MIRRORS/linux-yocto
1
0
Fork 0
mirror of git://git.yoctoproject.org/linux-yocto.git synced 2025-10-22 23:13:01 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity

scsi: documentation: scsi_eh: updates for EH changes

Browse Source 
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
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

46
Documentation/scsi/scsi_eh.rst
View File

@ -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
just calls blk_complete_request() to delete the block layer timer and
raise SCSI_SOFTIRQ
just calls blk_mq_complete_request() to delete the block layer timer and
raise BLOCK_SOFTIRQ.
SCSI_SOFTIRQ handler scsi_softirq calls scsi_decide_disposition() to
determine what to do with the command. scsi_decide_disposition()
looks at the scmd->result value and sense data to determine what to do
with the command.
The BLOCK_SOFTIRQ indirectly calls scsi_complete(), which calls
scsi_decide_disposition() to determine what to do with the command.
scsi_decide_disposition() looks at the scmd->result value and sense
data to determine what to do with the command.
- 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
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.
1.3 Asynchronous command aborts
@ -277,7 +277,6 @@ scmd->allowed.
: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
:LOCKING: none
@ -317,7 +316,7 @@ scmd->allowed.
``scsi_eh_get_sense``
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
command failures (autosense). Autosense is recommended for
performance reasons and as sense information could get out of
@ -347,30 +346,6 @@ scmd->allowed.
- otherwise
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()
``scsi_eh_ready_devs``
@ -384,7 +359,7 @@ scmd->allowed.
For each sdev which has failed scmds with valid sense data
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
that lower layers have forgotten about the scmd and we can
reuse it for STU.
@ -478,9 +453,6 @@ except for #1 must be implemented by eh_strategy_handler().
- 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.
- Each scmd->eh_entry is cleared.