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path: root/drivers/block/zram/zram_drv.c
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Diffstat (limited to 'drivers/block/zram/zram_drv.c')
-rw-r--r--drivers/block/zram/zram_drv.c56
1 files changed, 23 insertions, 33 deletions
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 3b1b6340ba13..f1a94f449c6d 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -453,30 +453,6 @@ static bool zram_same_page_read(struct zram *zram, u32 index,
return false;
}
-static bool zram_same_page_write(struct zram *zram, u32 index,
- struct page *page)
-{
- unsigned long element;
- void *mem = kmap_atomic(page);
-
- if (page_same_filled(mem, &element)) {
- kunmap_atomic(mem);
- /* Free memory associated with this sector now. */
- zram_slot_lock(zram, index);
- zram_free_page(zram, index);
- zram_set_flag(zram, index, ZRAM_SAME);
- zram_set_element(zram, index, element);
- zram_slot_unlock(zram, index);
-
- atomic64_inc(&zram->stats.same_pages);
- atomic64_inc(&zram->stats.pages_stored);
- return true;
- }
- kunmap_atomic(mem);
-
- return false;
-}
-
static void zram_meta_free(struct zram *zram, u64 disksize)
{
size_t num_pages = disksize >> PAGE_SHIFT;
@@ -685,14 +661,23 @@ compress_again:
static int __zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index)
{
int ret;
- unsigned long handle;
- unsigned int comp_len;
- void *src, *dst;
+ unsigned long handle = 0;
+ unsigned int comp_len = 0;
+ void *src, *dst, *mem;
struct zcomp_strm *zstrm;
struct page *page = bvec->bv_page;
+ unsigned long element = 0;
+ enum zram_pageflags flags = 0;
- if (zram_same_page_write(zram, index, page))
- return 0;
+ mem = kmap_atomic(page);
+ if (page_same_filled(mem, &element)) {
+ kunmap_atomic(mem);
+ /* Free memory associated with this sector now */
+ atomic64_inc(&zram->stats.same_pages);
+ flags = ZRAM_SAME;
+ goto out;
+ }
+ kunmap_atomic(mem);
zstrm = zcomp_stream_get(zram->comp);
ret = zram_compress(zram, &zstrm, page, &handle, &comp_len);
@@ -712,19 +697,24 @@ static int __zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index)
zcomp_stream_put(zram->comp);
zs_unmap_object(zram->mem_pool, handle);
-
+ atomic64_add(comp_len, &zram->stats.compr_data_size);
+out:
/*
* Free memory associated with this sector
* before overwriting unused sectors.
*/
zram_slot_lock(zram, index);
zram_free_page(zram, index);
- zram_set_handle(zram, index, handle);
- zram_set_obj_size(zram, index, comp_len);
+ if (flags == ZRAM_SAME) {
+ zram_set_flag(zram, index, ZRAM_SAME);
+ zram_set_element(zram, index, element);
+ } else {
+ zram_set_handle(zram, index, handle);
+ zram_set_obj_size(zram, index, comp_len);
+ }
zram_slot_unlock(zram, index);
/* Update stats */
- atomic64_add(comp_len, &zram->stats.compr_data_size);
atomic64_inc(&zram->stats.pages_stored);
return 0;
}