net/smc/smc_rx.c

Source file repositories/reference/linux-study-clean/net/smc/smc_rx.c

File Facts

System
Linux kernel
Corpus path
net/smc/smc_rx.c
Extension
.c
Size
14284 bytes
Lines
528
Domain
Networking Core
Bucket
Sockets, Protocols, Packet Path, And Network Policy
Inferred role
Networking Core: implementation source
Status
source implementation candidate

Why This File Exists

Networking stack implementation surface: socket APIs, protocol dispatch, packet flow, routing, filtering, and network namespaces.

Dependency Surface

Detected Declarations

Annotated Snippet

struct smc_spd_priv {
	struct smc_sock *smc;
	size_t		 len;
};

static void smc_rx_pipe_buf_release(struct pipe_inode_info *pipe,
				    struct pipe_buffer *buf)
{
	struct smc_spd_priv *priv = (struct smc_spd_priv *)buf->private;
	struct smc_sock *smc = priv->smc;
	struct smc_connection *conn;
	struct sock *sk = &smc->sk;

	if (sk->sk_state == SMC_CLOSED ||
	    sk->sk_state == SMC_PEERFINCLOSEWAIT ||
	    sk->sk_state == SMC_APPFINCLOSEWAIT)
		goto out;
	conn = &smc->conn;
	lock_sock(sk);
	smc_rx_update_cons(smc, priv->len);
	release_sock(sk);
	if (atomic_sub_and_test(priv->len, &conn->splice_pending))
		smc_rx_wake_up(sk);
out:
	kfree(priv);
	put_page(buf->page);
	sock_put(sk);
}

static bool smc_rx_pipe_buf_get(struct pipe_inode_info *pipe,
				struct pipe_buffer *buf)
{
	/* smc_spd_priv in buf->private is not shareable; disallow cloning. */
	return false;
}

static const struct pipe_buf_operations smc_pipe_ops = {
	.release = smc_rx_pipe_buf_release,
	.get	 = smc_rx_pipe_buf_get,
};

static void smc_rx_spd_release(struct splice_pipe_desc *spd,
			       unsigned int i)
{
	put_page(spd->pages[i]);
}

static int smc_rx_splice(struct pipe_inode_info *pipe, char *src, size_t len,
			 struct smc_sock *smc)
{
	struct smc_link_group *lgr = smc->conn.lgr;
	int offset = offset_in_page(src);
	struct partial_page *partial;
	struct splice_pipe_desc spd;
	struct smc_spd_priv **priv;
	struct page **pages;
	int bytes, nr_pages;
	int i;

	nr_pages = !lgr->is_smcd && smc->conn.rmb_desc->is_vm ?
		   PAGE_ALIGN(len + offset) / PAGE_SIZE : 1;

	pages = kzalloc_objs(*pages, nr_pages);
	if (!pages)
		goto out;
	partial = kzalloc_objs(*partial, nr_pages);
	if (!partial)
		goto out_page;
	priv = kzalloc_objs(*priv, nr_pages);
	if (!priv)
		goto out_part;
	for (i = 0; i < nr_pages; i++) {
		priv[i] = kzalloc_obj(**priv);
		if (!priv[i])
			goto out_priv;
	}

	if (lgr->is_smcd ||
	    (!lgr->is_smcd && !smc->conn.rmb_desc->is_vm)) {
		/* smcd or smcr that uses physically contiguous RMBs */
		priv[0]->len = len;
		priv[0]->smc = smc;
		partial[0].offset = src - (char *)smc->conn.rmb_desc->cpu_addr;
		partial[0].len = len;
		partial[0].private = (unsigned long)priv[0];
		pages[0] = smc->conn.rmb_desc->pages;
	} else {
		int size, left = len;
		void *buf = src;
		/* smcr that uses virtually contiguous RMBs*/

Annotation

Implementation Notes