[PATCH RFC 3/6] NFSD: Have legacy NFSD WRITE decoders use xdr_stream_subsegment()
From: Chuck Lever <chuck.lever@oracle.com>
Date: 2021-08-31 19:05:30
Also in:
linux-nfs
Subsystem:
filesystems (vfs and infrastructure), kernel nfsd, sunrpc, and lockd servers, networking [general], nfs, sunrpc, and lockd clients, the rest · Maintainers:
Alexander Viro, Christian Brauner, Chuck Lever, Jeff Layton, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Trond Myklebust, Anna Schumaker, Linus Torvalds
Refactor. Now that the NFSv2 and NFSv3 XDR decoders have been converted to use xdr_streams, the WRITE decoder functions can use xdr_stream_subsegment() to extract the WRITE payload into its own xdr_buf, just as the NFSv4 WRITE XDR decoder currently does. That makes it possible to pass the first kvec, pages array + length, page_base, and total payload length via a single function parameter. The payload's page_base is not yet assigned or used, but will be in subsequent patches. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> --- fs/nfsd/nfs3proc.c | 3 +-- fs/nfsd/nfs3xdr.c | 12 ++---------- fs/nfsd/nfs4proc.c | 3 +-- fs/nfsd/nfsproc.c | 3 +-- fs/nfsd/nfsxdr.c | 9 +-------- fs/nfsd/xdr.h | 2 +- fs/nfsd/xdr3.h | 2 +- include/linux/sunrpc/svc.h | 3 +-- net/sunrpc/svc.c | 11 ++++++----- 9 files changed, 15 insertions(+), 33 deletions(-)
diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c
index 17715a6c7a40..4418517f6f12 100644
--- a/fs/nfsd/nfs3proc.c
+++ b/fs/nfsd/nfs3proc.c@@ -201,8 +201,7 @@ nfsd3_proc_write(struct svc_rqst *rqstp) fh_copy(&resp->fh, &argp->fh); resp->committed = argp->stable; - nvecs = svc_fill_write_vector(rqstp, rqstp->rq_arg.pages, - &argp->first, cnt); + nvecs = svc_fill_write_vector(rqstp, &argp->payload); if (!nvecs) { resp->status = nfserr_io; goto out;
diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c
index 0a5ebc52e6a9..91d4e2b8b854 100644
--- a/fs/nfsd/nfs3xdr.c
+++ b/fs/nfsd/nfs3xdr.c@@ -621,9 +621,6 @@ nfs3svc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p) struct xdr_stream *xdr = &rqstp->rq_arg_stream; struct nfsd3_writeargs *args = rqstp->rq_argp; u32 max_blocksize = svc_max_payload(rqstp); - struct kvec *head = rqstp->rq_arg.head; - struct kvec *tail = rqstp->rq_arg.tail; - size_t remaining; if (!svcxdr_decode_nfs_fh3(xdr, &args->fh)) return 0;
@@ -641,17 +638,12 @@ nfs3svc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p) /* request sanity */ if (args->count != args->len) return 0; - remaining = head->iov_len + rqstp->rq_arg.page_len + tail->iov_len; - remaining -= xdr_stream_pos(xdr); - if (remaining < xdr_align_size(args->len)) - return 0; if (args->count > max_blocksize) { args->count = max_blocksize; args->len = max_blocksize; } - - args->first.iov_base = xdr->p; - args->first.iov_len = head->iov_len - xdr_stream_pos(xdr); + if (!xdr_stream_subsegment(xdr, &args->payload, args->count)) + return 0; return 1; }
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 486c5dba4b65..55c9551fa74e 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c@@ -1033,8 +1033,7 @@ nfsd4_write(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, write->wr_how_written = write->wr_stable_how; - nvecs = svc_fill_write_vector(rqstp, write->wr_payload.pages, - write->wr_payload.head, write->wr_buflen); + nvecs = svc_fill_write_vector(rqstp, &write->wr_payload); WARN_ON_ONCE(nvecs > ARRAY_SIZE(rqstp->rq_vec)); status = nfsd_vfs_write(rqstp, &cstate->current_fh, nf,
