[PATCH] libceph: init the cursor when preparing the sparse read

[xiubli@redhat.com]

From: Xiubo Li <xiubli@redhat.com>

The osd code has remove cursor initilizing code and this will make
the sparse read state into a infinite loop. We should initialize
the cursor just before each sparse-read in messnger v2.

Cc: stable@vger.kernel.org
URL: https://tracker.ceph.com/issues/64607
Fixes: 8e46a2d068c9 ("libceph: just wait for more data to be available on the socket")
Reported-by: Luis Henriques <lhenriques@suse.de>
Signed-off-by: Xiubo Li <xiubli@redhat.com>
---
 net/ceph/messenger_v2.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/ceph/messenger_v2.c b/net/ceph/messenger_v2.c
index a0ca5414b333..7ae0f80100f4 100644
--- a/net/ceph/messenger_v2.c
+++ b/net/ceph/messenger_v2.c
@@ -2025,6 +2025,7 @@ static int prepare_sparse_read_cont(struct ceph_connection *con)
 static int prepare_sparse_read_data(struct ceph_connection *con)
 {
 	struct ceph_msg *msg = con->in_msg;
+	u64 len = con->in_msg->sparse_read_total ? : data_len(con->in_msg);
 
 	dout("%s: starting sparse read\n", __func__);
 
@@ -2034,6 +2035,8 @@ static int prepare_sparse_read_data(struct ceph_connection *con)
 	if (!con_secure(con))
 		con->in_data_crc = -1;
 
+	ceph_msg_data_cursor_init(&con->v2.in_cursor, con->in_msg, len);
+
 	reset_in_kvecs(con);
 	con->v2.in_state = IN_S_PREPARE_SPARSE_DATA_CONT;
 	con->v2.data_len_remain = data_len(msg);
-- 
2.43.0