From ed6e2161715c527330f936d44af4c547f25f687e Mon Sep 17 00:00:00 2001 From: Nishanth Aravamudan Date: Fri, 22 Jun 2018 12:37:00 -0700 Subject: linux-aio: properly bubble up errors from initialization laio_init() can fail for a couple of reasons, which will lead to a NULL pointer dereference in laio_attach_aio_context(). To solve this, add a aio_setup_linux_aio() function which is called early in raw_open_common. If this fails, propagate the error up. The signature of aio_get_linux_aio() was not modified, because it seems preferable to return the actual errno from the possible failing initialization calls. Additionally, when the AioContext changes, we need to associate a LinuxAioState with the new AioContext. Use the bdrv_attach_aio_context callback and call the new aio_setup_linux_aio(), which will allocate a new AioContext if needed, and return errors on failures. If it fails for any reason, fallback to threaded AIO with an error message, as the device is already in-use by the guest. Add an assert that aio_get_linux_aio() cannot return NULL. Signed-off-by: Nishanth Aravamudan Message-id: 20180622193700.6523-1-naravamudan@digitalocean.com Signed-off-by: Stefan Hajnoczi --- include/block/aio.h | 3 +++ include/block/raw-aio.h | 2 +- 2 files changed, 4 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/block/aio.h b/include/block/aio.h index ae6f354..f08630c 100644 --- a/include/block/aio.h +++ b/include/block/aio.h @@ -381,6 +381,9 @@ GSource *aio_get_g_source(AioContext *ctx); /* Return the ThreadPool bound to this AioContext */ struct ThreadPool *aio_get_thread_pool(AioContext *ctx); +/* Setup the LinuxAioState bound to this AioContext */ +struct LinuxAioState *aio_setup_linux_aio(AioContext *ctx, Error **errp); + /* Return the LinuxAioState bound to this AioContext */ struct LinuxAioState *aio_get_linux_aio(AioContext *ctx); diff --git a/include/block/raw-aio.h b/include/block/raw-aio.h index 0e717fd..8d698cc 100644 --- a/include/block/raw-aio.h +++ b/include/block/raw-aio.h @@ -43,7 +43,7 @@ /* linux-aio.c - Linux native implementation */ #ifdef CONFIG_LINUX_AIO typedef struct LinuxAioState LinuxAioState; -LinuxAioState *laio_init(void); +LinuxAioState *laio_init(Error **errp); void laio_cleanup(LinuxAioState *s); int coroutine_fn laio_co_submit(BlockDriverState *bs, LinuxAioState *s, int fd, uint64_t offset, QEMUIOVector *qiov, int type); -- cgit v1.1