From 5c139ce9e1c2737a37454b607912da619d09637e Mon Sep 17 00:00:00 2001 From: Khazhismel Kumykov Date: Fri, 18 Feb 2022 16:16:01 -0800 Subject: scsi: core: docs: Update notes about scsi_times_out 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 Signed-off-by: Khazhismel Kumykov Signed-off-by: Martin K. Petersen --- Documentation/scsi/scsi_eh.rst | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) (limited to 'Documentation/scsi') 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. -- cgit v1.2.3