Upgrade to 4.4.50-rt62

[kvmfornfv.git] / kernel / Documentation / scsi / scsi_eh.txt

diff --git a/kernel/Documentation/scsi/scsi_eh.txt b/kernel/Documentation/scsi/scsi_eh.txt
index 8638f61..37eca00 100644 (file)
--- a/kernel/Documentation/scsi/scsi_eh.txt
+++ b/kernel/Documentation/scsi/scsi_eh.txt
@@ -263,19 +263,23 @@ scmd->allowed.
 
  3. scmd recovered
     ACTION: scsi_eh_finish_cmd() is invoked to EH-finish scmd
-       - shost->host_failed--
        - clear scmd->eh_eflags
        - scsi_setup_cmd_retry()
        - move from local eh_work_q to local eh_done_q
     LOCKING: none
+    CONCURRENCY: at most one thread per separate eh_work_q to
+                keep queue manipulation lockless
 
  4. EH completes
     ACTION: scsi_eh_flush_done_q() retries scmds or notifies upper
-           layer of failure.
+           layer of failure. May be called concurrently but must have
+           a no more than one thread per separate eh_work_q to
+           manipulate the queue locklessly
        - scmd is removed from eh_done_q and scmd->eh_entry is cleared
        - if retry is necessary, scmd is requeued using
           scsi_queue_insert()
        - otherwise, scsi_finish_command() is invoked for scmd
+       - zero shost->host_failed
     LOCKING: queue or finish function performs appropriate locking