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authorJulian Wiedmann <jwi@linux.ibm.com>2019-11-14 11:19:17 +0100
committerDavid S. Miller <davem@davemloft.net>2019-11-15 03:16:51 +0100
commit17caeaa4766dc447d6669b0f195c3ead746386ba (patch)
treeefb071b31bf206bcfd3a40f7f46949cb27347b9b /drivers/s390/net
parents390/qeth: drop unwanted packets earlier in RX path (diff)
downloadlinux-17caeaa4766dc447d6669b0f195c3ead746386ba.tar.xz
linux-17caeaa4766dc447d6669b0f195c3ead746386ba.zip
s390/qeth: handle skb allocation error gracefully
When current code fails to allocate an skb in the RX path, it drops the whole RX buffer. Considering the large number of packets that a single RX buffer might contain, this is quite drastic. Skip over the packet instead, and try to extract the next packet from the RX buffer. Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/s390/net')
-rw-r--r--drivers/s390/net/qeth_core_main.c25
1 files changed, 10 insertions, 15 deletions
diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 467a9173058c..08185f76a727 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -5065,12 +5065,12 @@ struct sk_buff *qeth_core_get_next_skb(struct qeth_card *card,
struct qdio_buffer_element *element = *__element;
struct qdio_buffer *buffer = qethbuffer->buffer;
int offset = *__offset;
+ bool use_rx_sg = false;
+ unsigned int headroom;
struct sk_buff *skb;
int skb_len = 0;
void *data_ptr;
int data_len;
- int headroom = 0;
- int use_rx_sg = 0;
next_packet:
/* qeth_hdr must not cross element boundaries */
@@ -5086,6 +5086,7 @@ next_packet:
switch ((*hdr)->hdr.l2.id) {
case QETH_HEADER_TYPE_LAYER2:
skb_len = (*hdr)->hdr.l2.pkt_length;
+ headroom = 0;
break;
case QETH_HEADER_TYPE_LAYER3:
skb_len = (*hdr)->hdr.l3.length;
@@ -5120,11 +5121,10 @@ next_packet:
if (!skb_len)
return NULL;
- if (((skb_len >= card->options.rx_sg_cb) &&
- !IS_OSN(card) &&
- (!atomic_read(&card->force_alloc_skb))) ||
- (card->options.cq == QETH_CQ_ENABLED))
- use_rx_sg = 1;
+ use_rx_sg = (card->options.cq == QETH_CQ_ENABLED) ||
+ ((skb_len >= card->options.rx_sg_cb) &&
+ !atomic_read(&card->force_alloc_skb) &&
+ !IS_OSN(card));
if (use_rx_sg && qethbuffer->rx_skb) {
/* QETH_CQ_ENABLED only: */
@@ -5135,9 +5135,10 @@ next_packet:
skb = napi_alloc_skb(&card->napi, linear + headroom);
}
+
if (!skb)
- goto no_mem;
- if (headroom)
+ QETH_CARD_STAT_INC(card, rx_dropped_nomem);
+ else if (headroom)
skb_reserve(skb, headroom);
walk_packet:
@@ -5184,12 +5185,6 @@ walk_packet:
skb_shinfo(skb)->nr_frags);
}
return skb;
-no_mem:
- if (net_ratelimit()) {
- QETH_CARD_TEXT(card, 2, "noskbmem");
- }
- QETH_CARD_STAT_INC(card, rx_dropped_nomem);
- return NULL;
}
EXPORT_SYMBOL_GPL(qeth_core_get_next_skb);