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: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/block/zram/Makefile b/drivers/block/zram/Makefile
index cb0f9ce..757c6a5 100644 (file)
--- a/drivers/block/zram/Makefile
+++ b/drivers/block/zram/Makefile
@@ -1,3 +1,3 @@
-zram-y :=      zram_drv.o
+zram-y :=      zcomp_lzo.o zcomp.o zram_drv.o
 
 obj-$(CONFIG_ZRAM)     +=      zram.o

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 76ba676..98823f9 100644 (file)
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -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,

diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
index 1d5b1f5..45e04f7 100644 (file)
--- a/drivers/block/zram/zram_drv.h
+++ b/drivers/block/zram/zram_drv.h
@@ -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;
        /*