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 --- util/async.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) (limited to 'util/async.c') diff --git a/util/async.c b/util/async.c index 03f62787f2..05979f8014 100644 --- a/util/async.c +++ b/util/async.c @@ -323,14 +323,22 @@ ThreadPool *aio_get_thread_pool(AioContext *ctx) } #ifdef CONFIG_LINUX_AIO -LinuxAioState *aio_get_linux_aio(AioContext *ctx) +LinuxAioState *aio_setup_linux_aio(AioContext *ctx, Error **errp) { if (!ctx->linux_aio) { - ctx->linux_aio = laio_init(); - laio_attach_aio_context(ctx->linux_aio, ctx); + ctx->linux_aio = laio_init(errp); + if (ctx->linux_aio) { + laio_attach_aio_context(ctx->linux_aio, ctx); + } } return ctx->linux_aio; } + +LinuxAioState *aio_get_linux_aio(AioContext *ctx) +{ + assert(ctx->linux_aio); + return ctx->linux_aio; +} #endif void aio_notify(AioContext *ctx) -- cgit v1.2.3-55-g7522