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path: root/fs/squashfs/decompressor.c
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2017-09-09squashfs: Add zstd supportSean Purcell1-0/+7
Add zstd compression and decompression support to SquashFS. zstd is a great fit for SquashFS because it can compress at ratios approaching xz, while decompressing twice as fast as zlib. For SquashFS in particular, it can decompress as fast as lzo and lz4. It also has the flexibility to turn down the compression ratio for faster compression times. The compression benchmark is run on the file tree from the SquashFS archive found in ubuntu-16.10-desktop-amd64.iso [1]. It uses `mksquashfs` with the default block size (128 KB) and and various compression algorithms/levels. xz and zstd are also benchmarked with 256 KB blocks. The decompression benchmark times how long it takes to `tar` the file tree into `/dev/null`. See the benchmark file in the upstream zstd source repository located under `contrib/linux-kernel/squashfs-benchmark.sh` [2] for details. I ran the benchmarks on a Ubuntu 14.04 VM with 2 cores and 4 GiB of RAM. The VM is running on a MacBook Pro with a 3.1 GHz Intel Core i7 processor, 16 GB of RAM, and a SSD. | Method | Ratio | Compression MB/s | Decompression MB/s | |----------------|-------|------------------|--------------------| | gzip | 2.92 | 15 | 128 | | lzo | 2.64 | 9.5 | 217 | | lz4 | 2.12 | 94 | 218 | | xz | 3.43 | 5.5 | 35 | | xz 256 KB | 3.53 | 5.4 | 40 | | zstd 1 | 2.71 | 96 | 210 | | zstd 5 | 2.93 | 69 | 198 | | zstd 10 | 3.01 | 41 | 225 | | zstd 15 | 3.13 | 11.4 | 224 | | zstd 16 256 KB | 3.24 | 8.1 | 210 | This patch was written by Sean Purcell <me@seanp.xyz>, but I will be taking over the submission process. [1] http://releases.ubuntu.com/16.10/ [2] https://github.com/facebook/zstd/blob/dev/contrib/linux-kernel/squashfs-benchmark.sh zstd source repository: https://github.com/facebook/zstd Signed-off-by: Sean Purcell <me@seanp.xyz> Signed-off-by: Nick Terrell <terrelln@fb.com> Signed-off-by: Chris Mason <clm@fb.com> Acked-by: Phillip Lougher <phillip@squashfs.org.uk>
2016-04-04mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macrosKirill A. Shutemov1-1/+1
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-11-27Squashfs: Add LZ4 compression configuration optionPhillip Lougher1-0/+7
Add the glue code, and also update the documentation. Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
2013-11-20Squashfs: Generalise paging handling in the decompressorsPhillip Lougher1-3/+11
Further generalise the decompressors by adding a page handler abstraction. This adds helpers to allow the decompressors to access and process the output buffers in an implementation independant manner. This allows different types of output buffer to be passed to the decompressors, with the implementation specific aspects handled at decompression time, but without the knowledge being held in the decompressor wrapper code. This will allow the decompressors to handle Squashfs cache buffers, and page cache pages. This patch adds the abstraction and an implementation for the caches. Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk> Reviewed-by: Minchan Kim <minchan@kernel.org>
2013-11-20Squashfs: Refactor decompressor interface and codePhillip Lougher1-15/+32
The decompressor interface and code was written from the point of view of single-threaded operation. In doing so it mixed a lot of single-threaded implementation specific aspects into the decompressor code and elsewhere which makes it difficult to seamlessly support multiple different decompressor implementations. This patch does the following: 1. It removes compressor_options parsing from the decompressor init() function. This allows the decompressor init() function to be dynamically called to instantiate multiple decompressors, without the compressor options needing to be read and parsed each time. 2. It moves threading and all sleeping operations out of the decompressors. In doing so, it makes the decompressors non-blocking wrappers which only deal with interfacing with the decompressor implementation. 3. It splits decompressor.[ch] into decompressor generic functions in decompressor.[ch], and moves the single threaded decompressor implementation into decompressor_single.c. The result of this patch is Squashfs should now be able to support multiple decompressors by adding new decompressor_xxx.c files with specialised implementations of the functions in decompressor_single.c Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk> Reviewed-by: Minchan Kim <minchan@kernel.org>
2011-07-22Squashfs: Make ZLIB compression support optionalPhillip Lougher1-0/+6
Squashfs now supports XZ and LZO compression in addition to ZLIB. As such it no longer makes sense to always include ZLIB support. In particular embedded systems may only use LZO or XZ compression, and the ability to exclude ZLIB support will reduce kernel size. Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
2011-05-26Squashfs: update email addressPhillip Lougher1-1/+1
My existing email address may stop working in a month or two, so update email to one that will continue working. Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2011-02-28Squashfs: extend decompressor framework to handle compression optionsPhillip Lougher1-0/+34
Extend decompressor framework to handle compression options stored in the filesystem. These options can be used by the relevant decompressor at initialisation time to over-ride defaults. The presence of compression options in the filesystem is indicated by the COMP_OPT filesystem flag. If present the data is read from the filesystem and passed to the decompressor init function. The decompressor init function signature has been extended to take this data. Also update the init function signature in the glib, lzo and xz decompressor wrappers. Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2011-01-14Squashfs: simplify CONFIG_SQUASHFS_LZO handlingPhillip Lougher1-6/+2
Get rid of messy repeated #if(n)def CONFIG_SQUASHFS_LZO code in decompressor.c Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2011-01-14Squashfs: move squashfs_i() definition from squashfs.hPhillip Lougher1-1/+0
Move squashfs_i() definition out of squashfs.h, this eliminates the need to #include squashfs_fs_i.h from numerous files. Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2011-01-14Squashfs: Add XZ compression configuration optionPhillip Lougher1-0/+7
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2010-08-05Squashfs: Add LZO compression supportChan Jeong1-0/+6
Signed-off-by: Chan Jeong <chan.jeong@lge.com> Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2010-01-21Squashfs: add decompressor entries for lzma and lzoPhillip Lougher1-0/+10
Add knowledge of lzma/lzo compression formats to the decompressor framework. For now these are added as unsupported. Without these entries lzma/lzo compressed filesystems will be flagged as having unknown compression which is undesirable. Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2010-01-21Squashfs: add a decompressor frameworkPhillip Lougher1-0/+58
This adds a decompressor framework which allows multiple compression algorithms to be cleanly supported. Also update zlib wrapper and other code to use the new framework. Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
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