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authorHannes Reinecke <hare@suse.de>2017-04-06 15:36:33 +0200
committerMartin K. Petersen <martin.petersen@oracle.com>2017-04-06 13:07:33 -0400
commit8e8c9d01c5ea33e0d21f13264a9caeed255526d1 (patch)
treebf9748c6e26a839b43cf841ceb59b4efa4bc1ec4 /Documentation/scsi
parent909657615d9b3ce709be4fd95b9a9e8c8c7c2be6 (diff)
downloadlinux-8e8c9d01c5ea33e0d21f13264a9caeed255526d1.tar.bz2
scsi: make eh_eflags persistent
If a failed command is retried and fails again we need to enter SCSI EH, otherwise we will never be able to recover the command. To detect this situation we must not clear scmd->eh_eflags when EH finishes but rather make it persistent throughout the lifetime of the command. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> 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.txt14
1 files changed, 7 insertions, 7 deletions
diff --git a/Documentation/scsi/scsi_eh.txt b/Documentation/scsi/scsi_eh.txt
index 37eca00796ee..4edb9c1cbef5 100644
--- a/Documentation/scsi/scsi_eh.txt
+++ b/Documentation/scsi/scsi_eh.txt
@@ -105,11 +105,14 @@ function
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. If that fails
- Step #3 is taken.
+ 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_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD) is invoked for the
- command. See [1-3] for more information.
+ 3. scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD) is invoked for the
+ command. See [1-4] for more information.
[1-3] Asynchronous command aborts
@@ -263,7 +266,6 @@ scmd->allowed.
3. scmd recovered
ACTION: scsi_eh_finish_cmd() is invoked to EH-finish scmd
- - clear scmd->eh_eflags
- scsi_setup_cmd_retry()
- move from local eh_work_q to local eh_done_q
LOCKING: none
@@ -456,8 +458,6 @@ except for #1 must be implemented by eh_strategy_handler().
- shost->host_failed is zero.
- - Each scmd's eh_eflags field is cleared.
-
- Each scmd is in such a state that scsi_setup_cmd_retry() on the
scmd doesn't make any difference.