NFSD: Refactor the generic write vector fill helper

fill_in_write_vector() is nearly the same logic as
svc_fill_write_vector(), but there are a few differences so that
the former can handle multiple WRITE payloads in a single COMPOUND.

svc_fill_write_vector() can be adjusted so that it can be used in
the NFSv4 WRITE code path too. Instead of assuming the pages are
coming from rq_args.pages, have the caller pass in the page list.

The immediate benefit is a reduction of code duplication. It also
prevents the NFSv4 WRITE decoder from passing an empty vector
element when the transport has provided the payload in the xdr_buf's
page array.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This commit is contained in:
Chuck Lever
2018-07-27 11:19:05 -04:00
committed by J. Bruce Fields
parent 07d0ff3b0c
commit 3fd9557aec
5 changed files with 13 additions and 28 deletions

View File

@@ -986,24 +986,6 @@ out:
return status;
}
static int fill_in_write_vector(struct kvec *vec, struct nfsd4_write *write)
{
int i = 1;
int buflen = write->wr_buflen;
vec[0].iov_base = write->wr_head.iov_base;
vec[0].iov_len = min_t(int, buflen, write->wr_head.iov_len);
buflen -= vec[0].iov_len;
while (buflen) {
vec[i].iov_base = page_address(write->wr_pagelist[i - 1]);
vec[i].iov_len = min_t(int, PAGE_SIZE, buflen);
buflen -= vec[i].iov_len;
i++;
}
return i;
}
static __be32
nfsd4_write(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
union nfsd4_op_u *u)
@@ -1031,7 +1013,10 @@ nfsd4_write(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
write->wr_how_written = write->wr_stable_how;
gen_boot_verifier(&write->wr_verifier, SVC_NET(rqstp));
nvecs = fill_in_write_vector(rqstp->rq_vec, write);
nvecs = svc_fill_write_vector(rqstp, write->wr_pagelist,
&write->wr_head, write->wr_buflen);
if (!nvecs)
return nfserr_io;
WARN_ON_ONCE(nvecs > ARRAY_SIZE(rqstp->rq_vec));
status = nfsd_vfs_write(rqstp, &cstate->current_fh, filp,