]h ]h"]h$]h&]uh1jhjG*ubj)}(hhh]h}(h]h ]h"]h$]h&]uh1jhjG*ubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x27Bh]h0x27B}(hj*hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj*ubah}(h]h ]h"]h$]h&]uh1jhj*ubj)}(hhh]h)}(h\_\_u8h]h__u8}(hj*hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj*ubah}(h]h ]h"]h$]h&]uh1jhj*ubj)}(hhh]h)}(hs\_last\_error\_errcodeh]hs_last_error_errcode}(hj*hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj*ubah}(h]h ]h"]h$]h&]uh1jhj*ubj)}(hhh]h}(h]h ]h"]h$]h&]uh1jhj*ubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x27Ch]h0x27C}(hj*hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj*ubah}(h]h ]h"]h$]h&]uh1jhj*ubj)}(hhh]h)}(h__le16h]h__le16}(hj+hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj+ubah}(h]h ]h"]h$]h&]uh1jhj*ubj)}(hhh]h)}(h s_encodingh]h s_encoding}(hj)+hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj&+ubah}(h]h ]h"]h$]h&]uh1jhj*ubj)}(hhh]h)}(hFilename charset encoding.h]hFilename charset encoding.}(hj@+hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj=+ubah}(h]h ]h"]h$]h&]uh1jhj*ubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x27Eh]h0x27E}(hj`+hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj]+ubah}(h]h ]h"]h$]h&]uh1jhjZ+ubj)}(hhh]h)}(h__le16h]h__le16}(hjw+hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjt+ubah}(h]h ]h"]h$]h&]uh1jhjZ+ubj)}(hhh]h)}(hs_encoding_flagsh]hs_encoding_flags}(hj+hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj+ubah}(h]h ]h"]h$]h&]uh1jhjZ+ubj)}(hhh]h)}(h Filename charset encoding flags.h]h Filename charset encoding flags.}(hj+hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj+ubah}(h]h ]h"]h$]h&]uh1jhjZ+ubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x280h]h0x280}(hj+hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj+ubah}(h]h ]h"]h$]h&]uh1jhj+ubj)}(hhh]h)}(h__le32h]h__le32}(hj+hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj+ubah}(h]h ]h"]h$]h&]uh1jhj+ubj)}(hhh]h)}(hs_orphan_file_inumh]hs_orphan_file_inum}(hj+hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj+ubah}(h]h ]h"]h$]h&]uh1jhj+ubj)}(hhh]h)}(hOrphan file inode number.h]hOrphan file inode number.}(hj ,hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj,ubah}(h]h ]h"]h$]h&]uh1jhj+ubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x284h]h0x284}(hj*,hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj',ubah}(h]h ]h"]h$]h&]uh1jhj$,ubj)}(hhh]h)}(h__le32h]h__le32}(hjA,hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj>,ubah}(h]h ]h"]h$]h&]uh1jhj$,ubj)}(hhh]h)}(hs_reserved[94]h]hs_reserved[94]}(hjX,hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjU,ubah}(h]h ]h"]h$]h&]uh1jhj$,ubj)}(hhh]h)}(h Padding to the end of the block.h]h Padding to the end of the block.}(hjo,hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjl,ubah}(h]h ]h"]h$]h&]uh1jhj$,ubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h0x3FCh]h0x3FC}(hj,hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj,ubah}(h]h ]h"]h$]h&]uh1jhj,ubj)}(hhh]h)}(h__le32h]h__le32}(hj,hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj,ubah}(h]h ]h"]h$]h&]uh1jhj,ubj)}(hhh]h)}(h s_checksumh]h s_checksum}(hj,hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj,ubah}(h]h ]h"]h$]h&]uh1jhj,ubj)}(hhh]h)}(hSuperblock checksum.h]hSuperblock checksum.}(hj,hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj,ubah}(h]h ]h"]h$]h&]uh1jhj,ubeh}(h]h ]h"]h$]h&]uh1j{hjubeh}(h]h ]h"]h$]h&]uh1jhjLubeh}(h]h ]h"]h$]h&]colsKuh1jJhjGubah}(h]h ]colwidths-givenah"]h$]h&]uh1jEhhhhhNhNubhtarget)}(h.. _super_state:h]h}(h]h ]h"]h$]h&]jjuh1j-hMhhhhhh referencedKubh)}(h:The superblock state is some combination of the following:h]h:The superblock state is some combination of the following:}(hj-hhhNhNubah}(h]jah ]h"] super_stateah$]h&]uh1hhhhMhhhhexpect_referenced_by_name}j-j-sexpect_referenced_by_id}jj-sj-KubjF)}(hhh]jK)}(hhh](jP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhj%-ubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKHuh1jOhj%-ubjw)}(hhh]j|)}(hhh](j)}(hhh]h)}(hValueh]hValue}(hjC-hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj@-ubah}(h]h ]h"]h$]h&]uh1jhj=-ubj)}(hhh]h)}(h Descriptionh]h Description}(hjZ-hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjW-ubah}(h]h ]h"]h$]h&]uh1jhj=-ubeh}(h]h ]h"]h$]h&]uh1j{hj:-ubah}(h]h ]h"]h$]h&]uh1jvhj%-ubj)}(hhh](j|)}(hhh](j)}(hhh]h)}(h0x0001h]h0x0001}(hj-hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj-ubah}(h]h ]h"]h$]h&]uh1jhj}-ubj)}(hhh]h)}(hCleanly umountedh]hCleanly umounted}(hj-hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj-ubah}(h]h ]h"]h$]h&]uh1jhj}-ubeh}(h]h ]h"]h$]h&]uh1j{hjz-ubj|)}(hhh](j)}(hhh]h)}(h0x0002h]h0x0002}(hj-hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj-ubah}(h]h ]h"]h$]h&]uh1jhj-ubj)}(hhh]h)}(hErrors detectedh]hErrors detected}(hj-hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj-ubah}(h]h ]h"]h$]h&]uh1jhj-ubeh}(h]h ]h"]h$]h&]uh1j{hjz-ubj|)}(hhh](j)}(hhh]h)}(h0x0004h]h0x0004}(hj-hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj-ubah}(h]h ]h"]h$]h&]uh1jhj-ubj)}(hhh]h)}(hOrphans being recoveredh]hOrphans being recovered}(hj.hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj.ubah}(h]h ]h"]h$]h&]uh1jhj-ubeh}(h]h ]h"]h$]h&]uh1j{hjz-ubeh}(h]h ]h"]h$]h&]uh1jhj%-ubeh}(h]h ]h"]h$]h&]colsKuh1jJhj"-ubah}(h]h ]j,ah"]h$]h&]uh1jEhhhhhNhNubj-)}(h.. _super_errors:h]h}(h]h ]h"]h$]h&]jj uh1j-hMhhhhhhj-Kubh)}(h4The superblock error policy is one of the following:h]h4The superblock error policy is one of the following:}(hj?.hhhNhNubah}(h]j ah ]h"] super_errorsah$]h&]uh1hhhhMhhhhj-}jK.j5.sj -}j j5.sj-KubjF)}(hhh]jK)}(hhh](jP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhjS.ubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKHuh1jOhjS.ubjw)}(hhh]j|)}(hhh](j)}(hhh]h)}(hValueh]hValue}(hjq.hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjn.ubah}(h]h ]h"]h$]h&]uh1jhjk.ubj)}(hhh]h)}(h Descriptionh]h Description}(hj.hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj.ubah}(h]h ]h"]h$]h&]uh1jhjk.ubeh}(h]h ]h"]h$]h&]uh1j{hjh.ubah}(h]h ]h"]h$]h&]uh1jvhjS.ubj)}(hhh](j|)}(hhh](j)}(hhh]h)}(h1h]h1}(hj.hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj.ubah}(h]h ]h"]h$]h&]uh1jhj.ubj)}(hhh]h)}(hContinueh]hContinue}(hj.hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj.ubah}(h]h ]h"]h$]h&]uh1jhj.ubeh}(h]h ]h"]h$]h&]uh1j{hj.ubj|)}(hhh](j)}(hhh]h)}(h2h]h2}(hj.hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj.ubah}(h]h ]h"]h$]h&]uh1jhj.ubj)}(hhh]h)}(hRemount read-onlyh]hRemount read-only}(hj.hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj.ubah}(h]h ]h"]h$]h&]uh1jhj.ubeh}(h]h ]h"]h$]h&]uh1j{hj.ubj|)}(hhh](j)}(hhh]h)}(h3h]h3}(hj/hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj/ubah}(h]h ]h"]h$]h&]uh1jhj/ubj)}(hhh]h)}(hPanich]hPanic}(hj6/hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj3/ubah}(h]h ]h"]h$]h&]uh1jhj/ubeh}(h]h ]h"]h$]h&]uh1j{hj.ubeh}(h]h ]h"]h$]h&]uh1jhjS.ubeh}(h]h ]h"]h$]h&]colsKuh1jJhjP.ubah}(h]h ]j,ah"]h$]h&]uh1jEhhhhhNhNubj-)}(h.. _super_creator:h]h}(h]h ]h"]h$]h&]jj uh1j-hM!hhhhhhj-Kubh)}(h/The filesystem creator is one of the following:h]h/The filesystem creator is one of the following:}(hjm/hhhNhNubah}(h]j ah ]h"] super_creatorah$]h&]uh1hhhhMhhhhj-}jy/jc/sj -}j jc/sj-KubjF)}(hhh]jK)}(hhh](jP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhj/ubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKHuh1jOhj/ubjw)}(hhh]j|)}(hhh](j)}(hhh]h)}(hValueh]hValue}(hj/hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj/ubah}(h]h ]h"]h$]h&]uh1jhj/ubj)}(hhh]h)}(h Descriptionh]h Description}(hj/hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM hj/ubah}(h]h ]h"]h$]h&]uh1jhj/ubeh}(h]h ]h"]h$]h&]uh1j{hj/ubah}(h]h ]h"]h$]h&]uh1jvhj/ubj)}(hhh](j|)}(hhh](j)}(hhh]h)}(h0h]h0}(hj/hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM!hj/ubah}(h]h ]h"]h$]h&]uh1jhj/ubj)}(hhh]h)}(hLinuxh]hLinux}(hj/hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM"hj/ubah}(h]h ]h"]h$]h&]uh1jhj/ubeh}(h]h ]h"]h$]h&]uh1j{hj/ubj|)}(hhh](j)}(hhh]h)}(hj.h]h1}(hj0hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM#hj0ubah}(h]h ]h"]h$]h&]uh1jhj0ubj)}(hhh]h)}(hHurdh]hHurd}(hj,0hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM$hj)0ubah}(h]h ]h"]h$]h&]uh1jhj0ubeh}(h]h ]h"]h$]h&]uh1j{hj/ubj|)}(hhh](j)}(hhh]h)}(hj.h]h2}(hjL0hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM%hjI0ubah}(h]h ]h"]h$]h&]uh1jhjF0ubj)}(hhh]h)}(hMasixh]hMasix}(hjb0hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM&hj_0ubah}(h]h ]h"]h$]h&]uh1jhjF0ubeh}(h]h ]h"]h$]h&]uh1j{hj/ubj|)}(hhh](j)}(hhh]h)}(hj!/h]h3}(hj0hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM'hj0ubah}(h]h ]h"]h$]h&]uh1jhj|0ubj)}(hhh]h)}(hFreeBSDh]hFreeBSD}(hj0hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM(hj0ubah}(h]h ]h"]h$]h&]uh1jhj|0ubeh}(h]h ]h"]h$]h&]uh1j{hj/ubj|)}(hhh](j)}(hhh]h)}(h4h]h4}(hj0hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM)hj0ubah}(h]h ]h"]h$]h&]uh1jhj0ubj)}(hhh]h)}(hLitesh]hLites}(hj0hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM*hj0ubah}(h]h ]h"]h$]h&]uh1jhj0ubeh}(h]h ]h"]h$]h&]uh1j{hj/ubeh}(h]h ]h"]h$]h&]uh1jhj/ubeh}(h]h ]h"]h$]h&]colsKuh1jJhj~/ubah}(h]h ]j,ah"]h$]h&]uh1jEhhhhhNhNubj-)}(h.. _super_revision:h]h}(h]h ]h"]h$]h&]jjC uh1j-hM6hhhhhhj-Kubh)}(h0The superblock revision is one of the following:h]h0The superblock revision is one of the following:}(hj1hhhNhNubah}(h]jC ah ]h"]super_revisionah$]h&]uh1hhhhM.hhhhj-}j1j0sj -}jC j0sj-KubjF)}(hhh]jK)}(hhh](jP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhj1ubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKHuh1jOhj1ubjw)}(hhh]j|)}(hhh](j)}(hhh]h)}(hValueh]hValue}(hj81hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM4hj51ubah}(h]h ]h"]h$]h&]uh1jhj21ubj)}(hhh]h)}(h Descriptionh]h Description}(hjO1hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM5hjL1ubah}(h]h ]h"]h$]h&]uh1jhj21ubeh}(h]h ]h"]h$]h&]uh1j{hj/1ubah}(h]h ]h"]h$]h&]uh1jvhj1ubj)}(hhh](j|)}(hhh](j)}(hhh]h)}(hj/h]h0}(hjx1hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM6hju1ubah}(h]h ]h"]h$]h&]uh1jhjr1ubj)}(hhh]h)}(hOriginal formath]hOriginal format}(hj1hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM7hj1ubah}(h]h ]h"]h$]h&]uh1jhjr1ubeh}(h]h ]h"]h$]h&]uh1j{hjo1ubj|)}(hhh](j)}(hhh]h)}(hj.h]h1}(hj1hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM8hj1ubah}(h]h ]h"]h$]h&]uh1jhj1ubj)}(hhh]h)}(h v2 format w/ dynamic inode sizesh]h v2 format w/ dynamic inode sizes}(hj1hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM9hj1ubah}(h]h ]h"]h$]h&]uh1jhj1ubeh}(h]h ]h"]h$]h&]uh1j{hjo1ubeh}(h]h ]h"]h$]h&]uh1jhj1ubeh}(h]h ]h"]h$]h&]colsKuh1jJhj1ubah}(h]h ]j,ah"]h$]h&]uh1jEhhhhhNhNubh)}(hJNote that ``EXT4_DYNAMIC_REV`` refers to a revision 1 or newer filesystem.h](h Note that }(hj1hhhNhNubj,)}(h``EXT4_DYNAMIC_REV``h]hEXT4_DYNAMIC_REV}(hj1hhhNhNubah}(h]h ]h"]h$]h&]uh1j+hj1ubh, refers to a revision 1 or newer filesystem.}(hj1hhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhM;hhhhubj-)}(h.. _super_compat:h]h}(h]h ]h"]h$]h&]jj uh1j-hMGhhhhhhj-Kubh)}(hRThe superblock compatible features field is a combination of any of the following:h]hRThe superblock compatible features field is a combination of any of the following:}(hj2hhhNhNubah}(h]j ah ]h"] super_compatah$]h&]uh1hhhhM?hhhhj-}j'2j2sj -}j j2sj-KubjF)}(hhh]jK)}(hhh](jP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhj/2ubjP)}(hhh]h}(h]h ]h"]h$]h&]jZK@uh1jOhj/2ubjw)}(hhh]j|)}(hhh](j)}(hhh]h)}(hValueh]hValue}(hjM2hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMFhjJ2ubah}(h]h ]h"]h$]h&]uh1jhjG2ubj)}(hhh]h)}(h Descriptionh]h Description}(hjd2hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMGhja2ubah}(h]h ]h"]h$]h&]uh1jhjG2ubeh}(h]h ]h"]h$]h&]uh1j{hjD2ubah}(h]h ]h"]h$]h&]uh1jvhj/2ubj)}(hhh](j|)}(hhh](j)}(hhh]h)}(h0x1h]h0x1}(hj2hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMHhj2ubah}(h]h ]h"]h$]h&]uh1jhj2ubj)}(hhh]h)}(h.Directory preallocation (COMPAT_DIR_PREALLOC).h]h.Directory preallocation (COMPAT_DIR_PREALLOC).}(hj2hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMIhj2ubah}(h]h ]h"]h$]h&]uh1jhj2ubeh}(h]h ]h"]h$]h&]uh1j{hj2ubj|)}(hhh](j)}(hhh]h)}(h0x2h]h0x2}(hj2hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMJhj2ubah}(h]h ]h"]h$]h&]uh1jhj2ubj)}(hhh]h)}(hS“imagic inodes”. Not clear from the code what this does (COMPAT_IMAGIC_INODES).h]hS“imagic inodes”. Not clear from the code what this does (COMPAT_IMAGIC_INODES).}(hj2hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMKhj2ubah}(h]h ]h"]h$]h&]uh1jhj2ubeh}(h]h ]h"]h$]h&]uh1j{hj2ubj|)}(hhh](j)}(hhh]h)}(h0x4h]h0x4}(hj2hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMMhj2ubah}(h]h ]h"]h$]h&]uh1jhj2ubj)}(hhh]h)}(h#Has a journal (COMPAT_HAS_JOURNAL).h]h#Has a journal (COMPAT_HAS_JOURNAL).}(hj3hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMNhj3ubah}(h]h ]h"]h$]h&]uh1jhj2ubeh}(h]h ]h"]h$]h&]uh1j{hj2ubj|)}(hhh](j)}(hhh]h)}(h0x8h]h0x8}(hj23hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMOhj/3ubah}(h]h ]h"]h$]h&]uh1jhj,3ubj)}(hhh]h)}(h/Supports extended attributes (COMPAT_EXT_ATTR).h]h/Supports extended attributes (COMPAT_EXT_ATTR).}(hjI3hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMPhjF3ubah}(h]h ]h"]h$]h&]uh1jhj,3ubeh}(h]h ]h"]h$]h&]uh1j{hj2ubj|)}(hhh](j)}(hhh]h)}(h0x10h]h0x10}(hji3hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMQhjf3ubah}(h]h ]h"]h$]h&]uh1jhjc3ubj)}(hhh]h)}(hhHas reserved GDT blocks for filesystem expansion (COMPAT_RESIZE_INODE). Requires RO_COMPAT_SPARSE_SUPER.h]hhHas reserved GDT blocks for filesystem expansion (COMPAT_RESIZE_INODE). Requires RO_COMPAT_SPARSE_SUPER.}(hj3hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMRhj}3ubah}(h]h ]h"]h$]h&]uh1jhjc3ubeh}(h]h ]h"]h$]h&]uh1j{hj2ubj|)}(hhh](j)}(hhh]h)}(h0x20h]h0x20}(hj3hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMThj3ubah}(h]h ]h"]h$]h&]uh1jhj3ubj)}(hhh]h)}(h)Has directory indices (COMPAT_DIR_INDEX).h]h)Has directory indices (COMPAT_DIR_INDEX).}(hj3hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMUhj3ubah}(h]h ]h"]h$]h&]uh1jhj3ubeh}(h]h ]h"]h$]h&]uh1j{hj2ubj|)}(hhh](j)}(hhh]h)}(h0x40h]h0x40}(hj3hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMVhj3ubah}(h]h ]h"]h$]h&]uh1jhj3ubj)}(hhh]h)}(hg“Lazy BG”. Not in Linux kernel, seems to have been for uninitialized block groups? (COMPAT_LAZY_BG)h]hg“Lazy BG”. Not in Linux kernel, seems to have been for uninitialized block groups? (COMPAT_LAZY_BG)}(hj3hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMWhj3ubah}(h]h ]h"]h$]h&]uh1jhj3ubeh}(h]h ]h"]h$]h&]uh1j{hj2ubj|)}(hhh](j)}(hhh]h)}(h0x80h]h0x80}(hj4hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMYhj 4ubah}(h]h ]h"]h$]h&]uh1jhj4ubj)}(hhh]h)}(h6“Exclude inode”. Not used. (COMPAT_EXCLUDE_INODE).h]h6“Exclude inode”. Not used. (COMPAT_EXCLUDE_INODE).}(hj%4hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMZhj"4ubah}(h]h ]h"]h$]h&]uh1jhj4ubeh}(h]h ]h"]h$]h&]uh1j{hj2ubj|)}(hhh](j)}(hhh]h)}(h0x100h]h0x100}(hjE4hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM[hjB4ubah}(h]h ]h"]h$]h&]uh1jhj?4ubj)}(hhh]h)}(h“Exclude bitmap”. Seems to be used to indicate the presence of snapshot-related exclude bitmaps? Not defined in kernel or used in e2fsprogs (COMPAT_EXCLUDE_BITMAP).h]h“Exclude bitmap”. Seems to be used to indicate the presence of snapshot-related exclude bitmaps? Not defined in kernel or used in e2fsprogs (COMPAT_EXCLUDE_BITMAP).}(hj\4hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM\hjY4ubah}(h]h ]h"]h$]h&]uh1jhj?4ubeh}(h]h ]h"]h$]h&]uh1j{hj2ubj|)}(hhh](j)}(hhh]h)}(h0x200h]h0x200}(hj|4hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM_hjy4ubah}(h]h ]h"]h$]h&]uh1jhjv4ubj)}(hhh]h)}(hSparse Super Block, v2. If this flag is set, the SB field s_backup_bgs points to the two block groups that contain backup superblocks (COMPAT_SPARSE_SUPER2).h]hSparse Super Block, v2. If this flag is set, the SB field s_backup_bgs points to the two block groups that contain backup superblocks (COMPAT_SPARSE_SUPER2).}(hj4hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM`hj4ubah}(h]h ]h"]h$]h&]uh1jhjv4ubeh}(h]h ]h"]h$]h&]uh1j{hj2ubj|)}(hhh](j)}(hhh]h)}(h0x400h]h0x400}(hj4hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMchj4ubah}(h]h ]h"]h$]h&]uh1jhj4ubj)}(hhh]h)}(hXFast commits supported. Although fast commits blocks are backward incompatible, fast commit blocks are not always present in the journal. If fast commit blocks are present in the journal, JBD2 incompat feature (JBD2_FEATURE_INCOMPAT_FAST_COMMIT) gets set (COMPAT_FAST_COMMIT).h]hXFast commits supported. Although fast commits blocks are backward incompatible, fast commit blocks are not always present in the journal. If fast commit blocks are present in the journal, JBD2 incompat feature (JBD2_FEATURE_INCOMPAT_FAST_COMMIT) gets set (COMPAT_FAST_COMMIT).}(hj4hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMdhj4ubah}(h]h ]h"]h$]h&]uh1jhj4ubeh}(h]h ]h"]h$]h&]uh1j{hj2ubj|)}(hhh](j)}(hhh]h)}(h0x1000h]h0x1000}(hj4hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMjhj4ubah}(h]h ]h"]h$]h&]uh1jhj4ubj)}(hhh]h)}(hOrphan file allocated. This is the special file for more efficient tracking of unlinked but still open inodes. When there may be any entries in the file, we additionally set proper rocompat feature (RO_COMPAT_ORPHAN_PRESENT).h]hOrphan file allocated. This is the special file for more efficient tracking of unlinked but still open inodes. When there may be any entries in the file, we additionally set proper rocompat feature (RO_COMPAT_ORPHAN_PRESENT).}(hj5hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMkhj4ubah}(h]h ]h"]h$]h&]uh1jhj4ubeh}(h]h ]h"]h$]h&]uh1j{hj2ubeh}(h]h ]h"]h$]h&]uh1jhj/2ubeh}(h]h ]h"]h$]h&]colsKuh1jJhj,2ubah}(h]h ]j,ah"]h$]h&]uh1jEhhhhhNhNubj-)}(h.. _super_incompat:h]h}(h]h ]h"]h$]h&]jjuh1j-hMzhhhhhhj-Kubh)}(hTThe superblock incompatible features field is a combination of any of the following:h]hTThe superblock incompatible features field is a combination of any of the following:}(hj85hhhNhNubah}(h]jah ]h"]super_incompatah$]h&]uh1hhhhMrhhhhj-}jD5j.5sj -}jj.5sj-KubjF)}(hhh]jK)}(hhh](jP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhjL5ubjP)}(hhh]h}(h]h ]h"]h$]h&]jZK@uh1jOhjL5ubjw)}(hhh]j|)}(hhh](j)}(hhh]h)}(hValueh]hValue}(hjj5hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMyhjg5ubah}(h]h ]h"]h$]h&]uh1jhjd5ubj)}(hhh]h)}(h Descriptionh]h Description}(hj5hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMzhj~5ubah}(h]h ]h"]h$]h&]uh1jhjd5ubeh}(h]h ]h"]h$]h&]uh1j{hja5ubah}(h]h ]h"]h$]h&]uh1jvhjL5ubj)}(hhh](j|)}(hhh](j)}(hhh]h)}(h0x1h]h0x1}(hj5hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM{hj5ubah}(h]h ]h"]h$]h&]uh1jhj5ubj)}(hhh]h)}(h#Compression (INCOMPAT_COMPRESSION).h]h#Compression (INCOMPAT_COMPRESSION).}(hj5hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM|hj5ubah}(h]h ]h"]h$]h&]uh1jhj5ubeh}(h]h ]h"]h$]h&]uh1j{hj5ubj|)}(hhh](j)}(hhh]h)}(h0x2h]h0x2}(hj5hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM}hj5ubah}(h]h ]h"]h$]h&]uh1jhj5ubj)}(hhh]h)}(hWDirectory entries record the file type. See ext4_dir_entry_2 below (INCOMPAT_FILETYPE).h]hWDirectory entries record the file type. See ext4_dir_entry_2 below (INCOMPAT_FILETYPE).}(hj5hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM~hj5ubah}(h]h ]h"]h$]h&]uh1jhj5ubeh}(h]h ]h"]h$]h&]uh1j{hj5ubj|)}(hhh](j)}(hhh]h)}(h0x4h]h0x4}(hj6hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj6ubah}(h]h ]h"]h$]h&]uh1jhj6ubj)}(hhh]h)}(h-Filesystem needs recovery (INCOMPAT_RECOVER).h]h-Filesystem needs recovery (INCOMPAT_RECOVER).}(hj/6hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj,6ubah}(h]h ]h"]h$]h&]uh1jhj6ubeh}(h]h ]h"]h$]h&]uh1j{hj5ubj|)}(hhh](j)}(hhh]h)}(h0x8h]h0x8}(hjO6hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjL6ubah}(h]h ]h"]h$]h&]uh1jhjI6ubj)}(hhh]h)}(h@Filesystem has a separate journal device (INCOMPAT_JOURNAL_DEV).h]h@Filesystem has a separate journal device (INCOMPAT_JOURNAL_DEV).}(hjf6hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjc6ubah}(h]h ]h"]h$]h&]uh1jhjI6ubeh}(h]h ]h"]h$]h&]uh1j{hj5ubj|)}(hhh](j)}(hhh]h)}(h0x10h]h0x10}(hj6hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj6ubah}(h]h ]h"]h$]h&]uh1jhj6ubj)}(hhh]h)}(hQMeta block groups. See the earlier discussion of this feature (INCOMPAT_META_BG).h]hQMeta block groups. See the earlier discussion of this feature (INCOMPAT_META_BG).}(hj6hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj6ubah}(h]h ]h"]h$]h&]uh1jhj6ubeh}(h]h ]h"]h$]h&]uh1j{hj5ubj|)}(hhh](j)}(hhh]h)}(h0x40h]h0x40}(hj6hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj6ubah}(h]h ]h"]h$]h&]uh1jhj6ubj)}(hhh]h)}(h8Files in this filesystem use extents (INCOMPAT_EXTENTS).h]h8Files in this filesystem use extents (INCOMPAT_EXTENTS).