sfc: free multiple Rx buffers when required

When Rx packet data must be dropped, all the buffers
associated with that Rx packet must be freed. Extend
and rename efx_free_rx_buffer() to efx_free_rx_buffers()
and loop through all the fragments.
By doing so this patch fixes a possible memory leak.

Signed-off-by: Shradha Shah <sshah@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/sfc/rx.c b/drivers/net/ethernet/sfc/rx.c
index c0ad95d..809ea46 100644 (file)
--- a/drivers/net/ethernet/sfc/rx.c
+++ b/drivers/net/ethernet/sfc/rx.c
@@ -224,12 +224,17 @@ static void efx_unmap_rx_buffer(struct efx_nic *efx,
        }
 }
 
-static void efx_free_rx_buffer(struct efx_rx_buffer *rx_buf)
+static void efx_free_rx_buffers(struct efx_rx_queue *rx_queue,
+                               struct efx_rx_buffer *rx_buf,
+                               unsigned int num_bufs)
 {
-       if (rx_buf->page) {
-               put_page(rx_buf->page);
-               rx_buf->page = NULL;
-       }
+       do {
+               if (rx_buf->page) {
+                       put_page(rx_buf->page);
+                       rx_buf->page = NULL;
+               }
+               rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
+       } while (--num_bufs);
 }
 
 /* Attempt to recycle the page if there is an RX recycle ring; the page can
@@ -278,7 +283,7 @@ static void efx_fini_rx_buffer(struct efx_rx_queue *rx_queue,
        /* If this is the last buffer in a page, unmap and free it. */
        if (rx_buf->flags & EFX_RX_BUF_LAST_IN_PAGE) {
                efx_unmap_rx_buffer(rx_queue->efx, rx_buf);
-               efx_free_rx_buffer(rx_buf);
+               efx_free_rx_buffers(rx_queue, rx_buf, 1);
        }
        rx_buf->page = NULL;
 }
@@ -304,10 +309,7 @@ static void efx_discard_rx_packet(struct efx_channel *channel,
 
        efx_recycle_rx_pages(channel, rx_buf, n_frags);
 
-       do {
-               efx_free_rx_buffer(rx_buf);
-               rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
-       } while (--n_frags);
+       efx_free_rx_buffers(rx_queue, rx_buf, n_frags);
 }
 
 /**
@@ -431,11 +433,10 @@ efx_rx_packet_gro(struct efx_channel *channel, struct efx_rx_buffer *rx_buf,
 
        skb = napi_get_frags(napi);
        if (unlikely(!skb)) {
-               while (n_frags--) {
-                       put_page(rx_buf->page);
-                       rx_buf->page = NULL;
-                       rx_buf = efx_rx_buf_next(&channel->rx_queue, rx_buf);
-               }
+               struct efx_rx_queue *rx_queue;
+
+               rx_queue = efx_channel_get_rx_queue(channel);
+               efx_free_rx_buffers(rx_queue, rx_buf, n_frags);
                return;
        }
 
@@ -622,7 +623,10 @@ static void efx_rx_deliver(struct efx_channel *channel, u8 *eh,
 
        skb = efx_rx_mk_skb(channel, rx_buf, n_frags, eh, hdr_len);
        if (unlikely(skb == NULL)) {
-               efx_free_rx_buffer(rx_buf);
+               struct efx_rx_queue *rx_queue;
+
+               rx_queue = efx_channel_get_rx_queue(channel);
+               efx_free_rx_buffers(rx_queue, rx_buf, n_frags);
                return;
        }
        skb_record_rx_queue(skb, channel->rx_queue.core_index);
@@ -661,8 +665,12 @@ void __efx_rx_packet(struct efx_channel *channel)
         * loopback layer, and free the rx_buf here
         */
        if (unlikely(efx->loopback_selftest)) {
+               struct efx_rx_queue *rx_queue;
+
                efx_loopback_rx_packet(efx, eh, rx_buf->len);
-               efx_free_rx_buffer(rx_buf);
+               rx_queue = efx_channel_get_rx_queue(channel);
+               efx_free_rx_buffers(rx_queue, rx_buf,
+                                   channel->rx_pkt_n_frags);
                goto out;
        }