[PATCH] zram: add zpool support

From: Geliang Tang
Date: Wed Jun 08 2016 - 05:39:42 EST


This patch adds zpool support for zram, it will allow us to use both
the zpool api and directly zsmalloc api in zram.

Signed-off-by: Geliang Tang <geliangtang@xxxxxxxxx>
---
drivers/block/zram/zram_drv.c | 97 +++++++++++++++++++++++++++++++++++++++++++
drivers/block/zram/zram_drv.h | 5 +++
2 files changed, 102 insertions(+)

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 9e2a83c..1f90bd0 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -43,6 +43,11 @@ static const char *default_compressor = "lzo";
/* Module params (documentation at end) */
static unsigned int num_devices = 1;

+#ifdef CONFIG_ZPOOL
+/* Compressed storage zpool to use */
+#define ZRAM_ZPOOL_DEFAULT "zsmalloc"
+#endif
+
static inline void deprecated_attr_warn(const char *name)
{
pr_warn_once("%d (%s) Attribute %s (and others) will be removed. %s\n",
@@ -228,7 +233,11 @@ static ssize_t mem_used_total_show(struct device *dev,
down_read(&zram->init_lock);
if (init_done(zram)) {
struct zram_meta *meta = zram->meta;
+#ifdef CONFIG_ZPOOL
+ val = zpool_get_total_size(meta->mem_pool) >> PAGE_SHIFT;
+#else
val = zs_get_total_pages(meta->mem_pool);
+#endif
}
up_read(&zram->init_lock);

@@ -296,8 +305,14 @@ static ssize_t mem_used_max_store(struct device *dev,
down_read(&zram->init_lock);
if (init_done(zram)) {
struct zram_meta *meta = zram->meta;
+#ifdef CONFIG_ZPOOL
+ atomic_long_set(&zram->stats.max_used_pages,
+ zpool_get_total_size(meta->mem_pool)
+ >> PAGE_SHIFT);
+#else
atomic_long_set(&zram->stats.max_used_pages,
zs_get_total_pages(meta->mem_pool));
+#endif
}
up_read(&zram->init_lock);

@@ -366,6 +381,18 @@ static ssize_t comp_algorithm_store(struct device *dev,
return len;
}

+#ifdef CONFIG_ZPOOL
+static void zpool_compact(void *pool)
+{
+ zs_compact(pool);
+}
+
+static void zpool_stats(void *pool, struct zs_pool_stats *stats)
+{
+ zs_pool_stats(pool, stats);
+}
+#endif
+
static ssize_t compact_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t len)
{
@@ -379,7 +406,11 @@ static ssize_t compact_store(struct device *dev,
}

meta = zram->meta;
+#ifdef CONFIG_ZPOOL
+ zpool_compact(meta->mem_pool);
+#else
zs_compact(meta->mem_pool);
+#endif
up_read(&zram->init_lock);

return len;
@@ -416,8 +447,14 @@ static ssize_t mm_stat_show(struct device *dev,

down_read(&zram->init_lock);
if (init_done(zram)) {
+#ifdef CONFIG_ZPOOL
+ mem_used = zpool_get_total_size(zram->meta->mem_pool)
+ >> PAGE_SHIFT;
+ zpool_stats(zram->meta->mem_pool, &pool_stats);
+#else
mem_used = zs_get_total_pages(zram->meta->mem_pool);
zs_pool_stats(zram->meta->mem_pool, &pool_stats);
+#endif
}

orig_size = atomic64_read(&zram->stats.pages_stored);
@@ -490,10 +527,18 @@ static void zram_meta_free(struct zram_meta *meta, u64 disksize)
if (!handle)
continue;

+#ifdef CONFIG_ZPOOL
+ zpool_free(meta->mem_pool, handle);
+#else
zs_free(meta->mem_pool, handle);
+#endif
}

+#ifdef CONFIG_ZPOOL
+ zpool_destroy_pool(meta->mem_pool);
+#else
zs_destroy_pool(meta->mem_pool);
+#endif
vfree(meta->table);
kfree(meta);
}
@@ -513,7 +558,17 @@ static struct zram_meta *zram_meta_alloc(char *pool_name, u64 disksize)
goto out_error;
}

+#ifdef CONFIG_ZPOOL
+ if (!zpool_has_pool(ZRAM_ZPOOL_DEFAULT)) {
+ pr_err("zpool %s not available\n", ZRAM_ZPOOL_DEFAULT);
+ goto out_error;
+ }
+
+ meta->mem_pool = zpool_create_pool(ZRAM_ZPOOL_DEFAULT,
+ pool_name, 0, NULL);
+#else
meta->mem_pool = zs_create_pool(pool_name);
+#endif
if (!meta->mem_pool) {
pr_err("Error creating memory pool\n");
goto out_error;
@@ -549,7 +604,11 @@ static void zram_free_page(struct zram *zram, size_t index)
return;
}