diff --git a/fs/nfsd/nfsproc.c b/fs/nfsd/nfsproc.c
index 90fcd6178823..eea5b59b6a6c 100644
--- a/fs/nfsd/nfsproc.c
+++ b/fs/nfsd/nfsproc.c@@ -234,8 +234,7 @@ nfsd_proc_write(struct svc_rqst *rqstp) SVCFH_fmt(&argp->fh), argp->len, argp->offset); - nvecs = svc_fill_write_vector(rqstp, rqstp->rq_arg.pages, - &argp->first, cnt); + nvecs = svc_fill_write_vector(rqstp, &argp->payload); if (!nvecs) { resp->status = nfserr_io; goto out;
diff --git a/fs/nfsd/nfsxdr.c b/fs/nfsd/nfsxdr.c
index a06c05fe3b42..26a42f87c240 100644
--- a/fs/nfsd/nfsxdr.c
+++ b/fs/nfsd/nfsxdr.c@@ -325,10 +325,7 @@ nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p) { struct xdr_stream *xdr = &rqstp->rq_arg_stream; struct nfsd_writeargs *args = rqstp->rq_argp; - struct kvec *head = rqstp->rq_arg.head; - struct kvec *tail = rqstp->rq_arg.tail; u32 beginoffset, totalcount; - size_t remaining; if (!svcxdr_decode_fhandle(xdr, &args->fh)) return 0;
@@ -346,12 +343,8 @@ nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p) return 0; if (args->len > NFSSVC_MAXBLKSIZE_V2) return 0; - remaining = head->iov_len + rqstp->rq_arg.page_len + tail->iov_len; - remaining -= xdr_stream_pos(xdr); - if (remaining < xdr_align_size(args->len)) + if (!xdr_stream_subsegment(xdr, &args->payload, args->len)) return 0; - args->first.iov_base = xdr->p; - args->first.iov_len = head->iov_len - xdr_stream_pos(xdr); return 1; }
diff --git a/fs/nfsd/xdr.h b/fs/nfsd/xdr.h
index f45b4bc93f52..80fd6d7f3404 100644
--- a/fs/nfsd/xdr.h
+++ b/fs/nfsd/xdr.h@@ -33,7 +33,7 @@ struct nfsd_writeargs { svc_fh fh; __u32 offset; int len; - struct kvec first; + struct xdr_buf payload; }; struct nfsd_createargs {
diff --git a/fs/nfsd/xdr3.h b/fs/nfsd/xdr3.h
index 933008382bbe..712c117300cb 100644
--- a/fs/nfsd/xdr3.h
+++ b/fs/nfsd/xdr3.h@@ -40,7 +40,7 @@ struct nfsd3_writeargs { __u32 count; int stable; __u32 len; - struct kvec first; + struct xdr_buf payload; }; struct nfsd3_createargs {
diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
index f0f846fa396e..5a277acf2667 100644
--- a/include/linux/sunrpc/svc.h
+++ b/include/linux/sunrpc/svc.h@@ -532,8 +532,7 @@ int svc_encode_result_payload(struct svc_rqst *rqstp, unsigned int offset, unsigned int length); unsigned int svc_fill_write_vector(struct svc_rqst *rqstp, - struct page **pages, - struct kvec *first, size_t total); + struct xdr_buf *payload); char *svc_fill_symlink_pathname(struct svc_rqst *rqstp, struct kvec *first, void *p, size_t total);
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index bfcbaf7b3822..34ced7f538ee 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c@@ -1693,16 +1693,17 @@ EXPORT_SYMBOL_GPL(svc_encode_result_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 + * @payload: xdr_buf containing only the write data payload * * Fills in rqstp::rq_vec, and returns the number of elements. */ -unsigned int svc_fill_write_vector(struct svc_rqst *rqstp, struct page **pages, - struct kvec *first, size_t total) +unsigned int svc_fill_write_vector(struct svc_rqst *rqstp, + struct xdr_buf *payload) { + struct page **pages = payload->pages; + struct kvec *first = payload->head; struct kvec *vec = rqstp->rq_vec; + size_t total = payload->len; unsigned int i; /* Some types of transport can present the write payload