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Commit b7ca232e authored by Sergey Senozhatsky's avatar Sergey Senozhatsky Committed by Linus Torvalds
Browse files

zram: use zcomp compressing backends 



Do not perform direct LZO compress/decompress calls, initialise
and use zcomp LZO backend (single compression stream) instead.

[akpm@linux-foundation.org: resolve conflicts with zram-delete-zram_init_device-fix.patch]
Signed-off-by: default avatarSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: default avatarMinchan Kim <minchan@kernel.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e7e1ef43

drivers/block/zram/Makefile

+1 −1
Original line number Diff line number Diff line 
zram-y	:=	zram_drv.o

zram-y	:=	zcomp_lzo.o zcomp.o zram_drv.o



obj-$(CONFIG_ZRAM)	+=	zram.o

drivers/block/zram/zram_drv.c

+31 −38
Original line number Diff line number Diff line
@@ -29,7 +29,6 @@ 
#include <linux/genhd.h>

#include <linux/highmem.h>

#include <linux/slab.h>

#include <linux/lzo.h>

#include <linux/string.h>

#include <linux/vmalloc.h>
@@ -38,6 +37,7 @@ 
/* Globals */

static int zram_major;

static struct zram *zram_devices;

static const char *default_compressor = "lzo";



/* Module params (documentation at end) */

static unsigned int num_devices = 1;
@@ -160,8 +160,6 @@ static inline int valid_io_request(struct zram *zram, struct bio *bio) 
static void zram_meta_free(struct zram_meta *meta)

{

	zs_destroy_pool(meta->mem_pool);

	kfree(meta->compress_workmem);

	free_pages((unsigned long)meta->compress_buffer, 1);

	vfree(meta->table);

	kfree(meta);

}
@@ -173,22 +171,11 @@ static struct zram_meta *zram_meta_alloc(u64 disksize) 
	if (!meta)

		goto out;



	meta->compress_workmem = kzalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL);

	if (!meta->compress_workmem)

		goto free_meta;



	meta->compress_buffer =

		(void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 1);

	if (!meta->compress_buffer) {

		pr_err("Error allocating compressor buffer space\n");

		goto free_workmem;

	}



	num_pages = disksize >> PAGE_SHIFT;

	meta->table = vzalloc(num_pages * sizeof(*meta->table));

	if (!meta->table) {

		pr_err("Error allocating zram address table\n");

		goto free_buffer;

		goto free_meta;

	}



	meta->mem_pool = zs_create_pool(GFP_NOIO | __GFP_HIGHMEM);
@@ -198,15 +185,10 @@ static struct zram_meta *zram_meta_alloc(u64 disksize) 
	}



	rwlock_init(&meta->tb_lock);

	mutex_init(&meta->buffer_lock);

	return meta;



free_table:

	vfree(meta->table);

free_buffer:

	free_pages((unsigned long)meta->compress_buffer, 1);

free_workmem:

	kfree(meta->compress_workmem);

free_meta:

	kfree(meta);

	meta = NULL;
@@ -280,8 +262,7 @@ static void zram_free_page(struct zram *zram, size_t index) 


static int zram_decompress_page(struct zram *zram, char *mem, u32 index)

{

	int ret = LZO_E_OK;

	size_t clen = PAGE_SIZE;

	int ret = 0;

	unsigned char *cmem;

	struct zram_meta *meta = zram->meta;

	unsigned long handle;
@@ -301,12 +282,12 @@ static int zram_decompress_page(struct zram *zram, char *mem, u32 index) 
	if (size == PAGE_SIZE)

		copy_page(mem, cmem);

	else

		ret = lzo1x_decompress_safe(cmem, size,	mem, &clen);

		ret = zcomp_decompress(zram->comp, cmem, size, mem);

	zs_unmap_object(meta->mem_pool, handle);

	read_unlock(&meta->tb_lock);



	/* Should NEVER happen. Return bio error if it does. */

	if (unlikely(ret != LZO_E_OK)) {

	if (unlikely(ret)) {

		pr_err("Decompression failed! err=%d, page=%u\n", ret, index);

		atomic64_inc(&zram->stats.failed_reads);

		return ret;
@@ -349,7 +330,7 @@ static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec, 


	ret = zram_decompress_page(zram, uncmem, index);

