> On Apr 5, 2019, at 1:36 PM, Olga Kornievskaia <aglo@xxxxxxxxx> 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.
> On Mon, Feb 11, 2019 at 11:25 AM Chuck Lever <chuck.lever@xxxxxxxxxx> 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 <chuck.lever@xxxxxxxxxx>
>> ---
>> 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
