static void zram_free_page(struct zram *zram, size_t index) { struct zram_meta *meta = zram->meta; unsigned long handle = meta->table[index].handle; u16 size = meta->table[index].size; if (unlikely(!handle)) { /* * No memory is allocated for zero filled pages. * Simply clear zero page flag. */ if (zram_test_flag(meta, index, ZRAM_ZERO)) { zram_clear_flag(meta, index, ZRAM_ZERO); zram->stats.pages_zero--; } return; } if (unlikely(size > max_zpage_size)) zram->stats.bad_compress--; zs_free(meta->mem_pool, handle); if (size <= PAGE_SIZE / 2) zram->stats.good_compress--; zram_stat64_sub(zram, &zram->stats.compr_size, meta->table[index].size); zram->stats.pages_stored--; meta->table[index].handle = 0; meta->table[index].size = 0; }
static int zram_decompress_page(struct zram *zram, char *mem, u32 index) { int ret = LZO_E_OK; size_t clen = PAGE_SIZE; unsigned char *cmem; struct zram_meta *meta = zram->meta; unsigned long handle = meta->table[index].handle; if (!handle || zram_test_flag(meta, index, ZRAM_ZERO)) { memset(mem, 0, PAGE_SIZE); return 0; } cmem = zs_map_object(meta->mem_pool, handle, ZS_MM_RO); if (meta->table[index].size == PAGE_SIZE) memcpy(mem, cmem, PAGE_SIZE); else ret = lzo1x_decompress_safe(cmem, meta->table[index].size, mem, &clen); zs_unmap_object(meta->mem_pool, handle); /* Should NEVER happen. Return bio error if it does. */ if (unlikely(ret != LZO_E_OK)) { pr_err("Decompression failed! err=%d, page=%u\n", ret, index); zram_stat64_inc(zram, &zram->stats.failed_reads); return ret; } return 0; }
static int zram_decompress_page(struct zram *zram, char *mem, u32 index) { int ret = LZO_E_OK; size_t clen = PAGE_SIZE; unsigned char *cmem; struct zram_meta *meta = zram->meta; unsigned long handle = meta->table[index].handle; if (!handle || zram_test_flag(meta, index, ZRAM_ZERO)) { memset(mem, 0, PAGE_SIZE); return 0; } cmem = zs_map_object(meta->mem_pool, handle, ZS_MM_RO); if (meta->table[index].size == PAGE_SIZE) memcpy(mem, cmem, PAGE_SIZE); else #ifdef CONFIG_MT_ENG_BUILD { /* Move to the start of bitstream */ cmem += GUIDE_BYTES_HALFLEN; #endif ret = lzo1x_decompress_safe(cmem, meta->table[index].size, mem, &clen); #ifdef CONFIG_MT_ENG_BUILD } #endif zs_unmap_object(meta->mem_pool, handle); /* Should NEVER happen. Return bio error if it does. */ if (unlikely(ret != LZO_E_OK)) { pr_err("Decompression failed! err=%d, page=%u\n", ret, index); zram_stat64_inc(zram, &zram->stats.failed_reads); #ifdef CONFIG_MT_ENG_BUILD { int idx; size_t tlen; printk(KERN_ALERT "\n@@@@@@@@@@\n"); tlen = meta->table[index].size + GUIDE_BYTES_LENGTH; cmem = zs_map_object(meta->mem_pool, handle, ZS_MM_RO); /* Head guide bytes */ for (idx = 0; idx < GUIDE_BYTES_HALFLEN; idx++) { printk(KERN_ALERT "%x ",(int)*cmem++); } printk(KERN_ALERT "\n=========\n"); for (;idx < tlen; idx++) { printk(KERN_ALERT "%x ",(int)*cmem++); } zs_unmap_object(meta->mem_pool, handle); printk(KERN_ALERT "\n!!!!!!!!!\n"); } #endif return ret; } return 0; }
static void zram_free_page(struct zram *zram, size_t index) { u32 clen; void *obj; struct page *page = zram->table[index].page; u32 offset = zram->table[index].offset; if (unlikely(!page)) { /* * No memory is allocated for zero filled pages. * Simply clear zero page flag. */ if (zram_test_flag(zram, index, ZRAM_ZERO)) { zram_clear_flag(zram, index, ZRAM_ZERO); zram_stat_dec(&zram->stats.pages_zero); } return; } if (unlikely(zram_test_flag(zram, index, ZRAM_UNCOMPRESSED))) { clen = PAGE_SIZE; __free_page(page); zram_clear_flag(zram, index, ZRAM_UNCOMPRESSED); zram_stat_dec(&zram->stats.pages_expand); goto out; } obj = kmap_atomic(page, KM_USER0) + offset; clen = xv_get_object_size(obj) - sizeof(struct zobj_header); kunmap_atomic(obj, KM_USER0); xv_free(zram->mem_pool, page, offset); if (clen <= PAGE_SIZE / 2) zram_stat_dec(&zram->stats.good_compress); out: zram_stat64_sub(zram, &zram->stats.compr_size, clen); zram_stat_dec(&zram->stats.pages_stored); zram->table[index].page = NULL; zram->table[index].offset = 0; }
