[PATCH 3/3] zram: use common zpool interface
From: Vitaly Wool
Date: Thu Oct 10 2019 - 16:20:36 EST
Change ZRAM into using zpool API. This patch allows to use any
zpool compatible allocation backend with ZRAM. It is meant to make
no functional changes to ZRAM.
zpool-registered backend can be selected via the module parameter
or kernel boot string. 'zsmalloc' is taken by default.
Signed-off-by: Vitaly Wool <vitalywool@xxxxxxxxx>
---
drivers/block/zram/Kconfig | 3 ++-
drivers/block/zram/zram_drv.c | 64 +++++++++++++++++++----------------
drivers/block/zram/zram_drv.h | 4 +--
3 files changed, 39 insertions(+), 32 deletions(-)
diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig
index fe7a4b7d30cf..7248d5aa3468 100644
--- a/drivers/block/zram/Kconfig
+++ b/drivers/block/zram/Kconfig
@@ -1,8 +1,9 @@
# SPDX-License-Identifier: GPL-2.0
config ZRAM
tristate "Compressed RAM block device support"
- depends on BLOCK && SYSFS && ZSMALLOC && CRYPTO
+ depends on BLOCK && SYSFS && CRYPTO
select CRYPTO_LZO
+ select ZPOOL
help
Creates virtual block devices called /dev/zramX (X = 0, 1, ...).
Pages written to these disks are compressed and stored in memory
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index d58a359a6622..881f10f99a5d 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -43,6 +43,9 @@ static DEFINE_MUTEX(zram_index_mutex);
static int zram_major;
static const char *default_compressor = "lzo-rle";
+#define BACKEND_PAR_BUF_SIZE 32
+static char backend_par_buf[BACKEND_PAR_BUF_SIZE];
+
/* Module params (documentation at end) */
static unsigned int num_devices = 1;
/*
@@ -277,7 +280,7 @@ static ssize_t mem_used_max_store(struct device *dev,
down_read(&zram->init_lock);
if (init_done(zram)) {
atomic_long_set(&zram->stats.max_used_pages,
- zs_get_total_pages(zram->mem_pool));
+ zpool_get_total_size(zram->mem_pool) >> PAGE_SHIFT);
}
up_read(&zram->init_lock);
@@ -1020,7 +1023,7 @@ static ssize_t compact_store(struct device *dev,
return -EINVAL;
}
- zs_compact(zram->mem_pool);
+ zpool_compact(zram->mem_pool);
up_read(&zram->init_lock);
return len;
@@ -1048,17 +1051,14 @@ static ssize_t mm_stat_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct zram *zram = dev_to_zram(dev);
- struct zs_pool_stats pool_stats;
u64 orig_size, mem_used = 0;
- long max_used;
+ long max_used, num_compacted = 0;
ssize_t ret;
- memset(&pool_stats, 0x00, sizeof(struct zs_pool_stats));
-
down_read(&zram->init_lock);
if (init_done(zram)) {
- mem_used = zs_get_total_pages(zram->mem_pool);
- zs_pool_stats(zram->mem_pool, &pool_stats);
+ mem_used = zpool_get_total_size(zram->mem_pool);
+ num_compacted = zpool_get_num_compacted(zram->mem_pool);
}
orig_size = atomic64_read(&zram->stats.pages_stored);
@@ -1068,11 +1068,11 @@ static ssize_t mm_stat_show(struct device *dev,
"%8llu %8llu %8llu %8lu %8ld %8llu %8lu %8llu\n",
orig_size << PAGE_SHIFT,
(u64)atomic64_read(&zram->stats.compr_data_size),
- mem_used << PAGE_SHIFT,
+ mem_used,
zram->limit_pages << PAGE_SHIFT,
max_used << PAGE_SHIFT,
(u64)atomic64_read(&zram->stats.same_pages),
- pool_stats.pages_compacted,
+ num_compacted,
(u64)atomic64_read(&zram->stats.huge_pages));
up_read(&zram->init_lock);
@@ -1133,27 +1133,30 @@ static void zram_meta_free(struct zram *zram, u64 disksize)
for (index = 0; index < num_pages; index++)
zram_free_page(zram, index);
- zs_destroy_pool(zram->mem_pool);
+ zpool_destroy_pool(zram->mem_pool);
vfree(zram->table);
}
static bool zram_meta_alloc(struct zram *zram, u64 disksize)
{
size_t num_pages;
+ char *backend;
num_pages = disksize >> PAGE_SHIFT;
zram->table = vzalloc(array_size(num_pages, sizeof(*zram->table)));
if (!zram->table)
return false;
- zram->mem_pool = zs_create_pool(zram->disk->disk_name);
+ backend = strlen(backend_par_buf) ? backend_par_buf : "zsmalloc";
+ zram->mem_pool = zpool_create_pool(backend, zram->disk->disk_name,
+ GFP_NOIO, NULL);
if (!zram->mem_pool) {
vfree(zram->table);
return false;
