diff options
| author | Julian Wiedmann <jwi@linux.ibm.com> | 2020-11-20 10:09:38 +0100 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2020-11-20 18:59:48 -0800 |
| commit | 8908f36d20d8ba610d3a7d110b3049b5853b9bb1 (patch) | |
| tree | 65a2d0be18a156d4de19b615cba565d0b67f4683 /drivers/s390/net/qeth_core.h | |
| parent | 34c7f50f7d0d36fa663c74aee39e25e912505320 (diff) | |
s390/qeth: fix af_iucv notification race
The two expected notification sequences are
1. TX_NOTIFY_PENDING with a subsequent TX_NOTIFY_DELAYED_*, when
our TX completion code first observed the pending TX and the QAOB
then completes at a later time; or
2. TX_NOTIFY_OK, when qeth_qdio_handle_aob() picked up the QAOB
completion before our TX completion code even noticed that the TX
was pending.
But as qeth_iqd_tx_complete() and qeth_qdio_handle_aob() can run
concurrently, we may end up with a race that results in a sequence of
TX_NOTIFY_DELAYED_* followed by TX_NOTIFY_PENDING. Which would confuse
the af_iucv code in its tracking of pending transmits.
Rework the notification code, so that qeth_qdio_handle_aob() defers its
notification if the TX completion code is still active.
Fixes: b333293058aa ("qeth: add support for af_iucv HiperSockets transport")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/s390/net/qeth_core.h')
| -rw-r--r-- | drivers/s390/net/qeth_core.h | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/drivers/s390/net/qeth_core.h b/drivers/s390/net/qeth_core.h index f73b4756ed5e..b235393e091c 100644 --- a/drivers/s390/net/qeth_core.h +++ b/drivers/s390/net/qeth_core.h @@ -417,10 +417,13 @@ enum qeth_qdio_out_buffer_state { QETH_QDIO_BUF_EMPTY, /* Filled by driver; owned by hardware in order to be sent. */ QETH_QDIO_BUF_PRIMED, - /* Identified to be pending in TPQ. */ + /* Discovered by the TX completion code: */ QETH_QDIO_BUF_PENDING, - /* Found in completion queue. */ - QETH_QDIO_BUF_IN_CQ, + /* Finished by the TX completion code: */ + QETH_QDIO_BUF_NEED_QAOB, + /* Received QAOB notification on CQ: */ + QETH_QDIO_BUF_QAOB_OK, + QETH_QDIO_BUF_QAOB_ERROR, /* Handled via transfer pending / completion queue. */ QETH_QDIO_BUF_HANDLED_DELAYED, }; |