56 Commits
Author SHA1 Message Date
Daniel TangandTheodore Ts'o 39fc6d4d35 Documentation: ext4: Document casefold and encrypt flags
Based on ext4(5) and fs/ext4/ext4.h.

For INCOMPAT_ENCRYPT, it's possible to create a new filesystem with that
flag without creating any encrypted inodes. ext4(5) says it adds
"support" but doesn't say whether anything's actually present like
COMPAT_RESIZE_INODE does.

Signed-off-by: Daniel Tang <danielzgtg.opensource@gmail.com>
Message-ID: <4506189.9SDvczpPoe@daniel-desktop3>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-11-26 17:13:34 -05:00
Linus Torvalds 66f8e4df00 Merge tag 'ext4_for_linus-6.18-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 bug fixes from Ted Ts'o:

 - Fix regression caused by removing CONFIG_EXT3_FS when testing some
   very old defconfigs

 - Avoid a BUG_ON when opening a file on a maliciously corrupted file
   system

 - Avoid mm warnings when freeing a very large orphan file metadata

 - Avoid a theoretical races between metadata writeback and checkpoints
   (it's very hard to hit in practice, since the race requires that the
   writeback take a very long time)

* tag 'ext4_for_linus-6.18-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  Use CONFIG_EXT4_FS instead of CONFIG_EXT3_FS in all of the defconfigs
  ext4: free orphan info with kvfree
  ext4: detect invalid INLINE_DATA + EXTENTS flag combination
  ext4, doc: fix and improve directory hash tree description
  ext4: wait for ongoing I/O to complete before freeing blocks
  jbd2: ensure that all ongoing I/O complete before freeing blocks
2025-10-15 07:51:57 -07:00
Zeno EndemannandTheodore Ts'o 4b471b736e ext4, doc: fix and improve directory hash tree description
Some of the details about how directory hash trees work were confusing or
outright wrong, this patch should fix those.

A note on dx_tail's dt_reserved member, as far as I can tell the kernel
never sets this explicitly, so its content is apparently left-overs from
what was there before (for the dx_root I've seen remnants of a
ext4_dir_entry_tail struct from when the dir was not yet a hash dir).

Signed-off-by: Zeno Endemann <zeno.endemann@mailbox.org>
Message-ID: <20250925152435.22749-1-zeno.endemann@mailbox.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-10-10 13:34:45 -04:00
Mallikarjun ThammanavarandJonathan Corbet 7d1c5e52ec docs: fix spelling and grammar in atomic_writes
Fix minor spelling and grammatical issues in the ext4 atomic_writes
documentation.

Signed-off-by: Mallikarjun Thammanavar <mallikarjunst09@gmail.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20250819124604.8995-1-mallikarjunst09@gmail.com
2025-08-29 16:32:17 -06:00
Bagas SanjayaandJonathan Corbet 1ce50d4e06 Documentation: ext4: Move inode table short docs into its own file
The short description of inode table is in bitmaps.rst alongside the
proper bitmpas documentation. The docs file is short enough that it fits
whole browser screen on desktop, which implies that when readers click
"Inode Table", they will essentially see bitmaps docs.

Move inode table short description.

Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Acked-by: Theodore Ts'o <tytso@mit.edu>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20250620105643.25141-7-bagasdotme@gmail.com
2025-07-02 16:57:20 -06:00
Bagas SanjayaandJonathan Corbet 36dc5367f4 Documentation: ext4: blockgroup: Add explicit title heading
Block groups documentation has three, first-level section headings.
These headings' text become toctree entries and the first one "Layout"
becomes docs title in the output, which isn't conveying the docs
contents.

Add explicit title heading and demote the rest.

Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Acked-by: Theodore Ts'o <tytso@mit.edu>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20250620105643.25141-6-bagasdotme@gmail.com
2025-07-02 16:57:20 -06:00
Bagas SanjayaandJonathan Corbet 5717d2dc3a Documentation: ext4: atomic_writes: Demote last three sections
Last three sections of atomic block writes documentation are adorned as
first-level title headings, which erroneously increase toctree entries
in overview.rst. Demote them.

Fixes: 0bf1f51e34 ("ext4: Add atomic block write documentation")
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Acked-by: Theodore Ts'o <tytso@mit.edu>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20250620105643.25141-5-bagasdotme@gmail.com
2025-07-02 16:57:20 -06:00
Bagas SanjayaandJonathan Corbet 859fac2cd6 Documentation: ext4: Reduce toctree depth
Reduce toctree depth from 6 to 2 to only show individual docs titles
on top-level toctree (index.rst) and to not spoil the entire hierarchy.

Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Acked-by: Theodore Ts'o <tytso@mit.edu>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20250620105643.25141-4-bagasdotme@gmail.com
2025-07-02 16:57:20 -06:00
Bagas SanjayaandJonathan Corbet 6e1429fb10 Documentation: ext4: Convert includes into toctrees
ext4 docs are organized in three master docs (overview.rst, globals.rst,
and dynamic.rst), in which these include other docs via include::
directive. These docs sturcture is better served by toctrees instead.

Convert the master docs to use toctrees.

Fixes: 0bf1f51e34 ("ext4: Add atomic block write documentation")
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Acked-by: Theodore Ts'o <tytso@mit.edu>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20250620105643.25141-3-bagasdotme@gmail.com
2025-07-02 16:57:20 -06:00
Ritesh Harjani (IBM)andTheodore Ts'o 0bf1f51e34 ext4: Add atomic block write documentation
Add an initial documentation around atomic writes support in ext4.

Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://patch.msgid.link/d3893b9f5ad70317abae72046e81e4c180af91bf.1747337952.git.ritesh.list@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-05-20 10:31:12 -04:00
Tom VierjahnandTheodore Ts'o ce7e8a65aa Documentation: ext4: Add fields to ext4_super_block documentation
Documentation and implementation of the ext4 super block have
slightly diverged: Padding has been removed in order to make room for
new fields that are still missing in the documentation.

Add the new fields s_encryption_level, s_first_error_errorcode,
s_last_error_errorcode to the documentation of the ext4 super block.

Fixes: f542fbe8d5 ("ext4 crypto: reserve codepoints used by the ext4 encryption feature")
Fixes: 878520ac45 ("ext4: save the error code which triggered an ext4_error() in the superblock")

Signed-off-by: Tom Vierjahn <tom.vierjahn@acm.org>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://patch.msgid.link/20250324221004.5268-1-tom.vierjahn@acm.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-04-12 21:50:41 -04:00
Bjorn HelgaasandJonathan Corbet d56b699d76 Documentation: Fix typos
Fix typos in Documentation.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20230814212822.193684-4-helgaas@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2023-08-18 11:29:03 -06:00
Zhang YiandTheodore Ts'o bd5a594b5b ext4: update doc about journal superblock description
Update the description in doc about the s_head parameter in the journal
superblock.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20230322013353.1843306-4-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-06-26 19:35:13 -04:00
Wu BoandTheodore Ts'o b7eef407e5 docs: ext4: modify the group desc size to 64
Since the default ext4 group desc size is 64 now (assuming that the
64-bit feature is enbled). And the size mentioned in this doc is 64 too.
Change it to 64.

Signed-off-by: Wu Bo <bo.wu@vivo.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20230222013525.14748-1-bo.wu@vivo.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-03-07 20:24:05 -05:00
JunChao SunandJonathan Corbet 6cf3116d5e Documentation: ext4: correct the document about superblock
The description of s_lastcheck_hi, s_first_error_time_hi, and
s_last_error_time_hi fields refer to themselves, while these means
referring to upper 8 bits (byte) of corresponding fields (s_lastcheck,
s_first_error_time, and s_last_error_time). Correct the mistake.

Signed-off-by: JunChao Sun <sunjunchao2870@gmail.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20220815125233.2040-1-sunjunchao2870@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-09-27 13:21:42 -06:00
Bagas SanjayaandTheodore Ts'o 442ec1e5bb Documentation: ext4: fix cell spacing of table heading on blockmap table
Commit 3103084afc ("ext4, doc: remove unnecessary escaping") removes
redundant underscore escaping, however the cell spacing in heading row of
blockmap table became not aligned anymore, hence triggers malformed table
warning:

Documentation/filesystems/ext4/blockmap.rst:3: WARNING: Malformed table.

+---------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| i.i_block Offset   | Where It Points                                                                                                                                                                                                              |
<snipped>...

The warning caused the table not being loaded.

Realign the heading row cell by adding missing space at the first cell
to fix the warning.

Fixes: 3103084afc ("ext4, doc: remove unnecessary escaping")
Cc: stable@kernel.org
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Wang Jianjian <wangjianjian3@huawei.com>
Cc: linux-ext4@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Link: https://lore.kernel.org/r/20220619072938.7334-1-bagasdotme@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-08-02 23:56:02 -04:00
Wang JianjianandTheodore Ts'o 3103084afc ext4, doc: remove unnecessary escaping
Signed-off-by: Wang Jianjian <wangjianjian3@huawei.com>
Link: https://lore.kernel.org/r/20220520022255.2120576-2-wangjianjian3@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-06-16 11:03:17 -04:00
wangjianjian (C)andTheodore Ts'o 7102ffe4c1 ext4, doc: fix incorrect h_reserved size
According to document and code, ext4_xattr_header's size is 32 bytes, so
h_reserved size should be 3.

