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authorStefan Hajnoczi <stefanha@redhat.com>2014-08-21 13:44:07 +0100
committerKevin Wolf <kwolf@redhat.com>2014-08-22 11:00:56 +0200
commit61ed73cff427206b3a959b18a4877952f566279b (patch)
treecb2d7b74168ca5023b3359df57de5eb0f2781d96
parentd832fb4d66ead62da4af7e44cce34cd939e865e1 (diff)
downloadqemu-arm-61ed73cff427206b3a959b18a4877952f566279b.tar.gz
raw-posix: fix O_DIRECT short reads
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-stable@nongnu.org Suggested-by: Kevin Wolf <kwolf@redhat.com> Reported-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
-rw-r--r--block/raw-posix.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/block/raw-posix.c b/block/raw-posix.c
index 5c745b9a18..d737f3a0c5 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;