IO管理和磁盘调度

1、 输入井 作业 4 作业 3 作业 5 作业 2 输出井 作业 3 作业 2 作业 4 作业 1 作业4 作业3 作业2 取输出存输出取输入存输入 输入设备 主 机 作业5 作业1 打印机 读过程从 设备读数 到缓冲区 写过程将 缓冲数据 写入磁盘 写过程将 缓冲数据 送打印机 读过程将 磁盘数据 读入缓冲 Applications Windows Services WMI Service User-Mode PnP Manager Setup Components Setup Components Setup Components WDM WMI Routines PnP Manager P

2、ower Manager I/O Manager Driver 1Driver 2 HAL .inf files .cat files Registry User Mode Kernel Mode I/O System Drivers Call Nt ReadFile() Dismiss interrupt Call Invoke driver() Wait or return to caller Initiate I/O operation Return to caller Call ReadFile() Call NtReadFile() Return to caller Int 2E R

3、eturn to caller Application KERNEL32.DLL NTDLL.DLL NTOSKRNL.EXE NTOSKRNL.EXE DRIVER.SYS ReadFile NtReadFile KiSystemService NtReadFile Whether to wait depends on overlapped flag Environment subsystem or DLL User mode Kernel mode NtWriteFile(file_handle, char_buffer) System services I/O manager Write

4、 data at specified byte offset within a file File system driver Translate file-relative byte offset into disk-relative byte offset, and call next driver (via I/O manager) File system driver Disk driver Call driver to write data at disk-relative byte offset Translate disk-relative byte offset into physical location, and transfer data Call next driver to write data to Disk 3 at disk- relative byte offset M