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| author | Sebastian Ott <sebott@linux.vnet.ibm.com> | 2009-12-07 14:51:35 +0300 |
|---|---|---|
| committer | Martin Schwidefsky <sky@mschwide.boeblingen.de.ibm.com> | 2009-12-07 14:51:32 +0300 |
| commit | 56e6b796fe9b99287648fc5686aae00106b37bab (patch) | |
| tree | f0c75986905f3ff01ec1c801843f94923509af06 /drivers/s390/cio/device.c | |
| parent | 24a1872d6411c7cce82c0888a4fbea23e993e051 (diff) | |
| download | linux-56e6b796fe9b99287648fc5686aae00106b37bab.tar.xz | |
[S390] cio: fix quiesce state
DEV_STATE_QUIESCE is used to stop all IO on a busy subchannel.
This patch fixes the following problems related to the QUIESCE
state:
* Fix a potential race condition which could occur when the
resulting state was DEV_STATE_OFFLINE.
* Add missing locking around cio_disable_subchannel,
ccw_device_cancel_halt_clear and the cdev's handler.
* Loop until we know for sure that the subchannel is disabled.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'drivers/s390/cio/device.c')
| -rw-r--r-- | drivers/s390/cio/device.c | 35 |
1 files changed, 19 insertions, 16 deletions
diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c index e8cb99a63cc6..2b50f93b7fef 100644 --- a/drivers/s390/cio/device.c +++ b/drivers/s390/cio/device.c @@ -1130,33 +1130,36 @@ static int io_subchannel_chp_event(struct subchannel *sch, return 0; } -static void -io_subchannel_shutdown(struct subchannel *sch) +static void io_subchannel_shutdown(struct subchannel *sch) { struct ccw_device *cdev; int ret; + spin_lock_irq(sch->lock); cdev = sch_get_cdev(sch); - if (cio_is_console(sch->schid)) - return; + goto out_unlock; if (!sch->schib.pmcw.ena) - /* Nothing to do. */ - return; + goto out_unlock; ret = cio_disable_subchannel(sch); if (ret != -EBUSY) - /* Subchannel is disabled, we're done. */ - return; - cdev->private->state = DEV_STATE_QUIESCE; + goto out_unlock; if (cdev->handler) - cdev->handler(cdev, cdev->private->intparm, - ERR_PTR(-EIO)); - ret = ccw_device_cancel_halt_clear(cdev); - if (ret == -EBUSY) { - ccw_device_set_timeout(cdev, HZ/10); - wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev)); + cdev->handler(cdev, cdev->private->intparm, ERR_PTR(-EIO)); + while (ret == -EBUSY) { + cdev->private->state = DEV_STATE_QUIESCE; + ret = ccw_device_cancel_halt_clear(cdev); + if (ret == -EBUSY) { + ccw_device_set_timeout(cdev, HZ/10); + spin_unlock_irq(sch->lock); + wait_event(cdev->private->wait_q, + cdev->private->state != DEV_STATE_QUIESCE); + spin_lock_irq(sch->lock); + } + ret = cio_disable_subchannel(sch); } - cio_disable_subchannel(sch); +out_unlock: + spin_unlock_irq(sch->lock); } static int device_is_disconnected(struct ccw_device *cdev) |