From 81cced6ebeb4419a78a8892ec7d7e28f5582d24a Mon Sep 17 00:00:00 2001
From: Rich Felker <dalias@aerifal.cx>
Date: Thu, 25 Jan 2024 12:02:34 -0500
Subject: [PATCH] add preadv2 and pwritev2 syscall wrappers, flag value macros

---
 include/sys/uio.h    |  7 +++++++
 src/linux/preadv2.c  | 17 +++++++++++++++++
 src/linux/pwritev2.c | 17 +++++++++++++++++
 3 files changed, 41 insertions(+)
 create mode 100644 src/linux/preadv2.c
 create mode 100644 src/linux/pwritev2.c

diff --git a/include/sys/uio.h b/include/sys/uio.h
index 90e5939e..8b5e3de7 100644
--- a/include/sys/uio.h
+++ b/include/sys/uio.h
@@ -39,6 +39,13 @@ ssize_t pwritev (int, const struct iovec *, int, off_t);
 #ifdef _GNU_SOURCE
 ssize_t process_vm_writev(pid_t, const struct iovec *, unsigned long, const struct iovec *, unsigned long, unsigned long);
 ssize_t process_vm_readv(pid_t, const struct iovec *, unsigned long, const struct iovec *, unsigned long, unsigned long);
+ssize_t preadv2 (int, const struct iovec *, int, off_t, int);
+ssize_t pwritev2 (int, const struct iovec *, int, off_t, int);
+#define RWF_HIPRI 0x00000001
+#define RWF_DSYNC 0x00000002
+#define RWF_SYNC 0x00000004
+#define RWF_NOWAIT 0x00000008
+#define RWF_APPEND 0x00000010
 #endif
 
 #ifdef __cplusplus
diff --git a/src/linux/preadv2.c b/src/linux/preadv2.c
new file mode 100644
index 00000000..5e7ab70f
--- /dev/null
+++ b/src/linux/preadv2.c
@@ -0,0 +1,17 @@
+#define _GNU_SOURCE
+#include <sys/uio.h>
+#include <unistd.h>
+#include "syscall.h"
+
+ssize_t preadv2(int fd, const struct iovec *iov, int count, off_t ofs, int flags)
+{
+#ifdef SYS_preadv
+	if (!flags) {
+		if (ofs==-1) return readv(fd, iov, count);
+		return syscall_cp(SYS_preadv, fd, iov, count,
+			(long)(ofs), (long)(ofs>>32));
+	}
+#endif
+	return syscall_cp(SYS_preadv2, fd, iov, count,
+		(long)(ofs), (long)(ofs>>32), flags);
+}
diff --git a/src/linux/pwritev2.c b/src/linux/pwritev2.c
new file mode 100644
index 00000000..ece90d7c
--- /dev/null
+++ b/src/linux/pwritev2.c
@@ -0,0 +1,17 @@
+#define _GNU_SOURCE
+#include <sys/uio.h>
+#include <unistd.h>
+#include "syscall.h"
+
+ssize_t pwritev2(int fd, const struct iovec *iov, int count, off_t ofs, int flags)
+{
+#ifdef SYS_pwritev
+	if (!flags) {
+		if (ofs==-1) return writev(fd, iov, count);
+		return syscall_cp(SYS_pwritev, fd, iov, count,
+			(long)(ofs), (long)(ofs>>32));
+	}
+#endif
+	return syscall_cp(SYS_pwritev2, fd, iov, count,
+		(long)(ofs), (long)(ofs>>32), flags);
+}