}(hj6hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj6ubah}(h]h ]h"]h$]h&]uh1jhj6ubeh}(h]h ]h"]h$]h&]uh1j{hj5ubj|)}(hhh](j)}(hhh]h)}(h0x80h]h0x80}(hj6hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj6ubah}(h]h ]h"]h$]h&]uh1jhj6ubj)}(hhh]h)}(h9Enable a filesystem size of 2^64 blocks (INCOMPAT_64BIT).h]h9Enable a filesystem size of 2^64 blocks (INCOMPAT_64BIT).}(hj 7hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj7ubah}(h]h ]h"]h$]h&]uh1jhj6ubeh}(h]h ]h"]h$]h&]uh1j{hj5ubj|)}(hhh](j)}(hhh]h)}(h0x100h]h0x100}(hj+7hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj(7ubah}(h]h ]h"]h$]h&]uh1jhj%7ubj)}(hhh]h)}(h)Multiple mount protection (INCOMPAT_MMP).h]h)Multiple mount protection (INCOMPAT_MMP).}(hjB7hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj?7ubah}(h]h ]h"]h$]h&]uh1jhj%7ubeh}(h]h ]h"]h$]h&]uh1j{hj5ubj|)}(hhh](j)}(hhh]h)}(h0x200h]h0x200}(hjb7hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj_7ubah}(h]h ]h"]h$]h&]uh1jhj\7ubj)}(hhh]h)}(hUFlexible block groups. See the earlier discussion of this feature (INCOMPAT_FLEX_BG).h]hUFlexible block groups. See the earlier discussion of this feature (INCOMPAT_FLEX_BG).}(hjy7hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjv7ubah}(h]h ]h"]h$]h&]uh1jhj\7ubeh}(h]h ]h"]h$]h&]uh1j{hj5ubj|)}(hhh](j)}(hhh]h)}(h0x400h]h0x400}(hj7hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj7ubah}(h]h ]h"]h$]h&]uh1jhj7ubj)}(hhh]h)}(hPInodes can be used to store large extended attribute values (INCOMPAT_EA_INODE).h]hPInodes can be used to store large extended attribute values (INCOMPAT_EA_INODE).}(hj7hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj7ubah}(h]h ]h"]h$]h&]uh1jhj7ubeh}(h]h ]h"]h$]h&]uh1j{hj5ubj|)}(hhh](j)}(hhh]h)}(h0x1000h]h0x1000}(hj7hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj7ubah}(h]h ]h"]h$]h&]uh1jhj7ubj)}(hhh]h)}(h>Data in directory entry (INCOMPAT_DIRDATA). (Not implemented?)h]h>Data in directory entry (INCOMPAT_DIRDATA). (Not implemented?)}(hj7hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj7ubah}(h]h ]h"]h$]h&]uh1jhj7ubeh}(h]h ]h"]h$]h&]uh1j{hj5ubj|)}(hhh](j)}(hhh]h)}(h0x2000h]h0x2000}(hj8hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj8ubah}(h]h ]h"]h$]h&]uh1jhj8ubj)}(hhh]h)}(hXMetadata checksum seed is stored in the superblock. This feature enables the administrator to change the UUID of a metadata_csum filesystem while the filesystem is mounted; without it, the checksum definition requires all metadata blocks to be rewritten (INCOMPAT_CSUM_SEED).h]hXMetadata checksum seed is stored in the superblock. This feature enables the administrator to change the UUID of a metadata_csum filesystem while the filesystem is mounted; without it, the checksum definition requires all metadata blocks to be rewritten (INCOMPAT_CSUM_SEED).}(hj8hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj8ubah}(h]h ]h"]h$]h&]uh1jhj8ubeh}(h]h ]h"]h$]h&]uh1j{hj5ubj|)}(hhh](j)}(hhh]h)}(h0x4000h]h0x4000}(hj>8hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj;8ubah}(h]h ]h"]h$]h&]uh1jhj88ubj)}(hhh]h)}(hXLarge directory >2GB or 3-level htree (INCOMPAT_LARGEDIR). Prior to this feature, directories could not be larger than 4GiB and could not have an htree more than 2 levels deep. If this feature is enabled, directories can be larger than 4GiB and have a maximum htree depth of 3.h]hXLarge directory >2GB or 3-level htree (INCOMPAT_LARGEDIR). Prior to this feature, directories could not be larger than 4GiB and could not have an htree more than 2 levels deep. If this feature is enabled, directories can be larger than 4GiB and have a maximum htree depth of 3.}(hjU8hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjR8ubah}(h]h ]h"]h$]h&]uh1jhj88ubeh}(h]h ]h"]h$]h&]uh1j{hj5ubj|)}(hhh](j)}(hhh]h)}(h0x8000h]h0x8000}(hju8hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjr8ubah}(h]h ]h"]h$]h&]uh1jhjo8ubj)}(hhh]h)}(h%Data in inode (INCOMPAT_INLINE_DATA).h]h%Data in inode (INCOMPAT_INLINE_DATA).}(hj8hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj8ubah}(h]h ]h"]h$]h&]uh1jhjo8ubeh}(h]h ]h"]h$]h&]uh1j{hj5ubj|)}(hhh](j)}(hhh]h)}(h0x10000h]h0x10000}(hj8hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj8ubah}(h]h ]h"]h$]h&]uh1jhj8ubj)}(hhh]h)}(hCEncrypted inodes are present on the filesystem. (INCOMPAT_ENCRYPT).h]hCEncrypted inodes are present on the filesystem. (INCOMPAT_ENCRYPT).}(hj8hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj8ubah}(h]h ]h"]h$]h&]uh1jhj8ubeh}(h]h ]h"]h$]h&]uh1j{hj5ubeh}(h]h ]h"]h$]h&]uh1jhjL5ubeh}(h]h ]h"]h$]h&]colsKuh1jJhjI5ubah}(h]h ]j,ah"]h$]h&]uh1jEhhhhhNhNubj-)}(h.. _super_rocompat:h]h}(h]h ]h"]h$]h&]jjuh1j-hMhhhhhhj-Kubh)}(h\The superblock read-only compatible features field is a combination of any of the following:h]h\The superblock read-only compatible features field is a combination of any of the following:}(hj8hhhNhNubah}(h]jah ]h"]super_rocompatah$]h&]uh1hhhhMhhhhj-}j9j8sj -}jj8sj-KubjF)}(hhh]jK)}(hhh](jP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhj9ubjP)}(hhh]h}(h]h ]h"]h$]h&]jZK@uh1jOhj9ubjw)}(hhh]j|)}(hhh](j)}(hhh]h)}(hValueh]hValue}(hj,9hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj)9ubah}(h]h ]h"]h$]h&]uh1jhj&9ubj)}(hhh]h)}(h Descriptionh]h Description}(hjC9hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj@9ubah}(h]h ]h"]h$]h&]uh1jhj&9ubeh}(h]h ]h"]h$]h&]uh1j{hj#9ubah}(h]h ]h"]h$]h&]uh1jvhj9ubj)}(hhh](j|)}(hhh](j)}(hhh]h)}(h0x1h]h0x1}(hjl9hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhji9ubah}(h]h ]h"]h$]h&]uh1jhjf9ubj)}(hhh]h)}(hXSparse superblocks. See the earlier discussion of this feature (RO_COMPAT_SPARSE_SUPER).h]hXSparse superblocks. See the earlier discussion of this feature (RO_COMPAT_SPARSE_SUPER).}(hj9hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj9ubah}(h]h ]h"]h$]h&]uh1jhjf9ubeh}(h]h ]h"]h$]h&]uh1j{hjc9ubj|)}(hhh](j)}(hhh]h)}(h0x2h]h0x2}(hj9hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj9ubah}(h]h ]h"]h$]h&]uh1jhj9ubj)}(hhh]h)}(hWThis filesystem has been used to store a file greater than 2GiB (RO_COMPAT_LARGE_FILE).h]hWThis filesystem has been used to store a file greater than 2GiB (RO_COMPAT_LARGE_FILE).}(hj9hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj9ubah}(h]h ]h"]h$]h&]uh1jhj9ubeh}(h]h ]h"]h$]h&]uh1j{hjc9ubj|)}(hhh](j)}(hhh]h)}(h0x4h]h0x4}(hj9hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj9ubah}(h]h ]h"]h$]h&]uh1jhj9ubj)}(hhh]h)}(h6Not used in kernel or e2fsprogs (RO_COMPAT_BTREE_DIR).h]h6Not used in kernel or e2fsprogs (RO_COMPAT_BTREE_DIR).}(hj9hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj9ubah}(h]h ]h"]h$]h&]uh1jhj9ubeh}(h]h ]h"]h$]h&]uh1j{hjc9ubj|)}(hhh](j)}(hhh]h)}(h0x8h]h0x8}(hj:hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj:ubah}(h]h ]h"]h$]h&]uh1jhj :ubj)}(hhh]h)}(hThis filesystem has files whose sizes are represented in units of logical blocks, not 512-byte sectors. This implies a very large file indeed! (RO_COMPAT_HUGE_FILE)h]hThis filesystem has files whose sizes are represented in units of logical blocks, not 512-byte sectors. This implies a very large file indeed! (RO_COMPAT_HUGE_FILE)}(hj(:hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj%:ubah}(h]h ]h"]h$]h&]uh1jhj :ubeh}(h]h ]h"]h$]h&]uh1j{hjc9ubj|)}(hhh](j)}(hhh]h)}(h0x10h]h0x10}(hjH:hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjE:ubah}(h]h ]h"]h$]h&]uh1jhjB:ubj)}(hhh]h)}(hGroup descriptors have checksums. In addition to detecting corruption, this is useful for lazy formatting with uninitialized groups (RO_COMPAT_GDT_CSUM).h]hGroup descriptors have checksums. In addition to detecting corruption, this is useful for lazy formatting with uninitialized groups (RO_COMPAT_GDT_CSUM).}(hj_:hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj\:ubah}(h]h ]h"]h$]h&]uh1jhjB:ubeh}(h]h ]h"]h$]h&]uh1j{hjc9ubj|)}(hhh](j)}(hhh]h)}(h0x20h]h0x20}(hj:hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj|:ubah}(h]h ]h"]h$]h&]uh1jhjy:ubj)}(hhh]h)}(hIndicates that the old ext3 32,000 subdirectory limit no longer applies (RO_COMPAT_DIR_NLINK). A directory's i_links_count will be set to 1 if it is incremented past 64,999.h]hIndicates that the old ext3 32,000 subdirectory limit no longer applies (RO_COMPAT_DIR_NLINK). A directory’s i_links_count will be set to 1 if it is incremented past 64,999.}(hj:hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj:ubah}(h]h ]h"]h$]h&]uh1jhjy:ubeh}(h]h ]h"]h$]h&]uh1j{hjc9ubj|)}(hhh](j)}(hhh]h)}(h0x40h]h0x40}(hj:hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj:ubah}(h]h ]h"]h$]h&]uh1jhj:ubj)}(hhh]h)}(hMIndicates that large inodes exist on this filesystem (RO_COMPAT_EXTRA_ISIZE).h]hMIndicates that large inodes exist on this filesystem (RO_COMPAT_EXTRA_ISIZE).}(hj:hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj:ubah}(h]h ]h"]h$]h&]uh1jhj:ubeh}(h]h ]h"]h$]h&]uh1j{hjc9ubj|)}(hhh](j)}(hhh]h)}(h0x80h]h0x80}(hj:hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj:ubah}(h]h ]h"]h$]h&]uh1jhj:ubj)}(hhh]h)}(h8This filesystem has a snapshot (RO_COMPAT_HAS_SNAPSHOT).h]h8This filesystem has a snapshot (RO_COMPAT_HAS_SNAPSHOT).}(hj;hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj;ubah}(h]h ]h"]h$]h&]uh1jhj:ubeh}(h]h ]h"]h$]h&]uh1j{hjc9ubj|)}(hhh](j)}(hhh]h)}(h0x100h]h0x100}(hj$;hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj!;ubah}(h]h ]h"]h$]h&]uh1jhj;ubj)}(hhh]h)}(h$`Quota `__ (RO_COMPAT_QUOTA).h](j)}(h`Quota `__h]hQuota}(hj?;hhhNhNubah}(h]h ]h"]h$]h&]nameQuotaj$Quotauh1jhj;;ubh (RO_COMPAT_QUOTA).}(hj;;hhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhMhj8;ubah}(h]h ]h"]h$]h&]uh1jhj;ubeh}(h]h ]h"]h$]h&]uh1j{hjc9ubj|)}(hhh](j)}(hhh]h)}(h0x200h]h0x200}(hjl;hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhji;ubah}(h]h ]h"]h$]h&]uh1jhjf;ubj)}(hhh]h)}(hThis filesystem supports “bigalloc”, which means that file extents are tracked in units of clusters (of blocks) instead of blocks (RO_COMPAT_BIGALLOC).h]hThis filesystem supports “bigalloc”, which means that file extents are tracked in units of clusters (of blocks) instead of blocks (RO_COMPAT_BIGALLOC).}(hj;hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj;ubah}(h]h ]h"]h$]h&]uh1jhjf;ubeh}(h]h ]h"]h$]h&]uh1j{hjc9ubj|)}(hhh](j)}(hhh]h)}(h0x400h]h0x400}(hj;hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj;ubah}(h]h ]h"]h$]h&]uh1jhj;ubj)}(hhh]h)}(hThis filesystem supports metadata checksumming. (RO_COMPAT_METADATA_CSUM; implies RO_COMPAT_GDT_CSUM, though GDT_CSUM must not be set)h]hThis filesystem supports metadata checksumming. (RO_COMPAT_METADATA_CSUM; implies RO_COMPAT_GDT_CSUM, though GDT_CSUM must not be set)}(hj;hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj;ubah}(h]h ]h"]h$]h&]uh1jhj;ubeh}(h]h ]h"]h$]h&]uh1j{hjc9ubj|)}(hhh](j)}(hhh]h)}(h0x800h]h0x800}(hj;hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj;ubah}(h]h ]h"]h$]h&]uh1jhj;ubj)}(hhh]h)}(hfFilesystem supports replicas. This feature is neither in the kernel nor e2fsprogs. (RO_COMPAT_REPLICA)h]hfFilesystem supports replicas. This feature is neither in the kernel nor e2fsprogs. (RO_COMPAT_REPLICA)}(hj;hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj;ubah}(h]h ]h"]h$]h&]uh1jhj;ubeh}(h]h ]h"]h$]h&]uh1j{hjc9ubj|)}(hhh](j)}(hhh]h)}(h0x1000h]h0x1000}(hj<hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj<ubah}(h]h ]h"]h$]h&]uh1jhj <ubj)}(hhh]h)}(hRead-only filesystem image; the kernel will not mount this image read-write and most tools will refuse to write to the image. (RO_COMPAT_READONLY)h]hRead-only filesystem image; the kernel will not mount this image read-write and most tools will refuse to write to the image. (RO_COMPAT_READONLY)}(hj(<hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj%<ubah}(h]h ]h"]h$]h&]uh1jhj <ubeh}(h]h ]h"]h$]h&]uh1j{hjc9ubj|)}(hhh](j)}(hhh]h)}(h0x2000h]h0x2000}(hjH<hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjE<ubah}(h]h ]h"]h$]h&]uh1jhjB<ubj)}(hhh]h)}(h5Filesystem tracks project quotas. (RO_COMPAT_PROJECT)h]h5Filesystem tracks project quotas. (RO_COMPAT_PROJECT)}(hj_<hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj\<ubah}(h]h ]h"]h$]h&]uh1jhjB<ubeh}(h]h ]h"]h$]h&]uh1j{hjc9ubj|)}(hhh](j)}(hhh]h)}(h0x8000h]h0x8000}(hj<hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj|<ubah}(h]h ]h"]h$]h&]uh1jhjy<ubj)}(hhh]h)}(hBVerity inodes may be present on the filesystem. (RO_COMPAT_VERITY)h]hBVerity inodes may be present on the filesystem. (RO_COMPAT_VERITY)}(hj<hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj<ubah}(h]h ]h"]h$]h&]uh1jhjy<ubeh}(h]h ]h"]h$]h&]uh1j{hjc9ubj|)}(hhh](j)}(hhh]h)}(h0x10000h]h0x10000}(hj<hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj<ubah}(h]h ]h"]h$]h&]uh1jhj<ubj)}(hhh]h)}(hIndicates orphan file may have valid orphan entries and thus we need to clean them up when mounting the filesystem (RO_COMPAT_ORPHAN_PRESENT).h]hIndicates orphan file may have valid orphan entries and thus we need to clean them up when mounting the filesystem (RO_COMPAT_ORPHAN_PRESENT).}(hj<hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj<ubah}(h]h ]h"]h$]h&]uh1jhj<ubeh}(h]h ]h"]h$]h&]uh1j{hjc9ubeh}(h]h ]h"]h$]h&]uh1jhj9ubeh}(h]h ]h"]h$]h&]colsKuh1jJhj 9ubah}(h]h ]j,ah"]h$]h&]uh1jEhhhhhNhNubj-)}(h.. _super_def_hash:h]h}(h]h ]h"]h$]h&]jjuh1j-hMhhhhhhj-Kubh)}(h9The ``s_def_hash_version`` field is one of the following:h](hThe }(hj=hhhNhNubj,)}(h``s_def_hash_version``h]hs_def_hash_version}(hj =hhhNhNubah}(h]h ]h"]h$]h&]uh1j+hj=ubh field is one of the following:}(hj=hhhNhNubeh}(h]jah ]h"]super_def_hashah$]h&]uh1hhhhMhhhhj-}j"=j<sj -}jj<sj-KubjF)}(hhh]jK)}(hhh](jP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhj*=ubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKHuh1jOhj*=ubjw)}(hhh]j|)}(hhh](j)}(hhh]h)}(hValueh]hValue}(hjH=hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjE=ubah}(h]h ]h"]h$]h&]uh1jhjB=ubj)}(hhh]h)}(h Descriptionh]h Description}(hj_=hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj\=ubah}(h]h ]h"]h$]h&]uh1jhjB=ubeh}(h]h ]h"]h$]h&]uh1j{hj?=ubah}(h]h ]h"]h$]h&]uh1jvhj*=ubj)}(hhh](j|)}(hhh](j)}(hhh]h)}(h0x0h]h0x0}(hj=hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj=ubah}(h]h ]h"]h$]h&]uh1jhj=ubj)}(hhh]h)}(hLegacy.h]hLegacy.}(hj=hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj=ubah}(h]h ]h"]h$]h&]uh1jhj=ubeh}(h]h ]h"]h$]h&]uh1j{hj=ubj|)}(hhh](j)}(hhh]h)}(h0x1h]h0x1}(hj=hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj=ubah}(h]h ]h"]h$]h&]uh1jhj=ubj)}(hhh]h)}(h Half MD4.h]h Half MD4.}(hj=hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj=ubah}(h]h ]h"]h$]h&]uh1jhj=ubeh}(h]h ]h"]h$]h&]uh1j{hj=ubj|)}(hhh](j)}(hhh]h)}(h0x2h]h0x2}(hj=hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj=ubah}(h]h ]h"]h$]h&]uh1jhj=ubj)}(hhh]h)}(hTea.h]hTea.}(hj >hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj >ubah}(h]h ]h"]h$]h&]uh1jhj=ubeh}(h]h ]h"]h$]h&]uh1j{hj=ubj|)}(hhh](j)}(hhh]h)}(h0x3h]h0x3}(hj->hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj*>ubah}(h]h ]h"]h$]h&]uh1jhj'>ubj)}(hhh]h)}(hLegacy, unsigned.h]hLegacy, unsigned.}(hjD>hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjA>ubah}(h]h ]h"]h$]h&]uh1jhj'>ubeh}(h]h ]h"]h$]h&]uh1j{hj=ubj|)}(hhh](j)}(hhh]h)}(h0x4h]h0x4}(hjd>hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhja>ubah}(h]h ]h"]h$]h&]uh1jhj^>ubj)}(hhh]h)}(hHalf MD4, unsigned.h]hHalf MD4, unsigned.}(hj{>hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjx>ubah}(h]h ]h"]h$]h&]uh1jhj^>ubeh}(h]h ]h"]h$]h&]uh1j{hj=ubj|)}(hhh](j)}(hhh]h)}(h0x5h]h0x5}(hj>hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj>ubah}(h]h ]h"]h$]h&]uh1jhj>ubj)}(hhh]h)}(hTea, unsigned.h]hTea, unsigned.}(hj>hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj>ubah}(h]h ]h"]h$]h&]uh1jhj>ubeh}(h]h ]h"]h$]h&]uh1j{hj=ubeh}(h]h ]h"]h$]h&]uh1jhj*=ubeh}(h]h ]h"]h$]h&]colsKuh1jJhj'=ubah}(h]h ]j,ah"]h$]h&]uh1jEhhhhhNhNubj-)}(h.. _super_mountopts:h]h}(h]h ]h"]h$]h&]jj'uh1j-hMhhhhhhj-Kubh)}(hGThe ``s_default_mount_opts`` field is any combination of the following:h](hThe }(hj>hhhNhNubj,)}(h``s_default_mount_opts``h]hs_default_mount_opts}(hj>hhhNhNubah}(h]h ]h"]h$]h&]uh1j+hj>ubh+ field is any combination of the following:}(hj>hhhNhNubeh}(h]j'ah ]h"]super_mountoptsah$]h&]uh1hhhhMhhhhj-}j?j>sj -}j'j>sj-KubjF)}(hhh]jK)}(hhh](jP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhj?ubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKHuh1jOhj?ubjw)}(hhh]j|)}(hhh](j)}(hhh]h)}(hValueh]hValue}(hj-?hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj*?ubah}(h]h ]h"]h$]h&]uh1jhj'?ubj)}(hhh]h)}(h Descriptionh]h Description}(hjD?hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjA?ubah}(h]h ]h"]h$]h&]uh1jhj'?ubeh}(h]h ]h"]h$]h&]uh1j{hj$?ubah}(h]h ]h"]h$]h&]uh1jvhj?ubj)}(hhh](j|)}(hhh](j)}(hhh]h)}(h0x0001h]h0x0001}(hjm?hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjj?ubah}(h]h ]h"]h$]h&]uh1jhjg?ubj)}(hhh]h)}(h6Print debugging info upon (re)mount. (EXT4_DEFM_DEBUG)h]h6Print debugging info upon (re)mount. (EXT4_DEFM_DEBUG)}(hj?hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj?ubah}(h]h ]h"]h$]h&]uh1jhjg?ubeh}(h]h ]h"]h$]h&]uh1j{hjd?ubj|)}(hhh](j)}(hhh]h)}(h0x0002h]h0x0002}(hj?hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj?ubah}(h]h ]h"]h$]h&]uh1jhj?ubj)}(hhh]h)}(hwNew files take the gid of the containing directory (instead of the fsgid of the current process). (EXT4_DEFM_BSDGROUPS)h]hwNew files take the gid of the containing directory (instead of the fsgid of the current process). (EXT4_DEFM_BSDGROUPS)}(hj?hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj?ubah}(h]h ]h"]h$]h&]uh1jhj?ubeh}(h]h ]h"]h$]h&]uh1j{hjd?ubj|)}(hhh](j)}(hhh]h)}(h0x0004h]h0x0004}(hj?hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj?ubah}(h]h ]h"]h$]h&]uh1jhj?ubj)}(hhh]h)}(hFSupport userspace-provided extended attributes. (EXT4_DEFM_XATTR_USER)h]hFSupport userspace-provided extended attributes. (EXT4_DEFM_XATTR_USER)}(hj?hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM hj?ubah}(h]h ]h"]h$]h&]uh1jhj?ubeh}(h]h ]h"]h$]h&]uh1j{hjd?ubj|)}(hhh](j)}(hhh]h)}(h0x0008h]h0x0008}(hj@hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM hj@ubah}(h]h ]h"]h$]h&]uh1jhj @ubj)}(hhh]h)}(h:Support POSIX access control lists (ACLs). (EXT4_DEFM_ACL)h]h:Support POSIX access control lists (ACLs). (EXT4_DEFM_ACL)}(hj)@hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM hj&@ubah}(h]h ]h"]h$]h&]uh1jhj @ubeh}(h]h ]h"]h$]h&]uh1j{hjd?ubj|)}(hhh](j)}(hhh]h)}(h0x0010h]h0x0010}(hjI@hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM hjF@ubah}(h]h ]h"]h$]h&]uh1jhjC@ubj)}(hhh]h)}(h-Do not support 32-bit UIDs. (EXT4_DEFM_UID16)h]h-Do not support 32-bit UIDs. (EXT4_DEFM_UID16)}(hj`@hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM hj]@ubah}(h]h ]h"]h$]h&]uh1jhjC@ubeh}(h]h ]h"]h$]h&]uh1j{hjd?ubj|)}(hhh](j)}(hhh]h)}(h0x0020h]h0x0020}(hj@hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj}@ubah}(h]h ]h"]h$]h&]uh1jhjz@ubj)}(hhh]h)}(hJAll data and metadata are committed to the journal. (EXT4_DEFM_JMODE_DATA)h]hJAll data and metadata are committed to the journal. (EXT4_DEFM_JMODE_DATA)}(hj@hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj@ubah}(h]h ]h"]h$]h&]uh1jhjz@ubeh}(h]h ]h"]h$]h&]uh1j{hjd?ubj|)}(hhh](j)}(hhh]h)}(h0x0040h]h0x0040}(hj@hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj@ubah}(h]h ]h"]h$]h&]uh1jhj@ubj)}(hhh]h)}(hhAll data are flushed to the disk before metadata are committed to the journal. (EXT4_DEFM_JMODE_ORDERED)h]hhAll data are flushed to the disk before metadata are committed to the journal. (EXT4_DEFM_JMODE_ORDERED)}(hj@hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj@ubah}(h]h ]h"]h$]h&]uh1jhj@ubeh}(h]h ]h"]h$]h&]uh1j{hjd?ubj|)}(hhh](j)}(hhh]h)}(h0x0060h]h0x0060}(hj@hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj@ubah}(h]h ]h"]h$]h&]uh1jhj@ubj)}(hhh]h)}(hpData ordering is not preserved; data may be written after the metadata has been written. (EXT4_DEFM_JMODE_WBACK)h]hpData ordering is not preserved; data may be written after the metadata has been written. (EXT4_DEFM_JMODE_WBACK)}(hjAhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhjAubah}(h]h ]h"]h$]h&]uh1jhj@ubeh}(h]h ]h"]h$]h&]uh1j{hjd?ubj|)}(hhh](j)}(hhh]h)}(h0x0100h]h0x0100}(hj%AhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj"Aubah}(h]h ]h"]h$]h&]uh1jhjAubj)}(hhh]h)}(h,Disable write flushes. (EXT4_DEFM_NOBARRIER)h]h,Disable write flushes. (EXT4_DEFM_NOBARRIER)}(hjBubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKHuh1jOhj>Bubjw)}(hhh]j|)}(hhh](j)}(hhh]h)}(hValueh]hValue}(hj\BhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM+hjYBubah}(h]h ]h"]h$]h&]uh1jhjVBubj)}(hhh]h)}(h Descriptionh]h Description}(hjsBhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM,hjpBubah}(h]h ]h"]h$]h&]uh1jhjVBubeh}(h]h ]h"]h$]h&]uh1j{hjSBubah}(h]h ]h"]h$]h&]uh1jvhj>Bubj)}(hhh](j|)}(hhh](j)}(hhh]h)}(h0x0001h]h0x0001}(hjBhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM-hjBubah}(h]h ]h"]h$]h&]uh1jhjBubj)}(hhh]h)}(hSigned directory hash in use.h]hSigned directory hash in use.