zram: introduce zram data accessor

With element, sometime I got confused handle and element access.  It
might be my bad but I think it's time to introduce accessor to prevent
future idiot like me.  This patch is just clean-up patch so it shouldn't
change any behavior.

Link: http://lkml.kernel.org/r/1492052365-16169-6-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 22 insertions, 11 deletions

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index c674d23539b1..61b0f8374222 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -57,6 +57,16 @@ static inline struct zram *dev_to_zram(struct device *dev)
         return (struct zram *)dev_to_disk(dev)->private_data;
 }
 
+static unsigned long zram_get_handle(struct zram *zram, u32 index)
+{
+        return zram->table[index].handle;
+}
+
+static void zram_set_handle(struct zram *zram, u32 index, unsigned long handle)
+{
+        zram->table[index].handle = handle;
+}
+
 /* flag operations require table entry bit_spin_lock() being held */
 static int zram_test_flag(struct zram *zram, u32 index,
                         enum zram_pageflags flag)
@@ -82,9 +92,9 @@ static inline void zram_set_element(struct zram *zram, u32 index,
         zram->table[index].element = element;
 }
 
-static inline void zram_clear_element(struct zram *zram, u32 index)
+static unsigned long zram_get_element(struct zram *zram, u32 index)
 {
-        zram->table[index].element = 0;
+        return zram->table[index].element;
 }
 
 static size_t zram_get_obj_size(struct zram *zram, u32 index)
@@ -425,13 +435,14 @@ static bool zram_same_page_read(struct zram *zram, u32 index,
                                 unsigned int offset, unsigned int len)
 {
         zram_slot_lock(zram, index);
-        if (unlikely(!zram->table[index].handle) ||
-                        zram_test_flag(zram, index, ZRAM_SAME)) {
+        if (unlikely(!zram_get_handle(zram, index) ||
+                        zram_test_flag(zram, index, ZRAM_SAME))) {
                 void *mem;
 
                 zram_slot_unlock(zram, index);
                 mem = kmap_atomic(page);
-                zram_fill_page(mem + offset, len, zram->table[index].element);
+                zram_fill_page(mem + offset, len,
+                                        zram_get_element(zram, index));
                 kunmap_atomic(mem);
                 return true;
         }
@@ -470,7 +481,7 @@ static void zram_meta_free(struct zram *zram, u64 disksize)
 
         /* Free all pages that are still in this zram device */
         for (index = 0; index < num_pages; index++) {
-                unsigned long handle = zram->table[index].handle;
+                unsigned long handle = zram_get_handle(zram, index);
                 /*
                  * No memory is allocated for same element filled pages.
                  * Simply clear same page flag.
@@ -510,7 +521,7 @@ static bool zram_meta_alloc(struct zram *zram, u64 disksize)
  */
 static void zram_free_page(struct zram *zram, size_t index)
 {
-        unsigned long handle = zram->table[index].handle;
+        unsigned long handle = zram_get_handle(zram, index);
 
         /*
          * No memory is allocated for same element filled pages.
@@ -518,7 +529,7 @@ static void zram_free_page(struct zram *zram, size_t index)
          */
         if (zram_test_flag(zram, index, ZRAM_SAME)) {
                 zram_clear_flag(zram, index, ZRAM_SAME);
-                zram_clear_element(zram, index);
+                zram_set_element(zram, index, 0);
                 atomic64_dec(&zram->stats.same_pages);
                 return;
         }
@@ -532,7 +543,7 @@ static void zram_free_page(struct zram *zram, size_t index)
                         &zram->stats.compr_data_size);
         atomic64_dec(&zram->stats.pages_stored);
 
-        zram->table[index].handle = 0;
+        zram_set_handle(zram, index, 0);
         zram_set_obj_size(zram, index, 0);
 }
 
@@ -547,7 +558,7 @@ static int zram_decompress_page(struct zram *zram, struct page *page, u32 index)
                 return 0;
 
         zram_slot_lock(zram, index);
-        handle = zram->table[index].handle;
+        handle = zram_get_handle(zram, index);
         size = zram_get_obj_size(zram, index);
 
         src = zs_map_object(zram->mem_pool, handle, ZS_MM_RO);
@@ -713,7 +724,7 @@ static int __zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index)
          */
         zram_slot_lock(zram, index);
         zram_free_page(zram, index);
-        zram->table[index].handle = handle;
+        zram_set_handle(zram, index, handle);
         zram_set_obj_size(zram, index, comp_len);
         zram_slot_unlock(zram, index);