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Diffstat (limited to 'Documentation/filesystems/ext4/directory.rst')
| -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: |