On Mon, Mar 01, 2021 at 10:16:31AM -0500, Chuck Lever wrote:
> Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
> ---
> fs/nfsd/nfs3xdr.c | 58 ++++++++++++++++++++++++++++++++++++++++-------------
> 1 file changed, 44 insertions(+), 14 deletions(-)
>
> diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c
> index e159e4557428..e4a569e7216d 100644
> --- a/fs/nfsd/nfs3xdr.c
> +++ b/fs/nfsd/nfs3xdr.c
> @@ -17,6 +17,13 @@
> #define NFSDDBG_FACILITY NFSDDBG_XDR
>
>
> +/*
> + * Force construction of an empty post-op attr
> + */
> +static const struct svc_fh nfs3svc_null_fh = {
> + .fh_no_wcc = true,
> +};
> +
> /*
> * Mapping of S_IF* types to NFS file types
> */
> @@ -1392,27 +1399,50 @@ nfs3svc_encode_entry_plus(void *cd, const char *name,
> return encode_entry(cd, name, namlen, offset, ino, d_type, 1);
> }
>
> +static bool
> +svcxdr_encode_fsstat3resok(struct xdr_stream *xdr,
> + const struct nfsd3_fsstatres *resp)
> +{
> + const struct kstatfs *s = &resp->stats;
> + u64 bs = s->f_bsize;
> + __be32 *p;
> +
> + p = xdr_reserve_space(xdr, XDR_UNIT * 13);
> + if (!p)
> + return false;
> + p = xdr_encode_hyper(p, bs * s->f_blocks); /* total bytes */
> + p = xdr_encode_hyper(p, bs * s->f_bfree); /* free bytes */
> + p = xdr_encode_hyper(p, bs * s->f_bavail); /* user available bytes */
> + p = xdr_encode_hyper(p, s->f_files); /* total inodes */
> + p = xdr_encode_hyper(p, s->f_ffree); /* free inodes */
> + p = xdr_encode_hyper(p, s->f_ffree); /* user available inodes */
> + *p = cpu_to_be32(resp->invarsec); /* mean unchanged time */
> +
> + return true;
> +}
> +
> /* FSSTAT */
> int
> nfs3svc_encode_fsstatres(struct svc_rqst *rqstp, __be32 *p)
> {
> + struct xdr_stream *xdr = &rqstp->rq_res_stream;
> struct nfsd3_fsstatres *resp = rqstp->rq_resp;
> - struct kstatfs *s = &resp->stats;
> - u64 bs = s->f_bsize;
>
> - *p++ = resp->status;
> - *p++ = xdr_zero; /* no post_op_attr */
> -
> - if (resp->status == 0) {
> - p = xdr_encode_hyper(p, bs * s->f_blocks); /* total bytes */
> - p = xdr_encode_hyper(p, bs * s->f_bfree); /* free bytes */
> - p = xdr_encode_hyper(p, bs * s->f_bavail); /* user available bytes */
> - p = xdr_encode_hyper(p, s->f_files); /* total inodes */
> - p = xdr_encode_hyper(p, s->f_ffree); /* free inodes */
> - p = xdr_encode_hyper(p, s->f_ffree); /* user available inodes */
> - *p++ = htonl(resp->invarsec); /* mean unchanged time */
> + if (!svcxdr_encode_nfsstat3(xdr, resp->status))
> + return 0;
> + switch (resp->status) {
> + case nfs_ok:
> + if (!svcxdr_encode_post_op_attr(rqstp, xdr, &nfs3svc_null_fh))
> + return 0;
> + if (!svcxdr_encode_fsstat3resok(xdr, resp))
> + return 0;
> + break;
> + default:
> + if (!svcxdr_encode_post_op_attr(rqstp, xdr, &nfs3svc_null_fh))
> + return 0;
Dumb question: will this result in the same xdr on the wire as the above
that just hard-coded xdr_zero?
I feel like there's a lot of biolerplate error handling. In the v4 case
I centralized some of it after a fuzzer found an oops in some of that
copy-pasted boilerplate:
b7571e4cd39a nfsd4: skip encoder in trivial error cases
bac966d60652 nfsd4: individual encoders no longer see error cases
I dunno, maybe that was overkill.
--b.
> }
> - return xdr_ressize_check(rqstp, p);
> +
> + return 1;
> }
>
> /* FSINFO */
>
