Update zram and zcomp read (decompress) path to provide a zstrm to backends that set ZCOMP_NEED_READ_ZSTRM bit in flags, so now we can enable ZLIB compression backend in Kconfig.
Signed-off-by: Sergey Senozhatsky <[email protected]> --- drivers/block/zram/Kconfig | 14 +++++++++++++- drivers/block/zram/zcomp.c | 7 ++++++- drivers/block/zram/zram_drv.c | 23 +++++++++++++++++++---- 3 files changed, 38 insertions(+), 6 deletions(-) diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig index 386ba3d..1858762 100644 --- a/drivers/block/zram/Kconfig +++ b/drivers/block/zram/Kconfig @@ -23,4 +23,16 @@ config ZRAM_LZ4_COMPRESS default n help This option enables LZ4 compression algorithm support. Compression - algorithm can be changed using `comp_algorithm' device attribute. \ No newline at end of file + algorithm can be changed using `comp_algorithm' device attribute. + +config ZRAM_ZLIB_COMPRESS + bool "Enable ZLIB algorithm support" + depends on ZRAM + select ZLIB_INFLATE + select ZLIB_DEFLATE + default n + help + This option enables ZLIB compression algorithm support. ZLIB gives + a significantly better compression ratio, at a price of significantly + worse performance. Compression algorithm can be changed using + `comp_algorithm' device attribute. diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c index a0cef0b..8f24820 100644 --- a/drivers/block/zram/zcomp.c +++ b/drivers/block/zram/zcomp.c @@ -323,7 +323,12 @@ int zcomp_decompress(struct zcomp *comp, struct zcomp_strm *zstrm, const unsigned char *src, size_t src_len, unsigned char *dst) { - return comp->backend->decompress(src, src_len, dst, NULL); + void *private = NULL; + + if (unlikely(zstrm)) + private = zstrm->private; + + return comp->backend->decompress(src, src_len, dst, private); } void zcomp_destroy(struct zcomp *comp) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 0aec4ce..5c52400 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -560,7 +560,8 @@ static void zram_free_page(struct zram *zram, size_t index) zram_set_obj_size(meta, index, 0); } -static int zram_decompress_page(struct zram *zram, char *mem, u32 index) +static int zram_decompress_page(struct zram *zram, struct zcomp_strm *zstrm, + char *mem, u32 index) { int ret = 0; unsigned char *cmem; @@ -582,7 +583,7 @@ static int zram_decompress_page(struct zram *zram, char *mem, u32 index) if (size == PAGE_SIZE) copy_page(mem, cmem); else - ret = zcomp_decompress(zram->comp, NULL, cmem, size, mem); + ret = zcomp_decompress(zram->comp, zstrm, cmem, size, mem); zs_unmap_object(meta->mem_pool, handle); bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value); @@ -602,6 +603,7 @@ static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec, struct page *page; unsigned char *user_mem, *uncmem = NULL; struct zram_meta *meta = zram->meta; + void *dzstrm; page = bvec->bv_page; bit_spin_lock(ZRAM_ACCESS, &meta->table[index].value); @@ -617,6 +619,7 @@ static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec, /* Use a temporary buffer to decompress the page */ uncmem = kmalloc(PAGE_SIZE, GFP_NOIO); + dzstrm = zcomp_decompress_begin(zram->comp); user_mem = kmap_atomic(page); if (!is_partial_io(bvec)) uncmem = user_mem; @@ -627,7 +630,11 @@ static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec, goto out_cleanup; } - ret = zram_decompress_page(zram, uncmem, index); + ret = zram_decompress_page(zram, dzstrm, uncmem, index); + + zcomp_decompress_end(zram->comp, dzstrm); + dzstrm = NULL; + /* Should NEVER happen. Return bio error if it does. */ if (unlikely(ret)) goto out_cleanup; @@ -638,10 +645,13 @@ static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec, flush_dcache_page(page); ret = 0; + out_cleanup: kunmap_atomic(user_mem); + zcomp_decompress_end(zram->comp, dzstrm); if (is_partial_io(bvec)) kfree(uncmem); + return ret; } @@ -659,6 +669,8 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index, page = bvec->bv_page; if (is_partial_io(bvec)) { + void *dzstrm; + /* * This is a partial IO. We need to read the full page * before to write the changes. @@ -668,7 +680,10 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index, ret = -ENOMEM; goto out; } - ret = zram_decompress_page(zram, uncmem, index); + + dzstrm = zcomp_decompress_begin(zram->comp); + ret = zram_decompress_page(zram, dzstrm, uncmem, index); + zcomp_decompress_end(zram->comp, dzstrm); if (ret) goto out; } -- 2.5.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
