> On Dec 3, 2020, at 3:18 PM, schumaker.anna@xxxxxxxxx wrote: > > From: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx> > > We might need this to better handle shifting around data in the reply > buffer. > > Suggested-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> > Signed-off-by: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx> > --- > fs/nfs/nfs42xdr.c | 2 ++ > fs/nfs/read.c | 13 +++++++++++-- > include/linux/nfs_xdr.h | 1 + > 3 files changed, 14 insertions(+), 2 deletions(-) > > diff --git a/fs/nfs/nfs42xdr.c b/fs/nfs/nfs42xdr.c > index 8432bd6b95f0..ef095a5f86f7 100644 > --- a/fs/nfs/nfs42xdr.c > +++ b/fs/nfs/nfs42xdr.c > @@ -1297,6 +1297,8 @@ static int nfs4_xdr_dec_read_plus(struct rpc_rqst *rqstp, > struct compound_hdr hdr; > int status; > > + xdr_set_scratch_buffer(xdr, page_address(res->scratch), PAGE_SIZE); I intend to submit this for v5.11: https://git.linux-nfs.org/?p=cel/cel-2.6.git;a=commit;h=0ae4c3e8a64ace1b8d7de033b0751afe43024416 But seems like enough callers need a scratch buffer that the XDR layer should set up it transparently for all requests. > + > status = decode_compound_hdr(xdr, &hdr); > if (status) > goto out; > diff --git a/fs/nfs/read.c b/fs/nfs/read.c > index eb854f1f86e2..012deb5a136f 100644 > --- a/fs/nfs/read.c > +++ b/fs/nfs/read.c > @@ -37,15 +37,24 @@ static struct kmem_cache *nfs_rdata_cachep; > > static struct nfs_pgio_header *nfs_readhdr_alloc(void) > { > - struct nfs_pgio_header *p = kmem_cache_zalloc(nfs_rdata_cachep, GFP_KERNEL); > + struct nfs_pgio_header *p; > + struct page *page; > > - if (p) > + page = alloc_page(GFP_KERNEL); > + if (!page) > + return ERR_PTR(-ENOMEM); > + > + p = kmem_cache_zalloc(nfs_rdata_cachep, GFP_KERNEL); > + if (p) { > p->rw_mode = FMODE_READ; > + p->res.scratch = page; > + } > return p; > } > > static void nfs_readhdr_free(struct nfs_pgio_header *rhdr) > { > + __free_page(rhdr->res.scratch); > kmem_cache_free(nfs_rdata_cachep, rhdr); > } > > diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h > index d63cb862d58e..e0a1c97f11a9 100644 > --- a/include/linux/nfs_xdr.h > +++ b/include/linux/nfs_xdr.h > @@ -659,6 +659,7 @@ struct nfs_pgio_res { > struct nfs_fattr * fattr; > __u64 count; > __u32 op_status; > + struct page * scratch; > union { > struct { > unsigned int replen; /* used by read */ > -- > 2.29.2 > -- Chuck Lever
