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libceph: don't clear bio_iter in prepare_write_message()

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At one time it was necessary to clear a message's bio_iter field to
avoid a bad pointer dereference in write_partial_msg_pages().

That no longer seems to be the case.  Here's why.

The message's bio fields represent (in this case) outgoing data.
Between where the bio_iter is made NULL in prepare_write_message()
and the call in that function to prepare_message_data(), the
bio fields are never used.

In prepare_message_data(), init-bio_iter() is called, and the result
of that overwrites the value in the message's bio_iter field.

Because it gets overwritten anyway, there is no need to set it to
NULL.  So don't do it.

This resolves:
    http://tracker.ceph.com/issues/4402

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This commit is contained in:
Alex Elder 2013-03-06 23:39:39 -06:00 committed by Sage Weil
parent 07aa155878
commit 98a0370898
1 changed files with 0 additions and 4 deletions
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4
net/ceph/messenger.c
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@ -804,10 +804,6 @@ static void prepare_write_message(struct ceph_connection *con)
m->hdr.seq = cpu_to_le64(++con->out_seq);
m->needs_out_seq = false;
}
#ifdef CONFIG_BLOCK
else
m->bio_iter = NULL;
#endif
dout("prepare_write_message %p seq %lld type %d len %d+%d+%d (%zd)\n",
m, con->out_seq, le16_to_cpu(m->hdr.type),