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Commit a4107026 authored by Sage Weil's avatar Sage Weil
Browse files

libceph: (re)initialize bio_iter on start of message receive 



Previously, we were opportunistically initializing the bio_iter if it
appeared to be uninitialized in the middle of the read path.  The problem
is that a sequence like:

 - start reading message
 - initialize bio_iter
 - read half a message
 - messenger fault, reconnect
 - restart reading message
 - ** bio_iter now non-NULL, not reinitialized **
 - read past end of bio, crash

Instead, initialize the bio_iter unconditionally when we allocate/claim
the message for read.

Signed-off-by: default avatarSage Weil <sage@inktank.com>
Reviewed-by: default avatarAlex Elder <elder@inktank.com>
Reviewed-by: default avatarYehuda Sadeh <yehuda@inktank.com>
parent 6194ea89

net/ceph/messenger.c

+6 −5
Original line number Diff line number Diff line
@@ -1872,6 +1872,11 @@ static int read_partial_message(struct ceph_connection *con) 
		else

			con->in_msg_pos.page_pos = 0;

		con->in_msg_pos.data_pos = 0;



#ifdef CONFIG_BLOCK

		if (m->bio)

			init_bio_iter(m->bio, &m->bio_iter, &m->bio_seg);

#endif

	}



	/* front */
@@ -1888,10 +1893,6 @@ static int read_partial_message(struct ceph_connection *con) 
		if (ret <= 0)

			return ret;

	}

#ifdef CONFIG_BLOCK

	if (m->bio && !m->bio_iter)

		init_bio_iter(m->bio, &m->bio_iter, &m->bio_seg);

#endif



	/* (page) data */

	while (con->in_msg_pos.data_pos < data_len) {
@@ -1902,7 +1903,7 @@ static int read_partial_message(struct ceph_connection *con) 
				return ret;

#ifdef CONFIG_BLOCK

		} else if (m->bio) {



			BUG_ON(!m->bio_iter);

			ret = read_partial_message_bio(con,

						 &m->bio_iter, &m->bio_seg,

						 data_len, do_datacrc);