v4.19.13 snapshot.
diff --git a/include/uapi/linux/aio_abi.h b/include/uapi/linux/aio_abi.h
new file mode 100644
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--- /dev/null
+++ b/include/uapi/linux/aio_abi.h
@@ -0,0 +1,111 @@
+/* include/linux/aio_abi.h
+ *
+ * Copyright 2000,2001,2002 Red Hat.
+ *
+ * Written by Benjamin LaHaise <bcrl@kvack.org>
+ *
+ * Distribute under the terms of the GPLv2 (see ../../COPYING) or under
+ * the following terms.
+ *
+ * Permission to use, copy, modify, and distribute this software and its
+ * documentation is hereby granted, provided that the above copyright
+ * notice appears in all copies. This software is provided without any
+ * warranty, express or implied. Red Hat makes no representations about
+ * the suitability of this software for any purpose.
+ *
+ * IN NO EVENT SHALL RED HAT BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,
+ * SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF
+ * THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF RED HAT HAS BEEN ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * RED HAT DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND
+ * RED HAT HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
+ * ENHANCEMENTS, OR MODIFICATIONS.
+ */
+#ifndef __LINUX__AIO_ABI_H
+#define __LINUX__AIO_ABI_H
+
+#include <linux/types.h>
+#include <linux/fs.h>
+#include <asm/byteorder.h>
+
+typedef __kernel_ulong_t aio_context_t;
+
+enum {
+ IOCB_CMD_PREAD = 0,
+ IOCB_CMD_PWRITE = 1,
+ IOCB_CMD_FSYNC = 2,
+ IOCB_CMD_FDSYNC = 3,
+ /* 4 was the experimental IOCB_CMD_PREADX */
+ IOCB_CMD_POLL = 5,
+ IOCB_CMD_NOOP = 6,
+ IOCB_CMD_PREADV = 7,
+ IOCB_CMD_PWRITEV = 8,
+};
+
+/*
+ * Valid flags for the "aio_flags" member of the "struct iocb".
+ *
+ * IOCB_FLAG_RESFD - Set if the "aio_resfd" member of the "struct iocb"
+ * is valid.
+ */
+#define IOCB_FLAG_RESFD (1 << 0)
+#define IOCB_FLAG_IOPRIO (1 << 1)
+
+/* read() from /dev/aio returns these structures. */
+struct io_event {
+ __u64 data; /* the data field from the iocb */
+ __u64 obj; /* what iocb this event came from */
+ __s64 res; /* result code for this event */
+ __s64 res2; /* secondary result */
+};
+
+/*
+ * we always use a 64bit off_t when communicating
+ * with userland. its up to libraries to do the
+ * proper padding and aio_error abstraction
+ */
+
+struct iocb {
+ /* these are internal to the kernel/libc. */
+ __u64 aio_data; /* data to be returned in event's data */
+
+#if defined(__BYTE_ORDER) ? __BYTE_ORDER == __LITTLE_ENDIAN : defined(__LITTLE_ENDIAN)
+ __u32 aio_key; /* the kernel sets aio_key to the req # */
+ __kernel_rwf_t aio_rw_flags; /* RWF_* flags */
+#elif defined(__BYTE_ORDER) ? __BYTE_ORDER == __BIG_ENDIAN : defined(__BIG_ENDIAN)
+ __kernel_rwf_t aio_rw_flags; /* RWF_* flags */
+ __u32 aio_key; /* the kernel sets aio_key to the req # */
+#else
+#error edit for your odd byteorder.
+#endif
+
+ /* common fields */
+ __u16 aio_lio_opcode; /* see IOCB_CMD_ above */
+ __s16 aio_reqprio;
+ __u32 aio_fildes;
+
+ __u64 aio_buf;
+ __u64 aio_nbytes;
+ __s64 aio_offset;
+
+ /* extra parameters */
+ __u64 aio_reserved2; /* TODO: use this for a (struct sigevent *) */
+
+ /* flags for the "struct iocb" */
+ __u32 aio_flags;
+
+ /*
+ * if the IOCB_FLAG_RESFD flag of "aio_flags" is set, this is an
+ * eventfd to signal AIO readiness to
+ */
+ __u32 aio_resfd;
+}; /* 64 bytes */
+
+#undef IFBIG
+#undef IFLITTLE
+
+#endif /* __LINUX__AIO_ABI_H */
+