From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 3149022157B; Mon, 13 Oct 2025 13:38:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760362719; cv=none; b=DGE7L3XG5UwRmXE75p85U1F/lHPIYO70atcHr+2j0rUWuYvIee1Tb25Bx1ycttkDmpzb9wZViUe9fs7LSsf1MHTl5opZJNh63Y+cokhrsdIvAPBnk4lzRWEwvOXXyjEJDuhkZQX+sg96iseolrt3yn7GN09IWzxnuQKwmiRTQqM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760362719; c=relaxed/simple; bh=x+PN02ZPz5D3mRsRokGX7FVJjc6Z2tGcmM9hNPlpiWY=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=RV8Gdsnjf4bfYMNSra/c7cdrRFVXqm7Yrm6RiQPS3jgD60siAt6/dRBSPDuAAJot2E7fV11M9CsKPaD9EmmqlqwYjwljJ8w7Dh3ONqLkHlBRbfZUWb8LLnGMrIComp4ZOj3KAFbOQwzmrHDbxzm2LulOTDQE4bC9bsLymTYIDas= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=cSwSb3Vo; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="cSwSb3Vo" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4A31FC4CEE7; Mon, 13 Oct 2025 13:38:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1760362718; bh=x+PN02ZPz5D3mRsRokGX7FVJjc6Z2tGcmM9hNPlpiWY=; h=From:Date:Subject:To:Cc:From; b=cSwSb3Vo+MKugI5i7sOGtx2UjZd2pu7YfoOlMVOSVxXV+DI1Fy5A9XJgX7v5MskgY a15IVS8B0GtsT6Q4iU3teJGk0F3xn/3/xDVsSKI1OfNDcJL++F4XAS0PRD8P9BI1bg aFZApokbE2hIUDHnxI+C5uYDVGR36c/QKGTCpkCi9MutVAkOfHP9iCkII9soMV69WS ym1vWQ4UHoXxaUG1RrvTXSdpIopWDG8Ue78lWJgaTFjMrm3Dc51+49bm9OrEy2FoDo b9KIUC/YFZr74x2981mERFqk4sLjVdR3+qL25j0DUzQUrDmIgSjashd1g8VW+YsqLg UJDKQjyFKLtUw== From: Jeff Layton Date: Mon, 13 Oct 2025 09:38:23 -0400 Subject: [PATCH v6] sunrpc: allocate a separate bvec array for socket sends Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20251013-rq_bvec-v6-1-17982fc64ad2@kernel.org> X-B4-Tracking: v=1; b=H4sIAM4A7WgC/3XMwW4CIRDG8VcxnEszMyyw9OR7mKZZYFBis1tZQ 9qYffeiFzUbj99kfv+LmLlknsXH5iIK1zznaWzDvG1EOAzjnmWObQsC0gjQy3L68pWD9MYMKUK K3nvRvn8Kp/x7K+0+2z7k+TyVv1u44vW6blSUIG0iFRVFq1lvj1xG/n6fyl5cI5VeQGqwJxVg6 PVANqygeoTuDlWD2mKPyoB3wa9g9wAR7rCTKA1ZbWzCwA5XUL+AusGuc9aQBnQuPsFlWf4BeZD w+4MBAAA= X-Change-ID: 20251008-rq_bvec-b66afd0fdbbb To: Chuck Lever , NeilBrown , Olga Kornievskaia , Dai Ngo , Tom Talpey , Trond Myklebust , Anna Schumaker , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , David Howells Cc: Brandon Adams , linux-nfs@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Jeff Layton X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=6563; i=jlayton@kernel.org; h=from:subject:message-id; bh=x+PN02ZPz5D3mRsRokGX7FVJjc6Z2tGcmM9hNPlpiWY=; b=owEBbQKS/ZANAwAKAQAOaEEZVoIVAcsmYgBo7QDU9/NXXhcz6uTsf5HgiW3i25jjTNl00zuUJ ap/2+1CuXSJAjMEAAEKAB0WIQRLwNeyRHGyoYTq9dMADmhBGVaCFQUCaO0A1AAKCRAADmhBGVaC FfmVEACxy6szP7N44Fb117oThIaxorei2ShcJm6UyErf8oCW7hS6KgOFhNfWW9undL8debdXTSP 4qRLYubnEERGLfQExdFcbDkNQD40sUdYtf+4vRtLPibxTR3685nbUmLAP6cHUCkw+xuBxQoucu3 es66h/RbGseo3DGxwwUpDVDFgudh0wIdd/tXZPEkhQJKXwXPyBIPIExiCy2Hd8StuH8t6LH0RE5 hyHOUUH1ounFqO2Ur/0Qk96JA1YGUScP/9CmdICsDT8d5dTn34NbYdZZcHau++0xS/4SWmnnDtq vIz6ijtL/6e0xQPEhqK8Ma40L5I9OzOOlm+Ld8MGRPu6lS/kDlxMVkddXAQ4h38XDkyeVSjt9av O+8rotdENf/Sz4TcN3Ihomh8v3IoyuwWawy6wOJEyyStuMOi+s0pF9kkTsWX1Bfd6ErUpS7tvTU afCjvV4g1STFzcAOKtqVCBZhT4G6nAYusWkDPj9fARiEeTN64sFTUzwZlwb1nlAPgU89vUKtZ+e fAu9z9IL69Y5XT15e4iapID0n5K0UW1RgB96fJ74XFdwecLspjf4ACBf+4XwXmQpK/vXJyKBNEN