diff --git a/block/raw-posix.c b/block/raw-posix.c index 91159c7887..87d888ed01 100644 --- a/block/raw-posix.c +++ b/block/raw-posix.c @@ -1776,6 +1776,40 @@ static BlockDriver bdrv_host_cdrom = { }; #endif /* __FreeBSD__ */ +#ifdef CONFIG_LINUX_AIO +/** + * Return the file descriptor for Linux AIO + * + * This function is a layering violation and should be removed when it becomes + * possible to call the block layer outside the global mutex. It allows the + * caller to hijack the file descriptor so I/O can be performed outside the + * block layer. + */ +int raw_get_aio_fd(BlockDriverState *bs) +{ + BDRVRawState *s; + + if (!bs->drv) { + return -ENOMEDIUM; + } + + if (bs->drv == bdrv_find_format("raw")) { + bs = bs->file; + } + + /* raw-posix has several protocols so just check for raw_aio_readv */ + if (bs->drv->bdrv_aio_readv != raw_aio_readv) { + return -ENOTSUP; + } + + s = bs->opaque; + if (!s->use_aio) { + return -ENOTSUP; + } + return s->fd; +} +#endif /* CONFIG_LINUX_AIO */ + static void bdrv_file_init(void) { /* diff --git a/include/block/block.h b/include/block/block.h index b81d200b03..0719339231 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -365,6 +365,15 @@ void bdrv_disable_copy_on_read(BlockDriverState *bs); void bdrv_set_in_use(BlockDriverState *bs, int in_use); int bdrv_in_use(BlockDriverState *bs); +#ifdef CONFIG_LINUX_AIO +int raw_get_aio_fd(BlockDriverState *bs); +#else +static inline int raw_get_aio_fd(BlockDriverState *bs) +{ + return -ENOTSUP; +} +#endif + enum BlockAcctType { BDRV_ACCT_READ, BDRV_ACCT_WRITE,