blockjobs: add waiting status

For jobs that are stuck waiting on others in a transaction, it would
be nice to know that they are no longer "running" in that sense, but
instead are waiting on other jobs in the transaction.

Jobs that are "waiting" in this sense cannot be meaningfully altered
any longer as they have left their running loop. The only meaningful
user verb for jobs in this state is "cancel," which will cancel the
whole transaction, too.

Transitions:
Running -> Waiting:   Normal transition.
Ready   -> Waiting:   Normal transition.
Waiting -> Aborting:  Transactional cancellation.
Waiting -> Concluded: Normal transition.

Removed Transitions:
Running -> Concluded: Jobs must go to WAITING first.
Ready   -> Concluded: Jobs must go to WAITING first.

Verbs:
Cancel: Can be applied to WAITING jobs.

             +---------+
             |UNDEFINED|
             +--+------+
                |
             +--v----+
   +---------+CREATED+-----------------+
   |         +--+----+                 |
   |            |                      |
   |         +--v----+     +------+    |
   +---------+RUNNING<----->PAUSED|    |
   |         +--+-+--+     +------+    |
   |            | |                    |
   |            | +------------------+ |
   |            |                    | |
   |         +--v--+       +-------+ | |
   +---------+READY<------->STANDBY| | |
   |         +--+--+       +-------+ | |
   |            |                    | |
   |         +--v----+               | |
   +---------+WAITING<---------------+ |
   |         +--+----+                 |
   |            |                      |
+--v-----+   +--v------+               |
|ABORTING+--->CONCLUDED|               |
+--------+   +--+------+               |
                |                      |
             +--v-+                    |
             |NULL<--------------------+
             +----+

Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

diff --git a/blockjob.c b/blockjob.c
index 3c1580e1ef527aab1b98dcbfce82a730a5874d1b..e7dd6e12548af4125a7fb9a7d1ed4aef79fc82a0 100644 (file)
--- a/blockjob.c
+++ b/blockjob.c
@@ -44,26 +44,27 @@ static QemuMutex block_job_mutex;
 
 /* BlockJob State Transition Table */
 bool BlockJobSTT[BLOCK_JOB_STATUS__MAX][BLOCK_JOB_STATUS__MAX] = {
-                                          /* U, C, R, P, Y, S, X, E, N */
-    /* U: */ [BLOCK_JOB_STATUS_UNDEFINED] = {0, 1, 0, 0, 0, 0, 0, 0, 0},
-    /* C: */ [BLOCK_JOB_STATUS_CREATED]   = {0, 0, 1, 0, 0, 0, 1, 0, 1},
-    /* R: */ [BLOCK_JOB_STATUS_RUNNING]   = {0, 0, 0, 1, 1, 0, 1, 1, 0},
-    /* P: */ [BLOCK_JOB_STATUS_PAUSED]    = {0, 0, 1, 0, 0, 0, 0, 0, 0},
-    /* Y: */ [BLOCK_JOB_STATUS_READY]     = {0, 0, 0, 0, 0, 1, 1, 1, 0},
-    /* S: */ [BLOCK_JOB_STATUS_STANDBY]   = {0, 0, 0, 0, 1, 0, 0, 0, 0},
-    /* X: */ [BLOCK_JOB_STATUS_ABORTING]  = {0, 0, 0, 0, 0, 0, 1, 1, 0},
-    /* E: */ [BLOCK_JOB_STATUS_CONCLUDED] = {0, 0, 0, 0, 0, 0, 0, 0, 1},
-    /* N: */ [BLOCK_JOB_STATUS_NULL]      = {0, 0, 0, 0, 0, 0, 0, 0, 0},
+                                          /* U, C, R, P, Y, S, W, X, E, N */
+    /* U: */ [BLOCK_JOB_STATUS_UNDEFINED] = {0, 1, 0, 0, 0, 0, 0, 0, 0, 0},
+    /* C: */ [BLOCK_JOB_STATUS_CREATED]   = {0, 0, 1, 0, 0, 0, 0, 1, 0, 1},
+    /* R: */ [BLOCK_JOB_STATUS_RUNNING]   = {0, 0, 0, 1, 1, 0, 1, 1, 0, 0},
+    /* P: */ [BLOCK_JOB_STATUS_PAUSED]    = {0, 0, 1, 0, 0, 0, 0, 0, 0, 0},
+    /* Y: */ [BLOCK_JOB_STATUS_READY]     = {0, 0, 0, 0, 0, 1, 1, 1, 0, 0},
+    /* S: */ [BLOCK_JOB_STATUS_STANDBY]   = {0, 0, 0, 0, 1, 0, 0, 0, 0, 0},
+    /* W: */ [BLOCK_JOB_STATUS_WAITING]   = {0, 0, 0, 0, 0, 0, 0, 1, 1, 0},
+    /* X: */ [BLOCK_JOB_STATUS_ABORTING]  = {0, 0, 0, 0, 0, 0, 0, 1, 1, 0},
+    /* E: */ [BLOCK_JOB_STATUS_CONCLUDED] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 1},
+    /* N: */ [BLOCK_JOB_STATUS_NULL]      = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
 };
 
