After the patch that introduced this function was posted on the linux-scsi mailing list an explanation was posted why this patch is correct. Since that explanation contains important information, add a summary of it above the code that explanation applies to. See also http://www.spinics.net/lists/linux-scsi/msg106326.html. References: e494f6a72839 ("[SCSI] improve eh timeout handler") Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxxxxxx> Cc: Hannes Reinecke <hare@xxxxxxx> --- drivers/scsi/scsi_error.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index ac3196420435..19cafa3efb17 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -116,6 +116,12 @@ static int scsi_host_eh_past_deadline(struct Scsi_Host *shost) /** * scmd_eh_abort_handler - Handle command aborts * @work: command to be aborted. + * + * Note: this function must be called only for a command that has timed out. + * Because the block layer sets REQ_ATOM_COMPLETE before it calls + * scsi_times_out(), any .scsi_done() calls from the LLD for commands that + * have timed out do not have any effect. Hence it is safe to call + * scsi_finish_command() from this function. */ void scmd_eh_abort_handler(struct work_struct *work) -- 2.12.2