diff options
| author | Ursula Braun <ubraun@linux.ibm.com> | 2019-02-04 13:44:45 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-02-04 09:11:19 -0800 |
| commit | b8649efad879c69c7ab1f19ce8814fcabef1f72b (patch) | |
| tree | c5f16db7dbde8bb5da8db0b74f538a2a58c78036 /net/smc/smc_tx.c | |
| parent | ad6f317f720f4a3121756c23831a43dda9b095e5 (diff) | |
net/smc: fix sender_free computation
In some scenarios a separate consumer cursor update is necessary.
The decision is made in smc_tx_consumer_cursor_update(). The
sender_free computation could be wrong:
The rx confirmed cursor is always smaller than or equal to the
rx producer cursor. The parameters in the smc_curs_diff() call
have to be exchanged, otherwise sender_free might even be negative.
And if more data arrives local_rx_ctrl.prod might be updated, enabling
a cursor difference between local_rx_ctrl.prod and rx confirmed cursor
larger than the RMB size. This case is not covered by smc_curs_diff().
Thus function smc_curs_diff_large() is introduced here.
If a recvmsg() is processed in parallel, local_tx_ctrl.cons might
change during smc_cdc_msg_send. Make sure rx_curs_confirmed is updated
with the actually sent local_tx_ctrl.cons value.
Fixes: e82f2e31f559 ("net/smc: optimize consumer cursor updates")
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/smc/smc_tx.c')
| -rw-r--r-- | net/smc/smc_tx.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/smc/smc_tx.c b/net/smc/smc_tx.c index 2fdfaff60cf9..f93f3580c100 100644 --- a/net/smc/smc_tx.c +++ b/net/smc/smc_tx.c @@ -595,7 +595,8 @@ void smc_tx_consumer_update(struct smc_connection *conn, bool force) if (to_confirm > conn->rmbe_update_limit) { smc_curs_copy(&prod, &conn->local_rx_ctrl.prod, conn); sender_free = conn->rmb_desc->len - - smc_curs_diff(conn->rmb_desc->len, &prod, &cfed); + smc_curs_diff_large(conn->rmb_desc->len, + &cfed, &prod); } if (conn->local_rx_ctrl.prod_flags.cons_curs_upd_req || |