From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40098) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YXqvo-0007Tc-Nx for qemu-devel@nongnu.org; Tue, 17 Mar 2015 08:49:13 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YXqvn-0004vd-TR for qemu-devel@nongnu.org; Tue, 17 Mar 2015 08:49:12 -0400 From: Kevin Wolf Date: Tue, 17 Mar 2015 13:48:57 +0100 Message-Id: <1426596537-22616-1-git-send-email-kwolf@redhat.com> Subject: [Qemu-devel] [PATCH for-2.3] raw-posix: Deprecate aio=threads fallback without O_DIRECT List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: kwolf@redhat.com, famz@redhat.com, armbru@redhat.com, qemu-devel@nongnu.org Currently, if the user requests aio=native, but forgets to choose a cache mode that sets O_DIRECT, that request is silently ignored and raw falls back to aio=threads. Deprecate that behaviour so we can make it an error in future qemu versions. Signed-off-by: Kevin Wolf --- block/raw-posix.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/block/raw-posix.c b/block/raw-posix.c index f0b4488..929b6ae 100644 --- a/block/raw-posix.c +++ b/block/raw-posix.c @@ -503,6 +503,14 @@ static int raw_open_common(BlockDriverState *bs, QDict *options, error_setg_errno(errp, -ret, "Could not set AIO state"); goto fail; } + if (!s->use_aio && (bdrv_flags & BDRV_O_NATIVE_AIO)) { + fprintf(stderr, "WARNING: aio=native was specified for '%s', but " + "it requires cache.direct=on, which was not " + "specified. Falling back to aio=threads.\n" + " This will become an error condition in " + "future QEMU versions.\n", + bs->filename); + } #endif s->has_discard = true; -- 1.8.3.1