net: Unmap fragment page once iterator is done (aeb193ea) · Commits · 戴 / test

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 ), that is, only call skb_abort_seq_read() if the sequential read is actually aborted. Signed-off-by:

Wedson Almeida Filho <wedsonaf@gmail.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

drivers/scsi/libiscsi_tcp.c

+0 −1

Original line number	Diff line number	Diff line
		@@ -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);

net/batman-adv/main.c

+0 −1

Original line number	Diff line number	Diff line
		@@ -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);
		}

net/core/skbuff.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -2541,8 +2541,13 @@ 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;

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