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Date: Mon, 29 May 2017 09:50:48 +0900
From: Minchan Kim <minchan@...nel.org>
To: Andrew Morton <akpm@...ux-foundation.org>
CC: <linux-kernel@...r.kernel.org>, kernel-team <kernel-team@....com>,
Minchan Kim <minchan@...nel.org>,
Sergey Senozhatsky <sergey.senozhatsky@...il.com>
Subject: [PATCH] zram: clean up duplicated codes in __zram_bvec_write
__zram_bvec_write has some of duplicated logic for zram meta
data handling of same_page|dedup_page|compressed_page.
This patch aims to clean it up without behavior change.
Cc: Sergey Senozhatsky <sergey.senozhatsky@...il.com>
Signed-off-by: Minchan Kim <minchan@...nel.org>
---
drivers/block/zram/zram_drv.c | 70 +++++++++++++++++--------------------------
1 file changed, 27 insertions(+), 43 deletions(-)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 5f2a862..0557c15 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -500,30 +500,6 @@ 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 struct zram_entry *zram_entry_alloc(struct zram *zram,
unsigned int len, gfp_t flags)
{
@@ -790,28 +766,31 @@ static int zram_compress(struct zram *zram, struct zcomp_strm **zstrm,
static int __zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index)
{
int ret;
- struct zram_entry *entry;
- unsigned int comp_len;
- void *src, *dst;
+ struct zram_entry *uninitialized_var(entry);
+ unsigned int uninitialized_var(comp_len);
+ void *src, *dst, *mem;
struct zcomp_strm *zstrm;
struct page *page = bvec->bv_page;
u32 checksum;
+ enum zram_pageflags flags = 0;
+ unsigned long uninitialized_var(element);
- 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. */
+ flags = ZRAM_SAME;
+ atomic64_inc(&zram->stats.same_pages);
+ goto out;
+ }
+ kunmap_atomic(mem);
entry = zram_dedup_find(zram, page, &checksum);
if (entry) {
comp_len = entry->len;
- zram_slot_lock(zram, index);
- zram_free_page(zram, index);
- zram_set_flag(zram, index, ZRAM_DUP);
- zram_set_entry(zram, index, entry);
- zram_set_obj_size(zram, index, comp_len);
- zram_slot_unlock(zram, index);
+ flags = ZRAM_DUP;
atomic64_add(comp_len, &zram->stats.dup_data_size);
- atomic64_inc(&zram->stats.pages_stored);
- return 0;
+ goto out;
}
zstrm = zcomp_stream_get(zram->comp);
@@ -835,19 +814,24 @@ static int __zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index)
zs_unmap_object(zram->mem_pool, zram_entry_handle(zram, entry));
zram_dedup_insert(zram, entry, checksum);
+out:
+ zram_slot_lock(zram, index);
/*
* Free memory associated with this sector
* before overwriting unused sectors.
*/
- zram_slot_lock(zram, index);
zram_free_page(zram, index);
- zram_set_entry(zram, index, entry);
- zram_set_obj_size(zram, index, comp_len);
+ if (flags)
+ zram_set_flag(zram, index, flags);
+ if (flags != ZRAM_SAME) {
+ zram_set_obj_size(zram, index, comp_len);
+ zram_set_entry(zram, index, entry);
+ } else {
+ zram_set_element(zram, index, element);
+ }
zram_slot_unlock(zram, index);
-
- /* Update stats */
- atomic64_add(comp_len, &zram->stats.compr_data_size);
atomic64_inc(&zram->stats.pages_stored);
+
return 0;
}
--
2.7.4
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