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From: Emanuele Giuseppe Esposito <eesposit@redhat.com>
To: qemu-block@nongnu.org
Cc: Kevin Wolf <kwolf@redhat.com>, Fam Zheng <fam@euphon.net>,
	Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>,
	Wen Congyang <wencongyang2@huawei.com>,
	Xie Changlong <xiechanglong.d@gmail.com>,
	Emanuele Giuseppe Esposito <eesposit@redhat.com>,
	Markus Armbruster <armbru@redhat.com>,
	qemu-devel@nongnu.org, Hanna Reitz <hreitz@redhat.com>,
	Stefan Hajnoczi <stefanha@redhat.com>,
	Paolo Bonzini <pbonzini@redhat.com>, John Snow <jsnow@redhat.com>
Subject: [PATCH v4 06/19] jobs: remove aiocontext locks since the functions are under BQL
Date: Fri, 28 Jan 2022 06:50:18 -0500	[thread overview]
Message-ID: <20220128115031.4061565-7-eesposit@redhat.com> (raw)
In-Reply-To: <20220128115031.4061565-1-eesposit@redhat.com>

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 must be taken inside the AioContext
lock, and taking it outside would cause deadlocks.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
 blockdev.c | 4 ----
 job-qmp.c  | 4 ----
 2 files changed, 8 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index 800e95ba54..45a24fee8a 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -3713,15 +3713,11 @@ 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 = block_job_get_aio_context(job);
-        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;
-- 
2.31.1



  parent reply	other threads:[~2022-01-28 12:20 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-28 11:50 [PATCH v4 00/19] job: replace AioContext lock with job_mutex Emanuele Giuseppe Esposito
2022-01-28 11:50 ` [PATCH v4 01/19] job.c: make job_mutex and job_lock/unlock() public Emanuele Giuseppe Esposito
2022-01-28 11:50 ` [PATCH v4 02/19] job.h: categorize fields in struct Job Emanuele Giuseppe Esposito
2022-01-28 11:50 ` [PATCH v4 03/19] job.c: make job_event_* functions static Emanuele Giuseppe Esposito
2022-01-28 11:50 ` [PATCH v4 04/19] job.c: move inner aiocontext lock in callbacks Emanuele Giuseppe Esposito
2022-01-28 11:50 ` [PATCH v4 05/19] aio-wait.h: introduce AIO_WAIT_WHILE_UNLOCKED Emanuele Giuseppe Esposito
2022-01-28 11:50 ` Emanuele Giuseppe Esposito [this message]
2022-01-28 11:50 ` [PATCH v4 07/19] jobs: protect jobs with job_lock/unlock Emanuele Giuseppe Esposito
2022-01-28 11:50 ` [PATCH v4 08/19] jobs: add job lock in find_* functions Emanuele Giuseppe Esposito
2022-01-28 11:50 ` [PATCH v4 09/19] jobs: use job locks also in the unit tests Emanuele Giuseppe Esposito
2022-01-28 11:50 ` [PATCH v4 10/19] job.h: define locked functions Emanuele Giuseppe Esposito
2022-01-28 11:50 ` [PATCH v4 11/19] jobs: document all static functions and add _locked() suffix Emanuele Giuseppe Esposito
2022-01-28 11:50 ` [PATCH v4 12/19] job.h: define unlocked functions Emanuele Giuseppe Esposito
2022-01-28 11:50 ` [PATCH v4 13/19] block/mirror.c: use of job helpers in drivers to avoid TOC/TOU Emanuele Giuseppe Esposito
2022-01-28 11:50 ` [PATCH v4 14/19] blockjob: block_job_get_aio_context is a GS function Emanuele Giuseppe Esposito
2022-01-28 11:50 ` [PATCH v4 15/19] commit and mirror: create new nodes using bdrv_get_aio_context, and not the job aiocontext Emanuele Giuseppe Esposito
2022-01-28 11:50 ` [PATCH v4 16/19] job: detect change of aiocontext within job coroutine Emanuele Giuseppe Esposito
2022-01-31 10:03   ` Emanuele Giuseppe Esposito
2022-01-28 11:50 ` [PATCH v4 17/19] jobs: protect job.aio_context with BQL and job_mutex Emanuele Giuseppe Esposito
2022-01-28 11:50 ` [PATCH v4 18/19] job.c: enable job lock/unlock and remove Aiocontext locks Emanuele Giuseppe Esposito
2022-01-28 11:50 ` [PATCH v4 19/19] block_job_query: remove atomic read Emanuele Giuseppe Esposito

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