Signed-off-by: Wang Jianjian <wangjianjian3@huawei.com>
Link: https://lore.kernel.org/r/92fcc3a6-7d77-8c09-4126-377fcb4c46a5@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
2022-04-12 22:24:46 -04:00
lianzhi changandTheodore Ts'o 688b0d8536 doc: fixed a typo in ext4 documentation
The unit of file system size should be TiB, not PiB

Signed-off-by: lianzhi chang <changlianzhi@uniontech.com>
Link: https://lore.kernel.org/r/20220310014415.29937-1-changlianzhi@uniontech.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-03-12 21:01:22 -05:00
Jonathan Corbet 7275423c17 ext4: docs: Take out unneeded escaping
The new file Documentation/orphan/ext4.rst escapes underscores ("\_")
throughout.  However, RST doesn't actually require that, so the escaping
only succeeds in making the document less readable.  Remove the unneeded
escapes.

Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210902220854.198850-3-corbet@lwn.net
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-10-07 08:46:02 -06:00
Jonathan Corbet 91c76340b4 ext4: docs: switch away from list-table
Commit 3a6541e97c (Add documentation about the orphan file feature) added
a new document on orphan files, which is great.  But the use of
"list-table" results in documents that are absolutely unreadable in their
plain-text form.  Switch this file to the regular RST table format instead;
the rendered (HTML) output is identical.

Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210902220854.198850-2-corbet@lwn.net
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-10-07 08:46:02 -06:00
Jan KaraandTheodore Ts'o 3a6541e97c ext4: Orphan file documentation
Add documentation about the orphan file feature.

Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210816095713.16537-4-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-08-30 23:36:51 -04:00
Linus Torvalds a6ecc2a491 Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 updates from Ted Ts'o:
 "In addition to bug fixes and cleanups, there are two new features for
  ext4 in 5.14:

   - Allow applications to poll on changes to
     /sys/fs/ext4/*/errors_count

   - Add the ioctl EXT4_IOC_CHECKPOINT which allows the journal to be
     checkpointed, truncated and discarded or zero'ed"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (32 commits)
  jbd2: export jbd2_journal_[un]register_shrinker()
  ext4: notify sysfs on errors_count value change
  fs: remove bdev_try_to_free_page callback
  ext4: remove bdev_try_to_free_page() callback
  jbd2: simplify journal_clean_one_cp_list()
  jbd2,ext4: add a shrinker to release checkpointed buffers
  jbd2: remove redundant buffer io error checks
  jbd2: don't abort the journal when freeing buffers
  jbd2: ensure abort the journal if detect IO error when writing original buffer back
  jbd2: remove the out label in __jbd2_journal_remove_checkpoint()
  ext4: no need to verify new add extent block
  jbd2: clean up misleading comments for jbd2_fc_release_bufs
  ext4: add check to prevent attempting to resize an fs with sparse_super2
  ext4: consolidate checks for resize of bigalloc into ext4_resize_begin
  ext4: remove duplicate definition of ext4_xattr_ibody_inline_set()
  ext4: fsmap: fix the block/inode bitmap comment
  ext4: fix comment for s_hash_unsigned
  ext4: use local variable ei instead of EXT4_I() macro
  ext4: fix avefreec in find_group_orlov
  ext4: correct the cache_nr in tracepoint ext4_es_shrink_exit
  ...
2021-06-30 19:37:39 -07:00
Leah RumancikandTheodore Ts'o fd7b23be92 ext4: update journal documentation
Add a section about journal checkpointing, including information about
the ioctl EXT4_IOC_CHECKPOINT which can be used to trigger a journal
checkpoint from userspace.

Also, update the journal allocation information to reflect that up to
10240000 blocks are used for the journal and that the journal is not
necessarily contiguous.

Signed-off-by: Leah Rumancik <leah.rumancik@gmail.com>

Changes in v5:
- clarify behavior of DRY_RUN flag
Link: https://lore.kernel.org/r/20210518151327.130198-3-leah.rumancik@gmail.com

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-06-22 21:34:17 -04:00
Mauro Carvalho ChehabandJonathan Corbet d9d2c82738 docs: filesystems: ext4: blockgroup.rst: replace some characters
The conversion tools used during DocBook/LaTeX/html/Markdown->ReST
conversion and some cut-and-pasted text contain some characters that
aren't easily reachable on standard keyboards and/or could cause
troubles when parsed by the documentation build system.

Replace the occurences of the following characters:

	- U+2217 ('∗'): ASTERISK OPERATOR
	  use ASCII asterisk instead of the ASTERISK OPERATOR

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Acked-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/c5c3c384c48779ca7c9dcd90183cefe20ac82928.1623826294.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-06-17 13:22:33 -06:00