+#ifdef CONFIG_ZPOOL
+ zpool_free(meta->mem_pool, handle);
+#else
zs_free(meta->mem_pool, handle);
+#endif

atomic64_sub(zram_get_obj_size(meta, index),
&zram->stats.compr_data_size);
@@ -577,7 +636,11 @@ static int zram_decompress_page(struct zram *zram, char *mem, u32 index)
return 0;
}

+#ifdef CONFIG_ZPOOL
+ cmem = zpool_map_handle(meta->mem_pool, handle, ZPOOL_MM_RO);
+#else
cmem = zs_map_object(meta->mem_pool, handle, ZS_MM_RO);
+#endif
if (size == PAGE_SIZE) {
copy_page(mem, cmem);
} else {
@@ -586,7 +649,11 @@ static int zram_decompress_page(struct zram *zram, char *mem, u32 index)
ret = zcomp_decompress(zstrm, cmem, size, mem);
zcomp_stream_put(zram->comp);
}
+#ifdef CONFIG_ZPOOL
+ zpool_unmap_handle(meta->mem_pool, handle);
+#else
zs_unmap_object(meta->mem_pool, handle);
+#endif
bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value);

/* Should NEVER happen. Return bio error if it does. */
@@ -735,20 +802,34 @@ compress_again:
* from the slow path and handle has already been allocated.
*/
if (!handle)
+#ifdef CONFIG_ZPOOL
+ ret = zpool_malloc(meta->mem_pool, clen,
+ __GFP_KSWAPD_RECLAIM |
+ __GFP_NOWARN |
+ __GFP_HIGHMEM |
+ __GFP_MOVABLE, &handle);
+#else
handle = zs_malloc(meta->mem_pool, clen,
__GFP_KSWAPD_RECLAIM |
__GFP_NOWARN |
__GFP_HIGHMEM |
__GFP_MOVABLE);
+#endif
if (!handle) {
zcomp_stream_put(zram->comp);
zstrm = NULL;

atomic64_inc(&zram->stats.writestall);

+#ifdef CONFIG_ZPOOL
+ ret = zpool_malloc(meta->mem_pool, clen,
+ GFP_NOIO | __GFP_HIGHMEM |
+ __GFP_MOVABLE, &handle);
+#else
handle = zs_malloc(meta->mem_pool, clen,
GFP_NOIO | __GFP_HIGHMEM |
__GFP_MOVABLE);
+#endif
if (handle)
goto compress_again;

@@ -758,16 +839,28 @@ compress_again:
goto out;
}

+#ifdef CONFIG_ZPOOL
+ alloced_pages = zpool_get_total_size(meta->mem_pool) >> PAGE_SHIFT;
+#else
alloced_pages = zs_get_total_pages(meta->mem_pool);
+#endif
update_used_max(zram, alloced_pages);

if (zram->limit_pages && alloced_pages > zram->limit_pages) {
+#ifdef CONFIG_ZPOOL
+ zpool_free(meta->mem_pool, handle);
+#else
zs_free(meta->mem_pool, handle);
+#endif
ret = -ENOMEM;
goto out;
}

+#ifdef CONFIG_ZPOOL
+ cmem = zpool_map_handle(meta->mem_pool, handle, ZPOOL_MM_WO);
+#else
cmem = zs_map_object(meta->mem_pool, handle, ZS_MM_WO);
+#endif

if ((clen == PAGE_SIZE) && !is_partial_io(bvec)) {
src = kmap_atomic(page);
@@ -779,7 +872,11 @@ compress_again:

zcomp_stream_put(zram->comp);
zstrm = NULL;
+#ifdef CONFIG_ZPOOL
+ zpool_unmap_handle(meta->mem_pool, handle);
+#else
zs_unmap_object(meta->mem_pool, handle);
+#endif

/*
* Free memory associated with this sector
diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
index 74fcf10..68f1222 100644
--- a/drivers/block/zram/zram_drv.h
+++ b/drivers/block/zram/zram_drv.h
@@ -17,6 +17,7 @@

#include <linux/rwsem.h>
#include <linux/zsmalloc.h>
+#include <linux/zpool.h>
#include <linux/crypto.h>

#include "zcomp.h"
@@ -91,7 +92,11 @@ struct zram_stats {

struct zram_meta {
struct zram_table_entry *table;
+#ifdef CONFIG_ZPOOL
+ struct zpool *mem_pool;
+#else
struct zs_pool *mem_pool;
+#endif
};

struct zram {
--
1.9.1