From: Khazhismel Kumykov <khazhy@google.com>
Date: Fri, 18 Feb 2022 16:16:01 -0800
Subject: [PATCH] scsi: core: docs: Update notes about scsi_times_out
Git-commit: 5c139ce9e1c2737a37454b607912da619d09637e
Patch-mainline: v5.18-rc1
References: jsc#PED-1559
Most importantly: eh_timed_out() is not limited by scmd->allowed, and can
reset timer forever.
Fixes: c829c394165f ("[SCSI] FC transport : Avoid device offline cases by stalling aborts until device unblocked")
Link: https://lore.kernel.org/r/20220219001601.3534043-1-khazhy@google.com
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Khazhismel Kumykov <khazhy@google.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Hannes Reinecke <hare@suse.com>
---
Documentation/scsi/scsi_eh.rst | 15 +++++++--------
1 file changed, 7 insertions(+), 8 deletions(-)
diff --git a/Documentation/scsi/scsi_eh.rst b/Documentation/scsi/scsi_eh.rst
index 7d78c2475615..885395dc1f15 100644
--- a/Documentation/scsi/scsi_eh.rst
+++ b/Documentation/scsi/scsi_eh.rst
@@ -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 asynchronous abort which may
+ issue a retry scmd->allowed + 1 times. Asynchronous aborts are not invoked
+ for commands for 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 cases 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.
--
2.35.3