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| author |   Julian Wiedmann <jwi@linux.ibm.com> | 2019-12-05 14:33:04 +0100 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2019-12-05 12:25:05 -0800 |
| commit | f9e50b02a99c3ebbaa30690e8d5be28a5c2624eb (patch) | |
| tree | d62bad662fb722988ad846fb5b04940eca4ecef9 /drivers/s390/net/qeth_l2_main.c | |
| parent | s390/qeth: ensure linear access to packet headers (diff) | |
| download | linux-dev-f9e50b02a99c3ebbaa30690e8d5be28a5c2624eb.tar.xz linux-dev-f9e50b02a99c3ebbaa30690e8d5be28a5c2624eb.zip | |
s390/qeth: fix dangling IO buffers after halt/clear
The cio layer's intparm logic does not align itself well with how qeth
manages cmd IOs. When an active IO gets terminated via halt/clear, the
corresponding IRQ's intparm does not reflect the cmd buffer but rather
the intparm that was passed to ccw_device_halt() / ccw_device_clear().
This behaviour was recently clarified in
commit b91d9e67e50b ("s390/cio: fix intparm documentation").
As a result, qeth_irq() currently doesn't cancel a cmd that was
terminated via halt/clear. This primarily causes us to leak
card->read_cmd after the qeth device is removed, since our IO path still
holds a refcount for this cmd.
For qeth this means that we need to keep track of which IO is pending on
a device ('active_cmd'), and use this as the intparm when calling
halt/clear. Otherwise qeth_irq() can't match the subsequent IRQ to its
cmd buffer.
Since we now keep track of the _expected_ intparm, we can also detect
any mismatch; this would constitute a bug somewhere in the lower layers.
In this case cancel the active cmd - we effectively "lost" the IRQ and
should not expect any further notification for this IO.
Fixes: 405548959cc7 ("s390/qeth: add support for dynamically allocated cmds")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/s390/net/qeth_l2_main.c')
| -rw-r--r-- | drivers/s390/net/qeth_l2_main.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c index 989935d67b31..9086bc04fa6b 100644 --- a/drivers/s390/net/qeth_l2_main.c +++ b/drivers/s390/net/qeth_l2_main.c @@ -845,9 +845,9 @@ static int qeth_l2_set_online(struct ccwgroup_device *gdev) out_remove: qeth_l2_stop_card(card); - ccw_device_set_offline(CARD_DDEV(card)); - ccw_device_set_offline(CARD_WDEV(card)); - ccw_device_set_offline(CARD_RDEV(card)); + qeth_stop_channel(&card->data); + qeth_stop_channel(&card->write); + qeth_stop_channel(&card->read); qdio_free(CARD_DDEV(card)); mutex_unlock(&card->conf_mutex); @@ -878,9 +878,9 @@ static int __qeth_l2_set_offline(struct ccwgroup_device *cgdev, rtnl_unlock(); qeth_l2_stop_card(card); - rc = ccw_device_set_offline(CARD_DDEV(card)); - rc2 = ccw_device_set_offline(CARD_WDEV(card)); - rc3 = ccw_device_set_offline(CARD_RDEV(card)); + rc = qeth_stop_channel(&card->data); + rc2 = qeth_stop_channel(&card->write); + rc3 = qeth_stop_channel(&card->read); if (!rc) rc = (rc2) ? rc2 : rc3; if (rc) |