}(hjBhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM.hjBubah}(h]h ]h"]h$]h&]uh1jhjBubeh}(h]h ]h"]h$]h&]uh1j{hjBubj|)}(hhh](j)}(hhh]h)}(h0x0002h]h0x0002}(hjBhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM/hjBubah}(h]h ]h"]h$]h&]uh1jhjBubj)}(hhh]h)}(hUnsigned directory hash in use.h]hUnsigned directory hash in use.}(hjBhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM0hjBubah}(h]h ]h"]h$]h&]uh1jhjBubeh}(h]h ]h"]h$]h&]uh1j{hjBubj|)}(hhh](j)}(hhh]h)}(h0x0004h]h0x0004}(hj ChhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM1hjCubah}(h]h ]h"]h$]h&]uh1jhjCubj)}(hhh]h)}(hTo test development code.h]hTo test development code.}(hj!ChhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM2hjCubah}(h]h ]h"]h$]h&]uh1jhjCubeh}(h]h ]h"]h$]h&]uh1j{hjBubeh}(h]h ]h"]h$]h&]uh1jhj>Bubeh}(h]h ]h"]h$]h&]colsKuh1jJhj;Bubah}(h]h ]j,ah"]h$]h&]uh1jEhhhhhNhNubj-)}(h.. _super_encrypt:h]h}(h]h ]h"]h$]h&]jj>&uh1j-hM>hhhhhhj-Kubh)}(h>The ``s_encrypt_algos`` list can contain any of the following:h](hThe }(hjXChhhNhNubj,)}(h``s_encrypt_algos``h]hs_encrypt_algos}(hj`ChhhNhNubah}(h]h ]h"]h$]h&]uh1j+hjXCubh' list can contain any of the following:}(hjXChhhNhNubeh}(h]j>&ah ]h"] super_encryptah$]h&]uh1hhhhM6hhhhj-}jvCjNCsj -}j>&jNCsj-KubjF)}(hhh]jK)}(hhh](jP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhj~CubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKHuh1jOhj~Cubjw)}(hhh]j|)}(hhh](j)}(hhh]h)}(hValueh]hValue}(hjChhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM<hjCubah}(h]h ]h"]h$]h&]uh1jhjCubj)}(hhh]h)}(h Descriptionh]h Description}(hjChhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM=hjCubah}(h]h ]h"]h$]h&]uh1jhjCubeh}(h]h ]h"]h$]h&]uh1j{hjCubah}(h]h ]h"]h$]h&]uh1jvhj~Cubj)}(hhh](j|)}(hhh](j)}(hhh]h)}(hj/h]h0}(hjChhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM>hjCubah}(h]h ]h"]h$]h&]uh1jhjCubj)}(hhh]h)}(h,Invalid algorithm (ENCRYPTION_MODE_INVALID).h]h,Invalid algorithm (ENCRYPTION_MODE_INVALID).}(hjChhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM?hjCubah}(h]h ]h"]h$]h&]uh1jhjCubeh}(h]h ]h"]h$]h&]uh1j{hjCubj|)}(hhh](j)}(hhh]h)}(hj.h]h1}(hjDhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM@hjDubah}(h]h ]h"]h$]h&]uh1jhj Dubj)}(hhh]h)}(h6256-bit AES in XTS mode (ENCRYPTION_MODE_AES_256_XTS).h]h6256-bit AES in XTS mode (ENCRYPTION_MODE_AES_256_XTS).}(hj(DhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMAhj%Dubah}(h]h ]h"]h$]h&]uh1jhj Dubeh}(h]h ]h"]h$]h&]uh1j{hjCubj|)}(hhh](j)}(hhh]h)}(hj.h]h2}(hjHDhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMBhjEDubah}(h]h ]h"]h$]h&]uh1jhjBDubj)}(hhh]h)}(h6256-bit AES in GCM mode (ENCRYPTION_MODE_AES_256_GCM).h]h6256-bit AES in GCM mode (ENCRYPTION_MODE_AES_256_GCM).}(hj^DhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMChj[Dubah}(h]h ]h"]h$]h&]uh1jhjBDubeh}(h]h ]h"]h$]h&]uh1j{hjCubj|)}(hhh](j)}(hhh]h)}(hj!/h]h3}(hj~DhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMDhj{Dubah}(h]h ]h"]h$]h&]uh1jhjxDubj)}(hhh]h)}(h6256-bit AES in CBC mode (ENCRYPTION_MODE_AES_256_CBC).h]h6256-bit AES in CBC mode (ENCRYPTION_MODE_AES_256_CBC).}(hjDhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMEhjDubah}(h]h ]h"]h$]h&]uh1jhjxDubeh}(h]h ]h"]h$]h&]uh1j{hjCubeh}(h]h ]h"]h$]h&]uh1jhj~Cubeh}(h]h ]h"]h$]h&]colsKuh1jJhj{Cubah}(h]h ]j,ah"]h$]h&]uh1jEhhhhhNhNubh)}(h+Total size of the superblock is 1024 bytes.h]h+Total size of the superblock is 1024 bytes.}(hjDhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMGhhhhubh)}(h SPDX-License-Identifier: GPL-2.0h]h SPDX-License-Identifier: GPL-2.0}hjDsbah}(h]h ]h"]h$]h&]hhuh1hhhhhh.Documentation/filesystems/ext4/group_descr.rsthKubeh}(h] super-blockah ]h"]h$] super blockah&]uh1hhhhhhhhKj-Kubh)}(hhh](h)}(hBlock Group Descriptorsh]hBlock Group Descriptors}(hjDhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhhhjDhKubh)}(hX_Each block group on the filesystem has one of these descriptors associated with it. As noted in the Layout section above, the group descriptors (if present) are the second item in the block group. The standard configuration is for each block group to contain a full copy of the block group descriptor table unless the sparse_super feature flag is set.h]hX_Each block group on the filesystem has one of these descriptors associated with it. As noted in the Layout section above, the group descriptors (if present) are the second item in the block group. The standard configuration is for each block group to contain a full copy of the block group descriptor table unless the sparse_super feature flag is set.}(hjDhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjDhhubh)}(hXNotice how the group descriptor records the location of both bitmaps and the inode table (i.e. they can float). This means that within a block group, the only data structures with fixed locations are the superblock and the group descriptor table. The flex_bg mechanism uses this property to group several block groups into a flex group and lay out all of the groups' bitmaps and inode tables into one long run in the first group of the flex group.h]hXNotice how the group descriptor records the location of both bitmaps and the inode table (i.e. they can float). This means that within a block group, the only data structures with fixed locations are the superblock and the group descriptor table. The flex_bg mechanism uses this property to group several block groups into a flex group and lay out all of the groups’ bitmaps and inode tables into one long run in the first group of the flex group.}(hjEhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhK hjDhhubh)}(hXIf the meta_bg feature flag is set, then several block groups are grouped together into a meta group. Note that in the meta_bg case, however, the first and last two block groups within the larger meta group contain only group descriptors for the groups inside the meta group.h]hXIf the meta_bg feature flag is set, then several block groups are grouped together into a meta group. Note that in the meta_bg case, however, the first and last two block groups within the larger meta group contain only group descriptors for the groups inside the meta group.}(hjEhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjDhhubh)}(hDflex_bg and meta_bg do not appear to be mutually exclusive features.h]hDflex_bg and meta_bg do not appear to be mutually exclusive features.}(hj!EhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjDhhubh)}(hX>In ext2, ext3, and ext4 (when the 64bit feature is not enabled), the block group descriptor was only 32 bytes long and therefore ends at bg_checksum. On an ext4 filesystem with the 64bit feature enabled, the block group descriptor expands to at least the 64 bytes described below; the size is stored in the superblock.h]hX>In ext2, ext3, and ext4 (when the 64bit feature is not enabled), the block group descriptor was only 32 bytes long and therefore ends at bg_checksum. On an ext4 filesystem with the 64bit feature enabled, the block group descriptor expands to at least the 64 bytes described below; the size is stored in the superblock.}(hj/EhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjDhhubh)}(hXIf gdt_csum is set and metadata_csum is not set, the block group checksum is the crc16 of the FS UUID, the group number, and the group descriptor structure. If metadata_csum is set, then the block group checksum is the lower 16 bits of the checksum of the FS UUID, the group number, and the group descriptor structure. Both block and inode bitmap checksums are calculated against the FS UUID, the group number, and the entire bitmap.h]hXIf gdt_csum is set and metadata_csum is not set, the block group checksum is the crc16 of the FS UUID, the group number, and the group descriptor structure. If metadata_csum is set, then the block group checksum is the lower 16 bits of the checksum of the FS UUID, the group number, and the group descriptor structure. Both block and inode bitmap checksums are calculated against the FS UUID, the group number, and the entire bitmap.}(hj=EhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhK#hjDhhubh)}(hEThe block group descriptor is laid out in ``struct ext4_group_desc``.h](h*The block group descriptor is laid out in }(hjKEhhhNhNubj,)}(h``struct ext4_group_desc``h]hstruct ext4_group_desc}(hjSEhhhNhNubah}(h]h ]h"]h$]h&]uh1j+hjKEubh.}(hjKEhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhjDhK+hjDhhubjF)}(hhh]jK)}(hhh](jP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhjnEubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhjnEubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhjnEubjP)}(hhh]h}(h]h ]h"]h$]h&]jZK(uh1jOhjnEubjw)}(hhh]j|)}(hhh](j)}(hhh]h)}(hOffseth]hOffset}(hjEhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhK1hjEubah}(h]h ]h"]h$]h&]uh1jhjEubj)}(hhh]h)}(hSizeh]hSize}(hjEhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhK2hjEubah}(h]h ]h"]h$]h&]uh1jhjEubj)}(hhh]h)}(hNameh]hName}(hjEhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhK3hjEubah}(h]h ]h"]h$]h&]uh1jhjEubj)}(hhh]h)}(h Descriptionh]h Description}(hjEhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhK4hjEubah}(h]h ]h"]h$]h&]uh1jhjEubeh}(h]h ]h"]h$]h&]uh1j{hjEubah}(h]h ]h"]h$]h&]uh1jvhjnEubj)}(hhh](j|)}(hhh](j)}(hhh]h)}(h0x0h]h0x0}(hj FhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhK5hj Fubah}(h]h ]h"]h$]h&]uh1jhjFubj)}(hhh]h)}(h__le32h]h__le32}(hj#FhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhK6hj Fubah}(h]h ]h"]h$]h&]uh1jhjFubj)}(hhh]h)}(hbg_block_bitmap_loh]hbg_block_bitmap_lo}(hj:FhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhK7hj7Fubah}(h]h ]h"]h$]h&]uh1jhjFubj)}(hhh]h)}(h*Lower 32-bits of location of block bitmap.h]h*Lower 32-bits of location of block bitmap.}(hjQFhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhK8hjNFubah}(h]h ]h"]h$]h&]uh1jhjFubeh}(h]h ]h"]h$]h&]uh1j{hjFubj|)}(hhh](j)}(hhh]h)}(h0x4h]h0x4}(hjqFhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhK9hjnFubah}(h]h ]h"]h$]h&]uh1jhjkFubj)}(hhh]h)}(h__le32h]h__le32}(hjFhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhK:hjFubah}(h]h ]h"]h$]h&]uh1jhjkFubj)}(hhh]h)}(hbg_inode_bitmap_loh]hbg_inode_bitmap_lo}(hjFhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhK;hjFubah}(h]h ]h"]h$]h&]uh1jhjkFubj)}(hhh]h)}(h*Lower 32-bits of location of inode bitmap.h]h*Lower 32-bits of location of inode bitmap.}(hjFhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjFubah}(h]h ]h"]h$]h&]uh1jhjFubj)}(hhh]h)}(hbg_inode_table_loh]hbg_inode_table_lo}(hjGhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhK?hjGubah}(h]h ]h"]h$]h&]uh1jhjFubj)}(hhh]h)}(h)Lower 32-bits of location of inode table.h]h)Lower 32-bits of location of inode table.}(hjGhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhK@hjGubah}(h]h ]h"]h$]h&]uh1jhjFubeh}(h]h ]h"]h$]h&]uh1j{hjFubj|)}(hhh](j)}(hhh]h)}(h0xCh]h0xC}(hj;GhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKAhj8Gubah}(h]h ]h"]h$]h&]uh1jhj5Gubj)}(hhh]h)}(h__le16h]h__le16}(hjRGhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKBhjOGubah}(h]h ]h"]h$]h&]uh1jhj5Gubj)}(hhh]h)}(hbg_free_blocks_count_loh]hbg_free_blocks_count_lo}(hjiGhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKChjfGubah}(h]h ]h"]h$]h&]uh1jhj5Gubj)}(hhh]h)}(h"Lower 16-bits of free block count.h]h"Lower 16-bits of free block count.}(hjGhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKDhj}Gubah}(h]h ]h"]h$]h&]uh1jhj5Gubeh}(h]h ]h"]h$]h&]uh1j{hjFubj|)}(hhh](j)}(hhh]h)}(h0xEh]h0xE}(hjGhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKEhjGubah}(h]h ]h"]h$]h&]uh1jhjGubj)}(hhh]h)}(h__le16h]h__le16}(hjGhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKFhjGubah}(h]h ]h"]h$]h&]uh1jhjGubj)}(hhh]h)}(hbg_free_inodes_count_loh]hbg_free_inodes_count_lo}(hjGhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKGhjGubah}(h]h ]h"]h$]h&]uh1jhjGubj)}(hhh]h)}(h"Lower 16-bits of free inode count.h]h"Lower 16-bits of free inode count.}(hjGhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKHhjGubah}(h]h ]h"]h$]h&]uh1jhjGubeh}(h]h ]h"]h$]h&]uh1j{hjFubj|)}(hhh](j)}(hhh]h)}(h0x10h]h0x10}(hjHhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKIhjHubah}(h]h ]h"]h$]h&]uh1jhjGubj)}(hhh]h)}(h__le16h]h__le16}(hjHhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKJhjHubah}(h]h ]h"]h$]h&]uh1jhjGubj)}(hhh]h)}(hbg_used_dirs_count_loh]hbg_used_dirs_count_lo}(hj3HhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKKhj0Hubah}(h]h ]h"]h$]h&]uh1jhjGubj)}(hhh]h)}(h!Lower 16-bits of directory count.h]h!Lower 16-bits of directory count.}(hjJHhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKLhjGHubah}(h]h ]h"]h$]h&]uh1jhjGubeh}(h]h ]h"]h$]h&]uh1j{hjFubj|)}(hhh](j)}(hhh]h)}(h0x12h]h0x12}(hjjHhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKMhjgHubah}(h]h ]h"]h$]h&]uh1jhjdHubj)}(hhh]h)}(h__le16h]h__le16}(hjHhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKNhj~Hubah}(h]h ]h"]h$]h&]uh1jhjdHubj)}(hhh]h)}(hbg_flagsh]hbg_flags}(hjHhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKOhjHubah}(h]h ]h"]h$]h&]uh1jhjdHubj)}(hhh]h)}(h0Block group flags. See the bgflags_ table below.h](hBlock group flags. See the }(hjHhhhNhNubj)}(hbgflags_h]hbgflags}(hjHhhhNhNubah}(h]h ]h"]h$]h&]namebgflagsjbgflagsuh1jhjHjKubh table below.}(hjHhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhjDhKPhjHubah}(h]h ]h"]h$]h&]uh1jhjdHubeh}(h]h ]h"]h$]h&]uh1j{hjFubj|)}(hhh](j)}(hhh]h)}(h0x14h]h0x14}(hjHhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKQhjHubah}(h]h ]h"]h$]h&]uh1jhjHubj)}(hhh]h)}(h__le32h]h__le32}(hjHhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKRhjHubah}(h]h ]h"]h$]h&]uh1jhjHubj)}(hhh]h)}(hbg_exclude_bitmap_loh]hbg_exclude_bitmap_lo}(hjIhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKShjIubah}(h]h ]h"]h$]h&]uh1jhjHubj)}(hhh]h)}(h7Lower 32-bits of location of snapshot exclusion bitmap.h]h7Lower 32-bits of location of snapshot exclusion bitmap.}(hj)IhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKThj&Iubah}(h]h ]h"]h$]h&]uh1jhjHubeh}(h]h ]h"]h$]h&]uh1j{hjFubj|)}(hhh](j)}(hhh]h)}(h0x18h]h0x18}(hjIIhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKUhjFIubah}(h]h ]h"]h$]h&]uh1jhjCIubj)}(hhh]h)}(h__le16h]h__le16}(hj`IhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKVhj]Iubah}(h]h ]h"]h$]h&]uh1jhjCIubj)}(hhh]h)}(hbg_block_bitmap_csum_loh]hbg_block_bitmap_csum_lo}(hjwIhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKWhjtIubah}(h]h ]h"]h$]h&]uh1jhjCIubj)}(hhh]h)}(h+Lower 16-bits of the block bitmap checksum.h]h+Lower 16-bits of the block bitmap checksum.}(hjIhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKXhjIubah}(h]h ]h"]h$]h&]uh1jhjCIubeh}(h]h ]h"]h$]h&]uh1j{hjFubj|)}(hhh](j)}(hhh]h)}(h0x1Ah]h0x1A}(hjIhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKYhjIubah}(h]h ]h"]h$]h&]uh1jhjIubj)}(hhh]h)}(h__le16h]h__le16}(hjIhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKZhjIubah}(h]h ]h"]h$]h&]uh1jhjIubj)}(hhh]h)}(hbg_inode_bitmap_csum_loh]hbg_inode_bitmap_csum_lo}(hjIhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhK[hjIubah}(h]h ]h"]h$]h&]uh1jhjIubj)}(hhh]h)}(h+Lower 16-bits of the inode bitmap checksum.h]h+Lower 16-bits of the inode bitmap checksum.}(hjIhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhK\hjIubah}(h]h ]h"]h$]h&]uh1jhjIubeh}(h]h ]h"]h$]h&]uh1j{hjFubj|)}(hhh](j)}(hhh]h)}(h0x1Ch]h0x1C}(hjJhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhK]hjJubah}(h]h ]h"]h$]h&]uh1jhj Jubj)}(hhh]h)}(h__le16h]h__le16}(hj*JhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhK^hj'Jubah}(h]h ]h"]h$]h&]uh1jhj Jubj)}(hhh]h)}(hbg_itable_unused_loh]hbg_itable_unused_lo}(hjAJhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhK_hj>Jubah}(h]h ]h"]h$]h&]uh1jhj Jubj)}(hhh]h)}(hLower 16-bits of unused inode count. If set, we needn't scan past the ``(sb.s_inodes_per_group - gdt.bg_itable_unused)`` th entry in the inode table for this group.h](hHLower 16-bits of unused inode count. If set, we needn’t scan past the }(hjXJhhhNhNubj,)}(h2``(sb.s_inodes_per_group - gdt.bg_itable_unused)``h]h.(sb.s_inodes_per_group - gdt.bg_itable_unused)}(hj`JhhhNhNubah}(h]h ]h"]h$]h&]uh1j+hjXJubh, th entry in the inode table for this group.}(hjXJhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhjDhK`hjUJubah}(h]h ]h"]h$]h&]uh1jhj Jubeh}(h]h ]h"]h$]h&]uh1j{hjFubj|)}(hhh](j)}(hhh]h)}(h0x1Eh]h0x1E}(hjJhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKchjJubah}(h]h ]h"]h$]h&]uh1jhjJubj)}(hhh]h)}(h__le16h]h__le16}(hjJhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKdhjJubah}(h]h ]h"]h$]h&]uh1jhjJubj)}(hhh]h)}(h bg_checksumh]h bg_checksum}(hjJhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKehjJubah}(h]h ]h"]h$]h&]uh1jhjJubj)}(hhh]h)}(hX<Group descriptor checksum; crc16(sb_uuid+group_num+bg_desc) if the RO_COMPAT_GDT_CSUM feature is set, or crc32c(sb_uuid+group_num+bg_desc) & 0xFFFF if the RO_COMPAT_METADATA_CSUM feature is set. The bg_checksum field in bg_desc is skipped when calculating crc16 checksum, and set to zero if crc32c checksum is used.h]hX<Group descriptor checksum; crc16(sb_uuid+group_num+bg_desc) if the RO_COMPAT_GDT_CSUM feature is set, or crc32c(sb_uuid+group_num+bg_desc) & 0xFFFF if the RO_COMPAT_METADATA_CSUM feature is set. The bg_checksum field in bg_desc is skipped when calculating crc16 checksum, and set to zero if crc32c checksum is used.}(hjJhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKfhjJubah}(h]h ]h"]h$]h&]uh1jhjJubeh}(h]h ]h"]h$]h&]uh1j{hjFubj|)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]uh1jhjJubj)}(hhh]h}(h]h ]h"]h$]h&]uh1jhjJubj)}(hhh]h}(h]h ]h"]h$]h&]uh1jhjJubj)}(hhh]h)}(hMThese fields only exist if the 64bit feature is enabled and s_desc_size > 32.h]hMThese fields only exist if the 64bit feature is enabled and s_desc_size > 32.}(hj KhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKohjKubah}(h]h ]h"]h$]h&]uh1jhjJubeh}(h]h ]h"]h$]h&]uh1j{hjFubj|)}(hhh](j)}(hhh]h)}(h0x20h]h0x20}(hj*KhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKqhj'Kubah}(h]h ]h"]h$]h&]uh1jhj$Kubj)}(hhh]h)}(h__le32h]h__le32}(hjAKhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKrhj>Kubah}(h]h ]h"]h$]h&]uh1jhj$Kubj)}(hhh]h)}(hbg_block_bitmap_hih]hbg_block_bitmap_hi}(hjXKhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKshjUKubah}(h]h ]h"]h$]h&]uh1jhj$Kubj)}(hhh]h)}(h*Upper 32-bits of location of block bitmap.h]h*Upper 32-bits of location of block bitmap.}(hjoKhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKthjlKubah}(h]h ]h"]h$]h&]uh1jhj$Kubeh}(h]h ]h"]h$]h&]uh1j{hjFubj|)}(hhh](j)}(hhh]h)}(h0x24h]h0x24}(hjKhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKuhjKubah}(h]h ]h"]h$]h&]uh1jhjKubj)}(hhh]h)}(h__le32h]h__le32}(hjKhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKvhjKubah}(h]h ]h"]h$]h&]uh1jhjKubj)}(hhh]h)}(hbg_inode_bitmap_hih]hbg_inode_bitmap_hi}(hjKhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKwhjKubah}(h]h ]h"]h$]h&]uh1jhjKubj)}(hhh]h)}(h+Upper 32-bits of location of inodes bitmap.h]h+Upper 32-bits of location of inodes bitmap.}(hjKhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKxhjKubah}(h]h ]h"]h$]h&]uh1jhjKubeh}(h]h ]h"]h$]h&]uh1j{hjFubj|)}(hhh](j)}(hhh]h)}(h0x28h]h0x28}(hjKhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKyhjKubah}(h]h ]h"]h$]h&]uh1jhjKubj)}(hhh]h)}(h__le32h]h__le32}(hj LhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKzhjLubah}(h]h ]h"]h$]h&]uh1jhjKubj)}(hhh]h)}(hbg_inode_table_hih]hbg_inode_table_hi}(hj"LhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhK{hjLubah}(h]h ]h"]h$]h&]uh1jhjKubj)}(hhh]h)}(h*Upper 32-bits of location of inodes table.h]h*Upper 32-bits of location of inodes table.}(hj9LhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhK|hj6Lubah}(h]h ]h"]h$]h&]uh1jhjKubeh}(h]h ]h"]h$]h&]uh1j{hjFubj|)}(hhh](j)}(hhh]h)}(h0x2Ch]h0x2C}(hjYLhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhK}hjVLubah}(h]h ]h"]h$]h&]uh1jhjSLubj)}(hhh]h)}(h__le16h]h__le16}(hjpLhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhK~hjmLubah}(h]h ]h"]h$]h&]uh1jhjSLubj)}(hhh]h)}(hbg_free_blocks_count_hih]hbg_free_blocks_count_hi}(hjLhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjLubah}(h]h ]h"]h$]h&]uh1jhjSLubj)}(hhh]h)}(h"Upper 16-bits of free block count.h]h"Upper 16-bits of free block count.}(hjLhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjLubah}(h]h ]h"]h$]h&]uh1jhjSLubeh}(h]h ]h"]h$]h&]uh1j{hjFubj|)}(hhh](j)}(hhh]h)}(h0x2Eh]h0x2E}(hjLhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjLubah}(h]h ]h"]h$]h&]uh1jhjLubj)}(hhh]h)}(h__le16h]h__le16}(hjLhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjLubah}(h]h ]h"]h$]h&]uh1jhjLubj)}(hhh]h)}(hbg_free_inodes_count_hih]hbg_free_inodes_count_hi}(hjLhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjLubah}(h]h ]h"]h$]h&]uh1jhjLubj)}(hhh]h)}(h"Upper 16-bits of free inode count.h]h"Upper 16-bits of free inode count.