From: gaoxiang25@huawei.com (Gao Xiang) Subject: [PATCH v6 21/24] erofs: introduce LZ4 decompression inplace Date: Fri, 2 Aug 2019 20:53:44 +0800 Message-ID: <20190802125347.166018-22-gaoxiang25@huawei.com> (raw) In-Reply-To: <20190802125347.166018-1-gaoxiang25@huawei.com> compressed data will be usually loaded into last pages of the extent (the last page for 4k) for in-place decompression (more specifically, in-place IO), as ilustration below, start of compressed logical extent | end of this logical extent | | ______v___________________________v________ ... | page 6 | page 7 | page 8 | page 9 | ... |__________|__________|__________|__________| . ^ . ^ . |compressed| . | data | . . . |< dstsize >|<margin>| oend iend op ip Therefore, it's possible to do decompression inplace (thus no memcpy at all) if the margin is sufficient and safe enough [1], and it can be implemented only for fixed-size output compression compared with fixed-size input compression. No memcpy for most of in-place IO (about 99% of enwik9) after decompression inplace is implemented and sequential read will be improved of course (see the following patches for test results). [1] https://github.com/lz4/lz4/commit/b17f578a919b7e6b078cede2d52be29dd48c8e8c https://github.com/lz4/lz4/commit/5997e139f53169fa3a1c1b4418d2452a90b01602 Signed-off-by: Gao Xiang <gaoxiang25 at huawei.com> --- fs/erofs/decompressor.c | 36 ++++++++++++++++++++++++++++++++---- fs/erofs/erofs_fs.h | 2 +- 2 files changed, 33 insertions(+), 5 deletions(-) diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c index 244afb29907d..1e9e1359e40c 100644 --- a/fs/erofs/decompressor.c +++ b/fs/erofs/decompressor.c @@ -15,6 +15,9 @@ #endif #define LZ4_MAX_DISTANCE_PAGES (DIV_ROUND_UP(LZ4_DISTANCE_MAX, PAGE_SIZE) + 1) +#ifndef LZ4_DECOMPRESS_INPLACE_MARGIN +#define LZ4_DECOMPRESS_INPLACE_MARGIN(srcsize) (((srcsize) >> 8) + 32) +#endif struct z_erofs_decompressor { /* @@ -117,7 +120,7 @@ static int lz4_decompress(struct z_erofs_decompress_req *rq, u8 *out) { unsigned int inputmargin, inlen; u8 *src; - bool copied; + bool copied, support_0padding; int ret; if (rq->inputsize > PAGE_SIZE) @@ -125,13 +128,38 @@ static int lz4_decompress(struct z_erofs_decompress_req *rq, u8 *out) src = kmap_atomic(*rq->in); inputmargin = 0; + support_0padding = false; + + /* decompression inplace is only safe when 0padding is enabled */ + if (EROFS_SB(rq->sb)->requirements & EROFS_REQUIREMENT_LZ4_0PADDING) { + support_0padding = true; + + while (!src[inputmargin & ~PAGE_MASK]) + if (!(++inputmargin & ~PAGE_MASK)) + break; + + if (inputmargin >= rq->inputsize) { + kunmap_atomic(src); + return -EIO; + } + } copied = false; inlen = rq->inputsize - inputmargin; if (rq->inplace_io) { - src = generic_copy_inplace_data(rq, src, inputmargin); - inputmargin = 0; - copied = true; + const uint oend = (rq->pageofs_out + + rq->outputsize) & ~PAGE_MASK; + const uint nr = PAGE_ALIGN(rq->pageofs_out + + rq->outputsize) >> PAGE_SHIFT; + + if (rq->partial_decoding || !support_0padding || + rq->out[nr - 1] != rq->in[0] || + rq->inputsize - oend < + LZ4_DECOMPRESS_INPLACE_MARGIN(inlen)) { + src = generic_copy_inplace_data(rq, src, inputmargin); + inputmargin = 0; + copied = true; + } } ret = LZ4_decompress_safe_partial(src + inputmargin, out, diff --git a/fs/erofs/erofs_fs.h b/fs/erofs/erofs_fs.h index b307060dd220..25bda459f2e6 100644 --- a/fs/erofs/erofs_fs.h +++ b/fs/erofs/erofs_fs.h @@ -17,7 +17,7 @@ * incompatible with this kernel version. */ #define EROFS_REQUIREMENT_LZ4_0PADDING 0x00000001 -#define EROFS_ALL_REQUIREMENTS 0 +#define EROFS_ALL_REQUIREMENTS EROFS_REQUIREMENT_LZ4_0PADDING struct erofs_super_block { /* 0 */__le32 magic; /* in the little endian */ -- 2.17.1
