On Tue, Oct 18, 2022 at 01:55:25PM +0900, Sergey Senozhatsky wrote: > The patch turns compression streams and compressor algorithm > name struct zram members into arrays, so that we can have > multiple compression streams support (in the next patches). > > The patch uses a rather explicit API for compressor selection: > > - Get primary (default) compression stream > zcomp_stream_get(zram->comps[ZRAM_PRIMARY_ZCOMP]) > - Get secondary compression stream > zcomp_stream_get(zram->comps[ZRAM_SECONDARY_ZCOMP]) > > We use similar API for compression streams put(). > > At this point we always have just one compression stream, > since CONFIG_ZRAM_MULTI_COMP is not yet defined. > > Signed-off-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx> > --- > drivers/block/zram/zcomp.c | 6 +-- > drivers/block/zram/zcomp.h | 2 +- > drivers/block/zram/zram_drv.c | 87 ++++++++++++++++++++++++----------- > drivers/block/zram/zram_drv.h | 14 +++++- > 4 files changed, 77 insertions(+), 32 deletions(-) > > diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c > index 0916de952e09..55af4efd7983 100644 > --- a/drivers/block/zram/zcomp.c > +++ b/drivers/block/zram/zcomp.c > @@ -206,7 +206,7 @@ void zcomp_destroy(struct zcomp *comp) > * case of allocation error, or any other error potentially > * returned by zcomp_init(). > */ > -struct zcomp *zcomp_create(const char *compress) > +struct zcomp *zcomp_create(const char *alg) > { > struct zcomp *comp; > int error; > @@ -216,14 +216,14 @@ struct zcomp *zcomp_create(const char *compress) > * is not loaded yet. We must do it here, otherwise we are about to > * call /sbin/modprobe under CPU hot-plug lock. > */ > - if (!zcomp_available_algorithm(compress)) > + if (!zcomp_available_algorithm(alg)) > return ERR_PTR(-EINVAL); > > comp = kzalloc(sizeof(struct zcomp), GFP_KERNEL); > if (!comp) > return ERR_PTR(-ENOMEM); > > - comp->name = compress; > + comp->name = alg; > error = zcomp_init(comp); > if (error) { > kfree(comp); > diff --git a/drivers/block/zram/zcomp.h b/drivers/block/zram/zcomp.h > index 40f6420f4b2e..cdefdef93da8 100644 > --- a/drivers/block/zram/zcomp.h > +++ b/drivers/block/zram/zcomp.h > @@ -27,7 +27,7 @@ int zcomp_cpu_dead(unsigned int cpu, struct hlist_node *node); > ssize_t zcomp_available_show(const char *comp, char *buf); > bool zcomp_available_algorithm(const char *comp); > > -struct zcomp *zcomp_create(const char *comp); > +struct zcomp *zcomp_create(const char *alg); > void zcomp_destroy(struct zcomp *comp); > > struct zcomp_strm *zcomp_stream_get(struct zcomp *comp); > diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c > index 966aab902d19..770ea3489eb6 100644 > --- a/drivers/block/zram/zram_drv.c > +++ b/drivers/block/zram/zram_drv.c > @@ -1007,36 +1007,53 @@ static ssize_t comp_algorithm_show(struct device *dev, > struct zram *zram = dev_to_zram(dev); > > down_read(&zram->init_lock); > - sz = zcomp_available_show(zram->compressor, buf); > + sz = zcomp_available_show(zram->comp_algs[ZRAM_PRIMARY_ZCOMP], buf); > up_read(&zram->init_lock); > > return sz; > } > > +static void comp_algorithm_set(struct zram *zram, u32 idx, const char *alg) > +{ > + /* Do not kfree() algs that we didn't allocate, IOW the default ones */ > + if (zram->comp_algs[idx] != default_compressor) > + kfree(zram->comp_algs[idx]); > + zram->comp_algs[idx] = alg; > +} > + > static ssize_t comp_algorithm_store(struct device *dev, > struct device_attribute *attr, const char *buf, size_t len) > { > struct zram *zram = dev_to_zram(dev); > - char compressor[ARRAY_SIZE(zram->compressor)]; > + char *compressor; > size_t sz; > > - strscpy(compressor, buf, sizeof(compressor)); > + sz = strlen(buf); > + if (sz >= CRYPTO_MAX_ALG_NAME) > + return -E2BIG; > + > + compressor = kstrdup(buf, GFP_KERNEL); > + if (!compressor) > + return -ENOMEM; > + > /* ignore trailing newline */ > - sz = strlen(compressor); > if (sz > 0 && compressor[sz - 1] == '\n') > compressor[sz - 1] = 0x00; > > - if (!zcomp_available_algorithm(compressor)) > + if (!zcomp_available_algorithm(compressor)) { > + kfree(compressor); > return -EINVAL; > + } > > down_write(&zram->init_lock); > if (init_done(zram)) { > up_write(&zram->init_lock); > + kfree(compressor); > pr_info("Can't change algorithm for initialized device\n"); > return -EBUSY; > } > > - strcpy(zram->compressor, compressor); > + comp_algorithm_set(zram, ZRAM_PRIMARY_ZCOMP, compressor); > up_write(&zram->init_lock); > return len; > } > @@ -1284,7 +1301,7 @@ static int __zram_bvec_read(struct zram *zram, struct page *page, u32 index, > size = zram_get_obj_size(zram, index); > > if (size != PAGE_SIZE) > - zstrm = zcomp_stream_get(zram->comp); > + zstrm = zcomp_stream_get(zram->comps[ZRAM_PRIMARY_ZCOMP]); > > src = zs_map_object(zram->mem_pool, handle, ZS_MM_RO); > if (size == PAGE_SIZE) { > @@ -1296,7 +1313,7 @@ static int __zram_bvec_read(struct zram *zram, struct page *page, u32 index, > dst = kmap_atomic(page); > ret = zcomp_decompress(zstrm, src, size, dst); > kunmap_atomic(dst); > - zcomp_stream_put(zram->comp); > + zcomp_stream_put(zram->comps[ZRAM_PRIMARY_ZCOMP]); > } > zs_unmap_object(zram->mem_pool, handle); > zram_slot_unlock(zram, index); > @@ -1363,13 +1380,13 @@ static int __zram_bvec_write(struct zram *zram, struct bio_vec *bvec, > kunmap_atomic(mem); > > compress_again: > - zstrm = zcomp_stream_get(zram->comp); > + zstrm = zcomp_stream_get(zram->comps[ZRAM_PRIMARY_ZCOMP]); > src = kmap_atomic(page); > ret = zcomp_compress(zstrm, src, &comp_len); > kunmap_atomic(src); > > if (unlikely(ret)) { > - zcomp_stream_put(zram->comp); > + zcomp_stream_put(zram->comps[ZRAM_PRIMARY_ZCOMP]); > pr_err("Compression failed! err=%d\n", ret); > zs_free(zram->mem_pool, handle); > return ret; > @@ -1397,7 +1414,7 @@ static int __zram_bvec_write(struct zram *zram, struct bio_vec *bvec, > __GFP_HIGHMEM | > __GFP_MOVABLE); > if (IS_ERR((void *)handle)) { > - zcomp_stream_put(zram->comp); > + zcomp_stream_put(zram->comps[ZRAM_PRIMARY_ZCOMP]); > atomic64_inc(&zram->stats.writestall); > handle = zs_malloc(zram->mem_pool, comp_len, > GFP_NOIO | __GFP_HIGHMEM | > @@ -1414,14 +1431,14 @@ static int __zram_bvec_write(struct zram *zram, struct bio_vec *bvec, > * zstrm buffer back. It is necessary that the dereferencing > * of the zstrm variable below occurs correctly. > */ > - zstrm = zcomp_stream_get(zram->comp); > + zstrm = zcomp_stream_get(zram->comps[ZRAM_PRIMARY_ZCOMP]); > } > > alloced_pages = zs_get_total_pages(zram->mem_pool); > update_used_max(zram, alloced_pages); > > if (zram->limit_pages && alloced_pages > zram->limit_pages) { > - zcomp_stream_put(zram->comp); > + zcomp_stream_put(zram->comps[ZRAM_PRIMARY_ZCOMP]); > zs_free(zram->mem_pool, handle); > return -ENOMEM; > } > @@ -1435,7 +1452,7 @@ static int __zram_bvec_write(struct zram *zram, struct bio_vec *bvec, > if (comp_len == PAGE_SIZE) > kunmap_atomic(src); > > - zcomp_stream_put(zram->comp); > + zcomp_stream_put(zram->comps[ZRAM_PRIMARY_ZCOMP]); > zs_unmap_object(zram->mem_pool, handle); > atomic64_add(comp_len, &zram->stats.compr_data_size); > out: > @@ -1710,6 +1727,20 @@ static int zram_rw_page(struct block_device *bdev, sector_t sector, > return ret; > } > > +static void zram_destroy_comps(struct zram *zram) > +{ > + u32 idx; > + > + for (idx = 0; idx < ZRAM_MAX_ZCOMPS; idx++) { > + struct zcomp *comp = zram->comps[idx]; > + > + zram->comps[idx] = NULL; > + if (IS_ERR_OR_NULL(comp)) nit: Why don't you use just NULL check? I don't see any error setting for zram->comps(Maybe later patch? Will keep check)?