diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2017-06-05 14:38:58 +0200 |
|---|---|---|
| committer | Fam Zheng <famz@redhat.com> | 2017-06-16 07:55:00 +0800 |
| commit | 93001e9d87ae40e7569eb0ece0eb86d9c9582e41 (patch) | |
| tree | 5a1566507d01274c72ed7fa3cca5c845a3a7e8d5 /block | |
| parent | 3b170dc86732539ebc5927880097d32d4f11df8c (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')
| -rw-r--r-- | block/block-backend.c | 1 | ||||
| -rw-r--r-- | block/throttle-groups.c | 12 |
2 files changed, 11 insertions, 2 deletions
diff --git a/block/block-backend.c b/block/block-backend.c index 69d0e11466..738882dd2e 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -216,6 +216,7 @@ BlockBackend *blk_new(uint64_t perm, uint64_t shared_perm) blk->shared_perm = shared_perm; blk_set_enable_write_cache(blk, true); + qemu_co_mutex_init(&blk->public.throttled_reqs_lock); qemu_co_queue_init(&blk->public.throttled_reqs[0]); qemu_co_queue_init(&blk->public.throttled_reqs[1]); 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]--; } |