}(hjMhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjMubah}(h]h ]h"]h$]h&]uh1jhjLubeh}(h]h ]h"]h$]h&]uh1j{hjFubj|)}(hhh](j)}(hhh]h)}(h0x30h]h0x30}(hj#MhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhj Mubah}(h]h ]h"]h$]h&]uh1jhjMubj)}(hhh]h)}(h__le16h]h__le16}(hj:MhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhj7Mubah}(h]h ]h"]h$]h&]uh1jhjMubj)}(hhh]h)}(hbg_used_dirs_count_hih]hbg_used_dirs_count_hi}(hjQMhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjNMubah}(h]h ]h"]h$]h&]uh1jhjMubj)}(hhh]h)}(h!Upper 16-bits of directory count.h]h!Upper 16-bits of directory count.}(hjhMhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjeMubah}(h]h ]h"]h$]h&]uh1jhjMubeh}(h]h ]h"]h$]h&]uh1j{hjFubj|)}(hhh](j)}(hhh]h)}(h0x32h]h0x32}(hjMhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjMubah}(h]h ]h"]h$]h&]uh1jhjMubj)}(hhh]h)}(h__le16h]h__le16}(hjMhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjMubah}(h]h ]h"]h$]h&]uh1jhjMubj)}(hhh]h)}(hbg_itable_unused_hih]hbg_itable_unused_hi}(hjMhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjMubah}(h]h ]h"]h$]h&]uh1jhjMubj)}(hhh]h)}(h$Upper 16-bits of unused inode count.h]h$Upper 16-bits of unused inode count.}(hjMhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjMubah}(h]h ]h"]h$]h&]uh1jhjMubeh}(h]h ]h"]h$]h&]uh1j{hjFubj|)}(hhh](j)}(hhh]h)}(h0x34h]h0x34}(hjMhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjMubah}(h]h ]h"]h$]h&]uh1jhjMubj)}(hhh]h)}(h__le32h]h__le32}(hjNhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjNubah}(h]h ]h"]h$]h&]uh1jhjMubj)}(hhh]h)}(hbg_exclude_bitmap_hih]hbg_exclude_bitmap_hi}(hjNhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjNubah}(h]h ]h"]h$]h&]uh1jhjMubj)}(hhh]h)}(h7Upper 32-bits of location of snapshot exclusion bitmap.h]h7Upper 32-bits of location of snapshot exclusion bitmap.}(hj2NhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhj/Nubah}(h]h ]h"]h$]h&]uh1jhjMubeh}(h]h ]h"]h$]h&]uh1j{hjFubj|)}(hhh](j)}(hhh]h)}(h0x38h]h0x38}(hjRNhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjONubah}(h]h ]h"]h$]h&]uh1jhjLNubj)}(hhh]h)}(h__le16h]h__le16}(hjiNhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjfNubah}(h]h ]h"]h$]h&]uh1jhjLNubj)}(hhh]h)}(hbg_block_bitmap_csum_hih]hbg_block_bitmap_csum_hi}(hjNhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhj}Nubah}(h]h ]h"]h$]h&]uh1jhjLNubj)}(hhh]h)}(h+Upper 16-bits of the block bitmap checksum.h]h+Upper 16-bits of the block bitmap checksum.}(hjNhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjNubah}(h]h ]h"]h$]h&]uh1jhjLNubeh}(h]h ]h"]h$]h&]uh1j{hjFubj|)}(hhh](j)}(hhh]h)}(h0x3Ah]h0x3A}(hjNhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjNubah}(h]h ]h"]h$]h&]uh1jhjNubj)}(hhh]h)}(h__le16h]h__le16}(hjNhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjNubah}(h]h ]h"]h$]h&]uh1jhjNubj)}(hhh]h)}(hbg_inode_bitmap_csum_hih]hbg_inode_bitmap_csum_hi}(hjNhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjNubah}(h]h ]h"]h$]h&]uh1jhjNubj)}(hhh]h)}(h+Upper 16-bits of the inode bitmap checksum.h]h+Upper 16-bits of the inode bitmap checksum.}(hjNhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjNubah}(h]h ]h"]h$]h&]uh1jhjNubeh}(h]h ]h"]h$]h&]uh1j{hjFubj|)}(hhh](j)}(hhh]h)}(h0x3Ch]h0x3C}(hjOhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjOubah}(h]h ]h"]h$]h&]uh1jhjOubj)}(hhh]h)}(h__u32h]h__u32}(hj3OhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhj0Oubah}(h]h ]h"]h$]h&]uh1jhjOubj)}(hhh]h)}(h bg_reservedh]h bg_reserved}(hjJOhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjGOubah}(h]h ]h"]h$]h&]uh1jhjOubj)}(hhh]h)}(hPadding to 64 bytes.h]hPadding to 64 bytes.}(hjaOhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhj^Oubah}(h]h ]h"]h$]h&]uh1jhjOubeh}(h]h ]h"]h$]h&]uh1j{hjFubeh}(h]h ]h"]h$]h&]uh1jhjnEubeh}(h]h ]h"]h$]h&]colsKuh1jJhjkEubah}(h]h ]j,ah"]h$]h&]uh1jEhjDhhhNhNubj-)}(h .. _bgflags:h]h}(h]h ]h"]h$]h&]jjHuh1j-hMhjDhhhjDj-Kubh)}(h:Block group flags can be any combination of the following:h]h:Block group flags can be any combination of the following:}(hjOhhhNhNubah}(h]jHah ]h"]bgflagsah$]h&]uh1hhjDhKhjDhhj-}jOjOsj -}jHjOsj-KubjF)}(hhh]jK)}(hhh](jP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhjOubjP)}(hhh]h}(h]h ]h"]h$]h&]jZK@uh1jOhjOubjw)}(hhh]j|)}(hhh](j)}(hhh]h)}(hValueh]hValue}(hjOhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjOubah}(h]h ]h"]h$]h&]uh1jhjOubj)}(hhh]h)}(h Descriptionh]h Description}(hjOhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjOubah}(h]h ]h"]h$]h&]uh1jhjOubeh}(h]h ]h"]h$]h&]uh1j{hjOubah}(h]h ]h"]h$]h&]uh1jvhjOubj)}(hhh](j|)}(hhh](j)}(hhh]h)}(h0x1h]h0x1}(hj PhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjPubah}(h]h ]h"]h$]h&]uh1jhjPubj)}(hhh]h)}(hBinode table and bitmap are not initialized (EXT4_BG_INODE_UNINIT).h]hBinode table and bitmap are not initialized (EXT4_BG_INODE_UNINIT).}(hj!PhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjPubah}(h]h ]h"]h$]h&]uh1jhjPubeh}(h]h ]h"]h$]h&]uh1j{hjPubj|)}(hhh](j)}(hhh]h)}(h0x2h]h0x2}(hjAPhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhj>Pubah}(h]h ]h"]h$]h&]uh1jhj;Pubj)}(hhh]h)}(h7block bitmap is not initialized (EXT4_BG_BLOCK_UNINIT).h]h7block bitmap is not initialized (EXT4_BG_BLOCK_UNINIT).}(hjXPhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjUPubah}(h]h ]h"]h$]h&]uh1jhj;Pubeh}(h]h ]h"]h$]h&]uh1j{hjPubj|)}(hhh](j)}(hhh]h)}(h0x4h]h0x4}(hjxPhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjuPubah}(h]h ]h"]h$]h&]uh1jhjrPubj)}(hhh]h)}(h-inode table is zeroed (EXT4_BG_INODE_ZEROED).h]h-inode table is zeroed (EXT4_BG_INODE_ZEROED).}(hjPhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjDhKhjPubah}(h]h ]h"]h$]h&]uh1jhjrPubeh}(h]h ]h"]h$]h&]uh1j{hjPubeh}(h]h ]h"]h$]h&]uh1jhjOubeh}(h]h ]h"]h$]h&]colsKuh1jJhjOubah}(h]h ]j,ah"]h$]h&]uh1jEhjDhhhNhNubh)}(h SPDX-License-Identifier: GPL-2.0h]h SPDX-License-Identifier: GPL-2.0}hjPsbah}(h]h ]h"]h$]h&]hhuh1hhjDhhh*Documentation/filesystems/ext4/bitmaps.rsthKubeh}(h]block-group-descriptorsah ]h"]block group descriptorsah$]h&]uh1hhhhhhjDhKubh)}(hhh](h)}(hBlock and inode Bitmapsh]hBlock and inode Bitmaps}(hjPhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjPhhhjPhKubh)}(hMThe data block bitmap tracks the usage of data blocks within the block group.h]hMThe data block bitmap tracks the usage of data blocks within the block group.}(hjPhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjPhKhjPhhubh)}(hEThe inode bitmap records which entries in the inode table are in use.h]hEThe inode bitmap records which entries in the inode table are in use.}(hjPhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjPhK hjPhhubh)}(hAs with most bitmaps, one bit represents the usage status of one data block or inode table entry. This implies a block group size of 8 * number_of_bytes_in_a_logical_block.h]hAs with most bitmaps, one bit represents the usage status of one data block or inode table entry. This implies a block group size of 8 * number_of_bytes_in_a_logical_block.}(hjQhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjPhK hjPhhubh)}(hXNOTE: If ``BLOCK_UNINIT`` is set for a given block group, various parts of the kernel and e2fsprogs code pretends that the block bitmap contains zeros (i.e. all blocks in the group are free). However, it is not necessarily the case that no blocks are in use -- if ``meta_bg`` is set, the bitmaps and group descriptor live inside the group. Unfortunately, ext2fs_test_block_bitmap2() will return '0' for those locations, which produces confusing debugfs output.h](h NOTE: If }(hjQhhhNhNubj,)}(h``BLOCK_UNINIT``h]h BLOCK_UNINIT}(hjQhhhNhNubah}(h]h ]h"]h$]h&]uh1j+hjQubh is set for a given block group, various parts of the kernel and e2fsprogs code pretends that the block bitmap contains zeros (i.e. all blocks in the group are free). However, it is not necessarily the case that no blocks are in use -- if }(hjQhhhNhNubj,)}(h ``meta_bg``h]hmeta_bg}(hj(QhhhNhNubah}(h]h ]h"]h$]h&]uh1j+hjQubh is set, the bitmaps and group descriptor live inside the group. Unfortunately, ext2fs_test_block_bitmap2() will return ‘0’ for those locations, which produces confusing debugfs output.}(hjQhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhjPhKhjPhhubeh}(h]block-and-inode-bitmapsah ]h"]block and inode bitmapsah$]h&]uh1hhhhhhjPhKubh)}(hhh](h)}(h Inode Tableh]h Inode Table}(hjKQhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjHQhhhjPhKubh)}(hInode tables are statically allocated at mkfs time. Each block group descriptor points to the start of the table, and the superblock records the number of inodes per group. See the section on inodes for more information.h]hInode tables are statically allocated at mkfs time. Each block group descriptor points to the start of the table, and the superblock records the number of inodes per group. See the section on inodes for more information.}(hjYQhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjPhKhjHQhhubh)}(h SPDX-License-Identifier: GPL-2.0h]h SPDX-License-Identifier: GPL-2.0}hjgQsbah}(h]h ]h"]h$]h&]hhuh1hhjHQhhh&Documentation/filesystems/ext4/mmp.rsthKubeh}(h] inode-tableah ]h"] inode tableah$]h&]uh1hhhhhhjPhKubh)}(hhh](h)}(hMultiple Mount Protectionh]hMultiple Mount Protection}(hjQhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj~QhhhjuQhKubh)}(hX&Multiple mount protection (MMP) is a feature that protects the filesystem against multiple hosts trying to use the filesystem simultaneously. When a filesystem is opened (for mounting, or fsck, etc.), the MMP code running on the node (call it node A) checks a sequence number. If the sequence number is EXT4_MMP_SEQ_CLEAN, the open continues. If the sequence number is EXT4_MMP_SEQ_FSCK, then fsck is (hopefully) running, and open fails immediately. Otherwise, the open code will wait for twice the specified MMP check interval and check the sequence number again. If the sequence number has changed, then the filesystem is active on another machine and the open fails. If the MMP code passes all of those checks, a new MMP sequence number is generated and written to the MMP block, and the mount proceeds.h]hX&Multiple mount protection (MMP) is a feature that protects the filesystem against multiple hosts trying to use the filesystem simultaneously. When a filesystem is opened (for mounting, or fsck, etc.), the MMP code running on the node (call it node A) checks a sequence number. If the sequence number is EXT4_MMP_SEQ_CLEAN, the open continues. If the sequence number is EXT4_MMP_SEQ_FSCK, then fsck is (hopefully) running, and open fails immediately. Otherwise, the open code will wait for twice the specified MMP check interval and check the sequence number again. If the sequence number has changed, then the filesystem is active on another machine and the open fails. If the MMP code passes all of those checks, a new MMP sequence number is generated and written to the MMP block, and the mount proceeds.}(hjQhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhKhj~Qhhubh)}(hXWhile the filesystem is live, the kernel sets up a timer to re-check the MMP block at the specified MMP check interval. To perform the re-check, the MMP sequence number is re-read; if it does not match the in-memory MMP sequence number, then another node (node B) has mounted the filesystem, and node A remounts the filesystem read-only. If the sequence numbers match, the sequence number is incremented both in memory and on disk, and the re-check is complete.h]hXWhile the filesystem is live, the kernel sets up a timer to re-check the MMP block at the specified MMP check interval. To perform the re-check, the MMP sequence number is re-read; if it does not match the in-memory MMP sequence number, then another node (node B) has mounted the filesystem, and node A remounts the filesystem read-only. If the sequence numbers match, the sequence number is incremented both in memory and on disk, and the re-check is complete.}(hjQhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhKhj~Qhhubh)}(hThe hostname and device filename are written into the MMP block whenever an open operation succeeds. The MMP code does not use these values; they are provided purely for informational purposes.h]hThe hostname and device filename are written into the MMP block whenever an open operation succeeds. The MMP code does not use these values; they are provided purely for informational purposes.}(hjQhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhKhj~Qhhubh)}(h~The checksum is calculated against the FS UUID and the MMP structure. The MMP structure (``struct mmp_struct``) is as follows:h](hYThe checksum is calculated against the FS UUID and the MMP structure. The MMP structure (}(hjQhhhNhNubj,)}(h``struct mmp_struct``h]hstruct mmp_struct}(hjQhhhNhNubah}(h]h ]h"]h$]h&]uh1j+hjQubh) is as follows:}(hjQhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhjuQhKhj~QhhubjF)}(hhh]jK)}(hhh](jP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhjQubjP)}(hhh]h}(h]h ]h"]h$]h&]jZK uh1jOhjQubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhjQubjP)}(hhh]h}(h]h ]h"]h$]h&]jZK(uh1jOhjQubjw)}(hhh]j|)}(hhh](j)}(hhh]h)}(hOffseth]hOffset}(hj RhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhK&hj Rubah}(h]h ]h"]h$]h&]uh1jhjRubj)}(hhh]h)}(hTypeh]hType}(hj#RhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhK'hj Rubah}(h]h ]h"]h$]h&]uh1jhjRubj)}(hhh]h)}(hNameh]hName}(hj:RhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhK(hj7Rubah}(h]h ]h"]h$]h&]uh1jhjRubj)}(hhh]h)}(h Descriptionh]h Description}(hjQRhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhK)hjNRubah}(h]h ]h"]h$]h&]uh1jhjRubeh}(h]h ]h"]h$]h&]uh1j{hjRubah}(h]h ]h"]h$]h&]uh1jvhjQubj)}(hhh](j|)}(hhh](j)}(hhh]h)}(h0x0h]h0x0}(hjzRhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhK*hjwRubah}(h]h ]h"]h$]h&]uh1jhjtRubj)}(hhh]h)}(h__le32h]h__le32}(hjRhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhK+hjRubah}(h]h ]h"]h$]h&]uh1jhjtRubj)}(hhh]h)}(h mmp_magich]h mmp_magic}(hjRhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhK,hjRubah}(h]h ]h"]h$]h&]uh1jhjtRubj)}(hhh]h)}(h-Magic number for MMP, 0x004D4D50 (“MMP”).h]h-Magic number for MMP, 0x004D4D50 (“MMP”).}(hjRhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhK-hjRubah}(h]h ]h"]h$]h&]uh1jhjtRubeh}(h]h ]h"]h$]h&]uh1j{hjqRubj|)}(hhh](j)}(hhh]h)}(h0x4h]h0x4}(hjRhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhK.hjRubah}(h]h ]h"]h$]h&]uh1jhjRubj)}(hhh]h)}(h__le32h]h__le32}(hjRhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhK/hjRubah}(h]h ]h"]h$]h&]uh1jhjRubj)}(hhh]h)}(hmmp_seqh]hmmp_seq}(hj ShhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhK0hj Subah}(h]h ]h"]h$]h&]uh1jhjRubj)}(hhh]h)}(h&Sequence number, updated periodically.h]h&Sequence number, updated periodically.}(hj$ShhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhK1hj!Subah}(h]h ]h"]h$]h&]uh1jhjRubeh}(h]h ]h"]h$]h&]uh1j{hjqRubj|)}(hhh](j)}(hhh]h)}(h0x8h]h0x8}(hjDShhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhK2hjASubah}(h]h ]h"]h$]h&]uh1jhj>Subj)}(hhh]h)}(h__le64h]h__le64}(hj[ShhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhK3hjXSubah}(h]h ]h"]h$]h&]uh1jhj>Subj)}(hhh]h)}(hmmp_timeh]hmmp_time}(hjrShhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhK4hjoSubah}(h]h ]h"]h$]h&]uh1jhj>Subj)}(hhh]h)}(h)Time that the MMP block was last updated.h]h)Time that the MMP block was last updated.}(hjShhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhK5hjSubah}(h]h ]h"]h$]h&]uh1jhj>Subeh}(h]h ]h"]h$]h&]uh1j{hjqRubj|)}(hhh](j)}(hhh]h)}(h0x10h]h0x10}(hjShhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhK6hjSubah}(h]h ]h"]h$]h&]uh1jhjSubj)}(hhh]h)}(hchar[64]h]hchar[64]}(hjShhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhK7hjSubah}(h]h ]h"]h$]h&]uh1jhjSubj)}(hhh]h)}(h mmp_nodenameh]h mmp_nodename}(hjShhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhK8hjSubah}(h]h ]h"]h$]h&]uh1jhjSubj)}(hhh]h)}(h0Hostname of the node that opened the filesystem.h]h0Hostname of the node that opened the filesystem.}(hjShhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhK9hjSubah}(h]h ]h"]h$]h&]uh1jhjSubeh}(h]h ]h"]h$]h&]uh1j{hjqRubj|)}(hhh](j)}(hhh]h)}(h0x50h]h0x50}(hjThhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhK:hj Tubah}(h]h ]h"]h$]h&]uh1jhjTubj)}(hhh]h)}(hchar[32]h]hchar[32]}(hj%ThhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhK;hj"Tubah}(h]h ]h"]h$]h&]uh1jhjTubj)}(hhh]h)}(h mmp_bdevnameh]h mmp_bdevname}(hjhjpTubah}(h]h ]h"]h$]h&]uh1jhjmTubj)}(hhh]h)}(h__le16h]h__le16}(hjThhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhK?hjTubah}(h]h ]h"]h$]h&]uh1jhjmTubj)}(hhh]h)}(hmmp_check_intervalh]hmmp_check_interval}(hjThhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhK@hjTubah}(h]h ]h"]h$]h&]uh1jhjmTubj)}(hhh]h)}(h&The MMP re-check interval, in seconds.h]h&The MMP re-check interval, in seconds.}(hjThhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhKAhjTubah}(h]h ]h"]h$]h&]uh1jhjmTubeh}(h]h ]h"]h$]h&]uh1j{hjqRubj|)}(hhh](j)}(hhh]h)}(h0x72h]h0x72}(hjThhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhKBhjTubah}(h]h ]h"]h$]h&]uh1jhjTubj)}(hhh]h)}(h__le16h]h__le16}(hjThhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhKChjTubah}(h]h ]h"]h$]h&]uh1jhjTubj)}(hhh]h)}(hmmp_pad1h]hmmp_pad1}(hjUhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhKDhjUubah}(h]h ]h"]h$]h&]uh1jhjTubj)}(hhh]h)}(hZero.h]hZero.}(hjUhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhKEhjUubah}(h]h ]h"]h$]h&]uh1jhjTubeh}(h]h ]h"]h$]h&]uh1j{hjqRubj|)}(hhh](j)}(hhh]h)}(h0x74h]h0x74}(hj=UhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhKFhj:Uubah}(h]h ]h"]h$]h&]uh1jhj7Uubj)}(hhh]h)}(h __le32[226]h]h __le32[226]}(hjTUhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhKGhjQUubah}(h]h ]h"]h$]h&]uh1jhj7Uubj)}(hhh]h)}(hmmp_pad2h]hmmp_pad2}(hjkUhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhKHhjhUubah}(h]h ]h"]h$]h&]uh1jhj7Uubj)}(hhh]h)}(hZero.h]hZero.}(hjUhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhKIhjUubah}(h]h ]h"]h$]h&]uh1jhj7Uubeh}(h]h ]h"]h$]h&]uh1j{hjqRubj|)}(hhh](j)}(hhh]h)}(h0x3FCh]h0x3FC}(hjUhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhKJhjUubah}(h]h ]h"]h$]h&]uh1jhjUubj)}(hhh]h)}(h__le32h]h__le32}(hjUhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhKKhjUubah}(h]h ]h"]h$]h&]uh1jhjUubj)}(hhh]h)}(h mmp_checksumh]h mmp_checksum}(hjUhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhKLhjUubah}(h]h ]h"]h$]h&]uh1jhjUubj)}(hhh]h)}(hChecksum of the MMP block.h]hChecksum of the MMP block.}(hjUhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjuQhKMhjUubah}(h]h ]h"]h$]h&]uh1jhjUubeh}(h]h ]h"]h$]h&]uh1j{hjqRubeh}(h]h ]h"]h$]h&]uh1jhjQubeh}(h]h ]h"]h$]h&]colsKuh1jJhjQubah}(h]h ]j,ah"]h$]h&]uh1jEhj~QhhhNhNubh)}(h SPDX-License-Identifier: GPL-2.0h]h SPDX-License-Identifier: GPL-2.0}hjVsbah}(h]h ]h"]h$]h&]hhuh1hhj~Qhhh*Documentation/filesystems/ext4/journal.rsthKubeh}(h]multiple-mount-protectionah ]h"]multiple mount protectionah$]h&]uh1hhhhhhjuQhKubh)}(hhh](h)}(hJournal (jbd2)h]hJournal (jbd2)}(hj.VhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj+Vhhhj"VhKubh)}(hX'Introduced in ext3, the ext4 filesystem employs a journal to protect the filesystem against metadata inconsistencies in the case of a system crash. Up to 10,240,000 file system blocks (see man mke2fs(8) for more details on journal size limits) can be reserved inside the filesystem as a place to land “important” data writes on-disk as quickly as possible. Once the important data transaction is fully written to the disk and flushed from the disk write cache, a record of the data being committed is also written to the journal. At some later point in time, the journal code writes the transactions to their final locations on disk (this could involve a lot of seeking or a lot of small read-write-erases) before erasing the commit record. Should the system crash during the second slow write, the journal can be replayed all the way to the latest commit record, guaranteeing the atomicity of whatever gets written through the journal to the disk. The effect of this is to guarantee that the filesystem does not become stuck midway through a metadata update.h]hX'Introduced in ext3, the ext4 filesystem employs a journal to protect the filesystem against metadata inconsistencies in the case of a system crash. Up to 10,240,000 file system blocks (see man mke2fs(8) for more details on journal size limits) can be reserved inside the filesystem as a place to land “important” data writes on-disk as quickly as possible. Once the important data transaction is fully written to the disk and flushed from the disk write cache, a record of the data being committed is also written to the journal. At some later point in time, the journal code writes the transactions to their final locations on disk (this could involve a lot of seeking or a lot of small read-write-erases) before erasing the commit record. Should the system crash during the second slow write, the journal can be replayed all the way to the latest commit record, guaranteeing the atomicity of whatever gets written through the journal to the disk. The effect of this is to guarantee that the filesystem does not become stuck midway through a metadata update.