David Disseldorp 7c1f14f6e8 docs: initramfs: file data alignment via name padding ...

The existing cpio extraction logic reads (maximum PATH_MAX) name_len
bytes from the archive into the collected name buffer and ensures that
the trailing byte is a null-terminator. This allows the actual file name
to be shorter than name_len, with the name string simply zero-terminated
prior to the last byte.

Initramfs generators, such as dracut-cpio[1], can take advantage of name
zero-padding to align file data segments within the archive to
filesystem block boundaries. Block boundary alignment may allow the
copy_file_range syscall to reflink archive source and destination
extents.

Link: 300e4b116c [1]
Signed-off-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Nicolas Schier <nsc@kernel.org>
Link: https://lore.kernel.org/r/20250819032607.28727-7-ddiss@suse.de
Signed-off-by: Nathan Chancellor <nathan@kernel.org>

2025-08-20 16:02:56 -07:00

..

buffer-format.rst

docs: initramfs: file data alignment via name padding

2025-08-20 16:02:56 -07:00

early_userspace_support.rst

Documentation: Fix intiramfs script name

2021-07-18 23:48:14 +09:00

index.rst

docs: add SPDX tags to new index files

2019-07-15 11:03:03 -03:00