From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
To: Emanuele Giuseppe Esposito <eesposit@redhat.com>, qemu-block@nongnu.org
Cc: John Snow <jsnow@redhat.com>, Kevin Wolf <kwolf@redhat.com>,
Max Reitz <mreitz@redhat.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Stefan Hajnoczi <stefanha@redhat.com>,
qemu-devel@nongnu.org
Subject: Re: [PATCH v2 5/7] block-copy: add QemuMutex lock for BlockCopyCallState list
Date: Thu, 20 May 2021 18:30:19 +0300 [thread overview]
Message-ID: <e1170527-29de-0eda-9f66-399e12923bca@virtuozzo.com> (raw)
In-Reply-To: <20210518100757.31243-6-eesposit@redhat.com>
18.05.2021 13:07, Emanuele Giuseppe Esposito wrote:
> As for BlockCopyTask, add a lock to protect BlockCopyCallState
> ret and sleep_state fields. Also move ret, finished and cancelled
> in the OUT fields of BlockCopyCallState.
>
> Here a QemuMutex is used to protect QemuCoSleep field, since it
> can be concurrently invoked also from outside threads.
>
> .finished, .cancelled and reads to .ret and .error_is_read will be
> protected in the following patch.
>
> .sleep state is handled in the series "coroutine: new sleep/wake API"
Could we live with one mutex for all needs? Why to add one more?
>
> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
> ---
> block/block-copy.c | 27 +++++++++++++++++++--------
> 1 file changed, 19 insertions(+), 8 deletions(-)
>
> diff --git a/block/block-copy.c b/block/block-copy.c
> index 3a949fab64..d5ed5932b0 100644
> --- a/block/block-copy.c
> +++ b/block/block-copy.c
> @@ -55,13 +55,14 @@ typedef struct BlockCopyCallState {
> QLIST_ENTRY(BlockCopyCallState) list;
>
> /* State */
> - int ret;
> bool finished;
> - QemuCoSleep sleep;
> - bool cancelled;
> + QemuCoSleep sleep; /* TODO: protect API with a lock */
>
> /* OUT parameters */
> + bool cancelled;
> + /* Fields protected by calls_lock in BlockCopyState */
> bool error_is_read;
> + int ret;
> } BlockCopyCallState;
>
> typedef struct BlockCopyTask {
> @@ -110,6 +111,7 @@ typedef struct BlockCopyState {
> BlockCopyMethod method;
> CoMutex tasks_lock;
> QLIST_HEAD(, BlockCopyTask) tasks; /* All tasks from all block-copy calls */
> + QemuMutex calls_lock;
> QLIST_HEAD(, BlockCopyCallState) calls;
> /* State fields that use a thread-safe API */
> BdrvDirtyBitmap *copy_bitmap;
> @@ -289,6 +291,7 @@ void block_copy_state_free(BlockCopyState *s)
> }
>
> ratelimit_destroy(&s->rate_limit);
> + qemu_mutex_destroy(&s->calls_lock);
> bdrv_release_dirty_bitmap(s->copy_bitmap);
> shres_destroy(s->mem);
> g_free(s);
> @@ -349,6 +352,7 @@ BlockCopyState *block_copy_state_new(BdrvChild *source, BdrvChild *target,
>
> ratelimit_init(&s->rate_limit);
> qemu_co_mutex_init(&s->tasks_lock);
> + qemu_mutex_init(&s->calls_lock);
> QLIST_INIT(&s->tasks);
> QLIST_INIT(&s->calls);
>
> @@ -492,11 +496,14 @@ static coroutine_fn int block_copy_task_entry(AioTask *task)
>
> ret = block_copy_do_copy(t->s, t->offset, t->bytes, t->zeroes,
> &error_is_read);
> - if (ret < 0 && !t->call_state->ret) {
> - t->call_state->ret = ret;
> - t->call_state->error_is_read = error_is_read;
> - } else {
> - progress_work_done(t->s->progress, t->bytes);
> +
> + WITH_QEMU_LOCK_GUARD(&t->s->calls_lock) {
> + if (ret < 0 && !t->call_state->ret) {
> + t->call_state->ret = ret;
> + t->call_state->error_is_read = error_is_read;
> + } else {
> + progress_work_done(t->s->progress, t->bytes);
> + }
> }
> co_put_to_shres(t->s->mem, t->bytes);
> block_copy_task_end(t, ret);
> @@ -740,7 +747,9 @@ static int coroutine_fn block_copy_common(BlockCopyCallState *call_state)
