From: Stefan Hajnoczi <stefa...@redhat.com>
The following O_DIRECT read from a <512 byte file fails:
$ truncate -s 320 test.img
$ qemu-io -n -c 'read -P 0 0 512' test.img
qemu-io: can't open device test.img: Could not read image for determining its
format: Invalid argument
Note that qemu-io completes successfully without the -n (O_DIRECT)
option.
This patch fixes qemu-iotests ./check -nocache -vmdk 059.
Cc: qemu-sta...@nongnu.org
Suggested-by: Kevin Wolf <kw...@redhat.com>
Reported-by: Markus Armbruster <arm...@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com>
Signed-off-by: Kevin Wolf <kw...@redhat.com>
(cherry picked from commit 61ed73cff427206b3a959b18a4877952f566279b)
Signed-off-by: Michael Roth <mdr...@linux.vnet.ibm.com>
---
block/raw-posix.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/block/raw-posix.c b/block/raw-posix.c
index 8e9758e..87fc170 100644
--- a/block/raw-posix.c
+++ b/block/raw-posix.c
@@ -747,6 +747,15 @@ static ssize_t handle_aiocb_rw_linear(RawPosixAIOData
*aiocb, char *buf)
}
if (len == -1 && errno == EINTR) {
continue;
+ } else if (len == -1 && errno == EINVAL &&
+ (aiocb->bs->open_flags & BDRV_O_NOCACHE) &&
+ !(aiocb->aio_type & QEMU_AIO_WRITE) &&
+ offset > 0) {
+ /* O_DIRECT pread() may fail with EINVAL when offset is unaligned
+ * after a short read. Assume that O_DIRECT short reads only occur
+ * at EOF. Therefore this is a short read, not an I/O error.
+ */
+ break;
} else if (len == -1) {
offset = -errno;
break;
--
1.9.1
