diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/block/block.h | 26 | ||||
| -rw-r--r-- | include/block/block_int.h | 17 |
2 files changed, 40 insertions, 3 deletions
diff --git a/include/block/block.h b/include/block/block.h index 84257ab940..b7dc7d54ae 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -337,9 +337,29 @@ void bdrv_drain_all(void); #define BDRV_POLL_WHILE(bs, cond) ({ \ bool waited_ = false; \ BlockDriverState *bs_ = (bs); \ - while ((cond)) { \ - aio_poll(bdrv_get_aio_context(bs_), true); \ - waited_ = true; \ + AioContext *ctx_ = bdrv_get_aio_context(bs_); \ + if (aio_context_in_iothread(ctx_)) { \ + while ((cond)) { \ + aio_poll(ctx_, true); \ + waited_ = true; \ + } \ + } else { \ + assert(qemu_get_current_aio_context() == \ + qemu_get_aio_context()); \ + /* Ask bdrv_dec_in_flight to wake up the main \ + * QEMU AioContext. Extra I/O threads never take \ + * other I/O threads' AioContexts (see for example \ + * block_job_defer_to_main_loop for how to do it). \ + */ \ + assert(!bs_->wakeup); \ + bs_->wakeup = true; \ + while ((cond)) { \ + aio_context_release(ctx_); \ + aio_poll(qemu_get_aio_context(), true); \ + aio_context_acquire(ctx_); \ + waited_ = true; \ + } \ + bs_->wakeup = false; \ } \ waited_; }) diff --git a/include/block/block_int.h b/include/block/block_int.h index 1044dfef43..e7ff58419c 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -475,6 +475,8 @@ struct BlockDriverState { unsigned int in_flight; unsigned int serialising_in_flight; + bool wakeup; + /* Offset after the highest byte written to */ uint64_t wr_highest_offset; @@ -633,6 +635,21 @@ void bdrv_remove_aio_context_notifier(BlockDriverState *bs, void (*aio_context_detached)(void *), void *opaque); +/** + * bdrv_wakeup: + * @bs: The BlockDriverState for which an I/O operation has been completed. + * + * Wake up the main thread if it is waiting on BDRV_POLL_WHILE. During + * synchronous I/O on a BlockDriverState that is attached to another + * I/O thread, the main thread lets the I/O thread's event loop run, + * waiting for the I/O operation to complete. A bdrv_wakeup will wake + * up the main thread if necessary. + * + * Manual calls to bdrv_wakeup are rarely necessary, because + * bdrv_dec_in_flight already calls it. + */ +void bdrv_wakeup(BlockDriverState *bs); + #ifdef _WIN32 int is_windows_drive(const char *filename); #endif |