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 EA3A2288B2; Sat, 12 Sep 2026 10:28:10 +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=1789208892; cv=none; b=Ivb8Ts+5eF1KHjrNEGODAmrIX0UqS0d5cQf6H1DMYmlTDK/JjZsDwiRImtQzp/jfMS8Ab2nB4nS6E5solQ2xrUEqkp7FNP+89DWAV5P9fW/C/gcNk0KsBWjSKP7ABu4mb45uWj8IqbYLr+7IJpJIZgS4iEVl1MCAMcL/PG+zD3U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789208892; c=relaxed/simple; bh=ngFumisuZDfm1firR8Xnrdxd3GQNYyjSJv85kwCGngk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jmZPIKgOEpqUCv7QrxIUTBguLBTSTkTnwYkLI+JXUOprYDe58/jd2c+uXHvZt7++O4A/7kHkjOUPZTEWVKBUWk3ly5ly3Asv6IXkDPsI3wv3KaLQfZRwTKDiyKUs1AMP2mI5wygD4qx+SGRYCzoWdhDYciOdSb3Ko5fB4or74Tg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=eAtp6ySU; 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="eAtp6ySU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F26591F000FF; Sat, 12 Sep 2026 10:28:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789208890; bh=y9SJguJ3AGFuB/gqhh6puenS9f5Hb+0shGzCcs30XvY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=eAtp6ySUoWuhRhl0Crkfm3anAsgxAK2y1TZipJvDdaTdl60zar8/rAeuOa09BJkmv c/pbgv6JzXfRRQXWZTqD5W7Yj1SnAtAkpmuQ53AZKX4+Lrfo5DMVMgeqPQlQdVnu/M /1ZlSrUDWIejKdBHn0cWVsl0x9fvE7kBAt7g+gMc= 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 6.18 0710/1518] md: skip redundant raid_disks update when value is unchanged Date: Sat, 12 Sep 2026 08:47:59 +0200 Message-ID: <20260912065639.493638618@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065623.398859879@linuxfoundation.org> References: <20260912065623.398859879@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 6.18-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 93e5774618126..debe07631d6ba 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -4421,9 +4421,10 @@ 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