}(hjWubah}(h]h ]h"]h$]h&]uh1jhj;Wubj)}(hhh]h)}(h[descriptor_block (data_blocks or revocation_block) [more data or revocations] commmit_blockh]h[descriptor_block (data_blocks or revocation_block) [more data or revocations] commmit_block}(hjXWhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKBhjUWubah}(h]h ]h"]h$]h&]uh1jhj;Wubj)}(hhh]h)}(h[more transactions...]h]h[more transactions...]}(hjoWhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKDhjlWubah}(h]h ]h"]h$]h&]uh1jhj;Wubeh}(h]h ]h"]h$]h&]uh1j{hj8Wubah}(h]h ]h"]h$]h&]uh1jvhjWubj)}(hhh]j|)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]uh1jhjWubj)}(hhh]h)}(hOne transactionh]hOne transaction}(hjWhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKFhjWubah}(h]h ]h"]h$]h&]uh1jhjWubj)}(hhh]h}(h]h ]h"]h$]h&]uh1jhjWubeh}(h]h ]h"]h$]h&]uh1j{hjWubah}(h]h ]h"]h$]h&]uh1jhjWubeh}(h]h ]h"]h$]h&]colsKuh1jJhjWubah}(h]h ]j,ah"]h$]h&]uh1jEhjVhhhNhNubh)}(hXNotice that a transaction begins with either a descriptor and some data, or a block revocation list. A finished transaction always ends with a commit. If there is no commit record (or the checksums don't match), the transaction will be discarded during replay.h]hXNotice that a transaction begins with either a descriptor and some data, or a block revocation list. A finished transaction always ends with a commit. If there is no commit record (or the checksums don’t match), the transaction will be discarded during replay.}(hjWhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKIhjVhhubeh}(h]layoutah ]h"]layoutah$]h&]uh1hhj+Vhhhj"VhK9ubh)}(hhh](h)}(hExternal Journalh]hExternal Journal}(hjWhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjWhhhj"VhKOubh)}(hXOptionally, an ext4 filesystem can be created with an external journal device (as opposed to an internal journal, which uses a reserved inode). In this case, on the filesystem device, ``s_journal_inum`` should be zero and ``s_journal_uuid`` should be set. On the journal device there will be an ext4 super block in the usual place, with a matching UUID. The journal superblock will be in the next full block after the superblock.h](hOptionally, an ext4 filesystem can be created with an external journal device (as opposed to an internal journal, which uses a reserved inode). In this case, on the filesystem device, }(hjWhhhNhNubj,)}(h``s_journal_inum``h]hs_journal_inum}(hjXhhhNhNubah}(h]h ]h"]h$]h&]uh1j+hjWubh should be zero and }(hjWhhhNhNubj,)}(h``s_journal_uuid``h]hs_journal_uuid}(hjXhhhNhNubah}(h]h ]h"]h$]h&]uh1j+hjWubh should be set. On the journal device there will be an ext4 super block in the usual place, with a matching UUID. The journal superblock will be in the next full block after the superblock.}(hjWhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhj"VhKQhjWhhubjF)}(hhh]jK)}(hhh](jP)}(hhh]h}(h]h ]h"]h$]h&]jZK uh1jOhj3XubjP)}(hhh]h}(h]h ]h"]h$]h&]jZK uh1jOhj3XubjP)}(hhh]h}(h]h ]h"]h$]h&]jZK uh1jOhj3XubjP)}(hhh]h}(h]h ]h"]h$]h&]jZK uh1jOhj3XubjP)}(hhh]h}(h]h ]h"]h$]h&]jZK uh1jOhj3Xubjw)}(hhh]j|)}(hhh](j)}(hhh]h)}(h1024 bytes of paddingh]h1024 bytes of padding}(hjlXhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhK]hjiXubah}(h]h ]h"]h$]h&]uh1jhjfXubj)}(hhh]h)}(hext4 Superblockh]hext4 Superblock}(hjXhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhK^hjXubah}(h]h ]h"]h$]h&]uh1jhjfXubj)}(hhh]h)}(hJournal Superblockh]hJournal Superblock}(hjXhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhK_hjXubah}(h]h ]h"]h$]h&]uh1jhjfXubj)}(hhh]h)}(h[descriptor_block (data_blocks or revocation_block) [more data or revocations] commmit_blockh]h[descriptor_block (data_blocks or revocation_block) [more data or revocations] commmit_block}(hjXhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhK`hjXubah}(h]h ]h"]h$]h&]uh1jhjfXubj)}(hhh]h)}(h[more transactions...]h]h[more transactions...]}(hjXhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKbhjXubah}(h]h ]h"]h$]h&]uh1jhjfXubeh}(h]h ]h"]h$]h&]uh1j{hjcXubah}(h]h ]h"]h$]h&]uh1jvhj3Xubj)}(hhh]j|)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]uh1jhjXubj)}(hhh]h}(h]h ]h"]h$]h&]uh1jhjXubj)}(hhh]h}(h]h ]h"]h$]h&]uh1jhjXubj)}(hhh]h)}(hOne transactionh]hOne transaction}(hj YhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKfhj Yubah}(h]h ]h"]h$]h&]uh1jhjXubj)}(hhh]h}(h]h ]h"]h$]h&]uh1jhjXubeh}(h]h ]h"]h$]h&]uh1j{hjXubah}(h]h ]h"]h$]h&]uh1jhj3Xubeh}(h]h ]h"]h$]h&]colsKuh1jJhj0Xubah}(h]h ]j,ah"]h$]h&]uh1jEhjWhhhNhNubeh}(h]external-journalah ]h"]external journalah$]h&]uh1hhj+Vhhhj"VhKOubh)}(hhh](h)}(h Block Headerh]h Block Header}(hjMYhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjJYhhhj"VhKjubh)}(h[Every block in the journal starts with a common 12-byte header ``struct journal_header_s``:h](h?Every block in the journal starts with a common 12-byte header }(hj[YhhhNhNubj,)}(h``struct journal_header_s``h]hstruct journal_header_s}(hjcYhhhNhNubah}(h]h ]h"]h$]h&]uh1j+hj[Yubh:}(hj[YhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhj"VhKlhjJYhhubjF)}(hhh]jK)}(hhh](jP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhj~YubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhj~YubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhj~YubjP)}(hhh]h}(h]h ]h"]h$]h&]jZK(uh1jOhj~Yubjw)}(hhh]j|)}(hhh](j)}(hhh]h)}(hOffseth]hOffset}(hjYhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKshjYubah}(h]h ]h"]h$]h&]uh1jhjYubj)}(hhh]h)}(hTypeh]hType}(hjYhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKthjYubah}(h]h ]h"]h$]h&]uh1jhjYubj)}(hhh]h)}(hNameh]hName}(hjYhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKuhjYubah}(h]h ]h"]h$]h&]uh1jhjYubj)}(hhh]h)}(h Descriptionh]h Description}(hjYhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKvhjYubah}(h]h ]h"]h$]h&]uh1jhjYubeh}(h]h ]h"]h$]h&]uh1j{hjYubah}(h]h ]h"]h$]h&]uh1jvhj~Yubj)}(hhh](j|)}(hhh](j)}(hhh]h)}(h0x0h]h0x0}(hjZhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKwhjZubah}(h]h ]h"]h$]h&]uh1jhjZubj)}(hhh]h)}(h__be32h]h__be32}(hj3ZhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKxhj0Zubah}(h]h ]h"]h$]h&]uh1jhjZubj)}(hhh]h)}(hh_magich]hh_magic}(hjJZhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKyhjGZubah}(h]h ]h"]h$]h&]uh1jhjZubj)}(hhh]h)}(hjbd2 magic number, 0xC03B3998.h]hjbd2 magic number, 0xC03B3998.}(hjaZhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKzhj^Zubah}(h]h ]h"]h$]h&]uh1jhjZubeh}(h]h ]h"]h$]h&]uh1j{hjZubj|)}(hhh](j)}(hhh]h)}(h0x4h]h0x4}(hjZhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhK{hj~Zubah}(h]h ]h"]h$]h&]uh1jhj{Zubj)}(hhh]h)}(h__be32h]h__be32}(hjZhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhK|hjZubah}(h]h ]h"]h$]h&]uh1jhj{Zubj)}(hhh]h)}(h h_blocktypeh]h h_blocktype}(hjZhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhK}hjZubah}(h]h ]h"]h$]h&]uh1jhj{Zubj)}(hhh]h)}(hMDescription of what this block contains. See the jbd2_blocktype_ table below.h](h1Description of what this block contains. See the }(hjZhhhNhNubj)}(hjbd2_blocktype_h]hjbd2_blocktype}(hjZhhhNhNubah}(h]h ]h"]h$]h&]namejbd2_blocktypejjbd2-blocktypeuh1jhjZjKubh table below.}(hjZhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhj"VhK~hjZubah}(h]h ]h"]h$]h&]uh1jhj{Zubeh}(h]h ]h"]h$]h&]uh1j{hjZubj|)}(hhh](j)}(hhh]h)}(h0x8h]h0x8}(hjZhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjZubah}(h]h ]h"]h$]h&]uh1jhjZubj)}(hhh]h)}(h__be32h]h__be32}(hj[hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj[ubah}(h]h ]h"]h$]h&]uh1jhjZubj)}(hhh]h)}(h h_sequenceh]h h_sequence}(hj)[hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj&[ubah}(h]h ]h"]h$]h&]uh1jhjZubj)}(hhh]h)}(h-The transaction ID that goes with this block.h]h-The transaction ID that goes with this block.}(hj@[hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj=[ubah}(h]h ]h"]h$]h&]uh1jhjZubeh}(h]h ]h"]h$]h&]uh1j{hjZubeh}(h]h ]h"]h$]h&]uh1jhj~Yubeh}(h]h ]h"]h$]h&]colsKuh1jJhj{Yubah}(h]h ]j,ah"]h$]h&]uh1jEhjJYhhhNhNubj-)}(h.. _jbd2_blocktype:h]h}(h]h ]h"]h$]h&]jjZuh1j-hMhjJYhhhj"Vj-Kubh)}(h)The journal block type can be any one of:h]h)The journal block type can be any one of:}(hjw[hhhNhNubah}(h]jZah ]h"]jbd2_blocktypeah$]h&]uh1hhj"VhKhjJYhhj-}j[jm[sj -}jZjm[sj-KubjF)}(hhh]jK)}(hhh](jP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhj[ubjP)}(hhh]h}(h]h ]h"]h$]h&]jZK@uh1jOhj[ubjw)}(hhh]j|)}(hhh](j)}(hhh]h)}(hValueh]hValue}(hj[hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj[ubah}(h]h ]h"]h$]h&]uh1jhj[ubj)}(hhh]h)}(h Descriptionh]h Description}(hj[hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj[ubah}(h]h ]h"]h$]h&]uh1jhj[ubeh}(h]h ]h"]h$]h&]uh1j{hj[ubah}(h]h ]h"]h$]h&]uh1jvhj[ubj)}(hhh](j|)}(hhh](j)}(hhh]h)}(hj.h]h1}(hj[hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj[ubah}(h]h ]h"]h$]h&]uh1jhj[ubj)}(hhh]h)}(hsDescriptor. This block precedes a series of data blocks that were written through the journal during a transaction.h]hsDescriptor. This block precedes a series of data blocks that were written through the journal during a transaction.}(hj[hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj[ubah}(h]h ]h"]h$]h&]uh1jhj[ubeh}(h]h ]h"]h$]h&]uh1j{hj[ubj|)}(hhh](j)}(hhh]h)}(hj.h]h2}(hj\hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj\ubah}(h]h ]h"]h$]h&]uh1jhj\ubj)}(hhh]h)}(hJBlock commit record. This block signifies the completion of a transaction.h]hJBlock commit record. This block signifies the completion of a transaction.}(hj5\hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj2\ubah}(h]h ]h"]h$]h&]uh1jhj\ubeh}(h]h ]h"]h$]h&]uh1j{hj[ubj|)}(hhh](j)}(hhh]h)}(hj!/h]h3}(hjU\hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjR\ubah}(h]h ]h"]h$]h&]uh1jhjO\ubj)}(hhh]h)}(hJournal superblock, v1.h]hJournal superblock, v1.}(hjk\hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjh\ubah}(h]h ]h"]h$]h&]uh1jhjO\ubeh}(h]h ]h"]h$]h&]uh1j{hj[ubj|)}(hhh](j)}(hhh]h)}(hj0h]h4}(hj\hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj\ubah}(h]h ]h"]h$]h&]uh1jhj\ubj)}(hhh]h)}(hJournal superblock, v2.h]hJournal superblock, v2.}(hj\hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj\ubah}(h]h ]h"]h$]h&]uh1jhj\ubeh}(h]h ]h"]h$]h&]uh1j{hj[ubj|)}(hhh](j)}(hhh]h)}(h5h]h5}(hj\hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj\ubah}(h]h ]h"]h$]h&]uh1jhj\ubj)}(hhh]h)}(hBlock revocation records. This speeds up recovery by enabling the journal to skip writing blocks that were subsequently rewritten.h]hBlock revocation records. This speeds up recovery by enabling the journal to skip writing blocks that were subsequently rewritten.}(hj\hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj\ubah}(h]h ]h"]h$]h&]uh1jhj\ubeh}(h]h ]h"]h$]h&]uh1j{hj[ubeh}(h]h ]h"]h$]h&]uh1jhj[ubeh}(h]h ]h"]h$]h&]colsKuh1jJhj[ubah}(h]h ]j,ah"]h$]h&]uh1jEhjJYhhhNhNubeh}(h] block-headerah ]h"] block headerah$]h&]uh1hhj+Vhhhj"VhKjubh)}(hhh](h)}(h Super Blockh]h Super Block}(hj]hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj ]hhhj"VhKubh)}(hThe super block for the journal is much simpler as compared to ext4's. The key data kept within are size of the journal, and where to find the start of the log of transactions.h]hThe super block for the journal is much simpler as compared to ext4’s. The key data kept within are size of the journal, and where to find the start of the log of transactions.}(hj]hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj ]hhubh)}(h`The journal superblock is recorded as ``struct journal_superblock_s``, which is 1024 bytes long:h](h&The journal superblock is recorded as }(hj,]hhhNhNubj,)}(h``struct journal_superblock_s``h]hstruct journal_superblock_s}(hj4]hhhNhNubah}(h]h ]h"]h$]h&]uh1j+hj,]ubh, which is 1024 bytes long:}(hj,]hhhNhNubeh}(h]h ]h"]h$]h&]uh1hhj"VhKhj ]hhubjF)}(hhh]jK)}(hhh](jP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhjO]ubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhjO]ubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhjO]ubjP)}(hhh]h}(h]h ]h"]h$]h&]jZK(uh1jOhjO]ubjw)}(hhh]j|)}(hhh](j)}(hhh]h)}(hOffseth]hOffset}(hj]hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj|]ubah}(h]h ]h"]h$]h&]uh1jhjy]ubj)}(hhh]h)}(hTypeh]hType}(hj]hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj]ubah}(h]h ]h"]h$]h&]uh1jhjy]ubj)}(hhh]h)}(hNameh]hName}(hj]hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj]ubah}(h]h ]h"]h$]h&]uh1jhjy]ubj)}(hhh]h)}(h Descriptionh]h Description}(hj]hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj]ubah}(h]h ]h"]h$]h&]uh1jhjy]ubeh}(h]h ]h"]h$]h&]uh1j{hjv]ubah}(h]h ]h"]h$]h&]uh1jvhjO]ubj)}(hhh](j|)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]uh1jhj]ubj)}(hhh]h}(h]h ]h"]h$]h&]uh1jhj]ubj)}(hhh]h}(h]h ]h"]h$]h&]uh1jhj]ubj)}(hhh]h)}(h*Static information describing the journal.h]h*Static information describing the journal.}(hj^hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj^ubah}(h]h ]h"]h$]h&]uh1jhj]ubeh}(h]h ]h"]h$]h&]uh1j{hj]ubj|)}(hhh](j)}(hhh]h)}(h0x0h]h0x0}(hj(^hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj%^ubah}(h]h ]h"]h$]h&]uh1jhj"^ubj)}(hhh]h)}(hjournal_header_t (12 bytes)h]hjournal_header_t (12 bytes)}(hj?^hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj<^ubah}(h]h ]h"]h$]h&]uh1jhj"^ubj)}(hhh]h)}(hs_headerh]hs_header}(hjV^hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjS^ubah}(h]h ]h"]h$]h&]uh1jhj"^ubj)}(hhh]h)}(h/Common header identifying this as a superblock.h]h/Common header identifying this as a superblock.}(hjm^hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjj^ubah}(h]h ]h"]h$]h&]uh1jhj"^ubeh}(h]h ]h"]h$]h&]uh1j{hj]ubj|)}(hhh](j)}(hhh]h)}(h0xCh]h0xC}(hj^hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj^ubah}(h]h ]h"]h$]h&]uh1jhj^ubj)}(hhh]h)}(h__be32h]h__be32}(hj^hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj^ubah}(h]h ]h"]h$]h&]uh1jhj^ubj)}(hhh]h)}(h s_blocksizeh]h s_blocksize}(hj^hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj^ubah}(h]h ]h"]h$]h&]uh1jhj^ubj)}(hhh]h)}(hJournal device block size.h]hJournal device block size.}(hj^hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj^ubah}(h]h ]h"]h$]h&]uh1jhj^ubeh}(h]h ]h"]h$]h&]uh1j{hj]ubj|)}(hhh](j)}(hhh]h)}(h0x10h]h0x10}(hj^hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj^ubah}(h]h ]h"]h$]h&]uh1jhj^ubj)}(hhh]h)}(h__be32h]h__be32}(hj _hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj_ubah}(h]h ]h"]h$]h&]uh1jhj^ubj)}(hhh]h)}(hs_maxlenh]hs_maxlen}(hj _hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj_ubah}(h]h ]h"]h$]h&]uh1jhj^ubj)}(hhh]h)}(h'Total number of blocks in this journal.h]h'Total number of blocks in this journal.}(hj7_hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj4_ubah}(h]h ]h"]h$]h&]uh1jhj^ubeh}(h]h ]h"]h$]h&]uh1j{hj]ubj|)}(hhh](j)}(hhh]h)}(h0x14h]h0x14}(hjW_hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjT_ubah}(h]h ]h"]h$]h&]uh1jhjQ_ubj)}(hhh]h)}(h__be32h]h__be32}(hjn_hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjk_ubah}(h]h ]h"]h$]h&]uh1jhjQ_ubj)}(hhh]h)}(hs_firsth]hs_first}(hj_hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj_ubah}(h]h ]h"]h$]h&]uh1jhjQ_ubj)}(hhh]h)}(hFirst block of log information.h]hFirst block of log information.}(hj_hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj_ubah}(h]h ]h"]h$]h&]uh1jhjQ_ubeh}(h]h ]h"]h$]h&]uh1j{hj]ubj|)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]uh1jhj_ubj)}(hhh]h}(h]h ]h"]h$]h&]uh1jhj_ubj)}(hhh]h}(h]h ]h"]h$]h&]uh1jhj_ubj)}(hhh]h)}(haubah}(h]h ]h"]h$]h&]uh1jhj aubeh}(h]h ]h"]h$]h&]uh1j{hj]ubj|)}(hhh](j)}(hhh]h)}(h0x24h]h0x24}(hjaahhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj^aubah}(h]h ]h"]h$]h&]uh1jhj[aubj)}(hhh]h)}(h__be32h]h__be32}(hjxahhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjuaubah}(h]h ]h"]h$]h&]uh1jhj[aubj)}(hhh]h)}(hs_feature_compat;h]hs_feature_compat;}(hjahhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjaubah}(h]h ]h"]h$]h&]uh1jhj[aubj)}(hhh]h)}(h9Compatible feature set. See the table jbd2_compat_ below.h](h&Compatible feature set. See the table }(hjahhhNhNubj)}(h jbd2_compat_h]h jbd2_compat}(hjahhhNhNubah}(h]h ]h"]h$]h&]name jbd2_compatj jbd2-compatuh1jhjajKubh below.}(hjahhhNhNubeh}(h]h ]h"]h$]h&]uh1hhj"VhKhjaubah}(h]h ]h"]h$]h&]uh1jhj[aubeh}(h]h ]h"]h$]h&]uh1j{hj]ubj|)}(hhh](j)}(hhh]h)}(h0x28h]h0x28}(hjahhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjaubah}(h]h ]h"]h$]h&]uh1jhjaubj)}(hhh]h)}(h__be32h]h__be32}(hjahhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjaubah}(h]h ]h"]h$]h&]uh1jhjaubj)}(hhh]h)}(hs_feature_incompath]hs_feature_incompat}(hj bhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjbubah}(h]h ]h"]h$]h&]uh1jhjaubj)}(hhh]h)}(h=Incompatible feature set. See the table jbd2_incompat_ below.h](h(Incompatible feature set. See the table }(hj bhhhNhNubj)}(hjbd2_incompat_h]h jbd2_incompat}(hj(bhhhNhNubah}(h]h ]h"]h$]h&]name jbd2_incompatj jbd2-incompatuh1jhj bjKubh below.}(hj bhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhj"VhKhjbubah}(h]h ]h"]h$]h&]uh1jhjaubeh}(h]h ]h"]h$]h&]uh1j{hj]ubj|)}(hhh](j)}(hhh]h)}(h0x2Ch]h0x2C}(hjUbhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjRbubah}(h]h ]h"]h$]h&]uh1jhjObubj)}(hhh]h)}(h__be32h]h__be32}(hjlbhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjibubah}(h]h ]h"]h$]h&]uh1jhjObubj)}(hhh]h)}(hs_feature_ro_compath]hs_feature_ro_compat}(hjbhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjbubah}(h]h ]h"]h$]h&]uh1jhjObubj)}(hhh]h)}(hFRead-only compatible feature set. There aren't any of these currently.h]hHRead-only compatible feature set. There aren’t any of these currently.}(hjbhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjbubah}(h]h ]h"]h$]h&]uh1jhjObubeh}(h]h ]h"]h$]h&]uh1j{hj]ubj|)}(hhh](j)}(hhh]h)}(h0x30h]h0x30}(hjbhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjbubah}(h]h ]h"]h$]h&]uh1jhjbubj)}(hhh]h)}(h__u8h]h__u8}(hjbhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjbubah}(h]h ]h"]h$]h&]uh1jhjbubj)}(hhh]h)}(h s_uuid[16]h]h s_uuid[16]}(hjbhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjbubah}(h]h ]h"]h$]h&]uh1jhjbubj)}(hhh]h)}(hb128-bit uuid for journal. This is compared against the copy in the ext4 super block at mount time.h]hb128-bit uuid for journal. This is compared against the copy in the ext4 super block at mount time.}(hjbhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjbubah}(h]h ]h"]h$]h&]uh1jhjbubeh}(h]h ]h"]h$]h&]uh1j{hj]ubj|)}(hhh](j)}(hhh]h)}(h0x40h]h0x40}(hjchhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjcubah}(h]h ]h"]h$]h&]uh1jhjcubj)}(hhh]h)}(h__be32h]h__be32}(hj6chhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj3cubah}(h]h ]h"]h$]h&]uh1jhjcubj)}(hhh]h)}(h s_nr_usersh]h s_nr_users}(hjMchhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjJcubah}(h]h ]h"]h$]h&]uh1jhjcubj)}(hhh]h)}(h,Number of file systems sharing this journal.h]h,Number of file systems sharing this journal.}(hjdchhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjacubah}(h]h ]h"]h$]h&]uh1jhjcubeh}(h]h ]h"]h$]h&]uh1j{hj]ubj|)}(hhh](j)}(hhh]h)}(h0x44h]h0x44}(hjchhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjcubah}(h]h ]h"]h$]h&]uh1jhj~cubj)}(hhh]h)}(h__be32h]h__be32}(hjchhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjcubah}(h]h ]h"]h$]h&]uh1jhj~cubj)}(hhh]h)}(h s_dynsuperh]h s_dynsuper}(hjchhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjcubah}(h]h ]h"]h$]h&]uh1jhj~cubj)}(hhh]h)}(h1Location of dynamic super block copy. (Not used?)h]h1Location of dynamic super block copy. (Not used?)}(hjchhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjcubah}(h]h ]h"]h$]h&]uh1jhj~cubeh}(h]h ]h"]h$]h&]uh1j{hj]ubj|)}(hhh](j)}(hhh]h)}(h0x48h]h0x48}(hjchhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjcubah}(h]h ]h"]h$]h&]uh1jhjcubj)}(hhh]h)}(h__be32h]h__be32}(hjdhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjcubah}(h]h ]h"]h$]h&]uh1jhjcubj)}(hhh]h)}(hs_max_transactionh]hs_max_transaction}(hjdhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjdubah}(h]h ]h"]h$]h&]uh1jhjcubj)}(hhh]h)}(h4Limit of journal blocks per transaction. (Not used?)h]h4Limit of journal blocks per transaction. (Not used?)}(hj.dhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj+dubah}(h]h ]h"]h$]h&]uh1jhjcubeh}(h]h ]h"]h$]h&]uh1j{hj]ubj|)}(hhh](j)}(hhh]h)}(h0x4Ch]h0x4C}(hjNdhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjKdubah}(h]h ]h"]h$]h&]uh1jhjHdubj)}(hhh]h)}(h__be32h]h__be32}(hjedhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjbdubah}(h]h ]h"]h$]h&]uh1jhjHdubj)}(hhh]h)}(hs_max_trans_datah]hs_max_trans_data}(hj|dhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjydubah}(h]h ]h"]h$]h&]uh1jhjHdubj)}(hhh]h)}(h1Limit of data blocks per transaction. (Not used?)h]h1Limit of data blocks per transaction. (Not used?)