diff --git a/MAINTAINERS b/MAINTAINERS index 9277fbf128890c329f3571253a51e651918a4186..d26141277d77aa11bfb027e9ae418ed381067368 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -998,6 +998,7 @@ T: git git://repo.or.cz/qemu/kevin.git block Block I/O path M: Stefan Hajnoczi +M: Fam Zheng L: qemu-block@nongnu.org S: Supported F: async.c diff --git a/block/io.c b/block/io.c index c4869b96c502a633dba0e68ac5ddf074b7a15d10..a7dbf85b19a3ec804608839cc60f42598d4004cc 100644 --- a/block/io.c +++ b/block/io.c @@ -253,6 +253,47 @@ static void bdrv_drain_recurse(BlockDriverState *bs) } } +typedef struct { + Coroutine *co; + BlockDriverState *bs; + QEMUBH *bh; + bool done; +} BdrvCoDrainData; + +static void bdrv_co_drain_bh_cb(void *opaque) +{ + BdrvCoDrainData *data = opaque; + Coroutine *co = data->co; + + qemu_bh_delete(data->bh); + bdrv_drain(data->bs); + data->done = true; + qemu_coroutine_enter(co, NULL); +} + +void coroutine_fn bdrv_co_drain(BlockDriverState *bs) +{ + BdrvCoDrainData data; + + /* Calling bdrv_drain() from a BH ensures the current coroutine yields and + * other coroutines run if they were queued from + * qemu_co_queue_run_restart(). */ + + assert(qemu_in_coroutine()); + data = (BdrvCoDrainData) { + .co = qemu_coroutine_self(), + .bs = bs, + .done = false, + .bh = aio_bh_new(bdrv_get_aio_context(bs), bdrv_co_drain_bh_cb, &data), + }; + qemu_bh_schedule(data.bh); + + qemu_coroutine_yield(); + /* If we are resumed from some other event (such as an aio completion or a + * timer callback), it is a bug in the caller that should be fixed. */ + assert(data.done); +} + /* * Wait for pending requests to complete on a single BlockDriverState subtree, * and suspend block driver's internal I/O until next request arrives. @@ -269,6 +310,10 @@ void bdrv_drain(BlockDriverState *bs) bool busy = true; bdrv_drain_recurse(bs); + if (qemu_in_coroutine()) { + bdrv_co_drain(bs); + return; + } while (busy) { /* Keep iterating */ bdrv_flush_io_queue(bs); diff --git a/block/mirror.c b/block/mirror.c index f64db1a69b7ccd5bc8797467a0fd961cd0dcab69..c2cfc1a5ef5516dfb1db0ae32fba05fa3a84b3c7 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -650,7 +650,7 @@ static void coroutine_fn mirror_run(void *opaque) * mirror_populate runs. */ trace_mirror_before_drain(s, cnt); - bdrv_drain(bs); + bdrv_co_drain(bs); cnt = bdrv_get_dirty_count(s->dirty_bitmap); } diff --git a/include/block/block.h b/include/block/block.h index 6a39f946f52840f9e60e6806a5ab32871b6d1976..3a731377db0663594a1809252142c4a24672b913 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -372,6 +372,7 @@ int bdrv_flush(BlockDriverState *bs); int coroutine_fn bdrv_co_flush(BlockDriverState *bs); void bdrv_close_all(void); void bdrv_drain(BlockDriverState *bs); +void coroutine_fn bdrv_co_drain(BlockDriverState *bs); void bdrv_drain_all(void); int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors);