diff options
Diffstat (limited to 'fs/erofs/decompressor.c')
-rw-r--r-- | fs/erofs/decompressor.c | 272 |
1 files changed, 168 insertions, 104 deletions
diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c index 1cb1ffd10569..88e33addf229 100644 --- a/fs/erofs/decompressor.c +++ b/fs/erofs/decompressor.c @@ -28,6 +28,42 @@ struct z_erofs_decompressor { char *name; }; +int z_erofs_load_lz4_config(struct super_block *sb, + struct erofs_super_block *dsb, + struct z_erofs_lz4_cfgs *lz4, int size) +{ + struct erofs_sb_info *sbi = EROFS_SB(sb); + u16 distance; + + if (lz4) { + if (size < sizeof(struct z_erofs_lz4_cfgs)) { + erofs_err(sb, "invalid lz4 cfgs, size=%u", size); + return -EINVAL; + } + distance = le16_to_cpu(lz4->max_distance); + + sbi->lz4.max_pclusterblks = le16_to_cpu(lz4->max_pclusterblks); + if (!sbi->lz4.max_pclusterblks) { + sbi->lz4.max_pclusterblks = 1; /* reserved case */ + } else if (sbi->lz4.max_pclusterblks > + Z_EROFS_PCLUSTER_MAX_SIZE / EROFS_BLKSIZ) { + erofs_err(sb, "too large lz4 pclusterblks %u", + sbi->lz4.max_pclusterblks); + return -EINVAL; + } else if (sbi->lz4.max_pclusterblks >= 2) { + erofs_info(sb, "EXPERIMENTAL big pcluster feature in use. Use at your own risk!"); + } + } else { + distance = le16_to_cpu(dsb->u1.lz4_max_distance); + sbi->lz4.max_pclusterblks = 1; + } + + sbi->lz4.max_distance_pages = distance ? + DIV_ROUND_UP(distance, PAGE_SIZE) + 1 : + LZ4_MAX_DISTANCE_PAGES; + return erofs_pcpubuf_growsize(sbi->lz4.max_pclusterblks); +} + static int z_erofs_lz4_prepare_destpages(struct z_erofs_decompress_req *rq, struct list_head *pagepool) { @@ -36,6 +72,8 @@ static int z_erofs_lz4_prepare_destpages(struct z_erofs_decompress_req *rq, struct page *availables[LZ4_MAX_DISTANCE_PAGES] = { NULL }; unsigned long bounced[DIV_ROUND_UP(LZ4_MAX_DISTANCE_PAGES, BITS_PER_LONG)] = { 0 }; + unsigned int lz4_max_distance_pages = + EROFS_SB(rq->sb)->lz4.max_distance_pages; void *kaddr = NULL; unsigned int i, j, top; @@ -44,14 +82,14 @@ static int z_erofs_lz4_prepare_destpages(struct z_erofs_decompress_req *rq, struct page *const page = rq->out[i]; struct page *victim; - if (j >= LZ4_MAX_DISTANCE_PAGES) + if (j >= lz4_max_distance_pages) j = 0; /* 'valid' bounced can only be tested after a complete round */ if (test_bit(j, bounced)) { - DBG_BUGON(i < LZ4_MAX_DISTANCE_PAGES); - DBG_BUGON(top >= LZ4_MAX_DISTANCE_PAGES); - availables[top++] = rq->out[i - LZ4_MAX_DISTANCE_PAGES]; + DBG_BUGON(i < lz4_max_distance_pages); + DBG_BUGON(top >= lz4_max_distance_pages); + availables[top++] = rq->out[i - lz4_max_distance_pages]; } if (page) { @@ -73,9 +111,8 @@ static int z_erofs_lz4_prepare_destpages(struct z_erofs_decompress_req *rq, victim = availables[--top]; get_page(victim); } else { - victim = erofs_allocpage(pagepool, GFP_KERNEL); - if (!victim) - return -ENOMEM; + victim = erofs_allocpage(pagepool, + GFP_KERNEL | __GFP_NOFAIL); set_page_private(victim, Z_EROFS_SHORTLIVED_PAGE); } rq->out[i] = victim; @@ -83,96 +120,123 @@ static int z_erofs_lz4_prepare_destpages(struct z_erofs_decompress_req *rq, return kaddr ? 