diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 4a602853a98e..4362dcde74af 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include @@ -2248,3 +2249,61 @@ scsi_target_unblock(struct device *dev) device_for_each_child(dev, NULL, target_unblock); } EXPORT_SYMBOL_GPL(scsi_target_unblock); + + +struct work_queue_work { + struct work_struct work; + void (*fn)(void *); + void *data; +}; + +static void execute_in_process_context_work(void *data) +{ + void (*fn)(void *data); + struct work_queue_work *wqw = data; + + fn = wqw->fn; + data = wqw->data; + + kfree(wqw); + + fn(data); +} + +/** + * scsi_execute_in_process_context - reliably execute the routine with user context + * @fn: the function to execute + * @data: data to pass to the function + * + * Executes the function immediately if process context is available, + * otherwise schedules the function for delayed execution. + * + * Returns: 0 - function was executed + * 1 - function was scheduled for execution + * <0 - error + */ +int scsi_execute_in_process_context(void (*fn)(void *data), void *data) +{ + struct work_queue_work *wqw; + + if (!in_interrupt()) { + fn(data); + return 0; + } + + wqw = kmalloc(sizeof(struct work_queue_work), GFP_ATOMIC); + + if (unlikely(!wqw)) { + printk(KERN_ERR "Failed to allocate memory\n"); + WARN_ON(1); + return -ENOMEM; + } + + INIT_WORK(&wqw->work, execute_in_process_context_work, wqw); + wqw->fn = fn; + wqw->data = data; + schedule_work(&wqw->work); + + return 1; +} +EXPORT_SYMBOL_GPL(scsi_execute_in_process_context); diff --git a/include/scsi/scsi.h b/include/scsi/scsi.h index c60b8ff2f5e4..9c331258bc27 100644 --- a/include/scsi/scsi.h +++ b/include/scsi/scsi.h @@ -433,4 +433,6 @@ struct scsi_lun { /* Used to obtain the PCI location of a device */ #define SCSI_IOCTL_GET_PCI 0x5387 +int scsi_execute_in_process_context(void (*fn)(void *data), void *data); + #endif /* _SCSI_SCSI_H */