}(hjdhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjdubah}(h]h ]h"]h$]h&]uh1jhjHdubeh}(h]h ]h"]h$]h&]uh1j{hj]ubj|)}(hhh](j)}(hhh]h)}(h0x50h]h0x50}(hjdhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjdubah}(h]h ]h"]h$]h&]uh1jhjdubj)}(hhh]h)}(h__u8h]h__u8}(hjdhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjdubah}(h]h ]h"]h$]h&]uh1jhjdubj)}(hhh]h)}(hs_checksum_typeh]hs_checksum_type}(hjdhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjdubah}(h]h ]h"]h$]h&]uh1jhjdubj)}(hhh]h)}(hPChecksum algorithm used for the journal. See jbd2_checksum_type_ for more info.h](h.Checksum algorithm used for the journal. See }(hjdhhhNhNubj)}(hjbd2_checksum_type_h]hjbd2_checksum_type}(hjehhhNhNubah}(h]h ]h"]h$]h&]namejbd2_checksum_typejjbd2-checksum-typeuh1jhjdjKubh for more info.}(hjdhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhj"VhKhjdubah}(h]h ]h"]h$]h&]uh1jhjdubeh}(h]h ]h"]h$]h&]uh1j{hj]ubj|)}(hhh](j)}(hhh]h)}(h0x51h]h0x51}(hj-ehhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhj*eubah}(h]h ]h"]h$]h&]uh1jhj'eubj)}(hhh]h)}(h__u8[3]h]h__u8[3]}(hjDehhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhKhjAeubah}(h]h ]h"]h$]h&]uh1jhj'eubj)}(hhh]h)}(h s_padding2h]h s_padding2}(hj[ehhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjXeubah}(h]h ]h"]h$]h&]uh1jhj'eubj)}(hhh]h}(h]h ]h"]h$]h&]uh1jhj'eubeh}(h]h ]h"]h$]h&]uh1j{hj]ubj|)}(hhh](j)}(hhh]h)}(h0x54h]h0x54}(hjehhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjeubah}(h]h ]h"]h$]h&]uh1jhj~eubj)}(hhh]h)}(h__be32h]h__be32}(hjehhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjeubah}(h]h ]h"]h$]h&]uh1jhj~eubj)}(hhh]h)}(hs_num_fc_blocksh]hs_num_fc_blocks}(hjehhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjeubah}(h]h ]h"]h$]h&]uh1jhj~eubj)}(hhh]h)}(h,Number of fast commit blocks in the journal.h]h,Number of fast commit blocks in the journal.}(hjehhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjeubah}(h]h ]h"]h$]h&]uh1jhj~eubeh}(h]h ]h"]h$]h&]uh1j{hj]ubj|)}(hhh](j)}(hhh]h)}(h0x58h]h0x58}(hjehhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjeubah}(h]h ]h"]h$]h&]uh1jhjeubj)}(hhh]h)}(h__be32h]h__be32}(hjfhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjeubah}(h]h ]h"]h$]h&]uh1jhjeubj)}(hhh]h)}(hs_headh]hs_head}(hjfhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjfubah}(h]h ]h"]h$]h&]uh1jhjeubj)}(hhh]h)}(hhBlock number of the head (first unused block) of the journal, only up-to-date when the journal is empty.h]hhBlock number of the head (first unused block) of the journal, only up-to-date when the journal is empty.}(hj.fhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM hj+fubah}(h]h ]h"]h$]h&]uh1jhjeubeh}(h]h ]h"]h$]h&]uh1j{hj]ubj|)}(hhh](j)}(hhh]h)}(h0x5Ch]h0x5C}(hjNfhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM hjKfubah}(h]h ]h"]h$]h&]uh1jhjHfubj)}(hhh]h)}(h__u32h]h__u32}(hjefhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM hjbfubah}(h]h ]h"]h$]h&]uh1jhjHfubj)}(hhh]h)}(h s_padding[40]h]h s_padding[40]}(hj|fhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM hjyfubah}(h]h ]h"]h$]h&]uh1jhjHfubj)}(hhh]h}(h]h ]h"]h$]h&]uh1jhjHfubeh}(h]h ]h"]h$]h&]uh1j{hj]ubj|)}(hhh](j)}(hhh]h)}(h0xFCh]h0xFC}(hjfhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjfubah}(h]h ]h"]h$]h&]uh1jhjfubj)}(hhh]h)}(h__be32h]h__be32}(hjfhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjfubah}(h]h ]h"]h$]h&]uh1jhjfubj)}(hhh]h)}(h s_checksumh]h s_checksum}(hjfhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjfubah}(h]h ]h"]h$]h&]uh1jhjfubj)}(hhh]h)}(h?Checksum of the entire superblock, with this field set to zero.h]h?Checksum of the entire superblock, with this field set to zero.}(hjfhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjfubah}(h]h ]h"]h$]h&]uh1jhjfubeh}(h]h ]h"]h$]h&]uh1j{hj]ubj|)}(hhh](j)}(hhh]h)}(h0x100h]h0x100}(hj ghhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjgubah}(h]h ]h"]h$]h&]uh1jhjgubj)}(hhh]h)}(h__u8h]h__u8}(hj!ghhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjgubah}(h]h ]h"]h$]h&]uh1jhjgubj)}(hhh]h)}(hs_users[16*48]h]hs_users[16*48]}(hj8ghhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhj5gubah}(h]h ]h"]h$]h&]uh1jhjgubj)}(hhh]h)}(hids of all file systems sharing the log. e2fsprogs/Linux don't allow shared external journals, but I imagine Lustre (or ocfs2?), which use the jbd2 code, might.h]hids of all file systems sharing the log. e2fsprogs/Linux don’t allow shared external journals, but I imagine Lustre (or ocfs2?), which use the jbd2 code, might.}(hjOghhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjLgubah}(h]h ]h"]h$]h&]uh1jhjgubeh}(h]h ]h"]h$]h&]uh1j{hj]ubeh}(h]h ]h"]h$]h&]uh1jhjO]ubeh}(h]h ]h"]h$]h&]colsKuh1jJhjL]ubah}(h]h ]j,ah"]h$]h&]uh1jEhj ]hhhNhNubj-)}(h.. _jbd2_compat:h]h}(h]h ]h"]h$]h&]jjauh1j-hMhj ]hhhj"Vj-Kubh)}(hAThe journal compat features are any combination of the following:h]hAThe journal compat features are any combination of the following:}(hjghhhNhNubah}(h]jaah ]h"] jbd2_compatah$]h&]uh1hhj"VhMhj ]hhj-}jgj|gsj -}jaj|gsj-KubjF)}(hhh]jK)}(hhh](jP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhjgubjP)}(hhh]h}(h]h ]h"]h$]h&]jZK@uh1jOhjgubjw)}(hhh]j|)}(hhh](j)}(hhh]h)}(hValueh]hValue}(hjghhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM"hjgubah}(h]h ]h"]h$]h&]uh1jhjgubj)}(hhh]h)}(h Descriptionh]h Description}(hjghhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM#hjgubah}(h]h ]h"]h$]h&]uh1jhjgubeh}(h]h ]h"]h$]h&]uh1j{hjgubah}(h]h ]h"]h$]h&]uh1jvhjgubj)}(hhh]j|)}(hhh](j)}(hhh]h)}(h0x1h]h0x1}(hjghhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM$hjgubah}(h]h ]h"]h$]h&]uh1jhjgubj)}(hhh]h)}(hNJournal maintains checksums on the data blocks. (JBD2_FEATURE_COMPAT_CHECKSUM)h]hNJournal maintains checksums on the data blocks. (JBD2_FEATURE_COMPAT_CHECKSUM)}(hjhhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM%hj hubah}(h]h ]h"]h$]h&]uh1jhjgubeh}(h]h ]h"]h$]h&]uh1j{hjgubah}(h]h ]h"]h$]h&]uh1jhjgubeh}(h]h ]h"]h$]h&]colsKuh1jJhjgubah}(h]h ]j,ah"]h$]h&]uh1jEhj ]hhhNhNubj-)}(h.. _jbd2_incompat:h]h}(h]h ]h"]h$]h&]jj8buh1j-hMhj ]hhhj"Vj-Kubh)}(hCThe journal incompat features are any combination of the following:h]hCThe journal incompat features are any combination of the following:}(hjFhhhhNhNubah}(h]j8bah ]h"] jbd2_incompatah$]h&]uh1hhj"VhM*hj ]hhj-}jRhjhjiubah}(h]h ]h"]h$]h&]uh1jhjiubj)}(hhh]h)}(hThis journal uses v3 of the checksum on-disk format. This is the same as v2, but the journal block tag size is fixed regardless of the size of block numbers. (JBD2_FEATURE_INCOMPAT_CSUM_V3)h]hThis journal uses v3 of the checksum on-disk format. This is the same as v2, but the journal block tag size is fixed regardless of the size of block numbers. (JBD2_FEATURE_INCOMPAT_CSUM_V3)}(hjihhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM?hjiubah}(h]h ]h"]h$]h&]uh1jhjiubeh}(h]h ]h"]h$]h&]uh1j{hjhubj|)}(hhh](j)}(hhh]h)}(h0x20h]h0x20}(hjihhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMBhjiubah}(h]h ]h"]h$]h&]uh1jhjiubj)}(hhh]h)}(hCJournal has fast commit blocks. (JBD2_FEATURE_INCOMPAT_FAST_COMMIT)h]hCJournal has fast commit blocks. (JBD2_FEATURE_INCOMPAT_FAST_COMMIT)}(hjihhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMChjiubah}(h]h ]h"]h$]h&]uh1jhjiubeh}(h]h ]h"]h$]h&]uh1j{hjhubeh}(h]h ]h"]h$]h&]uh1jhjZhubeh}(h]h ]h"]h$]h&]colsKuh1jJhjWhubah}(h]h ]j,ah"]h$]h&]uh1jEhj ]hhhNhNubj-)}(h.. _jbd2_checksum_type:h]h}(h]h ]h"]h$]h&]jjeuh1j-hMhj ]hhhj"Vj-Kubh)}(hcJournal checksum type codes are one of the following. crc32 or crc32c are the most likely choices.h]hcJournal checksum type codes are one of the following. crc32 or crc32c are the most likely choices.}(hjjhhhNhNubah}(h]jeah ]h"]jbd2_checksum_typeah$]h&]uh1hhj"VhMGhj ]hhj-}j%jjjsj -}jejjsj-KubjF)}(hhh]jK)}(hhh](jP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhj-jubjP)}(hhh]h}(h]h ]h"]h$]h&]jZK@uh1jOhj-jubjw)}(hhh]j|)}(hhh](j)}(hhh]h)}(hValueh]hValue}(hjKjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMNhjHjubah}(h]h ]h"]h$]h&]uh1jhjEjubj)}(hhh]h)}(h Descriptionh]h Description}(hjbjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMOhj_jubah}(h]h ]h"]h$]h&]uh1jhjEjubeh}(h]h ]h"]h$]h&]uh1j{hjBjubah}(h]h ]h"]h$]h&]uh1jvhj-jubj)}(hhh](j|)}(hhh](j)}(hhh]h)}(hj.h]h1}(hjjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMPhjjubah}(h]h ]h"]h$]h&]uh1jhjjubj)}(hhh]h)}(hCRC32h]hCRC32}(hjjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMQhjjubah}(h]h ]h"]h$]h&]uh1jhjjubeh}(h]h ]h"]h$]h&]uh1j{hjjubj|)}(hhh](j)}(hhh]h)}(hj.h]h2}(hjjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMRhjjubah}(h]h ]h"]h$]h&]uh1jhjjubj)}(hhh]h)}(hMD5h]hMD5}(hjjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMShjjubah}(h]h ]h"]h$]h&]uh1jhjjubeh}(h]h ]h"]h$]h&]uh1j{hjjubj|)}(hhh](j)}(hhh]h)}(hj!/h]h3}(hjjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMThjjubah}(h]h ]h"]h$]h&]uh1jhjjubj)}(hhh]h)}(hSHA1h]hSHA1}(hj khhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMUhj kubah}(h]h ]h"]h$]h&]uh1jhjjubeh}(h]h ]h"]h$]h&]uh1j{hjjubj|)}(hhh](j)}(hhh]h)}(hj0h]h4}(hj-khhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMVhj*kubah}(h]h ]h"]h$]h&]uh1jhj'kubj)}(hhh]h)}(hCRC32Ch]hCRC32C}(hjCkhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMWhj@kubah}(h]h ]h"]h$]h&]uh1jhj'kubeh}(h]h ]h"]h$]h&]uh1j{hjjubeh}(h]h ]h"]h$]h&]uh1jhj-jubeh}(h]h ]h"]h$]h&]colsKuh1jJhj*jubah}(h]h ]j,ah"]h$]h&]uh1jEhj ]hhhNhNubeh}(h]id1ah ]h"]h$]jDah&]uh1hhj+Vhhhj"VhKj-Kubh)}(hhh](h)}(hDescriptor Blockh]hDescriptor Block}(hjzkhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjwkhhhj"VhMZubh)}(hXTThe descriptor block contains an array of journal block tags that describe the final locations of the data blocks that follow in the journal. Descriptor blocks are open-coded instead of being completely described by a data structure, but here is the block structure anyway. Descriptor blocks consume at least 36 bytes, but use a full block:h]hXTThe descriptor block contains an array of journal block tags that describe the final locations of the data blocks that follow in the journal. Descriptor blocks are open-coded instead of being completely described by a data structure, but here is the block structure anyway. Descriptor blocks consume at least 36 bytes, but use a full block:}(hjkhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM\hjwkhhubjF)}(hhh]jK)}(hhh](jP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhjkubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhjkubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhjkubjP)}(hhh]h}(h]h ]h"]h$]h&]jZK(uh1jOhjkubjw)}(hhh]j|)}(hhh](j)}(hhh]h)}(hOffseth]hOffset}(hjkhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMfhjkubah}(h]h ]h"]h$]h&]uh1jhjkubj)}(hhh]h)}(hTypeh]hType}(hjkhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMghjkubah}(h]h ]h"]h$]h&]uh1jhjkubj)}(hhh]h)}(hNameh]hName}(hjkhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhhjkubah}(h]h ]h"]h$]h&]uh1jhjkubj)}(hhh]h)}(h Descriptorh]h Descriptor}(hjlhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMihj lubah}(h]h ]h"]h$]h&]uh1jhjkubeh}(h]h ]h"]h$]h&]uh1j{hjkubah}(h]h ]h"]h$]h&]uh1jvhjkubj)}(hhh](j|)}(hhh](j)}(hhh]h)}(h0x0h]h0x0}(hj7lhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMjhj4lubah}(h]h ]h"]h$]h&]uh1jhj1lubj)}(hhh]h)}(hjournal_header_th]hjournal_header_t}(hjNlhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMkhjKlubah}(h]h ]h"]h$]h&]uh1jhj1lubj)}(hhh]h)}(h (open coded)h]h (open coded)}(hjelhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMlhjblubah}(h]h ]h"]h$]h&]uh1jhj1lubj)}(hhh]h)}(hCommon block header.h]hCommon block header.}(hj|lhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMmhjylubah}(h]h ]h"]h$]h&]uh1jhj1lubeh}(h]h ]h"]h$]h&]uh1j{hj.lubj|)}(hhh](j)}(hhh]h)}(h0xCh]h0xC}(hjlhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMnhjlubah}(h]h ]h"]h$]h&]uh1jhjlubj)}(hhh]h)}(hstruct journal_block_tag_sh]hstruct journal_block_tag_s}(hjlhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMohjlubah}(h]h ]h"]h$]h&]uh1jhjlubj)}(hhh]h)}(hopen coded array[]h]hopen coded array[]}(hjlhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMphjlubah}(h]h ]h"]h$]h&]uh1jhjlubj)}(hhh]h)}(hmEnough tags either to fill up the block or to describe all the data blocks that follow this descriptor block.h]hmEnough tags either to fill up the block or to describe all the data blocks that follow this descriptor block.}(hjlhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMqhjlubah}(h]h ]h"]h$]h&]uh1jhjlubeh}(h]h ]h"]h$]h&]uh1j{hj.lubeh}(h]h ]h"]h$]h&]uh1jhjkubeh}(h]h ]h"]h$]h&]colsKuh1jJhjkubah}(h]h ]j,ah"]h$]h&]uh1jEhjwkhhhNhNubh)}(huJournal block tags have any of the following formats, depending on which journal feature and block tag flags are set.h]huJournal block tags have any of the following formats, depending on which journal feature and block tag flags are set.}(hjmhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMthjwkhhubh)}(hIf JBD2_FEATURE_INCOMPAT_CSUM_V3 is set, the journal block tag is defined as ``struct journal_block_tag3_s``, which looks like the following. The size is 16 or 32 bytes.h](hMIf JBD2_FEATURE_INCOMPAT_CSUM_V3 is set, the journal block tag is defined as }(hjmhhhNhNubj,)}(h``struct journal_block_tag3_s``h]hstruct journal_block_tag3_s}(hj$mhhhNhNubah}(h]h ]h"]h$]h&]uh1j+hjmubh=, which looks like the following. The size is 16 or 32 bytes.}(hjmhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhj"VhMwhjwkhhubjF)}(hhh]jK)}(hhh](jP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhj?mubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhj?mubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhj?mubjP)}(hhh]h}(h]h ]h"]h$]h&]jZK(uh1jOhj?mubjw)}(hhh]j|)}(hhh](j)}(hhh]h)}(hOffseth]hOffset}(hjomhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjlmubah}(h]h ]h"]h$]h&]uh1jhjimubj)}(hhh]h)}(hTypeh]hType}(hjmhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjmubah}(h]h ]h"]h$]h&]uh1jhjimubj)}(hhh]h)}(hNameh]hName}(hjmhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjmubah}(h]h ]h"]h$]h&]uh1jhjimubj)}(hhh]h)}(h Descriptorh]h Descriptor}(hjmhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjmubah}(h]h ]h"]h$]h&]uh1jhjimubeh}(h]h ]h"]h$]h&]uh1j{hjfmubah}(h]h ]h"]h$]h&]uh1jvhj?mubj)}(hhh](j|)}(hhh](j)}(hhh]h)}(h0x0h]h0x0}(hjmhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjmubah}(h]h ]h"]h$]h&]uh1jhjmubj)}(hhh]h)}(h__be32h]h__be32}(hjmhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjmubah}(h]h ]h"]h$]h&]uh1jhjmubj)}(hhh]h)}(h t_blocknrh]h t_blocknr}(hj nhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjnubah}(h]h ]h"]h$]h&]uh1jhjmubj)}(hhh]h)}(hZLower 32-bits of the location of where the corresponding data block should end up on disk.h]hZLower 32-bits of the location of where the corresponding data block should end up on disk.}(hj"nhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjnubah}(h]h ]h"]h$]h&]uh1jhjmubeh}(h]h ]h"]h$]h&]uh1j{hjmubj|)}(hhh](j)}(hhh]h)}(h0x4h]h0x4}(hjBnhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhj?nubah}(h]h ]h"]h$]h&]uh1jhjqubah}(h]h ]h"]h$]h&]uh1jhj;qubj)}(hhh]h)}(h:The data block was deleted by the transaction. (Not used?)h]h:The data block was deleted by the transaction. (Not used?)}(hjXqhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjUqubah}(h]h ]h"]h$]h&]uh1jhj;qubeh}(h]h ]h"]h$]h&]uh1j{hjpubj|)}(hhh](j)}(hhh]h)}(h0x8h]h0x8}(hjxqhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjuqubah}(h]h ]h"]h$]h&]uh1jhjrqubj)}(hhh]h)}(h.This is the last tag in this descriptor block.h]h.This is the last tag in this descriptor block.}(hjqhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjqubah}(h]h ]h"]h$]h&]uh1jhjrqubeh}(h]h ]h"]h$]h&]uh1j{hjpubeh}(h]h ]h"]h$]h&]uh1jhjupubeh}(h]h ]h"]h$]h&]colsKuh1jJhjrpubah}(h]h ]j,ah"]h$]h&]uh1jEhjwkhhhNhNubh)}(hIf JBD2_FEATURE_INCOMPAT_CSUM_V3 is NOT set, the journal block tag is defined as ``struct journal_block_tag_s``, which looks like the following. The size is 8, 12, 24, or 28 bytes:h](hQIf JBD2_FEATURE_INCOMPAT_CSUM_V3 is NOT set, the journal block tag is defined as }(hjqhhhNhNubj,)}(h``struct journal_block_tag_s``h]hstruct journal_block_tag_s}(hjqhhhNhNubah}(h]h ]h"]h$]h&]uh1j+hjqubhE, which looks like the following. The size is 8, 12, 24, or 28 bytes:}(hjqhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhj"VhMhjwkhhubjF)}(hhh]jK)}(hhh](jP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhjqubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhjqubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhjqubjP)}(hhh]h}(h]h ]h"]h$]h&]jZK(uh1jOhjqubjw)}(hhh]j|)}(hhh](j)}(hhh]h)}(hOffseth]hOffset}(hjrhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhj rubah}(h]h ]h"]h$]h&]uh1jhj rubj)}(hhh]h)}(hTypeh]hType}(hj&rhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhj#rubah}(h]h ]h"]h$]h&]uh1jhj rubj)}(hhh]h)}(hNameh]hName}(hj=rhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhj:rubah}(h]h ]h"]h$]h&]uh1jhj rubj)}(hhh]h)}(h Descriptorh]h Descriptor}(hjTrhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjQrubah}(h]h ]h"]h$]h&]uh1jhj rubeh}(h]h ]h"]h$]h&]uh1j{hjrubah}(h]h ]h"]h$]h&]uh1jvhjqubj)}(hhh](j|)}(hhh](j)}(hhh]h)}(h0x0h]h0x0}(hj}rhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjzrubah}(h]h ]h"]h$]h&]uh1jhjwrubj)}(hhh]h)}(h__be32h]h__be32}(hjrhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjrubah}(h]h ]h"]h$]h&]uh1jhjwrubj)}(hhh]h)}(h t_blocknrh]h t_blocknr}(hjrhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjrubah}(h]h ]h"]h$]h&]uh1jhjwrubj)}(hhh]h)}(hZLower 32-bits of the location of where the corresponding data block should end up on disk.h]hZLower 32-bits of the location of where the corresponding data block should end up on disk.}(hjrhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjrubah}(h]h ]h"]h$]h&]uh1jhjwrubeh}(h]h ]h"]h$]h&]uh1j{hjtrubj|)}(hhh](j)}(hhh]h)}(h0x4h]h0x4}(hjrhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjrubah}(h]h ]h"]h$]h&]uh1jhjrubj)}(hhh]h)}(h__be16h]h__be16}(hjrhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjrubah}(h]h ]h"]h$]h&]uh1jhjrubj)}(hhh]h)}(h t_checksumh]h t_checksum}(hjshhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhj subah}(h]h ]h"]h$]h&]uh1jhjrubj)}(hhh]h)}(hsChecksum of the journal UUID, the sequence number, and the data block. Note that only the lower 16 bits are stored.h]hsChecksum of the journal UUID, the sequence number, and the data block. Note that only the lower 16 bits are stored.}(hj'shhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhj$subah}(h]h ]h"]h$]h&]uh1jhjrubeh}(h]h ]h"]h$]h&]uh1j{hjtrubj|)}(hhh](j)}(hhh]h)}(h0x6h]h0x6}(hjGshhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjDsubah}(h]h ]h"]h$]h&]uh1jhjAsubj)}(hhh]h)}(h__be16h]h__be16}(hj^shhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhj[subah}(h]h ]h"]h$]h&]uh1jhjAsubj)}(hhh]h)}(ht_flagsh]ht_flags}(hjushhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjrsubah}(h]h ]h"]h$]h&]uh1jhjAsubj)}(hhh]h)}(hOFlags that go with the descriptor. See the table jbd2_tag_flags_ for more info.h](h1Flags that go with the descriptor. See the table }(hjshhhNhNubj)}(hjbd2_tag_flags_h]hjbd2_tag_flags}(hjshhhNhNubah}(h]h ]h"]h$]h&]namejbd2_tag_flagsjjnuh1jhjsjKubh for more info.}(hjshhhNhNubeh}(h]h ]h"]h$]h&]uh1hhj"VhMhjsubah}(h]h ]h"]h$]h&]uh1jhjAsubeh}(h]h ]h"]h$]h&]uh1j{hjtrubj|)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]uh1jhjsubj)}(hhh]h}(h]h ]h"]h$]h&]uh1jhjsubj)}(hhh]h}(h]h ]h"]h$]h&]uh1jhjsubj)}(hhh]h)}(h^This next field is only present if the super block indicates support for 64-bit block numbers.h]h^This next field is only present if the super block indicates support for 64-bit block numbers.}(hjshhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjsubah}(h]h ]h"]h$]h&]uh1jhjsubeh}(h]h ]h"]h$]h&]uh1j{hjtrubj|)}(hhh](j)}(hhh]h)}(h0x8h]h0x8}(hjshhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjsubah}(h]h ]h"]h$]h&]uh1jhjsubj)}(hhh]h)}(h__be32h]h__be32}(hjthhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjtubah}(h]h ]h"]h$]h&]uh1jhjsubj)}(hhh]h)}(ht_blocknr_highh]ht_blocknr_high}(hj)thhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhj&tubah}(h]h ]h"]h$]h&]uh1jhjsubj)}(hhh]h)}(hZUpper 32-bits of the location of where the corresponding data block should end up on disk.h]hZUpper 32-bits of the location of where the corresponding data block should end up on disk.}(hj@thhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhj=tubah}(h]h ]h"]h$]h&]uh1jhjsubeh}(h]h ]h"]h$]h&]uh1j{hjtrubj|)}(hhh](j)}(hhh]h}(h]h ]h"]h$]h&]uh1jhjZtubj)}(hhh]h}(h]h ]h"]h$]h&]uh1jhjZtubj)}(hhh]h}(h]h ]h"]h$]h&]uh1jhjZtubj)}(hhh]h)}(hThis field appears to be open coded. It always comes at the end of the tag, after t_flags or t_blocknr_high. This field is not present if the "same UUID" flag is set.h]hThis field appears to be open coded. It always comes at the end of the tag, after t_flags or t_blocknr_high. This field is not present if the “same UUID” flag is set.