+ zram-reset-writeback-state-in-zram_reset_device.patch added to mm-nonmm-unstable branch

+ zram-reset-writeback-state-in-zram_reset_device.patch added to mm-nonmm-unstable branch

[Andrew Morton]

The patch titled
     Subject: zram: reset writeback state in zram_reset_device()
has been added to the -mm mm-nonmm-unstable branch.  Its filename is
     zram-reset-writeback-state-in-zram_reset_device.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/zram-reset-writeback-state-in-zram_reset_device.patch

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

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via various
branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there most days

------------------------------------------------------
From: Sergey Senozhatsky <senozhatsky@chromium.org>
Subject: zram: reset writeback state in zram_reset_device()
Date: Sun, 25 Oct 2026 11:18:19 +0900

Reset all writeback state to its initial defaults on device reset.
We used to keep writeback related data in zram->stats, which
zram_reset_device() clears, but commit 1d69a3f8ae77 ("zram: idle
writeback fixes and cleanup") moved it (along with the newly added
wb_limit_enable) to struct zram, after which neither of them was
reset anymore.  wb_batch_size and compressed_wb, which were added
later, are not reset either.

The patch is more about just being pedantic.

Link: https://lore.kernel.org/20261025021839.1542805-4-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Brian Geffon <bgeffon@google.com>
Reviewed-by: Barry Song <baohua@kernel.org>
Cc: Bo Zhang <zhangbo0325@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Richard Chang <richardycc@google.com>
Cc: Bo Zhang <zhangbo56@xiaomi.com>
Cc: Hillf Danton <hdanton@sina.com>
---

 drivers/block/zram/zram_drv.c |    7 +++++++
 1 file changed, 7 insertions(+)

--- a/drivers/block/zram/zram_drv.c~zram-reset-writeback-state-in-zram_reset_device
+++ a/drivers/block/zram/zram_drv.c
@@ -694,6 +694,7 @@ static void reset_bdev(struct zram *zram
 	zram->disk->fops = &zram_devops;
 	kvfree(zram->bitmap);
 	zram->bitmap = NULL;
+	zram->nr_pages = 0;
 }
 
 static ssize_t backing_dev_show(struct device *dev,
@@ -2881,6 +2882,12 @@ static void zram_reset_device(struct zra
 	zram_destroy_comps(zram);
 	memset(&zram->stats, 0, sizeof(zram->stats));
 	reset_bdev(zram);
+#ifdef CONFIG_ZRAM_WRITEBACK
+	zram->wb_limit_enable = false;
+	zram->bd_wb_limit = 0;
+	zram->wb_batch_size = 32;
+	zram->compressed_wb = false;
+#endif
 }
 
 static ssize_t disksize_store(struct device *dev, struct device_attribute *attr,
_

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

zram-prefix-backends-printk-s.patch
zram-remove-debugfs-entry-on-init-failure.patch
zram-reset-writeback-state-in-zram_reset_device.patch
zram-move-mark_slot_accessed-under-existing-slot-lock-sections.patch
zram-remove-stale-warn_on-from-zram_read_page.patch
zram-zstd-do-not-allocate-empty-c-d-dictionaries.patch
zram-lz4hc-pre-initialize-dictionary-stream-in-setup_params.patch
zram-lz4-use-lz4_decompress_safe_usingdict.patch
zram-lz4hc-use-lz4_decompress_safe_usingdict.patch
zram-zstd-do-not-use-kvzalloc-for-zstd-allocations.patch
zram-split-zcomp-into-separate-r-w-streams.patch
zram-introduce-shared-decompression-streams.patch
zram-allocate-bounce-buffer-for-spanning-objects.patch
zram-borrow-idle-decompression-streams-in-exclusive-mode.patch
zram-use-a-singleton-compression-context-for-recompression.patch