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Commit 3fd9557a authored by Chuck Lever's avatar Chuck Lever Committed by J. Bruce Fields
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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: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
parent 07d0ff3b

fs/nfsd/nfs3proc.c

+2 −1
Original line number Diff line number Diff line
@@ -202,7 +202,8 @@ nfsd3_proc_write(struct svc_rqst *rqstp) 


	fh_copy(&resp->fh, &argp->fh);

	resp->committed = argp->stable;

	nvecs = svc_fill_write_vector(rqstp, &argp->first, cnt);

	nvecs = svc_fill_write_vector(rqstp, rqstp->rq_arg.pages,

				      &argp->first, cnt);

	if (!nvecs)

		RETURN_STATUS(nfserr_io);

	nfserr = nfsd_write(rqstp, &resp->fh, argp->offset,

fs/nfsd/nfs4proc.c

+4 −19
Original line number Diff line number Diff line
@@ -986,24 +986,6 @@ nfsd4_setattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, 
	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,

fs/nfsd/nfsproc.c

+2 −1
Original line number Diff line number Diff line
@@ -218,7 +218,8 @@ nfsd_proc_write(struct svc_rqst *rqstp) 
		SVCFH_fmt(&argp->fh),

		argp->len, argp->offset);



	nvecs = svc_fill_write_vector(rqstp, &argp->first, cnt);

	nvecs = svc_fill_write_vector(rqstp, rqstp->rq_arg.pages,

				      &argp->first, cnt);

	if (!nvecs)

		return nfserr_io;

	nfserr = nfsd_write(rqstp, fh_copy(&resp->fh, &argp->fh),

include/linux/sunrpc/svc.h

+1 −0
Original line number Diff line number Diff line
@@ -496,6 +496,7 @@ void svc_reserve(struct svc_rqst *rqstp, int space); 
struct svc_pool *  svc_pool_for_cpu(struct svc_serv *serv, int cpu);

char *		   svc_print_addr(struct svc_rqst *, char *, size_t);

unsigned int	   svc_fill_write_vector(struct svc_rqst *rqstp,

					 struct page **pages,

					 struct kvec *first, size_t total);

char		  *svc_fill_symlink_pathname(struct svc_rqst *rqstp,

					     struct kvec *first, size_t total);

net/sunrpc/svc.c

+4 −7
Original line number Diff line number Diff line
@@ -1537,16 +1537,16 @@ EXPORT_SYMBOL_GPL(svc_max_payload); 
/**

 * svc_fill_write_vector - Construct data argument for VFS write call

 * @rqstp: svc_rqst to operate on

 * @pages: list of pages containing data payload

 * @first: buffer containing first section of write payload

 * @total: total number of bytes of write payload

 *

 * Returns the number of elements populated in the data argument array.

 * Fills in rqstp::rq_vec, and returns the number of elements.

 */

unsigned int svc_fill_write_vector(struct svc_rqst *rqstp, struct kvec *first,

				   size_t total)

unsigned int svc_fill_write_vector(struct svc_rqst *rqstp, struct page **pages,

				   struct kvec *first, size_t total)

{

	struct kvec *vec = rqstp->rq_vec;

	struct page **pages;

	unsigned int i;



	/* Some types of transport can present the write payload
@@ -1560,14 +1560,11 @@ unsigned int svc_fill_write_vector(struct svc_rqst *rqstp, struct kvec *first, 
		++i;

	}



	WARN_ON_ONCE(rqstp->rq_arg.page_base != 0);

	pages = rqstp->rq_arg.pages;

	while (total) {

		vec[i].iov_base = page_address(*pages);

		vec[i].iov_len = min_t(size_t, total, PAGE_SIZE);

		total -= vec[i].iov_len;

		++i;



		++pages;

	}