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authorHannes Reinecke <hare@suse.de>2017-04-06 15:36:35 +0200
committerMartin K. Petersen <martin.petersen@oracle.com>2017-04-06 13:07:33 -0400
commita06586325f371c0f0f6095454b5beca0602eaab4 (patch)
treee87937fc00ab8e22047df50090686f55731d3940 /Documentation/scsi
parent2171b6d08bf8c2b826922b94e24ba36b00cb78b3 (diff)
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scsi: make asynchronous aborts mandatory
There hasn't been any reports for HBAs where asynchronous abort would not work, so we should make it mandatory and remove the fallback. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'Documentation/scsi')
-rw-r--r--Documentation/scsi/scsi_eh.txt18
1 files changed, 6 insertions, 12 deletions
diff --git a/Documentation/scsi/scsi_eh.txt b/Documentation/scsi/scsi_eh.txt
index 4edb9c1cbef5..11e447bdb3a5 100644
--- a/Documentation/scsi/scsi_eh.txt
+++ b/Documentation/scsi/scsi_eh.txt
@@ -70,7 +70,7 @@ with the command.
scmd is requeued to blk queue.
- otherwise
- scsi_eh_scmd_add(scmd, 0) is invoked for the command. See
+ scsi_eh_scmd_add(scmd) is invoked for the command. See
[1-3] for details of this function.
@@ -103,9 +103,7 @@ function
eh_timed_out() callback did not handle the command.
Step #2 is taken.
- 2. If the host supports asynchronous completion (as indicated by the
- no_async_abort setting in the host template) scsi_abort_command()
- is invoked to schedule an asynchrous abort.
+ 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),
@@ -127,16 +125,13 @@ function
scmds enter EH via scsi_eh_scmd_add(), which does the following.
- 1. Turns on scmd->eh_eflags as requested. It's 0 for error
- completions and SCSI_EH_CANCEL_CMD for timeouts.
+ 1. Links scmd->eh_entry to shost->eh_cmd_q
- 2. Links scmd->eh_entry to shost->eh_cmd_q
+ 2. Sets SHOST_RECOVERY bit in shost->shost_state
- 3. Sets SHOST_RECOVERY bit in shost->shost_state
+ 3. Increments shost->host_failed
- 4. Increments shost->host_failed
-
- 5. Wakes up SCSI EH thread if shost->host_busy == shost->host_failed
+ 4. Wakes up SCSI EH thread if shost->host_busy == shost->host_failed
As can be seen above, once any scmd is added to shost->eh_cmd_q,
SHOST_RECOVERY shost_state bit is turned on. This prevents any new
@@ -252,7 +247,6 @@ scmd->allowed.
1. Error completion / time out
ACTION: scsi_eh_scmd_add() is invoked for scmd
- - set scmd->eh_eflags
- add scmd to shost->eh_cmd_q
- set SHOST_RECOVERY
- shost->host_failed++