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scsi: documentation: scsi_eh: updates for EH changes

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SCSI_SOFTIRQ and scsi_softirq() are no longer used. Change to block layer
equivalents.

scsi_setup_cmd_retry() has been deleted. Remove references to it.

SCSI_EH_CANCEL_CMD has been deleted. Remove references to it.

scsi_eh_abort_cmds() has been deleted. Remove references to it.

[mkp: fixed START STOP UNIT]

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20241219214928.1170302-1-rdunlap@infradead.org
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Randy Dunlap 2024-12-19 13:49:28 -08:00 committed by Martin K. Petersen
parent faaf18d3f3
commit a9dcee18a2
1 changed files with 9 additions and 37 deletions
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46
Documentation/scsi/scsi_eh.rst
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@ -54,13 +54,13 @@ invoking hostt->queuecommand() or the block layer will time it out.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
For all non-EH commands, scsi_done() is the completion callback. It For all non-EH commands, scsi_done() is the completion callback. It
just calls blk_complete_request() to delete the block layer timer and just calls blk_mq_complete_request() to delete the block layer timer and
raise SCSI_SOFTIRQ raise BLOCK_SOFTIRQ.
SCSI_SOFTIRQ handler scsi_softirq calls scsi_decide_disposition() to The BLOCK_SOFTIRQ indirectly calls scsi_complete(), which calls
determine what to do with the command. scsi_decide_disposition() scsi_decide_disposition() to determine what to do with the command.
looks at the scmd->result value and sense data to determine what to do scsi_decide_disposition() looks at the scmd->result value and sense
with the command. data to determine what to do with the command.
- SUCCESS - SUCCESS
@ -110,7 +110,7 @@ The timeout handler is scsi_timeout(). When a timeout occurs, this function
retry which failed), when retries are exceeded, or when the EH deadline is retry which failed), when retries are exceeded, or when the EH deadline is
expired. In these cases Step #3 is taken. expired. In these cases Step #3 is taken.
3. scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD) is invoked for the 3. scsi_eh_scmd_add(scmd) is invoked for the
command. See [1-4] for more information. command. See [1-4] for more information.
1.3 Asynchronous command aborts 1.3 Asynchronous command aborts
@ -277,7 +277,6 @@ scmd->allowed.
:ACTION: scsi_eh_finish_cmd() is invoked to EH-finish scmd :ACTION: scsi_eh_finish_cmd() is invoked to EH-finish scmd
- scsi_setup_cmd_retry()
- move from local eh_work_q to local eh_done_q - move from local eh_work_q to local eh_done_q
:LOCKING: none :LOCKING: none
@ -317,7 +316,7 @@ scmd->allowed.
``scsi_eh_get_sense`` ``scsi_eh_get_sense``
This action is taken for each error-completed This action is taken for each error-completed
(!SCSI_EH_CANCEL_CMD) commands without valid sense data. Most command without valid sense data. Most
SCSI transports/LLDDs automatically acquire sense data on SCSI transports/LLDDs automatically acquire sense data on
command failures (autosense). Autosense is recommended for command failures (autosense). Autosense is recommended for
performance reasons and as sense information could get out of performance reasons and as sense information could get out of
@ -347,30 +346,6 @@ scmd->allowed.
- otherwise - otherwise
No action. No action.
3. If !list_empty(&eh_work_q), invoke scsi_eh_abort_cmds().
``scsi_eh_abort_cmds``
This action is taken for each timed out command when
no_async_abort is enabled in the host template.
hostt->eh_abort_handler() is invoked for each scmd. The
handler returns SUCCESS if it has succeeded to make LLDD and
all related hardware forget about the scmd.
If a timedout scmd is successfully aborted and the sdev is
either offline or ready, scsi_eh_finish_cmd() is invoked for
the scmd. Otherwise, the scmd is left in eh_work_q for
higher-severity actions.
Note that both offline and ready status mean that the sdev is
ready to process new scmds, where processing also implies
immediate failing; thus, if a sdev is in one of the two
states, no further recovery action is needed.
Device readiness is tested using scsi_eh_tur() which issues
TEST_UNIT_READY command. Note that the scmd must have been
aborted successfully before reusing it for TEST_UNIT_READY.
4. If !list_empty(&eh_work_q), invoke scsi_eh_ready_devs() 4. If !list_empty(&eh_work_q), invoke scsi_eh_ready_devs()
``scsi_eh_ready_devs`` ``scsi_eh_ready_devs``
@ -384,7 +359,7 @@ scmd->allowed.
For each sdev which has failed scmds with valid sense data For each sdev which has failed scmds with valid sense data
of which scsi_check_sense()'s verdict is FAILED, of which scsi_check_sense()'s verdict is FAILED,
START_STOP_UNIT command is issued w/ start=1. Note that START STOP UNIT command is issued w/ start=1. Note that
as we explicitly choose error-completed scmds, it is known as we explicitly choose error-completed scmds, it is known
that lower layers have forgotten about the scmd and we can that lower layers have forgotten about the scmd and we can
reuse it for STU. reuse it for STU.
@ -478,9 +453,6 @@ except for #1 must be implemented by eh_strategy_handler().
- shost->host_failed is zero. - shost->host_failed is zero.
- Each scmd is in such a state that scsi_setup_cmd_retry() on the
scmd doesn't make any difference.
- shost->eh_cmd_q is cleared. - shost->eh_cmd_q is cleared.
- Each scmd->eh_entry is cleared. - Each scmd->eh_entry is cleared.