From patchwork Tue Jul 20 16:09:37 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: Error on O_DIRECT for physical CDROM/DVD drives From: Jes Sorensen X-Patchwork-Id: 59343 Message-Id: <1279642177-21229-1-git-send-email-Jes.Sorensen@redhat.com> To: qemu-devel@nongnu.org Cc: Date: Tue, 20 Jul 2010 18:09:37 +0200 From: Jes Sorensen O_DIRECT (cache=none) requires sector alignment, however the physical sector size of CDROM/DVD drives is 2048, as opposed to most disk devices which use 512. QEMU is hard coding 512 all over the place, so allowing O_DIRECT for CDROM/DVD devices does not work. Exit with an error! Signed-off-by: Jes Sorensen --- block/raw-posix.c | 5 +++++ 1 files changed, 5 insertions(+), 0 deletions(-) diff --git a/block/raw-posix.c b/block/raw-posix.c index 291699f..1b840c4 100644 --- a/block/raw-posix.c +++ b/block/raw-posix.c @@ -1139,6 +1139,11 @@ static int cdrom_open(BlockDriverState *bs, const char *filename, int flags) BDRVRawState *s = bs->opaque; s->type = FTYPE_CD; + if (flags & BDRV_O_NOCACHE) { + fprintf(stderr, "O_DIRECT (cache=none) for CDROM/DVD device (%s) " + "is unsupported\n", filename); + exit(1); + } /* open will not fail even if no CD is inserted, so add O_NONBLOCK */ return raw_open_common(bs, filename, flags, O_NONBLOCK);