Hi Yuezhang.Mo > exfat_clear_volume_dirty() is only called in sync or umount context. > In sync or umount context, all requests will be issued with REQ_SYNC regardless of whether REQ_SYNC is > set when submitting buffer. > > And since the request of set VolumeDirty is issued with REQ_SYNC. So for simplicity, call sync_dirty_buffer() > unconditionally. REQ_FUA and REQ_PREFLUSH may not make much sense on SD cards or USB sticks. However, the behavior of SCSI/ATAPI type devices with lazy write cache is - Issue the SYNCHRONIZE_CACHE command to write all the data to the medium. - Issue a WRITE command with FORCE_UNIT_ACCESS (device does not use write cache) for the boot sector. This guarantees a strict write order. BR T.Kohada
