@@ -95,19 +95,18 @@ function
- BLK_EH_RESET_TIMER
This indicates that more time is required to finish the
- command. Timer is restarted. This action is counted as a
- retry and only allowed scmd->allowed + 1(!) times. Once the
- limit is reached, action for BLK_EH_DONE is taken instead.
+ command. Timer is restarted.
- BLK_EH_DONE
eh_timed_out() callback did not handle the command.
Step #2 is taken.
- 2. scsi_abort_command() is invoked to schedule an asynchrous abort.
- Asynchronous abort are not invoked for commands which the
- SCSI_EH_ABORT_SCHEDULED flag is set (this indicates that the command
- already had been aborted once, and this is a retry which failed),
- or when the EH deadline is expired. In these case Step #3 is taken.
+ 2. scsi_abort_command() is invoked to schedule an asynchrous abort. which may
+ issue a retry scmd->allowed + 1 times. Asynchronous abort are not invoked
+ for commands which the SCSI_EH_ABORT_SCHEDULED flag is set (this indicates
+ that the command already had been aborted once, and this is a retry which
+ failed), when retries are exceeded, or when the EH deadline is expired. In
+ these case Step #3 is taken.
3. scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD) is invoked for the
command. See [1-4] for more information.
eh_timed_out() is not limited by scmd->allowed, and can reset timer forever, and retries happen in the abort handler. Fixes: c829c394165f ("[SCSI] FC transport : Avoid device offline cases by stalling aborts until device unblocked") Signed-off-by: Khazhismel Kumykov <khazhy@google.com> --- Documentation/scsi/scsi_eh.rst | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) I'm by no means a scsi expert, but this section didn't seem to line up with the code that's actually written. Aiming to at least save the confusion for the next person :) As written, it seems like scsi drivers implementing eh_timed_out can only issue RESET_TIMER a finite number of times, but e.g. virtio_scsi relies on being able to reset indefinitely. (thanks bart for the pointer to where the RESET_TIMER change happened!)