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![Trond Myklebust](/assets/img/avatar_default.png)
Make sure that rpciod and xprtiod are always using the same slab allocation modes. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
330 lines
7.9 KiB
C
330 lines
7.9 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* linux/net/sunrpc/socklib.c
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*
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* Common socket helper routines for RPC client and server
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*
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* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
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*/
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#include <linux/compiler.h>
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#include <linux/netdevice.h>
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#include <linux/gfp.h>
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#include <linux/skbuff.h>
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#include <linux/types.h>
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#include <linux/pagemap.h>
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#include <linux/udp.h>
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#include <linux/sunrpc/msg_prot.h>
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#include <linux/sunrpc/sched.h>
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#include <linux/sunrpc/xdr.h>
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#include <linux/export.h>
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#include "socklib.h"
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/*
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* Helper structure for copying from an sk_buff.
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*/
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struct xdr_skb_reader {
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struct sk_buff *skb;
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unsigned int offset;
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size_t count;
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__wsum csum;
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};
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typedef size_t (*xdr_skb_read_actor)(struct xdr_skb_reader *desc, void *to,
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size_t len);
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/**
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* xdr_skb_read_bits - copy some data bits from skb to internal buffer
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* @desc: sk_buff copy helper
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* @to: copy destination
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* @len: number of bytes to copy
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*
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* Possibly called several times to iterate over an sk_buff and copy
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* data out of it.
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*/
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static size_t
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xdr_skb_read_bits(struct xdr_skb_reader *desc, void *to, size_t len)
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{
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if (len > desc->count)
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len = desc->count;
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if (unlikely(skb_copy_bits(desc->skb, desc->offset, to, len)))
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return 0;
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desc->count -= len;
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desc->offset += len;
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return len;
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}
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/**
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* xdr_skb_read_and_csum_bits - copy and checksum from skb to buffer
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* @desc: sk_buff copy helper
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* @to: copy destination
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* @len: number of bytes to copy
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*
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* Same as skb_read_bits, but calculate a checksum at the same time.
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*/
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static size_t xdr_skb_read_and_csum_bits(struct xdr_skb_reader *desc, void *to, size_t len)
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{
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unsigned int pos;
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__wsum csum2;
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if (len > desc->count)
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len = desc->count;
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pos = desc->offset;
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csum2 = skb_copy_and_csum_bits(desc->skb, pos, to, len);
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desc->csum = csum_block_add(desc->csum, csum2, pos);
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desc->count -= len;
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desc->offset += len;
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return len;
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}
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/**
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* xdr_partial_copy_from_skb - copy data out of an skb
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* @xdr: target XDR buffer
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* @base: starting offset
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* @desc: sk_buff copy helper
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* @copy_actor: virtual method for copying data
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*
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*/
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static ssize_t
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xdr_partial_copy_from_skb(struct xdr_buf *xdr, unsigned int base, struct xdr_skb_reader *desc, xdr_skb_read_actor copy_actor)
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{
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struct page **ppage = xdr->pages;
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unsigned int len, pglen = xdr->page_len;
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ssize_t copied = 0;
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size_t ret;
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len = xdr->head[0].iov_len;
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if (base < len) {
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len -= base;
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ret = copy_actor(desc, (char *)xdr->head[0].iov_base + base, len);
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copied += ret;
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if (ret != len || !desc->count)
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goto out;
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base = 0;
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} else
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base -= len;
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if (unlikely(pglen == 0))
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goto copy_tail;
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if (unlikely(base >= pglen)) {
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base -= pglen;
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goto copy_tail;
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}
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if (base || xdr->page_base) {
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pglen -= base;
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base += xdr->page_base;
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ppage += base >> PAGE_SHIFT;
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base &= ~PAGE_MASK;
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}
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do {
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char *kaddr;
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/* ACL likes to be lazy in allocating pages - ACLs
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* are small by default but can get huge. */
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if ((xdr->flags & XDRBUF_SPARSE_PAGES) && *ppage == NULL) {
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*ppage = alloc_page(GFP_NOWAIT | __GFP_NOWARN);
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if (unlikely(*ppage == NULL)) {
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if (copied == 0)
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copied = -ENOMEM;
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goto out;
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}
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}
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len = PAGE_SIZE;
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kaddr = kmap_atomic(*ppage);
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if (base) {
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len -= base;
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if (pglen < len)
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len = pglen;
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ret = copy_actor(desc, kaddr + base, len);
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base = 0;
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} else {
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if (pglen < len)
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len = pglen;
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ret = copy_actor(desc, kaddr, len);
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}
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flush_dcache_page(*ppage);
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kunmap_atomic(kaddr);
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copied += ret;
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if (ret != len || !desc->count)
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goto out;
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ppage++;
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} while ((pglen -= len) != 0);
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copy_tail:
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len = xdr->tail[0].iov_len;
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if (base < len)
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copied += copy_actor(desc, (char *)xdr->tail[0].iov_base + base, len - base);
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out:
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return copied;
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}
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/**
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* csum_partial_copy_to_xdr - checksum and copy data
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* @xdr: target XDR buffer
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* @skb: source skb