	/* Should NEVER happen. Return bio error if it does. */

	if (unlikely(ret != LZO_E_OK))

	if (unlikely(ret))

		goto out_cleanup;



	if (is_partial_io(bvec))
@@ -374,11 +355,10 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index, 
	struct page *page;

	unsigned char *user_mem, *cmem, *src, *uncmem = NULL;

	struct zram_meta *meta = zram->meta;

	struct zcomp_strm *zstrm;

	bool locked = false;



	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
@@ -394,7 +374,7 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index, 
			goto out;

	}



	mutex_lock(&meta->buffer_lock);

	zstrm = zcomp_strm_find(zram->comp);

	locked = true;

	user_mem = kmap_atomic(page);
@@ -420,22 +400,20 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index, 
		goto out;

	}



	ret = lzo1x_1_compress(uncmem, PAGE_SIZE, src, &clen,

			       meta->compress_workmem);

	ret = zcomp_compress(zram->comp, zstrm, uncmem, &clen);

	if (!is_partial_io(bvec)) {

		kunmap_atomic(user_mem);

		user_mem = NULL;

		uncmem = NULL;

	}



	if (unlikely(ret != LZO_E_OK)) {

	if (unlikely(ret)) {

		pr_err("Compression failed! err=%d\n", ret);

		goto out;

	}



	src = zstrm->buffer;

	if (unlikely(clen > max_zpage_size)) {

		clen = PAGE_SIZE;

		src = NULL;

		if (is_partial_io(bvec))

			src = uncmem;

	}
@@ -457,6 +435,8 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index, 
		memcpy(cmem, src, clen);

	}



	zcomp_strm_release(zram->comp, zstrm);

	locked = false;

	zs_unmap_object(meta->mem_pool, handle);



	/*
@@ -475,10 +455,9 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index, 
	atomic64_inc(&zram->stats.pages_stored);

out:

	if (locked)

		mutex_unlock(&meta->buffer_lock);

		zcomp_strm_release(zram->comp, zstrm);

	if (is_partial_io(bvec))

		kfree(uncmem);



	if (ret)

		atomic64_inc(&zram->stats.failed_writes);

	return ret;
@@ -522,6 +501,7 @@ static void zram_reset_device(struct zram *zram, bool reset_capacity) 
		zs_free(meta->mem_pool, handle);

	}



	zcomp_destroy(zram->comp);

	zram_meta_free(zram->meta);

	zram->meta = NULL;

	/* Reset stats */
@@ -539,6 +519,7 @@ static ssize_t disksize_store(struct device *dev, 
	u64 disksize;

	struct zram_meta *meta;

	struct zram *zram = dev_to_zram(dev);

	int err;



	disksize = memparse(buf, NULL);

	if (!disksize)
@@ -551,10 +532,17 @@ static ssize_t disksize_store(struct device *dev, 


	down_write(&zram->init_lock);

	if (init_done(zram)) {

		zram_meta_free(meta);

		up_write(&zram->init_lock);

		pr_info("Cannot change disksize for initialized device\n");

		return -EBUSY;

		err = -EBUSY;

		goto out_free_meta;

	}



	zram->comp = zcomp_create(default_compressor);

	if (!zram->comp) {

		pr_info("Cannot initialise %s compressing backend\n",

				default_compressor);

		err = -EINVAL;

		goto out_free_meta;

	}



	zram->meta = meta;
@@ -563,6 +551,11 @@ static ssize_t disksize_store(struct device *dev, 
	up_write(&zram->init_lock);



	return len;



out_free_meta:

	up_write(&zram->init_lock);

	zram_meta_free(meta);

	return err;

}



static ssize_t reset_store(struct device *dev,

drivers/block/zram/zram_drv.h

+4 −4
Original line number Diff line number Diff line
@@ -16,9 +16,10 @@ 
#define _ZRAM_DRV_H_



#include <linux/spinlock.h>

#include <linux/mutex.h>

#include <linux/zsmalloc.h>



#include "zcomp.h"



/*

 * Some arbitrary value. This is just to catch

 * invalid value for num_devices module parameter.
@@ -81,17 +82,16 @@ struct zram_stats { 


struct zram_meta {

	rwlock_t tb_lock;	/* protect table */

	void *compress_workmem;

	void *compress_buffer;

	struct table *table;

	struct zs_pool *mem_pool;

	struct mutex buffer_lock; /* protect compress buffers */

};



struct zram {

	struct zram_meta *meta;

	struct request_queue *queue;

	struct gendisk *disk;

	struct zcomp *comp;



	/* Prevent concurrent execution of device init, reset and R/W request */

	struct rw_semaphore init_lock;

	/*