}(hj{thhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjxtubah}(h]h ]h"]h$]h&]uh1jhjZtubeh}(h]h ]h"]h$]h&]uh1j{hjtrubj|)}(hhh](j)}(hhh]h)}(h 0x8 or 0xCh]h 0x8 or 0xC}(hjthhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjtubah}(h]h ]h"]h$]h&]uh1jhjtubj)}(hhh]h)}(hcharh]hchar}(hjthhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjtubah}(h]h ]h"]h$]h&]uh1jhjtubj)}(hhh]h)}(huuid[16]h]huuid[16]}(hjthhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjtubah}(h]h ]h"]h$]h&]uh1jhjtubj)}(hhh]h)}(hA UUID to go with this tag. This field appears to be copied from the ``j_uuid`` field in ``struct journal_s``, but only tune2fs touches that field.h](hEA UUID to go with this tag. This field appears to be copied from the }(hjthhhNhNubj,)}(h ``j_uuid``h]hj_uuid}(hjthhhNhNubah}(h]h ]h"]h$]h&]uh1j+hjtubh field in }(hjthhhNhNubj,)}(h``struct journal_s``h]hstruct journal_s}(hjthhhNhNubah}(h]h ]h"]h$]h&]uh1j+hjtubh&, but only tune2fs touches that field.}(hjthhhNhNubeh}(h]h ]h"]h$]h&]uh1hhj"VhMhjtubah}(h]h ]h"]h$]h&]uh1jhjtubeh}(h]h ]h"]h$]h&]uh1j{hjtrubeh}(h]h ]h"]h$]h&]uh1jhjqubeh}(h]h ]h"]h$]h&]colsKuh1jJhjqubah}(h]h ]j,ah"]h$]h&]uh1jEhjwkhhhNhNubh)}(hIf JBD2_FEATURE_INCOMPAT_CSUM_V2 or JBD2_FEATURE_INCOMPAT_CSUM_V3 are set, the end of the block is a ``struct jbd2_journal_block_tail``, which looks like this:h](heIf JBD2_FEATURE_INCOMPAT_CSUM_V2 or JBD2_FEATURE_INCOMPAT_CSUM_V3 are set, the end of the block is a }(hj1uhhhNhNubj,)}(h"``struct jbd2_journal_block_tail``h]hstruct jbd2_journal_block_tail}(hj9uhhhNhNubah}(h]h ]h"]h$]h&]uh1j+hj1uubh, which looks like this:}(hj1uhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhj"VhMhjwkhhubjF)}(hhh]jK)}(hhh](jP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhjTuubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhjTuubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhjTuubjP)}(hhh]h}(h]h ]h"]h$]h&]jZK(uh1jOhjTuubjw)}(hhh]j|)}(hhh](j)}(hhh]h)}(hOffseth]hOffset}(hjuhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjuubah}(h]h ]h"]h$]h&]uh1jhj~uubj)}(hhh]h)}(hTypeh]hType}(hjuhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjuubah}(h]h ]h"]h$]h&]uh1jhj~uubj)}(hhh]h)}(hNameh]hName}(hjuhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjuubah}(h]h ]h"]h$]h&]uh1jhj~uubj)}(hhh]h)}(h Descriptorh]h Descriptor}(hjuhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjuubah}(h]h ]h"]h$]h&]uh1jhj~uubeh}(h]h ]h"]h$]h&]uh1j{hj{uubah}(h]h ]h"]h$]h&]uh1jvhjTuubj)}(hhh]j|)}(hhh](j)}(hhh]h)}(h0x0h]h0x0}(hjuhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjuubah}(h]h ]h"]h$]h&]uh1jhjuubj)}(hhh]h)}(h__be32h]h__be32}(hj vhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjvubah}(h]h ]h"]h$]h&]uh1jhjuubj)}(hhh]h)}(h t_checksumh]h t_checksum}(hj vhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjvubah}(h]h ]h"]h$]h&]uh1jhjuubj)}(hhh]h)}(hQChecksum of the journal UUID + the descriptor block, with this field set to zero.h]hQChecksum of the journal UUID + the descriptor block, with this field set to zero.}(hj7vhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhj4vubah}(h]h ]h"]h$]h&]uh1jhjuubeh}(h]h ]h"]h$]h&]uh1j{hjuubah}(h]h ]h"]h$]h&]uh1jhjTuubeh}(h]h ]h"]h$]h&]colsKuh1jJhjQuubah}(h]h ]j,ah"]h$]h&]uh1jEhjwkhhhNhNubeh}(h]descriptor-blockah ]h"]descriptor blockah$]h&]uh1hhj+Vhhhj"VhMZubh)}(hhh](h)}(h Data Blockh]h Data Block}(hjovhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjlvhhhj"VhMubh)}(hXDIn general, the data blocks being written to disk through the journal are written verbatim into the journal file after the descriptor block. However, if the first four bytes of the block match the jbd2 magic number then those four bytes are replaced with zeroes and the “escaped” flag is set in the descriptor block tag.h]hXDIn general, the data blocks being written to disk through the journal are written verbatim into the journal file after the descriptor block. However, if the first four bytes of the block match the jbd2 magic number then those four bytes are replaced with zeroes and the “escaped” flag is set in the descriptor block tag.}(hj}vhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjlvhhubeh}(h] data-blockah ]h"] data blockah$]h&]uh1hhj+Vhhhj"VhMubh)}(hhh](h)}(hRevocation Blockh]hRevocation Block}(hjvhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjvhhhj"VhMubh)}(hXgA revocation block is used to prevent replay of a block in an earlier transaction. This is used to mark blocks that were journalled at one time but are no longer journalled. Typically this happens if a metadata block is freed and re-allocated as a file data block; in this case, a journal replay after the file block was written to disk will cause corruption.h]hXgA revocation block is used to prevent replay of a block in an earlier transaction. This is used to mark blocks that were journalled at one time but are no longer journalled. Typically this happens if a metadata block is freed and re-allocated as a file data block; in this case, a journal replay after the file block was written to disk will cause corruption.}(hjvhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM hjvhhubh)}(hX**NOTE**: This mechanism is NOT used to express “this journal block is superseded by this other journal block”, as the author (djwong) mistakenly thought. Any block being added to a transaction will cause the removal of all existing revocation records for that block.h](hstrong)}(h**NOTE**h]hNOTE}(hjvhhhNhNubah}(h]h ]h"]h$]h&]uh1jvhjvubhX: This mechanism is NOT used to express “this journal block is superseded by this other journal block”, as the author (djwong) mistakenly thought. Any block being added to a transaction will cause the removal of all existing revocation records for that block.}(hjvhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhj"VhMhjvhhubh)}(hRevocation blocks are described in ``struct jbd2_journal_revoke_header_s``, are at least 16 bytes in length, but use a full block:h](h#Revocation blocks are described in }(hjvhhhNhNubj,)}(h'``struct jbd2_journal_revoke_header_s``h]h#struct jbd2_journal_revoke_header_s}(hjvhhhNhNubah}(h]h ]h"]h$]h&]uh1j+hjvubh8, are at least 16 bytes in length, but use a full block:}(hjvhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhj"VhMhjvhhubjF)}(hhh]jK)}(hhh](jP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhjvubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhjvubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhjvubjP)}(hhh]h}(h]h ]h"]h$]h&]jZK(uh1jOhjvubjw)}(hhh]j|)}(hhh](j)}(hhh]h)}(hOffseth]hOffset}(hj#whhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhj wubah}(h]h ]h"]h$]h&]uh1jhjwubj)}(hhh]h)}(hTypeh]hType}(hj:whhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhj7wubah}(h]h ]h"]h$]h&]uh1jhjwubj)}(hhh]h)}(hNameh]hName}(hjQwhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjNwubah}(h]h ]h"]h$]h&]uh1jhjwubj)}(hhh]h)}(h Descriptionh]h Description}(hjhwhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM hjewubah}(h]h ]h"]h$]h&]uh1jhjwubeh}(h]h ]h"]h$]h&]uh1j{hjwubah}(h]h ]h"]h$]h&]uh1jvhjvubj)}(hhh](j|)}(hhh](j)}(hhh]h)}(h0x0h]h0x0}(hjwhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM!hjwubah}(h]h ]h"]h$]h&]uh1jhjwubj)}(hhh]h)}(hjournal_header_th]hjournal_header_t}(hjwhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM"hjwubah}(h]h ]h"]h$]h&]uh1jhjwubj)}(hhh]h)}(hr_headerh]hr_header}(hjwhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM#hjwubah}(h]h ]h"]h$]h&]uh1jhjwubj)}(hhh]h)}(hCommon block header.h]hCommon block header.}(hjwhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM$hjwubah}(h]h ]h"]h$]h&]uh1jhjwubeh}(h]h ]h"]h$]h&]uh1j{hjwubj|)}(hhh](j)}(hhh]h)}(h0xCh]h0xC}(hjwhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM%hjwubah}(h]h ]h"]h$]h&]uh1jhjwubj)}(hhh]h)}(h__be32h]h__be32}(hj xhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM&hj xubah}(h]h ]h"]h$]h&]uh1jhjwubj)}(hhh]h)}(hr_counth]hr_count}(hj$xhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM'hj!xubah}(h]h ]h"]h$]h&]uh1jhjwubj)}(hhh]h)}(h#Number of bytes used in this block.h]h#Number of bytes used in this block.}(hj;xhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM(hj8xubah}(h]h ]h"]h$]h&]uh1jhjwubeh}(h]h ]h"]h$]h&]uh1j{hjwubj|)}(hhh](j)}(hhh]h)}(h0x10h]h0x10}(hj[xhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM)hjXxubah}(h]h ]h"]h$]h&]uh1jhjUxubj)}(hhh]h)}(h__be32 or __be64h]h__be32 or __be64}(hjrxhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM*hjoxubah}(h]h ]h"]h$]h&]uh1jhjUxubj)}(hhh]h)}(h blocks[0]h]h blocks[0]}(hjxhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM+hjxubah}(h]h ]h"]h$]h&]uh1jhjUxubj)}(hhh]h)}(hBlocks to revoke.h]hBlocks to revoke.}(hjxhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM,hjxubah}(h]h ]h"]h$]h&]uh1jhjUxubeh}(h]h ]h"]h$]h&]uh1j{hjwubeh}(h]h ]h"]h$]h&]uh1jhjvubeh}(h]h ]h"]h$]h&]colsKuh1jJhjvubah}(h]h ]j,ah"]h$]h&]uh1jEhjvhhhNhNubh)}(hAfter r_count is a linear array of block numbers that are effectively revoked by this transaction. The size of each block number is 8 bytes if the superblock advertises 64-bit block number support, or 4 bytes otherwise.h]hAfter r_count is a linear array of block numbers that are effectively revoked by this transaction. The size of each block number is 8 bytes if the superblock advertises 64-bit block number support, or 4 bytes otherwise.}(hjxhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM.hjvhhubh)}(hIf JBD2_FEATURE_INCOMPAT_CSUM_V2 or JBD2_FEATURE_INCOMPAT_CSUM_V3 are set, the end of the revocation block is a ``struct jbd2_journal_revoke_tail``, which has this format:h](hpIf JBD2_FEATURE_INCOMPAT_CSUM_V2 or JBD2_FEATURE_INCOMPAT_CSUM_V3 are set, the end of the revocation block is a }(hjxhhhNhNubj,)}(h#``struct jbd2_journal_revoke_tail``h]hstruct jbd2_journal_revoke_tail}(hjxhhhNhNubah}(h]h ]h"]h$]h&]uh1j+hjxubh, which has this format:}(hjxhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhj"VhM3hjvhhubjF)}(hhh]jK)}(hhh](jP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhjxubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhjxubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhjxubjP)}(hhh]h}(h]h ]h"]h$]h&]jZK(uh1jOhjxubjw)}(hhh]j|)}(hhh](j)}(hhh]h)}(hOffseth]hOffset}(hj.yhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM;hj+yubah}(h]h ]h"]h$]h&]uh1jhj(yubj)}(hhh]h)}(hTypeh]hType}(hjEyhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM<hjByubah}(h]h ]h"]h$]h&]uh1jhj(yubj)}(hhh]h)}(hNameh]hName}(hj\yhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM=hjYyubah}(h]h ]h"]h$]h&]uh1jhj(yubj)}(hhh]h)}(h Descriptionh]h Description}(hjsyhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM>hjpyubah}(h]h ]h"]h$]h&]uh1jhj(yubeh}(h]h ]h"]h$]h&]uh1j{hj%yubah}(h]h ]h"]h$]h&]uh1jvhjxubj)}(hhh]j|)}(hhh](j)}(hhh]h)}(h0x0h]h0x0}(hjyhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM?hjyubah}(h]h ]h"]h$]h&]uh1jhjyubj)}(hhh]h)}(h__be32h]h__be32}(hjyhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM@hjyubah}(h]h ]h"]h$]h&]uh1jhjyubj)}(hhh]h)}(h r_checksumh]h r_checksum}(hjyhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMAhjyubah}(h]h ]h"]h$]h&]uh1jhjyubj)}(hhh]h)}(h/Checksum of the journal UUID + revocation blockh]h/Checksum of the journal UUID + revocation block}(hjyhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMBhjyubah}(h]h ]h"]h$]h&]uh1jhjyubeh}(h]h ]h"]h$]h&]uh1j{hjyubah}(h]h ]h"]h$]h&]uh1jhjxubeh}(h]h ]h"]h$]h&]colsKuh1jJhjxubah}(h]h ]j,ah"]h$]h&]uh1jEhjvhhhNhNubeh}(h]revocation-blockah ]h"]revocation blockah$]h&]uh1hhj+Vhhhj"VhMubh)}(hhh](h)}(h Commit Blockh]h Commit Block}(hjzhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjzhhhj"VhMEubh)}(hThe commit block is a sentry that indicates that a transaction has been completely written to the journal. Once this commit block reaches the journal, the data stored with this transaction can be written to their final locations on disk.h]hThe commit block is a sentry that indicates that a transaction has been completely written to the journal. Once this commit block reaches the journal, the data stored with this transaction can be written to their final locations on disk.}(hj'zhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMGhjzhhubh)}(hjThe commit block is described by ``struct commit_header``, which is 32 bytes long (but uses a full block):h](h!The commit block is described by }(hj5zhhhNhNubj,)}(h``struct commit_header``h]hstruct commit_header}(hj=zhhhNhNubah}(h]h ]h"]h$]h&]uh1j+hj5zubh1, which is 32 bytes long (but uses a full block):}(hj5zhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhj"VhMLhjzhhubjF)}(hhh]jK)}(hhh](jP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhjXzubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhjXzubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhjXzubjP)}(hhh]h}(h]h ]h"]h$]h&]jZK(uh1jOhjXzubjw)}(hhh]j|)}(hhh](j)}(hhh]h)}(hOffseth]hOffset}(hjzhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMShjzubah}(h]h ]h"]h$]h&]uh1jhjzubj)}(hhh]h)}(hTypeh]hType}(hjzhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMThjzubah}(h]h ]h"]h$]h&]uh1jhjzubj)}(hhh]h)}(hNameh]hName}(hjzhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMUhjzubah}(h]h ]h"]h$]h&]uh1jhjzubj)}(hhh]h)}(h Descriptorh]h Descriptor}(hjzhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMVhjzubah}(h]h ]h"]h$]h&]uh1jhjzubeh}(h]h ]h"]h$]h&]uh1j{hjzubah}(h]h ]h"]h$]h&]uh1jvhjXzubj)}(hhh](j|)}(hhh](j)}(hhh]h)}(h0x0h]h0x0}(hjzhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMWhjzubah}(h]h ]h"]h$]h&]uh1jhjzubj)}(hhh]h)}(hjournal_header_sh]hjournal_header_s}(hj {hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMXhj {ubah}(h]h ]h"]h$]h&]uh1jhjzubj)}(hhh]h)}(h (open coded)h]h (open coded)}(hj${hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMYhj!{ubah}(h]h ]h"]h$]h&]uh1jhjzubj)}(hhh]h)}(hCommon block header.h]hCommon block header.}(hj;{hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMZhj8{ubah}(h]h ]h"]h$]h&]uh1jhjzubeh}(h]h ]h"]h$]h&]uh1j{hjzubj|)}(hhh](j)}(hhh]h)}(h0xCh]h0xC}(hj[{hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM[hjX{ubah}(h]h ]h"]h$]h&]uh1jhjU{ubj)}(hhh]h)}(h unsigned charh]h unsigned char}(hjr{hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM\hjo{ubah}(h]h ]h"]h$]h&]uh1jhjU{ubj)}(hhh]h)}(h h_chksum_typeh]h h_chksum_type}(hj{hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM]hj{ubah}(h]h ]h"]h$]h&]uh1jhjU{ubj)}(hhh]h)}(hThe type of checksum to use to verify the integrity of the data blocks in the transaction. See jbd2_checksum_type_ for more info.h](h_The type of checksum to use to verify the integrity of the data blocks in the transaction. See }(hj{hhhNhNubj)}(hjbd2_checksum_type_h]hjbd2_checksum_type}(hj{hhhNhNubah}(h]h ]h"]h$]h&]namejbd2_checksum_typejjeuh1jhj{jKubh for more info.}(hj{hhhNhNubeh}(h]h ]h"]h$]h&]uh1hhj"VhM^hj{ubah}(h]h ]h"]h$]h&]uh1jhjU{ubeh}(h]h ]h"]h$]h&]uh1j{hjzubj|)}(hhh](j)}(hhh]h)}(h0xDh]h0xD}(hj{hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhM`hj{ubah}(h]h ]h"]h$]h&]uh1jhj{ubj)}(hhh]h)}(h unsigned charh]h unsigned char}(hj{hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMahj{ubah}(h]h ]h"]h$]h&]uh1jhj{ubj)}(hhh]h)}(h h_chksum_sizeh]h h_chksum_size}(hj|hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMbhj{ubah}(h]h ]h"]h$]h&]uh1jhj{ubj)}(hhh]h)}(h8The number of bytes used by the checksum. Most likely 4.h]h8The number of bytes used by the checksum. Most likely 4.}(hj|hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMchj|ubah}(h]h ]h"]h$]h&]uh1jhj{ubeh}(h]h ]h"]h$]h&]uh1j{hjzubj|)}(hhh](j)}(hhh]h)}(h0xEh]h0xE}(hj9|hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMdhj6|ubah}(h]h ]h"]h$]h&]uh1jhj3|ubj)}(hhh]h)}(h unsigned charh]h unsigned char}(hjP|hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMehjM|ubah}(h]h ]h"]h$]h&]uh1jhj3|ubj)}(hhh]h)}(h h_padding[2]h]h h_padding[2]}(hjg|hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMfhjd|ubah}(h]h ]h"]h$]h&]uh1jhj3|ubj)}(hhh]h}(h]h ]h"]h$]h&]uh1jhj3|ubeh}(h]h ]h"]h$]h&]uh1j{hjzubj|)}(hhh](j)}(hhh]h)}(h0x10h]h0x10}(hj|hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhhj|ubah}(h]h ]h"]h$]h&]uh1jhj|ubj)}(hhh]h)}(h__be32h]h__be32}(hj|hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMihj|ubah}(h]h ]h"]h$]h&]uh1jhj|ubj)}(hhh]h)}(hh_chksum[JBD2_CHECKSUM_BYTES]h]hh_chksum[JBD2_CHECKSUM_BYTES]}(hj|hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMjhj|ubah}(h]h ]h"]h$]h&]uh1jhj|ubj)}(hhh]h)}(hX^32 bytes of space to store checksums. If JBD2_FEATURE_INCOMPAT_CSUM_V2 or JBD2_FEATURE_INCOMPAT_CSUM_V3 are set, the first ``__be32`` is the checksum of the journal UUID and the entire commit block, with this field zeroed. If JBD2_FEATURE_COMPAT_CHECKSUM is set, the first ``__be32`` is the crc32 of all the blocks already written to the transaction.h](h{32 bytes of space to store checksums. If JBD2_FEATURE_INCOMPAT_CSUM_V2 or JBD2_FEATURE_INCOMPAT_CSUM_V3 are set, the first }(hj|hhhNhNubj,)}(h ``__be32``h]h__be32}(hj|hhhNhNubah}(h]h ]h"]h$]h&]uh1j+hj|ubh is the checksum of the journal UUID and the entire commit block, with this field zeroed. If JBD2_FEATURE_COMPAT_CHECKSUM is set, the first }(hj|hhhNhNubj,)}(h ``__be32``h]h__be32}(hj|hhhNhNubah}(h]h ]h"]h$]h&]uh1j+hj|ubhC is the crc32 of all the blocks already written to the transaction.}(hj|hhhNhNubeh}(h]h ]h"]h$]h&]uh1hhj"VhMkhj|ubah}(h]h ]h"]h$]h&]uh1jhj|ubeh}(h]h ]h"]h$]h&]uh1j{hjzubj|)}(hhh](j)}(hhh]h)}(h0x30h]h0x30}(hj}hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMqhj}ubah}(h]h ]h"]h$]h&]uh1jhj}ubj)}(hhh]h)}(h__be64h]h__be64}(hj0}hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMrhj-}ubah}(h]h ]h"]h$]h&]uh1jhj}ubj)}(hhh]h)}(h h_commit_sech]h h_commit_sec}(hjG}hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMshjD}ubah}(h]h ]h"]h$]h&]uh1jhj}ubj)}(hhh]h)}(hHThe time that the transaction was committed, in seconds since the epoch.h]hHThe time that the transaction was committed, in seconds since the epoch.}(hj^}hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMthj[}ubah}(h]h ]h"]h$]h&]uh1jhj}ubeh}(h]h ]h"]h$]h&]uh1j{hjzubj|)}(hhh](j)}(hhh]h)}(h0x38h]h0x38}(hj~}hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMuhj{}ubah}(h]h ]h"]h$]h&]uh1jhjx}ubj)}(hhh]h)}(h__be32h]h__be32}(hj}hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMvhj}ubah}(h]h ]h"]h$]h&]uh1jhjx}ubj)}(hhh]h)}(h h_commit_nsech]h h_commit_nsec}(hj}hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMwhj}ubah}(h]h ]h"]h$]h&]uh1jhjx}ubj)}(hhh]h)}(h-Nanoseconds component of the above timestamp.h]h-Nanoseconds component of the above timestamp.}(hj}hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMxhj}ubah}(h]h ]h"]h$]h&]uh1jhjx}ubeh}(h]h ]h"]h$]h&]uh1j{hjzubeh}(h]h ]h"]h$]h&]uh1jhjXzubeh}(h]h ]h"]h$]h&]colsKuh1jJhjUzubah}(h]h ]j,ah"]h$]h&]uh1jEhjzhhhNhNubeh}(h] commit-blockah ]h"] commit blockah$]h&]uh1hhj+Vhhhj"VhMEubh)}(hhh](h)}(h Fast commitsh]h Fast commits}(hj}hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj}hhhj"VhM{ubh)}(hXFast commit area is organized as a log of tag length values. Each TLV has a ``struct ext4_fc_tl`` in the beginning which stores the tag and the length of the entire field. It is followed by variable length tag specific value. Here is the list of supported tags and their meanings:h](hLFast commit area is organized as a log of tag length values. Each TLV has a }(hj ~hhhNhNubj,)}(h``struct ext4_fc_tl``h]hstruct ext4_fc_tl}(hj~hhhNhNubah}(h]h ]h"]h$]h&]uh1j+hj ~ubh in the beginning which stores the tag and the length of the entire field. It is followed by variable length tag specific value. Here is the list of supported tags and their meanings:}(hj ~hhhNhNubeh}(h]h ]h"]h$]h&]uh1hhj"VhM}hj}hhubjF)}(hhh]jK)}(hhh](jP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhj,~ubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhj,~ubjP)}(hhh]h}(h]h ]h"]h$]h&]jZKuh1jOhj,~ubjP)}(hhh]h}(h]h ]h"]h$]h&]jZK uh1jOhj,~ubjw)}(hhh]j|)}(hhh](j)}(hhh]h)}(hTagh]hTag}(hj\~hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjY~ubah}(h]h ]h"]h$]h&]uh1jhjV~ubj)}(hhh]h)}(hMeaningh]hMeaning}(hjs~hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjp~ubah}(h]h ]h"]h$]h&]uh1jhjV~ubj)}(hhh]h)}(h Value structh]h Value struct}(hj~hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhj~ubah}(h]h ]h"]h$]h&]uh1jhjV~ubj)}(hhh]h)}(h Descriptionh]h Description}(hj~hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhj~ubah}(h]h ]h"]h$]h&]uh1jhjV~ubeh}(h]h ]h"]h$]h&]uh1j{hjS~ubah}(h]h ]h"]h$]h&]uh1jvhj,~ubj)}(hhh](j|)}(hhh](j)}(hhh]h)}(hEXT4_FC_TAG_HEADh]hEXT4_FC_TAG_HEAD}(hj~hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhj~ubah}(h]h ]h"]h$]h&]uh1jhj~ubj)}(hhh]h)}(hFast commit area headerh]hFast commit area header}(hj~hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhj~ubah}(h]h ]h"]h$]h&]uh1jhj~ubj)}(hhh]h)}(h``struct ext4_fc_head``h]j,)}(hj~h]hstruct ext4_fc_head}(hj~hhhNhNubah}(h]h ]h"]h$]h&]uh1j+hj~ubah}(h]h ]h"]h$]h&]uh1hhj"VhMhj~ubah}(h]h ]h"]h$]h&]uh1jhj~ubj)}(hhh]h)}(hSStores the TID of the transaction after which these fast commits should be applied.h]hSStores the TID of the transaction after which these fast commits should be applied.