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33 #include <linux/kernel.h>
34 #include <linux/slab.h>
40 static struct kmem_cache *rds_tcp_incoming_slab;
42 static void rds_tcp_inc_purge(struct rds_incoming *inc)
44 struct rds_tcp_incoming *tinc;
45 tinc = container_of(inc, struct rds_tcp_incoming, ti_inc);
46 rdsdebug("purging tinc %p inc %p\n", tinc, inc);
47 skb_queue_purge(&tinc->ti_skb_list);
50 void rds_tcp_inc_free(struct rds_incoming *inc)
52 struct rds_tcp_incoming *tinc;
53 tinc = container_of(inc, struct rds_tcp_incoming, ti_inc);
54 rds_tcp_inc_purge(inc);
55 rdsdebug("freeing tinc %p inc %p\n", tinc, inc);
56 kmem_cache_free(rds_tcp_incoming_slab, tinc);
60 * this is pretty lame, but, whatever.
62 int rds_tcp_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to)
64 struct rds_tcp_incoming *tinc;
68 if (!iov_iter_count(to))
71 tinc = container_of(inc, struct rds_tcp_incoming, ti_inc);
73 skb_queue_walk(&tinc->ti_skb_list, skb) {
74 unsigned long to_copy, skb_off;
75 for (skb_off = 0; skb_off < skb->len; skb_off += to_copy) {
76 to_copy = iov_iter_count(to);
77 to_copy = min(to_copy, skb->len - skb_off);
79 if (skb_copy_datagram_iter(skb, skb_off, to, to_copy))
82 rds_stats_add(s_copy_to_user, to_copy);
85 if (!iov_iter_count(to))
94 * We have a series of skbs that have fragmented pieces of the congestion
95 * bitmap. They must add up to the exact size of the congestion bitmap. We
96 * use the skb helpers to copy those into the pages that make up the in-memory
97 * congestion bitmap for the remote address of this connection. We then tell
98 * the congestion core that the bitmap has been changed so that it can wake up
101 * This is racing with sending paths which are using test_bit to see if the
102 * bitmap indicates that their recipient is congested.
105 static void rds_tcp_cong_recv(struct rds_connection *conn,
106 struct rds_tcp_incoming *tinc)
109 unsigned int to_copy, skb_off;
110 unsigned int map_off;
111 unsigned int map_page;
112 struct rds_cong_map *map;
115 /* catch completely corrupt packets */
116 if (be32_to_cpu(tinc->ti_inc.i_hdr.h_len) != RDS_CONG_MAP_BYTES)
123 skb_queue_walk(&tinc->ti_skb_list, skb) {
125 while (skb_off < skb->len) {
126 to_copy = min_t(unsigned int, PAGE_SIZE - map_off,
129 BUG_ON(map_page >= RDS_CONG_MAP_PAGES);
131 /* only returns 0 or -error */
132 ret = skb_copy_bits(skb, skb_off,
133 (void *)map->m_page_addrs[map_page] + map_off,
139 if (map_off == PAGE_SIZE) {
146 rds_cong_map_updated(map, ~(u64) 0);
149 struct rds_tcp_desc_arg {
150 struct rds_conn_path *conn_path;
154 static int rds_tcp_data_recv(read_descriptor_t *desc, struct sk_buff *skb,
155 unsigned int offset, size_t len)
157 struct rds_tcp_desc_arg *arg = desc->arg.data;
158 struct rds_conn_path *cp = arg->conn_path;
159 struct rds_tcp_connection *tc = cp->cp_transport_data;
160 struct rds_tcp_incoming *tinc = tc->t_tinc;
161 struct sk_buff *clone;
162 size_t left = len, to_copy;
164 rdsdebug("tcp data tc %p skb %p offset %u len %zu\n", tc, skb, offset,
168 * tcp_read_sock() interprets partial progress as an indication to stop
173 tinc = kmem_cache_alloc(rds_tcp_incoming_slab,
176 desc->error = -ENOMEM;
180 rdsdebug("alloced tinc %p\n", tinc);
181 rds_inc_path_init(&tinc->ti_inc, cp,
182 &cp->cp_conn->c_faddr);
183 tinc->ti_inc.i_rx_lat_trace[RDS_MSG_RX_HDR] =
187 * XXX * we might be able to use the __ variants when
188 * we've already serialized at a higher level.