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*
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* We have set things up such that we perform the checksum of the UDP
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* packet in parallel with the copies into the RPC client iovec. -DaveM
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*/
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int csum_partial_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb)
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{
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struct xdr_skb_reader desc;
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desc.skb = skb;
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desc.offset = 0;
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desc.count = skb->len - desc.offset;
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if (skb_csum_unnecessary(skb))
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goto no_checksum;
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desc.csum = csum_partial(skb->data, desc.offset, skb->csum);
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if (xdr_partial_copy_from_skb(xdr, 0, &desc, xdr_skb_read_and_csum_bits) < 0)
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return -1;
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if (desc.offset != skb->len) {
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__wsum csum2;
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csum2 = skb_checksum(skb, desc.offset, skb->len - desc.offset, 0);
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desc.csum = csum_block_add(desc.csum, csum2, desc.offset);
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}
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if (desc.count)
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return -1;
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if (csum_fold(desc.csum))
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return -1;
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if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE) &&
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!skb->csum_complete_sw)
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netdev_rx_csum_fault(skb->dev, skb);
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return 0;
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no_checksum:
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if (xdr_partial_copy_from_skb(xdr, 0, &desc, xdr_skb_read_bits) < 0)
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return -1;
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if (desc.count)
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return -1;
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return 0;
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}
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EXPORT_SYMBOL_GPL(csum_partial_copy_to_xdr);
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static inline int xprt_sendmsg(struct socket *sock, struct msghdr *msg,
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size_t seek)
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{
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if (seek)
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iov_iter_advance(&msg->msg_iter, seek);
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return sock_sendmsg(sock, msg);
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}
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static int xprt_send_kvec(struct socket *sock, struct msghdr *msg,
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struct kvec *vec, size_t seek)
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{
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iov_iter_kvec(&msg->msg_iter, WRITE, vec, 1, vec->iov_len);
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return xprt_sendmsg(sock, msg, seek);
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}
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static int xprt_send_pagedata(struct socket *sock, struct msghdr *msg,
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struct xdr_buf *xdr, size_t base)
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{
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int err;
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err = xdr_alloc_bvec(xdr, rpc_task_gfp_mask());
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if (err < 0)
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return err;
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iov_iter_bvec(&msg->msg_iter, WRITE, xdr->bvec, xdr_buf_pagecount(xdr),
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xdr->page_len + xdr->page_base);
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return xprt_sendmsg(sock, msg, base + xdr->page_base);
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}
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/* Common case:
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* - stream transport
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* - sending from byte 0 of the message
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* - the message is wholly contained in @xdr's head iovec
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*/
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static int xprt_send_rm_and_kvec(struct socket *sock, struct msghdr *msg,
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rpc_fraghdr marker, struct kvec *vec,
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size_t base)
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{
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struct kvec iov[2] = {
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[0] = {
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.iov_base = &marker,
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.iov_len = sizeof(marker)
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},
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[1] = *vec,
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};
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size_t len = iov[0].iov_len + iov[1].iov_len;
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iov_iter_kvec(&msg->msg_iter, WRITE, iov, 2, len);
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return xprt_sendmsg(sock, msg, base);
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}
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/**
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* xprt_sock_sendmsg - write an xdr_buf directly to a socket
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* @sock: open socket to send on
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* @msg: socket message metadata
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* @xdr: xdr_buf containing this request
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* @base: starting position in the buffer
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* @marker: stream record marker field
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* @sent_p: return the total number of bytes successfully queued for sending
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*
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* Return values:
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* On success, returns zero and fills in @sent_p.
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* %-ENOTSOCK if @sock is not a struct socket.
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*/
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int xprt_sock_sendmsg(struct socket *sock, struct msghdr *msg,
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struct xdr_buf *xdr, unsigned int base,
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rpc_fraghdr marker, unsigned int *sent_p)
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{
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unsigned int rmsize = marker ? sizeof(marker) : 0;
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unsigned int remainder = rmsize + xdr->len - base;
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unsigned int want;
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int err = 0;
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*sent_p = 0;
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if (unlikely(!sock))
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return -ENOTSOCK;
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msg->msg_flags |= MSG_MORE;
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want = xdr->head[0].iov_len + rmsize;
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if (base < want) {
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unsigned int len = want - base;
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remainder -= len;
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if (remainder == 0)
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msg->msg_flags &= ~MSG_MORE;
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if (rmsize)
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err = xprt_send_rm_and_kvec(sock, msg, marker,
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&xdr->head[0], base);
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else
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err = xprt_send_kvec(sock, msg, &xdr->head[0], base);
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if (remainder == 0 || err != len)
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goto out;
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*sent_p += err;
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base = 0;
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} else {
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base -= want;
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}
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if (base < xdr->page_len) {
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unsigned int len = xdr->page_len - base;
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remainder -= len;
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if (remainder == 0)
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msg->msg_flags &= ~MSG_MORE;
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err = xprt_send_pagedata(sock, msg, xdr, base);
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if (remainder == 0 || err != len)
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goto out;
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*sent_p += err;
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base = 0;
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} else {
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base -= xdr->page_len;
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}
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if (base >= xdr->tail[0].iov_len)
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return 0;
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msg->msg_flags &= ~MSG_MORE;
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err = xprt_send_kvec(sock, msg, &xdr->tail[0], base);
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out:
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if (err > 0) {
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*sent_p += err;
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err = 0;
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}
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return err;
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}
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