static int zram_read_before_write(struct zram *zram, char *mem, u32 index) { int ret; size_t clen = PAGE_SIZE; struct zobj_header *zheader; unsigned char *cmem; if (zram_test_flag(zram, index, ZRAM_ZERO) || !zram->table[index].page) { memset(mem, 0, PAGE_SIZE); return 0; } cmem = kmap_atomic(zram->table[index].page, KM_USER0) + zram->table[index].offset; /* Page is stored uncompressed since it's incompressible */ if (unlikely(zram_test_flag(zram, index, ZRAM_UNCOMPRESSED))) { memcpy(mem, cmem, PAGE_SIZE); kunmap_atomic(cmem, KM_USER0); return 0; } ret = DECOMPRESS(cmem + sizeof(*zheader), xv_get_object_size(cmem) - sizeof(*zheader), mem, &clen); kunmap_atomic(cmem, KM_USER0); /* Should NEVER happen. Return bio error if it does. */ if (unlikely(ret)) { pr_err("Decompression failed! err=%d, page=%u\n", ret, index); zram_stat64_inc(zram, &zram->stats.failed_reads); return ret; } return 0; }
static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec, u32 index, int offset, struct bio *bio) { int ret; struct page *page; unsigned char *user_mem, *uncmem = NULL; struct zram_meta *meta = zram->meta; page = bvec->bv_page; if (unlikely(!meta->table[index].handle) || zram_test_flag(meta, index, ZRAM_ZERO)) { handle_zero_page(bvec); return 0; } if (is_partial_io(bvec)) /* Use a temporary buffer to decompress the page */ uncmem = kmalloc(PAGE_SIZE, GFP_NOIO); user_mem = kmap_atomic(page); if (!is_partial_io(bvec)) uncmem = user_mem; if (!uncmem) { pr_info("Unable to allocate temp memory\n"); ret = -ENOMEM; goto out_cleanup; } ret = zram_decompress_page(zram, uncmem, index); /* Should NEVER happen. Return bio error if it does. */ if (unlikely(ret != LZO_E_OK)) { pr_err("Decompression failed! err=%d, page=%u\n", ret, index); zram_stat64_inc(zram, &zram->stats.failed_reads); goto out_cleanup; } if (is_partial_io(bvec)) memcpy(user_mem + bvec->bv_offset, uncmem + offset, bvec->bv_len); flush_dcache_page(page); ret = 0; out_cleanup: kunmap_atomic(user_mem); if (is_partial_io(bvec)) kfree(uncmem); return ret; }
static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index, int offset) { int ret; u32 store_offset; size_t clen; struct zobj_header *zheader; struct page *page, *page_store; unsigned char *user_mem, *cmem, *src, *uncmem = NULL; page = bvec->bv_page; src = zram->compress_buffer; if (is_partial_io(bvec)) { /* * This is a partial IO. We need to read the full page * before to write the changes. */ uncmem = kmalloc(PAGE_SIZE, GFP_KERNEL); if (!uncmem) { pr_info("Error allocating temp memory!\n"); ret = -ENOMEM; goto out; } ret = zram_read_before_write(zram, uncmem, index); if (ret) { kfree(uncmem); goto out; } } /* * System overwrites unused sectors. Free memory associated * with this sector now. */ if (zram->table[index].page || zram_test_flag(zram, index, ZRAM_ZERO)) zram_free_page(zram, index); user_mem = kmap_atomic(page, KM_USER0); if (is_partial_io(bvec)) memcpy(uncmem + offset, user_mem + bvec->bv_offset, bvec->bv_len); else uncmem = user_mem; if (page_zero_filled(uncmem)) { kunmap_atomic(user_mem, KM_USER0); if (is_partial_io(bvec)) kfree(uncmem); zram_stat_inc(&zram->stats.pages_zero); zram_set_flag(zram, index, ZRAM_ZERO); ret = 0; goto out; } COMPRESS(uncmem, PAGE_SIZE, src, &clen, zram->compress_workmem); ret = 0; kunmap_atomic(user_mem, KM_USER0); if (is_partial_io(bvec)) kfree(uncmem); if (unlikely(ret != 0)) { pr_err("Compression failed! err=%d\n", ret); goto out; } /* * Page is incompressible. Store it as-is (uncompressed) * since we do not want to return too many disk write * errors which has side effect of hanging the system. */ if (unlikely(clen > max_zpage_size)) { clen = PAGE_SIZE; page_store = alloc_page(GFP_NOIO | __GFP_HIGHMEM); if (unlikely(!page_store)) { pr_info("Error allocating memory for " "incompressible page: %u\n", index); ret = -ENOMEM; goto out; } store_offset = 0; zram_set_flag(zram, index, ZRAM_UNCOMPRESSED); zram_stat_inc(&zram->stats.pages_expand); zram->table[index].page = page_store; src = kmap_atomic(page, KM_USER0); goto memstore; } if (xv_malloc(zram->mem_pool, clen + sizeof(*zheader), &zram->table[index].page, &store_offset, GFP_NOIO | __GFP_HIGHMEM)) { pr_info("Error allocating memory for compressed " "page: %u, size=%zu\n", index, clen); ret = -ENOMEM; goto out; } memstore: zram->table[index].offset = store_offset; cmem = kmap_atomic(zram->table[index].page, KM_USER1) + zram->table[index].offset; #if 0 /* Back-reference needed for memory defragmentation */ if (!zram_test_flag(zram, index, ZRAM_UNCOMPRESSED)) { zheader = (struct zobj_header *)cmem; zheader->table_idx = index; cmem += sizeof(*zheader); } #endif memcpy(cmem, src, clen); kunmap_atomic(cmem, KM_USER1); if (unlikely(zram_test_flag(zram, index, ZRAM_UNCOMPRESSED))) kunmap_atomic(src, KM_USER0); /* Update stats */ zram_stat64_add(zram, &zram->stats.compr_size, clen); zram_stat_inc(&zram->stats.pages_stored); if (clen <= PAGE_SIZE / 2) zram_stat_inc(&zram->stats.good_compress); return 0; out: if (ret) zram_stat64_inc(zram, &zram->stats.failed_writes); return ret; }
static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec, u32 index, int offset, struct bio *bio) { int ret; size_t clen; struct page *page; struct zobj_header *zheader; unsigned char *user_mem, *cmem, *uncmem = NULL; page = bvec->bv_page; if (zram_test_flag(zram, index, ZRAM_ZERO)) { handle_zero_page(bvec); return 0; } /* Requested page is not present in compressed area */ if (unlikely(!zram->table[index].page)) { pr_debug("Read before write: sector=%lu, size=%u", (ulong)(bio->bi_sector), bio->bi_size); handle_zero_page(bvec); return 0; } /* Page is stored uncompressed since it's incompressible */ if (unlikely(zram_test_flag(zram, index, ZRAM_UNCOMPRESSED))) { handle_uncompressed_page(zram, bvec, index, offset); return 0; } if (is_partial_io(bvec)) { /* Use a temporary buffer to decompress the page */ uncmem = kmalloc(PAGE_SIZE, GFP_KERNEL); if (!uncmem) { pr_info("Error allocating temp memory!\n"); return -ENOMEM; } } user_mem = kmap_atomic(page, KM_USER0); if (!is_partial_io(bvec)) uncmem = user_mem; clen = PAGE_SIZE; cmem = kmap_atomic(zram->table[index].page, KM_USER1) + zram->table[index].offset; ret = DECOMPRESS( cmem + sizeof(*zheader), xv_get_object_size(cmem) - sizeof(*zheader), uncmem, &clen); if (is_partial_io(bvec)) { memcpy(user_mem + bvec->bv_offset, uncmem + offset, bvec->bv_len); kfree(uncmem); } kunmap_atomic(cmem, KM_USER1); kunmap_atomic(user_mem, KM_USER0); /* Should NEVER happen. Return bio error if it does. */ if (unlikely(ret)) { pr_err("Decompression failed! err=%d, page=%u\n", ret, index); zram_stat64_inc(zram, &zram->stats.failed_reads); return ret; } flush_dcache_page(page); return 0; }