190 skb_queue_head_init(&tinc->ti_skb_list);
193 if (left && tc->t_tinc_hdr_rem) {
194 to_copy = min(tc->t_tinc_hdr_rem, left);
195 rdsdebug("copying %zu header from skb %p\n", to_copy,
197 skb_copy_bits(skb, offset,
198 (char *)&tinc->ti_inc.i_hdr +
199 sizeof(struct rds_header) -
202 tc->t_tinc_hdr_rem -= to_copy;
206 if (tc->t_tinc_hdr_rem == 0) {
207 /* could be 0 for a 0 len message */
208 tc->t_tinc_data_rem =
209 be32_to_cpu(tinc->ti_inc.i_hdr.h_len);
210 tinc->ti_inc.i_rx_lat_trace[RDS_MSG_RX_START] =
215 if (left && tc->t_tinc_data_rem) {
216 to_copy = min(tc->t_tinc_data_rem, left);
218 clone = pskb_extract(skb, offset, to_copy, arg->gfp);
220 desc->error = -ENOMEM;
224 skb_queue_tail(&tinc->ti_skb_list, clone);
226 rdsdebug("skb %p data %p len %d off %u to_copy %zu -> "
227 "clone %p data %p len %d\n",
228 skb, skb->data, skb->len, offset, to_copy,
229 clone, clone->data, clone->len);
231 tc->t_tinc_data_rem -= to_copy;
236 if (tc->t_tinc_hdr_rem == 0 && tc->t_tinc_data_rem == 0) {
237 struct rds_connection *conn = cp->cp_conn;
239 if (tinc->ti_inc.i_hdr.h_flags == RDS_FLAG_CONG_BITMAP)
240 rds_tcp_cong_recv(conn, tinc);
242 rds_recv_incoming(conn, &conn->c_faddr,
247 tc->t_tinc_hdr_rem = sizeof(struct rds_header);
248 tc->t_tinc_data_rem = 0;
250 rds_inc_put(&tinc->ti_inc);
255 rdsdebug("returning len %zu left %zu skb len %d rx queue depth %d\n",
257 skb_queue_len(&tc->t_sock->sk->sk_receive_queue));
261 /* the caller has to hold the sock lock */
262 static int rds_tcp_read_sock(struct rds_conn_path *cp, gfp_t gfp)
264 struct rds_tcp_connection *tc = cp->cp_transport_data;
265 struct socket *sock = tc->t_sock;
266 read_descriptor_t desc;
267 struct rds_tcp_desc_arg arg;
269 /* It's like glib in the kernel! */
272 desc.arg.data = &arg;
274 desc.count = 1; /* give more than one skb per call */
276 tcp_read_sock(sock->sk, &desc, rds_tcp_data_recv);
277 rdsdebug("tcp_read_sock for tc %p gfp 0x%x returned %d\n", tc, gfp,
284 * We hold the sock lock to serialize our rds_tcp_recv->tcp_read_sock from
287 * if we fail to allocate we're in trouble.. blindly wait some time before
288 * trying again to see if the VM can free up something for us.
290 int rds_tcp_recv_path(struct rds_conn_path *cp)
292 struct rds_tcp_connection *tc = cp->cp_transport_data;
293 struct socket *sock = tc->t_sock;
296 rdsdebug("recv worker path [%d] tc %p sock %p\n",
297 cp->cp_index, tc, sock);
300 ret = rds_tcp_read_sock(cp, GFP_KERNEL);
301 release_sock(sock->sk);
306 void rds_tcp_data_ready(struct sock *sk)
308 void (*ready)(struct sock *sk);
309 struct rds_conn_path *cp;
310 struct rds_tcp_connection *tc;
312 rdsdebug("data ready sk %p\n", sk);
314 read_lock_bh(&sk->sk_callback_lock);
315 cp = sk->sk_user_data;
316 if (!cp) { /* check for teardown race */
317 ready = sk->sk_data_ready;
321 tc = cp->cp_transport_data;
322 ready = tc->t_orig_data_ready;
323 rds_tcp_stats_inc(s_tcp_data_ready_calls);
325 if (rds_tcp_read_sock(cp, GFP_ATOMIC) == -ENOMEM) {
327 if (!rds_destroy_pending(cp->cp_conn))
328 queue_delayed_work(rds_wq, &cp->cp_recv_w, 0);
332 read_unlock_bh(&sk->sk_callback_lock);
336 int rds_tcp_recv_init(void)
338 rds_tcp_incoming_slab = kmem_cache_create("rds_tcp_incoming",
339 sizeof(struct rds_tcp_incoming),
341 if (!rds_tcp_incoming_slab)
346 void rds_tcp_recv_exit(void)
348 kmem_cache_destroy(rds_tcp_incoming_slab);