From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 877C0C10F13 for ; Mon, 8 Apr 2019 16:02:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2D7BE20857 for ; Mon, 8 Apr 2019 16:02:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=umich.edu header.i=@umich.edu header.b="G5IluwGZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727838AbfDHQCq (ORCPT ); Mon, 8 Apr 2019 12:02:46 -0400 Received: from mail-vk1-f193.google.com ([209.85.221.193]:38813 "EHLO mail-vk1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727331AbfDHQCq (ORCPT ); Mon, 8 Apr 2019 12:02:46 -0400 Received: by mail-vk1-f193.google.com with SMTP id h71so3152049vkf.5; Mon, 08 Apr 2019 09:02:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=umich.edu; s=google-2016-06-03; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=9epOGeC9gn8GWo1SCiYzHFa0RftVGkIwMM9J2EseCxM=; b=G5IluwGZk824G2IPEHCMtV/dqY3nh3L/D/Hud5BwGeQWZSnX+bMn2IVWxUgiEf5bsg WB0esTEemxX5WUp1EiS5FuRI50kz0/1HYQPZ+IwhK4OZFul4NLWQ2jKM3tIrwv7jZxWR i6WcvQFMLiuPGhNXrmWAmB+9KhrYoywc4CPoeREU6WLkjq/SmoqeldMgvIakLOpNMbEU yds+cubjNSC0KJYN493fZe3gWLrUPxcqexea8yz9I3uIsFMpqVmM0k7Kva9IyTOYacQd RWDkcgpEG21HfWD1Zo2fHc8mdNAxh5eGMKl1FTrEfxhbxvP/7HIvYQJmw/4UcJzkKdfQ baKg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=9epOGeC9gn8GWo1SCiYzHFa0RftVGkIwMM9J2EseCxM=; b=j+EQgtQ47SJU6MCISALwoB+d2h4ob0SoYfv7VQhuF5zorANs0hx8g4XJfmjEY4OCZK r/UW+4hOVDV7kFwHvx0428m0+pSdyWQKQSxolwAH5j1kolmW+K+tloTy9899W0qBcpCP Sd+evigMS1wp7oZWMebwLixw+LalWqKrzbY3uRHTj70B0hWYQLia4iQL3OqhKdu6Hl05 LSU59i6/W10lwTLOy7WB3lMXA9yQGvwWnSbe7ZhESQMdAVuoyTGBCnA0UeN77Rr2cCuK o5iyRSZBdh+57qOmDOnBPwlHM1e7ITKgQTKHNz/bOvanMbdd6gtqhlT2Y6c2lTwwx5pz 0Umw== X-Gm-Message-State: APjAAAUDXLfQ1JmzU6zreiGh8AL11dMtafM3JwVAl5LCBy21gQHmPHf9 s9x9fOjELQE2Arc1zOaInJYPSqFu6w2t+J+eo20= X-Google-Smtp-Source: APXvYqx7u5SMgjzE7K5cFDuiknHhZ3F7n7P90+oSRqZyyYhsU8s8AM25n/MLcOiydhoiLlkdTQOSqRrHiOCM0dc2wag= X-Received: by 2002:a1f:23c5:: with SMTP id j188mr16287998vkj.39.1554739364933; Mon, 08 Apr 2019 09:02:44 -0700 (PDT) MIME-Version: 1.0 References: <20190211161920.2817.20881.stgit@manet.1015granger.net> <20190211162525.2817.60645.stgit@manet.1015granger.net> <0157F163-7554-413C-ACCA-FE6646C04716@oracle.com> <5AC0653D-3D4E-4C0C-BFE3-616BF32589CB@oracle.com> <19341226-AE0F-4C94-B7CD-AE14CCB456AF@oracle.com> <1E4939AD-F0AE-47EF-81E2-B919FB203B76@oracle.com> In-Reply-To: From: Olga Kornievskaia Date: Mon, 8 Apr 2019 12:02:33 -0400 Message-ID: Subject: Re: [PATCH v1 20/23] NFS: Account for XDR pad of buf->pages To: Chuck Lever Cc: Anna Schumaker , linux-rdma , Linux NFS Mailing List Content-Type: text/plain; charset="UTF-8" Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org On Mon, Apr 8, 2019 at 11:50 AM Olga Kornievskaia wrote: > > On Mon, Apr 8, 2019 at 11:26 AM Olga Kornievskaia wrote: > > > > On Mon, Apr 8, 2019 at 11:21 AM Olga Kornievskaia wrote: > > > > > > On Mon, Apr 8, 2019 at 10:43 AM Chuck Lever wrote: > > > > > > > > > > > > > > > > > On