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 <wedso...@gmail.com>
---
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
--
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