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author | Gao Xiang <hsiangkao@linux.alibaba.com> | 2021-12-28 13:46:00 +0800 |
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committer | Gao Xiang <hsiangkao@linux.alibaba.com> | 2021-12-29 06:41:59 +0800 |
commit | d67aee76d41861cda99b1ea13f8bf33fd06c5f20 (patch) | |
tree | 4083cf0207d04ff2962db1db3a1317e9c5340b61 /fs/erofs/decompressor.c | |
parent | 469407a3b5ed9390cfacb0363d1cc926a51f6a14 (diff) | |
download | linux-d67aee76d41861cda99b1ea13f8bf33fd06c5f20.tar.bz2 |
erofs: tidy up z_erofs_lz4_decompress
To prepare for the upcoming ztailpacking feature and further
cleanups, introduce a unique z_erofs_lz4_decompress_ctx to keep
the context, including inpages, outpages and oend, which are
frequently used by the lz4 decompressor.
No logic changes.
Link: https://lore.kernel.org/r/20211228054604.114518-2-hsiangkao@linux.alibaba.com
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Diffstat (limited to 'fs/erofs/decompressor.c')
-rw-r--r-- | fs/erofs/decompressor.c | 83 |
1 files changed, 44 insertions, 39 deletions
diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c index c373a199c407..ebb478ade10b 100644 --- a/fs/erofs/decompressor.c +++ b/fs/erofs/decompressor.c @@ -16,6 +16,14 @@ #define LZ4_DECOMPRESS_INPLACE_MARGIN(srcsize) (((srcsize) >> 8) + 32) #endif +struct z_erofs_lz4_decompress_ctx { + struct z_erofs_decompress_req *rq; + /* # of encoded, decoded pages */ + unsigned int inpages, outpages; + /* decoded block total length (used for in-place decompression) */ + unsigned int oend; +}; + int z_erofs_load_lz4_config(struct super_block *sb, struct erofs_super_block *dsb, struct z_erofs_lz4_cfgs *lz4, int size) @@ -56,11 +64,10 @@ int z_erofs_load_lz4_config(struct super_block *sb, * Fill all gaps with bounce pages if it's a sparse page list. Also check if * all physical pages are consecutive, which can be seen for moderate CR. */ -static int z_erofs_lz4_prepare_dstpages(struct z_erofs_decompress_req *rq, +static int z_erofs_lz4_prepare_dstpages(struct z_erofs_lz4_decompress_ctx *ctx, struct page **pagepool) { - const unsigned int nr = - PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT; + struct z_erofs_decompress_req *rq = ctx->rq; struct page *availables[LZ4_MAX_DISTANCE_PAGES] = { NULL }; unsigned long bounced[DIV_ROUND_UP(LZ4_MAX_DISTANCE_PAGES, BITS_PER_LONG)] = { 0 }; @@ -70,7 +77,7 @@ static int z_erofs_lz4_prepare_dstpages(struct z_erofs_decompress_req *rq, unsigned int i, j, top; top = 0; - for (i = j = 0; i < nr; ++i, ++j) { + for (i = j = 0; i < ctx->outpages; ++i, ++j) { struct page *const page = rq->out[i]; struct page *victim; @@ -112,41 +119,36 @@ static int z_erofs_lz4_prepare_dstpages(struct z_erofs_decompress_req *rq, return kaddr ? 1 : 0; } -static void *z_erofs_lz4_handle_inplace_io(struct z_erofs_decompress_req *rq, +static void *z_erofs_lz4_handle_overlap(struct z_erofs_lz4_decompress_ctx *ctx, void *inpage, unsigned int *inputmargin, int *maptype, bool support_0padding) { - unsigned int nrpages_in, nrpages_out; - unsigned int ofull, oend, inputsize, total, i, j; + struct z_erofs_decompress_req *rq = ctx->rq; + unsigned int omargin, total, i, j; struct page **in; void *src, *tmp; - inputsize = rq->inputsize; - nrpages_in = PAGE_ALIGN(inputsize) >> PAGE_SHIFT; - oend = rq->pageofs_out + rq->outputsize; - ofull = PAGE_ALIGN(oend); - nrpages_out = ofull >> PAGE_SHIFT; - if (rq->inplace_io) { + omargin = PAGE_ALIGN(ctx->oend) - ctx->oend; if (rq->partial_decoding || !support_0padding || - ofull - oend < LZ4_DECOMPRESS_INPLACE_MARGIN(inputsize)) + omargin < LZ4_DECOMPRESS_INPLACE_MARGIN(rq->inputsize)) goto docopy; - for (i = 0; i < nrpages_in; ++i) { + for (i = 0; i < ctx->inpages; ++i) { DBG_BUGON(rq->in[i] == NULL); - for (j = 0; j < nrpages_out - nrpages_in + i; ++j) + for (j = 0; j < ctx->outpages - ctx->inpages + i; ++j) if (rq->out[j] == rq->in[i]) goto docopy; } } - if (nrpages_in <= 1) { + if (ctx->inpages <= 1) { *maptype = 0; return inpage; } kunmap_atomic(inpage); might_sleep(); - src = erofs_vm_map_ram(rq->in, nrpages_in); + src = erofs_vm_map_ram(rq->in, ctx->inpages); if (!src) return ERR_PTR(-ENOMEM); *maptype = 1; @@ -155,7 +157,7 @@ static void *z_erofs_lz4_handle_inplace_io(struct z_erofs_decompress_req *rq, docopy: /* Or copy compressed data which can be overlapped to per-CPU buffer */ in = rq->in; - src = erofs_get_pcpubuf(nrpages_in); + src = erofs_get_pcpubuf(ctx->inpages); if (!src) { DBG_BUGON(1); kunmap_atomic(inpage); @@ -182,9 +184,10 @@ docopy: return src; } -static int z_erofs_lz4_decompress_mem(struct z_erofs_decompress_req *rq, +static int z_erofs_lz4_decompress_mem(struct z_erofs_lz4_decompress_ctx *ctx, u8 *out) { + struct z_erofs_decompress_req *rq = ctx->rq; unsigned int inputmargin; u8 *headpage, *src; bool support_0padding; @@ -210,8 +213,8 @@ static int z_erofs_lz4_decompress_mem(struct z_erofs_decompress_req *rq, } rq->inputsize -= inputmargin; - src = z_erofs_lz4_handle_inplace_io(rq, headpage, &inputmargin, - &maptype, support_0padding); + src = z_erofs_lz4_handle_overlap(ctx, headpage, &inputmargin, + &maptype, support_0padding); if (IS_ERR(src)) return PTR_ERR(src); @@ -240,9 +243,9 @@ static int z_erofs_lz4_decompress_mem(struct z_erofs_decompress_req *rq, } if (maptype == 0) { - kunmap_atomic(src); + kunmap_atomic(headpage); } else if (maptype == 1) { - vm_unmap_ram(src, PAGE_ALIGN(rq->inputsize) >> PAGE_SHIFT); + vm_unmap_ram(src, ctx->inpages); } else if (maptype == 2) { erofs_put_pcpubuf(src); } else { @@ -255,14 +258,18 @@ static int z_erofs_lz4_decompress_mem(struct z_erofs_decompress_req *rq, static int z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq, struct page **pagepool) { - const unsigned int nrpages_out = - PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT; + struct z_erofs_lz4_decompress_ctx ctx; unsigned int dst_maptype; void *dst; int ret; + ctx.rq = rq; + ctx.oend = rq->pageofs_out + rq->outputsize; + ctx.outpages = PAGE_ALIGN(ctx.oend) >> PAGE_SHIFT; + ctx.inpages = PAGE_ALIGN(rq->inputsize) >> PAGE_SHIFT; + /* one optimized fast path only for non bigpcluster cases yet */ - if (rq->inputsize <= PAGE_SIZE && nrpages_out == 1 && !rq->inplace_io) { + if (ctx.inpages == 1 && ctx.outpages == 1 && !rq->inplace_io) { DBG_BUGON(!*rq->out); dst = kmap_atomic(*rq->out); dst_maptype = 0; @@ -270,27 +277,25 @@ static int z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq, } /* general decoding path which can be used for all cases */ - ret = z_erofs_lz4_prepare_dstpages(rq, pagepool); - if (ret < 0) + ret = z_erofs_lz4_prepare_dstpages(&ctx, pagepool); + if (ret < 0) { return ret; - if (ret) { + } else if (ret > 0) { dst = page_address(*rq->out); dst_maptype = 1; - goto dstmap_out; + } else { + dst = erofs_vm_map_ram(rq->out, ctx.outpages); + if (!dst) + return -ENOMEM; + dst_maptype = 2; } - dst = erofs_vm_map_ram(rq->out, nrpages_out); - if (!dst) - return -ENOMEM; - dst_maptype = 2; - dstmap_out: - ret = z_erofs_lz4_decompress_mem(rq, dst + rq->pageofs_out); - + ret = z_erofs_lz4_decompress_mem(&ctx, dst + rq->pageofs_out); if (!dst_maptype) kunmap_atomic(dst); else if (dst_maptype == 2) - vm_unmap_ram(dst, nrpages_out); + vm_unmap_ram(dst, ctx.outpages); return ret; } |