static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index, int offset) { int ret = 0; size_t clen; unsigned long handle; struct page *page; unsigned char *user_mem, *cmem, *src, *uncmem = NULL; struct zram_meta *meta = zram->meta; page = bvec->bv_page; src = meta->compress_buffer; if (is_partial_io(bvec)) { /* * This is a partial IO. We need to read the full page * before to write the changes. */ uncmem = kmalloc(PAGE_SIZE, GFP_NOIO); if (!uncmem) { ret = -ENOMEM; goto out; } ret = zram_decompress_page(zram, uncmem, index); if (ret) goto out; } /* * System overwrites unused sectors. Free memory associated * with this sector now. */ if (meta->table[index].handle || zram_test_flag(meta, index, ZRAM_ZERO)) zram_free_page(zram, index); user_mem = kmap_atomic(page); if (is_partial_io(bvec)) { memcpy(uncmem + offset, user_mem + bvec->bv_offset, bvec->bv_len); kunmap_atomic(user_mem); user_mem = NULL; } else { uncmem = user_mem; } if (page_zero_filled(uncmem)) { kunmap_atomic(user_mem); zram->stats.pages_zero++; zram_set_flag(meta, index, ZRAM_ZERO); ret = 0; goto out; } ret = lzo1x_1_compress(uncmem, PAGE_SIZE, src, &clen, meta->compress_workmem); if (!is_partial_io(bvec)) { kunmap_atomic(user_mem); user_mem = NULL; uncmem = NULL; } if (unlikely(ret != LZO_E_OK)) { pr_err("Compression failed! err=%d\n", ret); goto out; } if (unlikely(clen > max_zpage_size)) { zram->stats.bad_compress++; clen = PAGE_SIZE; src = NULL; if (is_partial_io(bvec)) src = uncmem; } handle = zs_malloc(meta->mem_pool, clen); if (!handle) { pr_info("Error allocating memory for compressed " "page: %u, size=%zu\n", index, clen); ret = -ENOMEM; goto out; } cmem = zs_map_object(meta->mem_pool, handle, ZS_MM_WO); if ((clen == PAGE_SIZE) && !is_partial_io(bvec)) src = kmap_atomic(page); memcpy(cmem, src, clen); if ((clen == PAGE_SIZE) && !is_partial_io(bvec)) kunmap_atomic(src); zs_unmap_object(meta->mem_pool, handle); meta->table[index].handle = handle; meta->table[index].size = clen; /* Update stats */ zram_stat64_add(zram, &zram->stats.compr_size, clen); zram->stats.pages_stored++; if (clen <= PAGE_SIZE / 2) zram->stats.good_compress++; out: if (is_partial_io(bvec)) kfree(uncmem); if (ret) zram_stat64_inc(zram, &zram->stats.failed_writes); return ret; }
static int zram_read(struct zram *zram, struct bio *bio) { int i; u32 index; struct bio_vec *bvec; if (unlikely(!zram->init_done)) { set_bit(BIO_UPTODATE, &bio->bi_flags); bio_endio(bio, 0); return 0; } zram_stat64_inc(zram, &zram->stats.num_reads); index = bio->bi_sector >> SECTORS_PER_PAGE_SHIFT; bio_for_each_segment(bvec, bio, i) { int ret; size_t clen; struct page *page; struct zobj_header *zheader; unsigned char *user_mem, *cmem; page = bvec->bv_page; if (zram_test_flag(zram, index, ZRAM_ZERO)) { handle_zero_page(page); index++; continue; } /* Requested page is not present in compressed area */ if (unlikely(!zram->table[index].page)) { pr_debug("Read before write: sector=%lu, size=%u", (ulong)(bio->bi_sector), bio->bi_size); /* Do nothing */ index++; continue; } /* Page is stored uncompressed since it's incompressible */ if (unlikely(zram_test_flag(zram, index, ZRAM_UNCOMPRESSED))) { handle_uncompressed_page(zram, page, index); index++; continue; } user_mem = kmap_atomic(page, KM_USER0); clen = PAGE_SIZE; cmem = kmap_atomic(zram->table[index].page, KM_USER1) + zram->table[index].offset; ret = lzo1x_decompress_safe( cmem + sizeof(*zheader), xv_get_object_size(cmem) - sizeof(*zheader), user_mem, &clen); kunmap_atomic(user_mem, KM_USER0); kunmap_atomic(cmem, KM_USER1); /* Should NEVER happen. Return bio error if it does. */ if (unlikely(ret != LZO_E_OK)) { pr_err("Decompression failed! err=%d, page=%u\n", ret, index); zram_stat64_inc(zram, &zram->stats.failed_reads); goto out; } flush_dcache_page(page); index++; }