> {
> int ret;
>
> + qemu_mutex_lock(&call_state->s->calls_lock);
> QLIST_INSERT_HEAD(&call_state->s->calls, call_state, list);
> + qemu_mutex_unlock(&call_state->s->calls_lock);
>
> do {
> ret = block_copy_dirty_clusters(call_state);
> @@ -767,7 +776,9 @@ static int coroutine_fn block_copy_common(BlockCopyCallState *call_state)
> call_state->cb(call_state->cb_opaque);
> }
>
> + qemu_mutex_lock(&call_state->s->calls_lock);
> QLIST_REMOVE(call_state, list);
> + qemu_mutex_unlock(&call_state->s->calls_lock);
>
> return ret;
> }
>
--
Best regards,
Vladimir
next prev parent reply other threads:[~2021-05-20 15:33 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-18 10:07 [PATCH v2 0/7] block-copy: protect block-copy internal structures Emanuele Giuseppe Esposito
2021-05-18 10:07 ` [PATCH v2 1/7] block-copy: streamline choice of copy_range vs. read/write Emanuele Giuseppe Esposito
2021-05-20 14:42 ` Vladimir Sementsov-Ogievskiy
2021-05-20 15:06 ` Emanuele Giuseppe Esposito
2021-05-20 15:24 ` Vladimir Sementsov-Ogievskiy
2021-05-21 15:10 ` Paolo Bonzini
2021-05-21 15:48 ` Vladimir Sementsov-Ogievskiy
2021-05-21 16:43 ` Paolo Bonzini
2021-05-21 17:51 ` Vladimir Sementsov-Ogievskiy
2021-05-27 8:20 ` Stefan Hajnoczi
2021-05-27 19:04 ` Paolo Bonzini
2021-05-18 10:07 ` [PATCH v2 2/7] block-copy: improve documentation of BlockCopyTask and BlockCopyState types and functions Emanuele Giuseppe Esposito
2021-05-20 15:00 ` Vladimir Sementsov-Ogievskiy
2021-05-20 15:15 ` Emanuele Giuseppe Esposito
2021-05-18 10:07 ` [PATCH v2 3/7] block-copy: move progress_set_remaining in block_copy_task_end Emanuele Giuseppe Esposito
2021-05-20 15:03 ` Vladimir Sementsov-Ogievskiy
2021-05-18 10:07 ` [PATCH v2 4/7] block-copy: add a CoMutex to the BlockCopyTask list Emanuele Giuseppe Esposito
2021-05-20 15:19 ` Vladimir Sementsov-Ogievskiy
2021-05-25 10:07 ` Emanuele Giuseppe Esposito
2021-05-25 10:25 ` Vladimir Sementsov-Ogievskiy
2021-05-26 14:58 ` Paolo Bonzini
2021-05-26 16:13 ` Vladimir Sementsov-Ogievskiy
2021-05-27 9:07 ` Stefan Hajnoczi
2021-05-18 10:07 ` [PATCH v2 5/7] block-copy: add QemuMutex lock for BlockCopyCallState list Emanuele Giuseppe Esposito
2021-05-20 15:30 ` Vladimir Sementsov-Ogievskiy [this message]
2021-05-21 15:01 ` Paolo Bonzini
2021-05-25 10:58 ` Emanuele Giuseppe Esposito
2021-05-26 14:49 ` Paolo Bonzini
2021-05-28 10:53 ` Paolo Bonzini
2021-05-18 10:07 ` [PATCH v2 6/7] block-copy: atomic .cancelled and .finished fields in BlockCopyCallState Emanuele Giuseppe Esposito
2021-05-20 15:34 ` Vladimir Sementsov-Ogievskiy
2021-05-21 15:02 ` Paolo Bonzini
2021-05-21 15:53 ` Vladimir Sementsov-Ogievskiy
2021-05-21 15:56 ` Vladimir Sementsov-Ogievskiy
2021-05-21 16:47 ` Paolo Bonzini
2021-05-18 10:07 ` [PATCH v2 7/7] block-copy: protect BlockCopyState .method fields Emanuele Giuseppe Esposito
2021-05-21 17:10 ` Vladimir Sementsov-Ogievskiy
2021-05-25 10:18 ` Emanuele Giuseppe Esposito
2021-05-25 11:00 ` Vladimir Sementsov-Ogievskiy
2021-05-26 14:48 ` Paolo Bonzini
2021-05-26 17:18 ` Vladimir Sementsov-Ogievskiy
2021-05-28 10:24 ` Paolo Bonzini
2021-05-28 11:01 ` Paolo Bonzini
2021-05-28 11:52 ` Vladimir Sementsov-Ogievskiy
2021-05-28 12:44 ` Vladimir Sementsov-Ogievskiy
2021-05-20 13:47 ` [PATCH v2 0/7] block-copy: protect block-copy internal structures Vladimir Sementsov-Ogievskiy
2021-05-20 14:33 ` Emanuele Giuseppe Esposito
2021-05-27 10:31 ` Stefan Hajnoczi
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