}
if (!huge_class_size)
- huge_class_size = zs_huge_class_size(zram->mem_pool);
+ huge_class_size = zpool_huge_class_size(zram->mem_pool);
return true;
}
@@ -1197,7 +1200,7 @@ static void zram_free_page(struct zram *zram, size_t index)
if (!handle)
return;
- zs_free(zram->mem_pool, handle);
+ zpool_free(zram->mem_pool, handle);
atomic64_sub(zram_get_obj_size(zram, index),
&zram->stats.compr_data_size);
@@ -1246,7 +1249,7 @@ static int __zram_bvec_read(struct zram *zram, struct page *page, u32 index,
size = zram_get_obj_size(zram, index);
- src = zs_map_object(zram->mem_pool, handle, ZS_MM_RO);
+ src = zpool_map_handle(zram->mem_pool, handle, ZPOOL_MM_RO);
if (size == PAGE_SIZE) {
dst = kmap_atomic(page);
memcpy(dst, src, PAGE_SIZE);
@@ -1260,7 +1263,7 @@ static int __zram_bvec_read(struct zram *zram, struct page *page, u32 index,
kunmap_atomic(dst);
zcomp_stream_put(zram->comp);
}
- zs_unmap_object(zram->mem_pool, handle);
+ zpool_unmap_handle(zram->mem_pool, handle);
zram_slot_unlock(zram, index);
/* Should NEVER happen. Return bio error if it does. */
@@ -1335,7 +1338,7 @@ static int __zram_bvec_write(struct zram *zram, struct bio_vec *bvec,
if (unlikely(ret)) {
zcomp_stream_put(zram->comp);
pr_err("Compression failed! err=%d\n", ret);
- zs_free(zram->mem_pool, handle);
+ zpool_free(zram->mem_pool, handle);
return ret;
}
@@ -1354,33 +1357,34 @@ static int __zram_bvec_write(struct zram *zram, struct bio_vec *bvec,
* if we have a 'non-null' handle here then we are coming
* from the slow path and handle has already been allocated.
*/
- if (!handle)
- handle = zs_malloc(zram->mem_pool, comp_len,
+ if (handle == 0)
+ ret = zpool_malloc(zram->mem_pool, comp_len,
__GFP_KSWAPD_RECLAIM |
__GFP_NOWARN |
__GFP_HIGHMEM |
- __GFP_MOVABLE);
- if (!handle) {
+ __GFP_MOVABLE,
+ &handle);
+ if (ret) {
zcomp_stream_put(zram->comp);
atomic64_inc(&zram->stats.writestall);
- handle = zs_malloc(zram->mem_pool, comp_len,
- GFP_NOIO | __GFP_HIGHMEM |
- __GFP_MOVABLE);
- if (handle)
+ ret = zpool_malloc(zram->mem_pool, comp_len,
+ GFP_NOIO | __GFP_HIGHMEM | __GFP_MOVABLE,
+ &handle);
+ if (ret == 0)
goto compress_again;
return -ENOMEM;
}
- alloced_pages = zs_get_total_pages(zram->mem_pool);
+ alloced_pages = zpool_get_total_size(zram->mem_pool) >> PAGE_SHIFT;
update_used_max(zram, alloced_pages);
if (zram->limit_pages && alloced_pages > zram->limit_pages) {
zcomp_stream_put(zram->comp);
- zs_free(zram->mem_pool, handle);
+ zpool_free(zram->mem_pool, handle);
return -ENOMEM;
}
- dst = zs_map_object(zram->mem_pool, handle, ZS_MM_WO);
+ dst = zpool_map_handle(zram->mem_pool, handle, ZPOOL_MM_WO);
src = zstrm->buffer;
if (comp_len == PAGE_SIZE)
@@ -1390,7 +1394,7 @@ static int __zram_bvec_write(struct zram *zram, struct bio_vec *bvec,
kunmap_atomic(src);
zcomp_stream_put(zram->comp);
- zs_unmap_object(zram->mem_pool, handle);
+ zpool_unmap_handle(zram->mem_pool, handle);
atomic64_add(comp_len, &zram->stats.compr_data_size);
out:
/*
@@ -2136,6 +2140,8 @@ module_exit(zram_exit);
module_param(num_devices, uint, 0);
MODULE_PARM_DESC(num_devices, "Number of pre-created zram devices");
+module_param_string(backend, backend_par_buf, BACKEND_PAR_BUF_SIZE, S_IRUGO);
+MODULE_PARM_DESC(backend, "Compression storage (backend) name");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_AUTHOR("Nitin Gupta <ngupta@xxxxxxxxxx>");
diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
index f2fd46daa760..f4f51c6489ba 100644
--- a/drivers/block/zram/zram_drv.h
+++ b/drivers/block/zram/zram_drv.h
@@ -16,7 +16,7 @@
#define _ZRAM_DRV_H_
#include <linux/rwsem.h>
-#include <linux/zsmalloc.h>
+#include <linux/zpool.h>
#include <linux/crypto.h>
#include "zcomp.h"
@@ -91,7 +91,7 @@ struct zram_stats {
struct zram {
struct zram_table_entry *table;
- struct zs_pool *mem_pool;
+ struct zpool *mem_pool;
struct zcomp *comp;
struct gendisk *disk;
/* Prevent concurrent execution of device init */
--
2.20.1