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 3C6FE2264A3 for ; Tue, 22 Sep 2026 01:58:01 +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=1790042282; cv=none; b=gjbgs0LlvTxwJ09L5x+XwOTBXp+NUVoHneJnCoUuv1oGDgNTk7g5dtuAfjnlGAFHcRV65x06IqXhx0nFQkmD8uJZlXFcTab0oV7cmQTVP03pU2WKAgVhBar7nN4Zqo3Yk9PkgObTXx6PGPUjc1p3O7CBaf6MLwkG9RUVpVqgHK4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790042282; c=relaxed/simple; bh=M1FkE5CCB7kCUNd9cSZoeR9MulEH9PT4X5r6O46rp6w=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=dsJW9ojyeuqnLq4XfjnhtHVtl+1WpIXDWdmwAwtNr0vfHAM4hsOXOTFpk/guAWupAvzAOVomQJTAFPPpUj11YWUb86wrtZDvaZe9AK5cMTR6dSrdn8Lo0SGVo8giqKKffcBCu+RULWP+eMA19gm6/9GacN7eZSofxSWzY+AbnDA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QI3p2ywb; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="QI3p2ywb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CC60B1F00893; Tue, 22 Sep 2026 01:58:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790042281; bh=M1FkE5CCB7kCUNd9cSZoeR9MulEH9PT4X5r6O46rp6w=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=QI3p2ywbtvfOcfkNOHdpoLhJIsCWrBd5jH4Ug76ozbNfxfjS4QISh2URJvzLUKvew FC9WHmTCcSS3bRLAHtHpaxuKcXkx8IzyI7yVUnvWdYvcAdktFWbUWTcxQRr76ioGj3 nW150Q1HcBkOarVEidMd/vDluAGJNlCiWG3TU+CcjrbfE2gzr2wI6bv8DknF29i3mJ 8KsK/xJvK4DiISqSR9g0C9yFO/WygEV9EFWR8VzZ3v+t45QPfhjI9NkOdJXGY64cNJ vXuFFGUQdjftEyhJewTFCsQJlmhfTUDzsJa4efV/c6sUbutXcDWelyg42VgFF1CZbZ bKxzXDkWE26rA== From: sashiko-bot@kernel.org Subject: Re: [PATCH v1 3/5] svcrdma: fix a page leak in backchannel sends Reply-To: sashiko-reviews@lists.linux.dev To: "Chuck Lever" Cc: "Anna Schumaker" , "Chuck Lever" , "Jeff Layton" , linux-rdma@vger.kernel.org In-Reply-To: <20260922015128.240977-3-cel@kernel.org> References: <20260922015128.240977-1-cel@kernel.org> <20260922015128.240977-3-cel@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Tue, 22 Sep 2026 01:58:00 +0000 Message-Id: <20260922015800.CC60B1F00893@smtp.kernel.org> Precedence: bulk X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > svc_rdma_bc_sendto() takes an extra reference on the page that > holds the backchannel Call message, so that the page is not > returned to the allocator while the Send that reads it is still > posted. Send completion once dropped that reference, back when the > page sat in the send context's page array. Commit 99722fe4d5a6 > ("svcrdma: Persistently allocate and DMA-map Send buffers") > switched the backchannel to svc_rdma_map_reply_msg(), which > DMA-maps the buffer and records no pages. Send completion no > longer touches the page, but the get_page() stayed. >=20 > xprt_rdma_bc_free() drops the allocation reference and nothing > drops the extra one, so every backchannel Call sent over RPC/RDMA > leaks its send buffer page. >=20 > The extra reference is still needed. A Call at or above > RPCRDMA_PULLUP_THRESH is DMA-mapped in place. The RPC client frees > rq_buffer when the callback task times out or is killed, whether > or not the Send has completed. Record the page in the send > context's page array so that svc_rdma_send_ctxt_release() drops > the reference after Send completion. >=20 > Fixes: 99722fe4d5a6 ("svcrdma: Persistently allocate and DMA-map Send buf= fers") > Signed-off-by: Chuck Lever Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260922015128.2409= 77-1-cel@kernel.org?part=3D3