Re: [PATCH] nfsd: allow nfsv3 readdir request to be larger.

From: J. Bruce Fields
Date: Fri Mar 08 2019 - 14:29:50 EST


Thanks! Applied.

On Thu, Mar 07, 2019 at 09:49:46AM +1100, NeilBrown wrote:
>
> nfsd currently reports the NFSv4 dtpref FSINFO parameter

(Just changed NFSv4 here to NFSv3.)--b.

> to be PAGE_SIZE, so NFS clients will typically ask for one
> page of directory entries at a time. This is needlessly restrictive
> as nfsd can handle larger replies easily.
>
> Also, a READDIR request (but not a READDIRPLUS request) has the count
> size clipped to PAGE_SIE, again unnecessary.
>
> This patch lifts these limits so that larger readdir requests can be
> used.
>
> Signed-off-by: NeilBrown <neilb@xxxxxxxx>
> ---
> fs/nfsd/nfs3proc.c | 2 +-
> fs/nfsd/nfs3xdr.c | 4 +++-
> 2 files changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c
> index c9cf46e0c040..8f933e84cec1 100644
> --- a/fs/nfsd/nfs3proc.c
> +++ b/fs/nfsd/nfs3proc.c
> @@ -588,7 +588,7 @@ nfsd3_proc_fsinfo(struct svc_rqst *rqstp)
> resp->f_wtmax = max_blocksize;
> resp->f_wtpref = max_blocksize;
> resp->f_wtmult = PAGE_SIZE;
> - resp->f_dtpref = PAGE_SIZE;
> + resp->f_dtpref = max_blocksize;
> resp->f_maxfilesize = ~(u32) 0;
> resp->f_properties = NFS3_FSF_DEFAULT;
>
> diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c
> index 83919116d5cb..93fea246f676 100644
> --- a/fs/nfsd/nfs3xdr.c
> +++ b/fs/nfsd/nfs3xdr.c
> @@ -573,6 +573,8 @@ int
> nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p)
> {
> struct nfsd3_readdirargs *args = rqstp->rq_argp;
> + u32 max_blocksize = svc_max_payload(rqstp);
> +
> p = decode_fh(p, &args->fh);
> if (!p)
> return 0;
> @@ -580,7 +582,7 @@ nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p)
> args->verf = p; p += 2;
> args->dircount = ~0;
> args->count = ntohl(*p++);
> - args->count = min_t(u32, args->count, PAGE_SIZE);
> + args->count = min_t(u32, args->count, max_blocksize);
> args->buffer = page_address(*(rqstp->rq_next_page++));
>
> return xdr_argsize_check(rqstp, p);
> --
> 2.14.0.rc0.dirty
>