Add some notes about Linux AIO explaining why we don't use AIO in
some situations.
Signed-off-by: Frediano Ziglio <freddy77@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
}
#ifdef CONFIG_LINUX_AIO
+ /*
+ * Currently Linux do AIO only for files opened with O_DIRECT
+ * specified so check NOCACHE flag too
+ */
if ((bdrv_flags & (BDRV_O_NOCACHE|BDRV_O_NATIVE_AIO)) ==
(BDRV_O_NOCACHE|BDRV_O_NATIVE_AIO)) {
case QEMU_AIO_READ:
io_prep_preadv(iocbs, fd, qiov->iov, qiov->niov, offset);
break;
+ /* Currently Linux kernel does not support other operations */
default:
fprintf(stderr, "%s: invalid AIO request type 0x%x.\n",
__func__, type);