From f466d5216404d611d6f9559bc97547edb7afa714 Mon Sep 17 00:00:00 2001 From: Gao Xiang Date: Wed, 6 Dec 2023 17:10:56 +0800 Subject: [PATCH] FROMGIT: erofs: refine z_erofs_transform_plain() for sub-page block support Sub-page block support is still unusable even with previous commits if interlaced PLAIN pclusters exist. Such pclusters can be found if the fragment feature is enabled. This commit tries to handle "the head part" of interlaced PLAIN pclusters first: it was once explained in commit fdffc091e6f9 ("erofs: support interlaced uncompressed data for compressed files"). It uses a unique way for both shifted and interlaced PLAIN pclusters. As an added bonus, PLAIN pclusters larger than the block size is also supported now for the upcoming large lclusters. Reviewed-by: Yue Hu Reviewed-by: Chao Yu Signed-off-by: Gao Xiang Link: https://lore.kernel.org/r/20231206091057.87027-5-hsiangkao@linux.alibaba.com Bug: 318378021 Change-Id: I3d50132664f8754f56d62744420060108ed0da4f (cherry picked from commit 192351616a9dde686492bcb9d1e4895a1411a527 https: //git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs.git dev) Signed-off-by: Sandeep Dhavale --- fs/erofs/decompressor.c | 82 ++++++++++++++++++++++++----------------- 1 file changed, 49 insertions(+), 33 deletions(-) diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c index 024e0b4733e8..38c7f9c96c68 100644 --- a/fs/erofs/decompressor.c +++ b/fs/erofs/decompressor.c @@ -321,43 +321,59 @@ dstmap_out: static int z_erofs_transform_plain(struct z_erofs_decompress_req *rq, struct page **pagepool) { - const unsigned int inpages = PAGE_ALIGN(rq->inputsize) >> PAGE_SHIFT; - const unsigned int outpages = + const unsigned int nrpages_in = + PAGE_ALIGN(rq->pageofs_in + rq->inputsize) >> PAGE_SHIFT; + const unsigned int nrpages_out = PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT; - const unsigned int righthalf = min_t(unsigned int, rq->outputsize, - PAGE_SIZE - rq->pageofs_out); - const unsigned int lefthalf = rq->outputsize - righthalf; - const unsigned int interlaced_offset = - rq->alg == Z_EROFS_COMPRESSION_SHIFTED ? 0 : rq->pageofs_out; - u8 *src; + const unsigned int bs = rq->sb->s_blocksize; + unsigned int cur = 0, ni = 0, no, pi, po, insz, cnt; + u8 *kin; - if (outpages > 2 && rq->alg == Z_EROFS_COMPRESSION_SHIFTED) { - DBG_BUGON(1); - return -EFSCORRUPTED; - } - - if (rq->out[0] == *rq->in) { - DBG_BUGON(rq->pageofs_out); - return 0; - } - - src = kmap_local_page(rq->in[inpages - 1]) + rq->pageofs_in; - if (rq->out[0]) - memcpy_to_page(rq->out[0], rq->pageofs_out, - src + interlaced_offset, righthalf); - - if (outpages > inpages) { - DBG_BUGON(!rq->out[outpages - 1]); - if (rq->out[outpages - 1] != rq->in[inpages - 1]) { - memcpy_to_page(rq->out[outpages - 1], 0, src + - (interlaced_offset ? 0 : righthalf), - lefthalf); - } else if (!interlaced_offset) { - memmove(src, src + righthalf, lefthalf); - flush_dcache_page(rq->in[inpages - 1]); + DBG_BUGON(rq->outputsize > rq->inputsize); + if (rq->alg == Z_EROFS_COMPRESSION_INTERLACED) { + cur = bs - (rq->pageofs_out & (bs - 1)); + pi = (rq->pageofs_in + rq->inputsize - cur) & ~PAGE_MASK; + cur = min(cur, rq->outputsize); + if (cur && rq->out[0]) { + kin = kmap_local_page(rq->in[nrpages_in - 1]); + if (rq->out[0] == rq->in[nrpages_in - 1]) { + memmove(kin + rq->pageofs_out, kin + pi, cur); + flush_dcache_page(rq->out[0]); + } else { + memcpy_to_page(rq->out[0], rq->pageofs_out, + kin + pi, cur); + } + kunmap_local(kin); } + rq->outputsize -= cur; } - kunmap_local(src); + + for (; rq->outputsize; rq->pageofs_in = 0, cur += PAGE_SIZE, ni++) { + insz = min_t(unsigned int, PAGE_SIZE - rq->pageofs_in, + rq->outputsize); + rq->outputsize -= insz; + if (!rq->in[ni]) + continue; + kin = kmap_local_page(rq->in[ni]); + pi = 0; + do { + no = (rq->pageofs_out + cur + pi) >> PAGE_SHIFT; + po = (rq->pageofs_out + cur + pi) & ~PAGE_MASK; + DBG_BUGON(no >= nrpages_out); + cnt = min_t(unsigned int, insz - pi, PAGE_SIZE - po); + if (rq->out[no] == rq->in[ni]) { + memmove(kin + po, + kin + rq->pageofs_in + pi, cnt); + flush_dcache_page(rq->out[no]); + } else if (rq->out[no]) { + memcpy_to_page(rq->out[no], po, + kin + rq->pageofs_in + pi, cnt); + } + pi += cnt; + } while (pi < insz); + kunmap_local(kin); + } + DBG_BUGON(ni > nrpages_in); return 0; }