diff options
author | John Snow <jsnow@redhat.com> | 2018-03-10 03:27:35 -0500 |
---|---|---|
committer | Kevin Wolf <kwolf@redhat.com> | 2018-03-19 12:01:24 +0100 |
commit | 3925cd3bc7bdc82b7889fd97e7cad52dfee5e8a6 (patch) | |
tree | 494c3b8344b2fec54235cdf1eefef1f83bcb9691 /blockjob.c | |
parent | e0cf03647aa6ba9f08f98d634d8fac46aec822fb (diff) | |
download | qemu-3925cd3bc7bdc82b7889fd97e7cad52dfee5e8a6.zip qemu-3925cd3bc7bdc82b7889fd97e7cad52dfee5e8a6.tar.gz qemu-3925cd3bc7bdc82b7889fd97e7cad52dfee5e8a6.tar.bz2 |
blockjobs: add NULL state
Add a new state that specifically demarcates when we begin to permanently
demolish a job after it has performed all work. This makes the transition
explicit in the STM table and highlights conditions under which a job may
be demolished.
Alongside this state, add a new helper command "block_job_decommission",
which transitions to the NULL state and puts down our implicit reference.
This separates instances in the code for "block_job_unref" which merely
undo a matching "block_job_ref" with instances intended to initiate the
full destruction of the object.
This decommission action also sets a number of fields to make sure that
block internals or external users that are holding a reference to a job
to see when it "finishes" are convinced that the job object is "done."
This is necessary, for instance, to do a block_job_cancel_sync on a
created object which will not make any progress.
Now, all jobs must go through block_job_decommission prior to being
freed, giving us start-to-finish state machine coverage for jobs.
Transitions:
Created -> Null: Early failure event before the job is started
Concluded -> Null: Standard transition.
Verbs:
None. This should not ever be visible to the monitor.
+---------+
|UNDEFINED|
+--+------+
|
+--v----+
+---------+CREATED+------------------+
| +--+----+ |
| | |
| +--v----+ +------+ |
+---------+RUNNING<----->PAUSED| |
| +--+-+--+ +------+ |
| | | |
| | +------------------+ |
| | | |
| +--v--+ +-------+ | |
+---------+READY<------->STANDBY| | |
| +--+--+ +-------+ | |
| | | |
+--v-----+ +--v------+ | |
|ABORTING+--->CONCLUDED<-------------+ |
+--------+ +--+------+ |
| |
+--v-+ |
|NULL<---------------------+
+----+
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'blockjob.c')
-rw-r--r-- | blockjob.c | 50 |
1 files changed, 32 insertions, 18 deletions
@@ -44,24 +44,25 @@ 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 */ - /* U: */ [BLOCK_JOB_STATUS_UNDEFINED] = {0, 1, 0, 0, 0, 0, 0, 0}, - /* C: */ [BLOCK_JOB_STATUS_CREATED] = {0, 0, 1, 0, 0, 0, 1, 0}, - /* R: */ [BLOCK_JOB_STATUS_RUNNING] = {0, 0, 0, 1, 1, 0, 1, 1}, - /* P: */ [BLOCK_JOB_STATUS_PAUSED] = {0, 0, 1, 0, 0, 0, 0, 0}, - /* Y: */ [BLOCK_JOB_STATUS_READY] = {0, 0, 0, 0, 0, 1, 1, 1}, - /* S: */ [BLOCK_JOB_STATUS_STANDBY] = {0, 0, 0, 0, 1, 0, 0, 0}, - /* X: */ [BLOCK_JOB_STATUS_ABORTING] = {0, 0, 0, 0, 0, 0, 0, 1}, - /* E: */ [BLOCK_JOB_STATUS_CONCLUDED] = {0, 0, 0, 0, 0, 0, 0, 0}, + /* 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, 0, 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}, }; bool BlockJobVerbTable[BLOCK_JOB_VERB__MAX][BLOCK_JOB_STATUS__MAX] = { - /* U, C, R, P, Y, S, X, E */ - [BLOCK_JOB_VERB_CANCEL] = {0, 1, 1, 1, 1, 1, 0, 0}, - [BLOCK_JOB_VERB_PAUSE] = {0, 1, 1, 1, 1, 1, 0, 0}, - [BLOCK_JOB_VERB_RESUME] = {0, 1, 1, 1, 1, 1, 0, 0}, - [BLOCK_JOB_VERB_SET_SPEED] = {0, 1, 1, 1, 1, 1, 0, 0}, - [BLOCK_JOB_VERB_COMPLETE] = {0, 0, 0, 0, 1, 0, 0, 0}, + /* 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}, }; static void block_job_state_transition(BlockJob *job, BlockJobStatus s1) @@ -225,6 +226,7 @@ static void block_job_detach_aio_context(void *opaque); void block_job_unref(BlockJob *job) { if (--job->refcnt == 0) { + assert(job->status == BLOCK_JOB_STATUS_NULL); BlockDriverState *bs = blk_bs(job->blk); QLIST_REMOVE(job, job_list); bs->job = NULL; @@ -378,6 +380,17 @@ void block_job_start(BlockJob *job) bdrv_coroutine_enter(blk_bs(job->blk), job->co); } +static void block_job_decommission(BlockJob *job) +{ + assert(job); + job->completed = true; + job->busy = false; + job->paused = false; + job->deferred_to_main_loop = true; + block_job_state_transition(job, BLOCK_JOB_STATUS_NULL); + block_job_unref(job); +} + static void block_job_conclude(BlockJob *job) { block_job_state_transition(job, BLOCK_JOB_STATUS_CONCLUDED); @@ -424,7 +437,7 @@ static void block_job_completed_single(BlockJob *job) QLIST_REMOVE(job, txn_list); block_job_txn_unref(job->txn); block_job_conclude(job); - block_job_unref(job); + block_job_decommission(job); } static void block_job_cancel_async(BlockJob *job) @@ -817,7 +830,7 @@ void *block_job_create(const char *job_id, const BlockJobDriver *driver, block_job_set_speed(job, speed, &local_err); if (local_err) { - block_job_unref(job); + block_job_early_fail(job); error_propagate(errp, local_err); return NULL; } @@ -851,7 +864,8 @@ void block_job_pause_all(void) void block_job_early_fail(BlockJob *job) { - block_job_unref(job); + assert(job->status == BLOCK_JOB_STATUS_CREATED); + block_job_decommission(job); } void block_job_completed(BlockJob *job, int ret) |