From 38ce902686b9b6d4d19bfde134b18f997192ba01 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Duval?= <jerome.duval@gmail.com>
Date: Mon, 20 May 2019 21:57:28 +0200
Subject: [PATCH] posix: add posix_fadvise(), only error checks.

should help for ports.

Change-Id: Id504bdb79cb68db4b615f58848e0e1a86ced8d2b
Reviewed-on: https://review.haiku-os.org/c/1467
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>
---
 headers/posix/fcntl.h              | 10 ++++++++++
 src/system/libroot/posix/fcntl.cpp | 20 ++++++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/headers/posix/fcntl.h b/headers/posix/fcntl.h
index d86ca2be4e..e16dd1634c 100644
--- a/headers/posix/fcntl.h
+++ b/headers/posix/fcntl.h
@@ -67,6 +67,14 @@
 #define AT_REMOVEDIR		0x04	/* unlinkat() */
 #define AT_EACCESS			0x08	/* faccessat() */
 
+/* file advisory information, unused by Haiku */
+#define POSIX_FADV_NORMAL		0	/* no advice */
+#define POSIX_FADV_SEQUENTIAL	1	/* expect sequential access */
+#define POSIX_FADV_RANDOM		2	/* expect access in a random order */
+#define POSIX_FADV_WILLNEED		3	/* expect access in the near future */
+#define POSIX_FADV_DONTNEED		4	/* expect no access in the near future */
+#define POSIX_FADV_NOREUSE		5	/* expect access only once */
+
 /* advisory file locking */
 
 struct flock {
@@ -90,6 +98,8 @@ extern int	openat(int fd, const char *path, int openMode, ...);
 
 extern int	fcntl(int fd, int op, ...);
 
+extern int	posix_fadvise(int fd, off_t offset, off_t len, int advice);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/system/libroot/posix/fcntl.cpp b/src/system/libroot/posix/fcntl.cpp
index 1a82dec027..49f2f1ce9e 100644
--- a/src/system/libroot/posix/fcntl.cpp
+++ b/src/system/libroot/posix/fcntl.cpp
@@ -75,3 +75,23 @@ fcntl(int fd, int op, ...)
 
 	RETURN_AND_SET_ERRNO(error);
 }
+
+
+int
+posix_fadvise(int fd, off_t offset, off_t len, int advice)
+{
+	if (len < 0 || offset < 0 || advice < POSIX_FADV_NORMAL
+		|| advice > POSIX_FADV_NOREUSE) {
+		return EINVAL;
+	}
+
+	struct stat stat;
+	if (fstat(fd, &stat) < 0)
+		return EBADF;
+	if (S_ISFIFO(stat.st_mode))
+		return ESPIPE;
+
+	// Haiku does not use this information.
+	return 0;
+}
+