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authorSebastian Ott <sebott@linux.vnet.ibm.com>2009-06-22 12:08:21 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2009-06-22 12:08:23 +0200
commit181d95229b0931ee2ce6aad7348079cbc10e8d05 (patch)
tree9962496049dad3c4ed5695d09886d0804be51462 /drivers/s390/block
parente98bbaafcd1c47d30f3245517fb585f1aaaca4db (diff)
downloadblackbird-op-linux-181d95229b0931ee2ce6aad7348079cbc10e8d05.tar.gz
blackbird-op-linux-181d95229b0931ee2ce6aad7348079cbc10e8d05.zip
[S390] dasd: fix refcounting in dasd_change_state
To set a dasd online dasd_change_state is called twice. The first cycle will schedule initial analysis of the device, set the rc to -EAGAIN and will not touch the device state any more. The initial analysis will in turn call dasd_change_state to increase the state to the final DASD_STATE_ONLINE. If the dasd_change_state on the second thread outruns the other one both finish with the state set to DASD_STATE_ONLINE and the device refcount will be decreased by 2. Fix this by leaving dasd_change_state on rc == -EAGAIN so that the refcount will always be decreased by 1. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'drivers/s390/block')
-rw-r--r--drivers/s390/block/dasd.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 99e71536213a..749836668655 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -470,7 +470,7 @@ static int dasd_decrease_state(struct dasd_device *device)
*/
static void dasd_change_state(struct dasd_device *device)
{
- int rc;
+ int rc;
if (device->state == device->target)
/* Already where we want to go today... */
@@ -479,8 +479,10 @@ static void dasd_change_state(struct dasd_device *device)
rc = dasd_increase_state(device);
else
rc = dasd_decrease_state(device);
- if (rc && rc != -EAGAIN)
- device->target = device->state;
+ if (rc == -EAGAIN)
+ return;
+ if (rc)
+ device->target = device->state;
if (device->state == device->target) {
wake_up(&dasd_init_waitq);
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