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authorPaolo Bonzini <pbonzini@redhat.com>2017-06-05 14:38:58 +0200
committerFam Zheng <famz@redhat.com>2017-06-16 07:55:00 +0800
commit93001e9d87ae40e7569eb0ece0eb86d9c9582e41 (patch)
tree5a1566507d01274c72ed7fa3cca5c845a3a7e8d5 /block/throttle-groups.c
parent3b170dc86732539ebc5927880097d32d4f11df8c (diff)
throttle-groups: protect throttled requests with a CoMutex
Another possibility is to use tg->lock, which we're holding anyway in both schedule_next_request and throttle_group_co_io_limits_intercept. This would require open-coding the CoQueue however, so I've chosen this alternative. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20170605123908.18777-10-pbonzini@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
Diffstat (limited to 'block/throttle-groups.c')
-rw-r--r--block/throttle-groups.c12
1 files changed, 10 insertions, 2 deletions
diff --git a/block/throttle-groups.c b/block/throttle-groups.c
index 8bf1031efa..a181cb1dee 100644
--- a/block/throttle-groups.c
+++ b/block/throttle-groups.c
@@ -270,8 +270,13 @@ static bool coroutine_fn throttle_group_co_restart_queue(BlockBackend *blk,
bool is_write)
{
BlockBackendPublic *blkp = blk_get_public(blk);
+ bool ret;
- return qemu_co_queue_next(&blkp->throttled_reqs[is_write]);
+ qemu_co_mutex_lock(&blkp->throttled_reqs_lock);
+ ret = qemu_co_queue_next(&blkp->throttled_reqs[is_write]);
+ qemu_co_mutex_unlock(&blkp->throttled_reqs_lock);
+
+ return ret;
}
/* Look for the next pending I/O request and schedule it.
@@ -340,7 +345,10 @@ void coroutine_fn throttle_group_co_io_limits_intercept(BlockBackend *blk,
if (must_wait || blkp->pending_reqs[is_write]) {
blkp->pending_reqs[is_write]++;
qemu_mutex_unlock(&tg->lock);
- qemu_co_queue_wait(&blkp->throttled_reqs[is_write], NULL);
+ qemu_co_mutex_lock(&blkp->throttled_reqs_lock);
+ qemu_co_queue_wait(&blkp->throttled_reqs[is_write],
+ &blkp->throttled_reqs_lock);
+ qemu_co_mutex_unlock(&blkp->throttled_reqs_lock);
qemu_mutex_lock(&tg->lock);
blkp->pending_reqs[is_write]--;
}