blk_pre_runtime

函数名称：lk_pre_runtime_suspend - Pre runtime suspend check*@q: the queue of the device* Description:* This function will check if runtime suspend is allowed for the device* by examining if there are any requests pending in the queue

函数原型：int blk_pre_runtime_suspend(struct request_queue *q)

返回类型：int

参数：

类型	参数	名称
struct request_queue *	q

ret等于0

如果非dev则返回:ret

WARN_ON_ONCE(rpm_status != RPM_ACTIVE)

lk_set_pm_only - increment pm_only counter*@q: request queue pointer

ret等于负EBUSY

blk_freeze_queue_start(q)

percpu_ref_switch_to_atomic_sync - switch a percpu_ref to atomic mode*@ref: percpu_ref to switch to atomic mode* Schedule switching the ref to atomic mode, and wait for the* switch to complete. Caller must ensure that no other thread

如果判断percpu无计数引用则ret等于0

blk_mq_unfreeze_queue(q)

spin_lock_irq( & queue_lock)

如果ret小于0则pm_runtime_mark_last_busy(dev)

否则rpm_status等于RPM_SUSPENDING

spin_unlock_irq( & queue_lock)

如果ret则blk_clear_pm_only(q)

102

返回:ret

源代码转换工具开放的插件接口	X
支持：c/c++/esqlc/java Oracle/Informix/Mysql 插件可实现：逻辑报告代码生成和批量转换代码

函数逻辑报告