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[PATCH v4 00/19] job: replace AioContext lock with job_mutex
From: |
Emanuele Giuseppe Esposito |
Subject: |
[PATCH v4 00/19] job: replace AioContext lock with job_mutex |
Date: |
Fri, 28 Jan 2022 06:50:12 -0500 |
In this series, we want to remove the AioContext lock and instead
use the already existent job_mutex to protect the job structures
and list. This is part of the work to get rid of AioContext lock
usage in favour of smaller granularity locks.
In order to simplify reviewer's job, job lock/unlock functions and
macros are added as empty prototypes (nop) in patch 1.
They are converted to use the actual job mutex only in the last
patch. In this way we can freely create locking sections
without worrying about deadlocks with the aiocontext lock.
Patch 2 defines what fields in the job structure need protection.
Patches 3-6 are in preparation to the job locks, moving functions
from global to static and introducing helpers.
Patch 7-9 introduce the (nop) job lock into the job API and
its users, and patches 10-13 categorize respectively locked and unlocked
functions in the job API.
Patches 14-17 take care of protecting job->aio_context, and
finally patch 18 makes the prototypes in patch 1 use the
job_mutex and removes all aiocontext lock at the same time.
Tested this series by running unit tests, qemu-iotests and qtests
(x86_64).
This serie is based on my previous series "block layer: split
block APIs in global state and I/O" and also depends on the new
converted tests 141 and 185.
Based-on: <20220121170544.2049944-1-eesposit@redhat.com>
---
v4:
* move "protected by job_mutex" from patch 2 to 15, where the job_mutex is
actually added.
* s/aio_co_enter/aio_co_schedule in job.c, and adjust tests accordingly.
* remove job_get_aio_context, add job_set_aio_context. Use "fake rwlock"
to protect job->aiocontext.
* get rid of useless getters method, namely:
job_get_status
job_get_pause_count
job_get_paused
job_get_busy
They are all used only by tests, and such getter is pretty useless.
Replace with job_lock(); assert(); job_unlock();
* use job lock macros instead of job lock/unlock in unit tests.
* convert also blockjob functions to have _locked
* put the job_lock/unlock patches before the _locked ones
* replace aio_co_enter in job.c and detect change of context
v3:
* add "_locked" suffix to the functions called under job_mutex lock
* rename _job_lock in real_job_lock
* job_mutex is now public, and drivers like monitor use it directly
* introduce and protect job_get_aio_context
* remove mirror-specific APIs and just use WITH_JOB_GUARD
* more extensive use of WITH_JOB_GUARD and JOB_LOCK_GUARD
RFC v2:
* use JOB_LOCK_GUARD and WITH_JOB_LOCK_GUARD
* mu(u)ltiple typos in commit messages
* job API split patches are sent separately in another series
* use of empty job_{lock/unlock} and JOB_LOCK_GUARD/WITH_JOB_LOCK_GUARD
to avoid deadlocks and simplify the reviewer job
* move patch 11 (block_job_query: remove atomic read) as last
Emanuele Giuseppe Esposito (18):
job.c: make job_mutex and job_lock/unlock() public
job.h: categorize fields in struct Job
job.c: make job_event_* functions static
job.c: move inner aiocontext lock in callbacks
aio-wait.h: introduce AIO_WAIT_WHILE_UNLOCKED
jobs: remove aiocontext locks since the functions are under BQL
jobs: protect jobs with job_lock/unlock
jobs: add job lock in find_* functions
jobs: use job locks also in the unit tests
job.h: define locked functions
jobs: document all static functions and add _locked() suffix
job.h: define unlocked functions
block/mirror.c: use of job helpers in drivers to avoid TOC/TOU
blockjob: block_job_get_aio_context is a GS function
commit and mirror: create new nodes using bdrv_get_aio_context, and
not the job aiocontext
jobs: protect job.aio_context with BQL and job_mutex
job.c: enable job lock/unlock and remove Aiocontext locks
block_job_query: remove atomic read
Paolo Bonzini (1):
job: detect change of aiocontext within job coroutine
block.c | 19 +-
block/backup.c | 4 +-
block/commit.c | 4 +-
block/mirror.c | 21 +-
block/replication.c | 10 +-
blockdev.c | 124 +++---
blockjob.c | 133 ++++---
include/block/aio-wait.h | 15 +-
include/block/blockjob.h | 44 +-
include/qemu/job.h | 305 ++++++++++----
job-qmp.c | 74 ++--
job.c | 661 +++++++++++++++++++------------
monitor/qmp-cmds.c | 7 +-
qemu-img.c | 41 +-
tests/unit/test-bdrv-drain.c | 80 ++--
tests/unit/test-block-iothread.c | 8 +-
tests/unit/test-blockjob-txn.c | 32 +-
tests/unit/test-blockjob.c | 113 ++++--
18 files changed, 1027 insertions(+), 668 deletions(-)
--
2.31.1
- [PATCH v4 00/19] job: replace AioContext lock with job_mutex,
Emanuele Giuseppe Esposito <=
- [PATCH v4 01/19] job.c: make job_mutex and job_lock/unlock() public, Emanuele Giuseppe Esposito, 2022/01/28
- [PATCH v4 02/19] job.h: categorize fields in struct Job, Emanuele Giuseppe Esposito, 2022/01/28
- [PATCH v4 04/19] job.c: move inner aiocontext lock in callbacks, Emanuele Giuseppe Esposito, 2022/01/28
- [PATCH v4 03/19] job.c: make job_event_* functions static, Emanuele Giuseppe Esposito, 2022/01/28
- [PATCH v4 05/19] aio-wait.h: introduce AIO_WAIT_WHILE_UNLOCKED, Emanuele Giuseppe Esposito, 2022/01/28
- [PATCH v4 07/19] jobs: protect jobs with job_lock/unlock, Emanuele Giuseppe Esposito, 2022/01/28
- [PATCH v4 14/19] blockjob: block_job_get_aio_context is a GS function, Emanuele Giuseppe Esposito, 2022/01/28
- [PATCH v4 06/19] jobs: remove aiocontext locks since the functions are under BQL, Emanuele Giuseppe Esposito, 2022/01/28
- [PATCH v4 09/19] jobs: use job locks also in the unit tests, Emanuele Giuseppe Esposito, 2022/01/28
- [PATCH v4 16/19] job: detect change of aiocontext within job coroutine, Emanuele Giuseppe Esposito, 2022/01/28