Apr 8, 2019, at 10:36 AM, Olga Kornievskaia wrote: > > > > > > > > > > On Fri, Apr 5, 2019 at 3:42 PM Chuck Lever wrote: > > > > >> > > > > >> > > > > >> > > > > >>> On Apr 5, 2019, at 3:27 PM, Olga Kornievskaia wrote: > > > > >>> > > > > >>> On Fri, Apr 5, 2019 at 3:23 PM Chuck Lever wrote: > > > > >>>> > > > > >>>> > > > > >>>> > > > > >>>>> On Apr 5, 2019, at 3:17 PM, Olga Kornievskaia wrote: > > > > >>>>> > > > > >>>>> On Fri, Apr 5, 2019 at 1:51 PM Chuck Lever wrote: > > > > >>>>>> > > > > >>>>>> > > > > >>>>>> > > > > >>>>>>> On Apr 5, 2019, at 1:36 PM, Olga Kornievskaia wrote: > > > > >>>>>>> > > > > >>>>>>> Hi Chuck, > > > > >>>>>>> > > > > >>>>>>> This patch break ACLs. After applying this patch nfs4_getfacl fails > > > > >>>>>>> (it fails within xdr and returns ENOTSUPP). Any ideas why? > > > > >>>>>> > > > > >>>>>> Possibly the macro that defines the maximum size of the reply > > > > >>>>>> is incorrect. > > > > >>>>>> > > > > >>>>> > > > > >>>>> This also breaks FS_LOCATION. I'm going to go on the limb here and say > > > > >>>>> that it probably breaks whatever else it modified. > > > > >>>> > > > > >>>> It modifies READ, READDIR, and READLINK. Are those broken? > > > > >>> > > > > >>> I don't know how to test READLINK.. but I think READ/READDIR work OK > > > > >>> otherwise folks would have noticed it (I gather ACL and FS_LOCATION > > > > >>> testing doesn't happen frequently). > > > > >> > > > > >> I guess I don't have any NFSv4 ACL or FS_LOCATIONS regressions > > > > >> tests in my automated unit tests. > > > > >> > > > > >> > > > > >>>>> The question is: can't we just revert it?? > > > > >>>> > > > > >>>> Why not "root cause" it first? > > > > >>> > > > > >>> I'm trying :-/ I was just fishing to see how important the change was. > > > > >> > > > > >> Try reverting just this hunk: > > > > > > > > > > That doesn't help. It seems to be this piece that's causing issues > > > > > hdrsize += RPC_REPHDRSIZE + req->rq_cred->cr_auth->au_rslack - 1 > > > > > > > > > > With this there is an extra byte (in front) in the buffer when (ACL) > > > > > operation is decoded. > > > > > > > > How do you know there isn't a latent bug in the getfacl decoder? > > > > > > I don't. All I know is that it passed tests before and now it doesn't. > > > > Also this bug will have to be in both getfacl and fs_location code. > > What they both share is xd_enter_page() code that now with new > > semantics makes the buffer point to the wrong place. READLINK uses xdr_read_pages() function which sets the xdr->p and accounts for padding which xdr_enter_page() does not. > > > > > > How are you reproducing this issue? I can try it here later today. > > > > > > The issue was found running xfstest nfs/001. However, you don't need > > > that: (1) mount (2) nfs4_getfacl > > > > > > To understand a patch, does it fix a problem with READLINK or is the > > > an optimization? > > So this "fixes" it but this don't look really good. > > diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c > index cfcabc3..f2a5553 100644 > --- a/fs/nfs/nfs4xdr.c > +++ b/fs/nfs/nfs4xdr.c > > @@ -5280,6 +5280,7 @@ static int decode_getacl(struct xdr_stream *xdr, > struct rpc_rqst *req, > goto out; > xdr_enter_page(xdr, xdr->buf->page_len); > + xdr->p++; > > /* Calculate the offset of the page data */ > pg_offset = xdr->buf->head[0].iov_len; > @@ -6949,6 +6950,7 @@ static int nfs4_xdr_dec_fs_locations(struct rpc_rqst *req, > goto out; > if (res->migration) { > xdr_enter_page(xdr, PAGE_SIZE); > + xdr->p++; > status = decode_getfattr_generic(xdr, > &res->fs_locations->fattr, > NULL, res->fs_locations, > @@ -6962,6 +6964,7 @@ static int nfs4_xdr_dec_fs_locations(struct rpc_rqst *req, > if (status) > goto out; > xdr_enter_page(xdr, PAGE_SIZE); > + xdr->p++; > status = decode_getfattr_generic(xdr, > &res->fs_locations->fattr, > NULL, res->fs_locations, > > > > > > > > > > > > > > > > > >> diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c > > > > >> index d0fa18d..6d9d5e2 100644 > > > > >> --- a/fs/nfs/nfs4xdr.c > > > > >> +++ b/fs/nfs/nfs4xdr.c > > > > >> @@ -284,14 +284,14 @@ static int decode_layoutget(struct xdr_stream *xdr, struct rpc_rqst *req, > > > > >> #define decode_delegreturn_maxsz (op_decode_hdr_maxsz) > > > > >> #define encode_getacl_maxsz (encode_getattr_maxsz) > > > > >> #define decode_getacl_maxsz (op_decode_hdr_maxsz + \ > > > > >> - nfs4_fattr_bitmap_maxsz + 1) > > > > >> + nfs4_fattr_bitmap_maxsz + 1 + 1) > > > > >> #define encode_setacl_maxsz (op_encode_hdr_maxsz + \ > > > > >> encode_stateid_maxsz + 3) > > > > >> #define decode_setacl_maxsz (decode_setattr_maxsz) > > > > >> #define encode_fs_locations_maxsz \ > > > > >> (encode_getattr_maxsz) > > > > >> #define decode_fs_locations_maxsz \ > > > > >> - (0) > > > > >> + (1) > > > > >> #define encode_secinfo_maxsz (op_encode_hdr_maxsz + nfs4_name_maxsz) > > > > >> #define decode_secinfo_maxsz (op_decode_hdr_maxsz + 1 + ((NFS_MAX_SECFLAVORS * (16 + GSS_OID_MAX_LEN)) / 4)) > > > > >> > > > > >> > > > > >>>>>>> On Mon, Feb 11, 2019 at 11:25 AM Chuck Lever wrote: > > > > >>>>>>>> > > > > >>>>>>>> Certain NFS results (eg. READLINK) might expect a data payload that > > > > >>>>>>>> is not an exact multiple of 4 bytes. In this case, XDR encoding > > > > >>>>>>>> is required to pad that payload so its length on the wire is a > > > > >>>>>>>> multiple of 4 bytes. The constants that define the maximum size of > > > > >>>>>>>> each NFS result do not appear to account for this extra word. > > > > >>>>>>>> > > > > >>>>>>>> In each case where the data payload is to be received into pages: > > > > >>>>>>>> > > > > >>>>>>>> - 1 word is added to the size of the receive buffer allocated by > > > > >>>>>>>> call_allocate > > > > >>>>>>>> > > > > >>>>>>>> - rpc_inline_rcv_pages subtracts 1 word from @hdrsize so that the > > > > >>>>>>>> extra buffer space falls into the rcv_buf's tail iovec > > > > >>>>>>>> > > > > >>>>>>>> - If