From 3fd9557aec919e2db99365ad5a2c00d04ae8893c Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Fri, 27 Jul 2018 11:19:05 -0400 Subject: [PATCH] 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 Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs3proc.c | 3 ++- fs/nfsd/nfs4proc.c | 23 ++++------------------- fs/nfsd/nfsproc.c | 3 ++- include/linux/sunrpc/svc.h | 1 + net/sunrpc/svc.c | 11 ++++------- 5 files changed, 13 insertions(+), 28 deletions(-) diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c index 6259a4b8579f..8d1c2d1a159b 100644 --- a/fs/nfsd/nfs3proc.c +++ b/fs/nfsd/nfs3proc.c @@ -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, diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c index 3652f9b1fb68..b7bc6e1a85ac 100644 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -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, diff --git a/fs/nfsd/nfsproc.c b/fs/nfsd/nfsproc.c index f107f9fa8e15..a6faee562b31 100644 --- a/fs/nfsd/nfsproc.c +++ b/fs/nfsd/nfsproc.c @@ -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), diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h index 574368e8a16f..43f88bd7b601 100644 --- a/include/linux/sunrpc/svc.h +++ b/include/linux/sunrpc/svc.h @@ -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); diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c index 30a4226baf03..2194ed507991 100644 --- a/net/sunrpc/svc.c +++ b/net/sunrpc/svc.c @@ -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; } -- 2.11.0