From: Chuck Lever Date: Mon, 28 Apr 2025 19:36:54 +0000 (-0400) Subject: sunrpc: Replace the rq_bvec array with dynamically-allocated memory X-Git-Tag: v6.16-rc1~138^2~15 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=59cf7346542babdaae99e72365174eab4fa276ac;p=thirdparty%2Fkernel%2Fstable.git sunrpc: Replace the rq_bvec array with dynamically-allocated memory As a step towards making NFSD's maximum rsize and wsize variable at run-time, replace the fixed-size rq_bvec[] array in struct svc_rqst with a chunk of dynamically-allocated memory. The rq_bvec[] array contains enough bio_vecs to handle each page in a maximum size RPC message. On a system with 8-byte pointers and 4KB pages, pahole reports that the rq_bvec[] array is 4144 bytes. This patch replaces that array with a single 8-byte pointer field. Reviewed-by: Jeff Layton Reviewed-by: NeilBrown Signed-off-by: Chuck Lever --- diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h index 57be695398886..538bea716c6b1 100644 --- a/include/linux/sunrpc/svc.h +++ b/include/linux/sunrpc/svc.h @@ -213,7 +213,7 @@ struct svc_rqst { struct folio_batch rq_fbatch; struct kvec rq_vec[RPCSVC_MAXPAGES]; /* generally useful.. */ - struct bio_vec rq_bvec[RPCSVC_MAXPAGES]; + struct bio_vec *rq_bvec; __be32 rq_xid; /* transmission id */ u32 rq_prog; /* program number */ diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c index d320837e09f03..2c1c4aa93f43f 100644 --- a/net/sunrpc/svc.c +++ b/net/sunrpc/svc.c @@ -672,6 +672,7 @@ static void svc_rqst_free(struct svc_rqst *rqstp) { folio_batch_release(&rqstp->rq_fbatch); + kfree(rqstp->rq_bvec); svc_release_buffer(rqstp); if (rqstp->rq_scratch_page) put_page(rqstp->rq_scratch_page); @@ -710,6 +711,12 @@ svc_prepare_thread(struct svc_serv *serv, struct svc_pool *pool, int node) if (!svc_init_buffer(rqstp, serv, node)) goto out_enomem; + rqstp->rq_bvec = kcalloc_node(rqstp->rq_maxpages, + sizeof(struct bio_vec), + GFP_KERNEL, node); + if (!rqstp->rq_bvec) + goto out_enomem; + rqstp->rq_err = -EAGAIN; /* No error yet */ serv->sv_nrthreads += 1; diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c index 60f2883268faf..d9fdc6ae80205 100644 --- a/net/sunrpc/svcsock.c +++ b/net/sunrpc/svcsock.c @@ -713,8 +713,7 @@ static int svc_udp_sendto(struct svc_rqst *rqstp) if (svc_xprt_is_dead(xprt)) goto out_notconn; - count = xdr_buf_to_bvec(rqstp->rq_bvec, - ARRAY_SIZE(rqstp->rq_bvec), xdr); + count = xdr_buf_to_bvec(rqstp->rq_bvec, rqstp->rq_maxpages, xdr); iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, rqstp->rq_bvec, count, rqstp->rq_res.len); @@ -1219,8 +1218,8 @@ static int svc_tcp_sendmsg(struct svc_sock *svsk, struct svc_rqst *rqstp, memcpy(buf, &marker, sizeof(marker)); bvec_set_virt(rqstp->rq_bvec, buf, sizeof(marker)); - count = xdr_buf_to_bvec(rqstp->rq_bvec + 1, - ARRAY_SIZE(rqstp->rq_bvec) - 1, &rqstp->rq_res); + count = xdr_buf_to_bvec(rqstp->rq_bvec + 1, rqstp->rq_maxpages, + &rqstp->rq_res); iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, rqstp->rq_bvec, 1 + count, sizeof(marker) + rqstp->rq_res.len);