[ 069/171] ceph: dont set WRITE_PENDING too early

From: Greg Kroah-Hartman
Date: Thu Nov 22 2012 - 16:31:44 EST


3.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Alex Elder <elder@xxxxxxxxxxx>

(cherry picked from commit e10c758e4031a801ea4d2f8fb39bf14c2658d74b)

prepare_write_connect() prepares a connect message, then sets
WRITE_PENDING on the connection. Then *after* this, it calls
prepare_connect_authorizer(), which updates the content of the
connection buffer already queued for sending. It's also possible it
will result in prepare_write_connect() returning -EAGAIN despite the
WRITE_PENDING big getting set.

Fix this by preparing the connect authorizer first, setting the
WRITE_PENDING bit only after that is done.

Partially addresses http://tracker.newdream.net/issues/2424

Signed-off-by: Alex Elder <elder@xxxxxxxxxxx>
Reviewed-by: Sage Weil <sage@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/ceph/messenger.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -697,6 +697,7 @@ static int prepare_write_connect(struct
{
unsigned global_seq = get_global_seq(con->msgr, 0);
int proto;
+ int ret;

switch (con->peer_name.type) {
case CEPH_ENTITY_TYPE_MON:
@@ -723,11 +724,14 @@ static int prepare_write_connect(struct
con->out_connect.flags = 0;

ceph_con_out_kvec_add(con, sizeof (con->out_connect), &con->out_connect);
+ ret = prepare_connect_authorizer(con);
+ if (ret)
+ return ret;

con->out_more = 0;
set_bit(WRITE_PENDING, &con->state);

- return prepare_connect_authorizer(con);
+ return 0;
}

/*


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