[Mono.Posix] Add FcntlCommand.F_OFD_{GETLK,SETLK,SETLKW} (#16571)

Add F_OFD_GETLK, F_OFD_SETLK and F_OFD_SETLKW to FcntlCommand. These
commmands are similar to F_GETLK, F_SETLK and F_SETLKW but operate on a
per-open-file-description lock instead of a per-process lock and avoid the
problem that the locks are released when close(dup(fd)) is called. See
https://lwn.net/Articles/586904/ for more information.

This commit also reruns create-native-map but keeps manual changes from
ed892ccf27849c082ce6ca46fa8b96d86ca7c329,
b522eab5ff5466debaacf9e971e26cfc464ebba5 and
22b6b9581418260397b701c17b16c3eb55136de7.

In [create-native-map.diff.txt](https://github.com/mono/mono/files/3557077/create-native-map.diff.txt) you can see the difference between the commited `map.[ch]` and the one `create-native-map.exe` wants to create:
- Manually inserted changes for NetBSD (`MAYMOVE` is turned into a negated `FIXED`)
- `Mono_Posix_ToSockaddrIn6()` and friends get skipped for `HOST_WIN32` (not sure why, when `sockaddr_in6` exists then `Mono_Posix_ToSockaddrIn6()` should work)
- At the bottom of `map.h` some functions are reordered and the parameters change (`const char*` vs. `char*`)

Running create-native-map.exe also moved some O_NOATIME-related stuff (from 8b9033e4d24115190c06f775d18ef3a40cbca876) to the correct position and added it to Mono_Posix_ToOpenFlags(), which I kept in the commit.

3 files changed, 153 insertions, 16 deletions

diff --git a/mcs/class/Mono.Posix/Mono.Posix_test.dll.sources b/mcs/class/Mono.Posix/Mono.Posix_test.dll.sources
index a2f290f8656..5aee212abe7 100644
--- a/mcs/class/Mono.Posix/Mono.Posix_test.dll.sources
+++ b/mcs/class/Mono.Posix/Mono.Posix_test.dll.sources
@@ -9,6 +9,7 @@ Mono.Unix/UnixPathTest.cs
 Mono.Unix/UnixSignalTest.cs
 Mono.Unix/UnixUserTest.cs
 Mono.Unix.Android/TestHelper.cs
+Mono.Unix.Native/OFDLockTest.cs
 Mono.Unix.Native/RealTimeSignumTests.cs
 Mono.Unix.Native/SocketTest.cs
 Mono.Unix.Native/StdlibTest.cs
diff --git a/mcs/class/Mono.Posix/Mono.Unix.Native/Syscall.cs b/mcs/class/Mono.Posix/Mono.Unix.Native/Syscall.cs
index 6cc67dda4b8..c9eb750d222 100644
--- a/mcs/class/Mono.Posix/Mono.Unix.Native/Syscall.cs
+++ b/mcs/class/Mono.Posix/Mono.Unix.Native/Syscall.cs
@@ -212,22 +212,25 @@ namespace Mono.Unix.Native {
 	[CLSCompliant (false)]
 	public enum FcntlCommand : int {
 		// Form /usr/include/bits/fcntl.h
-		F_DUPFD    =    0, // Duplicate file descriptor.
-		F_GETFD    =    1, // Get file descriptor flags.
-		F_SETFD    =    2, // Set file descriptor flags.
-		F_GETFL    =    3, // Get file status flags.
-		F_SETFL    =    4, // Set file status flags.
-		F_GETLK    =   12, // Get record locking info. [64]
-		F_SETLK    =   13, // Set record locking info (non-blocking). [64]
-		F_SETLKW   =   14, // Set record locking info (blocking). [64]
-		F_SETOWN   =    8, // Set owner of socket (receiver of SIGIO).
-		F_GETOWN   =    9, // Get owner of socket (receiver of SIGIO).
-		F_SETSIG   =   10, // Set number of signal to be sent.
-		F_GETSIG   =   11, // Get number of signal to be sent.
-		F_NOCACHE  =   48, // OSX: turn data caching off/on for this fd.
-		F_SETLEASE = 1024, // Set a lease.
-		F_GETLEASE = 1025, // Enquire what lease is active.
-		F_NOTIFY   = 1026, // Required notifications on a directory
+		F_DUPFD      =    0, // Duplicate file descriptor.
+		F_GETFD      =    1, // Get file descriptor flags.
+		F_SETFD      =    2, // Set file descriptor flags.
+		F_GETFL      =    3, // Get file status flags.
+		F_SETFL      =    4, // Set file status flags.
+		F_GETLK      =   12, // Get record locking info. [64]
+		F_SETLK      =   13, // Set record locking info (non-blocking). [64]
+		F_SETLKW     =   14, // Set record locking info (blocking). [64]
+		F_OFD_GETLK  =   36, // Get open file description locking info.
+		F_OFD_SETLK  =   37, // Set open file description locking info (non-blocking).
+		F_OFD_SETLKW =   38, // Set open file description locking info (blocking).
+		F_SETOWN     =    8, // Set owner of socket (receiver of SIGIO).
+		F_GETOWN     =    9, // Get owner of socket (receiver of SIGIO).
+		F_SETSIG     =   10, // Set number of signal to be sent.
+		F_GETSIG     =   11, // Get number of signal to be sent.
+		F_NOCACHE    =   48, // OSX: turn data caching off/on for this fd.
+		F_SETLEASE   = 1024, // Set a lease.
+		F_GETLEASE   = 1025, // Enquire what lease is active.
+		F_NOTIFY     = 1026, // Required notifications on a directory
 	}
 
