Hmm. subject looks like it's safe to remove aiocontext locks from any qmp
command?
For example, commit 91005a495e228eb added aiocontext locks back to qmp bitmap
add/remove commands because otherwise they crashed.
So, I'm not sure that being under BQL is enough to drop aiocontext locking..
29.10.2021 19:39, Emanuele Giuseppe Esposito wrote:
In preparation to the job_lock/unlock patch, remove these
aiocontext locks.
The main reason these two locks are removed here is because
they are inside a loop iterating on the jobs list. Once the
job_lock is added, it will have to protect the whole loop,
wrapping also the aiocontext acquire/release.
We don't want this, as job_lock can only be *wrapped by*
the aiocontext lock, and not vice-versa, to avoid deadlocks.
Signed-off-by: Emanuele Giuseppe Esposito <eespo...@redhat.com>
---
blockdev.c | 4 ----
job-qmp.c | 4 ----
2 files changed, 8 deletions(-)
diff --git a/blockdev.c b/blockdev.c
index d9bf842a81..67b55eec11 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -3719,15 +3719,11 @@ BlockJobInfoList *qmp_query_block_jobs(Error **errp)
for (job = block_job_next(NULL); job; job = block_job_next(job)) {
BlockJobInfo *value;
- AioContext *aio_context;
if (block_job_is_internal(job)) {
continue;
}
- aio_context = blk_get_aio_context(job->blk);
- aio_context_acquire(aio_context);
value = block_job_query(job, errp);
- aio_context_release(aio_context);
if (!value) {
qapi_free_BlockJobInfoList(head);
return NULL;
diff --git a/job-qmp.c b/job-qmp.c
index 829a28aa70..a6774aaaa5 100644
--- a/job-qmp.c
+++ b/job-qmp.c
@@ -173,15 +173,11 @@ JobInfoList *qmp_query_jobs(Error **errp)
for (job = job_next(NULL); job; job = job_next(job)) {
JobInfo *value;
- AioContext *aio_context;
if (job_is_internal(job)) {
continue;
}
- aio_context = job->aio_context;
- aio_context_acquire(aio_context);
value = job_query_single(job, errp);
- aio_context_release(aio_context);
if (!value) {
qapi_free_JobInfoList(head);
return NULL;
--
Best regards,
Vladimir
