SystemTap

#! /usr/bin/env stap 

global host_no = 17
global channel = 0
global targetid = 0
global lunid = 15

# 推断io是否下发到iscsi
probe module("libiscsi").function("iscsi_queuecommand")
{
    if ( $host!=0 && $sc!=0 )
    {
        if ( $host->host_no==host_no && $sc->device->channel==channel && $sc->device->id==targetid && $sc->device->lun==lunid )
        {
            printf("====================send scsi=======================\n")
            printf("tag = %d\n", $sc->tag)
            printf("serial_number = %lu\n", $sc->serial_number)
            printf("jiffies_at_alloc = %lu\n", $sc->jiffies_at_alloc)
            print_backtrace()        
            printf("\n")
        }
    }
}


probe kernel.function("do_sync_read")
{
    if ($filp!=0)
    {
        if ($filp->f_inode!=0)
        {
            if ($filp->f_inode->i_ino == 3978543828)
            {
                printf("===========================================do_sync_read\n\n")
            }
        }
    }
}

# 推断IO在iscsi被正确下发
probe module("libiscsi").statement("iscsi_queuecommand@libiscsi.c:1690")
{
    if ( $host!=0 && $sc!=0 )
    {
        if ( $host->host_no==host_no && $sc->device->channel==channel && $sc->device->id==targetid && $sc->device->lun==lunid )
        {
            printf("====================cmd sended=======================\n")
            printf("reason=%d\n", $reason)
            printf("\n")
        }
    }
}

# 推断IO是否返回
probe module("libiscsi").function("__iscsi_put_task")
{
    if ($task != 0)
    {

        if ($task->sc != 0)
        {
            if ( $task->sc->device->host->host_no==host_no && $task->sc->device->channel==channel && $task->sc->device->id==targetid && $task->sc->device->lun==lunid )
            {
                printf("*************************recv scsi********************\n")
                printf("tag = %d\n", $task->sc->tag)
                printf("serial_number = %lu\n", $task->sc->serial_number)
                printf("jiffies_at_alloc = %lu\n", $task->sc->jiffies_at_alloc)
                print_backtrace()
                printf("\n")
           }
        }
    }
}