From patchwork Mon Jan 22 10:51:03 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johannes Thumshirn X-Patchwork-Id: 13525133 Received: from esa2.hgst.iphmx.com (esa2.hgst.iphmx.com [68.232.143.124]) (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 51F553A8CC; Mon, 22 Jan 2024 10:51:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=68.232.143.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705920676; cv=none; b=EoKy70obk1nr+4WaOmOuxhicTmHENfJYzyLGZbzWn4SzeZt/E/0XcEcCk3YR4I+jTFV2c1ZaBxDzvWf61DF6V3xheKPJj0sAqzMMNJ0UgdnB2T0lYxcYK15HfJoWs+RFN0R6Hi1sJ/QbD8dBH0KZ4ulQBkbSCRHCYFtg/aMtW18= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705920676; c=relaxed/simple; bh=wwPu7DkLQsyhuvNCEpSxZndOrmqP3sMH0uvfkUU5WjI=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=nnz1YhM9VBOmbhrVFD6E9nxLWTChC31yNr8O3xtnwPDrz3jqxmUtoUloa5JK4avs30RLm23WhBz+cV6Pd4hlth2SUTFqrwounJIJ4i02Mo5711Bipyk8nAhVzpXfl1SfaHy+LzDUWcurRC5DIqEOhiFpz8blCTKXeOmjwIb6bk4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=wdc.com; spf=pass smtp.mailfrom=wdc.com; dkim=pass (2048-bit key) header.d=wdc.com header.i=@wdc.com header.b=CyK9yyEa; arc=none smtp.client-ip=68.232.143.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=wdc.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=wdc.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=wdc.com header.i=@wdc.com header.b="CyK9yyEa" DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=wdc.com; i=@wdc.com; q=dns/txt; s=dkim.wdc.com; t=1705920674; x=1737456674; h=from:date:subject:mime-version:content-transfer-encoding: message-id:references:in-reply-to:to:cc; bh=wwPu7DkLQsyhuvNCEpSxZndOrmqP3sMH0uvfkUU5WjI=; b=CyK9yyEaEfY5v61PVmUgs1XL0ZyVIRFIiKqhKn7xvk80PI88KmJH9vWo lKq7SO9expegn46DXTl94Ew6m50byh7NYtzvP1p0AwhK7JSuIPerV1Mmq dRudOfE+F4hvxJNv0ovJmnhqHWmcyLfjWuKFqdFUgH2m5SJAPkLdr73N6 uyyL+UE/RNR5Qr3PQvZAyk3GxjGFquq76y0EmGTSLcfivekJEbupOiWc8 lsezGsiC3mYceHBl7OxOaim9KFRy893H/UW6U+0ParEgfvfXBn6Apgh8S iNq2PjudNQFwDXAFuj56QaawYkiAejr9TKTxMLKqgcanhr69JVBzZYFMj g==; X-CSE-ConnectionGUID: rtpBGrOAQ4KF5TsO5NhvAw== X-CSE-MsgGUID: 1Yn1tz85SFKXYv0O2cCmTA== X-IronPort-AV: E=Sophos;i="6.05,211,1701100800"; d="scan'208";a="7427194" Received: from h199-255-45-14.hgst.com (HELO uls-op-cesaep01.wdc.com) ([199.255.45.14]) by ob1.hgst.iphmx.com with ESMTP; 22 Jan 2024 18:51:13 +0800 IronPort-SDR: 32Nba8c8wwwixFwZCqcTkJj+GbHlGSTBGO/sqatOYqqTHtU3//vzSD9K0IkxvQc5sXCl+udusY L38F8EpmmucQ== Received: from uls-op-cesaip02.wdc.com ([10.248.3.37]) by uls-op-cesaep01.wdc.com with ESMTP/TLS/ECDHE-RSA-AES128-GCM-SHA256; 22 Jan 2024 02:01:16 -0800 IronPort-SDR: F3NWE8XuMcyk04xRq9g+JwpM08b7KqYnlodzG8W5bj/2xaqn4Ev5HTjVyo/iC0yRCtAVxQNGzZ qQYASCBRvJEQ== WDCIronportException: Internal Received: from unknown (HELO redsun91.ssa.fujisawa.hgst.com) ([10.149.66.6]) by uls-op-cesaip02.wdc.com with ESMTP; 22 Jan 2024 02:51:12 -0800 From: Johannes Thumshirn Date: Mon, 22 Jan 2024 02:51:03 -0800 Subject: [PATCH 1/2] btrfs: zoned: use rcu list for iterating devices to collect stats Precedence: bulk X-Mailing-List: linux-btrfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240122-reclaim-fix-v1-1-761234a6d005@wdc.com> References: <20240122-reclaim-fix-v1-0-761234a6d005@wdc.com> In-Reply-To: <20240122-reclaim-fix-v1-0-761234a6d005@wdc.com> To: Josef Bacik , David Sterba Cc: Naohiro Aota , linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org, Johannes Thumshirn , Damien Le Moal X-Mailer: b4 0.12.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1705920670; l=1177; i=johannes.thumshirn@wdc.com; s=20230613; h=from:subject:message-id; bh=wwPu7DkLQsyhuvNCEpSxZndOrmqP3sMH0uvfkUU5WjI=; b=guDBNuj3D6sX/OjE2aHJDCGPc1NYt+gvnf6rLifQxGQoHe3WfgKIjsSNl2U3iVo7mZMRAGtW7 z2Xw8qZSCblCVqenWIBIB5/1xuqh2JbO+d9HrCZpCxRaye3xHti2x5i X-Developer-Key: i=johannes.thumshirn@wdc.com; a=ed25519; pk=TGmHKs78FdPi+QhrViEvjKIGwReUGCfa+3LEnGoR2KM= As btrfs_zoned_should_reclaim only has to iterate the device list in order to collect stats on the device's total and used bytes, we don't need to take the full blown mutex, but can iterate the device list in a rcu_read context. Signed-off-by: Johannes Thumshirn Reviewed-by: Naohiro Aota --- fs/btrfs/zoned.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c index 168af9d000d1..b7e7b5a5a6fa 100644 --- a/fs/btrfs/zoned.c +++ b/fs/btrfs/zoned.c @@ -2423,15 +2423,15 @@ bool btrfs_zoned_should_reclaim(struct btrfs_fs_info *fs_info) if (fs_info->bg_reclaim_threshold == 0) return false; - mutex_lock(&fs_devices->device_list_mutex); - list_for_each_entry(device, &fs_devices->devices, dev_list) { + rcu_read_lock(); + list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) { if (!device->bdev) continue; total += device->disk_total_bytes; used += device->bytes_used; } - mutex_unlock(&fs_devices->device_list_mutex); + rcu_read_unlock(); factor = div64_u64(used * 100, total); return factor >= fs_info->bg_reclaim_threshold;