 	[Map]
diff --git a/mcs/class/Mono.Posix/Test/Mono.Unix.Native/OFDLockTest.cs b/mcs/class/Mono.Posix/Test/Mono.Unix.Native/OFDLockTest.cs
new file mode 100644
index 00000000000..44f45fe0187
--- /dev/null
+++ b/mcs/class/Mono.Posix/Test/Mono.Unix.Native/OFDLockTest.cs
@@ -0,0 +1,133 @@
+//
+// Tests for FcntlCommand.F_OFD_{GETLK,SETLK,SETLKW}
+//
+// Authors:
+//  Steffen Kiess (kiess@ki4.de)
+//
+// Copyright (C) 2019 Steffen Kiess
+//
+
+using System;
+using System.IO;
+using System.Net;
+using System.Net.Sockets;
+using System.Runtime.InteropServices;
+
+using Mono.Unix;
+using Mono.Unix.Native;
+
+using NUnit.Framework;
+
+namespace MonoTests.Mono.Unix.Native
+{
+	[TestFixture, Category ("NotDotNet"), Category ("NotOnWindows"), Category ("NotOnMac")]
+	public class OFDLockTest {
+
+		string TempFolder;
+
+		[SetUp]
+		public void SetUp ()
+		{
+			TempFolder = Path.Combine (Path.GetTempPath (), this.GetType ().FullName);
+
+			if (Directory.Exists (TempFolder))
+				Directory.Delete (TempFolder, true);
+
+			Directory.CreateDirectory (TempFolder);
+		}
+
+		[TearDown]
+		public void TearDown()
+		{
+			if (Directory.Exists (TempFolder))
+				Directory.Delete (TempFolder, true);
+		}
+
+		[Test]
+		public void TestOFDLock ()
+		{
+			int fd1 = Syscall.open (TempFolder + "/testfile", OpenFlags.O_RDWR | OpenFlags.O_CREAT | OpenFlags.O_EXCL, FilePermissions.DEFFILEMODE);
+			if (fd1 < 0)
+				UnixMarshal.ThrowExceptionForLastError ();
+			int fd2 = Syscall.open (TempFolder + "/testfile", OpenFlags.O_RDWR);
+			if (fd2 < 0)
+				UnixMarshal.ThrowExceptionForLastError ();
+			int fd3 = Syscall.open (TempFolder + "/testfile", OpenFlags.O_RDWR);
+			if (fd3 < 0)
+				UnixMarshal.ThrowExceptionForLastError ();
+
+			// Get read lock for first 100 bytes on fd1
+			var flock1 = new Flock {
+				l_type = LockType.F_RDLCK,
+				l_whence = SeekFlags.SEEK_SET,
+				l_start = 0,
+				l_len = 100,
+			};
+			if (Syscall.fcntl (fd1, FcntlCommand.F_OFD_SETLKW, ref flock1) < 0) {
+				// Old kernels and non-linux systems should return EINVAL
+				if (Stdlib.GetLastError () == Errno.EINVAL)
+					Assert.Ignore ("F_OFD_SETLKW does not seem to be supported.");
+				UnixMarshal.ThrowExceptionForLastError ();
+			}
+
+			// Get read lock for first 100 bytes on fd2
+			var flock2 = new Flock {
+				l_type = LockType.F_RDLCK,
+				l_whence = SeekFlags.SEEK_SET,
+				l_start = 0,
+				l_len = 100,
+			};
+			if (Syscall.fcntl (fd2, FcntlCommand.F_OFD_SETLK, ref flock2) < 0)
+				UnixMarshal.ThrowExceptionForLastError ();
+
+			// Get write lock for remaining bytes on fd1
+			var flock3 = new Flock {
+				l_type = LockType.F_WRLCK,
+				l_whence = SeekFlags.SEEK_SET,
+				l_start = 100,
+				l_len = 0,
+			};
+			if (Syscall.fcntl (fd1, FcntlCommand.F_OFD_SETLK, ref flock3) < 0)
+				UnixMarshal.ThrowExceptionForLastError ();
+
+			// Close fd3, should not release lock
+			if (Syscall.close (fd3) < 0)
+				UnixMarshal.ThrowExceptionForLastError ();
+			
+			// Get lock status for byte 150 from fd2
+			var flock4 = new Flock {
+				l_type = LockType.F_RDLCK,
+				l_whence = SeekFlags.SEEK_SET,
+				l_start = 150,
+				l_len = 1,
+			};
+			if (Syscall.fcntl (fd2, FcntlCommand.F_OFD_GETLK, ref flock4) < 0)
+				UnixMarshal.ThrowExceptionForLastError ();
+			// There should be a conflicting write lock
+			Assert.AreEqual (LockType.F_WRLCK, flock4.l_type);
+
+			// Get write byte 0 on fd1, should fail with EAGAIN
+			var flock5 = new Flock {
+				l_type = LockType.F_WRLCK,
+				l_whence = SeekFlags.SEEK_SET,
+				l_start = 0,
+				l_len = 1,
+			};
+			var res = Syscall.fcntl (fd1, FcntlCommand.F_OFD_SETLK, ref flock5);
+			Assert.AreEqual (-1, res);
+			Assert.AreEqual (Errno.EAGAIN, Stdlib.GetLastError ());
+			
+			if (Syscall.close (fd1) < 0)
+				UnixMarshal.ThrowExceptionForLastError ();
+			if (Syscall.close (fd2) < 0)
+				UnixMarshal.ThrowExceptionForLastError ();
+		}
+	}
+}
+
+// vim: noexpandtab
+// Local Variables: 
+// tab-width: 4
+// c-basic-offset: 4
+// indent-tabs-mode: t
+// End: