From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	patches@lists.linux.dev,
	Sergey Senozhatsky <senozhatsky@chromium.org>,
	Minchan Kim <minchan@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH 6.12 1013/1102] zram: remove entry element member
Date: Thu, 17 Sep 2026 16:15:56 +0100
Message-ID: <20260917151606.182637368@linuxfoundation.org>
In-Reply-To: <20260917151539.408551884@linuxfoundation.org>
References: <20260917151539.408551884@linuxfoundation.org>
User-Agent: quilt/0.69
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

6.12-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Sergey Senozhatsky <senozhatsky@chromium.org>

[ Upstream commit b4444a849f1827c04df81a6f1ef26ddb6f072a94 ]

Element is in the same anon union as handle and hence holds the same
value, which makes code below sort of confusing

    handle = zram_get_handle()
    if (!handle)
	element = zram_get_element()

Element doesn't really simplify the code, let's just remove it.  We
already re-purpose handle to store the block id a written back page.

Link: https://lkml.kernel.org/r/20241218063513.297475-3-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Stable-dep-of: 894913e2d35c ("zram: fix out-of-bounds access in writeback_store()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/block/zram/zram_drv.c |   23 +++++------------------
 drivers/block/zram/zram_drv.h |    5 +----
 2 files changed, 6 insertions(+), 22 deletions(-)

--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -112,17 +112,6 @@ static void zram_clear_flag(struct zram
 	zram->table[index].flags &= ~BIT(flag);
 }
 
-static inline void zram_set_element(struct zram *zram, u32 index,
-			unsigned long element)
-{
-	zram->table[index].element = element;
-}
-
-static unsigned long zram_get_element(struct zram *zram, u32 index)
-{
-	return zram->table[index].element;
-}
-
 static size_t zram_get_obj_size(struct zram *zram, u32 index)
 {
 	return zram->table[index].flags & (BIT(ZRAM_FLAG_SHIFT) - 1);
@@ -762,7 +751,7 @@ static ssize_t writeback_store(struct de
 		zram_free_page(zram, index);
 		zram_clear_flag(zram, index, ZRAM_UNDER_WB);
 		zram_set_flag(zram, index, ZRAM_WB);
-		zram_set_element(zram, index, blk_idx);
+		zram_set_handle(zram, index, blk_idx);
 		blk_idx = 0;
 		atomic64_inc(&zram->stats.pages_stored);
 		spin_lock(&zram->wb_limit_lock);
@@ -1390,7 +1379,7 @@ static void zram_free_page(struct zram *
 
 	if (zram_test_flag(zram, index, ZRAM_WB)) {
 		zram_clear_flag(zram, index, ZRAM_WB);
-		free_block_bdev(zram, zram_get_element(zram, index));
+		free_block_bdev(zram, zram_get_handle(zram, index));
 		goto out;
 	}
 
@@ -1436,12 +1425,10 @@ static int zram_read_from_zspool(struct
 
 	handle = zram_get_handle(zram, index);
 	if (!handle || zram_test_flag(zram, index, ZRAM_SAME)) {
-		unsigned long value;
 		void *mem;
 
-		value = handle ? zram_get_element(zram, index) : 0;
 		mem = kmap_local_page(page);
-		zram_fill_page(mem, PAGE_SIZE, value);
+		zram_fill_page(mem, PAGE_SIZE, handle);
 		kunmap_local(mem);
 		return 0;
 	}
@@ -1487,7 +1474,7 @@ static int zram_read_page(struct zram *z
 		 */
 		zram_slot_unlock(zram, index);
 
-		ret = read_from_bdev(zram, page, zram_get_element(zram, index),
+		ret = read_from_bdev(zram, page, zram_get_handle(zram, index),
 				     parent);
 	}
 
@@ -1639,7 +1626,7 @@ out:
 
 	if (flags) {
 		zram_set_flag(zram, index, flags);
-		zram_set_element(zram, index, element);
+		zram_set_handle(zram, index, element);
 	}  else {
 		zram_set_handle(zram, index, handle);
 		zram_set_obj_size(zram, index, comp_len);
--- a/drivers/block/zram/zram_drv.h
+++ b/drivers/block/zram/zram_drv.h
@@ -62,10 +62,7 @@ enum zram_pageflags {
 
 /* Allocated for each disk page */
 struct zram_table_entry {
-	union {
-		unsigned long handle;
-		unsigned long element;
-	};
+	unsigned long handle;
 	unsigned int flags;
 	spinlock_t lock;
 #ifdef CONFIG_ZRAM_TRACK_ENTRY_ACTIME