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author | Linus Torvalds <torvalds@linux-foundation.org> | 2021-11-01 21:39:22 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-11-01 21:39:22 +0300 |
commit | 67a135b80eb75b62d92a809b0246e70524f69b89 (patch) | |
tree | f199430bc1ffd12d70e2a884724b51d09777d71e /lib/decompress_unxz.c | |
parent | cd3e8ea847eea97095aa01de3d12674d35fd0199 (diff) | |
parent | a0961f351d82d43ab0b845304caa235dfe249ae9 (diff) | |
download | linux-67a135b80eb75b62d92a809b0246e70524f69b89.tar.xz |
Merge tag 'erofs-for-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs
Pull erofs updates from Gao Xiang:
"There are some new features available for this cycle. Firstly, EROFS
LZMA algorithm support, specifically called MicroLZMA, is available as
an option for embedded devices, LiveCDs and/or as the secondary
auxiliary compression algorithm besides the primary algorithm in one
file.
In order to better support the LZMA fixed-sized output compression,
especially for 4KiB pcluster size (which has lowest memory pressure
thus useful for memory-sensitive scenarios), Lasse introduced a new
LZMA header/container format called MicroLZMA to minimize the original
LZMA1 header (for example, we don't need to waste 4-byte dictionary
size and another 8-byte uncompressed size, which can be calculated by
fs directly, for each pcluster) and enable EROFS fixed-sized output
compression.
Note that MicroLZMA can also be later used by other things in addition
to EROFS too where wasting minimal amount of space for headers is
important and it can be only compiled by enabling XZ_DEC_MICROLZMA.
MicroLZMA has been supported by the latest upstream XZ embedded [1] &
XZ utils [2], apply the latest related XZ embedded upstream patches by
the XZ author Lasse here.
Secondly, multiple device is also supported in this cycle, which is
designed for multi-layer container images. By working together with
inter-layer data deduplication and compression, we can achieve the
next high-performance container image solution. Our team will announce
the new Nydus container image service [3] implementation with new RAFS
v6 (EROFS-compatible) format in Open Source Summit 2021 China [4]
soon.
Besides, the secondary compression head support and readmore
decompression strategy are also included in this cycle. There are also
some minor bugfixes and cleanups, as always.
Summary:
- support multiple devices for multi-layer container images;
- support the secondary compression head;
- support readmore decompression strategy;
- support new LZMA algorithm (specifically called MicroLZMA);
- some bugfixes & cleanups"
* tag 'erofs-for-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs:
erofs: don't trigger WARN() when decompression fails
erofs: get rid of ->lru usage
erofs: lzma compression support
erofs: rename some generic methods in decompressor
lib/xz, lib/decompress_unxz.c: Fix spelling in comments
lib/xz: Add MicroLZMA decoder
lib/xz: Move s->lzma.len = 0 initialization to lzma_reset()
lib/xz: Validate the value before assigning it to an enum variable
lib/xz: Avoid overlapping memcpy() with invalid input with in-place decompression
erofs: introduce readmore decompression strategy
erofs: introduce the secondary compression head
erofs: get compression algorithms directly on mapping
erofs: add multiple device support
erofs: decouple basic mount options from fs_context
erofs: remove the fast path of per-CPU buffer decompression
Diffstat (limited to 'lib/decompress_unxz.c')
-rw-r--r-- | lib/decompress_unxz.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/lib/decompress_unxz.c b/lib/decompress_unxz.c index a2f38e23004a..9f4262ee33a5 100644 --- a/lib/decompress_unxz.c +++ b/lib/decompress_unxz.c @@ -20,8 +20,8 @@ * * The worst case for in-place decompression is that the beginning of * the file is compressed extremely well, and the rest of the file is - * uncompressible. Thus, we must look for worst-case expansion when the - * compressor is encoding uncompressible data. + * incompressible. Thus, we must look for worst-case expansion when the + * compressor is encoding incompressible data. * * The structure of the .xz file in case of a compressed kernel is as follows. * Sizes (as bytes) of the fields are in parenthesis. @@ -58,7 +58,7 @@ * uncompressed size of the payload is in practice never less than the * payload size itself. The LZMA2 format would allow uncompressed size * to be less than the payload size, but no sane compressor creates such - * files. LZMA2 supports storing uncompressible data in uncompressed form, + * files. LZMA2 supports storing incompressible data in uncompressed form, * so there's never a need to create payloads whose uncompressed size is * smaller than the compressed size. * @@ -167,8 +167,8 @@ * memeq and memzero are not used much and any remotely sane implementation * is fast enough. memcpy/memmove speed matters in multi-call mode, but * the kernel image is decompressed in single-call mode, in which only - * memcpy speed can matter and only if there is a lot of uncompressible data - * (LZMA2 stores uncompressible chunks in uncompressed form). Thus, the + * memmove speed can matter and only if there is a lot of incompressible data + * (LZMA2 stores incompressible chunks in uncompressed form). Thus, the * functions below should just be kept small; it's probably not worth * optimizing for speed. */ |