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| author | Sebastian Ott <sebott@linux.vnet.ibm.com> | 2010-05-26 23:27:07 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <sky@mschwide.boeblingen.de.ibm.com> | 2010-05-26 23:27:09 +0200 |
| commit | c560d105a197464603247bf55962fc7f23c8cb62 (patch) | |
| tree | 04f9738638aff5f4825fc2567540d288ffd4518a /drivers/s390 | |
| parent | a65a3e82b5b5f8f70cc0d51498441585d5b381f1 (diff) | |
| download | linux-3.10-c560d105a197464603247bf55962fc7f23c8cb62.tar.gz linux-3.10-c560d105a197464603247bf55962fc7f23c8cb62.tar.bz2 linux-3.10-c560d105a197464603247bf55962fc7f23c8cb62.zip | |
[S390] ccwgroup: add locking around drvdata access
Several processes may concurrently try to create a group device
from the same ccw_device(s). Add locking arround the drvdata
access to prevent race conditions.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'drivers/s390')
| -rw-r--r-- | drivers/s390/cio/ccwgroup.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/s390/cio/ccwgroup.c b/drivers/s390/cio/ccwgroup.c index 5f97ea2ee6b..97b25d68e3e 100644 --- a/drivers/s390/cio/ccwgroup.c +++ b/drivers/s390/cio/ccwgroup.c @@ -123,8 +123,10 @@ ccwgroup_release (struct device *dev) for (i = 0; i < gdev->count; i++) { if (gdev->cdev[i]) { + spin_lock_irq(gdev->cdev[i]->ccwlock); if (dev_get_drvdata(&gdev->cdev[i]->dev) == gdev) dev_set_drvdata(&gdev->cdev[i]->dev, NULL); + spin_unlock_irq(gdev->cdev[i]->ccwlock); put_device(&gdev->cdev[i]->dev); } } @@ -262,11 +264,14 @@ int ccwgroup_create_from_string(struct device *root, unsigned int creator_id, goto error; } /* Don't allow a device to belong to more than one group. */ + spin_lock_irq(gdev->cdev[i]->ccwlock); if (dev_get_drvdata(&gdev->cdev[i]->dev)) { + spin_unlock_irq(gdev->cdev[i]->ccwlock); rc = -EINVAL; goto error; } dev_set_drvdata(&gdev->cdev[i]->dev, gdev); + spin_unlock_irq(gdev->cdev[i]->ccwlock); } /* Check for sufficient number of bus ids. */ if (i < num_devices && !curr_buf) { @@ -303,8 +308,10 @@ int ccwgroup_create_from_string(struct device *root, unsigned int creator_id, error: for (i = 0; i < num_devices; i++) if (gdev->cdev[i]) { + spin_lock_irq(gdev->cdev[i]->ccwlock); if (dev_get_drvdata(&gdev->cdev[i]->dev) == gdev) dev_set_drvdata(&gdev->cdev[i]->dev, NULL); + spin_unlock_irq(gdev->cdev[i]->ccwlock); put_device(&gdev->cdev[i]->dev); gdev->cdev[i] = NULL; } |