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[Qemu-devel] [PATCH 07/11] blockjob: introduce block_job_cancel_async, c
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PATCH 07/11] blockjob: introduce block_job_cancel_async, check iostatus invariants |
Date: |
Wed, 19 Apr 2017 16:42:15 +0200 |
The new functions helps respecting the invariant that the coroutine
is entered with false user_resume, zero pause count and no error
recorded in the iostatus.
Resetting the iostatus is now common to all of block_job_cancel_async,
block_job_user_resume and block_job_iostatus_reset, albeit with slight
differences:
- block_job_cancel_async resets the iostatus, and resumes the job if
there was an error, but the coroutine is not restarted immediately.
For example the caller may continue with a call to block_job_finish_sync.
- block_job_user_resume resets the iostatus. It wants to resume the job
unconditionally, even if there was no error.
- block_job_iostatus_reset doesn't resume the job at all. Maybe that's
a bug but it should be fixed separately.
block_job_iostatus_reset does the least common denominator, so add some
checking but otherwise leave it as the entry point for resetting the
iostatus.
Signed-off-by: Paolo Bonzini <address@hidden>
---
v1->v2: rewritten
blockjob.c | 24 ++++++++++++++++++++----
1 file changed, 20 insertions(+), 4 deletions(-)
diff --git a/blockjob.c b/blockjob.c
index 5906266..1756153 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -304,6 +304,19 @@ static void block_job_completed_single(BlockJob *job)
block_job_unref(job);
}
+static void block_job_cancel_async(BlockJob *job)
+{
+ if (job->iostatus != BLOCK_DEVICE_IO_STATUS_OK) {
+ block_job_iostatus_reset(job);
+ }
+ if (job->user_paused) {
+ /* Do not call block_job_enter here, the caller will handle it. */
+ job->user_paused = false;
+ job->pause_count--;
+ }
+ job->cancelled = true;
+}
+
static void block_job_completed_txn_abort(BlockJob *job)
{
AioContext *ctx;
@@ -328,7 +341,7 @@ static void block_job_completed_txn_abort(BlockJob *job)
* them; this job, however, may or may not be cancelled, depending
* on the caller, so leave it. */
if (other_job != job) {
- other_job->cancelled = true;
+ block_job_cancel_async(other_job);
}
continue;
}
@@ -411,8 +424,8 @@ bool block_job_user_paused(BlockJob *job)
void block_job_user_resume(BlockJob *job)
{
if (job && job->user_paused && job->pause_count > 0) {
- job->user_paused = false;
block_job_iostatus_reset(job);
+ job->user_paused = false;
block_job_resume(job);
}
}
@@ -420,8 +433,7 @@ void block_job_user_resume(BlockJob *job)
void block_job_cancel(BlockJob *job)
{
if (block_job_started(job)) {
- job->cancelled = true;
- block_job_iostatus_reset(job);
+ block_job_cancel_async(job);
block_job_enter(job);
} else {
block_job_completed(job, -ECANCELED);
@@ -765,6 +777,10 @@ void block_job_yield(BlockJob *job)
void block_job_iostatus_reset(BlockJob *job)
{
+ if (job->iostatus == BLOCK_DEVICE_IO_STATUS_OK) {
+ return;
+ }
+ assert(job->user_paused && job->pause_count > 0);
job->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
}
--
2.9.3
[Qemu-devel] [PATCH 03/11] blockjob: introduce block_job_early_fail, Paolo Bonzini, 2017/04/19
[Qemu-devel] [PATCH 04/11] blockjob: introduce block_job_pause/resume_all, Paolo Bonzini, 2017/04/19
[Qemu-devel] [PATCH 08/11] blockjob: group BlockJob transaction functions together, Paolo Bonzini, 2017/04/19
[Qemu-devel] [PATCH 09/11] blockjob: strengthen a bit test-blockjob-txn, Paolo Bonzini, 2017/04/19
[Qemu-devel] [PATCH 07/11] blockjob: introduce block_job_cancel_async, check iostatus invariants,
Paolo Bonzini <=
[Qemu-devel] [PATCH 10/11] blockjob: reorganize block_job_completed_txn_abort, Paolo Bonzini, 2017/04/19
[Qemu-devel] [PATCH 06/11] blockjob: move iostatus reset inside block_job_user_resume, Paolo Bonzini, 2017/04/19
[Qemu-devel] [PATCH 11/11] blockjob: use deferred_to_main_loop to indicate the coroutine has ended, Paolo Bonzini, 2017/04/19
[Qemu-devel] [PATCH 05/11] blockjob: separate monitor and blockjob APIs, Paolo Bonzini, 2017/04/19