Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751410Ab3FYBZk (ORCPT ); Mon, 24 Jun 2013 21:25:40 -0400 Received: from mail-pd0-f180.google.com ([209.85.192.180]:64765 "EHLO mail-pd0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751223Ab3FYBZg (ORCPT ); Mon, 24 Jun 2013 21:25:36 -0400 From: Wedson Almeida Filho To: "David S. Miller" Cc: sergei.shtylyov@cogentembedded.com, Thomas Graf , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Wedson Almeida Filho Subject: [PATCH v3] net: Unmap fragment page once iterator is done Date: Mon, 24 Jun 2013 18:25:20 -0700 Message-Id: <1372123520-18287-1-git-send-email-wedsonaf@gmail.com> X-Mailer: git-send-email 1.7.9.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2475 Lines: 68 Callers of skb_seq_read() are currently forced to call skb_abort_seq_read() even when consuming all the data because the last call to skb_seq_read (the one that returns 0 to indicate the end) fails to unmap the last fragment page. With this patch callers will be allowed to traverse the SKB data by calling skb_prepare_seq_read() once and repeatedly calling skb_seq_read() as originally intended (and documented in the original commit 677e90eda - "[NET]: Zerocopy sequential reading of skb data"), that is, only call skb_abort_seq_read() if the sequential read is actually aborted. Signed-off-by: Wedson Almeida Filho --- drivers/scsi/libiscsi_tcp.c | 1 - net/batman-adv/main.c | 1 - net/core/skbuff.c | 7 ++++++- 3 files changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/scsi/libiscsi_tcp.c b/drivers/scsi/libiscsi_tcp.c index 552e8a2..448eae8 100644 --- a/drivers/scsi/libiscsi_tcp.c +++ b/drivers/scsi/libiscsi_tcp.c @@ -906,7 +906,6 @@ int iscsi_tcp_recv_skb(struct iscsi_conn *conn, struct sk_buff *skb, ISCSI_DBG_TCP(conn, "no more data avail. Consumed %d\n", consumed); *status = ISCSI_TCP_SKB_DONE; - skb_abort_seq_read(&seq); goto skb_done; } BUG_ON(segment->copied >= segment->size); diff --git a/net/batman-adv/main.c b/net/batman-adv/main.c index 51aafd6..08125f3 100644 --- a/net/batman-adv/main.c +++ b/net/batman-adv/main.c @@ -473,7 +473,6 @@ __be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr) crc = crc32c(crc, data, len); consumed += len; } - skb_abort_seq_read(&st); return htonl(crc); } diff --git a/net/core/skbuff.c b/net/core/skbuff.c index cfd777b..26ea1cf 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -2554,8 +2554,13 @@ unsigned int skb_seq_read(unsigned int consumed, const u8 **data, unsigned int block_limit, abs_offset = consumed + st->lower_offset; skb_frag_t *frag; - if (unlikely(abs_offset >= st->upper_offset)) + if (unlikely(abs_offset >= st->upper_offset)) { + if (st->frag_data) { + kunmap_atomic(st->frag_data); + st->frag_data = NULL; + } return 0; + } next_skb: block_limit = skb_headlen(st->cur_skb) + st->stepped_offset; -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/