 bool BlockJobVerbTable[BLOCK_JOB_VERB__MAX][BLOCK_JOB_STATUS__MAX] = {
-                                          /* U, C, R, P, Y, S, X, E, N */
-    [BLOCK_JOB_VERB_CANCEL]               = {0, 1, 1, 1, 1, 1, 0, 0, 0},
-    [BLOCK_JOB_VERB_PAUSE]                = {0, 1, 1, 1, 1, 1, 0, 0, 0},
-    [BLOCK_JOB_VERB_RESUME]               = {0, 1, 1, 1, 1, 1, 0, 0, 0},
-    [BLOCK_JOB_VERB_SET_SPEED]            = {0, 1, 1, 1, 1, 1, 0, 0, 0},
-    [BLOCK_JOB_VERB_COMPLETE]             = {0, 0, 0, 0, 1, 0, 0, 0, 0},
-    [BLOCK_JOB_VERB_DISMISS]              = {0, 0, 0, 0, 0, 0, 0, 1, 0},
+                                          /* U, C, R, P, Y, S, W, X, E, N */
+    [BLOCK_JOB_VERB_CANCEL]               = {0, 1, 1, 1, 1, 1, 1, 0, 0, 0},
+    [BLOCK_JOB_VERB_PAUSE]                = {0, 1, 1, 1, 1, 1, 0, 0, 0, 0},
+    [BLOCK_JOB_VERB_RESUME]               = {0, 1, 1, 1, 1, 1, 0, 0, 0, 0},
+    [BLOCK_JOB_VERB_SET_SPEED]            = {0, 1, 1, 1, 1, 1, 0, 0, 0, 0},
+    [BLOCK_JOB_VERB_COMPLETE]             = {0, 0, 0, 0, 1, 0, 0, 0, 0, 0},
+    [BLOCK_JOB_VERB_DISMISS]              = {0, 0, 0, 0, 0, 0, 0, 0, 1, 0},
 };
 
 static void block_job_state_transition(BlockJob *job, BlockJobStatus s1)
@@ -596,6 +597,8 @@ static void block_job_completed_txn_success(BlockJob *job)
     BlockJob *other_job;
     int rc = 0;
 
+    block_job_state_transition(job, BLOCK_JOB_STATUS_WAITING);
+
     /*
      * Successful completion, see if there are other running jobs in this
      * txn.

diff --git a/qapi/block-core.json b/qapi/block-core.json
index afb2e63fa646a1700c2bf1c25a0fb353095c465a..46a0a832546d9187a1a78dd7200a173978960ef4 100644 (file)
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -1001,6 +1001,10 @@
 # @standby: The job is ready, but paused. This is nearly identical to @paused.
 #           The job may return to @ready or otherwise be canceled.
 #
+# @waiting: The job is waiting for other jobs in the transaction to converge
+#           to the waiting state. This status will likely not be visible for
+#           the last job in a transaction.
+#
 # @aborting: The job is in the process of being aborted, and will finish with
 #            an error. The job will afterwards report that it is @concluded.
 #            This status may not be visible to the management process.
@@ -1015,7 +1019,7 @@
 ##
 { 'enum': 'BlockJobStatus',
   'data': ['undefined', 'created', 'running', 'paused', 'ready', 'standby',
-           'aborting', 'concluded', 'null' ] }
+           'waiting', 'aborting', 'concluded', 'null' ] }
 
 ##
 # @BlockJobInfo: