The bound check condition should always be met because we selected `set_basic` as our encoding type. But that code is very far away, so assert it is true so if it is ever false we can catch it, and add a bounds check. Port of facebook/zstd@1047097dad Reported-by: Coverity (CID 1524446) Reviewed-by: Damian Szuberski <szuberskidamian@gmail.com> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de> Ported-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Closes #14212 |
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include | ||
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README.md | ||
zfs_zstd.c | ||
zstd_sparc.c | ||
zstd-in.c |
ZSTD-On-ZFS Library Manual
Introduction
This subtree contains the ZSTD library used in ZFS. It is heavily cut-down by dropping any unneeded files, and combined into a single file, but otherwise is intentionally unmodified. Please do not alter the file containing the zstd library, besides upgrading to a newer ZSTD release.
Tree structure:
zfs_zstd.c
are the actualzfs
kernel module hooks.lib/
contains the unmodified version of theZstandard
libraryzstd-in.c
is our template file for generating the single-file libraryinclude/
: This directory contains supplemental includes for platform compatibility, which are not expected to be used by ZFS elsewhere in the future. Thus we keep them private to ZSTD.
Updating ZSTD
To update ZSTD the following steps need to be taken:
- Grab the latest release of ZSTD.
- Copy the files output by the following script to
module/zstd/lib/
:grep include [path to zstd]/contrib/single_file_libs/zstd-in.c | awk '{ print $2 }'
- Remove debug.c, threading.c, and zstdmt_compress.c.
- Update Makefiles with resulting file lists.
- Follow symbol renaming notes in
include/zstd_compat_wrapper.h
Altering ZSTD and breaking changes
If ZSTD made changes that break compatibility or you need to make breaking changes to the way we handle ZSTD, it is required to maintain backwards compatibility.
We already save the ZSTD version number within the block header to be used to add future compatibility checks and/or fixes. However, currently it is not actually used in such a way.