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 81F676EB72; Mon, 8 Apr 2024 13:55:56 +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=1712584556; cv=none; b=du/kLiVq5cGD9NW3HBiaJ690GTdnsbsj1m7G7ttiQ4cAa8lfaICaonl1EdrRQA1+I2rYzbWQA/sAHPVIiB/A7nL4AmIngkkF6+dIsuRxB4WXUIEJz6eZrqdmMC8yesLUSJUzHAd1icedAym+aWVhIOZQ1t0J7Xx44KawY+GQ+Mg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712584556; c=relaxed/simple; bh=+qZqCvjexF+5X7x7nSshNgtsd83o2voHIwlx4ZfxIcY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NeEmmcoWe9NJ+1E0CJTTNDwcIP+Q/Eut7VTpitElbU6JWIQuyHaCy0D6DTF+ScqGi8c0BC5qG9mz72F8AL4md3ComYDQuJ2BK14ngasq3TxN7PLc6VnmN+Xt2tk+nLdTDoZNyqbtbjIiG4gUVuMpKIvXuQidgJWb5snTTNIICyQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=g/5aVPt2; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="g/5aVPt2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 07DC9C433F1; Mon, 8 Apr 2024 13:55:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1712584556; bh=+qZqCvjexF+5X7x7nSshNgtsd83o2voHIwlx4ZfxIcY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=g/5aVPt2K1b0fKxjxvmc1mJxa9mRV9a+5ounPE4grKNN/MTyaaRqwQqx3MezMwnYm TUc/BjrKnAHBSnvw/HPJblnnR+5TZmzoXcd7A06mnYj2QBKMmBY1othWWO6fTcCZyH O/5GTIZDSwHh5fdGGR3cDr+xlmW2e39XUNxULmv4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Chuck Lever Subject: [PATCH 5.15 451/690] NFSD: Cap rsize_bop result based on send buffer size Date: Mon, 8 Apr 2024 14:55:17 +0200 Message-ID: <20240408125415.993634721@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240408125359.506372836@linuxfoundation.org> References: <20240408125359.506372836@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chuck Lever [ Upstream commit 76ce4dcec0dc08a032db916841ddc4e3998be317 ] Since before the git era, NFSD has conserved the number of pages held by each nfsd thread by combining the RPC receive and send buffers into a single array of pages. This works because there are no cases where an operation needs a large RPC Call message and a large RPC Reply at the same time. Once an RPC Call has been received, svc_process() updates svc_rqst::rq_res to describe the part of rq_pages that can be used for constructing the Reply. This means that the send buffer (rq_res) shrinks when the received RPC record containing the RPC Call is large. Add an NFSv4 helper that computes the size of the send buffer. It replaces svc_max_payload() in spots where svc_max_payload() returns a value that might be larger than the remaining send buffer space. Callers who need to know the transport's actual maximum payload size will continue to use svc_max_payload(). Signed-off-by: Chuck Lever --- fs/nfsd/nfs4proc.c | 48 +++++++++++++++++++++++----------------------- 1 file changed, 24 insertions(+), 24 deletions(-) diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c index 59f675f194ebb..2e8f8b9fa3aeb 100644 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -2765,6 +2765,22 @@ nfsd4_proc_compound(struct svc_rqst *rqstp) #define op_encode_channel_attrs_maxsz (6 + 1 + 1) +/* + * The _rsize() helpers are invoked by the NFSv4 COMPOUND decoder, which + * is called before sunrpc sets rq_res.buflen. Thus we have to compute + * the maximum payload size here, based on transport limits and the size + * of the remaining space in the rq_pages array. + */ +static u32 nfsd4_max_payload(const struct svc_rqst *rqstp) +{ + u32 buflen; + + buflen = (rqstp->rq_page_end - rqstp->rq_next_page) * PAGE_SIZE; + buflen -= rqstp->rq_auth_slack; + buflen -= rqstp->rq_res.head[0].iov_len; + return min_t(u32, buflen, svc_max_payload(rqstp)); +} + static u32 nfsd4_only_status_rsize(const struct svc_rqst *rqstp, const struct nfsd4_op *op) { @@ -2810,9 +2826,9 @@ static u32 nfsd4_getattr_rsize(const struct svc_rqst *rqstp, u32 ret = 0; if (bmap0 & FATTR4_WORD0_ACL) - return svc_max_payload(rqstp); + return nfsd4_max_payload(rqstp); if (bmap0 & FATTR4_WORD0_FS_LOCATIONS) - return svc_max_payload(rqstp); + return nfsd4_max_payload(rqstp); if (bmap1 & FATTR4_WORD1_OWNER) { ret += IDMAP_NAMESZ + 4; @@ -2872,10 +2888,7 @@ static u32 nfsd4_open_rsize(const struct svc_rqst *rqstp, static u32 nfsd4_read_rsize(const struct svc_rqst *rqstp, const struct nfsd4_op *op) { - u32 maxcount = 0, rlen = 0; - - maxcount = svc_max_payload(rqstp); - rlen = min(op->u.read.rd_length, maxcount); + u32 rlen = min(op->u.read.rd_length, nfsd4_max_payload(rqstp)); return (op_encode_hdr_size + 2 + XDR_QUADLEN(rlen)) * sizeof(__be32); } @@ -2883,8 +2896,7 @@ static u32 nfsd4_read_rsize(const struct svc_rqst *rqstp, static u32 nfsd4_read_plus_rsize(const struct svc_rqst *rqstp, const struct nfsd4_op *op) { - u32 maxcount = svc_max_payload(rqstp); - u32 rlen = min(op->u.read.rd_length, maxcount); + u32 rlen = min(op->u.read.rd_length, nfsd4_max_payload(rqstp)); /* * If we detect that the file changed during hole encoding, then we * recover by encoding the remaining reply as data. This means we need @@ -2898,10 +2910,7 @@ static u32 nfsd4_read_plus_rsize(const struct svc_rqst *rqstp, static u32 nfsd4_readdir_rsize(const struct svc_rqst *rqstp, const struct nfsd4_op *op) { - u32 maxcount = 0, rlen = 0; - - maxcount = svc_max_payload(rqstp); - rlen = min(op->u.readdir.rd_maxcount, maxcount); + u32 rlen = min(op->u.readdir.rd_maxcount, nfsd4_max_payload(rqstp)); return (op_encode_hdr_size + op_encode_verifier_maxsz + XDR_QUADLEN(rlen)) * sizeof(__be32); @@ -3040,10 +3049,7 @@ static u32 nfsd4_copy_notify_rsize(const struct svc_rqst *rqstp, static u32 nfsd4_getdeviceinfo_rsize(const struct svc_rqst *rqstp, const struct nfsd4_op *op) { - u32 maxcount = 0, rlen = 0; - - maxcount = svc_max_payload(rqstp); - rlen = min(op->u.getdeviceinfo.gd_maxcount, maxcount); + u32 rlen = min(op->u.getdeviceinfo.gd_maxcount, nfsd4_max_payload(rqstp)); return (op_encode_hdr_size + 1 /* gd_layout_type*/ + @@ -3093,10 +3099,7 @@ static u32 nfsd4_seek_rsize(const struct svc_rqst *rqstp, static u32 nfsd4_getxattr_rsize(const struct svc_rqst *rqstp, const struct nfsd4_op *op) { - u32 maxcount, rlen; - - maxcount = svc_max_payload(rqstp); - rlen = min_t(u32, XATTR_SIZE_MAX, maxcount); + u32 rlen = min_t(u32, XATTR_SIZE_MAX, nfsd4_max_payload(rqstp)); return (op_encode_hdr_size + 1 + XDR_QUADLEN(rlen)) * sizeof(__be32); } @@ -3110,10 +3113,7 @@ static u32 nfsd4_setxattr_rsize(const struct svc_rqst *rqstp, static u32 nfsd4_listxattrs_rsize(const struct svc_rqst *rqstp, const struct nfsd4_op *op) { - u32 maxcount, rlen; - - maxcount = svc_max_payload(rqstp); - rlen = min(op->u.listxattrs.lsxa_maxcount, maxcount); + u32 rlen = min(op->u.listxattrs.lsxa_maxcount, nfsd4_max_payload(rqstp)); return (op_encode_hdr_size + 4 + XDR_QUADLEN(rlen)) * sizeof(__be32); } -- 2.43.0