buf->pagelen is word-aligned, an XDR pad is not needed and > > > > >>>>>>>> is thus removed from the tail > > > > >>>>>>>> > > > > >>>>>>>> Signed-off-by: Chuck Lever > > > > >>>>>>>> --- > > > > >>>>>>>> fs/nfs/nfs2xdr.c | 6 +++--- > > > > >>>>>>>> fs/nfs/nfs3xdr.c | 10 +++++----- > > > > >>>>>>>> fs/nfs/nfs4xdr.c | 15 ++++++++------- > > > > >>>>>>>> net/sunrpc/clnt.c | 6 +++++- > > > > >>>>>>>> net/sunrpc/xdr.c | 2 ++ > > > > >>>>>>>> 5 files changed, 23 insertions(+), 16 deletions(-) > > > > >>>>>>>> > > > > >>>>>>>> diff --git a/fs/nfs/nfs2xdr.c b/fs/nfs/nfs2xdr.c > > > > >>>>>>>> index 1dcd0fe..a7ed29d 100644 > > > > >>>>>>>> --- a/fs/nfs/nfs2xdr.c > > > > >>>>>>>> +++ b/fs/nfs/nfs2xdr.c > > > > >>>>>>>> @@ -56,11 +56,11 @@ > > > > >>>>>>>> > > > > >>>>>>>> #define NFS_attrstat_sz (1+NFS_fattr_sz) > > > > >>>>>>>> #define NFS_diropres_sz (1+NFS_fhandle_sz+NFS_fattr_sz) > > > > >>>>>>>> -#define NFS_readlinkres_sz (2) > > > > >>>>>>>> -#define NFS_readres_sz (1+NFS_fattr_sz+1) > > > > >>>>>>>> +#define NFS_readlinkres_sz (2+1) > > > > >>>>>>>> +#define NFS_readres_sz (1+NFS_fattr_sz+1+1) > > > > >>>>>>>> #define NFS_writeres_sz (NFS_attrstat_sz) > > > > >>>>>>>> #define NFS_stat_sz (1) > > > > >>>>>>>> -#define NFS_readdirres_sz (1) > > > > >>>>>>>> +#define NFS_readdirres_sz (1+1) > > > > >>>>>>>> #define NFS_statfsres_sz (1+NFS_info_sz) > > > > >>>>>>>> > > > > >>>>>>>> static int nfs_stat_to_errno(enum nfs_stat); > > > > >>>>>>>> diff --git a/fs/nfs/nfs3xdr.c b/fs/nfs/nfs3xdr.c > > > > >>>>>>>> index a54dcf4..110358f 100644 > > > > >>>>>>>> --- a/fs/nfs/nfs3xdr.c > > > > >>>>>>>> +++ b/fs/nfs/nfs3xdr.c > > > > >>>>>>>> @@ -69,13 +69,13 @@ > > > > >>>>>>>> #define NFS3_removeres_sz (NFS3_setattrres_sz) > > > > >>>>>>>> #define NFS3_lookupres_sz (1+NFS3_fh_sz+(2 * NFS3_post_op_attr_sz)) > > > > >>>>>>>> #define NFS3_accessres_sz (1+NFS3_post_op_attr_sz+1) > > > > >>>>>>>> -#define NFS3_readlinkres_sz (1+NFS3_post_op_attr_sz+1) > > > > >>>>>>>> -#define NFS3_readres_sz (1+NFS3_post_op_attr_sz+3) > > > > >>>>>>>> +#define NFS3_readlinkres_sz (1+NFS3_post_op_attr_sz+1+1) > > > > >>>>>>>> +#define NFS3_readres_sz (1+NFS3_post_op_attr_sz+3+1) > > > > >>>>>>>> #define NFS3_writeres_sz (1+NFS3_wcc_data_sz+4) > > > > >>>>>>>> #define NFS3_createres_sz (1+NFS3_fh_sz+NFS3_post_op_attr_sz+NFS3_wcc_data_sz) > > > > >>>>>>>> #define NFS3_renameres_sz (1+(2 * NFS3_wcc_data_sz)) > > > > >>>>>>>> #define NFS3_linkres_sz (1+NFS3_post_op_attr_sz+NFS3_wcc_data_sz) > > > > >>>>>>>> -#define NFS3_readdirres_sz (1+NFS3_post_op_attr_sz+2) > > > > >>>>>>>> +#define NFS3_readdirres_sz (1+NFS3_post_op_attr_sz+2+1) > > > > >>>>>>>> #define NFS3_fsstatres_sz (1+NFS3_post_op_attr_sz+13) > > > > >>>>>>>> #define NFS3_fsinfores_sz (1+NFS3_post_op_attr_sz+12) > > > > >>>>>>>> #define NFS3_pathconfres_sz (1+NFS3_post_op_attr_sz+6) > > > > >>>>>>>> @@ -85,7 +85,7 @@ > > > > >>>>>>>> #define ACL3_setaclargs_sz (NFS3_fh_sz+1+ \ > > > > >>>>>>>> XDR_QUADLEN(NFS_ACL_INLINE_BUFSIZE)) > > > > >>>>>>>> #define ACL3_getaclres_sz (1+NFS3_post_op_attr_sz+1+ \ > > > > >>>>>>>> - XDR_QUADLEN(NFS_ACL_INLINE_BUFSIZE)) > > > > >>>>>>>> + XDR_QUADLEN(NFS_ACL_INLINE_BUFSIZE)+1) > > > > >>>>>>>> #define ACL3_setaclres_sz (1+NFS3_post_op_attr_sz) > > > > >>>>>>>> > > > > >>>>>>>> static int nfs3_stat_to_errno(enum nfs_stat); > > > > >>>>>>>> @@ -1629,7 +1629,7 @@ static int nfs3_xdr_dec_read3res(struct rpc_rqst *req, struct xdr_stream *xdr, > > > > >>>>>>>> result->op_status = status; > > > > >>>>>>>> if (status != NFS3_OK) > > > > >>>>>>>> goto out_status; > > > > >>>>>>>> - result->replen = 3 + ((xdr_stream_pos(xdr) - pos) >> 2); > > > > >>>>>>>> + result->replen = 4 + ((xdr_stream_pos(xdr) - pos) >> 2); > > > > >>>>>>>> error = decode_read3resok(xdr, result); > > > > >>>>>>>> out: > > > > >>>>>>>> return error; > > > > >>>>>>>> diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c > > > > >>>>>>>> index d0fa18d..6d9d5e2 100644 > > > > >>>>>>>> --- a/fs/nfs/nfs4xdr.c > > > > >>>>>>>> +++ b/fs/nfs/nfs4xdr.c > > > > >>>>>>>> @@ -215,14 +215,14 @@ static int decode_layoutget(struct xdr_stream *xdr, struct rpc_rqst *req, > > > > >>>>>>>> nfs4_fattr_bitmap_maxsz) > > > > >>>>>>>> #define encode_read_maxsz (op_encode_hdr_maxsz + \ > > > > >>>>>>>> encode_stateid_maxsz + 3) > > > > >>>>>>>> -#define decode_read_maxsz (op_decode_hdr_maxsz + 2) > > > > >>>>>>>> +#define decode_read_maxsz (op_decode_hdr_maxsz + 2 + 1) > > > > >>>>>>>> #define encode_readdir_maxsz (op_encode_hdr_maxsz + \ > > > > >>>>>>>> 2 + encode_verifier_maxsz + 5 + \ > > > > >>>>>>>> nfs4_label_maxsz) > > > > >>>>>>>> #define decode_readdir_maxsz (op_decode_hdr_maxsz + \ > > > > >>>>>>>> - decode_verifier_maxsz) > > > > >>>>>>>> + decode_verifier_maxsz + 1) > > > > >>>>>>>> #define encode_readlink_maxsz (op_encode_hdr_maxsz) > > > > >>>>>>>> -#define decode_readlink_maxsz (op_decode_hdr_maxsz + 1) > > > > >>>>>>>> +#define decode_readlink_maxsz (op_decode_hdr_maxsz + 1 + 1) > > > > >>>>>>>> #define encode_write_maxsz (op_encode_hdr_maxsz + \ > > > > >>>>>>>> encode_stateid_maxsz + 4) > > > > >>>>>>>> #define decode_write_maxsz (op_decode_hdr_maxsz + \ > > > > >>>>>>>> @@ -284,14 +284,14 @@ static int decode_layoutget(struct xdr_stream *xdr, struct rpc_rqst *req, > > > > >>>>>>>> #define decode_delegreturn_maxsz (op_decode_hdr_maxsz) > > > > >>>>>>>> #define encode_getacl_maxsz (encode_getattr_maxsz) > > > > >>>>>>>> #define decode_getacl_maxsz (op_decode_hdr_maxsz + \ > > > > >>>>>>>> - nfs4_fattr_bitmap_maxsz + 1) > > > > >>>>>>>> + nfs4_fattr_bitmap_maxsz + 1 + 1) > > > > >>>>>>>> #define encode_setacl_maxsz (op_encode_hdr_maxsz + \ > > > > >>>>>>>> encode_stateid_maxsz + 3) > > > > >>>>>>>> #define decode_setacl_maxsz (decode_setattr_maxsz) > > > > >>>>>>>> #define encode_fs_locations_maxsz \ > > > > >>>>>>>> (encode_getattr_maxsz) > > > > >>>>>>>> #define decode_fs_locations_maxsz \ > > > > >>>>>>>> - (0) > > > > >>>>>>>> + (1) > > > > >>>>>>>> #define encode_secinfo_maxsz (op_encode_hdr_maxsz + nfs4_name_maxsz) > > > > >>>>>>>> #define decode_secinfo_maxsz (op_decode_hdr_maxsz + 1 + ((NFS_MAX_SECFLAVORS * (16 + GSS_OID_MAX_LEN)) / 4)) > > > > >>>>>>>> > > > > >>>>>>>> @@ -392,12 +392,13 @@ static int decode_layoutget(struct xdr_stream *xdr, struct rpc_rqst *req, > > > > >>>>>>>> 1 /* opaque devaddr4 length */ + \ > > > > >>>>>>>> /* devaddr4 payload is read into page */ \ > > > > >>>>>>>> 1 /* notification bitmap length */ + \ > > > > >>>>>>>> - 1 /* notification bitmap, word 0 */) > > > > >>>>>>>> + 1 /* notification bitmap, word 0 */ + \ > > > > >>>>>>>> + 1 /* possible XDR padding */) > > > > >>>>>>>> #define encode_layoutget_maxsz (op_encode_hdr_maxsz + 10 + \ > > > > >>>>>>>> encode_stateid_maxsz) > > > > >>>>>>>> #define decode_layoutget_maxsz (op_decode_hdr_maxsz + 8 + \ > > > > >>>>>>>> decode_stateid_maxsz + \ > > > > >>>>>>>> - XDR_QUADLEN(PNFS_LAYOUT_MAXSIZE)) > > > > >>>>>>>> + XDR_QUADLEN(PNFS_LAYOUT_MAXSIZE) + 1) > > > > >>>>>>>> #define encode_layoutcommit_maxsz (op_encode_hdr_maxsz + \ > > > > >>>>>>>> 2 /* offset */ + \ > > > > >>>>>>>> 2 /* length */ + \ > > > > >>>>>>>> diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c > > > > >>>>>>>> index f780605..4ea38b0 100644 > > > > >>>>>>>> --- a/net/sunrpc/clnt.c > > > > >>>>>>>> +++ b/net/sunrpc/clnt.c > > > > >>>>>>>> @@ -1177,7 +1177,11 @@ void rpc_prepare_reply_pages(struct rpc_rqst *req, struct page **pages, > > > > >>>>>>>> unsigned int base, unsigned int len, > > > > >>>>>>>> unsigned int hdrsize) > > > > >>>>>>>> { > > > > >>>>>>>> - hdrsize += RPC_REPHDRSIZE + req->rq_cred->cr_auth->au_rslack; > > > > >>>>>>>> + /* Subtract one to force an extra word of buffer space for the > > > > >>>>>>>> + * payload's XDR pad to fall into the rcv_buf's tail iovec. > > > > >>>>>>>> + */ > > > > >>>>>>>> + hdrsize += RPC_REPHDRSIZE + req->rq_cred->cr_auth->au_rslack - 1; > > > > >>>>>>>> + > > > > >>>>>>>> xdr_inline_pages(&req->rq_rcv_buf, hdrsize << 2, pages, base, len); > > > > >>>>>>>> trace_rpc_reply_pages(req); > > > > >>>>>>>> } > > > > >>>>>>>> diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c > > > > >>>>>>>> index 7cca515..aa8177d 100644 > > > > >>>>>>>> --- a/net/sunrpc/xdr.c > > > > >>>>>>>> +++ b/net/sunrpc/xdr.c > > > > >>>>>>>> @@ -189,6 +189,8 @@ __be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int nbytes) > > > > >>>>>>>> > > > > >>>>>>>> tail->iov_base = buf + offset; > > > > >>>>>>>> tail->iov_len = buflen - offset; > > > > >>>>>>>> + if ((xdr->page_len & 3) == 0) > > > > >>>>>>>> + tail->iov_len -= sizeof(__be32); > > > > >>>>>>>> > > > > >>>>>>>> xdr->buflen += len; > > > > >>>>>>>> } > > > > >>>>>>>> > > > > >>>>>> > > > > >>>>>> -- > > > > >>>>>> Chuck Lever > > > > >>>> > > > > >>>> -- > > > > >>>> Chuck Lever > > > > >> > > > > >> -- > > > > >> Chuck Lever > > > > > > > > -- > > > > Chuck Lever > > > > > > > > > > > >