+ zram-move-bd_stat-to-writeback-section.patch added to mm-new branch

+ zram-move-bd_stat-to-writeback-section.patch added to mm-new branch

[Andrew Morton]

The patch titled
     Subject: zram: move bd_stat to writeback section
has been added to the -mm mm-new branch.  Its filename is
     zram-move-bd_stat-to-writeback-section.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/zram-move-bd_stat-to-writeback-section.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
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fixup patches in mm-new.

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------------------------------------------------------
From: Sergey Senozhatsky <senozhatsky@chromium.org>
Subject: zram: move bd_stat to writeback section
Date: Mon, 1 Dec 2025 18:47:51 +0900

Move bd_stat function and attribute declaration to
existing CONFIG_WRITEBACK ifdef-sections.

Link: https://lkml.kernel.org/r/20251201094754.4149975-5-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Brian Geffon <bgeffon@google.com>
Cc: David Stevens <stevensd@google.com>
Cc: Minchan Kim <minchan@google.com>
Cc: Richard Chang <richardycc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/block/zram/zram_drv.c |   48 ++++++++++++++------------------
 1 file changed, 21 insertions(+), 27 deletions(-)

--- a/drivers/block/zram/zram_drv.c~zram-move-bd_stat-to-writeback-section
+++ a/drivers/block/zram/zram_drv.c
@@ -539,6 +539,24 @@ struct zram_rb_req {
 	u32 index;
 };
 
+#define FOUR_K(x) ((x) * (1 << (PAGE_SHIFT - 12)))
+static ssize_t bd_stat_show(struct device *dev, struct device_attribute *attr,
+			    char *buf)
+{
+	struct zram *zram = dev_to_zram(dev);
+	ssize_t ret;
+
+	down_read(&zram->init_lock);
+	ret = sysfs_emit(buf,
+			 "%8llu %8llu %8llu\n",
+			 FOUR_K((u64)atomic64_read(&zram->stats.bd_count)),
+			 FOUR_K((u64)atomic64_read(&zram->stats.bd_reads)),
+			 FOUR_K((u64)atomic64_read(&zram->stats.bd_writes)));
+	up_read(&zram->init_lock);
+
+	return ret;
+}
+
 static ssize_t writeback_compressed_store(struct device *dev,
 					  struct device_attribute *attr,
 					  const char *buf, size_t len)
@@ -1976,28 +1994,8 @@ static ssize_t mm_stat_show(struct devic
 	return ret;
 }
 
-#ifdef CONFIG_ZRAM_WRITEBACK
-#define FOUR_K(x) ((x) * (1 << (PAGE_SHIFT - 12)))
-static ssize_t bd_stat_show(struct device *dev,
-		struct device_attribute *attr, char *buf)
-{
-	struct zram *zram = dev_to_zram(dev);
-	ssize_t ret;
-
-	down_read(&zram->init_lock);
-	ret = sysfs_emit(buf,
-			"%8llu %8llu %8llu\n",
-			FOUR_K((u64)atomic64_read(&zram->stats.bd_count)),
-			FOUR_K((u64)atomic64_read(&zram->stats.bd_reads)),
-			FOUR_K((u64)atomic64_read(&zram->stats.bd_writes)));
-	up_read(&zram->init_lock);
-
-	return ret;
-}
-#endif
-
 static ssize_t debug_stat_show(struct device *dev,
-		struct device_attribute *attr, char *buf)
+			       struct device_attribute *attr, char *buf)
 {
 	int version = 1;
 	struct zram *zram = dev_to_zram(dev);
@@ -2015,9 +2013,6 @@ static ssize_t debug_stat_show(struct de
 
 static DEVICE_ATTR_RO(io_stat);
 static DEVICE_ATTR_RO(mm_stat);
-#ifdef CONFIG_ZRAM_WRITEBACK
-static DEVICE_ATTR_RO(bd_stat);
-#endif
 static DEVICE_ATTR_RO(debug_stat);
 
 static void zram_meta_free(struct zram *zram, u64 disksize)
@@ -3079,6 +3074,7 @@ static DEVICE_ATTR_WO(mem_used_max);
 static DEVICE_ATTR_WO(idle);
 static DEVICE_ATTR_RW(comp_algorithm);
 #ifdef CONFIG_ZRAM_WRITEBACK
+static DEVICE_ATTR_RO(bd_stat);
 static DEVICE_ATTR_RW(backing_dev);
 static DEVICE_ATTR_WO(writeback);
 static DEVICE_ATTR_RW(writeback_limit);
@@ -3102,6 +3098,7 @@ static struct attribute *zram_disk_attrs
 	&dev_attr_idle.attr,
 	&dev_attr_comp_algorithm.attr,
 #ifdef CONFIG_ZRAM_WRITEBACK
+	&dev_attr_bd_stat.attr,
 	&dev_attr_backing_dev.attr,
 	&dev_attr_writeback.attr,
 	&dev_attr_writeback_limit.attr,
@@ -3111,9 +3108,6 @@ static struct attribute *zram_disk_attrs
 #endif
 	&dev_attr_io_stat.attr,
 	&dev_attr_mm_stat.attr,
-#ifdef CONFIG_ZRAM_WRITEBACK
-	&dev_attr_bd_stat.attr,
-#endif
 	&dev_attr_debug_stat.attr,
 #ifdef CONFIG_ZRAM_MULTI_COMP
 	&dev_attr_recomp_algorithm.attr,
_

Patches currently in -mm which might be from senozhatsky@chromium.org are

zram-document-writeback_batch_size.patch
zram-move-bd_stat-to-writeback-section.patch
zram-rename-zram_free_page.patch
zram-switch-to-guard-for-init_lock.patch
zram-consolidate-device-attr-declarations.patch