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Julian Wiedmann
f9e50b02a9
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 commitb91d9e67e5("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:405548959c("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>
Linux kernel
============
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