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Commit e053d1ab authored by Olaf Kirch's avatar Olaf Kirch Committed by Trond Myklebust
Browse files

[PATCH] RPC: Lazy RPC receive buffer allocation 



 Signed-off-by: default avatarOlaf Kirch <okir@suse.de>
 Signed-off-by: default avatarAndreas Gruenbacher <agruen@suse.de>
 Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent 007e251f

include/linux/sunrpc/xdr.h

+1 −1
Original line number Diff line number Diff line
@@ -160,7 +160,7 @@ typedef struct { 


typedef size_t (*skb_read_actor_t)(skb_reader_t *desc, void *to, size_t len);



extern void xdr_partial_copy_from_skb(struct xdr_buf *, unsigned int,

extern int xdr_partial_copy_from_skb(struct xdr_buf *, unsigned int,

		skb_reader_t *, skb_read_actor_t);



struct socket;

net/sunrpc/xdr.c

+13 −3
Original line number Diff line number Diff line
@@ -176,7 +176,7 @@ xdr_inline_pages(struct xdr_buf *xdr, unsigned int offset, 
	xdr->buflen += len;

}



void

int

xdr_partial_copy_from_skb(struct xdr_buf *xdr, unsigned int base,

			  skb_reader_t *desc,

			  skb_read_actor_t copy_actor)
@@ -190,7 +190,7 @@ xdr_partial_copy_from_skb(struct xdr_buf *xdr, unsigned int base, 
		len -= base;

		ret = copy_actor(desc, (char *)xdr->head[0].iov_base + base, len);

		if (ret != len || !desc->count)

			return;

			return 0;

		base = 0;

	} else

		base -= len;
@@ -210,6 +210,14 @@ xdr_partial_copy_from_skb(struct xdr_buf *xdr, unsigned int base, 
	do {

		char *kaddr;



		/* ACL likes to be lazy in allocating pages - ACLs

		 * are small by default but can get huge. */

		if (unlikely(*ppage == NULL)) {

			*ppage = alloc_page(GFP_ATOMIC);

			if (unlikely(*ppage == NULL))

				return -ENOMEM;

		}



		len = PAGE_CACHE_SIZE;

		kaddr = kmap_atomic(*ppage, KM_SKB_SUNRPC_DATA);

		if (base) {
@@ -226,13 +234,15 @@ xdr_partial_copy_from_skb(struct xdr_buf *xdr, unsigned int base, 
		flush_dcache_page(*ppage);

		kunmap_atomic(kaddr, KM_SKB_SUNRPC_DATA);

		if (ret != len || !desc->count)

			return;

			return 0;

		ppage++;

	} while ((pglen -= len) != 0);

copy_tail:

	len = xdr->tail[0].iov_len;

	if (base < len)

		copy_actor(desc, (char *)xdr->tail[0].iov_base + base, len - base);



	return 0;

}

net/sunrpc/xprt.c

+22 −4
Original line number Diff line number Diff line
@@ -725,7 +725,8 @@ csum_partial_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb) 
		goto no_checksum;



	desc.csum = csum_partial(skb->data, desc.offset, skb->csum);

	xdr_partial_copy_from_skb(xdr, 0, &desc, skb_read_and_csum_bits);

	if (xdr_partial_copy_from_skb(xdr, 0, &desc, skb_read_and_csum_bits) < 0)

		return -1;

	if (desc.offset != skb->len) {

		unsigned int csum2;

		csum2 = skb_checksum(skb, desc.offset, skb->len - desc.offset, 0);
@@ -737,7 +738,8 @@ csum_partial_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb) 
		return -1;

	return 0;

no_checksum:

	xdr_partial_copy_from_skb(xdr, 0, &desc, skb_read_bits);

	if (xdr_partial_copy_from_skb(xdr, 0, &desc, skb_read_bits) < 0)

		return -1;

	if (desc.count)

		return -1;

	return 0;
@@ -907,6 +909,7 @@ tcp_read_request(struct rpc_xprt *xprt, skb_reader_t *desc) 
	struct rpc_rqst *req;

	struct xdr_buf *rcvbuf;

	size_t len;

	int r;



	/* Find and lock the request corresponding to this xid */

	spin_lock(&xprt->sock_lock);
@@ -927,16 +930,30 @@ tcp_read_request(struct rpc_xprt *xprt, skb_reader_t *desc) 
		len = xprt->tcp_reclen - xprt->tcp_offset;

		memcpy(&my_desc, desc, sizeof(my_desc));

		my_desc.count = len;

		xdr_partial_copy_from_skb(rcvbuf, xprt->tcp_copied,

		r = xdr_partial_copy_from_skb(rcvbuf, xprt->tcp_copied,

					  &my_desc, tcp_copy_data);

		desc->count -= len;

		desc->offset += len;

	} else

		xdr_partial_copy_from_skb(rcvbuf, xprt->tcp_copied,

		r = xdr_partial_copy_from_skb(rcvbuf, xprt->tcp_copied,

					  desc, tcp_copy_data);

	xprt->tcp_copied += len;

	xprt->tcp_offset += len;



	if (r < 0) {

		/* Error when copying to the receive buffer,

		 * usually because we weren't able to allocate

		 * additional buffer pages. All we can do now

		 * is turn off XPRT_COPY_DATA, so the request

		 * will not receive any additional updates,

		 * and time out.

		 * Any remaining data from this record will

		 * be discarded.

		 */

		xprt->tcp_flags &= ~XPRT_COPY_DATA;

		goto out;

	}



	if (xprt->tcp_copied == req->rq_private_buf.buflen)

		xprt->tcp_flags &= ~XPRT_COPY_DATA;

	else if (xprt->tcp_offset == xprt->tcp_reclen) {
@@ -949,6 +966,7 @@ tcp_read_request(struct rpc_xprt *xprt, skb_reader_t *desc) 
				req->rq_task->tk_pid);

		xprt_complete_rqst(xprt, req, xprt->tcp_copied);

	}

out:

	spin_unlock(&xprt->sock_lock);

	tcp_check_recm(xprt);

}