On Fri, Sep 30, 2016 at 06:00:41PM -0400, John Snow wrote:
BlockJobs will begin hiding their state in preparation for some
refactorings anyway, so let's internalize the user_pause mechanism
instead of leaving it to callers to correctly manage.
Signed-off-by: John Snow <address@hidden>
---
block/io.c | 2 +-
blockdev.c | 10 ++++------
blockjob.c | 16 ++++++++++++----
include/block/blockjob.h | 11 ++++++++++-
4 files changed, 27 insertions(+), 12 deletions(-)
diff --git a/block/io.c b/block/io.c
index fdf7080..868b065 100644
--- a/block/io.c
+++ b/block/io.c
@@ -291,7 +291,7 @@ void bdrv_drain_all(void)
AioContext *aio_context = blk_get_aio_context(job->blk);
aio_context_acquire(aio_context);
- block_job_pause(job);
+ block_job_pause(job, false);
Hmm. Maybe semantically, an enum might work better here than a bool. When
I see "block_job_pause(job, false)", it reads like you just un-paused the
job, rather than paused it with some contextual info. Perhaps
JOB_USER_PAUSE and JOB_SYS_PAUSE (or just JOB_USER and JOB_SYS)?
aio_context_release(aio_context);
}
diff --git a/blockdev.c b/blockdev.c
index 03200e7..268452f 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -3629,7 +3629,7 @@ void qmp_block_job_cancel(const char *device,
force = false;
}
- if (job->user_paused && !force) {
+ if (block_job_paused(job) && !force) {
error_setg(errp, "The block job for device '%s' is currently paused",
device);
goto out;
@@ -3646,13 +3646,12 @@ void qmp_block_job_pause(const char *device, Error
**errp)
AioContext *aio_context;
BlockJob *job = find_block_job(device, &aio_context, errp);
- if (!job || job->user_paused) {
+ if (!job || block_job_paused(job)) {
return;
}
- job->user_paused = true;
trace_qmp_block_job_pause(job);
- block_job_pause(job);
+ block_job_pause(job, true);
aio_context_release(aio_context);
}
@@ -3661,11 +3660,10 @@ void qmp_block_job_resume(const char *device, Error
**errp)
AioContext *aio_context;
BlockJob *job = find_block_job(device, &aio_context, errp);
- if (!job || !job->user_paused) {
+ if (!job || !block_job_paused(job)) {
return;
}
- job->user_paused = false;
trace_qmp_block_job_resume(job);
block_job_iostatus_reset(job);
block_job_resume(job);
diff --git a/blockjob.c b/blockjob.c
index 6a300ba..2a35f50 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -104,7 +104,7 @@ static void block_job_detach_aio_context(void *opaque)
/* In case the job terminates during aio_poll()... */
block_job_ref(job);
- block_job_pause(job);
+ block_job_pause(job, false);
if (!job->paused) {
/* If job is !job->busy this kicks it into the next pause point. */
@@ -343,9 +343,12 @@ void block_job_complete(BlockJob *job, Error **errp)
job->driver->complete(job, errp);
}
-void block_job_pause(BlockJob *job)
+void block_job_pause(BlockJob *job, bool user)
{
job->pause_count++;
+ if (user) {
+ job->user_paused = true;
+ }
}
static bool block_job_should_pause(BlockJob *job)
@@ -353,6 +356,11 @@ static bool block_job_should_pause(BlockJob *job)
return job->pause_count > 0;
}
+bool block_job_paused(BlockJob *job)
I think a more apt name for this would be "block_job_user_paused()", because
it doesn't tell if the job is paused per se, but only if it is paused by a
user.
+{
+ return job ? job->user_paused : 0;
+}
+
void coroutine_fn block_job_pause_point(BlockJob *job)
{
if (!block_job_should_pause(job)) {
@@ -386,6 +394,7 @@ void block_job_resume(BlockJob *job)
if (job->pause_count) {
return;
}
+ job->user_paused = false;
At first I was thinking block_job_resume() would need a way of knowing if it
was a user resume, similar to block_job_pause(). But I guess not... if the
user paused it, then job->pause_count should always be > 0, I think.
But wait...could we ever get into a state where something like this happens:
block_job_pause(job, true); /* user paused */
[...]
block_job_pause(job, false); /* system paused */
[...]
block_job_resume(job); /* user resumes */
[...] /* job->user_paused is still true, although it shouldn't be */
block_job_resume(job); /* system resumes */
/* now job->user_paused is false */
block_job_enter(job);
}
@@ -592,8 +601,7 @@ BlockErrorAction block_job_error_action(BlockJob *job,
BlockdevOnError on_err,
action, &error_abort);
if (action == BLOCK_ERROR_ACTION_STOP) {
/* make the pause user visible, which will be resumed from QMP. */
- job->user_paused = true;
- block_job_pause(job);
+ block_job_pause(job, true);
block_job_iostatus_set_err(job, error);
}
return action;
diff --git a/include/block/blockjob.h b/include/block/blockjob.h
index 4ddb4ae..081f6c2 100644
--- a/include/block/blockjob.h
+++ b/include/block/blockjob.h
@@ -347,10 +347,19 @@ void coroutine_fn block_job_pause_point(BlockJob *job);
/**
* block_job_pause:
* @job: The job to be paused.
+ * @user: Requested explicitly via user?
*
* Asynchronously pause the specified job.
*/
-void block_job_pause(BlockJob *job);
+void block_job_pause(BlockJob *job, bool user);
+
+/**
+ * block_job_paused:
+ * @job: The job to query.
+ *
+ * Returns true if the job is user-paused.
+ */
+bool block_job_paused(BlockJob *job);
/**
* block_job_resume:
--
2.7.4