diff options
Diffstat (limited to 'drivers/base/core.c')
| -rw-r--r-- | drivers/base/core.c | 43 |
1 files changed, 28 insertions, 15 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c index c7b0925f627..c7cfadcf675 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -50,6 +50,28 @@ static struct kobject *dev_kobj; struct kobject *sysfs_dev_char_kobj; struct kobject *sysfs_dev_block_kobj; +static DEFINE_MUTEX(device_hotplug_lock); + +void lock_device_hotplug(void) +{ + mutex_lock(&device_hotplug_lock); +} + +void unlock_device_hotplug(void) +{ + mutex_unlock(&device_hotplug_lock); +} + +int lock_device_hotplug_sysfs(void) +{ + if (mutex_trylock(&device_hotplug_lock)) + return 0; + + /* Avoid busy looping (5 ms of sleep should do). */ + msleep(5); + return restart_syscall(); +} + #ifdef CONFIG_BLOCK static inline int device_is_not_partition(struct device *dev) { @@ -407,9 +429,9 @@ static ssize_t online_show(struct device *dev, struct device_attribute *attr, { bool val; - lock_device_hotplug(); + device_lock(dev); val = !dev->offline; - unlock_device_hotplug(); + device_unlock(dev); return sprintf(buf, "%u\n", val); } @@ -423,7 +445,10 @@ static ssize_t online_store(struct device *dev, struct device_attribute *attr, if (ret < 0) return ret; - lock_device_hotplug(); + ret = lock_device_hotplug_sysfs(); + if (ret) + return ret; + ret = val ? device_online(dev) : device_offline(dev); unlock_device_hotplug(); return ret < 0 ? ret : count; @@ -1450,18 +1475,6 @@ int __init devices_init(void) return -ENOMEM; } -static DEFINE_MUTEX(device_hotplug_lock); - -void lock_device_hotplug(void) -{ - mutex_lock(&device_hotplug_lock); -} - -void unlock_device_hotplug(void) -{ - mutex_unlock(&device_hotplug_lock); -} - static int device_check_offline(struct device *dev, void *not_used) { int ret; |