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjubah}(h]h ]h"]h$]h&]uh1jhj~ubeh}(h]h ]h"]h$]h&]uh1j{hj~ubj|)}(hhh](j)}(hhh]h)}(hEXT4_FC_TAG_ADD_RANGEh]hEXT4_FC_TAG_ADD_RANGE}(hj8hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhj5ubah}(h]h ]h"]h$]h&]uh1jhj2ubj)}(hhh]h)}(hAdd extent to inodeh]hAdd extent to inode}(hjOhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjLubah}(h]h ]h"]h$]h&]uh1jhj2ubj)}(hhh]h)}(h``struct ext4_fc_add_range``h]j,)}(hjhh]hstruct ext4_fc_add_range}(hjjhhhNhNubah}(h]h ]h"]h$]h&]uh1j+hjfubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjcubah}(h]h ]h"]h$]h&]uh1jhj2ubj)}(hhh]h)}(hhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhj;ubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]uh1j{hj~ubj|)}(hhh](j)}(hhh]h)}(hEXT4_FC_TAG_PADh]hEXT4_FC_TAG_PAD}(hj^hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhj[ubah}(h]h ]h"]h$]h&]uh1jhjXubj)}(hhh]h)}(hPadding (unused area)h]hPadding (unused area)}(hjuhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjrubah}(h]h ]h"]h$]h&]uh1jhjXubj)}(hhh]h)}(hNoneh]hNone}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjubah}(h]h ]h"]h$]h&]uh1jhjXubj)}(hhh]h)}(h%Unused bytes in the fast commit area.h]h%Unused bytes in the fast commit area.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjubah}(h]h ]h"]h$]h&]uh1jhjXubeh}(h]h ]h"]h$]h&]uh1j{hj~ubj|)}(hhh](j)}(hhh]h)}(hEXT4_FC_TAG_TAILh]hEXT4_FC_TAG_TAIL}(hjÁhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hMark the end of a fast commith]hMark the end of a fast commit}(hjځhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjׁubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h``struct ext4_fc_tail``h]j,)}(hjh]hstruct ext4_fc_tail}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1j+hjubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h\Stores the TID of the commit, CRC of the fast commit of which this tag represents the end ofh]h\Stores the TID of the commit, CRC of the fast commit of which this tag represents the end of}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]uh1j{hj~ubeh}(h]h ]h"]h$]h&]uh1jhj,~ubeh}(h]h ]h"]h$]h&]colsKuh1jJhj)~ubah}(h]h ]j,ah"]h$]h&]uh1jEhj}hhhNhNubeh}(h] fast-commitsah ]h"] fast commitsah$]h&]uh1hhj+Vhhhj"VhM{ubh)}(hhh](h)}(hFast Commit Replay Idempotenceh]hFast Commit Replay Idempotence}(hjIhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjFhhhj"VhMubh)}(hFast commits tags are idempotent in nature provided the recovery code follows certain rules. The guiding principle that the commit path follows while committing is that it stores the result of a particular operation instead of storing the procedure.h]hFast commits tags are idempotent in nature provided the recovery code follows certain rules. The guiding principle that the commit path follows while committing is that it stores the result of a particular operation instead of storing the procedure.}(hjWhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjFhhubh)}(hXLet's consider this rename operation: 'mv /a /b'. Let's assume dirent '/a' was associated with inode 10. During fast commit, instead of storing this operation as a procedure "rename a to b", we store the resulting file system state as a "series" of outcomes:h]hXLet’s consider this rename operation: ‘mv /a /b’. Let’s assume dirent ‘/a’ was associated with inode 10. During fast commit, instead of storing this operation as a procedure “rename a to b”, we store the resulting file system state as a “series” of outcomes:}(hjehhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjFhhubh bullet_list)}(hhh](h list_item)}(hLink dirent b to inode 10h]h)}(hj|h]hLink dirent b to inode 10}(hj~hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjzubah}(h]h ]h"]h$]h&]uh1jxhjuhhhj"VhNubjy)}(hUnlink dirent ah]h)}(hjh]hUnlink dirent a}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjubah}(h]h ]h"]h$]h&]uh1jxhjuhhhj"VhNubjy)}(hInode 10 with valid refcount h]h)}(hInode 10 with valid refcounth]hInode 10 with valid refcount}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjubah}(h]h ]h"]h$]h&]uh1jxhjuhhhj"VhNubeh}(h]h ]h"]h$]h&]bullet-uh1jshj"VhMhjFhhubh)}(hNow when recovery code runs, it needs "enforce" this state on the file system. This is what guarantees idempotence of fast commit replay.h]hNow when recovery code runs, it needs “enforce” this state on the file system. This is what guarantees idempotence of fast commit replay.}(hjȂhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjFhhubh)}(hLet's take an example of a procedure that is not idempotent and see how fast commits make it idempotent. Consider following sequence of operations:h]hLet’s take an example of a procedure that is not idempotent and see how fast commits make it idempotent. Consider following sequence of operations:}(hjւhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjFhhubhenumerated_list)}(hhh](jy)}(hrm Ah]h)}(hjh]hrm A}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjubah}(h]h ]h"]h$]h&]uh1jxhjhhhj"VhNubjy)}(hmv B Ah]h)}(hjh]hmv B A}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjubah}(h]h ]h"]h$]h&]uh1jxhjhhhj"VhNubjy)}(hread A h]h)}(hread Ah]hread A}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjubah}(h]h ]h"]h$]h&]uh1jxhjhhhj"VhNubeh}(h]h ]h"]h$]h&]enumtypearabicprefixhsuffix)uh1jhjFhhhj"VhMubh)}(hXIf we store this sequence of operations as is then the replay is not idempotent. Let's say while in replay, we crash after (2). During the second replay, file A (which was actually created as a result of "mv B A" operation) would get deleted. Thus, file named A would be absent when we try to read A. So, this sequence of operations is not idempotent. However, as mentioned above, instead of storing the procedure fast commits store the outcome of each procedure. Thus the fast commit log for above procedure would be as follows:h]hXIf we store this sequence of operations as is then the replay is not idempotent. Let’s say while in replay, we crash after (2). During the second replay, file A (which was actually created as a result of “mv B A” operation) would get deleted. Thus, file named A would be absent when we try to read A. So, this sequence of operations is not idempotent. However, as mentioned above, instead of storing the procedure fast commits store the outcome of each procedure. Thus the fast commit log for above procedure would be as follows:}(hj:hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjFhhubh)}(hd(Let's assume dirent A was linked to inode 10 and dirent B was linked to inode 11 before the replay)h]hf(Let’s assume dirent A was linked to inode 10 and dirent B was linked to inode 11 before the replay)}(hjHhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjFhhubj)}(hhh](jy)}(hUnlink Ah]h)}(hj[h]hUnlink A}(hj]hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjYubah}(h]h ]h"]h$]h&]uh1jxhjVhhhj"VhNubjy)}(hLink A to inode 11h]h)}(hjrh]hLink A to inode 11}(hjthhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjpubah}(h]h ]h"]h$]h&]uh1jxhjVhhhj"VhNubjy)}(hUnlink Bh]h)}(hjh]hUnlink B}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjubah}(h]h ]h"]h$]h&]uh1jxhjVhhhj"VhNubjy)}(h Inode 11 h]h)}(hInode 11h]hInode 11}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjubah}(h]h ]h"]h$]h&]uh1jxhjVhhhj"VhNubeh}(h]h ]h"]h$]h&]j5j6j7hj8j9uh1jhjFhhhj"VhMubh)}(hXIf we crash after (3) we will have file A linked to inode 11. During the second replay, we will remove file A (inode 11). But we will create it back and make it point to inode 11. We won't find B, so we'll just skip that step. At this point, the refcount for inode 11 is not reliable, but that gets fixed by the replay of last inode 11 tag. Thus, by converting a non-idempotent procedure into a series of idempotent outcomes, fast commits ensured idempotence during the replay.h]hXIf we crash after (3) we will have file A linked to inode 11. During the second replay, we will remove file A (inode 11). But we will create it back and make it point to inode 11. We won’t find B, so we’ll just skip that step. At this point, the refcount for inode 11 is not reliable, but that gets fixed by the replay of last inode 11 tag. Thus, by converting a non-idempotent procedure into a series of idempotent outcomes, fast commits ensured idempotence during the replay.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhjFhhubeh}(h]fast-commit-replay-idempotenceah ]h"]fast commit replay idempotenceah$]h&]uh1hhj+Vhhhj"VhMubh)}(hhh](h)}(hJournal Checkpointh]hJournal Checkpoint}(hjՃhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj҃hhhj"VhMubh)}(hXWCheckpointing the journal ensures all transactions and their associated buffers are submitted to the disk. In-progress transactions are waited upon and included in the checkpoint. Checkpointing is used internally during critical updates to the filesystem including journal recovery, filesystem resizing, and freeing of the journal_t structure.h]hXWCheckpointing the journal ensures all transactions and their associated buffers are submitted to the disk. In-progress transactions are waited upon and included in the checkpoint. Checkpointing is used internally during critical updates to the filesystem including journal recovery, filesystem resizing, and freeing of the journal_t structure.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhj҃hhubh)}(hXA journal checkpoint can be triggered from userspace via the ioctl EXT4_IOC_CHECKPOINT. This ioctl takes a single, u64 argument for flags. Currently, three flags are supported. First, EXT4_IOC_CHECKPOINT_FLAG_DRY_RUN can be used to verify input to the ioctl. It returns error if there is any invalid input, otherwise it returns success without performing any checkpointing. This can be used to check whether the ioctl exists on a system and to verify there are no issues with arguments or flags. The other two flags are EXT4_IOC_CHECKPOINT_FLAG_DISCARD and EXT4_IOC_CHECKPOINT_FLAG_ZEROOUT. These flags cause the journal blocks to be discarded or zero-filled, respectively, after the journal checkpoint is complete. EXT4_IOC_CHECKPOINT_FLAG_DISCARD and EXT4_IOC_CHECKPOINT_FLAG_ZEROOUT cannot both be set. The ioctl may be useful when snapshotting a system or for complying with content deletion SLOs.l3h]hXA journal checkpoint can be triggered from userspace via the ioctl EXT4_IOC_CHECKPOINT. This ioctl takes a single, u64 argument for flags. Currently, three flags are supported. First, EXT4_IOC_CHECKPOINT_FLAG_DRY_RUN can be used to verify input to the ioctl. It returns error if there is any invalid input, otherwise it returns success without performing any checkpointing. This can be used to check whether the ioctl exists on a system and to verify there are no issues with arguments or flags. The other two flags are EXT4_IOC_CHECKPOINT_FLAG_DISCARD and EXT4_IOC_CHECKPOINT_FLAG_ZEROOUT. These flags cause the journal blocks to be discarded or zero-filled, respectively, after the journal checkpoint is complete. EXT4_IOC_CHECKPOINT_FLAG_DISCARD and EXT4_IOC_CHECKPOINT_FLAG_ZEROOUT cannot both be set. The ioctl may be useful when snapshotting a system or for complying with content deletion SLOs.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj"VhMhj҃hhubh)}(h SPDX-License-Identifier: GPL-2.0h]h SPDX-License-Identifier: GPL-2.0}hjsbah}(h]h ]h"]h$]h&]hhuh1hhj҃hhh)Documentation/filesystems/ext4/orphan.rsthKubeh}(h]journal-checkpointah ]h"]journal checkpointah$]h&]uh1hhj+Vhhhj"VhMubeh}(h] journal-jbd2ah ]h"]journal (jbd2)ah$]h&]uh1hhhhhhj"VhKubh)}(hhh](h)}(h Orphan fileh]h Orphan file}(hj!hhhNhNubah}(h]h ]h"]h$]h&]uh1hhjhhhj hKubh)}(hXIn unix there can inodes that are unlinked from directory hierarchy but that are still alive because they are open. In case of crash the filesystem has to clean up these inodes as otherwise they (and the blocks referenced from them) would leak. Similarly if we truncate or extend the file, we need not be able to perform the operation in a single journalling transaction. In such case we track the inode as orphan so that in case of crash extra blocks allocated to the file get truncated.h]hXIn unix there can inodes that are unlinked from directory hierarchy but that are still alive because they are open. In case of crash the filesystem has to clean up these inodes as otherwise they (and the blocks referenced from them) would leak. Similarly if we truncate or extend the file, we need not be able to perform the operation in a single journalling transaction. In such case we track the inode as orphan so that in case of crash extra blocks allocated to the file get truncated.}(hj/hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj hKhjhhubh)}(hXxTraditionally ext4 tracks orphan inodes in a form of single linked list where superblock contains the inode number of the last orphan inode (s_last_orphan field) and then each inode contains inode number of the previously orphaned inode (we overload i_dtime inode field for this). However this filesystem global single linked list is a scalability bottleneck for workloads that result in heavy creation of orphan inodes. When orphan file feature (COMPAT_ORPHAN_FILE) is enabled, the filesystem has a special inode (referenced from the superblock through s_orphan_file_inum) with several blocks. Each of these blocks has a structure:h]hXxTraditionally ext4 tracks orphan inodes in a form of single linked list where superblock contains the inode number of the last orphan inode (s_last_orphan field) and then each inode contains inode number of the previously orphaned inode (we overload i_dtime inode field for this). However this filesystem global single linked list is a scalability bottleneck for workloads that result in heavy creation of orphan inodes. When orphan file feature (COMPAT_ORPHAN_FILE) is enabled, the filesystem has a special inode (referenced from the superblock through s_orphan_file_inum) with several blocks. Each of these blocks has a structure:}(hj=hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj hKhjhhubjF)}(hhh]jK)}(hhh](jP)}(hhh]h}(h]h ]h"]h$]h&]colwidthK uh1jOhjNubjP)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jOhjNubjP)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jOhjNubjP)}(hhh]h}(h]h ]h"]h$]h&]colwidthKuh1jOhjNubjw)}(hhh]j|)}(hhh](j)}(hhh]h)}(hOffseth]hOffset}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj hKhjubah}(h]h ]h"]h$]h&]uh1jhj|ubj)}(hhh]h)}(hTypeh]hType}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj hKhjubah}(h]h ]h"]h$]h&]uh1jhj|ubj)}(hhh]h)}(hNameh]hName}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj hKhjubah}(h]h ]h"]h$]h&]uh1jhj|ubj)}(hhh]h)}(h Descriptionh]h Description}(hjDŽhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj hKhjĄubah}(h]h ]h"]h$]h&]uh1jhj|ubeh}(h]h ]h"]h$]h&]uh1j{hjyubah}(h]h ]h"]h$]h&]uh1jvhjNubj)}(hhh](j|)}(hhh](j)}(hhh]h)}(h0x0h]h0x0}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj hKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hArray of __le32 entriesh]hArray of __le32 entries}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj hKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hOrphan inode entriesh]hOrphan inode entries}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj hKhjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hUEach __le32 entry is either empty (0) or it contains inode number of an orphan inode.h]hUEach __le32 entry is either empty (0) or it contains inode number of an orphan inode.}(hj5hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj hKhj2ubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h blocksize-8h]h blocksize-8}(hjUhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj hKhjRubah}(h]h ]h"]h$]h&]uh1jhjOubj)}(hhh]h)}(h__le32h]h__le32}(hjlhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj hKhjiubah}(h]h ]h"]h$]h&]uh1jhjOubj)}(hhh]h)}(hob_magich]hob_magic}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj hKhjubah}(h]h ]h"]h$]h&]uh1jhjOubj)}(hhh]h)}(h4Magic value stored in orphan block tail (0x0b10ca04)h]h4Magic value stored in orphan block tail (0x0b10ca04)}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj hKhjubah}(h]h ]h"]h$]h&]uh1jhjOubeh}(h]h ]h"]h$]h&]uh1j{hjubj|)}(hhh](j)}(hhh]h)}(h blocksize-4h]h blocksize-4}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj hK!hjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h__le32h]h__le32}(hjхhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj hK!hj΅ubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(h ob_checksumh]h ob_checksum}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj hK!hjubah}(h]h ]h"]h$]h&]uh1jhjubj)}(hhh]h)}(hChecksum of the orphan block.h]hChecksum of the orphan block.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhj hK!hjubah}(h]h ]h"]h$]h&]uh1jhjubeh}(h]h ]h"]h$]h&]uh1j{hjubeh}(h]h ]h"]h$]h&]uh1jhjNubeh}(h]h ]h"]h$]h&]colsKuh1jJhjKubah}(h]h ]h"]h$]h&]uh1jEhjhhhj hNubh)}(hXWhen a filesystem with orphan file feature is writeably mounted, we set RO_COMPAT_ORPHAN_PRESENT feature in the superblock to indicate there may be valid orphan entries. In case we see this feature when mounting the filesystem, we read the whole orphan file and process all orphan inodes found there as usual. When cleanly unmounting the filesystem we remove the RO_COMPAT_ORPHAN_PRESENT feature to avoid unnecessary scanning of the orphan file and also make the filesystem fully compatible with older kernels.h]hXWhen a filesystem with orphan file feature is writeably mounted, we set RO_COMPAT_ORPHAN_PRESENT feature in the superblock to indicate there may be valid orphan entries. In case we see this feature when mounting the filesystem, we read the whole orphan file and process all orphan inodes found there as usual. When cleanly unmounting the filesystem we remove the RO_COMPAT_ORPHAN_PRESENT feature to avoid unnecessary scanning of the orphan file and also make the filesystem fully compatible with older kernels.}(hj,hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj hK$hjhhubeh}(h] orphan-fileah ]h"] orphan fileah$]h&]uh1hhhhhhj hKubeh}(h]global-structuresah ]h"]global structuresah$]h&]uh1hhhhhhhhKubeh}(h]h ]h"]h$]h&]sourcehuh1hcurrent_sourceN current_lineNsettingsdocutils.frontendValues)}(hN generatorN datestampN source_linkN source_urlN toc_backlinksjfootnote_backlinksK sectnum_xformKstrip_commentsNstrip_elements_with_classesN strip_classesN report_levelK halt_levelKexit_status_levelKdebugNwarning_streamN tracebackinput_encoding utf-8-siginput_encoding_error_handlerstrictoutput_encodingutf-8output_encoding_error_handlerjlerror_encodingutf-8error_encoding_error_handlerbackslashreplace language_codeenrecord_dependenciesNconfigN id_prefixhauto_id_prefixid dump_settingsNdump_internalsNdump_transformsNdump_pseudo_xmlNexpose_internalsNstrict_visitorN_disable_configN_sourceh _destinationN _config_files]7/var/lib/git/docbuild/linux/Documentation/docutils.confafile_insertion_enabled raw_enabledKline_length_limitM'pep_referencesN pep_base_urlhttps://peps.python.org/pep_file_url_templatepep-%04drfc_referencesN rfc_base_url&https://datatracker.ietf.org/doc/html/ tab_widthKtrim_footnote_reference_spacesyntax_highlightlong smart_quotessmartquotes_locales]character_level_inline_markupdoctitle_xform docinfo_xformKsectsubtitle_xform image_loadinglinkembed_stylesheetcloak_email_addressessection_self_linkenvNubreporterNindirect_targets]substitution_defs}substitution_names}refnames}( super_state]ja super_errors]j a super_creator]j asuper_revision]j3 a super_compat]j asuper_incompat]jwasuper_rocompat]jasuper_def_hash]jasuper_mountopts]ja super_flags]ja super_encrypt]j.&abgflags]jHajbd2_blocktype]jZa jbd2_compat]jaa jbd2_incompat]j(bajbd2_checksum_type](jej{ejbd2_tag_flags](jnjseurefids}(j]j-aj ]j5.aj ]jc/ajC ]j0aj ]j2aj]j.5aj]j8aj]j<aj']j>aj]jBaj>&]jNCajH]jOajZ]jm[aja]j|gaj8b]j&jPjPjOjHjEQjBQj{QjxQj(Vj%VjjjWjWjGYjDYj ]j]j[jZjgjajRhj8bj%jjejivjfvjmpjnjvjvjzjzj}j}jCj@jσj̃jjj?j<u nametypes}(jGjj-jK.jy/j1j'2jD5j9j"=j?j6BjvCjPjOjEQj{Qj(VjjWjGYj ]j[jgjRhj%jjivjmpjvjzj}jCjσjj?uh}(jDhjDhjj-j j?.j jm/jC j1j j2jj85jj8jj=j'j>jjBj>&jXCjPjDjHjOjBQjPjxQjHQj%Vj~Qjj+VjWjVjDYjWj]jJYjZjw[jrkj ]jajgj8bjFhjejjjfvjwkjnjapjvjlvjzjvj}jzj@j}j̃jFjj҃j<ju footnote_refs} citation_refs} autofootnotes]autofootnote_refs]symbol_footnotes]symbol_footnote_refs] footnotes] citations]autofootnote_startKsymbol_footnote_startK id_counter collectionsCounter}jzKsRparse_messages]hsystem_message)}(hhh]h)}(h.Duplicate implicit target name: "super block".h]h2Duplicate implicit target name: “super block”.}(hjhhhNhNubah}(h]h ]h"]h$]h&]uh1hhjubah}(h]h ]h"]h$]h&]jrkalevelKtypeINFOsourcej"VlineKuh1jhj ]hhhj"VhKubatransform_messages] transformerN include_log]*Documentation/filesystems/ext4/globals.rst(NNNNta decorationNhhub.