freebsd-dev/sys/geom/uzip/g_uzip_cloop.h
Conrad Meyer eefd8f96fb geom_uzip(4), mkuzip(8): Add Zstd image mode
The Zstd format bumps the CLOOP major number to 4 to avoid incompatibility
with older systems.  Support in geom_uzip(4) is conditional on the ZSTDIO
kernel option, which is enabled in amd64 GENERIC, but not all in-tree
configurations.

mkuzip(8) was modified slightly to always initialize the nblocks + 1'th
offset in the CLOOP file format.  Previously, it was only initialized in the
case where the final compressed block happened to be unaligned w.r.t.
DEV_BSIZE.  The "Fake" last+1 block change in r298619 means that the final
compressed block's 'blen' was never correct unless the compressed uzip image
happened to be BSIZE-aligned.  This happened in about 1 out of every 512
cases.  The zlib and lzma decompressors are probably tolerant of extra trash
following the frame they were told to decode, but Zstd complains that the
input size is incorrect.

Correspondingly, geom_uzip(4) was modified slightly to avoid trashing the
nblocks + 1'th offset when it is known to be initialized to a good value.
This corrects the calculated final real cluster compressed length to match
that printed by mkuzip(8).

mkuzip(8) was refactored somewhat to reduce code duplication and increase
ease of adding other compression formats.

  * Input block size validation was pulled out of individual compression
    init routines into main().

  * Init routines now validate a user-provided compression level or select
    an algorithm-specific default, if none was provided.

  * A new interface for calculating the maximal compressed size of an
    incompressible input block was added for each driver.  The generic code
    uses it to validate against MAXPHYS as well as to allocate compression
    result buffers in the generic code.

  * Algorithm selection is now driven by a table lookup, to increase ease of
    adding other formats in the future.

mkuzip(8) gained the ability to explicitly specify a compression level with
'-C'.  The prior defaults -- 9 for zlib and 6 for lzma -- are maintained.
The new zstd default is 9, to match zlib.

Rather than select lzma or zlib with '-L' or its absense, respectively, a
new argument '-A <algorithm>' is provided to select 'zlib', 'lzma', or
'zstd'.  '-L' is considered deprecated, but will probably never be removed.

All of the new features were documented in mkuzip.8; the page was also
cleaned up slightly.

Relnotes:	yes
2019-08-13 23:32:56 +00:00

62 lines
2.3 KiB
C

/*
* Copyright (c) 2004-2016 Maxim Sobolev <sobomax@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
/* CLOOP format and related constants */
/*
* Integer values (block size, number of blocks, offsets)
* are stored in big-endian (network) order on disk.
*/
#define CLOOP_MAGIC_LEN 128
#define CLOOP_OFS_COMPR 0x0b
#define CLOOP_OFS_VERSN (CLOOP_OFS_COMPR + 1)
#define CLOOP_MAJVER_2 '2'
#define CLOOP_MAJVER_3 '3'
#define CLOOP_MAJVER_4 '4'
#define CLOOP_COMP_LIBZ 'V'
#define CLOOP_COMP_LIBZ_DDP 'v'
#define CLOOP_COMP_LZMA 'L'
#define CLOOP_COMP_LZMA_DDP 'l'
#define CLOOP_COMP_ZSTD 'Z'
#define CLOOP_COMP_ZSTD_DDP 'z'
#define CLOOP_MINVER_LZMA CLOOP_MAJVER_3
#define CLOOP_MINVER_ZLIB CLOOP_MAJVER_2
#define CLOOP_MINVER_ZSTD CLOOP_MAJVER_4
#define CLOOP_MINVER_RELIABLE_LASTBLKSZ CLOOP_MAJVER_4
struct cloop_header {
char magic[CLOOP_MAGIC_LEN]; /* cloop magic */
uint32_t blksz; /* block size */
uint32_t nblocks; /* number of blocks */
};