Return-Path: linux-nfs-owner@vger.kernel.org Received: from fieldses.org ([174.143.236.118]:43362 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751039AbaEVTce (ORCPT ); Thu, 22 May 2014 15:32:34 -0400 From: "J. Bruce Fields" To: linux-nfs@vger.kernel.org Cc: Christoph Hellwig , "J. Bruce Fields" Subject: [PATCH 11/52] nfsd4: fix encoding of out-of-space replies Date: Thu, 22 May 2014 15:31:46 -0400 Message-Id: <1400787148-25941-12-git-send-email-bfields@redhat.com> In-Reply-To: <1400787148-25941-1-git-send-email-bfields@redhat.com> References: <1400787148-25941-1-git-send-email-bfields@redhat.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: From: "J. Bruce Fields" If nfsd4_check_resp_size() returns an error then we should really be truncating the reply here, otherwise we may leave extra garbage at the end of the rpc reply. Also add a warning to catch any cases where our reply-size estimates may be wrong in the case of a non-idempotent operation. Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4proc.c | 9 +++++++++ fs/nfsd/nfs4xdr.c | 17 ++++++++++++++++- fs/nfsd/xdr4.h | 2 ++ 3 files changed, 27 insertions(+), 1 deletion(-) diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c index 747d6a8..db14965 100644 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -1859,6 +1859,15 @@ static struct nfsd4_operation nfsd4_ops[] = { }, }; +void warn_on_nonidempotent_op(struct nfsd4_op *op) +{ + if (OPDESC(op)->op_flags & OP_MODIFIES_SOMETHING) { + pr_err("unable to encode reply to nonidempotent op %d (%s)\n", + op->opnum, nfsd4_op_name(op->opnum)); + WARN_ON_ONCE(1); + } +} + #ifdef NFSD_DEBUG static const char *nfsd4_op_name(unsigned opnum) { diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index 1879250..24ba652 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -3637,6 +3637,7 @@ nfsd4_encode_operation(struct nfsd4_compoundres *resp, struct nfsd4_op *op) { struct nfs4_stateowner *so = resp->cstate.replay_owner; __be32 *statp; + nfsd4_enc encoder; __be32 *p; RESERVE_SPACE(8); @@ -3648,10 +3649,24 @@ nfsd4_encode_operation(struct nfsd4_compoundres *resp, struct nfsd4_op *op) goto status; BUG_ON(op->opnum < 0 || op->opnum >= ARRAY_SIZE(nfsd4_enc_ops) || !nfsd4_enc_ops[op->opnum]); - op->status = nfsd4_enc_ops[op->opnum](resp, op->status, &op->u); + encoder = nfsd4_enc_ops[op->opnum]; + op->status = encoder(resp, op->status, &op->u); /* nfsd4_check_resp_size guarantees enough room for error status */ if (!op->status) op->status = nfsd4_check_resp_size(resp, 0); + if (op->status == nfserr_resource || + op->status == nfserr_rep_too_big || + op->status == nfserr_rep_too_big_to_cache) { + /* + * The operation may have already been encoded or + * partially encoded. No op returns anything additional + * in the case of one of these three errors, so we can + * just truncate back to after the status. But it's a + * bug if we had to do this on a non-idempotent op: + */ + warn_on_nonidempotent_op(op); + resp->xdr.p = statp + 1; + } if (so) { so->so_replay.rp_status = op->status; so->so_replay.rp_buflen = (char *)resp->xdr.p diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h index f62a055..15ca477 100644 --- a/fs/nfsd/xdr4.h +++ b/fs/nfsd/xdr4.h @@ -536,6 +536,8 @@ static inline bool nfsd4_last_compound_op(struct svc_rqst *rqstp) return argp->opcnt == resp->opcnt; } +void warn_on_nonidempotent_op(struct nfsd4_op *op); + #define NFS4_SVC_XDRSIZE sizeof(struct nfsd4_compoundargs) static inline void -- 1.9.0