On Wed, 2020-12-09 at 11:16 -0500, Chuck Lever wrote: > Hey- > > > On Dec 9, 2020, at 9:48 AM, trondmy@xxxxxxxxxx wrote: > > > > From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> > > > > Ensure that we encode the data payload + padding, and that we > > truncate > > the preallocated buffer to the actual read size. > > Did you intend to merge 15/16 and 16/16 through your tree? No. They can go through the nfsd tree. I included them here because they are necessary in order to pass the xfstests. > Can the patch descriptions say a little more about why these > changes are necessary? If they fix a misbehavior, describe > the problem. It's the same problem and solution that exists in the READ code. nfsd_readv() doesn't necessarily return the same number of bytes that we requested and preallocated buffer space for. So to deal with that, we have to truncate the preallocated buffer. Finally, we have to write zeros into the padding bytes after the read buffer. > > Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> > > --- > > fs/nfsd/nfs4xdr.c | 5 +++++ > > 1 file changed, 5 insertions(+) > > > > diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c > > index 833a2c64dfe8..26f6e277101d 100644 > > --- a/fs/nfsd/nfs4xdr.c > > +++ b/fs/nfsd/nfs4xdr.c > > @@ -4632,6 +4632,7 @@ nfsd4_encode_read_plus_data(struct > > nfsd4_compoundres *resp, > > resp->rqstp->rq_vec, read->rd_vlen, > > maxcount, eof); > > if (nfserr) > > return nfserr; > > + xdr_truncate_encode(xdr, starting_len + 16 + > > xdr_align_size(*maxcount)); > > > > tmp = htonl(NFS4_CONTENT_DATA); > > write_bytes_to_xdr_buf(xdr->buf, starting_len, &tmp, > > 4); > > @@ -4639,6 +4640,10 @@ nfsd4_encode_read_plus_data(struct > > nfsd4_compoundres *resp, > > write_bytes_to_xdr_buf(xdr->buf, starting_len + 4, &tmp64, > > 8); > > tmp = htonl(*maxcount); > > write_bytes_to_xdr_buf(xdr->buf, starting_len + 12, &tmp, > > 4); > > + > > + tmp = xdr_zero; > > + write_bytes_to_xdr_buf(xdr->buf, starting_len + 16 + > > *maxcount, &tmp, > > + xdr_pad_size(*maxcount)); > > return nfs_ok; > > } -- Trond Myklebust Linux NFS client maintainer, Hammerspace trond.myklebust@xxxxxxxxxxxxxxx
