+ zram-remove-stale-warn_on-from-zram_read_page.patch added to mm-nonmm-unstable branch

+ zram-remove-stale-warn_on-from-zram_read_page.patch added to mm-nonmm-unstable branch

[Andrew Morton]

The patch titled
     Subject: zram: remove stale WARN_ON() from zram_read_page()
has been added to the -mm mm-nonmm-unstable branch.  Its filename is
     zram-remove-stale-warn_on-from-zram_read_page.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/zram-remove-stale-warn_on-from-zram_read_page.patch

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

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------------------------------------------------------
From: Sergey Senozhatsky <senozhatsky@chromium.org>
Subject: zram: remove stale WARN_ON() from zram_read_page()
Date: Sun, 25 Oct 2026 11:18:21 +0900

The zram_read_page() WARN_ON() is not accurate anymore, because, in
theory, async read from bdev can return -EIO or -ENOMEM.  We report
errors to upper layers via bi_status, so upper layers printk errors.

Link: https://lore.kernel.org/20261025021839.1542805-6-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Brian Geffon <bgeffon@google.com>
Cc: 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 |    4 ----
 1 file changed, 4 deletions(-)

--- a/drivers/block/zram/zram_drv.c~zram-remove-stale-warn_on-from-zram_read_page
+++ a/drivers/block/zram/zram_drv.c
@@ -2204,10 +2204,6 @@ static int zram_read_page(struct zram *z
 		ret = read_from_bdev(zram, page, index, blk_idx, parent);
 	}
 
-	/* Should NEVER happen. Return bio error if it does. */
-	if (WARN_ON(ret < 0))
-		pr_err("Decompression failed! err=%d, page=%lu\n", ret, index);
-
 	return ret;
 }
 
_

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