Re: [PATCH] zram: clean up duplicated codes in __zram_bvec_write

[Sergey Senozhatsky]

On (05/29/17 09:50), Minchan Kim wrote:
> __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 
> Signed-off-by: Minchan Kim 

Reviewed-by: Sergey Senozhatsky 

-ss

Re: [PATCH] zram: clean up duplicated codes in __zram_bvec_write

[Sergey Senozhatsky]

On (05/29/17 09:50), Minchan Kim wrote:
> __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 
> Signed-off-by: Minchan Kim 

Reviewed-by: Sergey Senozhatsky 

-ss

[PATCH] zram: clean up duplicated codes in __zram_bvec_write

[Minchan Kim]

__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 
Signed-off-by: Minchan Kim 
---
 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, )) {
-   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(>stats.same_pages);
-   atomic64_inc(>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, )) {
+   kunmap_atomic(mem);
+   /* Free memory associated with this sector now. */
+   flags = ZRAM_SAME;
+   atomic64_inc(>stats.same_pages);
+   goto out;
+   }
+   kunmap_atomic(mem);
 
entry = zram_dedup_find(zram, page, );
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, >stats.dup_data_size);
-   atomic64_inc(>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, >stats.compr_data_size);
atomic64_inc(>stats.pages_stored);
+
return 0;
 }
 
-- 
2.7.4

[PATCH] zram: clean up duplicated codes in __zram_bvec_write

[Minchan Kim]

__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 
Signed-off-by: Minchan Kim 
---
 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, )) {
-   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(>stats.same_pages);
-   atomic64_inc(>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, )) {
+   kunmap_atomic(mem);
+   /* Free memory associated with this sector now. */
+   flags = ZRAM_SAME;
+   atomic64_inc(>stats.same_pages);
+   goto out;
+   }
+   kunmap_atomic(mem);
 
entry = zram_dedup_find(zram, page, );
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, >stats.dup_data_size);
-   atomic64_inc(>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, >stats.compr_data_size);
atomic64_inc(>stats.pages_stored);
+
return 0;
 }
 
-- 
2.7.4