diff options
Diffstat (limited to 'block/graph-lock.c')
| -rw-r--r-- | block/graph-lock.c | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/block/graph-lock.c b/block/graph-lock.c index a92c6ae219..3bf2591dc4 100644 --- a/block/graph-lock.c +++ b/block/graph-lock.c @@ -110,8 +110,10 @@ static uint32_t reader_count(void) } #endif -void bdrv_graph_wrlock(void) +void bdrv_graph_wrlock(BlockDriverState *bs) { + AioContext *ctx = NULL; + GLOBAL_STATE_CODE(); /* * TODO Some callers hold an AioContext lock when this is called, which @@ -120,7 +122,22 @@ void bdrv_graph_wrlock(void) */ #if 0 assert(!qatomic_read(&has_writer)); +#endif + + /* + * Release only non-mainloop AioContext. The mainloop often relies on the + * BQL and doesn't lock the main AioContext before doing things. + */ + if (bs) { + ctx = bdrv_get_aio_context(bs); + if (ctx != qemu_get_aio_context()) { + aio_context_release(ctx); + } else { + ctx = NULL; + } + } +#if 0 /* Make sure that constantly arriving new I/O doesn't cause starvation */ bdrv_drain_all_begin_nopoll(); @@ -150,6 +167,10 @@ void bdrv_graph_wrlock(void) bdrv_drain_all_end(); #endif + + if (ctx) { + aio_context_acquire(bdrv_get_aio_context(bs)); + } } void bdrv_graph_wrunlock(void) |