1 : 0; } -static void *generic_copy_inplace_data(struct z_erofs_decompress_req *rq, - u8 *src, unsigned int pageofs_in) +static void *z_erofs_handle_inplace_io(struct z_erofs_decompress_req *rq, + void *inpage, unsigned int *inputmargin, int *maptype, + bool support_0padding) { - /* - * if in-place decompression is ongoing, those decompressed - * pages should be copied in order to avoid being overlapped. - */ - struct page **in = rq->in; - u8 *const tmp = erofs_get_pcpubuf(0); - u8 *tmpp = tmp; - unsigned int inlen = rq->inputsize - pageofs_in; - unsigned int count = min_t(uint, inlen, PAGE_SIZE - pageofs_in); - - while (tmpp < tmp + inlen) { - if (!src) - src = kmap_atomic(*in); - memcpy(tmpp, src + pageofs_in, count); - kunmap_atomic(src); - src = NULL; - tmpp += count; - pageofs_in = 0; - count = PAGE_SIZE; + unsigned int nrpages_in, nrpages_out; + unsigned int ofull, oend, inputsize, 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) { + if (rq->partial_decoding || !support_0padding || + ofull - oend < LZ4_DECOMPRESS_INPLACE_MARGIN(inputsize)) + goto docopy; + + for (i = 0; i < nrpages_in; ++i) { + DBG_BUGON(rq->in[i] == NULL); + for (j = 0; j < nrpages_out - nrpages_in + i; ++j) + if (rq->out[j] == rq->in[i]) + goto docopy; + } + } + + if (nrpages_in <= 1) { + *maptype = 0; + return inpage; + } + kunmap_atomic(inpage); + might_sleep(); + src = erofs_vm_map_ram(rq->in, nrpages_in); + if (!src) + return ERR_PTR(-ENOMEM); + *maptype = 1; + return src; + +docopy: + /* Or copy compressed data which can be overlapped to per-CPU buffer */ + in = rq->in; + src = erofs_get_pcpubuf(nrpages_in); + if (!src) { + DBG_BUGON(1); + kunmap_atomic(inpage); + return ERR_PTR(-EFAULT); + } + + tmp = src; + total = rq->inputsize; + while (total) { + unsigned int page_copycnt = + min_t(unsigned int, total, PAGE_SIZE - *inputmargin); + + if (!inpage) + inpage = kmap_atomic(*in); + memcpy(tmp, inpage + *inputmargin, page_copycnt); + kunmap_atomic(inpage); + inpage = NULL; + tmp += page_copycnt; + total -= page_copycnt; ++in; + *inputmargin = 0; } - return tmp; + *maptype = 2; + return src; } static int z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq, u8 *out) { - unsigned int inputmargin, inlen; - u8 *src; - bool copied, support_0padding; - int ret; - - if (rq->inputsize > PAGE_SIZE) - return -EOPNOTSUPP; + unsigned int inputmargin; + u8 *headpage, *src; + bool support_0padding; + int ret, maptype; - src = kmap_atomic(*rq->in); + DBG_BUGON(*rq->in == NULL); + headpage = kmap_atomic(*rq->in); inputmargin = 0; support_0padding = false; /* decompression inplace is only safe when 0padding is enabled */ - if (EROFS_SB(rq->sb)->feature_incompat & - EROFS_FEATURE_INCOMPAT_LZ4_0PADDING) { + if (erofs_sb_has_lz4_0padding(EROFS_SB(rq->sb))) { support_0padding = true; - while (!src[inputmargin & ~PAGE_MASK]) + while (!headpage[inputmargin & ~PAGE_MASK]) if (!(++inputmargin & ~PAGE_MASK)) break; if (inputmargin >= rq->inputsize) { - kunmap_atomic(src); + kunmap_atomic(headpage); return -EIO; } } - copied = false; - inlen = rq->inputsize - inputmargin; - if (rq->inplace_io) { - 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; - } - } + rq->inputsize -= inputmargin; + src = z_erofs_handle_inplace_io(rq, headpage, &inputmargin, &maptype, + support_0padding); + if (IS_ERR(src)) + return PTR_ERR(src); /* legacy format could compress extra data in a pcluster. */ if (rq->partial_decoding || !support_0padding) ret = LZ4_decompress_safe_partial(src + inputmargin, out, - inlen, rq->outputsize, - rq->outputsize); + rq->inputsize, rq->outputsize, rq->outputsize); else ret = LZ4_decompress_safe(src + inputmargin, out, - inlen, rq->outputsize); + rq->inputsize, rq->outputsize); if (ret != rq->outputsize) { erofs_err(rq->sb, "failed to decompress %d in[%u, %u] out[%u]", - ret, inlen, inputmargin, rq->outputsize); + ret, rq->inputsize, inputmargin, rq->outputsize); WARN_ON(1); print_hex_dump(KERN_DEBUG, "[ in]: ", DUMP_PREFIX_OFFSET, - 16, 1, src + inputmargin, inlen, true); + 16, 1, src + inputmargin, rq->inputsize, true); print_hex_dump(KERN_DEBUG, "[out]: ", DUMP_PREFIX_OFFSET, 16, 1, out, rq->outputsize, true); @@ -181,10 +245,16 @@ static int z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq, u8 *out) ret = -EIO; } - if (copied) - erofs_put_pcpubuf(src); - else + if (maptype == 0) { kunmap_atomic(src); + } else if (maptype == 1) { + vm_unmap_ram(src, PAGE_ALIGN(rq->inputsize) >> PAGE_SHIFT); + } else if (maptype == 2) { + erofs_put_pcpubuf(src); + } else { + DBG_BUGON(1); + return -EFAULT; + } return ret; } @@ -234,57 +304,51 @@ static int z_erofs_decompress_generic(struct z_erofs_decompress_req *rq, const struct z_erofs_decompressor *alg = decompressors + rq->alg; unsigned int dst_maptype; void *dst; - int ret, i; + int ret; - if (nrpages_out == 1 && !rq->inplace_io) { - DBG_BUGON(!*rq->out); - dst = kmap_atomic(*rq->out); - dst_maptype = 0; - goto dstmap_out; - } + /* two optimized fast paths only for non bigpcluster cases yet */ + if (rq->inputsize <= PAGE_SIZE) { + if (nrpages_out == 1 && !rq->inplace_io) { + DBG_BUGON(!*rq->out); + dst = kmap_atomic(*rq->out); + dst_maptype = 0; + goto dstmap_out; + } - /* - * For the case of small output size (especially much less - * than PAGE_SIZE), memcpy the decompressed data rather than - * compressed data is preferred. - */ - if (rq->outputsize <= PAGE_SIZE * 7 / 8) { - dst = erofs_get_pcpubuf(0); - if (IS_ERR(dst)) - return PTR_ERR(dst); - - rq->inplace_io = false; - ret = alg->decompress(rq, dst); - if (!ret) - copy_from_pcpubuf(rq->out, dst, rq->pageofs_out, - rq->outputsize); - - erofs_put_pcpubuf(dst); - return ret; + /* + * For the case of small output size (especially much less + * than PAGE_SIZE), memcpy the decompressed data rather than + * compressed data is preferred. + */ + if (rq->outputsize <= PAGE_SIZE * 7 / 8) { + dst = erofs_get_pcpubuf(1); + if (IS_ERR(dst)) + return PTR_ERR(dst); + + rq->inplace_io = false; + ret = alg->decompress(rq, dst); + if (!ret) + copy_from_pcpubuf(rq->out, dst, rq->pageofs_out, + rq->outputsize); + + erofs_put_pcpubuf(dst); + return ret; + } } + /* general decoding path which can be used for all cases */ ret = alg->prepare_destpages(rq, pagepool); - if (ret < 0) { + if (ret < 0) return ret; - } else if (ret) { + if (ret) { dst = page_address(*rq->out); dst_maptype = 1; goto dstmap_out; } - i = 0; - while (1) { - dst = vm_map_ram(rq->out, nrpages_out, -1); - - /* retry two more times (totally 3 times) */ - if (dst || ++i >= 3) - break; - vm_unmap_aliases(); - } - + dst = erofs_vm_map_ram(rq->out, nrpages_out); if (!dst) return -ENOMEM; - dst_maptype = 2; dstmap_out: |