scsi: core: scmd_eh_abort_handler(): Add a comment

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: e494f6a728 ("[SCSI] improved eh timeout handler")
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Bart Van Assche 2018-02-12 10:38:05 -08:00 committed by Martin K. Petersen
parent ed4414cef2
commit 923f46f9e9
1 changed files with 6 additions and 0 deletions

View File

@ -117,6 +117,12 @@ 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 marks a request as complete before it calls
* scsi_times_out(), a .scsi_done() call from the LLD for a command that has
* 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)