next prev parent reply index Thread overview: 141+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-08-02 12:53 [PATCH v6 00/24] erofs: promote erofs from staging Gao Xiang 2019-08-02 12:53 ` [PATCH v6 01/24] erofs: add on-disk layout Gao Xiang [not found] ` <20190829095954.GB20598@infradead.org> 2019-09-01 7:54 ` Gao Xiang 2019-09-02 12:45 ` Christoph Hellwig 2019-09-02 13:02 ` Gao Xiang 2019-09-02 8:40 ` Pavel Machek 2019-09-02 10:35 ` Gao Xiang [not found] ` <20190829103252.GA64893@architecture4> [not found] ` <67d6efbbc9ac6db23215660cb970b7ef29dc0c1d.camel@perches.com> [not found] ` <20190830120714.GN2752@twin.jikos.cz> 2019-09-02 8:43 ` Pavel Machek 2019-09-02 14:07 ` David Sterba 2019-09-03 11:27 ` Pavel Machek 2019-08-02 12:53 ` [PATCH v6 02/24] erofs: add erofs in-memory stuffs Gao Xiang 2019-08-02 12:53 ` [PATCH v6 03/24] erofs: add super block operations Gao Xiang [not found] ` <20190829101545.GC20598@infradead.org> [not found] ` <20190829105048.GB64893@architecture4> 2019-08-30 16:39 ` Christoph Hellwig 2019-08-30 17:15 ` Gao Xiang 2019-08-31 0:54 ` Gao Xiang 2019-08-31 6:34 ` Amir Goldstein 2019-08-31 6:48 ` Gao Xiang 2019-09-01 8:54 ` Gao Xiang 2019-09-02 12:51 ` Christoph Hellwig 2019-09-02 14:43 ` Gao Xiang 2019-09-02 15:19 ` Christoph Hellwig 2019-09-02 15:24 ` Gao Xiang 2019-08-02 12:53 ` [PATCH v6 04/24] erofs: add raw address_space operations Gao Xiang [not found] ` <20190829101721.GD20598@infradead.org> [not found] ` <20190829114610.GF64893@architecture4> 2019-08-30 16:40 ` Christoph Hellwig 2019-08-30 17:23 ` Gao Xiang 2019-08-02 12:53 ` [PATCH v6 05/24] erofs: add inode operations Gao Xiang [not found] ` <20190829102426.GE20598@infradead.org> [not found] ` <20190829115922.GG64893@architecture4> 2019-08-30 16:42 ` Christoph Hellwig 2019-08-30 18:46 ` Gao Xiang 2019-09-01 9:34 ` Gao Xiang 2019-09-02 12:53 ` Christoph Hellwig 2019-09-02 13:43 ` David Sterba 2019-09-02 13:55 ` Gao Xiang 2019-08-02 12:53 ` [PATCH v6 06/24] erofs: support special inode Gao Xiang [not found] ` <20190829102503.GF20598@infradead.org> 2019-09-01 9:39 ` Gao Xiang 2019-08-02 12:53 ` [PATCH v6 07/24] erofs: add directory operations Gao Xiang 2019-08-02 12:53 ` [PATCH v6 08/24] erofs: add namei functions Gao Xiang 2019-08-02 12:53 ` [PATCH v6 09/24] erofs: support tracepoint Gao Xiang 2019-08-02 12:53 ` [PATCH v6 10/24] erofs: update Kconfig and Makefile Gao Xiang 2019-08-02 12:53 ` [PATCH v6 11/24] erofs: introduce xattr & posixacl support Gao Xiang 2019-08-02 12:53 ` [PATCH v6 12/24] erofs: introduce tagged pointer Gao Xiang 2019-08-02 12:53 ` [PATCH v6 13/24] erofs: add compression indexes support Gao Xiang 2019-08-02 12:53 ` [PATCH v6 14/24] erofs: introduce superblock registration Gao Xiang 2019-08-02 12:53 ` [PATCH v6 15/24] erofs: introduce erofs shrinker Gao Xiang 2019-08-02 12:53 ` [PATCH v6 16/24] erofs: introduce workstation for decompression Gao Xiang 2019-08-02 12:53 ` [PATCH v6 17/24] erofs: introduce per-CPU buffers implementation Gao Xiang 2019-08-02 12:53 ` [PATCH v6 18/24] erofs: introduce pagevec for decompression subsystem Gao Xiang 2019-08-02 12:53 ` [PATCH v6 19/24] erofs: add erofs_allocpage() Gao Xiang 2019-08-02 12:53 ` [PATCH v6 20/24] erofs: introduce generic decompression backend Gao Xiang 2019-08-02 12:53 ` Gao Xiang [this message] 2019-08-02 12:53 ` [PATCH v6 22/24] erofs: introduce the decompression frontend Gao Xiang 2019-08-02 12:53 ` [PATCH v6 23/24] erofs: introduce cached decompression Gao Xiang 2019-08-02 12:53 ` [PATCH v6 24/24] erofs: add document Gao Xiang 2019-09-01 5:51 ` [PATCH 00/21] erofs: patchset addressing Christoph's comments Gao Xiang 2019-09-01 5:51 ` [PATCH 01/21] erofs: remove all the byte offset comments Gao Xiang 2019-09-02 12:05 ` Christoph Hellwig 2019-09-01 5:51 ` [PATCH 02/21] erofs: on-disk format should have explicitly assigned numbers Gao Xiang 2019-09-02 12:05 ` Christoph Hellwig 2019-09-01 5:51 ` [PATCH 03/21] erofs: some macros are much more readable as a function Gao Xiang 2019-09-02 12:06 ` Christoph Hellwig 2019-09-01 5:51 ` [PATCH 04/21] erofs: kill __packed for on-disk structures Gao Xiang 2019-09-02 12:06 ` Christoph Hellwig 2019-09-01 5:51 ` [PATCH 05/21] erofs: update erofs_inode_is_data_compressed helper Gao Xiang 2019-09-02 12:07 ` Christoph Hellwig 2019-09-01 5:51 ` [PATCH 06/21] erofs: kill erofs_{init,exit}_inode_cache Gao Xiang 2019-09-02 12:09 ` Christoph Hellwig 2019-09-01 5:51 ` [PATCH 07/21] erofs: use erofs_inode naming Gao Xiang 2019-09-02 12:10 ` Christoph Hellwig 2019-09-02 12:13 ` Gao Xiang 2019-09-02 12:47 ` Christoph Hellwig 2019-09-02 13:33 ` Gao Xiang 2019-09-01 5:51 ` [PATCH 08/21] erofs: update comments in inode.c Gao Xiang 2019-09-01 5:51 ` [PATCH 09/21] erofs: update erofs symlink stuffs Gao Xiang 2019-09-02 12:11 ` Christoph Hellwig 2019-09-01 5:51 ` [PATCH 10/21] erofs: kill is_inode_layout_compression() Gao Xiang 2019-09-02 12:11 ` Christoph Hellwig 2019-09-01 5:51 ` [PATCH 11/21] erofs: use dsb instead of layout for ondisk super_block Gao Xiang 2019-09-02 12:12 ` Christoph Hellwig 2019-09-02 12:15 ` Gao Xiang 2019-09-01 5:51 ` [PATCH 12/21] erofs: kill verbose debug info in erofs_fill_super Gao Xiang 2019-09-02 12:14 ` Christoph Hellwig 2019-09-02 12:18 ` Gao Xiang 2019-09-01 5:51 ` [PATCH 13/21] erofs: simplify erofs_grab_bio() since bio_alloc() never fail Gao Xiang 2019-09-02 12:20 ` Christoph Hellwig 2019-09-01 5:51 ` [PATCH 14/21] erofs: kill prio and nofail of erofs_get_meta_page() Gao Xiang 2019-09-02 12:21 ` Christoph Hellwig 2019-09-01 5:51 ` [PATCH 15/21] erofs: kill __submit_bio() Gao Xiang 2019-09-01 5:51 ` [PATCH 16/21] erofs: kill magic underscores Gao Xiang 2019-09-02 12:26 ` Christoph Hellwig 2019-09-02 12:39 ` Gao Xiang 2019-09-02 12:54 ` Christoph Hellwig 2019-09-02 13:38 ` Gao Xiang 2019-09-01 5:51 ` [PATCH 17/21] erofs: use a switch statement when dealing with the file modes Gao Xiang 2019-09-02 12:27 ` Christoph Hellwig 2019-09-01 5:51 ` [PATCH 18/21] erofs: add "erofs_" prefix for common and short functions Gao Xiang 2019-09-02 12:28 ` Christoph Hellwig 2019-09-01 5:51 ` [PATCH 19/21] erofs: kill all erofs specific fault injection Gao Xiang 2019-09-02 12:28 ` Christoph Hellwig 2019-09-01 5:51 ` [PATCH 20/21] erofs: kill use_vmap module parameter Gao Xiang 2019-09-02 12:31 ` Christoph Hellwig 2019-09-02 12:43 ` Gao Xiang 2019-09-01 5:51 ` [PATCH 21/21] erofs: save one level of indentation Gao Xiang 2019-09-02 12:31 ` Christoph Hellwig 2019-09-02 12:46 ` [PATCH 00/21] erofs: patchset addressing Christoph's comments Christoph Hellwig 2019-09-02 14:24 ` Gao Xiang 2019-09-02 15:23 ` Christoph Hellwig 2019-09-02 15:50 ` Gao Xiang 2019-09-03 6:58 ` Christoph Hellwig 2019-09-03 8:17 ` Gao Xiang 2019-09-03 15:37 ` Christoph Hellwig 2019-09-03 15:43 ` Gao Xiang 2019-09-04 2:08 ` [PATCH v2 00/25] " Gao Xiang 2019-09-04 2:08 ` [PATCH v2 01/25] erofs: remove all the byte offset comments Gao Xiang 2019-09-04 2:08 ` [PATCH v2 02/25] erofs: on-disk format should have explicitly assigned numbers Gao Xiang 2019-09-04 2:08 ` [PATCH v2 03/25] erofs: some macros are much more readable as a function Gao Xiang 2019-09-04 2:08 ` [PATCH v2 04/25] erofs: kill __packed for on-disk structures Gao Xiang 2019-09-04 2:08 ` [PATCH v2 05/25] erofs: update erofs_inode_is_data_compressed helper Gao Xiang 2019-09-04 2:08 ` [PATCH v2 06/25] erofs: use feature_incompat rather than requirements Gao Xiang 2019-09-04 2:08 ` [PATCH v2 07/25] erofs: better naming for erofs inode related stuffs Gao Xiang 2019-09-04 2:08 ` [PATCH v2 08/25] erofs: kill erofs_{init,exit}_inode_cache Gao Xiang 2019-09-04 2:08 ` [PATCH v2 09/25] erofs: use erofs_inode naming Gao Xiang 2019-09-04 2:08 ` [PATCH v2 10/25] erofs: update erofs_fs.h comments Gao Xiang 2019-09-04 2:08 ` [PATCH v2 11/25] erofs: update comments in inode.c Gao Xiang 2019-09-04 2:08 ` [PATCH v2 12/25] erofs: better erofs symlink stuffs Gao Xiang 2019-09-04 2:09 ` [PATCH v2 13/25] erofs: use dsb instead of layout for ondisk super_block Gao Xiang 2019-09-04 2:09 ` [PATCH v2 14/25] erofs: kill verbose debug info in erofs_fill_super Gao Xiang 2019-09-04 2:09 ` [PATCH v2 15/25] erofs: localize erofs_grab_bio() Gao Xiang 2019-09-04 2:09 ` [PATCH v2 16/25] erofs: kill prio and nofail of erofs_get_meta_page() Gao Xiang 2019-09-04 2:09 ` [PATCH v2 17/25] erofs: kill __submit_bio() Gao Xiang 2019-09-04 2:09 ` [PATCH v2 18/25] erofs: add "erofs_" prefix for common and short functions Gao Xiang 2019-09-04 2:09 ` [PATCH v2 19/25] erofs: kill all erofs specific fault injection Gao Xiang 2019-09-04 2:09 ` [PATCH v2 20/25] erofs: kill use_vmap module parameter Gao Xiang 2019-09-04 2:09 ` [PATCH v2 21/25] erofs: save one level of indentation Gao Xiang 2019-09-04 2:09 ` [PATCH v2 22/25] erofs: rename errln/infoln/debugln to erofs_{err, info, dbg} Gao Xiang 2019-09-04 2:09 ` [PATCH v2 23/25] erofs: use read_mapping_page instead of sb_bread Gao Xiang 2019-09-04 2:09 ` [PATCH v2 24/25] erofs: always use iget5_locked Gao Xiang 2019-09-04 2:09 ` [PATCH v2 25/25] erofs: use read_cache_page_gfp for erofs_get_meta_page Gao Xiang 2019-09-04 3:27 ` [PATCH v2 00/25] erofs: patchset addressing Christoph's comments Chao Yu 2019-09-05 1:03 ` Gao Xiang 2019-09-05 11:30 ` Christoph Hellwig 2019-09-04 5:16 ` Christoph Hellwig 2019-09-04 6:08 ` Gao Xiang
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