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author | 2021-04-30 15:35:30 -0700 | |
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committer | 2021-04-30 15:35:30 -0700 | |
commit | 9f67672a817ec046f7554a885f0fe0d60e1bf99f (patch) | |
tree | 9d238a2cbfabc479bdb31c5879b8f24415dc3aa2 /Documentation/filesystems | |
parent | Merge tag 'dlm-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/teiglan... (diff) | |
parent | ext4: wipe ext4_dir_entry2 upon file deletion (diff) | |
download | linux-9f67672a817ec046f7554a885f0fe0d60e1bf99f.tar.gz linux-9f67672a817ec046f7554a885f0fe0d60e1bf99f.tar.bz2 linux-9f67672a817ec046f7554a885f0fe0d60e1bf99f.zip |
Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 updates from Ted Ts'o:
"New features for ext4 this cycle include support for encrypted
casefold, ensure that deleted file names are cleared in directory
blocks by zeroing directory entries when they are unlinked or moved as
part of a hash tree node split. We also improve the block allocator's
performance on a freshly mounted file system by prefetching block
bitmaps.
There are also the usual cleanups and bug fixes, including fixing a
page cache invalidation race when there is mixed buffered and direct
I/O and the block size is less than page size, and allow the dax flag
to be set and cleared on inline directories"
* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (32 commits)
ext4: wipe ext4_dir_entry2 upon file deletion
ext4: Fix occasional generic/418 failure
fs: fix reporting supported extra file attributes for statx()
ext4: allow the dax flag to be set and cleared on inline directories
ext4: fix debug format string warning
ext4: fix trailing whitespace
ext4: fix various seppling typos
ext4: fix error return code in ext4_fc_perform_commit()
ext4: annotate data race in jbd2_journal_dirty_metadata()
ext4: annotate data race in start_this_handle()
ext4: fix ext4_error_err save negative errno into superblock
ext4: fix error code in ext4_commit_super
ext4: always panic when errors=panic is specified
ext4: delete redundant uptodate check for buffer
ext4: do not set SB_ACTIVE in ext4_orphan_cleanup()
ext4: make prefetch_block_bitmaps default
ext4: add proc files to monitor new structures
ext4: improve cr 0 / cr 1 group scanning
ext4: add MB_NUM_ORDERS macro
ext4: add mballoc stats proc file
...
Diffstat (limited to 'Documentation/filesystems')
-rw-r--r-- | Documentation/filesystems/ext4/directory.rst | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/Documentation/filesystems/ext4/directory.rst b/Documentation/filesystems/ext4/directory.rst index 073940cc64ed..55f618b37144 100644 --- a/Documentation/filesystems/ext4/directory.rst +++ b/Documentation/filesystems/ext4/directory.rst @@ -121,6 +121,31 @@ The directory file type is one of the following values: * - 0x7 - Symbolic link. +To support directories that are both encrypted and casefolded directories, we +must also include hash information in the directory entry. We append +``ext4_extended_dir_entry_2`` to ``ext4_dir_entry_2`` except for the entries +for dot and dotdot, which are kept the same. The structure follows immediately +after ``name`` and is included in the size listed by ``rec_len`` If a directory +entry uses this extension, it may be up to 271 bytes. + +.. list-table:: + :widths: 8 8 24 40 + :header-rows: 1 + + * - Offset + - Size + - Name + - Description + * - 0x0 + - \_\_le32 + - hash + - The hash of the directory name + * - 0x4 + - \_\_le32 + - minor\_hash + - The minor hash of the directory name + + In order to add checksums to these classic directory blocks, a phony ``struct ext4_dir_entry`` is placed at the end of each leaf block to hold the checksum. The directory entry is 12 bytes long. The inode @@ -322,6 +347,8 @@ The directory hash is one of the following values: - Half MD4, unsigned. * - 0x5 - Tea, unsigned. + * - 0x6 + - Siphash. Interior nodes of an htree are recorded as ``struct dx_node``, which is also the full length of a data block: |