From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 45C5137E5D1; Sat, 12 Sep 2026 12:38:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789216683; cv=none; b=ilGNp8QEkuxeFLQf+0R9K6awyK2PCVsu3SKAxDd9ZHgxTJFUrewRgR4wbu0qHJVaGpgqOTX4oN+DSQX5wwbX3onLVOI6PpskDXKatrw4+vbhCCwckyLxJiMuJWwUFihWLhnpBJ4/fZXkXJFKj5WmPQ1e79zAuw2VMZpR0Hy3irM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789216683; c=relaxed/simple; bh=TnwdOicVCEr/Jf5N9qSvTXYAo2U32zOruFRrnIVPcn0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=MTDdhwEpeSB4SymYF5jmpAJnQ7Ia1l+6kPj7J8ZK41IvKowvPe5ByfRlgJMWyvSPnEaJ++TIHSSfnG16ak8ZJENb53q6wFxXXdpt828gDbxB44V1VU7ECXxk7GfFIY0j7eQtP9AVoPbMQPOJmXkAR+pjYQmLgXqUrEN9lt4C+cg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=C9xAIZNI; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="C9xAIZNI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3D5901F000FF; Sat, 12 Sep 2026 12:38:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789216682; bh=3S87onBEUvwK3H12CJSFqI2NgJbDqZsbSYukTRDzXtI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=C9xAIZNIwkqxDPgWcLr7zcaTiU11QCHN/l8DVPcGg2cpJseXbNRTbwsDwuLLFuVjC 2qSJzfakqRH3rEdu6riCgBbswzvneyxI6kHC03RicKWjzhCgd9VFaRFIAF8QZHqa0f G4D1/uknoAVsTe1MCEt9muKlWtZLvEXdEiuG7eoI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Abd-Alrhman Masalkhi , Yu Kuai , Sasha Levin Subject: [PATCH 6.12 0784/1376] md: skip redundant raid_disks update when value is unchanged Date: Sat, 12 Sep 2026 08:53:30 +0200 Message-ID: <20260912065625.010629432@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065607.535295758@linuxfoundation.org> References: <20260912065607.535295758@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Abd-Alrhman Masalkhi [ Upstream commit abaf4783822851678632e5cea98aa5aead99852f ] Calling update_raid_disks() with the same value as the current one can trigger unnecessary work. For example, RAID1 will reallocate resources such as the mempool for r1bio. Signed-off-by: Abd-Alrhman Masalkhi Link: https://patch.msgid.link/20260428130524.448063-1-abd.masalkhi@gmail.com Signed-off-by: Yu Kuai Stable-dep-of: bace2010dd7a ("md: scope memalloc_noio to allocation critical sections") Signed-off-by: Sasha Levin --- drivers/md/md.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 47b5415cd5a3b..27d8b973c89b1 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -4196,9 +4196,10 @@ raid_disks_store(struct mddev *mddev, const char *buf, size_t len) err = mddev_suspend_and_lock(mddev); if (err) return err; - if (mddev->pers) - err = update_raid_disks(mddev, n); - else if (mddev->reshape_position != MaxSector) { + if (mddev->pers) { + if (n != mddev->raid_disks) + err = update_raid_disks(mddev, n); + } else if (mddev->reshape_position != MaxSector) { struct md_rdev *rdev; int olddisks = mddev->raid_disks - mddev->delta_disks; -- 2.53.0