EjV5JHixvSXRAtsZH3uzuYHvsTiNV5elc8/3NhuH9zJYu7rxC1hSkNYAIUN1y7d0UZKnY+LI0dV NbQUQDa/VTqrtow== X-Developer-Key: i=jlayton@kernel.org; a=openpgp; fpr=4BC0D7B24471B2A184EAF5D3000E684119568215 svc_tcp_sendmsg() calls xdr_buf_to_bvec() with the second slot of rq_bvec as the start, but doesn't reduce the array length by one, which could lead to an array overrun. Also, rq_bvec is always rq_maxpages in length, which can be too short in some cases, since the TCP record marker consumes a slot. Fix both problems by adding a separate bvec array to the svc_sock that is specifically for sending. For TCP, make this array one slot longer than rq_maxpages, to account for the record marker. For UDP, only allocate as large an array as we need since it's limited to 64k of payload. Signed-off-by: Jeff Layton --- Another update based on Neil's feedback. This version allocates the array when the socket is allocated, and fixes the UDP length calculation. --- Changes in v6: - allocate sk_bvec in ->xpo_create - fix the array-length calculation for UDP - Link to v5: https://lore.kernel.org/r/20251010-rq_bvec-v5-1-44976250199d@kernel.org Changes in v5: - reduce the size of sk_bvec on UDP sockets - Link to v4: https://lore.kernel.org/r/20251010-rq_bvec-v4-1-627567f1ce91@kernel.org Changes in v4: - switch to allocating a separate bvec for sends in the svc_sock - Link to v3: https://lore.kernel.org/r/20251009-rq_bvec-v3-0-57181360b9cb@kernel.org Changes in v3: - Add rq_bvec_len field and use it in appropriate places - Link to v2: https://lore.kernel.org/r/20251008-rq_bvec-v2-0-823c0a85a27c@kernel.org Changes in v2: - Better changelog message for patch #2 - Link to v1: https://lore.kernel.org/r/20251008-rq_bvec-v1-0-7f23d32d75e5@kernel.org --- include/linux/sunrpc/svcsock.h | 3 +++ net/sunrpc/svcsock.c | 54 ++++++++++++++++++++++++++++++++++++------ 2 files changed, 50 insertions(+), 7 deletions(-) diff --git a/include/linux/sunrpc/svcsock.h b/include/linux/sunrpc/svcsock.h index 963bbe251e52109a902f6b9097b6e9c3c23b1fd8..de37069aba90899be19b1090e6e90e509a3cf530 100644 --- a/include/linux/sunrpc/svcsock.h +++ b/include/linux/sunrpc/svcsock.h @@ -26,6 +26,9 @@ struct svc_sock { void (*sk_odata)(struct sock *); void (*sk_owspace)(struct sock *); + /* For sends (protected by xpt_mutex) */ + struct bio_vec *sk_bvec; + /* private TCP part */ /* On-the-wire fragment header: */ __be32 sk_marker; diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c index 0cb9c4d457453b26db29f08985b056c3f8d59447..e979505a21b69267a10d39f9084b557db4c9369c 100644 --- a/net/sunrpc/svcsock.c +++ b/net/sunrpc/svcsock.c @@ -68,6 +68,16 @@ #define RPCDBG_FACILITY RPCDBG_SVCXPRT +/* + * For UDP: + * 1 for header page + * 16 for up to 64kb of payload + 1 in case it's not aligned + * 1 for tail page + */ +enum { + SUNRPC_MAX_UDP_SENDPAGES = 1 + 16 + 1 + 1 +}; + /* To-do: to avoid tying up an nfsd thread while waiting for a * handshake request, the request could instead be deferred. */ @@ -740,14 +750,14 @@ static int svc_udp_sendto(struct svc_rqst *rqstp) if (svc_xprt_is_dead(xprt)) goto out_notconn; - count = xdr_buf_to_bvec(rqstp->rq_bvec, rqstp->rq_maxpages, xdr); + count = xdr_buf_to_bvec(svsk->sk_bvec, SUNRPC_MAX_UDP_SENDPAGES, xdr); - iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, rqstp->rq_bvec, + iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, svsk->sk_bvec, count, rqstp->rq_res.len); err = sock_sendmsg(svsk->sk_sock, &msg); if (err == -ECONNREFUSED) { /* ICMP error on earlier request. */ - iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, rqstp->rq_bvec, + iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, svsk->sk_bvec, count, rqstp->rq_res.len); err = sock_sendmsg(svsk->sk_sock, &msg); } @@ -1236,19 +1246,19 @@ static int svc_tcp_sendmsg(struct svc_sock *svsk, struct svc_rqst *rqstp, int ret; /* The stream record marker is copied into a temporary page - * fragment buffer so that it can be included in rq_bvec. + * fragment buffer so that it can be included in sk_bvec. */ buf = page_frag_alloc(&svsk->sk_frag_cache, sizeof(marker), GFP_KERNEL); if (!buf) return -ENOMEM; memcpy(buf, &marker, sizeof(marker)); - bvec_set_virt(rqstp->rq_bvec, buf, sizeof(marker)); + bvec_set_virt(svsk->sk_bvec, buf, sizeof(marker)); - count = xdr_buf_to_bvec(rqstp->rq_bvec + 1, rqstp->rq_maxpages, + count = xdr_buf_to_bvec(svsk->sk_bvec + 1, rqstp->rq_maxpages, &rqstp->rq_res); - iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, rqstp->rq_bvec, + iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, svsk->sk_bvec, 1 + count, sizeof(marker) + rqstp->rq_res.len); ret = sock_sendmsg(svsk->sk_sock, &msg); page_frag_free(buf); @@ -1393,6 +1403,20 @@ void svc_sock_update_bufs(struct svc_serv *serv) spin_unlock_bh(&serv->sv_lock); } +static int svc_sock_sendpages(struct svc_serv *serv, struct socket *sock, int flags) +{ + switch (sock->type) { + case SOCK_STREAM: + /* +1 for TCP record marker */ + if (flags & SVC_SOCK_TEMPORARY) + return svc_serv_maxpages(serv) + 1; + return 0; + case SOCK_DGRAM: + return SUNRPC_MAX_UDP_SENDPAGES; + } + return -EINVAL; +} + /* * Initialize socket for RPC use and create svc_sock struct */ @@ -1403,12 +1427,26 @@ static struct svc_sock *svc_setup_socket(struct svc_serv *serv, struct svc_sock *svsk; struct sock *inet; int pmap_register = !(flags & SVC_SOCK_ANONYMOUS); + int sendpages; unsigned long pages; + sendpages = svc_sock_sendpages(serv, sock, flags); + if (sendpages < 0) + return ERR_PTR(sendpages); + pages = svc_serv_maxpages(serv); svsk = kzalloc(struct_size(svsk, sk_pages, pages), GFP_KERNEL); if (!svsk) return ERR_PTR(-ENOMEM); + + if (sendpages) { + svsk->sk_bvec = kcalloc(sendpages, sizeof(*svsk->sk_bvec), GFP_KERNEL); + if (!svsk->sk_bvec) { + kfree(svsk); + return ERR_PTR(-ENOMEM); + } + } + svsk->sk_maxpages = pages; inet = sock->sk; @@ -1420,6 +1458,7 @@ static struct svc_sock *svc_setup_socket(struct svc_serv *serv, inet->sk_protocol, ntohs(inet_sk(inet)->inet_sport)); if (err < 0) { + kfree(svsk->sk_bvec); kfree(svsk); return ERR_PTR(err); } @@ -1637,5 +1676,6 @@ static void svc_sock_free(struct svc_xprt *xprt) sock_release(sock); page_frag_cache_drain(&svsk->sk_frag_cache); + kfree(svsk->sk_bvec); kfree(svsk); } --- base-commit: 05d2192090744b16ce05bd221c459a9357c17525 change-id: 20251008-rq_bvec-b66afd0fdbbb Best regards, -- Jeff Layton